Abstract: Thyroid-stimulating hormone (TSH) controls thyroid growth and hormone secretion through binding to its G protein-coupled receptor (TSHR) and production of cyclic AMP (cAMP). Serum TSH is a sensitive indicator of thyroid function, and overt abnormalities in thyroid function lead to common endocrine disorders affecting approximately 10% of individuals over a life span. By genotyping 362,129 SNPs in 4,300 Sardinians, we identified a strong association (p = 1.3 x 10(-11)) between alleles of rs4704397 and circulating TSH levels; each additional copy of the minor A allele was associated with an increase of 0.13 muIU/ml in TSH. The single-nucleotide polymorphism (SNP) is located in intron 1 of PDE8B, encoding a high-affinity cAMP-specific phosphodiesterase. The association was replicated in 4,158 individuals, including additional Sardinians and two genetically distant cohorts from Tuscany and the Old Order Amish (overall p value = 1.9 x 10(-20)). In addition to association of TSH levels with SNPs in PDE8B, our genome scan provided evidence for association with PDE10A and several biologically interesting candidates in a focused analysis of 24 genes. In particular, we found evidence for association of TSH levels with SNPs in the THRB (rs1505287, p = 7.3 x 10(-5)), GNAQ (rs10512065, p = 2.0 x 10(-4)), TG (rs2252696, p = 2.2 x 10(-3)), POU1F1 (rs1976324, p = 3.9 x 10(-3)), PDE4D (rs27178, p = 8.3 x 10(-3)), and TSHR (rs4903957, p = 8.6 x 10(-3)) loci. Overall, the results suggest a primary effect of PDE8B variants on cAMP levels in the thyroid. This would affect production of T4 and T3 and feedback to alter TSH release by the pituitary. PDE8B may thus provide a candidate target for the treatment of thyroid dysfunction.

Abstract: Background: Amiodarone-induced thyrotoxicosis (AIT) is caused by excessive hormone synthesis and release (AIT I) or by a destructive process (AIT II). This differentiation has important therapeutic implications. Purpose: To evaluate 99mTc-sestaMIBI (MIBI) thyroid scintigraphy in addition to other diagnostic tools in the diagnosis and management of AIT. Subjects and methods: Thyroid 99mTcO4- and 99mTc-MIBI scintigraphies were performed in 20 consecutive AIT patients, along with a series of biochemical and instrumental investigations (measurement of thyrotropin, free thyroid hormones and thyroid autoantibodies; thyroid color flow Doppler sonography [CFDS] and thyroid radioiodine uptake [RAIU]). Results: On the basis instrumental and laboratory data (excluding thyroid 99mTc-MIBI scintigraphy) and follow-up, AIT patients could be subdivided in 6 with AIT I, 10 with AIT II and 4 with indefinite forms of AIT (AIT Ind). 99mTc-MIBI uptake resulted normal/increased in all 6 patients with AIT I and absent in all 10 patients with AIT II. The remaining 4 patients with AIT Ind, showed in 2 cases low, patchy and persistent uptake and in the 2 evident MIBI uptake followed by a rapid wash out. MIBI scintigraphy was superior to all other diagnostic tools, including CFDS, (suggestive of AIT I in 3 patients with AIT II and of AIT II in 3 with AIT Ind) and RAIU, which was measurable in all patients with AIT I, bat also in 4/10 with AIT II. Conclusion: Thyroid MIBI scintigraphy may be proposed as easy and high effective tool for the differential diagnosis of different forms of AIT.

Abstract: OBJECTIVE: To investigate the clinical relevance of l-thyroxine (l-T(4)) substitution therapy in borderline hypothyroidism. DESIGN: To assess whether and to what extent administration of l-T(4) is able to modify systolic and diastolic function in patients with subclinical hypothyroidism and in subjects with autoimmune thyroiditis and normal serum TSH. METHODS: We studied 26 patients with classical Hashimoto's thyroiditis [18 with increased serum TSH (>3 mU/ml - Group A), and 8 with normal serum TSH (<3 mU/ml) - Group B]; a third group (C) included 13 healthy controls. All subjects underwent Pulsed Wave Tissue Doppler Imaging (PWTDI) to accurately quantify the global and regional left ventricular function. RESULTS: In both groups A and B we confirmed a significant impairment of systolic ejection (p<0.001 and p<0.05, respectively), a delay in diastolic relaxation (p<0.001 and p<0.05, respectively) and a decrease in the compliance to the ventricular filling (p<0.05). Administration of 50 microg/day of l-T(4) produced a progressive reduction of serum TSH (within the normal range) and normalization of all PWTDI parameters, which began after 6 months and finished after 12 months. CONCLUSION: Our data confirm previous evidence that subclinical hypothyroidism is associated with a cardiac dysfunction, even when this is very mild (i.e. with serum TSH still comprised in the normal range), and show that these abnormalities are reversible with l-T(4) replacement therapy.

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Abstract: OBJECTIVE: To test if sequence variations of the SYNTAXIN 1A (STX1A) gene contribute to the susceptibility to type 2 diabetes in a cohort of overweight/obese subjects. METHODS: A total of 717 overweight/obese individuals underwent oral glucose tolerance test and were stratified in four groups according to fasting and 2 h glucose levels (NGT, IGT, CGI, T2DM), representing the natural history of diabetes from normal glucose tolerance to overt disease. These subjects were analysed by a two-step genetic study. Functional analysis was performed by electrophoretic mobility shift assay (EMSA) and by supershift with CCAAT/enhancer-binding protein (C/EBP)beta antibody. RESULTS: Among the several sequence variations detected in the STX1A gene, the T allele of the -352 A>T single nucleotide polymorphism in the promoter was found in a lower frequency in the subset of individuals with greater impairment of insulin secretion (CGI). To confirm that a lower frequency of the T allele was associated with this condition, we genotyped a second group of 202 overweight/obese individuals with type 2 diabetes, and the frequency of the T allele was reduced in this group also (P<0.01). Logistic regression confirmed a protective odds ratio (0.49, P<0.01) for the T allele. The EMSA showed that the PRM -352 A allele binds transcription factors with lower affinity compared to the T allele, and incubation with C/EBPbeta antibody 'supershifted' the complex, indicating that C/EBPbeta had a different binding with the PRM -352T allele. CONCLUSION: A lower frequency of the PRM -352T allele of the STX1A gene was observed in overweight/obese subjects with impaired glucose regulation, particularly among individuals with combined glucose intolerance and overt diabetes. Both these groups have a greater defect in beta-cell function compared to normal and glucose intolerant subjects, and this association together with the functional study suggests a possible role of the PRM -352 A>T variant in insulin secretion.

Abstract: Background: A number of metabolic changes are caused by childhood obesity, including insulin-resistance, diabetes and dyslipidemia. To counteract them, lifestyle modification with changes in dietary habits and physical activity is the primary intervention. Anthropometric parameters may not identify all positive changes associated with lifestyle modifications, whereas circulating adipokines may represent an alternative as biomarkers. The aim of this study was to evaluate adiponectin and leptin levels as markers of positive metabolic outcomes in childhood obesity. Methods: Changes in clinical, anthropometric and metabolic parameters, including adiponectin and leptin, were assessed in 104 overweight and obese children before and after 1 year of lifestyle intervention. Obesity and overweight were defined according to the Italian BMI reference tables for age and sex. Fifty-four normal weight children were evaluated as controls. Forty-eight (47.5%) of the children returned for follow-up at 1 year. Results: Compared to normal weight children, overweight and obese subjects differed significantly at baseline for glycemia, insulinemia, HOMA-IR, adiponectinemia (5.8 microg/ml versus 18.2 microg/ml in controls), LDL-cholesterol, and triglycerides. These parameters were all higher in the overweight/obese children. At follow-up, most parameters improved in overweight/obese children. The most significant changes were observed in adiponectin concentration, which increased by 245% (p<0.0001), reaching the levels observed in normal weight children. Leptin levels showed changes unrelated to positive metabolic outcomes, remaining high at 1 year of follow-up in overweight/obese children. Regardless of changes in weight status, children with lifestyle intervention reported changes in HOMA-IR and in adiponectin associated with fat mass loss. Conclusions: After lifestyle intervention, adiponectin increased regardless of changes in weight, whereas no consistent changes was observed in serum leptin. Therefore, circulating adiponectin may represent a good biomarker to evaluate the efficacy of lifestyle intervention in overweight/obese children.

Abstract: Context: An increase in the prevalence of thyroid autoantibodies (ATA) was reported 6-8 years Chernobyl accident in radiation-exposed children and adolescents. Objective: To re-assess the effects of childhood radiation exposure on ATA and thyroid function 13-15 years after the accident. Design and Setting: We measured the anti-thyroglobulin (TgAb) and anti-thyroperoxidase (TPOAb) antibodies and thyrotropin (TSH) in 1433 sera collected between 1999 and 2001 from 13-17 year-old adolescents born between 1982 and October 1986 in paired contaminated and non-contaminated villages of Belarus, Ukraine and Russia (CIS countries). 1441 sera were collected from age- and sex-matched controls living in Denmark and Sardinia (Italy). Free thyroxine and free triiodothyronine were measured when TSH was abnormal. Results: TPOAb prevalence was higher in contaminated than in non-contaminated Belarusian children (6.4% vs. 2.4%, p=0.02), but lower than previously reported (11%) in a different contaminated Belarus village. No difference in TPOAb prevalence was found in Ukrainian and Russian villages. TgAb showed no difference between contaminated and not contaminated Belarus and Ukraine, while in Russia they showed a relative increase in the exposed subjects with respect to unexposed who showed an unexpectedly lower prevalence of TgAb. Besides radiation exposure, female gender was the only variable significantly correlated with ATA in all groups. ATA prevalence in non-exposed villages of CIS countries did not differ from that found in Sardinia and Denmark. With few exceptions, thyroid function was normal in all study groups. Conclusion: TPOAb prevalence in adolescents exposed to radioactive fallout was still increased in Belarus 13-15 years after the Chernobyl accident. This increase was less evident than previously reported and was not accompanied by thyroid dysfunction. Our data suggest that radioactive fallout elicited a transient autoimmune reaction, without triggering full-blown thyroid autoimmune disease. Longer observation periods are needed to exclude later effects.

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Abstract: BACKGROUND: Circulating antipituitary antibodies (APA) are markers of autoimmune hypophysitis, which may cause deficient pituitary function. The prevalence of APA in autoimmune thyroid disorders (AITD) is uncertain. OBJECTIVES: The aims of this study were 1) to evaluate APA prevalence in a large series of patients with AITD and non-AITD and 2) to investigate the functional significance of APA by assessing pituitary function in APA-positive patients. DESIGN AND SETTING: We conducted a health survey on consecutive AITD and non-AITD patients at a tertiary referral center (Department of Endocrinology, Pisa). PATIENTS: Subjects, including 1290 consecutive patients with thyroid disorders (961 AITD and 329 non-AITD) and 135 controls, were enrolled in the study. METHODS: APA (indirect immunofluorescence), free T(4), free T(3), TSH, and organ-specific autoantibodies were assayed in all patients. Functional pituitary evaluation was performed in most APA-positive patients. RESULTS: APA frequency was higher in AITD (11.4%) than in non-AITD (0.9%; P < 0.0001) patients; all control subjects had negative APA tests. APA were more frequently found in Hashimoto's thyroiditis (13%) than in Graves' disease (7.1%; P = 0.05). Of 110 APA-positive AITD patients, 20 (18.2%) had autoimmune polyglandular syndrome, whereas 90 (81.8%) had apparently isolated AITD. APA positivity increased percentage of autoimmune polyglandular syndrome in our series from 10.4 to 13.5%. Of 110 APA-positive patients, 102 were submitted to dynamic testing for functional pituitary assessment; 36 patients (35.2%) had mild or severe GH deficiency (GHD). No additional anterior pituitary hormone deficiencies were found; one patient had central diabetes insipidus. Pituitary abnormalities at magnetic resonance imaging were found in most APA-positive GHD patients. CONCLUSIONS: APA are frequently present in patients with AITD. Patients should be tested for APA because positive tests are associated with GHD.

Abstract: Objective: Genetic screening of RET proto-oncogene is a powerful tool for the early identification of familial cases of medullary thyroid carcinoma (MTC), comprising isolated familial thyroid medullary carcinoma (FMTC) and multiple endocrine neoplasia syndromes 2A (MEN-2A) and 2B (MEN-2B). We report the results obtained by RET mutation analysis of subjects living in Sardinia, an Italian island whose inhabitants display a peculiar genetic background due to geographic isolation and low immigration rate for several centuries. Design: Retrospective study reporting data on 67 patients referred during the last 5 years for RET analysis because affected by MTC or first degree relatives of MTC patients. Main outcome: Only three mutations were identified affecting codons 620 (exon 10), 634 (exon 11), and 804 (exon 14); surprisingly, the most prevalent mutation found was V804M (overall prevalence: 59%). This finding is quite different from previous studies carried out in other Caucasian and non-Caucasian populations, in which the frequency of the V804M mutation is consistently reported less than 5%. The phenotype associated to V804M mutation was mostly FMTC (16/17 cases = 94.1%), but in one case (5.9%) primary hyperparathyroidism was found, suggesting a MEN-2A. Conclusions: These results underline the importance of the genetic background in the distribution of RET mutations and should be taken into consideration when performing genetic evaluation of MTC patients.

Abstract: OBJECTIVE: The aim of the study was to evaluate the usefulness of calcitonin (CT) assay in fine-needle aspiration biopsy (FNAB) wash-out fluid alone or combined with cytology in the presurgical study of medullary thyroid carcinoma (MTC) patients with thyroid nodules (TNs) and of suspicious neck MTC recurrences/metastases. SUBJECTS AND METHODS: A total of 36 ultrasound-guided FNABs were performed in neck masses from 23 patients with borderline or high basal and pentagastrin-stimulated serum CT. Cytology and CT-FNAB were performed on a total of 18 TNs and three neck lymph nodes (LNs) from 12 patients examined before thyroidectomy, and on six suspicious local recurrences (LRs) and nine LNs from nine totally thyroidectomized MTC patients. On the basis of CT-FNAB values found in 15 non-MTC lesions, CT-FNAB more than 36 pg/ml was considered as indicative of MTC. RESULTS: All 21 positive CT-FNAB lesions (10 TNs, six LNs, and five LRs), 13 with positive cytology, were confirmed as MTC at histology. Of the 15 negative CT-FNAB suspicious masses (eight TNs, six LNs, and one LR), five displayed a benign lesion at histology. The remaining 10 cases, all with benign cytology, were not operated on, and no evidence of MTC was detected at follow-up. CT-FNAB reached 100% sensitivity and specificity for MTC, while cytology displayed 61.9% sensitivity and 80% specificity. CONCLUSIONS: Ultrasound-guided CT-FNAB was the best tool to identify primary MTC and LRs/node metastases in MTC operated subjects. This may have important implications in the management of MTC.

Abstract: OBJECTIVE: Lanreotide Autogel 120 mg (ATG120; Ipsen S.p.A, Milan, Italy) is a high-dose, sustained-release aqueous gel formulation, supplied in a prefilled syringe and given by deep subcutaneous injection. The aim of this study was to compare efficacy and tolerability of ATG120 given every 4-8 weeks with those of octreotide LAR (o-LAR) given every 4 weeks. DESIGN PATIENTS AND INTERVENTION: A phase III multicentre Italian open clinical study of 23 acromegalic patients (15 female, 8 male). All patients had received o-LAR for 6-18 months and, after 3 months wash out, ATG120 was given every 6 weeks for a total of four injections (Period 1). Then the interval between ATG120 injections was adjusted according to three different schemes: every 4, 6 or 8 weeks depending on GH levels (GH > 2.5 microg/l; 1 < GH <or= 2.5 microg/l; GH <or= 1 microg/l, respectively). ATG120 was given for a further two to three doses, with a final assessment (Period 2) at Week 34, 36 or 42. MEASUREMENTS: Hormonal (GH and IGF-I) and clinical efficacy and tolerability. RESULTS: ATG120 induced a significant GH decrease from 9.9 +/- 11.3 at baseline (Visit 1) to 3.5 +/- 5.7 at the end of Period 1 (P < 0.01) and to 3.8 +/- 5.7 microg/l at the final visit (P < 0.01). IGF-I also decreased from 544 +/- 312 at baseline (Visit 1) to 318 +/- 181 at Period 1 and to 356 +/- 187 microg/l at the final visit (both P < 0.05 vs. baseline). The frequency of ATG120 administrations was adjusted to every 4 weeks in 12 patients, every 6 weeks in 4 patients and every 8 weeks in 6 patients; 1 patient withdrew before the dose adjustment. Serum GH and IGF-I achieved at the end of Period 1 and Period 2 were similar to those reached with o-LAR. The number of patients who achieved GH < 2.5 microg/l was comparable between o-LAR (43%) and ATG120 at Period 1 (48%) and at Period 2 (62%). Normal IGF-I levels were recorded in 8 patients during o-LAR (35%), 11 during ATG Period 1 (48%) and 10 at the final visit (43%). Last, 4 patients showed a better response to ATG120 and 2 to o-LAR. CONCLUSIONS: Lanreotide Autogel 120 mg is an effective and well-tolerated therapy for acromegaly. In approximately half of patients ATG120 may be administered every 6-8 weeks, instead of every 4 weeks, without lost of efficacy.

Abstract: BACKGROUND: To estimate the prevalence of overweight and obesity among adolescents in Sardinia and to examine the association with several biological and geographic factors. METHODOLOGY: A cross-sectional study was performed in 3,946 unselected adolescents (2,011 boys, 1,935 girls; aged 11-15 years) attending the public secondary schools in 33 Sardinian municipalities: 28 semi-rural, 5 urban, sub-grouped according to their geographic location (mountain, hillside and plain). Oversized children were measured and their BMI defined as being above normal values according to parameters provided by the International Obesity Task Force (IOFT) by Cole et al. (BMI for age > or = 95th percentile). Relative risk for overweight and obesity was calculated using Poisson regression analysis: risks associated to each covariate were reciprocally adjusted. The 95% confidence interval (CI) of the estimated risk was calculated using Wald's formula (RR, RR = log(n) beta +/- 1.96 se(beta)). MAIN FINDINGS: The overall prevalence rate found for overweight and obesity was 14.9% (95% C.I.: 13.7-16.1%) and 3.7% (95% C.I. 3.1-4.3%), respectively. Overweight rate showed no association with gender, whereas belonging to the female sex constituted a significant protection against obesity. Increasing age in the range 12-14 years was protective against both overweight and obesity in the whole sample. A similar finding however was not observed for obesity in girls or overweight in boys, when considered separately. Boys, but not girls, living in urban areas displayed a modest though significant 20% increase in overweight and a 40% decrease in obesity risk. Living in a mountainous area conveyed a 30% decrease in risk of overweight and a 50% decrease in risk of obesity, when compared to living on the plains and hillside combined. However, the small sample size of study subjects living in mountainous areas generated extremely wide 95% confidence intervals, thereby preventing the drawing of any significant conclusions. CONCLUSION: In comparison with other surveys performed by the IOFT, Sardinian adolescents show a low prevalence rate for oversize, emphasizing a marked discrepancy with the general north-south rising trend of oversize observed throughout Europe. Geographic location, aesthetic or other age related factors seem to exert a different gender-specific influence on overweight and obesity. SIGNIFICANCE: The present report is cross sectional and the consequences of overweight and obesity on individuals over time are not traceable. However, the outcome of the study suggests the need to implement suitable policies and public health programs leading to increased awareness.

Abstract: Overt hypothyroidism (OH) and subclinical hypothyroidism (SH) are frequently found in the elderly. OH is associated with several functional cardiovascular abnormalities and increased risk of atherosclerosis resulting from hypertension associated to atherogenic lipid profile. Other potential atherogenic factors involved in OH are increased circulating C-reactive protein and homocysteine, increased arterial stiffness, endothelial dysfunction, and altered coagulation parameters. Similar (although mild) cardiovascular abnormalities are present in SH. Since all these abnormalities regress with levothyroxine (L-T4) administration, the cardiovascular benefits of replacement therapy in OH are not questionable, independently from the patient's age or the presence of coexisting cardiovascular disease. On the other hand, in spite of a very large number of studies, no consensus has been reached so far about the actual cardiovascular and/or general health impact of SH, and different recommendations have been recently made about screening and treatment of this condition. Although divergent results have been obtained in several epidemiological studies, recent meta-analyses provide evidence for a slight but significant increase of coronary heart disease (CHD) risk in SH. However, no agreement has been reached in favor or against active screening and/or treatment of mild thyroid failure. Moreover, L-T4 therapy is discouraged in aged subjects, because the increased oxygen consumption consequent to thyroid hormone administration could be dangerous, especially in the presence of coexisting CHD. In keeping with this concept are recent data showing reduced mortality risk in untreated mild hypothyroid subjects aged >85 years, suggesting that some degree of decreased thyroid activity at the tissue level might have favorable effects in the oldest-old. However, the effects of subtle thyroid dysfunction may be different in different age ranges. Since the main studies supporting a role for SH as a risk factor for atherosclerosis, cardiovascular disease, and all-cause mortality have been carried out in populations aged > or =55-60 years, mild thyroid failure could concur to increased cardiovascular risk in middle-aged and "young elderly" subjects, while being devoid of detrimental effects and possibly protective in the oldest-old. Further studies are needed to confirm this hypothesis.

Abstract: OBJECTIVE: To study prospectively the course of clinically relevant thyroid dysfunction in a cohort of patients on long-term lithium treatment. METHOD: Patients (no.=150) who had undergone a cross-sectional evaluation of their thyroid function in 1989, when they were at different stages of lithium treatment, were followed up for thyroid circulating thyroid antibodies, hypothyroidism, hyperthyroidism, and thyroidectomy, during a further period of lithium exposure of up to 15 yr. RESULTS: Annual rates of newly developed circulating thyroid antibodies and hypothyroidism were 1.7 and 1.5%, respectively. Subjects with thyroid antibodies had a higher chance of requiring substitution treatment with levothyroxine for hypothyroidism compared with subjects with no evidence of thyroid antibodies (6.4% annual rate compared to 0.8%; relative risk: 8.4; 95% confidence interval: 2.9-24.0). One case of hyperthyroidism was observed over 976 patient-yr. Three patients underwent thyroidectomy during followup (two for multinodular goiter and one for multicentric papillary carcinoma). CONCLUSIONS: Lithium may be associated with hypothyroidism in particular in the presence of circulating thyroid antibodies. Incidence of thyroid antibodies is comparable with that reported for the general population. Hyperthyroidism and thyroid cancer are rare.

