Nuclear Medicine Unit, Medical-Surgical Department of Clinical Sciences, Technobiomedicine and Translational Medicine, Faculty of Medicine and Psychology, "Sapienza" University, S. Andrea Hospital, Via di Grottarossa 1035, 00189, Italy
Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Hanzeplein 1, PO BOX 30.001, 9700 RB Groningen, The Neyherlands
alberto.signore@uniroma1.it
Name, Title, Birth date (dt/mo/yr) ALBERTO SIGNORE, MD, PhD, 1 NOVEMBER 1959
Affiliation (City, State, Country) Nuclear Medicine Unit, Medical-Surgical Department of Clinical Sciences, Technobiomedicine and Translational Medicine, Faculty of Medicine and Psychology, "Sapienza" University, Rome, Italy. Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen,The Netherlands.
EDUCATION 2007 PhD at the University of Groningen, the Netherlands. 1991 Specialization in Nuclear Medicine, (full marks cum laude), University of Rome "La Sapienza", Italy. 1987 Specialization in Endocrinology (full marks cum laude), University of Rome "La Sapienza", Italy. 1984 University degree in Medicine & Surgery (full marks cum laude), University of Rome "La Sapienza", Italy.
PRESENT ACTIVITY Honorary Full Professor in Nuclear Medicine and Molecular Imaging, University Medical Center, Groningen, The Netherlands. Aggregated Professor in Nuclear Medicine, University of Rome "La Sapienza", Italy. Visiting Professor in Nuclear Medicine, University of Ghent, Belgium. Vice-director of the Specialization School in Nuclear Medicine of University of Rome "La Sapienza", Italy. Consultant of the International Atomic Energy Agency, Vienna. Consultant in Nuclear Medicine at Mayo Clinic, Rochester, USA. Co-promoter of the International Research Consortium IMITT. Management Committee member of the COST-BM0607 action of the European Community “Targeted Radionuclide Therapy” Secretary and Past-President of the International Society of Radiolabelled Blood Elements (ISORBE). Secretary and Past-President of the International Research Group in Immunoscintigraphy and Therapy (IRIST). Coordinator of the Task Group on “Inflammation-Infection-Imaging” of the European Association of Nuclear Medicine (EANM). National delegate for the Union of European Medical Schools (UEMS). Member of the Editorial Board of the QJNM&MI, NucMedCommun, EJNM&MI, JNM and other scientific journals.
SCIENTIFIC ACTIVITY Author of over 170 scientific publications in national and international journals (Total Impact Factor of about 400, H-index=22). Promoter of 9 PhD student’s thesis.
PROFESSIONAL EXPERIENCE 2002-2005 Professor of "Diagnostic imaging in Neurology and Psychiatry" at the 2nd School of Specialization in Psychiatry, University of Rome "La Sapienza" 2000-2005 Professor of "Theory of Tracers" at the School of Specialization in Nuclear Medicine, University of Rome "La Sapienza" 2000-2002 Professor of Nuclear Medicine at the 2nd School of Specialization in Endocrinology, University of Rome "La Sapienza" 2000 Appointed Official University Lecturer in the MED36 discipline per decree of the Rector of the University of Rome, "La Sapienza". 1998-2000 Professorship of “Immuno-haematology”, at the University of Urbino, High School for Biomedical Laboratory Technicians, Faculty of Pharmacy and Biology. 1994-1998 Professorship of “Immunological Techniques”, at the University of Urbino, High School for Biomedical Laboratory Technicians, Faculty of Pharmacy and Biology. 1991-present Lecturer and Medical Assistant - Nuclear Medicine Unit, Dept. of Clinical Sciences, University "La Sapienza", Rome, Italy 1991 Official medical position at the “Servizio Speciale Medicina Nucleare” of the II Clinica Medica, University of Rome “La Sapienza”, (Registrar). 1990 Tenured academic position at the University of Rome "La Sapienza", II Clinica Medica, (Lecturer).