Abstract: BACKGROUND: Amiodarone-induced thyrotoxicosis (AIT) may be caused by excessive thyroidal hormone synthesis and release (type 1) or by a destructive process (type 2). This differentiation is considered essential for therapeutic choice. PURPOSE: To evaluate the utility of color-flow Doppler sonography (CFDS) in the differential diagnosis and management of AIT. MATERIAL AND METHODS: The clinical and laboratory data, thyroid sonography (grayscale sonography [GSS], CFDS), thyroid radioiodine uptake (RAIU) and thyroid scintigraphy, treatment, and clinical outcome were retrospectively reviewed in 21 AIT patients. The CFDS pattern of thyroid nodules was separately described from that of the perinodular parenchyma, and AIT was classified as type 1 (increased blood flow) or type 2 (low/no blood flow). Type 1 AIT patients were treated with methimazole (alone or associated with potassium perchlorate), while type 2 patients were treated with prednisone or amiodarone withdrawal alone. RESULTS: Eleven patients with increased blood flow were considered as type 1, and 10 with low/no blood flow as type 2. Ten of the 11 patients in the first group showed a hypervascular nodular pattern, while one showed a hypervascular parenchymal pattern. Clinical diagnoses were toxic nodular goiter and Graves' disease, respectively. Of the 10 patients with low/no blood flow, six had normal thyroid volume, three small diffuse goiter, and one small multinodular goiter. The clinical outcome showed that 20 of the 21 patients were treatment responsive. CONCLUSION: CFDS is a useful tool in the differential diagnosis of AIT. This differentiation appeared to be of clinical relevance as regards therapeutic choice. Separate evaluation of parenchymal blood flow from that of nodules may prove beneficial in the diagnosis of underlying thyroid diseases in patients with type 1 AIT.

Abstract: OBJECTIVE: Familial isolated primary hyperparathyroidism (FIPH) can result from either incomplete expression of a syndromic form of familial primary hyperparathyroidism [multiple endocrine neoplasia type 1 (MEN 1), hyperparathyroidism-jaw tumour syndrome (HPT-JT) or familial hypocalciuric hypercalcaemia (FHH)] or still unrecognized causes. Design Genetic analyses of MEN1, HRPT2 and CASR genes in FIHP. PATIENTS: Seven well-characterized Italian kindreds with FIHP, with negative clinical features for MEN 1, HPT-JT and FHH. The mean age (+/- SD) at diagnosis was 45 +/- 17 years (range 18-70 years) in the probands and 42 +/- 18 years (range 15-69 years) in the other affected subjects. MEASUREMENTS: Direct sequencing of germline DNA of the MEN1, HRPT2 and CASR genes from probands. The region of interest was amplified in some family members. RESULTS: Germline MEN1 mutations were detected in three kindreds. Multiglandular involvement was found in all but one affected subject belonging to the three kindreds with MEN1 mutations. In these patients persistence/relapse of the disease was observed unless an extensive parathyroidectomy (excision of 3(1)/(2) glands) had been performed, with the exception of one patient, who is currently normocalcaemic 168 months after excision of two glands. No mutations of MEN1, HRPT2 and CASR genes were identified in the remaining four families. CONCLUSIONS: MEN1 genotyping appears worthwhile in FIHP families, as the finding of mutation(s) may predict multiglandular involvement and therefore have practical surgical implications, and prompt further investigation in the family, with the possibility of identifying new cases and beginning a programme of periodic surveillance for emergence of tumours in all carriers.

Abstract: OBJECTIVE: Serum thyroglobulin (Tg) is the marker of differentiated thyroid carcinoma (DTC) after total thyroidectomy, but its value is limited by the interference of anti-Tg antibodies (TgAb). Detection of Tg in fine-needle aspiration biopsy (Tg-FNAB) washout fluid is used to identify neck DTC recurrences/metastases, but the interference of serum TgAb in this procedure is unknown. PATIENTS AND METHODS: Seventy-three patients (41 after surgery for thyroid cancer and 32 with thyroid nodules) evaluated for suspicious cervical lymph nodes were retrospectively reviewed. Tg was assayed by immunoradiometric assay or chemiluminescent assay in ultrasound-guided FNAB used for cytology. Serum TgAb were detected by passive agglutination or chemiluminescent assay. On the basis of preliminary data obtained in lymphadenitis, Tg-FNAB more than 36 ng/ml and more than 1.7 ng/ml (in the presence or absence of thyroid gland, respectively) was considered as indicative of metastasis. RESULTS: In 51 TgAb-negative patients, Tg-FNAB was positive in 15 (12 with malignant and three with nondiagnostic cytology), all with histologically confirmed DTC metastases. Of the remaining 36 patients with negative Tg-FNAB, 30 had nonsuspicious and six had suspicious cytology. Histology of the latter showed four undifferentiated thyroid cancer metastases and two lymphadenitis. In 22 TgAb-positive patients, Tg-FNAB was positive in 14 (12 with malignant and two with nondiagnostic cytology), all with histologically confirmed DTC metastases. CONCLUSIONS: Clinical performance of Tg-FNAB appears to be not substantially affected by TgAb, and this procedure remains superior to cytology in the identification of DTC neck metastases. However, cytology should always be performed because, irrespective of TgAb, Tg is undetectable in FNAB from undifferentiated metastases.

Abstract: Rhabdoid tumor of the thyroid gland is a very rare neoplasm, characterized by significant metastatic potential. All of the 6 cases reported in the recent literature had poor outcomes. We report an additional case involving, to our knowledge, the oldest patient reported so far. A 67-year-old woman had a nodular goiter for all of her adult life and presented with a rapidly growing mass in the right lobe. Histologic examination showed a highly cellular neoplasm with a solid infiltrative growth pattern. Extracapsular invasion was evident. Rhabdoid cells were large, with abundant cytoplasm, eosinophilic inclusions, and eccentric nuclei containing distinct nucleoli. Immunohistochemistry identified vimentin, sarcomeric actin, myoglobin, and cytokeratin expression in the tumor cells; they were negative for desmin, thyroglobulin, and calcitonin. Scattered follicles with nuclear features of papillary thyroid carcinoma were detected; these cells were immunoreactive for thyroglobulin and TTF-1. Reverse transcriptase polymerase chain reaction using specific primers for RET/PTC1 and RET/PTC3 fusion genes identified a RET/PTC3 gene rearrangement in the rhabdoid tumor. Despite radiotherapy, the neoplasm rapidly progressed, with massive local and mediastinal metastasis leading to death 5 months after presentation. The hypothesis that rhabdoid tumor is a variant of anaplastic thyroid carcinoma is supported by the identification of a RET/PTC gene rearrangement, a feature of carcinomas of follicular cell derivation.

Abstract: OBJECTIVE: In subclinical hypothyroidism (SH), impaired diastolic function has been documented at rest and on effort, while systolic dysfunction has only been assessed on effort. DESIGN: The aim of the present study was: (a) to further assess systolic function at rest in SH; and (b) to ascertain whether cardiac dysfunction could precede TSH increase in euthyroid patients with a high risk of developing SH. METHODS: We studied 32 patients with classical Hashimoto's thyroiditis (22 with increased serum TSH (> 3 mU/ml - group A), and 10 with normal serum TSH (< 3 mU/ml - group B)); a third group (C), which included 13 healthy controls. All subjects underwent pulsed wave tissue Doppler imaging (PWTDI) to accurately quantify the global and regional left ventricular function. RESULTS: When compared with group C, PWTDI indices showed that in both groups A and B there was a significant impairment of systolic ejection (P < 0.001 and P < 0.05, respectively), a delay in diastolic relaxation (P < 0.001 and P < 0.05, respectively) and a decrease in the compliance to the ventricular filling (P < 0.05). Several significant correlations were found between PWTDI parameters and serum-free T(3) and T(4) and TSH concentrations. CONCLUSION: PWTDI is a sensitive technique that allows detection of both diastolic and systolic abnormalities, not only in patients with SH, but also in euthyroid subjects with a high risk of developing thyroid failure. Futhermore, the significant correlations of several PWTDI indices with serum FT(3) and TSH concentrations strongly support the concept of a continuum spectrum of a slight thyroid failure in autoimmune thyroiditis extending to subjects with serum TSH still within the normal range.

Abstract: OBJECTIVE: We assessed the association between thyroid autoimmunity and thyroid cancer in a retrospective series of unselected thyroid nodules submitted to fine-needle aspiration cytology (FNAC) to avoid the selection bias of surgical series. SUBJECTS AND METHODS: Ultrasound (US)-guided FNACs were obtained from 590 unselected consecutive patients with single thyroid nodules and positive (ATA + , n = 197) or negative (ATA - , n = 393) serum anti-thyroid antibody (ATA). Cytological results were classified in three classes of increased risk of malignancy: low risk or benign (class II); indeterminate risk (class III); and suspect or malignant (class IV). RESULTS: A higher prevalence of class III (28.9% vs 21.4%, P < 0.05) and class IV (18.8% vs 9.2%, P < 0.001) and lower prevalence of class II (52.3% vs 69.5%, P < 0.001) were found in ATA + vs ATA - nodules respectively. By multivariate logistic regression analysis ATA + conferred a significant risk (odds ratio (OR): 2.29 (95% confidence interval (CI): 1.39-3.76)) for class IV cytology independently from age and sex. In 106 patients where thyroidectomy was carried out, thyroid cancer was found in 54/61 (88.5%) patients with class IV nodules (with similar positive predictive value for cancer in ATA + (96.4%) and ATA- (81.8%) nodules), in 6/31 (19.3%) of class III nodules (all ATA - ) and in none of 14 class II nodules. Non-specific cytological atypias from hyperplastic nodules in lymphocytic thyroiditis probably accounted for the different prevalence of cancer in class III ATA + and ATA - nodules. Histologically proven thyroid cancer (mostly papillary) was then observed in a higher proportion (27/197 = 13.7%) of ATA + , when compared with ATA - nodules (33/393 = 8.4%, P = 0.044), but the significance of this finding is limited by the low number of class II nodules operated on. CONCLUSIONS: The presence of ATA + confers an increased risk of suspicious or malignant cytology in unselected thyroid nodules. Since ATA + is not responsible for increased false-positive class IV FNAC, our study provides indirect evidence supporting a significant association between thyroid carcinoma and thyroid autoimmunity, although further studies with a different design are needed for a definitive histological proof.

Abstract: OBJECTIVE: To evaluate the association between mood and anxiety disorders in Hashimoto disease and Euthyroid Goitre in a case control study. METHODS: Cases included 19 subjects with Hashimoto disease in euthyroid phase, 19 subjects with euthyroid goitre, 2 control groups each of 76 subjects matched (4/1) according to age and sex drawn from the data base of a community based sample. Psychiatric diagnoses were formulated using the International Composite Diagnostic Interview Simplified, according to DSM-IV criteria. All subjects underwent a complete thyroid evaluation including physical examination, thyroid echography and measure of serum free T4 (FT4), free T3 (FT3), thyroid-stimulating hormone (TSH) and anti-thyroid peroxidase autoantibodies (anti-TPO). RESULTS: Subjects with Hashimoto disease showed higher frequencies of lifetime Depressive Episode (OR = 6.6, C.L. 95% 1.2-25.7), Generalized Anxiety Disorders (OR = 4,9 Cl 95% 1.5-25.4) and Social Phobia (OR = 20.0, CL 95% 2.3-153.3) whilst no differences were found between subjects with goitre and controls. CONCLUSION: The study seems to confirm that risk for depressive disorders in subjects with thyroiditis is independent of the thyroid function detected by routine tests and indicates that not only mood but also anxiety disorders may be associated with Hashimoto disease.

Abstract: CONTEXT: Autoantibodies to adenohypophyseal endocrine cells or to vasopressin neurohypophyseal neurons have long been known. Conversely, autoimmune targeting of further hypothalamic-hypophyseal structures, such as the blood-brain barrier-deprived median eminence, has been little studied. OBJECTIVE AND METHODS: We studied a case of autoimmune polyendocrine syndrome type I with GH secretory deficiency, a distinctly rare event in autoimmune polyendocrine syndrome type I. We used rat and bovine tissue substrates to study autoantibodies against hypothalamic-hypophyseal nerve structures and endocrine cells. RESULTS: In the study case, circulating autoantibodies selectively decorated median eminence dopaminergic nerve terminals, as well as pituitary gonadotropes, but not GHRH nerve terminals or pituitary somatotropes. Such autoantibodies appeared de novo in parallel with the onset of GH secretory deficiency, whereas no median eminence labeling was found in patients suffering of idiopathic GH deficiency (n = 7) or in healthy controls (n = 23). CONCLUSIONS: The pathophysiological significance of our patient's autoantibodies remains to be confirmed. Nonetheless, the heterogeneous neuroendocrine structures of the median eminence are pointed out as potential immune targets, relevant to autoimmune polyendocrinopathy, as well as to a wide range of other conditions.

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Abstract: PURPOSE: The objective of this study was to retrospectively assess whether computerized gray-scale sonography can allow objective measurement of thyroid echogenicity in patients with Hashimoto's thyroiditis (HT) at various functional stages of the disease. METHODS: Of the 77 patients with HT who were included in our study, 28 had been euthyroid, 20 had had subclinical hypothyroidism, and 29 had had clinical hypothyroidism. Of those with clinical hypothyroidism, 6 had been untreated and 23 had been receiving L-thyroxine substitution therapy. Fifty volunteers without thyroid disease served as a control group. Thyroid echogenicity was evaluated by computerized gray-scale sonography as mean tissue density (MTD) +/- standard deviation; the echogenicity of the prethyroid muscles served as a control of the system variability. RESULTS: The MTD was significantly lower for the patients with HT (15.9 +/- 4) than for the control subjects (24.3 +/- 3; p < 0.05). Moreover, a significant difference was found between the MTD values of euthyroid patients with HT (18.9 +/- 3.4) and hypothyroid patients with HT analyzed either as a group (14.3 +/- 3.8) or separately for subclinical hypothyroidism (14.9 +/- 3.8) and clinical hypothyroidism (13.9 +/- 3.7; p < 0.05). The lowest MTD was found in patients with untreated clinical hypothyroidism (11.1 +/- 4.3), with a significant difference (p < 0.05) compared to all other groups of patients. Untreated patients with clinical hypothyroidism also showed the highest mean anti-thyroid peroxidase autoantibody levels (1,286 +/- 177 IU/ml versus 570 +/- 489 IU/ml for L-thyroxine-treated patients; p < 0.05), although no correlation between the MTD values and anti-thyroid peroxidase autoantibody levels was found in any group of patients. CONCLUSIONS: Computerized gray-scale sonography provides an objective measure of thyroid hypoechogenicity, which correlates well to the clinical stages of HT. Use of this modality may prove beneficial in the diagnosis and follow-up of patients with HT.

Abstract: PURPOSE: Brain perfusion abnormalities have recently been demonstrated by single-photon emission computed tomography (SPECT) in rare cases of severe Hashimoto's thyroiditis (HT) encephalopathy; moreover, some degree of subtle central nervous system (CNS) involvement has been hypothesised in HT, but no direct evidence has been provided so far. The aim of this study was to assess cortical brain perfusion in patients with euthyroid HT without any clinical evidence of CNS involvement by means of 99mTc-ECD brain SPECT. Sixteen adult patients with HT entered this study following informed consent. METHODS: The diagnosis was based on the coexistence of high titres of anti-thyroid auto-antibodies and diffuse hypoechogenicity of the thyroid on ultrasound in association with normal circulating thyroid hormone and TSH concentrations. Nine consecutive adult patients with non-toxic nodular goitre (NTNG) and ten healthy subjects matched for age and sex were included as control groups. All patients underwent 99mTc-ECD brain SPECT. Image assessment was both qualitative and semiquantitative. Semiquantitative analysis was performed by generation of four regions of interest (ROI) for each cerebral hemisphere--frontal, temporal, parietal and occipital--and one for each cerebellar hemisphere in order to evaluate cortical perfusion asymmetry. The Asymmetry Index (AI) was calculated to provide a measurement of both magnitude and direction of perfusion asymmetry. RESULTS: As assessed by visual examination, 99mTc-ECD cerebral distribution was irregular and patchy in HT patients, hypoperfusion being more frequently found in frontal lobes. AI revealed abnormalities in 12/16 HT patients, in three of the nine NTNG patients and in none of the normal controls. A significant difference in the mean AI was found between patients with HT and both patients with NTNG (p<0.003) and normal controls (p<0.001), when only frontal lobes were considered. CONCLUSION: These results show the high prevalence of brain perfusion abnormalities in euthyroid HT. These abnormalities are similar to those observed in cases of severe Hashimoto's encephalopathy and may suggest a higher than expected involvement of CNS in thyroid autoimmune disease.

Abstract: Pendred syndrome and the enlarged vestibular aqueduct (EVA) are considered phenotypic variations of the same entity due to mutations in the SLC26A4 (pendrin) gene. Pendred syndrome consists in sensorineural deafness, goiter and impaired thyroid hormone synthesis while in EVA thyroid function seems to be preserved. The aim of this study was to evaluate thyroid function and morphology and to look for mutations in the SLC26A4 gene in patients presented with EVA. Among 57 consecutive patients with sensorineural deafness 15 with EVA, as assessed by magnetic resonance imaging (MRI), were identified and studied. A complete evaluation of thyroid function including thyroid echography and perchlorate discharge test was carried out in all patients with EVA; all exons of the SLC26A4 gene were amplified from peripheral leukocytes and directly sequenced, using specific intronic primers. Out of 15 patients with EVA, goiter was present in 8 (53%), hypothyroidism in 7 (47%), increased serum thyroglobulin levels in 8 (53%) and a positive perchlorate discharge test in 10 (67%). Nine alleles of the SLC26A4 gene were mutated: 2 novel mutations (L465W and G497R) and 4 already known mutations (T410M, R409H, T505N and IVS1001+1G>A) were found. Four subjects were compound heterozygous and 1 heterozygous (G497R/wt). All patients harbouring mutations in the SLC26A4 gene had goiter and a positive perchlorate discharge test: 3 were slightly hypothyroid and 2 euthyroid. The remaining 10 patients had no mutations in the SLC26A4 gene: 4 of them were hypothyroid, 2 with goiter and positive perchlorate discharge test, 2 without goiter and with negative perchlorate discharge test. Two patients without mutations were euthyroid with positive perchlorate discharge test. Patients with mutations in the SLC26A4 gene had larger thyroid volume (p<0.002), higher serum thyroglobulin (Tg) levels (p<0.002) and greater radioiodine discharge after perchlorate (p=0.09) than patients without mutations. The results of the present study lend support to the concept that all patients with mutated SLC26A4 gene have abnormalities of thyroid function tests.

Abstract: BACKGROUND: To evaluate the association between mood and anxiety disorders and thyroid autoimmunity in a community sample. Methods: A community based sample of 222 subjects was examined. Psychiatric diagnoses were formulated using the International Composite Diagnostic Interview Simplified (CIDIS), according to DSM-IV criteria. All subjects underwent a complete thyroid evaluation including physical examination, thyroid echography and measure of serum free T4 (FT4), free T3 (FT3), thyroid-stimulating hormone (TSH) and anti-thyroid peroxidase autoantibodies (anti-TPO). RESULTS: 16.6% of the overall sample had an anti-TPO value above the normal cut-off. Subjects with at least one diagnosis of anxiety disorders (OR = 4.2, C.L. 95% 1.9-38.8) or mood disorders (OR = 2.9, Cl 95% 1.4-6.6, P < 0.011) were positive for serum anti-TPO more frequently than subjects without mood or anxiety disorders. A statistically significant association with anti-TPO+ was found in Anxiety Disorder Not Otherwise Specified (OR = 4.0, CL 95% 1.1-15.5), in Major Depressive Episode (OR = 2.7, CL 95% 1.1-6.7) and Depressive Disorder Not Otherwise Specified (OR = 4.4, S CL 95% 1-19.3). CONCLUSIONS: The study seems to suggest that individuals in the community with thyroid autoimmunity may be at high risk for mood and anxiety disorders. The psychiatric disorders and the autoimmune reaction seem to be rooted in a same (and not easy correctable) aberrancy in the immuno-endocrine system. Should our results be confirmed, the findings may be of great interest for future preventive and case finding projects.

Abstract: Germline mutations of the MEN 1 gene are responsible for multiple endocrine neoplasia type 1 (MEN 1), a dominantly inherited cancer syndrome characterized by tumors of the parathyroids, gastro-intestinal endocrine tissue, anterior pituitary and other endocrine tissues. We report on a 55-yr old woman, presenting with active acromegaly (due to GH-secreting microadenoma), associated to bilateral adrenal adenomatosis and Hürthle-cell thyroid neoplasia. No evidence of hyperparathyroidism or gastrin-secreting tumor was found. Peripheral blood genomic DNA was extracted, amplified by PCR, purified and analyzed by direct sequencing. The analysis revealed a heterozygous mutation in exon 4 of the MEN 1 gene: a G to A missense mutation at codon 229 (CGC-->CAC), which changes arginine to histidine. This mutation causes loss of the Hhal restriction site and can thus be employed for a rapid familiar screening. This case represents a newly recognized germline mutation of the MEN 1 gene.

Abstract: The aim of this paper is to briefly review some practical aspects of the relationship between thyroid function and several disorders of the hemostatic system in terms of bleeding and thrombosis. Thrombocytopenia, acquired hemophilia, hypercoagulability, cardioembolism and other biochemical coagulative and fibrinolytic abnormalities have been described in the past years both in hyper- and hypothyroidism. Since most of hyper- and hypothyroid conditions are the consequence of autoimmune thyroid disease (1), either deranged immune function, altered circulating thyroid hormone concentration, or both may concur in the pathogenesis of hemostatic disorders of potential crucial clinical impact. These aspects will be outlined and discussed in an attempt to give answers to some questions, often arising in the clinical approach.

Abstract: Gain-of-function RET mutations are responsible for multiple endocrine neoplasia syndromes (MEN) 2A and 2B and familial medullary thyroid carcinoma (FMTC), whereas loss-of-function mutations are found in Hirschsprung disease. We report a new RET point mutation [R694Q (CGG-->CAG)], serendipitously found in a 23-yr-old woman with hypothyroidism due to atrophic Hashimoto's thyroiditis and primary ovarian failure, without altered calcitonin secretion. Familial history and clinical and biochemical evaluation of first-degree relatives were negative for FMTC, MEN 2A and 2B, and Hirschsprung disease. Genetic analysis showed that the mutation was inherited from the mother, who was submitted 2 yr before to thyroidectomy for goitrous Hashimoto's thyroiditis. Histological revision and immunohistochemical studies documented normal C cell number and morphology. We cloned the mutation in an expression vector encoding a full-length RET protein. The construct was transiently expressed in 293T cells in parallel with a wild-type RET and a C634R MEN 2A-associated RET mutant. Proteins were harvested from transfected cells, and tyrosine phosphorylation levels were assayed. The mutation did not exert significant potentiating effects on RET kinase. A focus assay was also performed on NIH3T3 fibroblasts; the mutant did not exert significant transforming activity.In conclusion, a new RET mutation was found in two subjects without any evidence of MEN and FMTC. In keeping with clinical data, transfection studies confirmed lack of activating activity. This serendipitous discovery, apparently devoid of oncogenic potential, underscores the problems that may be encountered in genomic studies on RET.

Abstract: OBJECTIVE: Since brain perfusion abnormalities have been described by single-photon emission computed tomography in some autoimmune diseases, the aim of the present study was to evaluate the incidence of perfusion abnormalities by brain single-photon emission computed tomography in a group of coeliac disease patients, and to investigate whether gluten intake and associated autoimmune diseases may be considered risk factors in causing cerebral impairment. METHODS: Thirty-four adult coeliac patients (16 on a gluten-free diet and 18 on a gluten-containing diet, 18 (53%) with autoimmune diseases) underwent 99mTc-ethyl cysteinate dimer brain single-photon emission computed tomography and qualitative evaluation of brain perfusion was performed together with a semiquantitative estimation using the asymmetry index. Ten subjects on our database, matched for sex, age and ethnic group, who were proved normal by histology ofjejunal mucosa (four males and six females; median age 39 years, range 27-55 years), were included as control group. RESULTS: Twenty-four out of 34 patients (71%) showed brain single-photon emission computed tomography abnormalities confirmed by abnormal regional asymmetry index (>5%; range 5.8-18.5%). Topographic comparison of the brain areas showed that the more significant abnormalities were localised in frontal regions, and were significantly different from controls only in coeliac disease patients on unrestricted diet. The prevalence of single-photon emission computed tomography abnormalities was similar in coeliac disease patients with (74%) and without (69%) associated autoimmune disease. CONCLUSIONS: Abnormalities of brain perfusion seem common in coeliac disease. This phenomenon is similar to that previously described in other autoimmune diseases, but does not appear to be related to associated autoimmunity and, at least in the frontal region, may be improved by a gluten-free diet.

Abstract: Oncocytic cells are characterized by a greatly increased number of mitochondria that distend the cell cytoplasm and result in a distinctive granular appearance of the cell on conventional histology sections. Oncocytes are frequently found in metabolically active human tissues including the thyroid gland, and, as a general rule, when their proportion in a thyroid tumor is greater than 75% the tumor is referred to as oncocytic (Hürthle cell) adenoma or carcinoma. Such tumors represent a subset of thyroid lesions, and recently, both interphase fluorescence in situ hybridization (FISH) and comparative genomic hybridization (CGH) studies reported that they may show aneuploidy, with widespread numerical chromosomal alterations. In contrast, very few cases have been studied by conventional cytogenetic analysis. Whether the cells with chromosomal changes are the same as those with mitochondrial accumulation or whether lesions only partially composed of oncocytic cells also have cytogenetic alterations is unclear. To investigate the relationship between acquisition of the oncocytic phenotype and numerical chromosomal changes, we analyzed a random selection of thyroid lesions with (18 cases) and without (11 cases) morphological evidence of oncocytic differentiation. Lesions with oncocytes included hyperplastic nodules, adenomas, Hürthle cell tumors, and papillary carcinomas with lymphocytic stroma (Whartin-like tumors of the thyroid). Karyotypic changes were analyzed by cytogenetic analysis, FISH, or CGH, and the results were compared with in situ analysis of mitochondrial accumulation by immunofluorescence. A striking correlation between the presence of oncocytes and the presence of aneuploid katyotypes was seen in the oncocytic follicular thyroid nodules, but not in the oncocytic papillary tumors. Structural chromosome changes or normal karyotypes were observed in the lesions lacking oncocytic features. Extending the FICTION technique to the evaluation of a cytoplasmic antigen (mitochondrial membrane antigen), we pursued the simultaneous visualization of both mitochondrial increase and numerical chromosomal alterations, and showed that oncocytes of follicular lesions are prone to become aneuploid. Our data support the contention that follicular tumors composed of oncocytes should be regarded as a distinct subset.

Abstract: OBJECTIVE: To assess the relevance of (99m)Tc-SestaMIBI (MIBI) scan in the diagnostic evaluation of thyroid nodules with oncocytic cytology. SUBJECTS AND METHODS: Twenty-four patients with a single (or prevalent) 'cold' solid nodule with Hurthle cells (HC) at fine needle aspiration cytology (FNAC) were studied. Cytological diagnosis of oncocytic metaplasia (OM) or HC tumor (HCT) was made when HC on the smear were comprised 10-75%, or >75%. Nodules concentrating MIBI at early and late (2 h after washout) stages were considered MIBI-positive. In all cases histological findings were obtained after total thyroidectomy. RESULTS: FNAC was malignant or suspect for malignancy in 16 cases (six HCT and 10 OM) and not suspect in eight (two HCT and six OM). Histological examination revealed 14 malignant tumors (11 HCT and three OM), and 10 benign thyroid lesions (three HCT and seven OM). Sensitivity of FNAC for malignancy was 92.8% and specificity was 70.0%; HCT were identified by FNAC in only 35.7% and OM in 70.0% of cases. No significant difference in MIBI positivity was found between malignant and benign thyroid nodules. The highest percentage of MIBI positivity was found in HCT (78.5%), but MIBI-positive nodules were also observed in thyroid lesions with HC metaplasia (40.0%). CONCLUSIONS: MIBI scintiscan has no value in differentiating malignant from benign HC thyroid neoplasias. Most HCT are MIBI-positive, but this scan is not sufficiently specific to differentiate true HC neoplasias from other thyroid lesions showing HC at FNAC, although an MIBI-negative scan strongly supports the absence of true HCT.

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Abstract: Recently, concentrations of serum carboxy-terminal-1-telopeptide (ICTP), a marker of bone collagen resorption, were found to be more sensitive than sex hormone-binding globulin (SHBG) in identifying peripheral overexposure to thyroid hormones in exogenous subclinical hyperthyroidism. The aim of the present study was to assess serum ICTP and SHBG in multinodular goiter with (pretoxic goiter) or without biochemical evidence of endogenous subclinical hyperthyroidism. Forty-five women affected by multinodular goiter were enrolled in this study. They were subdivided into two groups: group 1, consisting of 27 patients affected by pretoxic goiter; group 2, consisting of 18 patients affected by non toxic goiter; group 3, consisting of thirty-six euthyroid women matched with the other groups for age and lifestyle. In group 1, serum ICTP (mean +/- SD: 5.8 +/- 2.9 microg/l) concentrations were significantly higher when compared either to group 2 (3.6 +/- 1.2 microg/l; p < 0.02) or controls (2.7 +/- 0.7 microg/l; p < 0.0001); serum ICTP concentrations were also slightly but significantly higher in patients of group 2 compared to controls (p < 0.003). In contrast, mean serum SHBG concentrations did not show any difference among the three groups. No significant correlation was found between serum TSH and ICTP concentrations, while a weak positive correlation (p < 0.05) was only found between serum FT 3 and ICTP concentrations when data from the two patient groups were analyzed together. Moreover, when we subdivided patients into pre- and postmenopausal patients, we observed that SHBG but not ICTP serum concentrations were influenced by estrogenic status. In summary, the measurement of serum ICTP seems to be more suitable than SHBG for identifying those with a higher degree of peripheral thyroid hormone exposure in women affected by endogenous subclinical hyperthyroidism.

Abstract: Acromegaly is frequently associated with the presence of thyroid disorders, however the exact prevalence is still controversial. An Italian multicenter study was performed on 258 patients with active acromegaly (high levels of IGF-I and lack of suppression of serum GH levels below 2 microg/l after an OGTT). The control group was represented by 150 patients affected by non-functioning and PRL-secreting pituitary adenomas. Two hundred and two out of 258 acromegalic patients (78%) were affected by thyroid disorders with a significantly higher prevalence with respect to the control group (27%, p<0.0001). One hundred and three patients presented (39.9%) non-toxic nodular goiter, 46 (17.8%) non-toxic diffuse goiter, 37 (14.3%) toxic nodular goiter, 1 toxic diffuse goiter (0.4%), 12 (4.6%) Hashimoto's thyroiditis, 3 (1.2%) thyroid cancer. Two patients presented a co-secreting TSH pituitary adenoma. Thirty-six patients had been previously treated for various thyroid abnormalities. Among the 222 acromegalic patients never treated for thyroid disorders thyroid ultrasonography was performed on 194 subjects. Thyroid volume in patients with thyroid abnormalities was 28+/-17.5 ml (median 23) while it was 10.8+/-3.6 ml (median 10) in patients without thyroid disorders (p<0.0001). Thyroid volume was correlated with the estimated duration of acromegaly (r=0.7, p<000.1), but not with age or with serum GH, IGF-I and TSH concentrations. Thyroid volume was higher in acromegalic patients than in the above control population (23.5+/-16.9 ml vs 13.9+/-12.8 ml, p<0.0001). In 62 acromegalic patients 101 fine-needle biopsies of thyroid nodules were performed; 7 nodules were suspicious and the patients were submitted to thyroid surgery: papillary thyroid carcinoma was found in 3 patients. In conclusion, in a large series of acromegalic patients an increased prevalence of thyroid disorders (78%), particularly non-toxic nodular goiter, has been observed. Thyroid volume, evaluated by ultrasonography, was correlated to the estimated duration of acromegaly. Finally, the prevalence of thyroid carcinoma was slightly increased than in the general population.

Abstract: Acquired hemophilia due to autoantibody to Factor VIII coagulant (Factor VIIIc) is a rare event which may be observed in patients with different autoimmune diseases. To our knowledge, this association has been reported only once in patients with autoimmune thyroid disease. Here we describe a patient presenting with a severe hemorrhagic disorder due to Factor VIIIc antibody in whom biochemical screening for thyroid diseases led to a diagnosis of hyperthyroid Graves' disease not associated to overt clinical features. This case underlines the importance of carrying out a complete screening for autoimmunity, including thyroid autoimmune disease, in all patients with apparently isolated serum Factor VIIIc inhibitors.

Abstract: We investigated a 48-yr-old woman on L-T4 therapy (100 microg/d) for primary autoimmune hypothyroidism, diagnosed 15 yr earlier, presenting a firm oval lump in the right thyroid lobe and symptoms of mild thyrotoxicosis. Free T4, free T3, TSH, anti-thyroperoxidase, anti-TG and anti-thyroid microsomal antibodies were determined. Thyroid US and color flow Doppler sonography (CFDS), 99mTechnetium (99mTc), radioiodine scintiscan and US guided fine needle aspiration cytology (FNAC) were performed. On L-T4 therapy, thyroid function tests showed subclinical hyperthyroidism with high anti-thyroid antibody titers. Thyroid US and CFDS revealed a voluminous hypoechoic hypervascularized nodule with increased peak systolic velocity (type III pattern) in the right lobe; the extranodular tissue volume was markedly reduced and hypoechoic. The presence of an autonomous functioning nodule associated to Hashimoto's thyroiditis (HT) was suspected, L-T4 therapy was temporary withdrawn, and the patient re-evaluated 2 months later. Off L-T4 therapy, thyroid function tests revealed marked primary hypothyroidism, while thyroid US and CFDS were unchanged. 99mTc thyroid scan showed a focal increased uptake corresponding to the nodule in the right lobe with nearly absent uptake in the remaining thyroid tissue. Only a faint, patchy thyroid distribution of 131I was detected by radioiodine scan, and RAIU was very low. Cytological examination by FNAC revealed normal follicular cells and several lymphocytes. The final diagnosis was therefore hypothyroid HT with pseudo-nodular thyroid tissue of the right lobe. To our knowledge, this is the first report of HT mimicking both scintigraphic and CFDS features of an autonomous functioning nodule.

Abstract: OBJECTIVE: To evaluate the association between celiac disease and specific anxiety and depressive disorders and to identify potential common pathogenetic links, with particular regard to thyroid function and autoimmunity. METHODS: Cases included 36 adult celiac patients, 25 females and 11 males, aged 18-64 years. Controls comprised 144 healthy subjects matched by sex and age with no clinical evidence or family history of celiac disease. Diagnosis of celiac disease was made on the basis of clinical history and serological criteria. Psychiatric diagnoses were formulated using the International Composite Diagnostic Interview, according to DSM-IV criteria. Thyroid was evaluated by palpation, echography and measurement of serum-free thyroid hormones (FT4, FT3), thyroid-stimulating hormone (TSH) and antithyroid autoantibodies (anti-TPO). RESULTS: Compared to controls, a significantly higher number of celiac patients met criteria for lifetime [15 (41.7%) versus 30 (29.8%), P < .01] and 6-month [7 (19.4%) versus 9 (6.2%), OR = 3.2, chi(2) = 5.2, P < .05] major depressive disorder (MDD) and lifetime [5 (13.9%) versus 3 (2.1%), P < .001] and 6-month [3 (8.1%) versus 2 (1.4%), P < .05] panic disorder (PD). Anti-TPO prevalence was significantly higher in celiac patients than in the control group (11/36 = 30.5% versus 14/144 = 9.7%, P < .001). A higher frequency of PD and MDD was found in celiac patients with positive anti-TPO when compared to negative anti-TPO patients (4/11 = 36.4% PD in TPO+ versus 1/25 = 4% PD in TPO-, P < .01; 9/11 = 81.8% MD in TPO+ versus 6/25 = 9.5% MD in TPO-, P < .01). CONCLUSION: Patients affected by celiac disease tend to show a high prevalence of PD and MDD and association with subclinical thyroid disease appears to represent a significant risk factor for these psychiatric disorders.

Abstract: The relationship among iodine intake, goiter prevalence, and thyroid autoimmunity remains controversial. In the present article, we report the prevalence of antithyroid antibodies (ATA) in relation to iodine intake, frequency of goiter, and thyroid function in a large group of Sardinian schoolchildren living in areas with borderline iodine sufficiency, or mild to moderate iodine deficiency. A total of 8,040 schoolchildren (4,194 males, 3,846 females, ages 6-15 years) from 29 communities were examined between 1986-1994. Thyroid size was assessed by palpation, according to the Pan American Health Organization (PAHO) criteria. In all cases antimicrosomal (MAb) or antithyroid peroxidase antibodies (TPOAb) and thyrotropin (TSH) were assayed. Urinary iodine was determined in a subgroup of 820 children. ATA was detected in 235 (2.92%) sera (88 males, 2.12%; 147 females, 3.82%; chi2 = 20.41, p < 0.0001). ATA prevalence ranged between 0.0%-7.3% in the 29 communities without any geographical correlation with goiter prevalence and urinary iodine excretion. However, ATA was more frequently detected in goitrous children, especially in females. The presence of ATA was not age-dependent in males, whereas a significant increase of ATA was observed in females older than 11 years of age. Seventy-seven (0.96%) children showed borderline to slightly increased serum TSH (>5.2-32 mU/L). Increased serum TSH concentration was more frequently found in children with ATA, especially at higher titers. In summary, our study in Sardinian schoolchildren indicates: (1) ATA display geographical heterogeneity, which seems to be unrelated to goiter prevalence and/or to iodine supply; (2) ATA are more frequently detected in females older than 11 years of age, suggesting that puberty has a role in determining the predominance in females of thyroid autoimmunity; (3) although most goitrous children are ATA-negative, the prevalence of ATA is increased in children with enlarged glands; (4) ATA is associated with an increased prevalence of subclinical hypothyroidism.

Abstract: The objective of this paper was to study prospectively the course of clinically relevant thyroid dysfunction in a cohort of patients on long-term lithium treatment. Patients (N = 150) who had undergone a cross-sectional evaluation of their thyroid function in 1989, when they were at different stages of lithium treatment, were followed up for the presence of thyroid autoimmunity, hypothyroidism, and goiter during a further period of lithium exposure of up to ten years. The following annual rates of newly developed thyroid dysfunction were observed: autoimmunnity (1.4%), subclinical hypothyroidism (1.7%), and goiter (2.1%). Subjects with thyroid autoimmunity had a higher chance of requiring substitution treatment with levothyroxine for subclinical hypothyroidism compared with subjects with no evidence of thyroid autoimmunity (13/32 = 41% versus 7/118 = 6%). Subjects (N = 15) who were prescribed carbamazepine in addition to lithium showed a significant decrease of TSH concentrations. In patients already being treated with lithium for several years, the overall incidence of hypothyroidism, goiter, and thyroid autoimmunity were comparable with those reported for the general population. However, lithium exposure may represent an additional risk factor for hypothyroidism in women and/or in the presence of thyroid autoimmunity.

Abstract: A high incidence of autoimmune Type 1 diabetes mellitus (DM) has been clearly established in Sardinia. Although systematic epidemiological studies are still not available, an increased prevalence of thyroid autoantibodies (ATA) has been documented in the Sardinian adult population as compared to other Italian regions, suggesting that thyroid autoimmune disease may also have increased. We carried out a preliminary study with the aim of determining the prevalence of serological markers of thyroid (anti-thyroperoxydase antibodies, TPOAb) and islet cell (ICA) autoimmunity in a large number (no.=2249) of sera obtained from cord-blood of Sardinian pregnant women at delivery. The prevalence of TPOAb was 11.9%, while ICA were detected in 59 cases (2.6%). A higher prevalence of TPOAb (6/17=35.3%) was found in sera with high ICA titers (> or = 20 JDF-U), as compared to sera with low ICA titers (5-19 JDF-U) and to ICA-negative sera (3/42=7,1%; chi2=5.4, p=0.02 and 258/2190=11,8%; chi2=6.8, p=0.009 respectively). Fourteen women (all ICA-negative) were diabetic: 4 had Type 1 and 10 had gestational DM; due to the low number, no correlation could be established between DM type and TPOAb prevalence and/or titer. These preliminary data indicate that ATA are frequently observed in the general population of Sardinian pregnant women at term. As a consequence, even the frequency of postpartum thyroiditis is expected to be high. Although ATA were not increased in women with clinical overt diabetes, a higher prevalence of ATA was found in women with high titers of circulating ICA. Our results also confirm that Sardinia represents, perhaps for its peculiar genetic characteristics, an ideal place to study organ-specific autoimmunity.

Abstract: As recently claimed, TSH-suppressive therapy with L-T4 may have adverse effects on the heart, but these results have not been consistently confirmed. We assessed cardiac function by clinical, echocardiographic, and ergometabolic criteria in 19 patients (16 women and 3 men) receiving long term L-T4 at a fixed daily dose ranging from 1.8-4.0 microg/kg. The results showed significant alterations in several cardiac parameters suggestive of subclinical hyperthyroidism. In particular, intraventricular septum thickness (10.0+/-1.4 vs. 8.1+/-1.1 mm), left ventricular posterior wall thickness (9.4 1.5 vs. 8.1+/-1.1 mm), end-diastolic dimension (47+/-4 vs. 44+/-3 mm), and left ventricular mass index (102+/-15 vs. 75+/-15 g/m2) were significantly increased compared to values in age- and sex-matched euthyroid controls. Exercise tolerance (expressed as maximal tolerated workload; 102+/-14 vs. 117+/-12 watts), maximal VO2 achieved at peak exercise (maximum VO2, 17.3+/-3.3 vs. 21.9+/-2.5 mL/min x kg), and anaerobic threshold (expressed as a percentage of VO2max, 46.5+/-8.4 vs. 56.2+/-6.6) were significantly reduced in L-T4-treated patients. The L-T4 dose was then reduced to the minimal amount able to keep the serum TSH concentration at 0.1 mU/L or less in 7 patients who were reevaluated 6 months after the initial study. This individual tailoring of the TSH-suppressive L-T4 dose was in all cases associated with normalization of all echocardiographic and ergometabolic parameters. In conclusion, our findings show that abnormalities of heart morphology associated with impaired exercise performance occur as a consequence of long term therapy with fixed TSH-suppressive doses of L-T4, but that these abnormalities improve or disappear after careful tailoring of TSH-suppressive therapy.

Abstract: OBJECTIVE: To assess the potential role of conventional sonography and colour flow Doppler (CFD) sonography (CFDS) in the differential diagnosis of toxic multinodular goitres. SUBJECTS AND METHODS: We investigated 55 patients with untreated hyperthyroidism (24 with typical toxic diffuse goitre of Graves' disease (Group A); 26 with multinodular goitre (Group B); and five with single toxic adenoma (Group C); 22 euthyroid subjects (12 with non-toxic multinodular goitre (Group D) and ten normal subjects (Group E)) were included as controls. In all cases free thyroxine, free tri-iodothyronine, TSH, TSH receptor antibodies (TRAb), anti-thyroperoxidase antibody, anti-thyroglobulin antibodies and anti-thyroid microsomal antibodies were determined and a [(99m)Tc]pertechnetate thyroid scan was performed. RESULTS: Patients with toxic multinodular goitre displayed two different CFDS patterns: 18 patients (Group B-1) had nodules with normal vascularity surrounded by diffuse parenchymal hypoechogenicity with markedly increased CFD signal and maximal peak systolic velocity (PSV) (a pattern similar to Group A patients with Graves' disease); eight patients (Group B-2) had increased intra- and perinodular CFD signal and PSV with normal extranodular vascularity (a pattern similar to that found in Group C patients with single toxic adenoma). Patients of Group B-1 showed a proportion of clinically evident thyroid ophthalmopathy, positive TRAb and other thyroid autoantibodies similar to that observed in Group A patients, while no evidence of thyroid autoimmunity was found in Group B-2. Sixteen out of 18 (89%) patients from Group B-1 displayed a scintiscan pattern of diffuse uneven radionuclide distribution, while seven out of eight (87.5%) of those from Group B-2 had localized uptake in multiple discrete nodules. Taken together, these data strongly suggest that Group B-1 mostly represents patients with the multinodular variant of Graves' disease, while Group B-2 represents patients with non-autoimmune toxic multinodular goitre. CONCLUSIONS: This study shows that combined conventional sonography and CFDS may easily distinguish nodular variants of Graves' disease from non-autoimmune forms of toxic multinodular goitre and confirms the clinical usefulness of this technique in the first-line evaluation of hyperthyroid patients.

Abstract: We previously showed that myasthenia gravis (MG) has a mild clinical expression when associated with autoimmune thyroid diseases (AITD). In the present study we have investigated the frequency of thyroid-associated ophthalmopathy (TAO) in patients with Graves' disease (GD) associated with MG as compared with GD patients without MG. A total of 418 patients with GD were studied, 31 with MG and 387 without MG. TAO was evaluated by physical examination, exophthalmometry, computerized tomography, and computerized visual fields assessment. The overall prevalence of TAO was similar in GD patients with MG (61.2%) and in those without MG (56.4%). When the analysis was restricted to GD patients with ocular MG, a greater frequency of TAO was found (84.6%), compared with GD patients without MG or with GD patients with generalized MG, although the differences did not reach the statistical significance. GD patients with MG had a significantly greater prevalence (12.9%) of euthyroid ophthalmopathy (clinically overt ophthalmopathy without previous and/or current hyperthyroidism) than those without MG (3.1%; p = 0.003). The results suggest a preferential association between the ocular manifestations of GD and MG, which may be due to immunological cross-reactivity against common autoimmune targets in the eye muscle as well as to a common genetic background.

Abstract: OBJECTIVE: To verify whether the accuracy of data on myocardial function provided by pulsed-wave tissue Doppler imaging (PWTDI), a new echocardiographic application that allows quantitative measurements of myocardial wall velocities, could help towards a better understanding of the natural history of acromegalic cardiomyopathy. DESIGN: Eighteen patients with active acromegaly (ten men and eight women; mean age 48.0+/-15.0 years) with no other detectable cause of heart disease underwent PWTDI. Thirteen healthy individuals matched for age and body mass index acted as a control group. METHODS: Ejection fraction (EF), transmitral early/late diastolic velocity (E/A) ratio and isovolumic relaxation time (IVRT) were measured by conventional echocardiography; systolic peak (Sv) and early (Ev) and late (Av) diastolic peak velocities, Ev/Av ratio and regional IVRT (IVRTs) were obtained by PWTDI. RESULTS: All patients showed appreciably abnormal left ventricular global diastolic function represented by prolongation of the IVRT (P<0.001). Using PWTDI we found a prolongation of IVRTs and inversion of the Ev/Av ratio. In addition, the Ev/Av ratio proved to be significantly negatively correlated with IVRT; this correlation was not present in the case of the E/A ratio. Furthermore, a decrease in Sv was detected in the basal segment of the lateral wall (P<0.01), which had the greatest degree of diastolic dysfunction. CONCLUSIONS: PWTDI confirmed the acknowledged diastolic dysfunction that accompanies acromegalic cardiomyopathy and highlighted the greater sensitivity of regional PWTDI with respect to global Doppler diastolic indexes. Furthermore, by revealing an impairment of regional systolic function in presence of a normal EF, the findings with PWTDI contradicted the largely accepted theory that systolic function remains normal for several years in patients affected by acromegalic cardiomyopathy.