NATIONAL AND INTERNATIONAL AWARDS AND HONORS 2004 Marie Curie Award of the EANM. 2003 Highlight lecture at the EANM congress in Amsterdam. 2002-2006 Secretary of the "International Research Group in Immunoscintigraphy and Immunotherapy” (IRIST). 2003-2004 President of the "International Research Group in Immunoscintigraphy and Immunotherapy” (IRIST). 2001-2005 Secretary of the "International Society of Radiolabelled Blood Elements" (ISORBE). President: Dr. M. Rodrigues 2000 Member of the COST B12 Working Group 3 "Radiolabelled Peptides" of the European Community. 1999-2001.1 President of the "International Society of Radiolabelled Blood Elements" (ISORBE). 1995-1997 Secretary of the "International Society of Radiolabelled Blood Elements" (ISORBE). President: Dr. J. Martin-Comin 1997 Award of the Italian Society of Endocrinology for distinguished research in the field of early diagnosis of organ specific autoimmune diseases 1994 “Masahiro Iio” Award of the World Federation of Nuclear Medicine and Biology, Sidney, Australia for the paper entitled “99mTc-interleukin-2 a new radiopharmaceutical for the in vivo detection of activated lymphocytes: bio-distribution in animals and normal subjects”, authors: Chianelli M, Signore A, Sobnak R, Fritzberg AR, Britton KE, Mather SJ. 1993 Award for the best scientific work at the "1st Congress of Italian association of Nuclear Medicine and Italian Society of Paediatrics" Ferrara, Italy 1990 Award of the Italian Society of Endocrinology for distinguished research in the field of early diagnosis of organ specific autoimmune diseases 1990 Award of the XIII Congress of the Italian Society of Diabetes, Pisa, Italy 1988-1990 Postdoctoral fellowship of the Juvenile Diabetes Foundation, USA 1987 International Award of the "Fourth Milano International Meeting on Diabetes", Milano, Italy 1986-1987 Renewal of above mentioned scholarship 1985-1986 Scholarship at the Institute Pasteur - Fondazione Cenci Bolognetti 1985 Scholarship at the Italian Centro Nazionale Ricerche (CNR) for the United Kingdom
Abstract: PURPOSE: It is known that major histocompatibility complex class II protein HLA-DR is highly expressed in B-cell lymphomas and in a variety of autoimmune and inflammatory diseases. Therefore, a radiolabelled fully humanized IgG4 monoclonal antibody (mAb) can provide useful prognostic and diagnostic information. Aims of the present study were to radiolabel an anti-HLA-DR mAb with technetium-99m and to evaluate its binding specificity, tissue distribution and targeting potential. PROCEDURES: For labelling, we compared a direct method, after 2-mercaptoethanol (2-ME) reduction of disulphide bonds, with a two-step labelling method, using a heterobifunctional succinimidyl-6-hydrazinonicotinate hydrochloride chelator. Several in vitro quality controls and in vivo experiments in mice were performed. RESULTS: We obtained highest labelling efficiency (LE, >98%) and specific activity (SA; 5,550 MBq/mg) via the direct method. In vitro quality control showed good stability, structural integrity and retention of the binding properties of the labelled mAb. The biodistribution in mice showed high and persistent uptake in spleen and suggests kidney and liver-mediated clearance pathways. In tumour targeting experiments, we observed high uptake in HLA-DR-positive xenografts compared to controls. In vivo binding was proportional to the number of injected cells. In the in vivo blocking assay, uptake of radiolabelled mAb was significantly decreased in mice pre-injected with 100-fold molar excess of unlabelled mAb. CONCLUSION: We efficiently labelled a humanized anti-HLA-DR mAb with (99m)Tc using a direct labelling method. Radiolabelled mAb binds to human HLA-DR antigens and therefore warrants further evaluation as a prognostic and diagnostic tool for patients with lymphoma or autoimmune diseases.