Abstract: Amiodarone may induce hyper- or hypothyroidism. Patients with beta-Thalassemia Major (beta-Thal) have an increased prevalence of primary hypothyroidism and often require amiodarone for hemosyderotic cardiomyopathy. Aim of this study was to retrospectively evaluate thyroid function in beta-Thal adult patients on long-term amiodarone. The study group consisted of twenty-two (21 males, 1 female; age: 23-36 yr) beta-Thal patients submitted to long-term (3-48 months) amiodarone therapy from January 1991 to July 1996. Controls included 73 beta-Thal patients (23 males and 50 females aged 25-35 yr) not treated with amiodarone. In all cases serum free thyroid hormones, thyrotropin and thyroid autoantibodies were evaluated. A higher prevalence of overt hypothyroidism (5/22 [22.7%]) as compared to controls (3/73 [4.1%], p=0.02) was found in beta-Thal patients < or = 3 months after starting amiodarone, while the prevalence of subclinical hypothyroidism was similar in amiodarone-treated (18.2%) and untreated (15%) beta-Thal patients. Overt hypothyroidism resolved spontaneously after amiodarone withdrawal in 1 case, while the remaining patients were maintained euthyroid on amiodarone by L-thyroxine administration. After 21-47 months of amiodarone therapy, 3 patients (13.6%) developed thyrotoxicosis (2 overt and 1 subclinical), which remitted shortly after amiodarone withdrawal. No case of hyperthyroidism was observed in beta-Thal controls (p=0.012 vs amiodarone-treated patients). In conclusion, amiodarone administration is often associated in adult beta-Thal patients to a rapid progression of the pre-existing subclinical hypothyroidism, but transient thyrotoxicosis may also be observed after a longer period of therapy. These findings should be carefully considered in the management of these patients.

Abstract: BACKGROUND: Thymectomy (Tx) is a common therapeutic option to treat myasthenia gravis (MG), but its effects on the immune system are still obscure in humans. OBJECTIVE: We sought to evaluate long-term immunologic effects of therapeutic Tx in patients with MG. METHODS: T- and B-cell subsets and T-cell repertoire were analyzed in 35 patients with MG, 16 with previous Tx (at least 8 years before), 6 with recent (<1 year) Tx, and 13 without Tx, as well as in 32 healthy subjects used as normal control subjects. Serum immunoglobulins and a variety of autoantibodies were also measured. A subsequent 3-year clinical follow-up was performed to verify the possible appearance of systemic autoimmune diseases. RESULTS: The long-term thymectomized (Txd) patients had mild T-cell lymphopenia and an expansion of some Vbeta families among circulating CD4+ and CD8+ T cells. They displayed a normal number of total B and CD5+ B-circulating lymphocytes, but they also displayed a polyclonal increase in serum IgM and IgG associated with the presence of high levels of a variety of organ- and nonorgan-specific autoantibodies, including anti-dsDNA and anticardiolipin, without clinical evidence of autoimmune disease. These serologic abnormalities were not detectable in both non-Txd and recently Txd patients. After 3 years, 2 long-term Txd patients had systemic lupus erythematosus and an undifferentiated connective tissue disease. CONCLUSIONS: The association between MG and laboratory findings of systemic autoimmune disease may be in part related to Tx rather than to MG. Tx may represent a risk for the development of systemic autoimmune disorders over years in patients with MG.

Abstract: This paper describes an epidemiological study performed in all centenarians living in Sardinia, a large island located in the Mediterranean sea, 120 Km from the Italian coast. Due to its long-standing isolation, low immigration rate, high endogamy and rather uniform lifestyle, Sardinia offers an ideal setting in which to study the genetic traits associated with extreme longevity and successful aging. A total of 233 potentially eligible centenarians were traced in the entire territory. Of these, 66 died prior to being interviewed, 11 were not found and unknown, and 15 refused to be interviewed. A multidimensional home interview was administered to 141 centenarians, and an equivalent number of 60-year-old controls matched for gender and area of residence. Furthermore, 41 living siblings of the centenarians, and 41 age- and sex-matched controls for these siblings were also studied. The prevalence of centenarians was 13.56 per 100,000, and the female/male ratio was approximately 2. Prevalence and female/male ratio were consistent across the four Sardinian municipalities and are, respectively, higher and lower than those reported in other population-based surveys. A number of methodological problems confronted in doing the field work, and plans for future analysis of this rich dataset are discussed.

Abstract: To assess the relationship between serological markers of thyroid autoimmunity and chronic hepatitis C, we surveyed the general population of two villages in the region of Sardinia, Italy, where infection with hepatitis viruses is endemic and the prevalence of autoimmune diseases is elevated. A total of 1310 subjects aged 6-88 years (65% of the total resident population) participated in the survey, and 1233 (94%; 444 males and 789 females) agreed to provide a blood sample. Autoantibodies to thyroid peroxidase (anti-TPO) were measured by radioimmunoassay; antibodies to HCV (anti-HCV) by a third generation enzyme immunoassay and borderline positive results confirmed by recombinant immunoblot assay. For both anti-HCV and anti-TPO the age- and gender-standardized prevalence rates (SPR) were calculated and the significance of the association between the two antibodies tested by Yates corrected chi2 test. The overall SPR for anti-HCV was 50.7x10(-3) (86/1,233), similar between men [49.1x10(-3) (22/444)] and women [52.3x10(-3) (64/789)]. The overall SPR for anti-TPO was 136.9x10(-3) (204/1,233), and that among women [201x10(-3) (174/789)] was almost 3-fold that among men [71.6x10(-3) (30/444)]. A concurrent anti-HCV and anti-TPO positivity was found in a small minority of subjects [8/1,233 (0.65%)], all women aged 57-81 years. The SPR for the two concurrent events was 3.3x10(-3), which was not significantly different (Yates corrected chi2 test = 0.65) from that expected under the assumption of unrelated events. To explore whether HCV infection is a risk factor for anti-TPO positivity, we designed a case-control study with anti-TPO positive subjects as the cases, and anti-TPO negative subjects as the controls. The age- and gender-adjusted odd ratio (OR) was 0.4 (95% CI 0.2,0.7), indicating a negative association. In conclusion, no evidence for epidemiological association of circulating thyroid autoantibodies and antibodies to HCV was found. Our findings do not therefore support a pathogenetic link between HCV infection and thyroid autoimmunity.

Abstract: Circulating thyroid autoantibodies were assessed in a sample of Italian octo-nonagenarians living in a restricted area (Val Vibrata, Abruzzo), and selected according to the absence or presence of chronic illness and disability. The study groups included: Group A ("Successful aging"), 98 free-living healthy, fully independent, octo-nonagenarians (57 males and 41 females, average age +/-SD 83.9+/-3 years); Group B ("Unsuccessful aging"), 62 highly disabled octo-nonagenarians (24 males and 38 females; average age 86.5+/-3.4 years), and Group C (Controls), 91 randomly selected healthy adult controls (42 males and 49 females; age 53.7+/-16.6 SD years, range 20-70). Serum autoantibodies to thyroglobulin (anti-Tg) and to thyroid peroxidase (anti-TPO) were measured by passive hemagglutination and radioimmunoassays (RIA); serum free thyroxine and thyrotropin by RIA. The prevalence of positive thyroid autoantibody tests was not significantly increased in the elderly groups compared to the controls, with the remarkable exception of anti-Tg detected by RIA which were increased in disabled elderly, compared to free-living elderly and controls. Two/62 disabled elderly had subclinical (1) or mild (1) primary hypothyroidism, and one free-living woman aged 90 years was hyperthyroid (toxic nodular goiter). No correlation was found between serum thyroid autoantibodies, thyroid hormones and TSH and serum lipoprotein fractions. The higher prevalence of thyroid autoantibodies found only in disabled, but not in free-living Italian octo-nonagenarians suggests that thyroid autoimmune phenomena in the elderly may be an expression of age-associated disease rather than related to the aging process in itself.

Abstract: A 68-yr-old woman presented to our observation with multinodular goiter and a contiguous right laterocervical mass. In spite of ultrasound, technetium and iodine scan, CT and fine-needle biopsy, the precise origin of the mass remained uncertain. On additional multi-phase sestamibi scan, the neck region showed an early high uptake rapidly decreasing over time in the laterocervical mass, and a persistent inhomogeneous distribution in the thyroid gland. This behavior suggested that the laterocervical mass could derive from an anatomical structure other than the thyroid. Surgical exploration established the extrathyroid nature of the laterocervical mass and the histological examination confirmed that it was a typical paraganglioma. This finding is in keeping with a recent report of positive sestamibi uptake in a cervical paraganglioma, although our case showed a more rapid kinetic. This tumor should be therefore taken into consideration in the differential interpretation of focal sestamibi uptake.

Abstract: OBJECTIVE: We sought to reevaluate the prevalence of thyroid dysfunction and thyroid autoimmunity in 47 patients with celiac disease; 91 healthy subjects were studied as controls. Both patients and controls were from Sardinia, Italy. METHODS: Diagnosis of celiac disease was made on the basis of clinical history, presence of positive antigliadin IgA (AGA-A) and IgG (AGA-G) antibodies, antireticulin antibodies (ARA), antiendomysium antibodies (EMA), and was confirmed by jejunal biopsy. HLA class II typing for DQB1 and DQA1 alleles was performed in 36/47 celiac patients. Thyroid was evaluated by palpation and echography; serum free thyroid hormones (FT4, FT3), thyrotropic hormone (TSH), and antithyroid peroxidase autoantibodies (anti-TPO) were assayed by radioimmunoassays. RESULTS: The prevalence of anti-TPO was higher in celiac patients (29.7%) than in healthy controls (9.6%) (p < 0.001) and thyroid echography frequently displayed (42.5%) a hypoechogenic pattern. Five anti-TPO-positive celiac patients were hypothyroid (two overt, three subclinical). A higher but not significantly different prevalence of anti-TPO (3/7 = 42.8%) was found in celiac patients displaying the DQB1*0502 genotype, when compared with the remaining patients (8/29 = 27.6%). CONCLUSIONS: An elevated prevalence of clinical and subclinical autoimmune thyroid autoimmunity was found in Sardinian celiac patients, especially in those displaying the DQB1*0502 genotype; this finding could be related to a particular genetic background of the Sardinian population.

Abstract: Aging is associated with the appearance of several serum autoantibodies, including thyroid autoantibodies. The biological and clinical significance of this phenomenon is still unknown, because, with the exception of primary myxedema, the prevalence of clinically overt thyroid autoimmune diseases is not increased in the elderly. The peculiar link between autoimmune thyroid failure and aging is also underscored by the high prevalence of subclinical hypothyroidism in elderly subjects with positive serum thyroid autoantibodies, and could be the consequence of preferential age-dependent expression of destructive effector mechanisms and/or increased target gland susceptibility. Thyroid autoimmunity and subclinical hypothyroidism have been also implicated in the pathogenesis of other age-associated disorders, in particular coronary heart disease. Interestingly, recent data from our laboratories showed that thyroid autoantibodies are rare in healthy centenarians and in other highly selected aged populations, while they are frequently observed in unselected or hospitalized elderly. Taken together, these data suggest that thyroid autoimmune phenomena are not the consequence of the aging process itself, but rather might be related to age-associated disease.

Abstract: Sardinia and Finland have the highest incidence of insulin-dependent diabetes mellitus (IDDM) in the world. Therefore, both regions represent ideal observatories for investigating the environmental, genetic and immunological factors which have led to this dramatic increase. We have concentrated our efforts on Sardinia. Among several projects, there is the mapping of the island for hot and cold spots for overt IDDM. In order to map the island for pre-IDDM, we have collected and bled around 10,000 school children (age 6-14 years) and we are now in the process of enrolling around 30,000 new-born babies. We report here our initial results, which show that progression to IDDM is accompanied in both cohorts by the presence of a combination of islet-cell antibodies with either glutamic acid decarboxylase or IA-2 antibodies or both. This approach should lead to the design of reliable models of IDDM prediction in the general population, which will benefit an early insulin treatment and, hopefully, an effective prevention of the disease.

Abstract: Sardinia and Finland have the highest incidence of IDDM in the world. Thus, both regions represent ideal observatories for investigating the environmental, genetic and immunological factors, which have led to this dramatic increase. We have concentrated our efforts in Sardinia. Among several projects, there is the mapping of the Island for hot and cold spots for overt IDDM. In order to map the Island for pre-IDDM, we have collected and bled around 10,000 school children (age 6-14 years) and we are now in the process to enroll around 30,000 newborn. We report here our initial results, which show that progression to IDDM is accompanied in both cohorts by the presence of a combination of ICA with either GAD and IA-2 antibodies or both. This approach should lead to design reliable models of IDDM prediction in the general population, which will benefit an early insulin treatment and, hopefully, an effective prevention of the disease.

Abstract: Psychiatric patients on long-term lithium (Li) therapy frequently develop goiter and/or hypothyroidism. It has also been suggested that Li may trigger/exacerbate thyroid autoimmunity. Previous studies provided evidence that underlying thyroid diseases represent important predisposing factors for the development of Li-induced thyroid dysfunction. The aim of the present paper was to assess the value of thyroid ultrasound-a simple and reliable tool to detect subtle thyroid abnormalities-in the longitudinal evaluation of 23 Li-treated psychiatric patients without evidence of biochemical thyroid abnormalities before therapy. For this purpose, thyroid ultrasound was associated with a clinical and laboratory (serum thyroxine, serum triiodothyronine, serum TSH, antithyroglobulin (AbTg), antithyroid microsomal (AbM) and antithyroid peroxidase autoantibodies) evaluation prior to and at 6- to 12-month intervals during Li treatment. On the basis of thyroid ultrasound before Li, patients were subdivided into two groups: group A (n = 15, 7 males, 8 females) with a normal echography and group B (n = 8, 5 males, 3 females) with mild ultrasound abnormalities. In group A the development of a small diffuse goiter was confirmed by physical examination during Li therapy; 2 patients displayed a transient increase of serum TSH concentration and none developed detectable serum antithyroid autoantibodies. Beside the small volumetric increase, no other ultrasound abnormalities were observed during the entire follow-up. In all group B patients a mild diffuse goiter was clinically detected before and on Li administration and no significant volumetric changes were observed during follow-up. Two patients developed high titers of AbM and AbTg 12 and 18 months after the beginning of Li, respectively; in 1 a persistent increase of serum TSH concentration was also observed. Thyroid echography before Li displayed different degrees of scattered or diffuse hypoechogenicity and a further decrease in echogenicity was detected during Li therapy in 2 patients. In conclusion, we provided further evidence that long-term Li administration is not associated with de novo appearance of thyroid autoimmune phenomena in humans, but rather with an exacerbation of underlying thyroid autoimmunity. In addition to thyroid autoantibody and TSH measurements, thyroid echography appears to be a sensitive tool in the identification of patients at risk of developing autoimmune hypothyroidism during long-term Li therapy.

Abstract: The ageing thyroid is associated with a number of morphological and functional changes, such as decreased serum T3 and mean thyroid-stimulating hormone concentrations, that are to some extent independent of intercurrent non-thyroidal illnesses. All thyroid diseases, including clinical and subclinical hypo- and hyperthyroidism, non-toxic nodular goitre and thyroid cancer, are encountered in the elderly, but their prevalence and clinical expression differ from those observed in younger patients. In the elderly, autoimmune hypothyroidism is particularly prevalent, hyperthyroidism is mainly characterized by cardiovascular symptoms and is frequently due to toxic nodular goitres, and differentiated thyroid carcinoma is more aggressive. The interpretation of thyroid function tests is difficult in old individuals, because of age-associated changes in thyroid function and frequent alterations secondary to non-thyroidal illnesses and/or drugs. Treatment of thyroid disease deserves special attention in old patients because of the increased risk of complications.

Abstract: The aim of the present investigation was to evaluate the clinical performance of serum carboxy-terminal-1-telopeptide (ICTP), a new marker of bone resorption, in identifying peripheral overexposure to thyroid hormones, as compared with serum osteocalcin (OC) and serum sex hormone binding globulin (SHBG). Serum ICTP, SHBG, and OC were assayed by specific radioassays in three study groups. Group 1: 50 perimenopausal women on long-term levothyroxine (LT4) suppressive treatment; group 2: 29 women with untreated hyperthyroidism; group 3: 36 normal euthyroid women matched with group 1 patients for age, alcohol, smoking habits, and lifestyle. Serum concentrations of SHBG, ICTP, and OC were markedly increased in hyperthyroid patients, whereas only serum ICTP was slightly but significantly increased in LT4 treated patients. Serum ICTP had higher diagnostic value for hyperthyroidism when compared with SHBG and to OC (sensitivity: 100%, 71%, 55%; accuracy: 97%, 88%, and 76%, respectively). In group 1, increased serum ICTP was observed in 30 of 50 patients, whereas increased SHBG and OC were found only in 11 of 50 (p < .001). Serum free thyroid hormone concentrations correlated with circulating ICTP and SHBG, and the correlation with serum OC was of lower significance. In conclusion, serum ICTP is a sensitive and reliable marker of peripheral thyroid hormone activity at the bone level; its clinical performance is higher than OC and even better than SHBG. Thus, serum ICTP is better than other peripheral markers in monitoring LT4 suppressive therapy in patients at increased risk for osteoporosis such as perimenopausal women.

Abstract: Myasthenia gravis (MG) may occur in association with autoimmune thyroid diseases (AITD). The aim of this study was to evaluate the features of MG associated with AITD compared to those of MG without AITD. A total of 129 MG patients (34 men and 95 women; age range, 11-81 yr) were subdivided into: group A, 56 MG patients with AITD [25 with autoimmune thyroiditis and 31 with Graves' disease (GD)]; group B, 21 MG patients with nonautoimmune thyroid diseases; and group C, 52 MG patients without thyroid disease. The severity of MG was ranked according to the Osserman score. Laboratory evaluation included assays for antithyroid and antiacetylcholine receptor (AchRAb) antibodies. Ocular MG (Osserman's class 1) was more frequent in group A (41.0%) than in group B (14.2%; P < 0.03) or C (21.4%; P < 0.03). Severe generalized MG (classes > or = 2B) was more frequent in groups B (57.1%; P < 0.03) and C (51.9%; P < 0.02) than in group A (28.5%). GD patients with clinical evidence of ophthalmopathy had a higher frequency (P = 0.05) of ocular MG (57.8%) than GD patients without clinical ophthalmopathy (16.6%). Thymic disease was less frequent in group A (26.7%) than in group B (71.4%; P = 0.001) or C (59.7%; P = 0.001). The prevalence of thymic hyperplasia was 17.8%, 38.0%, and 40.3% in groups A, B, and C, respectively; the prevalence of thymoma was 8.9%, 33.4%, and 19.4%. When only patients with generalized MG were considered, thymic disease was less frequent (P < 0.02) in group A (40.6%) than in the remaining groups (69.4%). AchRAb was more frequent in groups B (57.1%) and C (57.6%; P < 0.03) than in group A (35.7%). In conclusion, MG associated with AITD has a mild clinical expression, with preferential ocular involvement and lower frequency of thymic disease and AchRAb. This supports the hypothesis that ocular and generalized MG are separate diseases with different spectra of associated diseases. Nonautoimmune thyroid diseases have no influence on the features of MG. The association of ocular MG and AITD might be due to a common autoimmune mechanism and/or a peculiar genetic background.

Abstract: Severe hyperparathyroidism due to parathyroid carcinoma and Hashimoto's thyroiditis was observed in a 69-yr-old Sardinian woman. To our knowledge, this association has not been reported so far. Given the high prevalence of autoimmune disease in elderly women, a random occurrence of the two conditions could represents the most probable explanation.

Abstract: We recently observed 2 lactase-deficient women with Graves' disease who consistently developed severe diarrhea after ingestion of thionamide (methimazole and propylthiouracil) tablets containing lactose as carrier. The strict temporal relationship between ingestion of lactose-containing tablets and appearance of intestinal symptoms, as well as the absence of side effects following ingestion of methimazole tablets without lactose as carrier, provided the clue for the diagnosis. To our knowledge, severe diarrhea resulting from carrier lactose has not been previously reported for antithyroid drugs, and should be considered in occasional cases of patients with gastrointestinal symptoms on thionamide therapy.

Abstract: We studied the hypothalamic-pituitary-thyroid function in two groups of healthy elderly subjects: group A (n = 23, age range 65-80 years), and group B (n = 11, age range 81-92 years), and in 32 controls, aged 20-60. A TRH test for TSH and prolactin was performed in all subjects, while the TSH circadian modulation was evaluated in elderly subjects only. Group B showed significantly lower fT3 and TSH, and higher fT4 levels with respect to controls (fT3: 4.4 +/- 0.2 vs. 5.2 +/- 0.2 pmol/l, p < 0.05; fT4: 13.1 +/- 0.9 vs. 11.4 +/- 0.4 pmol/l, p < 0.05; TSH: 1.07 +/- 0.21 vs. 1.46 +/- 0.13 mIU/l, p < 0.05). Morning TSH showed an inverse correlation with age (r = -0.42; p < 0.02) among the 34 elderly subjects, but not among controls. Evidence for TSH circadian modulation was found only in group A (nighttime TSH: 1.60 +/- 0.17, vs. daytime: 1.25 +/- 0.13 mIU/l, p < 0.001). The TRH-stimulated TSH peak was reduced among all elderly subjects with respect to controls (A: 6.26 +/- 0.64 mIU/l, p = 0.01; B: 5.02 +/- 0.58 mIU/l, p < 0.01). The maximal PRL response was also blunted (A: 25.7 +/- 2.6 micrograms/l, B: 27.7 +/- 5.2 micrograms/l, p < 0.0005). In conclusion, a resetting of the pituitary threshold of the TSH feedback suppression, along with complex alterations in peripheral thyroid hormone levels, may progressively develop in older people, becoming apparent only with extreme senescence. Moreover, the TSH nocturnal surge may be lost with increasing age, thus providing evidence also for hypothalamic dysfunction.

Abstract: Double-phase 99mTc-methoxyisobutylisonitrile (MIBI) parathyroid scintigraphy has been proposed to detect hyperplastic parathyroid tissue, but the clinical usefulness of this technique in secondary hyperparathyroidism is still debated. METHODS: Technetium-99m-MIBI parathyroid scintigraphy associated with parathyroid echography and [99mTc]pertechnetate thyroid scans were performed on 38 patients with chronic renal failure (CRF) and secondary hyperparathyroidism. In all patients, serum calcium, phosphorus, FT3, FT4, TSH, calcitonin and intact PTH (iPTH) were determined. Nine patients eventually underwent neck exploration and 28 parathyroid glands were removed. RESULTS: Thyroid diseases were excluded in all patients. Echography revealed parathyroid enlargement in 22/38 (58%) patients, while MIBI scintigraphy was positive in 28/38 (74%), including 5 ectopic glands. Mean serum iPTH concentration was significantly higher in MIBI-positive glands compared to MIBI-negative glands, but several discrepancies were observed in single patients. A significant positive correlation between serum iPTH and gland size was observed when MIBI-positive, but not MIBI-negative, parathyroids were considered. A paradoxical positive correlation between serum calcium and iPTH concentrations was found in MIBI-positive patients. CONCLUSION: Double-phase 99mTc-MIBI scintigraphy is positive in the majority of patients with uremic hyperparathyroidism. Comparison of scintigraphic data with morphological and functional data strongly suggests that 99mTc-MIBI scans do not reveal simple parathyroid enlargement but rather, identify the presence of hyperfunctioning (autonomous) parathyroid tissue suggestive of tertiary hyperparathyroidism.

Abstract: In recent decades, major theoretical and technological advances have been achieved in the field of immunology. These have allowed the scientific community to analyse the immune system in a much more sophisticated manner than was possible even 20 years ago. Moreover, great theoretical changes have also occurred in gerontology-in particular, the hypothesis has been put forward that ageing and diseases are two different phenomena, and that successful ageing, i.e. ageing in good psychophysical conditions, is really possible for most humans and animals. Immunosenescence was then carefully investigated, either in selected healthy people of advanced age or in the oldest old people, such as healthy centenarians. The main results showed that most immune parameters are indeed well preserved even at this far advanced age. This paper deals with some of the most important theoretical problems of immunosenescence. An immunological tenet was that the most important phenomenon of immunosenescence is the involution of the thymus. In most textbooks and papers it is taken for granted that the thymus starts its involution immediately after puberty. When people aged 60-65 were considered old, it was not difficult to think that they could live for the rest of their life with a fully involuted thymus. The findings on centenarians challenge this tenet, as they have only a small reduction of T lymphocytes, and a relatively normal number of virgin and memory T cells, together with a functional T cell repertoire. Other observations reported here on centenarians, concerning the activity of B lymphocytes and the cytokine network, as well as those on the well-preserved innate immunity and the cells' capability of undergoing proliferation after appropriate stimuli, suggest that complex immune changes occur with age, but also indicate that we have to modify our attitude, to grasp the new scenario which is emerging. Immunosenescence can no longer be considered as a unidirectional deterioration, and this complex phenomenon is much better described by terms such as 'remodelling', 'reshaping' or 'retuning'.

Abstract: Ageing is associated with the appearance of several serum autoantibodies, including thyroid autoantibodies. The biological and clinical significance of this phenomenon is still unknown, since, with the exception of primary myxedema, the prevalence of clinically overt thyroid autoimmune diseases is not increased in the elderly. The peculiar link between autoimmune thyroid failure and ageing is also underscored by the high prevalence of subclinical hypothyroidism in elderly subjects with positive serum thyroid autoantibodies, and could be the consequence of preferential age-dependent expression of destructive effector mechanisms and/or increased target gland susceptibility. Thyroid autoimmunity and subclinical hypothyroidism have also been implicated in the pathogenesis of other age-associated disorders, in particular coronary heart disease. Interestingly, recent data from our laboratories showed that thyroid autoantibodies are rare in healthy centenarians and in other highly selected aged populations, while they are frequently observed in unselected or hospitalized elderly. Taken together, these data suggest that thyroid autoimmune phenomena are not the consequence of the ageing process itself, but rather might be related to age-associated disease.

Abstract: Measurement of thyroglobulin (Tg) in serum with anti-Tg autoantibodies (TgAb) represents a difficult challenge. Immunoradiometric assays (IRMA) employing monoclonal anti-Tg antibodies not cross-reacting with endogenous TgAb have recently been developed and proposed for Tg assays in TgAb-positive sera. The aim of the present investigation was to assess the clinical reliability of this approach. Assays of serum Tg in patients with and without TgAb using one such monoclonal antibody IRMA (Thyroglobulin IRMA-Pasteur; IRMA-1) were compared with those obtained by a conventional IRMA employing polyclonal anti-Tg antibodies (HTGK-Sorin; IRMA-2). Preliminary studies for assessment of the interference of TgAb showed that the recovery of added Tg was significantly higher (P < 0.01) when determined by IRMA-1 (64.6 +/- 23%) than by IRMA-2 (49.5 +/- 20%). Study groups included 79 patients with differentiated thyroid carcinoma (DTC) treated by total thyroidectomy and radioiodine ablation; 24 had no metastases or residual thyroid tissue, 31 had a thyroid residue, and 24 had metastatic disease. Seventy-five patients with autoimmune thyroid disease (47 with Graves' and 28 with Hashimoto's disease) were also included. In TgAb-negative sera from DTC patients, similar Tg concentrations were found by both IRMA, i.e. undetectable in most patients with no residual thyroid or neoplastic tissue, low to moderately elevated in the majority of those with residual thyroid tissue, and markedly elevated in all patients with metastatic disease. Serum Tg was undetectable by both assays in several TgAb-positive sera from DTC patients with residual thyroid tissue or metastatic disease, respectively, in whom a detectable or even high serum Tg concentration was expected. Despite the lower in vitro interference of TgAb in IRMA-1, there was no difference between the two assays. In the group of patients with thyroid autoimmune disease, serum Tg concentrations were found to be high in TgAb-negative sera and much lower in TgAb-positive sera by both IRMAs. In conclusion, the present study demonstrates that the use of a monoclonal antibody IRMA for serum Tg, although less susceptible to in vitro TgAb interference, does not necessarily provide any substantial advantage with respect to a conventional polyclonal IRMA in detecting Tg in TgAb-positive sera. The finding of undetectable or lower than expected serum Tg by either method in TgAb-positive serum may well reflect a truly reduced serum Tg concentration. This might be due to an accelerated Tg metabolic clearance in the presence of TgAb.(ABSTRACT TRUNCATED AT 400 WORDS)

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Abstract: The thyroid gland is the target of several autoimmune diseases. Specific thyroid proteins have been identified as autoantigens associated with these diseases (e.g. thyroperoxidase, thyroglobulin and the thyrotrophin (TSH) receptor). In this paper, we report that the serum of a patient suffering from Hashimoto's thyroiditis, autoimmune gastritis and rheumatoid arthritis was able to inhibit the chronic TSH-induced I- uptake of dog thyrocytes in culture, even at a 1:1000-fold dilution, without affecting their 86Rb+ uptake. This blocking activity is rare as 147 sera (from patients positive for antibodies to the thyroid microsomes and the gastric parietal cell antigen, patients with Sjögren's syndrome, patients with a high titre of microsomal antibodies and low or negative for antibodies to thyroperoxidase, and patients with a high titre of microsomal antibodies and frank hypothyroidism) were negative when tested for their ability to inhibit I- uptake. Subsequently we tested 20 murine monoclonal antibodies previously obtained by immunizing mice with a crude human thyroid membrane preparation, which were all negative when tested against thyroglobulin and thyroperoxidase. One of the monoclonal antibodies displayed a 50% inhibition of the chronic TSH-induced 125I- uptake of dog thyrocytes without affecting the 86Rb+ uptake of the cells. Immunoglobulins purified from the ascite fluid by affinity chromatography on a protein A cellulose column had the same characteristics. Taken together, the data suggest that thyroidal 125I- uptake can be inhibited by antibodies, that autoantibodies in the patient's serum are most probably responsible for the observed inhibition and therefore that the Na+/I- cotransporter is probably an autoantigen.

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Abstract: Thyroglobulin antibodies (TgAbs) are typically found in autoimmune thyroid diseases and, more rarely, in nonautoimmune thyroid diseases and healthy subjects. To determine whether TgAbs associated with different conditions recognize different epitopes on the thyroglobulin molecule, we studied 28 patients with Hashimoto's thyroiditis, 30 with Graves' disease, 21 with thyroid carcinoma, 18 with nontoxic goiter, and 25 healthy subjects. All patients were selected for the presence of TgAbs; 4/25 healthy subjects also had TgAbs. The sera were assayed for the their ability to inhibit the binding of monoclonal antibodies to thyroglobulin in an ELISA assay. We found that: 1) TgAbs in Hashimoto's patients preferentially recognized three clusters of epitopes (II, III and typically VI), with no difference between the goitrous and the atrophic variants; 2) TgAbs in Graves' patients were directed toward cluster II, with no difference between the presence or the absence of ophthalmopathy; 3) TgAbs in thyroid carcinoma patients recognized the same clusters as Hashimoto's patients; 4) TgAbs in nontoxic goiter patients and in the four healthy subjects showed no restriction in epitope recognition. We suggest that in individuals with no overt clinical or biochemical thyroid abnormalities but with TgAbs, the finding that these TgAbs recognize particular immunodominant clusters may be utilized to predict full-blown thyroid disorders. Longitudinal studies are needed to evaluate the possible clinical application of this methodology.

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Abstract: Increased concentrations of serum soluble interleukin-2 (IL-2) receptor (sIL-2R), a marker of T-lymphocyte activation, have been found in several metastatic solid tumors. To our knowledge, no information is available on serum sIL-2R in differentiated thyroid carcinoma (DTC). Aim of this study was to evaluate whether disease activity and/or thyroid status may affect circulating sIL-2R in DTC, since it is has recently been demonstrated that serum thyroid hormone concentration positively modulates circulating sIL-2R. DTC patients were divided into 3 groups: Group A: 48 patients without metastases or local recurrences; Group B: 16 patients with cervical lymph node metastases; Group C: 22 patients with distant metastases. All patients were evaluated after total thyroidectomy both off and on L-thyroxine (L-T4) therapy. Control group was composed by 20 healthy euthyroid subjects. sIL-2R was assayed by solid-phase ELISA. In the hypothyroid state, sIL-2R levels of Group A were significantly lower when compared to normal controls (256 +/- 130 vs. 461 +/- 186 U/ml, p < 0.001 by Student t test); Group B and Group C patients off L-T4 therapy had sIL-2R concentrations significantly higher (479 +/- 407 U/ml, Group B; 519 +/- 746 U/ml, Group C) when compared to hypothyroid patients of Group A (p < 0.01 and p < 0.05, respectively), but not significantly different from normal euthyroid controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Abstract: OBJECTIVE: Anti-thyroid peroxidase autoantibody (anti-TPO) and anti-thyroid microsomal antibody (anti-M) are strictly related, but discrepancies are sometimes observed. The aim of this study was to assess the incidence and to identify the causes of these discrepancies. DESIGN AND ANTIBODY MEASUREMENTS: Anti-M by passive hemagglutination and anti-TPO by two competitive monoclonal antibody-assisted radioimmunoassays (RIA-1 and RIA-2) were measured in 10,103 sera from 4232 subjects (663 male, 3569 female) screened for thyroid disease. RESULTS: Anti-TPO and anti-M correlated quite well (r = 0.7 and p < 0.0001 by RIA-1: r = 0.74 and p < 0.0001 by RIA-2), with discrepancies mostly limited to sera with low antibody titers. After exclusion of the latter samples, anti-TPO were detected in only 79 (1.4%) out of 5317 anti-M negative sera, but were undetectable in a more consistent proportion (130/2880 = 4.5%) of sera from patients with autoimmune thyroid disease and positive anti-M. In 61 sera of the latter group, anti-TPO was measured by a non-competitive RIA (RIA-3). Forty-one (67.7%) were positive by RIA-3, suggesting the presence of anti-TPO not competing with the monoclonal antibodies of RIA-1 and RIA-2. The remaining 20 sera had undetectable anti-TPO also by RIA-3. Nineteen (95%) of these sera had positive anti-thyroglobulin (anti-Tg) autoantibody and preincubation with thyroglobulin inhibited the agglutination reaction of anti-M tests. CONCLUSION: Anti-TPO by competitive monoclonal antibody-assisted RIA is negative in a minority of sera of patients with autoimmune thyroid disease and positive anti-M. This could be accounted for by anti-Tg producing false positives in the anti-M assay and by a subset of anti-TPO not competing with the monoclonal antibodies in the RIA. When autoimmune thyroid disease is suspected on clinical grounds, a negative anti-TPO test with a competitive RIA should be confirmed always by a non-competitive assay.

Abstract: The IgG subclass distribution of thyroglobulin antibodies (TgAb) has been studied in Hashimoto and Graves' patients by several investigators with conflicting results, in part explainable by methodological problems. We have recently developed a quantitative ELISA to measure in absolute terms the serum concentration of TgAb subclasses. The aim of the present study was to apply this method in a large series of patients with autoimmune as well as, for the first time, non-autoimmune thyroid diseases. We examined 28 patients with Hashimoto's thyroiditis, 30 with Graves' disease, 21 with thyroid carcinoma and 18 with non-toxic goitre, all selected for the presence of TgAbs. The results indicated that TgAbs in thyroid diseases were not restricted to any particular isotype, but comprised all four IgG subclasses. IgG1 was represented similarly in the four groups. The same was true for IgG3, even though its contribution to the total antibody content was very small. IgG4 was the dominant subclass in patients with Graves' disease, thyroid carcinoma and non-toxic goitre, probably reflecting a prolonged antigenic challenge. In Hashimoto's thyroiditis IgG2 was dominant, possibly because T helper lymphocytes infiltrating the thyroid are typically Th1 type.

Abstract: Tryptic peptides of human thyroglobulin (Tg) were analysed by Western immunoblot for their reactivity to circulating autoantibodies from patients with Hashimoto's thyroiditis (HT), Graves' disease (GD) and thyroid carcinoma, and from normal human controls. Low molecular weight peptides were released after 4 h incubation of Tg with trypsin. The sera of thyroid disease patients reacted with several peptides, but predominantly bound three peptides with apparent molecular weights (MWap) of 25 kD, 20 kD, and 15 kD; the sera of normal individuals did not bind these fragments of Tg. The pattern of tryptic peptides recognized by the majority of sera from GD patients differed from that recognized by sera from most patients with HT. Autoantibodies from both groups of patients recognized a 15-kD peptide with a high frequency, but the sera from 26/43 (60%) GD patients also recognized a peptide with MWap of 25 kD, whereas the sera from 22/35 (63%) of HT patients recognized a 20-kD peptide. A few sera from patients with thyroid carcinoma reacted with peptides with MWap of 15 and 20-kD, and none bound the 25-kD peptide. The immunoreactivity of autoantibodies in HT sera to the 20-kD peptide paralleled the competitive inhibition of the MoAb 137C1 by these sera. In addition, MoAb 137C1 and Hashimoto's sera showed the same Western immunoblot-binding pattern to Tg tryptic peptides, suggesting that a Hashimoto-associated epitope and the 137C1-binding site are found on the same peptide. These findings suggest that distinct peptides are recognized by Tg autoantibodies from patients with different thyroid diseases.

Abstract: Major histocompatibility class II molecules human leukocyte antigen-DR (HLA-DR) are abnormally expressed by human thyroid cells (HTC) in autoimmune thyroid glands. The simultaneous expression of HLA-DR and organ-specific autoantigens such as thyroid peroxidase (TPO) by HTC might enable these cells to function as antigen-presenting cells, thus perpetuating the autoimmune process. The aim of the present study was to clarify the interplay of endocrine (TSH) and immune [TSab or interferon-gamma (IFN gamma)] factors on the expression of HLA-DR and TPO in HTC. Thyrocytes were cultured with supernatants of T-cells cloned from the infiltrate of Hashimoto's glands, human recombinant IFN gamma, TSab, or TSH. These factors were added either alone or in different combinations and sequences. HLA-DR and TPO were identified in HTC by a double indirect immunofluorescence technique, using a monoclonal anti-HLA-DR antibody and human serum containing anti-TPO antibody, respectively. IFN gamma, either recombinant or produced by T-cell clones, induced HLA-DR appearance in thyrocytes, whereas TSH or TSab stimulated TPO expression. The appearance of HLA-DR induced by IFN gamma was accompanied by a progressive reduction of TPO despite stimulation by TSH or TSab. This decline reached a nadir after 9-10 days in different primary cultures. During this period, a percentage of cells ranging from 10-40% simultaneously expressed HLA-DR and TPO on their surface and in the cytoplasm. The inhibition of TPO expression and the appearance of HLA-DR induced by IFN gamma were rapidly reverted when TSH or TSab was substituted for interleukin in the culture medium and vice versa. We conclude that 1) the expression of TPO or HLA-DR in thyroid cells is a dynamic phenomenon that is differently influenced by TSH, TSab, and IFN gamma. It is the interplay of these factors in different follicles and during different periods of time that determines the expression of TPO alone, HLA-DR alone, or both molecules together in the same thyroid cell; 2) during exposure to TSH (or TSab) and IFN gamma, TPO and HLA-DR can be expressed simultaneously by thyroid cells for up to 7 days; and 3) the modulation of HLA-DR and TPO by supernatants of T-cells cloned from Hashimoto's glands is reproduced by IFN gamma alone.

Abstract: Lymphocytic infiltration of muscular and connective tissues of the retroorbital (RO) space is a histological hallmark of Graves' ophthalmopathy (GO). We have characterized some phenotypical and functional features of T cells derived from RO infiltrates of four GO patients who were submitted to orbital decompression. Fragments of RO tissue were cultured for 7 days in IL-2-conditioned medium in order to generate T cell lines of in vivo activated T cells. Phenotypical analysis of freshly isolated peripheral blood (PB) lymphocytes both from patients and four healthy controls showed a predominance of CD4+ T cells (CD4/CD8 ratios 1.9:2.5), whereas RO-derived T cell lines displayed almost equal proportions of CD4+ and CD8+ cells (CD4/CD8 ratios 0.9:1.2). RO T cell lines and PB T cells from patients and controls were then cloned using a high-efficiency cloning procedure. The phenotypical and functional features of 153 T cell clones (TCC) derived from RO infiltrates were examined and compared with those of 166 and 236 TCC derived from the PB of patients and controls, respectively. CD4/CD8 ratios ranged from 0.8-1.4 in the series of RO-derived TCC and from 1.9-2.2 in the corresponding series of PB-derived TCC. Assessment of lectin-dependent cytolytic activity showed similar proportions of cytotoxic clones in TCC derived from the PB of patients (37%) and controls (38%); most of the cytolytic TCC was CD8+. In contrast, the proportion of cytolytic RO TCC was markedly higher (106/153 = 69%), including 100% of CD8+ and the majority (59/79 = 75%) of CD4+ clones. When compared to TCC derived from the PB of both patients and controls, RO TCC showed remarkably high proportions of both CD8+ and CD4+ clones with a Th1-like cytokine profile, as documented by their ability to secrete IL-2, IFN-gamma, and tumor necrosis factor-alpha (TNF-alpha), but not IL-4 or IL-5. This study provides evidence that cytolytic T cells with Th1 profile of cytokine production predominate in RO infiltrates of GO, a pattern quite similar to those previously described in thyroid infiltrates of Hashimoto's thyroiditis or Graves' disease. The peculiar cytokine secretion profile of RO T cells may be of importance in the pathogenesis of both the tissue alterations and fibrogenic process observed in GO.

Abstract: The present report illustrates the clinical and biochemical outcome in two amiodarone iodine-induced thyrotoxicosis (AIIT) patients submitted to plasmapheresis. Amiodarone was discontinued, and treatment with MMI (40 mg/day) was started. In addition, patients were submitted to two sessions of plasma-exchange, with a one-day interval between the two session. In both patients serum total T3 (TT3) and free T3 (FT3) concentrations decreased promptly but in contrast to the serum TT3, FT3 levels remained steadily above the normal range. A similar behaviour was observed for total T4 and free T4 plasma concentrations. Interestingly, a clearcut clinical amelioration was observed in both patients even before a reduction of circulating free thyroid hormone concentrations could be documented. In conclusion, our experience indicates that plasmapheresis may be useful in order to obtain a rapid amelioration of severe clinical picture of thyrotoxicosis, but cannot be considered as a definite therapy in AIIT. It should be considered that plasmapheresis is not devoid of risks and is also a very expensive procedure.

Abstract: The aim of this paper is to synthetically focus on current views on the use of radioiodine for the treatment of hyperthyroidism in single autonomously functioning thyroid nodules (AFN). Radioiodine administration represents a simple and effective alternative to surgical ablation of AFN, especially in elderly patients with small nodules (< 3 cm diameter). Radioiodine is very selectively accumulated in the thyroid, where it can deliver its energy without virtually affecting any other organ. Since its first use in 1942, 131I is (as Na131I) still the radioisotope of choice, due to easy availability and to its peculiar physical characteristics. These include a short half-life (8 days) and a spectrum of radiation (mainly of the beta type) with an optimal energy delivery in the nodule and with low penetration in the surrounding tissue. The effectiveness of radioiodine administration in permanently correcting hyperthyroidism in AFN has been demonstrated in many studies and may reach 80% with a single dose administration. The optimal dose has not been completely defined, but may be empirically calculated taking into account the weight of the nodule (evaluated by scintiscan or ultrasound) and the radioiodine uptake after 24 hours. In our and in many other institutions, indications to radioiodine treatment are currently the following: age > 35-40 years, diameter of the nodule < 3 cm and/or serious general diseases contraindicating surgical treatment. The only absolute contraindication to radioiodine treatment is pregnancy, due to the possible mutagenic effects on the foetus and to the extreme sensitivity of the foetal thyroid to radioiodine after the 10th week of gestation.(ABSTRACT TRUNCATED AT 250 WORDS)

Abstract: Several changes in thyroid function have been described in the elderly and largely attributed to concomitant nonthyroidal illness. The extent to which aging per se contributes to these changes remains to be elucidated, and scanty data are available in extremely old subjects. The present study was designed to focus on thyroid function during physiological aging, taking advantage of two groups of selected aged individuals: group A of healthy centenarians (n = 41; age range, 100-110 yr) and group B including healthy elderly subjects selected by the criteria of the EURAGE SENIEUR protocol (n = 33; age range, 65-80 yr). Control groups included 98 healthy normal adult subjects (group C; age range, 20-64 yr) and 52 patients with miscellaneous nonthyroidal illness (group D; age range, 28-82 yr). Our previous report of a low prevalence of thyroid autoantibodies in centenarians was confirmed and extended by the finding of a similar low autoantibody prevalence in the highly selected healthy elderly population of group B. Subclinical primary hypothyroidism was found in 3 (7.3%) centenarians, and their data were excluded from further statistical evaluation. No significant difference was found in the median serum free T4 levels of groups A-C. Median (and range) serum free T3 (FT3) was lower in centenarians [3.67 pmol/L (2.3-5.5)] than in group B [5.22 pmol/L (3.4-6.1)] and group C [5.38 pmol/L (2.9-8.4); P < 0.0001 vs. both groups]. Similarly, the median serum TSH level of centenarians [0.97 mU/L (< 0.09 to 2.28)] was lower than those in groups B [1.17 mU/L (0.53-2.74)] and C [1.7 mU/L (0.4-4.8); P < 0.0001 vs. both groups]; moreover, serum TSH was also significantly (P < 0.01) lower in group B than in group C. Both serum FT3 and TSH concentrations showed a significant inverse correlation (r = -0.634; P < 0.0001 and r = -0.377; P < 0.0001, respectively) with age. Median serum FT3 in centenarians was lower than that in group D patients [4.61 pmol/L (2.15-6.6); P < 0.0001]. In contrast, median serum rT3 in centenarians [0.40 nmol/L (0.20-0.77)], although higher than those in groups B [0.24 nmol/L (0.15-0.37); P < 0.0001] and C [0.22 nmol/L (0.05-0.46); P < 0.0001], was significantly lower than that in group D [0.60 nmol/L (0.13-2.08); P < 0.0001]. In conclusion, thyroid function appears to be well preserved until the eighth decade of life if healthy subjects are studied, whereas a reduction of serum FT3 is observed in extreme aging.(ABSTRACT TRUNCATED AT 400 WORDS)

Abstract: OBJECTIVE: The serum concentration of soluble interleukin-2 receptor (sIL-2R) is a marker of T-lymphocyte activation. Increased circulating sIL-2R has been reported in untreated Graves' disease. This finding has been interpreted as the consequence of the autoimmune activation, but recent data suggest that sIL-2R is directly correlated to thyroid state. The aim of this study was to elucidate the respective roles of autoimmunity and thyroid function in modulating serum sIL-2R. DESIGN AND PATIENTS: sIL-2R was evaluated in 20 normal euthyroid subjects and in a large series of patients with autoimmune and non-autoimmune thyroid disorders in different functional state. MEASUREMENTS: sIL-2R was assayed by a solid-phase monoclonal antibody assisted ELISA method. RESULTS: Serum sIL-2R in normals was 461 +/- 186 U/ml (mean +/- SD). Increased sIL-2R was found in 61 hyperthyroid patients with Graves' disease (1610 +/- 962 U/ml, P < 0.0001) and in 23 with toxic adenoma (1121 +/- 598 U/ml, P < 0.0001). Restoration of euthyroidism lowered to normal sIL-2R in both groups. Serum sIL-2R was higher in euthyroid Graves' disease patients with active than in those with non-active ophthalmopathy. Decreased serum sIL-2R (228 +/- 93 U/ml, P < 0.0001) was found in 30 patients hypothyroid after total thyroidectomy. Highly variable circulating sIL-2R (range 100-1456 U/ml, mean +/- SD: 379 +/- 301 U/ml) was found in 49 patients with hypothyroid Hashimoto's thyroiditis (P = NS vs normals; P < 0.02 vs post-thyroidectomy hypothyroid patients). Treatment with L-thyroxine increased sIL-2R in all thyroidectomized and in the majority of Hashimoto's thyroiditis patients. In individual Hashimoto's thyroiditis patients (mostly with increased serum sIL-2R), L-thyroxine caused a decrease of circulating sIL-2R, sIL-2R was normal in 29 patients with euthyroid Hashimoto's thyroiditis. Both in Graves' disease and in Hashimoto's thyroiditis, no correlation was found between sIL-2R and anti-thyroglobulin, anti-thyroid peroxidase and anti-thyrotrophin-receptor autoantibodies. Highly significant positive correlation between serum thyroid hormones and sIL-2R was found in all study groups. CONCLUSIONS: In thyroid disorders thyroid hormones are the main regulator of serum sIL-2R concentration. The contribution of autoimmune activation may be detected only in some patients with autoimmune hypothyroidism, while in Graves' disease the role of the immune system is masked by the hyperthyroid state.