Abstract: BACKGROUND: Joint replacement surgery has been on the increase in recent decades and prosthesis infection remains the most critical complication. Many aspects of the primary prevention and clinical management of such prosthesis infections still need to be clarified. CONTROVERSIAL ISSUES: The aim of this GISIG (Gruppo Italiano di Studio sulle Infezioni Gravi) working group - a panel of multidisciplinary experts - was to define recommendations for the following controversial issues: (1) Is a conservative surgical approach for the management of prosthetic joint infections effective? (2) Is the one-stage or the two-stage revision for the management of prosthetic joint infections more effective? (3) What is the most effective treatment for the management of prosthetic joint infections due to methicillin-resistant staphylococci? Results are presented and discussed in detail. METHODS: A systematic literature search using the MEDLINE database for the period 1988 to 2008 of randomized controlled trials and/or non-randomized studies was performed. A matrix was created to extract evidence from original studies using the CONSORT method to evaluate randomized clinical trials and the Newcastle-Ottawa Quality Assessment Scale for case-control studies, longitudinal cohorts, and retrospective studies. The GRADE method for grading quality of evidence and strength of recommendation was applied.
Abstract: Inflammatory bowel diseases are represented by ulcerative colitis and Crohn's disease, both consisting of a chronic, uncontrolled inflammation of the intestinal mucosa of any part of the gastrointestinal tract with patchy or continuous inflammation. Ileo-colonoscopy is considered the current gold standard imaging technique for the diagnosis. However, as the majority of patients need a long-term follow-up it would be ideal to rely on a non-invasive technique with good compliance. This review focuses on nuclear medicine imaging techniques in Crohn's disease. Different scintigraphic methods of imaging cells involved in the pathogenesis are described. The radiopharmaceuticals can be divided into non-specific radiopharmaceuticals for inflammation and specific radiopharmaceuticals that directly image lymphocytes involved in the process. This non-invasive molecular imaging approach can be useful also because it images the small bowel or other areas--where colonoscopy is not useful-and that it may play a role for constant follow-up, because relapses are frequent. Finally, an update on other imaging modalities, and particularly MRI, in the evaluation of Crohn's disease activity, is provided. Although MRI cannot directly detect inflammatory cells, it has shown a high sensitivity in detecting the macroscopic signs of inflammation at the level of the intestinal wall affected by Crohn's disease and Ulcerative colitis. The current diagnostic value of MRI in the detection of inflamed bowel segment and in the assessment of CD activity, as well the potentials MR spectroscopy, MR diffusion imaging and MR molecular imaging, is briefly discussed. J. Cell. Physiol. (c) 2010 Wiley-Liss, Inc.
Abstract: INTRODUCTION: Interleukin-2 (IL-2) when radiolabelled with (99m)Tc has been proved useful in imaging the side of lymphocytic infiltration in patients with autoimmune disorders and plays a significant role as a T-cell imaging agent. However, the labelling procedures used so far appeared to be rather complex and laborious. The aim of present study was to develop an efficient procedure of (99m)Tc-labelling of recombinant human interleukin-2 (rhIL-2) via hydrazinonicotinamide (HYNIC) to develop a dry kit formulation. METHODS: Various molar ratios of rhIL-2/HYNIC (from 1:2 to 1:12) were used at the conjugation step. The conjugates were purified on a PD-10 column to remove the excess of unbound HYNIC, as well as of any aggregates. The final peptide concentration was quantified by the BCA method, and the number of HYNIC molecules incorporated into a rhIL-2 molecule was determined based on the reaction with 2-sulfobenzaldehyde. The (99m)Tc-labelling was optimized using various amounts of HYNIC-rhIL-2, (99m)Tc, SnCl(2), tricine and nicotinic acid (NA). Quality control included GF-HPLC, ITLC, SDS-PAGE and biological assay. Biodistribution studies were performed in Swiss mice and Wistar rats. RESULTS: Generally, the highest radiolabelling yields were achieved when the HYNIC-rhIL-2 conjugates of ca. 2-4 HYNIC molecule substitution ratios were used. The optimal pH of the reaction medium was found to be in the range of 6.5 to 7.0. GF-HPLC analysis indicated that monomer and aggregates of (99m)Tc-HYNIC-rhIL-2 are formed during radiolabelling. At optimized conditions of wet radiolabelling, the (99m)Tc-HYNIC-rhIL-2 monomer was obtained with radiochemical purity >99%, specific activity of ca. 4 GBq/mg rhIL-2 and overall yield of ca. 65%. The two-vial freeze-dried kit was prepared: the first vial contained 30 μg HYNIC-rhIL-2, co-ligands, buffer and antioxidant; the second vial contained tricine and SnCl(2). The monomer of (99m)Tc-HYNIC-rhIL-2 was obtained by gel chromatography on a PD-10 column. No differences between labelled and unlabelled IL2 in terms of biological activity were observed. CONCLUSIONS: Our study shows that rhIL-2 can be efficiently radiolabelled with (99m)Tc via HYNIC, with tricine and NA as co-ligands using a two-vial freeze-dried kit. This enables the preparation of sterile and ready-to-use (99m)Tc-HYNIC(tricine,NA)-rhIL-2 within 1 h.