Abstract: To investigate the prevalence of thyroid autoantibodies in very old subjects, we assayed sera from 34 healthy centenarians (7 men, 27 women; age range 100-108 years) for these antibodies. There was a clear age-dependent increase in prevalence of thyroid autoantibodies in sera from 549 control subjects aged 7-85 years, prevalence in 40 subjects aged 70-85 being significantly greater (p less than 0.001, chi 2) than that in 436 subjects aged less than 50. By contrast, prevalence of thyroid autoantibodies in centenarians was not significantly different from that in controls aged less than 50. Cytofluorimetric analysis of peripheral blood lymphocytes showed a striking age-dependent decrease in total and CD5+B cells (without changes in their ratio), which reached its nadir in centenarians. The age-dependent increase in prevalence of thyroid autoantibodies in the elderly is not seen after the ninth decade of life. What relation this characteristic has to derangement of circulating B cells is unknown.

Abstract: High serum concentration of soluble interleukin-2 receptor (sIL-2R) is considered a reliable marker of T lymphocyte activation. It has been recently reported that sIL-2R levels are increased in untreated Graves' disease. This finding has been interpreted as the consequence of an active autoimmune state, but the relevance of the thyroid function per se was not investigated. In the present study we assayed sIL-2R by ELISA in 20 normal subjects and in a series of patients with immunogenic (Graves' disease, GD) or nonimmunogenic (toxic adenoma, TA) hyperthyroidism. Significant increased concentrations of sIL-2R were found in 46 patients with untreated hyperthyroid GD (mean +/- SD: 1,683 +/- 1016 U/ml, vs 461 +/- 186 U/ml in normal controls, p less than 0.0001) and in 21 with untreated TA (1,111 +/- 617 U/ml, p less than 0.0001 vs normals). Restoration of the euthyroid state by antithyroid drugs or 131I administration was associated with a normalization of sIL-2R (516 +/- 174 U/ml in 38 patients with GD and 365 +/- 90 U/ml in 12 with TA; p = NS vs normals and p less than 0.001 vs the untreated state for both groups). A highly significant positive correlation between serum sIL-2R and free triiodothyronine (FT3) (r = 0.724, p less than 0.0001) or free thyroxine (FT4) (r = 0.698, p less than 0.0001) concentrations was found in combined sera obtained from all untreated and treated patients, irrespectively of the autoimmune or nonautoimmune nature of the underlying hyperthyroid disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Abstract: The availability of high efficiency T-cell cloning techniques recently allowed the identification and characterization of clones derived from the thyroid infiltrate of patients with autoimmune thyroid diseases. Phenotypical and functional analysis of T-cell clones obtained from thyroid infiltrates of patients with Hashimoto's thyroiditis show that most of them are progenies of CD8+ cytolytic T cells with natural killer activity. This phenomenon, of potential importance in tissue damage, is markedly less pronounced in Basedow's disease glands. In both Hashimoto's thyroiditis and Basedow's disease only a minority of clones appear to be specific for autologous thyroid cells and most of them are potent interferon-gamma producers, while increased secretion of tumor necrosis factor-alpha is observed only in Hashimoto's thyroiditis. In contrast with normal lymphoid tissue, only very few T cell clones derived from both BD and HT infiltrates were able to produce detectable amounts of IL-4, suggesting that most of the thyroid-infiltrating T cells represent quite homogeneous populations of Th1-type "inflammatory" T cells. This peculiar potential of lymphokine secretion could play a role in the expression and/or maintenance of thyroid autoimmunity and thyroid functional damage.

Abstract: In a previous work we characterized a major epitope of thyroid peroxidase (TPO), which was recognised by 66% of 157 patients with autoimmune thyroid disease (AITD) and 9 out of 50 patients with non-thyroidal autoimmune disease (NTAID) 6 of whom had antibodies to the gastric parietal cell antigen (PCA). In the present study we have affinity purified C2 antibodies and demonstrated that they bind to the native TPO enzyme in a radioimmunoassay (RIA). We have measured antibodies to the C2 peptide and a second TPO peptide, C21, in enzyme-linked immunosorbent assays (ELISA) in 30 patients with NTAID all of whom have antibodies to the gastric PCA, having first determined the incidence of antibodies to C21 in 98 patients with AITD who do not have antibodies to the gastric PCA. 58% of patients with AITD have antibodies to C21, a peptide of TPO which overlaps C2 by 21 amino acids in the region containing an 11 residue fragment which is very similar to a fragment of the H+ K+ ATPase, which has recently been shown to be a major component of the gastric PCA. In patients having NTAID and antibodies to the gastric PCA, 60% are positive for C2 Ab and 100% for C21 Ab, which is suggestive of an epitope shared by TPO and H+ K+ ATPase, corresponding to TPO 659----669 and H+ K+ ATPase 177----187. We conclude that C2 antibodies are heterogenous and comprise activities which bind to the intact enzyme and activities binding to an epitope which may be common to TPO and H+ K+ ATPase.

Abstract: While it is well established that autoimmune factors are the cause of goiter and hyperthyroidism in Graves' disease, these factors are not yet considered relevant in the development of thyroid autonomy. While an increased overall frequency of anti-Tg and anti-TPO antibodies has been found in moderate iodine-deficient areas, where thyroid autonomy is more frequently observed, there was evidence indicating that thyroid autoimmune phenomena were the consequence rather than the cause of the goiter. Thyroid Stimulating Antibodies (TSAb) have been reported in sera of patients with nodular autonomous goiter, but their pathogenetic relevance is uncertain, since these findings could not be confirmed by others. In our experience TSAb were detected in few cases with multinodular nontoxic goiter and were always associated with anti-TG and anti TPO antibodies, indicating that these patients have the nodular variant of Graves' disease. Besides TSAb, Thyroid Growth Stimulating Antibodies (TGAb) have been detected by different techniques in several goitrous conditions, including Graves' disease and sporadic or endemic nontoxic goiter. The precise nature of TGAb remains to be clarified, and particularly the relationship between TGAb and TSAb is still a matter of controversy. However, data indicating that TGAb cannot be dissociated from TSAb in Graves' sera suggest that these antibodies can be regarded as a sufficient pathogenetic agent for the development of both goiter and thyroid hyperfunction in Graves' disease. The relevance of TGAb in euthyroid goitrous conditions is uncertain, since conflicting results have been reported.(ABSTRACT TRUNCATED AT 250 WORDS)

Abstract: To evaluate possible immunological mechanisms involved in the development of postpartum thyroiditis with transient hyperthyroidism followed by transient hypothyroidism (PPT), antithyroid peroxidase antibodies (anti-TPO), antimicrosomal antibody (AMA) related immunoglobin G subclass and antibody-dependent cell-mediated cytotoxicity (ADCC) were studied in 43 post-partum (PP) women who were euthyroid at delivery and completed a subsequent 1 year follow up. Among the 25 mothers who developed PPT, 14 had positive AMA (PPT:AMA+) and 11 negative AMA (PPT:AMA-) at delivery. Among the 18 mothers who remained euthyroid (E) up to one year post-partum and were used as controls, 8 were AMA positive (E:AMA+) and 10 AMA negative (E:AMA-) at delivery. AMA measured by a hemagglutination method correlated well with anti-TPO antibodies measured by RIA in the PP mothers studied. When AMA-related IgG subclass activity was analysed comparing PPT women with appropriate euthyroid controls at the different time intervals studied, it was seen that PPT:AMA+ when compared to E:AMA+ women have significantly increased activity of AMA related IgG1 at all PP time intervals studied (p less than 0.001), but IgG4 was only increased at 5-7 months PP (p less than 0.05). PPT:AMA-when compared to E:AMA- have significantly increased IgG4 at 2-4 (p less than 0.001), 5-7 and 10-12 (p less than 0.05) months PP, but IgG1 is only increased at 5-7 months PP (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Abstract: Multiple sclerosis (MS) is associated with complex abnormalities of immunoregulation and a role of autoimmunity in its pathogenesis has been accepted. MS is reportedly associated with several autoimmune diseases, but few studies are available on the prevalence of organ-specific autoantibodies in this condition. The aim of this study was to assess the frequency of anti-thyroglobulin (TgAb), anti-thyroid microsomal (MAb) and gastric parietal cell (PCA) antibodies in 113 patients (63 females, 50 males, age ranging 15-62 years) with MS and in 51 neurological controls. The diagnosis of MS was made according to McDonald and Halliday criteria. TgAb and/or MAb were detected by passive hemagglutination in 19 (16.8%) patients with MS and in 3 (5.9%) of the controls. All positive TgAb and/or MAb were observed in MS females (19/63 = 30.1%), with significantly higher frequency than in female controls (X2 = 5.15, p less than 0.025). The presence of circulating thyroid antibodies was higher in patients with clinically definite or progressive probable MS and in those with long standing disease. In contrast with thyroid antibodies, no difference in the frequency of PCA, as assessed by radioimmunoassay, was observed between MS and controls. These data support a specific association between thyroid autoimmunity and MS. The appearance of thyroid autoimmune phenomena seems to be related to the reliability of the diagnosis of MS and the duration of the disease.

Abstract: Thyroid microsomal antibodies (anti-M Ab) have been recently proven to be directed to thyroid peroxidase (TPO). Methods to detect anti-TPO antibodies (anti-TPO Ab) employing purified antigen have been developed, but the available information on the clinical usefulness of this technique is still limited to small patient series. In the present investigation anti-TPO Ab were assayed by a newly developed monoclonal antibody-assisted RIA in a large number (n = 715) of subjects, including 119 normal controls and 596 patients with different autoimmune or nonautoimmune thyroid disease: Anti-TPO Ab were detected in 10 of 119 (8.4%; range, 11-210 U/mL) normal controls, 134 of 181 (74%; range, 11-74.000 U/mL) patients with Graves' disease, all but 1 of 144 (99.3%; range, 11-90.000 U/mL) with Hashimoto's thyroiditis (n - 98) or idiopathic myxedema (n = 46), 20 of 180 (11.1%; range, 11-6.700 U/mL) with miscellaneous nonautoimmune thyroid diseases, 16 of 83 (19.2%; range, 11-6.600 U/mL) patients with differentiated thyroid carcinoma, and in none of 8 patients with subacute thyroiditis. The highest anti-TPO Ab concentrations were found in untreated hypothyroid Hashimoto's thyroiditis, but no simple relationship between anti-TPO Ab levels and thyroid function was observed. Anti-TPO Ab significantly decreased in patients with Graves' disease after treatment with methimazole and in those with hypothyroid Hashimoto's thyroiditis or idiopathic myxedema during L-T4 administration. A highly significant positive correlation (r = 0.979; P less than 0.001) was found between anti-M Ab titers by passive hemagglutination (PH; available in 650 sera) and the corresponding average anti-TPO Ab by RIA; discrepant results were almost exclusively limited to sera with negative or low (1:100-1:400) anti-M Ab titers. Analysis of these discrepant data indicated higher autoimmune disease specificity and sensitivity of anti-TPO Ab RIA tests compared to anti-M Ab by PH. Absorption studies showed that interference of anti-Tg Ab was responsible for anti-M Ab-positive tests in occasional anti-TPO Ab-negative/anti-M Ab-positive sera from autoimmune thyroid disease patients. Anti-TPO Ab determination by RIA was unaffected by circulating thyroglobulin concentrations up to more than 10,000 ng/mL. In conclusion, anti-TPO Ab assay by monoclonal antibody-assisted RIA appears to be more sensitive and specific for thyroid autoimmune diseases than anti-M Ab determination by PH. Since the assay is easy to perform and employs only tracer amounts of purified antigen, these characteristics should allow its rapid diffusion to the clinical routine.

Abstract: The differential diagnosis of the various forms of inappropriate secretion of TSH (IST), i.e. generalized thyroid hormone resistance (GRTH), selective pituitary resistance [non-neoplastic IST (nnIST)], and tumoral pituitary TSH hypersecretion [neoplastic IST (nIST)], mainly rests on clinical observation, skull imaging, and measurement of several parameters assessing peripheral thyroid hormone effects. Clinically, patients with GRTH usually display compensated hypothyroidism, while those with nnIST or nIST are hyperthyroid. Since sex hormone-binding globulin (SHBG) measurement has been shown to be a reliable parameter in distinguishing between euthyroid and hyperthyroid states, we evaluated serum SHBG levels in 39 patients with IST (7 with GRTH, 15 with nnIST, and 17 with nIST). The results were compared to those in 68 normal subjects, 76 hyperthyroid patients, and 31 hypothyroid patients. SHBG levels in patients with either GRTH or nnIST were similar to those in controls or hypothyroid patients [GRTH, 40.5 +/- 11.8 (+/- SD) nmol/L (range, 26.4-57.5); nnIST, 29.7 +/- 12.8 nmol/L (range, 6.8-46.8); controls, 36.7 +/- 21.7 nmol/L (range, 5.4-96.5); hypothyroid, 30.8 +/- 14.4 nmol/L (range, 10.4-63.3)]. On the contrary, SHBG levels in patients with either overt hyperthyroidism or nIST were significantly higher than those in the above groups [hyperthyroid, 149 +/- 111 nmol/L (range, 48-557); nIST, 99.5 +/- 54.7 nmol/L (range, 21.6-259)]. The apparent overlap of SHBG values between hyperthyroid patients and controls almost completely disappeared when comparisons were made with control groups matched for age and sex. Additional indices of peripheral thyroid hormone action (basal metabolic rate, cardiac systolic time intervals, and Achilles' reflex time) were normal in patients with GRTH, while they were in the hyperthyroid range in patients with nnIST and nIST. After successful treatment of hyperthyroidism, SHBG levels normalized in patients with nIST, but they did not change in patients with nnIST. In conclusion, the measurement of SHBG in patients with IST is useful in differentiating the neoplastic form from that due to thyroid hormone resistance, but it fails to distinguish between generalized and pituitary resistance to thyroid hormone action. Moreover, the present data suggest that the resistance to thyroid hormone action in patients with nnIST is not selective at the thyrotroph cell level, but also involves the hepatic SHBG-synthesizing cells, thus supporting the view that the various forms of thyroid hormone resistance could represent a continuum of the same defect with variable expression in different tissues.

Abstract: T lymphocytes present in thyroid infiltrates of 6 patients with Hashimoto's thyroiditis (HT) and of 4 patients with Graves' disease (GD) were analyzed at clonal level and their profiles of mitogen-induced lymphokine secretion were characterized. Production of interleukin-2 (IL-2), interleukin-4 (IL-4), interferon-gamma (IFN-gamma) was measured in culture supernatants of a total number of 332 T cell clones (TCC) from HT, of 269 TCC from GD infiltrates and of 266 control TCC derived from normal lymphoid tissues. No significant difference was found in the ability to produce IL-2 between TCC from HT or GD infiltrates and control TCC. The proportion of HT- or GD-derived TCC able to produce IL-4 was extremely low (4 and 5%, respectively) in comparison with controls (19%). In contrast, the proportion of interferon-gamma (IFN-gamma)-producing (IFN-P) TCC derived from either HT (87%) or GD (80%) infiltrates was much higher (p less than 0.0005) than that found in controls (59%). In addition, most of IFN-P TCC from either HT or GD usually released higher amounts (p less than 0.002) of IFN-gamma than did control clones. No significant difference was found between GD infiltrates and controls in the proportions of TCC able to secrete TNF-alpha (39% and 47%, respectively), whereas the proportion of TNF-alpha-producing (TNF-P) TCC derived from HT (78%) was significantly higher (p less than 0.0001). In addition, most of both CD8 and CD4 TCC from HT released higher amounts of TNF-alpha than did TNF-P clones from controls or GD. These data suggest that T cells present in autoimmune thyroid infiltrates share a number of functions, such as high production of IFN-gamma, but differ with regard to their ability to secrete TNF-alpha, which is peculiar of most T cells present in the thyroid of HT patients.

Abstract: In this review new data are reported indicating that the thyroid microsomal-microvillar antigen can be identified with thyroid peroxidase (TPO). This concept derives from binding studies of monoclonal and polyclonal microsomal antibodies to TPO purified by affinity chromatography or obtained by recombinant DNA technology. Furthermore, immunofluorescence studies performed on cultured thyroid cells have shown the presence of a TPO-related antigen on the surface of the cells. The expression of the TPO antigen is modulated by TSH through the cAMP pathway. The functional activities of TSH receptor autoantibodies have also been characterized. From these studies the following conclusions can be drawn: (i) TSH receptor antibodies possess multiple biological activities, interfering or mimicking TSH actions; (ii) a good correlation is observed between stimulation of adenylate cyclase and of iodide uptake by Graves' IgG. In these IgG preparations, adenylate cyclase- and growth-stimulating activities cannot be separated; (iii) antibodies blocking the TSH-dependent AC are present in patients with autoimmune hypothyroidism; (iv) a mixture of stimulating and blocking antibodies may coexist in the same patient, whose clinical status may result from the sum of the biological activities of these antibodies. Finally, new data are reported on the identification and characterization of T cell clones infiltrating the thyroid tissue of subjects with thyroid autoimmune disorders. The majority of these clones were CD8+ cytolytic T cells with natural killer activity. These latter data may be of importance in the mechanisms of thyroid damage observed in Hashimoto's glands.

Abstract: The management of hyperthyroidism due to inappropriate secretion of TSH (IST) includes agents that selectively suppress TSH hypersecretion both in patients with TSH-secreting tumor [neoplastic IST (nIST)] in whom pituitary surgery was unsuccessful and in those with selective pituitary resistance to thyroid hormone action [nonneoplastic IST (nnIST)]. Among such agents, somatostatin administration has proven to be effective in blocking TSH hypersecretion, but its short plasma half-life prevented its use in long term therapeutic trials. The recent availability of a potent and long-acting analog of somatostatin (SMS 201-995, Sandostatin) prompted us to study its effects on serum TSH, alpha-subunit, and free thyroid hormone (FT4 and FT3) concentrations in five patients with nIST and three patients with nnIST. During short term SMS 201-995 administration (100 micrograms, sc, three times daily for 5 days) both serum TSH and alpha-subunit levels decreased in all patients with nIST (mean decrements, -86% and -85%, respectively), with concomitant normalization of serum FT4 and FT3 concentrations. In the three patients with nnIST, this treatment lowered serum TSH levels less well (mean decrement, -47%), although serum FT4 and FT3 levels normalized in one patient. Chronic SMS 201-995 (100 micrograms, sc, every 12 h for 1-7 months) treatment in four hyperthyroid patients (two with nIST and two with nnIST) resulted in a steady euthyroid state in both patients with nIST, with restoration of normal visual fields in one patient. In contrast, in both patients with nnIST, escape occurred after 2 weeks of therapy. We conclude that SMS 201-995 administration is effective treatment for patients with nIST, able to suppress TSH hypersecretion from the adenomatous thyrotrophs and, consequently, to restore clinical and biochemical euthyroidism in such patients. On the contrary, the inhibitory effects of SMS 201-995 on TSH secretion in patients with nnIST are weaker and transient.

Abstract: Humoral and cellular immune responses are both involved in autoimmune disorders of the thyroid gland. In the last five years, new substantial data have been obtained on the nature and the expression of thyroid cell surface autoantigens and on the demonstration of the functional heterogeneity of autoantibodies to the thyroid stimulating hormone (TSH) receptor. In the present report, attention will be mainly focused on recent studies carried out in our laboratory. The main autoantigens so far identified include the 'microsomal' antigen, thyroglobulin and the TSH receptor. For many years the 'microsomal' antigen (M) was considered a poorly characterized constituent of the cytoplasm of the thyroid cell. In the last five years, several lines of evidence were provided indicating that M is also well represented on the surface of the follicular cell and is identical to thyroid peroxidase (TPO). The use of anti-TPO monoclonal antibodies, presently available, have confirmed this antigenic identity. Microsomal (anti-TPO) antibodies are very useful markers of autoimmune thyroid disorders and are generally present in Hashimoto's thyroiditis, idiopathic myxedema and Graves' disease. TSH receptor antibodies (TRAb) are present in the sera of patients with Graves' disease. TRAb are able to stimulate thyroid adenylate cyclase and also to mimic TSH in its thyroid growth stimulation. Thus, these antibodies may have a pathogenetic role in goiter formation and in thyroid hyperfunction in Graves' disease. TRAb were also shown to inhibit both TSH binding to its receptor and TSH-stimulated adenylate cyclase activity. Recently TRAb, which inhibited TSH-stimulated adenylate cyclase activity, were found in idiopathic myxedema patients and may be responsible for impairment of thyroid function.(ABSTRACT TRUNCATED AT 250 WORDS)

Abstract: Previous studies carried out by screening a lambda gt11 human thyroid cDNA library with serum samples from selected patients with Hashimoto's thyroiditis and a polyclonal antibody to porcine thyroid peroxidase (TPO) confirmed, at the molecular level, that TPO is a major component of the thyroid microsomal antigen (M). That investigation led to the isolation of a clone (C2) which encodes an 85-amino acid segment of TPO and harbors a major epitope recognized by serum from several patients with autoimmune thyroid disease that contained anti-M autoantibodies (MAb). In this study, C2 antigen that was produced as a beta-galactosidase fusion protein was used to establish an enzyme-linked immunoabsorbent assay for the detection of anti-C2 autoantibodies (C2Ab). C2Ab then were assayed in 191 patients with different autoimmune and nonautoimmune thyroid disorders, and 50 patients with nonthyroidal autoimmune diseases. The results were compared with the titers of anti-TPO antibodies (TPOAb; as detected by monoclonal antibody-assisted RIA) and MAb (as detected by passive hemagglutination). Positive C2Ab was found in the serum of 85 of 136 (63%) patients whose serum contained TPOAb and/or MAb. A significant positive correlation was found between the levels of C2Ab and those of TPOAb (r = 0.76; P less than 0.001) or MAb (r = 0.69; P less than 0.001), which was independent of the type of underlying autoimmune thyroid disorder. Low levels of C2Ab also were found in 10 of 105 (9%) serum samples that did not contain TPOAb. Western blot analysis carried out on the latter samples showed that in 2 samples the apparent C2Ab reactivity was due to the presence of antibodies reacting with beta-galactosidase. In conclusion, we confirmed the validity of screening lambda gt11 cDNA human thyroid libraries to better characterize thyroid autoantigens and demonstrated the feasibility of using recombinant proteins to establish diagnostic assays for autoantibodies.

Abstract: Although thyroid microsomal antibodies (anti-MAb) have been recently proven to be directly to thyroid peroxidase (TPO), current methods for MAb detection still employ unpurified microsomal fractions. The authors have therefore developed and evaluated a specific radioimmunoassay (RIA) for autoantibodies to TPO (anti-TPO Ab) based on competitive inhibition of 125I-TPO to an anti-TPO monoclonal antibody coated on plastic microtiter wells (RIA-1) or tubes (RIA-2). Preliminary experiments showed that both assays were able to specifically detect anti-TPO Ab, while negative results were obtained with normal sera and with sera containing other organ- and non-organ-specific autoantibodies including anti-thyroglobulin antibodies (anti-TgAb). No significant difference in sensitivity, specificity and reproducibility was found between RIA-1 and RIA-2, and the results obtained with the two techniques were therefore pooled together. Anti-TPO Ab were then assayed in 110 normal controls and in 441 patients with different autoimmune (AITD) or non-autoimmune (N-AITD) thyroid diseases and compared to anti-M Ab as assessed by passive hemagglutination (PH). Positive anti-TPO Ab were observed in 4/110 (3.6 p. cent) normal controls, 88/117 (80 p. cent) patients with Graves' disease, 122/123 with Hashimoto's thyroiditis or idiopathic myxedema and 21/201 (10.4 p. cent) with miscellaneous N-AITD. A highly significant positive correlation (r = 0.91, p less than 0.0001) was found between anti-MAb by PH and anti-TPO Ab by RIA ;discrepant results were limited to sera with negative or low (1/100-1/400) anti-M Ab titers.(ABSTRACT TRUNCATED AT 250 WORDS)

Abstract: In the last few years a great deal of information on the etiopathogenetic aspects of organ-specific autoimmune diseases has been obtained from the extensive study of both animal models of experimental or spontaneous thyroiditis and of human thyroid autoimmune diseases. It has been clearly shown that genetic factors play a fundamental etiologic role. They are responsible for the dysregulation of the immune system and for the target organ susceptibility which favor the onset of the disease. Environmental factors are presumed to act as initiating or precipitating events, leading genetically predisposed individuals to thyroid autoimmunity. A number of immune mechanisms able to trigger autoimmune responses, such as antigenic cross-reactions and the aberrant expression of HLA class II molecules, have been suggested, but the definition of why and how they become operative requires further investigation. Data obtained from experimental models and from human thyroid diseases clearly indicate that the ongoing expansion of autoreactive T cells with specificity for thyroid autoantigens represents the main immunological event responsible for induction and maintenance of thyroid damage. Such autoreactive T cells can induce tissue lesions through activation of different effector systems and secretion of different combinations of lymphokines. In overt thyroid autoimmune diseases autoantibodies directed against functional molecules or cellular receptors can also be involved in the pathogenesis of tissue lesions. However, the pathogenesis of inflammatory destructive lesions of the thyroid is more complex and not yet fully elucidated. It is worthy of note that a large proportion of T cells present in inflammatory human thyroid infiltrates are apparently not directed against the thyroid autoantigens recognized so far.(ABSTRACT TRUNCATED AT 250 WORDS)

Abstract: A good body of experimental and clinical evidences suggests that bidirectional interactions do exist between the neuroendocrine system and the thymus activity. In particular, thymic endocrine activity seems to be strongly influenced by neuroendocrine signals. In this context, studies performed in hyper- and hypothyroid subjects and in the low triiodothyronine (T3) syndrome, which affects premature infants, have clearly shown that thyroid hormones and in particular T3 physiologically modulate thymic peptide secretion. In vitro experiments, with thymic whole-organ cultures, have demonstrated that thyroid hormones exert their action on the epithelial cells of the thymus deputed to synthesize and secrete thymic peptides and that such an effect does not seem to depend on the known permissive action of thyroid hormones.

Abstract:

Abstract: Inappropriate thyrotropin secretion (IST) may originate from either neoplastic disease (nIST) or non-neoplastic resistance to thyroid hormone (nnIST). An inhibitory effect of somatostatin on TSH secretion has been documented. In an attempt to elucidate the possible therapeutic effect of this peptide on nIST and nnIST, a study was conducted in 7 such patients. Sandostatin (SMS 201-995) was administered in daily doses of 100 micrograms for several days to 1 month. Four patients with nIST responded with a fall in circulating TSH as well as alpha-subunit with concomitant normalization of free thyroxine and clear symptomatic improvement. In the 3 nnIST patients this effect was considerably less apparent and a partial TSH escape was observed on long-term treatment in 2 cases. The importance of somatostatin and its analogs in the management of thyroid malignancy is stressed.

Abstract: Although recently the human thyroid microsomal antigen (M-Ag) has been possibly identified as the thyroid peroxidase, its nature remained unknown over almost three decades. One of the difficulties encountered in the identification of M-Ag derived from the conflicting data obtained in the attempts to solubilize active antigenic material from thyroid subcellular fractions. In particular, following detergent treatment, M-Ag could not be detected by complement fixation, while a full recovery of the antigen has been observed using a radioassay technique. In the present investigation, the antigenic activity of Triton X-100 solubilized thyroid microsomes was assessed in parallel by complement fixation and radioassay methods employing the same anti-microsomal antibody (anti-M Ab) preparation for antigen detection. In untreated microsomes antigenic activity was detected by both methods. In contrast, detergent solubilized M-Ag was detected by radioassay, but could not be detected by complement fixation. These data indicate that detergent solubilization diminishes the complement fixing capacity of M-Ag, while the solubilized antigen can still be fully detected by its binding reaction with the autoantibody, and explain the discrepant results obtained in previous studies.

Abstract: Autoimmune thyroid disease associated to Sjögren syndrome (SS) may be defined by serological and functional abnormalities. We studied the prevalence of serum anti-thyroid autoantibodies and the development of thyroid functional defects by a follow-up investigation in patients with primary (pSS) and secondary SS (sSS). In keeping with previous literature data, our findings confirmed an increased prevalence of thyroid autoimmune phenomena in the whole series of patients with SS. In addition, evidence was provided for a greater incidence of serological and functional thyroid abnormalities in pSS when compared to sSS. Follow-up study also showed that the rate of thyroid autoimmune disease development was higher in pSS than in sSS. The appearance of circulating anti-thyroid antibodies was particularly frequent in patients with preexisting antibodies against extractable nuclear antigens (anti-ENA). These data indicate the need for a careful monitoring of thyroid function in SS patients, with particular regard to those with pSS and positive anti-ENA tests.

Abstract: In the present investigation we studied serum anti-thyroglobulin and anti-thyroid microsomal autoantibodies, measured by hemagglutination technique, in 600 patients with thyroid cancer seen by us from 1975 to 1985 (mean follow-up 46 months). Positive thyroglobulin antibodies and/or microsomal antibodies were found in 138 (23%) patients (23.9% with papillary, 25% with follicular, 16.1% with anaplastic, and 4.1% with medullary thyroid carcinomas). The incidence of positive tests was similar in each decade of life (ranging between 21.9% and 27.9%), whereas in a normal sex-matched population with no evidence of thyroid disease, the frequency of positive tests was very low in young people and increased to 23% in people older than 60. In 64 patients with no evidence of residual or metastasic thyroid tissue after surgery and radioiodine, initially positive antibody titres became negative in 54.6%, decreased in 32.8%, did not change in 3.1%, and increased in 9.3%. On the contrary, antibody titres of patients with persistent disease became undetectable in 8.3%, decreased in 16.6%, remained unchanged in 25%, and increased in 50%. The clinical course of differentiated thyroid cancer was unaffected by the presence of thyroid antibodies and no difference was found in the death rate between antibody-positive and antibody-negative patients (11.5% and 13.6%, respectively). In conclusion, our data indicate that: 1) autoimmune phenomena are not an infrequent finding in thyroid cancer; 2) as in non-malignant thyroid diseases, positive-antibody tests are more frequently observed in females than in males; 3) at variance with normal controls, no age-dependent increase in serum anti-thyroid antibodies was found in thyroid cancer; 4) the presence of metastatic thyroid tissue seems to be necessary to perpetuate the autoantibody synthesis, and 5) anti-thyroid autoantibodies are not a protective or worsening factor in the tumour outcome.

Abstract:

Abstract: Amiodarone, an iodine-rich drug, represents at the present, at least in Europe, one of the most common sources of iodine-induced thyroid dysfunction. The drug may induce both hypothyroidism and thyrotoxicosis. In spite of the large iodine intake occurring during amiodarone therapy, 131I thyroid uptake is detectable in patients with amiodarone-iodine-induced hypothyroidism, irrespective of the presence or absence of underlying thyroid disease. In contrast, in patients with amiodarone-iodine-induced thyrotoxicosis, 131I thyroid uptake is normal or even elevated in those with co-existent underlying thyroid disorders, whereas it is very low in those with an apparently normal thyroid gland. Perchlorate discharge test was performed in 8 patients with hypothyroidism and in 5 patients with hyperthyroidism induced by amiodarone: a positive test was found in all hypothyroid patients and a negative test in all hyperthyroid patients.

Abstract:

Abstract: Evidence has been accumulated that human thyroid microsomal/microvillar autoantigen (M) is expressed both in the cytoplasm and on the surface of thyroid follicular cells. The availability of this autoantigen to the immune system, possibly associated with abnormally expressed HLA-DR antigens may be relevant both to the triggering and to maintenance of thyroid autoimmune reactions. Preliminary biochemical characterization of M suggested that it was a glycoprotein with a mol. wt. of about 100-110 kD. recent studies carried out in our laboratories taking advantage of monoclonal antibodies provided evidence that the structure presently referred as M-Ag is represented by thyroid peroxidase (TPO). The identity between TPO and M is further supported by four-layer immunofluorescence analysis showing a complete overlap of the two antigens both in the surface and in the cytoplasm of thyroid cells and by the observation that the expression of M and TPO is similarly modulated by TSH, possibly through a cAMP-dependent mechanism.

Abstract:

Abstract: Amiodarone, a iodine-rich drug widely used in the treatment of tachyarrhythmias, represents one of the most common sources of iodine-induced thyrotoxicosis. The data concerning 58 patients with amiodarone-iodine-induced thyrotoxicosis (AIIT) were analyzed in the present study. Prevalence of AIIT was higher in males than in females (M/F = 1.23/l). Thyrotoxicosis occurred either during treatment with or at various intervals after withdrawal of amiodarone. AIIT developed not only in patients with underlying thyroid disorders, but also in subjects with apparently normal thyroid gland. Classical symptoms of thyrotoxicosis were often lacking, the main clinical feature being a worsening of cardiac disorders. Biochemical diagnosis of AIIT was established by the finding of elevated serum total and free triiodothyronine levels, since elevated serum total and free thyroxine could be found also in euthyroid amiodarone-treated subjects. Twenty-four-hour thyroid radioiodine uptake was very low or undetectable in AIIT patients with apparently normal thyroid glands, while it was inappropriately elevated in patients with underlying thyroid disorders, despite iodine contamination. The role of autoimmune phenomena in the pathogenesis of AIIT appeared to be limited, because circulating thyroid autoantibodies were undetectable in AIIT patients without underlying thyroid disorders or with nodular goiter. Conversely, humoral features of thyroid autoimmunity were mostly found in AIIT patients with diffuse goiter. Treatment of AIIT appeared to be a difficult challenge. Among the 11 patients given no treatment, thyrotoxicosis spontaneously subsided in the 5 patients with apparently normal thyroid gland, whereas the 6 patients with nodular or diffuse goiter were still hyperthyroid 6-9 months after discontinuation of the drug. The administration of high doses (40 mg/day) of methimazole alone proved to be ineffective in most (14/16) patients given this treatment. Twenty-seven patients were treated by methimazole combined with potassium perchlorate (1 g/day). With one exception, euthyroidism was restored within 15-90 days in all cases with underlying thyroid abnormalities, and within 6-55 days in subjects with apparently normal thyroid gland. Thus, the combined treatment appears to be the most effective one, but, due to the potential toxicity of potassium perchlorate, it should be reserved to patients with severe thyrotoxicosis and should be carefully monitored.

Abstract: T lymphocytes from thyroid infiltrate and peripheral blood (PB) of four patients with Hashimoto's thyroiditis (HT) were analysed at clonal level for their ability to secrete interleukin 2 (IL-2) and gamma-interferon (gamma-IFN). As controls, T cell clones from PB of four normal donors and from spleen of two trauma victims were used. While no abnormality was found in the capacity to produce IL-2, the proportion of gamma-IFN-producing (IFN-P) T cell clones derived from HT infiltrates was significantly higher (P less than 0.0005) than that of IFN-P clones derived from normal or patient PB. Most of CD4+ and CD8+ IFN-P clones from thyroid infiltrates, as well as a proportion of CD4+ PB-derived clones of patients with HT, released higher amounts of gamma-IFN than control clones. A relationship could be demonstrated between high gamma-IFN production and natural killer (NK) activity in T cell clones from thyroid and PB of HT patients. In fact, the percentage of IFN-P clones with NK potential (NK+) was remarkably higher (P less than 0.0005) in thyroid infiltrates than in normal spleen or PB. The proportion of IFN-P NK+ clones from patient PB was also significantly increased (P less than 0.02) but, unlike thyroid-derived clones in which the majority of IFN-P NK+ clones were CD8+, most PB-derived IFN-P NK+ clones from the same patients expressed the CD4+ phenotype. Almost all thyroid NK+ clones could be triggered to produce more gamma-IFN, while gamma-IFN synthesis by NK-negative thyroid clones was comparable to that of control clones. In view of the multiple effects ascribed to gamma-IFN in the cascade of events leading to immune responses, the abnormal potential to gamma-IFN secretion shown by intrathyroidal T lymphocytes may be of importance in the pathogenesis of autoimmune thyroiditis.

Abstract: Recent evidence indicates that human thyroid peroxidase (TPO) has most of the characteristics of the thyroid microsomal antigen. The question of whether TPO accounts for part or all of the antigenic activity recognized by circulating anti-microsomal antigen autoantibody (anti-M Ab) remains to be determined. The availability of an anti-TPO monoclonal antibody and of a highly purified TPO preparation allowed the development of specific and sensitive radioassays for anti-TPO autoantibody (anti-TPO Ab). In this study we compared anti-M Ab and anti-TPO Ab levels in serum from 128 subjects, including patients with Hashimoto's thyroiditis (n = 31), idiopathic myxedema (n = 11), hyperthyroid Graves' disease (n = 45), miscellaneous nonautoimmune thyroid disorders (n = 9), and normal subjects (n = 32). Anti-M Ab and anti-TPO Ab were measured by radioimmunological methods employing two different assay designs: 1) competitive radioassay (CR), based on the inhibition of radioiodinated antibody binding to human thyroid microsomes coated on microtiter wells, using a) [125I]immunoglobulin G (IgG) containing a high anti-M Ab titer (for anti-M Ab determinations), or b) [125I]anti-TPO monoclonal antibody (for anti-TPO Ab); and 2) sandwich immunoradiometric assay (IRMA) using microtiter wells coated with thyroid microsomes (for anti-M Ab determinations) or immunoaffinity-purified TPO (for anti-TPO Ab determinations) and [125I]anti-human IgG antibody. Anti-M Ab also was measured by passive hemagglutination. Anti-M Ab titers by PH closely correlated with anti-TPO Ab levels whether assayed by IRMA (r = 0.905; P less than 0.00001) or CR (r = 0.922; P less than 0.00001). Even closer correlations were found when anti-M Ab and anti-TPO Ab both were measured by the same type of radioassay procedure (IRMA, r = 0.945 and P less than 0.00001; CR, r = 0.957 and P less than 0.00001). No differences in the correlation between anti-M Ab and anti-TPO Ab results were found when the data in patients with different autoimmune thyroid disorders were analyzed separately. Further and more direct evidence for the identity of anti-M Ab and anti-TPO Ab was provided by the ability of purified TPO to completely inhibit the binding to thyroid microsomes of radioiodinated IgG preparations containing high anti-M Ab titers. In conclusion, our results provide strong support for the concept that TPO accounts for virtually all of the antigenic determinants reacting with the autoantibodies commonly termed anti-M antibodies.(ABSTRACT TRUNCATED AT 400 WORDS)

Abstract: Amiodarone, an iodine-rich drug widely used for the treatment of cardiac tachyarrhythmias, may induce either hyperthyroidism or hypothyroidism. Of 467 patients chronically treated with this drug referred to our institution, amiodarone iodine-induced hypothyroidism (AIIH) developed in 28 patients (6%). AIIH patients were subdivided into two groups according to the presence (group A) or absence (group B) of underlying thyroid abnormalities. Thyroid autoantibodies were present in 10 of 19 patients from group A and 0 of 9 patients from group B. The thyroid 24-h radioiodine uptake (RAIU) was evaluated in 15 patients: low values (less than 4%) were found in three patients and detectable values (7-50%) were observed in 12. Perchlorate discharge tests were positive in all four patients tested. Follow-up data were available in 20 patients (16 in group A and four in group B). Hypothyroidism was transient in 12 (60%) and persistent for several months after amiodarone withdrawal in eight (40%). While all patients in group B had transient hypothyroidism, 50% of patients with underlying thyroid abnormalities (group A) had persistent hypothyroidism. Thyroid autoantibodies were found in seven of eight patients with persistent hypothyroidism and in only three of 12 patients with transient hypothyroidism. Conversely, seven of 10 patients with positive thyroid autoantibodies had persistent hypothyroidism and 9 of 10 patients with undetectable thyroid autoantibodies had transient hypothyroidism. These data indicate that: (i) AIIH may develop in patients with or without underlying thyroid abnormalities; (ii) RAIU is inappropriately elevated in many patients with AIIH; (iii) intrathyroidal iodine is not organified; (iv) serum thyroid autoantibodies represent a risk factor for the development of AIIH; (v) AIIH spontaneously remits after amiodarone withdrawal in patients without thyroid abnormalities, but may persist in patients with concomitant thyroid disorders, especially those with circulating thyroid autoantibodies.

Abstract: Experimental and clinical evidence indicates that thymic endocrine function is under neuroendocrine control. Recently, a positive correlation was found between plasma thymulin (a major endocrine product of thymus) and serum thyroid hormone concentrations. Low serum thyroid hormone concentrations are frequently found in premature newborn infants. In this study we measured plasma thymulin by bioassay and serum T3 and T4 in a series of healthy fullterm newborns and in premature infants with various disorders. The study subjects were 26 healthy fullterm infants, 23 fullterm small for gestational age infants, 30 preterm appropriate for gestational age (AGA) infants, 22 preterm small for gestational age infants and 30 infants with respiratory distress syndrome, of whom 15 were fullterm and 15 were preterm AGA. Blood samples were obtained 3, 5, 10, 20, and 40 days after delivery. In the healthy fullterm infants plasma thymulin concentrations were low during the first days of life and subsequently increased, reaching normal values for children aged 1-12 months by the 10th day after birth. Persistently low plasma thymulin and serum T3 levels were found in the majority of infants with pathological conditions; the lowest values for both hormones were found in infants with respiratory distress syndrome. A highly significant positive correlation was present in all groups between mean plasma thymulin and serum T3, but not T4. Short term T3 administration in 6 additional preterm AGA infants caused a significant increase in plasma thymulin titers compared to those in 6 untreated infants. We conclude that plasma thymulin is decreased in premature newborns with the low T3 syndrome and that this abnormality may be reversed by administration of T3. These findings indicate that thymic endocrine activity is modulated by thyroid function in early postnatal life.

Abstract: Eighty consecutive patients with typical subacute thyroiditis were evaluated. Sex distribution showed a higher incidence in females (F/M 3.2/1), with a mean age of 44 yr. In the majority of patients (51/80 = 66%) the onset of the disease was between June and September (46% in July and August). The remaining cases were distributed in the other months without a clear monthly prevalence. These results indicate that the seasonal distribution of subacute thyroiditis is almost superimposable to that of established infections due to some enteroviruses (Echovirus, Coxsackie A and B viruses), suggesting that summer enterovirus infections may be responsible for a large proportion of cases of subacute thyroiditis.

Abstract: T Lymphocytes from thyroid infiltrates and peripheral blood (PB) of 3 patients with Hashimoto's thyroiditis (HT) were cloned using a microculture system previously shown to allow the clonal expansion of virtually all PB T lymphocytes from normal individuals. The phenotypic and functional features of a total number of 153 clones from thyroid infiltrates and 206 clones from PB were examined and compared with those of 272 clones derived from normal PB and spleens. The majority of clones derived from thyroid infiltrates of patients with HT had the cytotoxic/suppressor (T8+) phenotype, whereas the majority of clones from PB expressed the helper/inducer (T4+) phenotype. In addition, a consistent proportion (25%) of clones derived from PB of one patient had a phenotype (T3+T4-T8-) that was only occasionally found on clones obtained from PB or spleens of normal subjects. Most clones derived from both PB and thyroid infiltrates of the patients with HT had cytolytic activity, assessed by a lectin-dependent cytolytic assay against the murine P815 tumor cell line. The high frequency of cytotoxic T cells in thyroid infiltrates was related to the increased proportion of T8+ cells, whereas enhanced percentages of cytotoxic cell precursors with T4+ and T3+T4-T8- phenotypes primarily accounted for the high frequency of cytolytic T cells in the PB of the same patients. Many cytolytic T cell clones derived from thyroid infiltrates also had natural killer activity against human K562 and MOLT-4 target cells. These data provide the first functional analysis of T lymphocytes infiltrating the thyroid gland in patients with HT and suggest that the high proportions of cytolytic T cell precursors found in both thyroid infiltrates and PB of these patients may be of importance in determining the tissue damage in thyroid autoimmune disease.