Abstract: The closing of the last century opened a wide variety of approaches for inflammation imaging and treatment of patients with rheumatoid arthritis (RA). The introduction of biological therapies for the management of RA started a revolution in the therapeutic armamentarium with the development of several novel monoclonal antibodies (mAbs), which can be murine, chimeric, humanised and fully human antibodies. Monoclonal antibodies specifically bind to their target, which could be adhesion molecules, activation markers, antigens or receptors, to interfere with specific inflammation pathways at the molecular level, leading to immune-modulation of the underlying pathogenic process. These new generation of mAbs can also be radiolabelled by using direct or indirect method, with a variety of nuclides, depending upon the specific diagnostic application. For studying rheumatoid arthritis patients, several monoclonal antibodies and their fragments, including anti-TNF-alpha, anti-CD20, anti-CD3, anti-CD4 and anti-E-selectin antibody, have been radiolabelled mainly with (99m)Tc or (111)In. Scintigraphy with these radiolabelled antibodies may offer an exciting possibility for the study of RA patients and holds two types of information: (1) it allows better staging of the disease and diagnosis of the state of activity by early detection of inflamed joints that might be difficult to assess; (2) it might provide a possibility to perform 'evidence-based biological therapy' of arthritis with a view to assessing whether an antibody will localise in an inflamed joint before using the same unlabelled antibody therapeutically. This might prove particularly important for the selection of patients to be treated since biological therapies can be associated with severe side-effects and are considerably expensive. This article reviews the use of radiolabelled mAbs in the study of RA with particular emphasis on the use of different radiolabelled monoclonal antibodies for therapy decision-making and follow-up.
Abstract: We describe here a protocol for labelling autologous white blood cells with (99m)Tc-HMPAO based on previously published consensus papers and guidelines. This protocol includes quality control and safety procedures and is in accordance with current European Union regulations and International Atomic Energy Agency recommendations.
Abstract: We describe here a protocol for labelling autologous white blood cells with (111)In-oxine based on previously published consensus papers and guidelines. This protocol includes quality control and safety procedures and is in accordance with current European Union regulations and International Atomic Energy Agency recommendations.
Abstract: Atherosclerosis is the major cause of cardiovascular disease, which still has the leading position in morbidity and mortality in the Western world. Many risk factors and pathobiological processes are acting together in the development of atherosclerosis. This leads to different remodelling stages (positive and negative) which are both associated with plaque physiology and clinical presentation. The different remodelling stages of atherosclerosis are explained with their clinical relevance. Recent advances in basic science have established that atherosclerosis is not only a lipid storage disease, but that also inflammation has a fundamental role in all stages of the disease. The molecular events leading to atherosclerosis will be extensively reviewed and described. Further on in this review different modalities and their role in the different stages of atherosclerosis will be discussed. Non-nuclear invasive imaging techniques (intravascular ultrasound, intravascular MRI, intracoronary angioscopy and intravascular optical coherence tomography) and non-nuclear non-invasive imaging techniques (ultrasound with Doppler flow, electron-bean computed tomography, coronary computed tomography angiography, MRI and coronary artery MR angiography) will be reviewed. After that we focus on nuclear imaging techniques for detecting atherosclerotic plaques, divided into three groups: atherosclerotic lesion components, inflammation and thrombosis. This emerging area of nuclear imaging techniques can provide measures of biological activity of atherosclerotic plaques, thereby improving the prediction of clinical events. As we will see in the future perspectives, at present, there is no special tracer that can be called the diagnostic tool to diagnose prospective stroke or infarction in patients. Nevertheless, we expect such a tracer to be developed in the next few years and maybe, theoretically, it could even be used for targeted therapy (in the form of a beta-emitter) to combat cardiovascular disease.