Abstract: The thymus produces humoral factors that induce proliferation and differentiation of T-cells, which are responsible for cell-mediated immunity. Recent data in animals suggest that such thymic hormone activity is modulated by the neuroendocrine network and, in particular, by thyroid hormones, but no information is presently available in humans. To study this question, we measured the circulating thymic factor called thymulin (Zn-FTS) in hyperthyroid and hypothyroid patients. Thymulin levels were higher in hyperthyroid patients than in normal subjects, whereas hypothyroid patients had lower thymulin levels than normal subjects. A significant correlation was found between circulating thymulin and serum T4 and T3 levels. Thymulin changes could be reversed by appropriate treatment in both groups of patients. Recent data indicate that zinc is required to confer biological activity on thymic hormone molecules. This raised the question of whether the influence of thyroid status on thymulin activity could be mediated by changes in serum zinc concentrations. No support for such an explanation was obtained by thymulin measurements by a modified bioassay using an optimal zinc concentration in the assay system. In conclusion, thyroid status modulates thymic endocrine function in humans. Whether and to what extent such modulation is relevant to the function of the immune system remain to be established.

Abstract: High proportions of T8+ cells with inverted T4/T8 ratio were found in freshly isolated thyroid lymphocytes from patients with Hashimoto's thyroiditis. In addition, about one third of thyroid infiltrating cells expressed the TAC antigen, whereas in patient peripheral blood (PB) or normal lymphocytes from PB or lymphoid organs the percentage of TAC-positive cells was consistently lower than 10%. Following negative selection with OKT4 or OKT8 monoclonal antibodies and complement, TAC+ T cells were enriched in the T8+ cell population. Thyroid infiltrating T cells from two patients underwent two different cloning procedures. In the first, single T cells were initially activated with phytohaemagglutinin (PHA) and interleukin 2 (IL-2), in the other with recombinant IL-2 (rIL-2) alone. The majority of T cell clones obtained by initial PHA-stimulation (55-65%) had the T8+ phenotype, but the frequency of T8+ clones obtained by stimulating T cells with rIL-2 alone was even higher (78 & 71%, respectively). The majority of T8+ clones elicited by PHA (35/37 & 36/38) and all the T8+ clones (36/36 & 22/22) obtained from thyroid infiltrates with initial stimulation by rIL-2 displayed cytolytic activity. Most of cytolytic T8+ clones obtained from thyroid infiltrates with both cloning procedures, displayed NK activity against human K562 and MOLT-4 target cells, but not against a NK-resistant target, such as Raji cells. These data suggest that in Hashimoto's disease a considerable proportion of thyroid infiltrating T cells are in vivo activated T8+ cytolytic T cells with NK activity, which may be of importance in determining or maintaining the tissue damage of the target gland.

Abstract: Hypothyroidism is often observed after radioiodine treatment in Graves' disease, but it is considered a rare complication in single hyperfunctioning thyroid nodule ('hot' nodule). This concept has been recently challenged, but the available data are conflicting. In the present study we therefore assessed the development of permanent hypothyroidism in 126 patients with thyroid hot nodule treated with 131I (180 muCi/g of estimated nodule weight, total dose 5.5-28.9 mCi). Follow-up ranged between 1 to 11 years. Hypothyroidism was observed in 5 (4%) patients, corresponding to a cumulative incidence by life-table analysis of 4.8% ten years after treatment. No relationship was found between the development of hypothyroidism and the size of the nodule or the total amount of administered dose. Fifty-six patients with euthyroid hot nodule at the time of treatment had higher cumulative incidence of hypothyroidism after 10 years (9.7%) than those with toxic adenoma (1.5%) (0.1 greater than P greater than 0.05 by logrank test). When the patients were analyzed according to the presence or absence of serum antithyroglobulin and/or antithyroid microsomal autoantibodies, the prevalence of hypothyroidism after 131I treatment was higher (4/25 = 16%) in patients with significant serum antibody titres (greater than or equal to 1/400 by passive haemagglutination), when compared to that observed in subjects with negative antibody tests (1/101 = 1.0%). Life-table analysis showed in antibody positive patients a cumulative incidence of hypothyroidism after 10 years of 18.0% vs 1.4% in antibody negative patients (P less than 0.001 by logrank test).(ABSTRACT TRUNCATED AT 250 WORDS)

Abstract: We studied the effect of potassium perchlorate (KClO4) in patients with hypothyroidism due to amiodarone. The short term administration of KClO4 to six such patients led to prompt restoration of euthyroidism, while the three untreated patients remained hypothyroid for 2-6 months. Since KClO4 inhibits thyroid iodide transport, thereby blocking further entrance of iodide into the thyroid and decreasing intrathyroidal iodide content, amiodarone-associated hypothyroidism is probably secondary to the inhibitory effect of excess intrathyroidal iodine on thyroid hormone synthesis.

Abstract: Thyroid microsomal (MAb) and thyroglobulin (TgAb) antibodies were sequentially measured by sensitive and quantitative radioassays in 17 patients with goitrous Hashimoto's thyroiditis (9 hypothyroid, 8 euthyroid) and in 19 patients with idiopathic myxedema before and at various time intervals up to 24-48 months after the institution of L-thyroxine therapy. Thyroid antibodies were also determined in 5 euthyroid subjects with Hashimoto's thyroiditis maintained without treatment for a similar period. During L-thyroxine administration a reduction of MAb with respect to the pretreatment level was found in 6 of the 9 (67%) hypothyroid patients with Hashimoto's thyroiditis and in 16 of the 19 (84%) patients with idiopathic myxedema. The decrease of MAb was highly significant in both groups (p less than 0.001 and p less than 0.0001, respectively). A fall of TgAb occurred in 2 of the 3 patients (75%) with hypothyroid Hashimoto's thyroiditis and in 9 of the 10 (90%, p less than 0.001) patients with idiopathic myxedema having abnormally elevated pretreatment TgAB levels. No consistent pattern of MAb and TgAb changes was observed in the euthyroid subjects with Hashimoto's thyroiditis, whether treated or untreated. In the hypothyroid patients with Hashimoto's thyroiditis a significant association was found between the decrease of MAb and the reduction of goiter size (p less than 0.05) occurring during L-thyroxine administration. Moreover, the decrease of MAb and TgAb in idiopathic myxedema was greater (p less than 0.05) in the patients with normalized serum TSH (less than or equal to 4 microU/ml) than in those showing only a partial reduction of serum TSH (greater than 4 microU/ml) under L-thyroxine.(ABSTRACT TRUNCATED AT 250 WORDS)

Abstract: Amiodarone iodine induced thyrotoxicosis occurs frequently in patients residing in areas of mild iodine deficiency and in patients with preexisting goiter. Drug therapy of the hyperthyroidism is often unsuccessful. Twenty-three patients with amiodarone induced thyrotoxicosis were either not treated, treated with 40 mg methimazole daily or with methimazole and 1 gm potassium perchlorate daily for up to 40 days and then with methimazole alone. Thyrotoxicosis was more likely to spontaneously remit in patients without goiter. Therapy with methimazole alone was unsuccessful in inducing euthyroidism in 5 patients with goiter. However, combined therapy with methimazole and potassium perchlorate rapidly alleviated hyperthyroidism in almost all patients with goiter. This drug combination is successful because perchlorate inhibits the active transport of iodine into the thyroid and methimazole blocks the intrathyroidal synthesis of thyroid hormones.

Abstract: The rare event of a single cutaneous metastasis occurred in a 37-year-old white man two years after a subtotal thyroidectomy for sporadic medullary carcinoma is reported. The endocrine nature of the tumor is revealed by the ultrastructural study, and the type of secretion by the biochemical assay of calcitonin (CT) in the serum and in the tumor tissue extract and by the PAP (peroxidase-anti-peroxidase) technique with anti-CT antibodies on paraffin sections. The cytological and histological findings are described. Some peculiar ultrastructural aspects are presented in details. The fact that the patient received a course of Rx therapy (3,000 rads) on the neck for cervical syringomyelia at the age of 20 years is stressed.

Abstract: The in vitro synthesis of antithyroglobulin (anti-Tg) and antithyroid microsomal (anti-M) autoantibodies by peripheral blood mononuclear cells (MNC) from patients with autoimmune thyroid diseases was investigated using sensitive immunoradiometric assays. Cultures were carried out in the presence or in the absence of pokeweed mitogen (PWM). Thyroid autoantibodies were undetectable in supernatants of MNC cultures from 9 normal subjects. Supernatants of MNC cultured without PWM had detectable levels of anti-Tg and anti-M in 5 (19.3%) and in 2 (7.7%) of 26 patients with autoimmune thyroid diseases, respectively. In the presence of PWM, a marked increment in the antibody concentrations occurred in all but 1 of these cultures, and the number of positive cultures increased to 13 (50.1%) for anti-Tg and to 15 (57.7%) for anti-M. Studies of MNC fractions depleted of T lymphocytes (non-T cells) were carried out on selected patients showing antibody synthesis only after PWM stimulation. Autoantibody production was not found with non-T cells, but the effect of the mitogen was restored by readdition of T cells. Irradiation (1000 rad) of T cells before coculturing significantly enhanced autoantibody production. With this model no significant functional difference was found between autologous and allogenic T cells from thyroid autoimmune disease patients or from normal subjects. The cells involved in PWM-driven thyroid autoantibody synthesis, as defined by depletion studies, were lymphocytes bearing DR antigens and surface immunoglobulin G (IgG) without detectable surface immunoglobulin M (IgM). Depletion from MNC suspensions of Tg-binding cells abolished PWM-stimulated anti-Tg production, but did not alter the synthesis of anti-M. Further studies were carried out on MNC from a single patient with Hashimoto's thyroiditis, whose non-T cells consistently produced large amounts of anti-M and total IgG in the absence of PWM. The addition of PWM to these unfractionated MNC slightly increased the production of anti-M, but inhibited antibody synthesis after depletion of T lymphocytes. Interestingly, the addition of autologous T lymphocytes to non-T cells inhibited the spontaneous synthesis of anti-M. These data indicate that in vitro synthesis of anti-Tg and anti-M by MNC may be frequently induced by stimulation with PWM in patients with thyroid autoimmune disorders. PWM-stimulated synthesis of thyroid autoantibodies appears to be T-cell dependent and modulated by radiosensitive T lymphocytes. The cells responsible for PWM-dependent thyroid autoantibody synthesis are B lymphocytes with surface membrane IgG and have receptors specific for the autoantigen.(ABSTRACT TRUNCATED AT 400 WORDS)

Abstract: We recently described a solid phase immunoradiometric assay (IRMA) for anti-thyroglobulin and anti-thyroid microsomal antibodies. In the present study a similar IRMA for gastric parietal cell antibodies (PCA) has been developed. Samples to be tested are incubated within wells of polyvinyl microtitre plates coated with solubilized gastric microsomal antigen. After removal of unbound material, PCA is detected by adding purified 125I-anti-human IgG antibody. A good correlation was found with the results of PCA assays obtained by indirect immunofluorescence. In contrast, negative PCA by IRMA were consistently obtained in sera containing high titres of several other organ specific and non-organ specific autoantibodies. PCA determinations by IRMA were than carried out in a series of normal controls and patients with autoimmune or non-autoimmune thyroid disorders. Positive results were obtained in three of 70 (4.3%) apparently normal subjects, in 16 of 87 (18.4%) patients with Hashimoto's thyroiditis, in 10 of 48 (20.8%) with idiopathic myxoedema, in 25 of 95 (25.6%) with Graves' disease and in five of 64 (7.8%) with other non-autoimmune thyroid disorders. Preliminary results showed that quantitative measurements of PCA by IRMA could be performed using a serum containing high levels of PCA as standard reference. In conclusion, PCA may be easily and specifically detected using the same IRMA procedure previously developed for anti-thyroid antibodies. We therefore suggest that the present IRMA may be proposed as a general technique for the detection of different organ specific autoantibodies.

Abstract: A new sensitive, quantitative, and specific immunoradiometric assay (IRMA) for antithyroid microsomal (anti-M) antibody has been developed. Samples to be tested are incubated within wells of polyvinyl microtiter plates coated with solubilized thyroid microsomal antigen. After removal of unbound material, anti-M antibody is detected by adding purified [125I]antihuman immunoglobulin G (IgG) antibody. Using 1.0 microliter serum, anti-M antibody was found by IRMA in all of the patients with Hashimoto's thyroiditis or idiopathic myxedema (n = 19), in 86% of those with Graves' disease (n = 42), in 10.9% of subjects with other nonautoimmune thyroid disorders (n = 37), and in 8.4% of normal controls (n = 71). A good correlation was found with the results obtained in anti-M antibody tests by passive hemagglutination. Using larger volumes of serum (up to 100 microliters), anti-M antibody detectable by IRMA was found in some patients with Graves' disease and negative passive hemagglutination tests. Quantitative measurements of anti-M antibody by IRMA could be performed using a standard IgG preparation containing high levels of anti-M antibody. The minimal detectable amount ranged between 1-2 ng IgG, corresponding to a sensitivity 15-30 times greater than that of the competitive binding radioassay. We suggest that the present IRMA may be proposed as a general technique for the detection of different organ-specific autoantibodies.

Abstract: This paper describes a case of hypothyroidism in a patient with Waldenström's disease in which the evidence of thyroid failure was accompanied by an abnormal binding of thyroid hormones in the gamma-globulin fraction. A 68-yr-old patient with Waldenström's disease appeared to be hypothyroid by clinical and laboratory criteria. Serum TSH was elevated; serum T3 (measured by RIA) was low, while T4 levels were undetectable or very high according to the method used. Serum free thyroid hormones were in the hypothyroid range, and both antithyroglobulin and antimicrosomal thyroid antibodies were undetectable. The thyroid gland was normal at autopsy. Elevated binding of radiolabeled thyroid hormones by the patient's serum gamma-globulins was demonstrated by reverse flow electrophoresis and cellulose acetate electrophoresis. This binding could be inhibited by preincubation of serum samples with unlabeled T4 and T3, but not with human thyroglobulin, rT3, DIT, or MIT. Immunoprecipitation of the patient's serum incubated with [125I]T4 or [125I]T3 showed that 56% of T4 and 30% of T3, respectively, were precipitated using an antihuman immunoglobulin M(IGM) serum; only [125I]T4 was precipitable (22%) by the addition of an antihuman immunoglobulin G(IgG) serum. The binding of the thyroid hormones by IgM and IgG, which reduced T4 and T3 availability for their metabolic action at the tissue level, could have contributed to the clinical picture.

Abstract: The changes occurring in the levels of circulating thyroid microsomal antibody (M-Ab) and antithyroglobulin antibody (Tg-Ab) during antithyroid drug therapy were studied in 32 patients receiving methimazole for Graves' disease. M-Ab was determined by competitive binding radioassay and Tg-Ab by a sandwich radiometric method. Before treatment 25 subjects (78.1%) had abnormally elevated (greater than or equal to 75 U/ml) M-Ab levels. A more than 30% reduction of M-Ab concentration with respect to the pretreatment value was found in 16 (64.0%) of these patients within the first 3-5 months of therapy, in 23 (92.0%) within 8-11 months and in 21 (84.0%) at the end of treatment (16-18 months). No change was found in the 7 patients with initial M-Ab levels less than 75 U/ml. The reduction of M-Ab was more pronounced in the patients with good control of thyrotoxicosis than in those who were still hyperthyroid or were rendered hypothyroid during treatment. Twenty-three patients were followed after completion of the course of methimazole therapy, and 13 of them showed relapse of hyperthyroidism. A significant rise of M-Ab with respect to the values observed at the end of treatment occurred in all relapsing patients who had abnormally elevated M-Ab levels before therapy. With one exception, no M-Ab increase was found in the 10 nonrelapsing patients. However, no difference between relapsing and nonrelapsing patients was observed when the M-Ab changes occurring during treatment were considered. A similar trend during and after withdrawal of therapy was noted for Tg-Ab but, because of the relatively small percentage of positive subjects (25%), the results were less conclusive. The present data indicate that methimazole treatment induces a fall of thyroid antibodies in patients with Graves' disease, and that relapse of hyperthyroidism is associated with an increase of these antibodies. However, the antibody changes occurring during treatment showed no prognostic value in predicting the outcome of therapy.

Abstract: The effects of lithium carbonate on thyroid was evaluated in 40 consecutive psychiatric patients on long-term treatment with this drug. Five patients had clinical and/or biochemical hypothyroidism. Twenty four (60%) subjects showed goiter of different size, including very large glands. A very high prevalence of goiter (87%) was observed in the 15 patients coming from a moderate endemic area. A lower incidence of goiter (44%) was found in subjects coming from non endemic areas. Goiter was associated with significantly elevated serum thyroglobulin concentration similar to that reported in endemic or sporadic nontoxic goiter. None of 25 psychiatric patients not receiving lithium therapy was hypothyroid and only three (12.5%) of them showed a small size goiter. These data indicate a very high prevalence of thyroid enlargement in patients on lithium therapy and suggest the opportunity to institute a prophylactic thyroid hormone treatment at least in subjects coming from endemic areas.

Abstract: The presence of thyroid-stimulating immunoglobulins in patients with Graves' disease is well established. Considerable evidence has accumulated that these immunoglobulins are antibodies to a thyroid plasma membrane antigen whose precise nature remains to be identified. The question whether the antigen is related to the TSH receptor is still debated. The causative role of thyroid-stimulating immunoglobulins in the hyperthyroidism of Graves' disease is widely recognized. The use of human specific stimulation assays has circumvented the objection of the relatively low frequency of long-acting-thyroid-stimulator-(LATS)-positive patients. Individual variations in the thyroid response may account for the lack of correlation between the levels of thyroid-stimulating immunoglobulins and most parameters of thyroid function. In this respect, the interference of nonstimulatory thyroid antibodies and of other autoimmune mechanisms may be of importance. An important clinical implication of thyroid-stimulating immunoglobulin determinations is their value in predicting the relapse of hyperthyroidism in treated patients. This clinical application has been so far limited by the technical difficulties of the assays. This emphasizes the need for a simple and reliable test, which can be used for routine measurements of thyroid-stimulating immunoglobulins.

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Abstract: A newly developed sensitive and quantitative immunoradiometric assay (IRMA) for anti-thyroglobulin (anti-Tg) autoantibody is described. Serum samples to be tested are added to wells of polyvinyl microtiter plates coated with human thyroglobulin. After removal of the unbound material, anti-Tg antibody is determined by adding purified 125I-anti-human immunoglobulin G antibody. Using 1.0 microliter of serum anti-Tg antibody was detected in 81.2% of patients with Hashimoto's thyroiditis or idiopathic myxedema (n = 32), in 46.4% of those with Graves' disease (n = 28), in 11.9% of subjects with other thyroid disorders (n = 42) and in 4.2% of normal controls (n = 71). Similar percentages of positive tests were observed by passive hemagglutination (PH) and a good correlation was found between the antibody levels determined by the two techniques. Using larger amounts of serum (100 microliters) detectable anti-Tg antibody by IRMA was found in the majority of patients with thyroid autoimmune disorders who had negative PH tests. Quantitative measurements of anti-Tg antibody by IRMA could be obtained by using purified anti-Tg antibody as standard reference. The minimum detectable amount of anti-Tg antibody was 0.5 ng. The present method is proposed as a simple and convenient technique for quantitative measurement of any antibody, using wells coated with the appropriate antigen.

Abstract: Suppressor lymphocyte function was evaluated in control subjects and in patients with autoimmune thyroid disease, utilizing an assay in which indomethacin was added to lymphocyte cultures to inhibit prostaglandin-producing suppressor cells. This assay is based on the observation that the addition of indomethacin, a potent prostaglandin synthesis inhibitor, to phytohemagglutinin-stimulated peripheral blood lymphocytes should cause an increase in the incorporation of iododeoxyuridine in control subjects and a smaller increase in diseases with reduced prostaglandin-producing suppressor cells. The addition of indomethacin, 1 microgram/ml, stimulated iododeoxyuridine incorporation in phytohemagglutinin-stimulated cultures in control subjects to an index value of 1.43 (i.e., the increment in iododeoxyuridine incorporation with both indomethacin and phytohemagglutinin was 43% greater than the incorporation with phytohemagglutinin alone). The stimulation index was significantly lower in patients with Graves' disease who were toxic and untreated (1.18 +/- 0.25, mean +/- SD; P less than 0.003). Patients who were toxic while receiving antithyroid drugs or after radioiodine therapy or patients euthyroid after treatment had a mean stimulation index in the normal range, although the spread of data was very large in these groups. Responses in patients with Hashimoto's thyroiditis were also quite variable. The average response was 1.74 +/- 0.72, with 40% of the patients showing a high stimulation index. This study supports our previous investigations in which we used different assay systems for measuring suppressor-cell function in patients with thyroid autoimmune diseases and indicates that a defect in suppressor lymphocyte function is measureable by another technique. The abnormality persists in some cases after metabolic control has been achieved, but usually returns toward normal over months or years.

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Abstract: We describe a simple solid-phase radioimmunoassay (RIA) to detect IgG based on competitive binding between radiolabeled and unlabeled IgG for anti-IgG antibody physically adsorbed to the wells of polyvinyl microtiter plates. The assay is sensitive (1 ng), rapid, and is particularly suited for studies of in vitro IgG secretion by human peripheral blood lymphocytes, since such studies require large numbers of cultures. Conditions which permit measurement, by means of this assay, of helper and suppressor T cell effects on IgG production by human B cells in culture are described.

Abstract: The ability of detergents (Triton X-100 and deoxycholate), high ionic strength solution (3 M KC1), and proteolytic enzymes (papain and trypsin) to solubilize human thyroid microsomal antigen was studied. Antigenic activity released from thyroid microsomal preparation into the incubation mixture was separated by centrifugation at 143,000 x g for 90 min and measured using 125I-labeled human immunoglobulin G (IgG) with elevated antimicrosomal (anti-M) and undetectable anti-thyroglobulin antibodies (anti-M IgG). All solubilized materials were shown to bind [125I]anti-M IgG and to inhibit its binding to untreated thyroid microsomes. These effects were specific and dose related. Measurements of specific activity and total amount of solubilized antigen by an absorption technique showed that Triton X-100 was the most effective agent, followed by deoxycholate, papain, trypsin, and 3 M KC1 in decreasing order. Affinity chromatography with the deoxycholate-solubilized material coupled to Sepharose 4B resulted in a 15.6-fold purification of [125I]anti-M antibodies. The present results indicate that thyroid microsomal antigen may be solubilized by several agents and this can provide the basis for its identification and purification.

Abstract:

Abstract: Parallel measurements of circulating anti-thyroid microsomal (anti-M) antibodies by radioassay and haemagglutination were performed on subjects with or without thyroid disorders. Three-quarters (75.4%) of control subjects had undetectable antibody levels (less than 10 u/ml) by radioassay and only 3.1% had concentrations of greater than or equal to 75 u/ml. Abnormally elevated levels (greater than or equal to 75 u/ml) were found in most of the patients with Hashimoto's thyroiditis (94.1%) or idiopathic myxoedema (86.7%), in the majority (75.0%) of those with Graves' disease and only in a minority of those with other thyroid disorders. The percentage of positive sera by haemagglutination was very similar in all groups to that of abnormal values observed in the radioassay. Direct comparison of parallel tests on a total of 631 sera revealed a highly significant correlation (r = 0.91, P less than 0.001) between the two methods, but elevated antibody titres by haemagglutination were found in some sera with negative radioassays. All these sera were from a single patient with thyroid carcinoma associated with Hashimoto's thyroiditis and had elevated levels of anti-thyroglobulin (anti-Tg) antibodies. Evidence that such discrepancies were due to anti-Tg antibodies reacting with microsomal-bound Tg was provided by the demonstration that the haemagglutination produced by these sera could be completely inhibited by the addition of Tg. A similar inhibition was observed with two rabbit antisera to human Tg, but not with sera from patients with thyroid autoimmune disorders containing high levels of anti-microsomal anti-bodies.

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