Abstract: Visilizumab is an IgG(2) humanized monoclonal antibody (mAb) characterized by non-FcgammaR binding and specific to the CD3 antigen, expressed on more than 95% of circulating resting T-lymphocytes and on activated T-lymphocytes homing in inflamed tissues. We hypothesized that the use of a radiolabeled anti-CD3 antibody might serve as a diagnostic tool for imaging T-cell traffic and lymphocytic infiltration of tissues and organs affected by autoimmune diseases. Here we describe the results of in vitro and animal experiments with (99m)Tc-succinimidyl-6-hydrazinonicotinate hydrochloride (SHNH)-visilizumab. METHODS: For mAb labeling, we used a 2-step method with a heterobifunctional linker SHNH. Several titrations were performed to obtain the best labeling efficiency. In vitro quality controls included stability assay, cysteine challenge, sodium dodecyl sulfate polyacrylamide gel electrophoresis, binding assay, and immunoreactivity assay. In vivo studies by high-resolution images were performed at 6 and 24 h after the injection of (99m)Tc-SHNH-visilizumab. These included cell-targeting experiments in BALB/c mice xenografted subcutaneously with an increasing number of HuT78 cells in the leg and displaced with an excess of cold antibody. We also studied irradiated severe combined immunodeficient (SCID) mice reconstituted with human peripheral blood mononuclear cells (hPBMCs) and injected with (99m)Tc-labeled visilizumab or control mAb. After dynamic imaging for 3 h, major organs were removed, counted, and processed for immunohistologic examination. RESULTS: Visilizumab was labeled with HYNIC with high labeling efficiency (>90%) and high specific activity (SA; 10,360-11,100 MBq/mg), with retained biochemical integrity and in vitro binding activity to CD3-positive cells. The in vivo targeting experiment showed a proportional increase of specific uptake with the number of injected cells, both at 6 and at 24 h, and the in vivo competition study demonstrated more than 60% decreased uptake after an excess of unlabeled antibody. In SCID mice, hPBMCs in different tissues were detected by (99m)Tc-labeled visilizumab and confirmed by histology. CONCLUSION: Visilizumab can be efficiently labeled with (99m)Tc with high efficiency and SA and could be a valuable tool for the study of human T-lymphocyte trafficking and lymphocytic infiltration of tissues and organs.
Abstract: OBJECTIVE: (a) To compare the efficacy of low-activity (2 GBq; 54 mCi) (131)I ablation using l-thyroxine withdrawal or rhTSH stimulation, and (b) to assess the influence of thyroid remnants volume on the ablation rate. DESIGN: Patients underwent neck ultrasound, (131)I neck scintigraphy and radioiodine uptake. Post-therapy whole body scan (WBS) was acquired after 4-6 days. Ablation was assessed after 6-12 months by WBS, Tg and TgAb following l-thyroxine withdrawal. METHODS: Group A: preparation by L-T(4) withdrawal (37 days); 21 patients received (131)I (2.02+/-0.22 GBq; 54.6+/-5.9 mCi) and on the day of treatment, TSH, Tg, TgAb were measured; Group B: stimulation by rhTSH; 21 patients received (131)I (1.97+/-0.18 GBq; 53.2+/-4.9 mCi) 24 h after the second injection of rhTSH (0.9 mg) and TSH, Tg and TgAb were measured after 2 days. RESULTS: At follow-up, 90.0% of patients from group A and 85.0% of patients from group B had Tg levels <1 ng/ml; no uptake was observed in 95.2% and in 90.5% of patients from group A or B respectively, with no statistical differences for both ablation criteria. Before (131)I treatment, small thyroid remnants (<1 ml) were detected by US in <25% of all patients. CONCLUSIONS: The use of rhTSH for the preparation of low-risk patients to ablation therapy with low activities of (131)I (2 GBq; 54 mCi) is safe and effective and avoids hypothyroidism. The presence of thyroid remnants smaller than 1 ml at US evaluation had no effect on the ablation rate.
Abstract: Neuroendocrine tumors (NETs) are relatively rare tumors, mainly originating from the digestive system, able to produce bioactive amines and hormones. NETs tend to be slow growing and are often diagnosed when metastatic. The localization of a NETs and the assessment of the extent of disease are crucial for management. Commonly used diagnostic techniques include morphological imaging (ultrasound, computerized tomography, magnetic resonance), and functional imaging (somatostatin receptor scintigraphy, positron emission tomography techniques). Treatment is multidisciplinary and should be individualized according to the tumor type, burden, and symptoms. Therapeutic tools include surgery, interventional radiology, and medical treatments such as somatostatin analogues, interferon, chemotherapy, new targeted drugs and peptide receptor radionuclide therapy (PRRT) with radiolabeled somatostatin analogues. NETs usually over-express somatostatin receptors, thus enabling the therapeutic use of somatostatin analogues, one of the basic tools, able to reduce signs and symptoms of hormone hypersecretion, improve quality of life, and slow tumor growth. PRRT with somatostatin analogues 90Y-DOTATOC and 177Lu-DOTATATE has been explored in NETs for more than a decade. Present knowledge and clinical studies indicate that it is possible to deliver high-absorbed doses to tumors expressing sst2 receptors, with partial and complete objective responses in up to 30% of patients. Side effects, involving the kidney and the bone marrow, are mild if adequate renal protection is used. Moreover, a consistent survival benefit is reported. As NETs may also express cholecystokinin 2, bombesin, neuropeptide Y or vasoactive intestinal peptide receptors even simultaneously, the potential availability and biological stability of radio-analogues will improve the multireceptor targeting of NETs.
Abstract: INTRODUCTION: We have previously described the labeling of interleukin-2 (IL2) with (123)I and (99m)Tc-N(3)S. Both radiopharmaceuticals were successfully applied in humans to image several inflammatory lesions and autoimmune diseases characterized by tissue infiltrating lymphocytes expressing the IL2 receptor (CD25). However, both radiopharmaceuticals had some specific disadvantages, such as cost and time of synthesis. MATERIALS AND METHODS: Here, we describe a new improved method for labeling interleukin-2 with (99m)Tc using HYNIC-NHS and tricine as coligand. Several optimizations of reagent concentrations and labeling conditions were performed in order to standardize the procedure. After labeling, IL2 was purified by tC2 reverse-phase chromatography and tested in vitro and in vivo, in mice and in a normal volunteer. Results showed that this labeling procedure is cheap, fast, reliable, and reproducible, leading to a product with high specific activity (153 microCi/microg), high stability and capable of binding in vitro to CD25 positive cells. In vivo biodistribution in mice and human volunteer did not show any significant different from (99m)Tc-N(3)S-IL2. CONCLUSION: In conclusion, the optimization of (99m)Tc-HYNIC-IL2 has a great advantage in terms of cost and time of production and a simple kit formulation can be considered for routine application to study patients affected by autoimmune diseases, graft rejection, or other chronic inflammatory disorders.
Abstract: BACKGROUND: The appearance of natural suppressor cells and circulating endothelial progenitor cells in tumour tissue has been associated with myelopoetic stimulation by growth factors that may increase fluorodeoxyglucose (FDG) uptake by the bone marrow and high FDG uptake by bone marrow in patients suffering from human malignancies is a not uncommon finding. METHODS: This study looked at the relationship between bone marrow FDG uptake, biochemical (Hb level, RBC count, WBC count and platelet count), clinical and radiological findings and outcome in a series of 35 patients suffering from squamous cell carcinoma of the head and neck (SCCHN), consecutively referred for FDG PET as part of their routine staging procedure. RESULTS AND CONCLUSION: In SCCHN, mean FDG standardized uptake values (SUVs) of the primary tumour correlate significantly with blood WBC count (r=0.44; P=0.011, Bonferroni corrected P=0.04) and mean FDG SUVs of bone marrow are significantly correlated to the maximum FDG SUVs of the primary tumour (r=0.523; P=0.002). Finally, FDG uptake by the bone marrow is related to disease-free and overall survival. These findings warrant confirmation in a larger patient series.
Abstract: CD4(+) CD25(+) T-cells play a central role in initiating and maintaining anticancer immune response. On the other hand, CD25(+) is also expressed on tumor cells, the meaning of which is currently unclear. Therefore, this study was designed to determine the prognostic value of the presence of CD4(+) CD25(+) T-cells in squamous-cell carcinoma of the head and neck (SCCHN) and of CD25 on SCCHN tumor cells. Thirty-five (35) patients diagnosed with a primary untreated SCCHN were included in this study. Instantly snap-frozen resection or biopsy specimens were analyzed by immunohistochemistry. Histologic results obtained were related to overall, disease-free survival. On univariate analysis, both lymph-node status and the number of CD25(+) lymphocytes were associated with disease-free survival (p=0.039 and 0.04). On multivariate analysis, only the number of CD25(+) lymphocytes showed an association with disease-free survival (p=0.036), whereas both factors showed an independent association with overall survival (p=0.007 and 0.003). Contrarywise, the CD25 expression on SCCHN tumor cells was not associated with disease-free survival nor with overall survival. The presence of a high number of SCCHN-infiltrating CD4(+) CD25(+) lymphocytes is associated with a good prognosis in SCCHN patients. Contrarywise, the CD25 expression on SCCHN tumor cells is not associated with a prognosis in SCCHN patients, and its role and meaning remains to be elucidated.
Abstract: The current gold standard for imaging infection is radiolabeled white blood cells. For reasons of safety, simplicity and cost, it would be desirable to have a receptor-specific ligand that could be used for imaging infection and that would allow a differential diagnosis between sterile and septic inflammatory processes. Ligands tested for this purpose include labeled peptides ((99m)Tc-labeled f-Met-Leu-Phe, (123)I-IL-1ra, (99m)Tc-IL-8, (99m)Tc-P483H, (99m)Tc-P1827DS, (99m)Tc-C5a-des-Arg, (99m)Tc-RP517, (11)In-DPC11870-11), human polyclonal antibodies, monoclonal antibodies, antibody fragments, antimicrobial agents (ciprofloxacin, sparfloxacin, ceftizoxime, isoniazid, ethambutol, fluconazole, all labeled with (99m)Tc), antimicrobial peptides and bacteriophages. Radiolabeled antibodies represent a valid alternative to labeled white blood cells under specific conditions and indications. Radiolabeled antibiotics and antimicrobial peptides are promising candidates for an infection-specific radiopharmaceutical. However, at present we still need to investigate many basic aspects to better understand the mechanisms of binding and accumulation of this class of radiopharmaceuticals to bacteria.
Abstract: Radiolabelled peptides and monoclonal antibodies are an emerging class of radiopharmaceuticals for imaging inflammation with clinical implications for several chronic inflammatory disorders for diagnosis, therapy decision making and follow up. In the last decades, a number of novel monoclonal antibodies and peptides have been introduced for the treatment of different inflammatory disorders and also labelled with a variety of radionuclides depending upon the specific applications, diagnostic or therapeutic, by using direct or indirect methods. These radiopharmaceuticals bind to their targets with high affinity and specificity and therefore have an excellent diagnostic potential for the imaging of patients with chronic inflammatory diseases. In this review article we describe the characteristics of peptides, cytokines and monoclonal antibodies with a particular emphasis on their role in therapy decision making and follow up in different inflammatory diseases.
Abstract: PURPOSE: Radiolabelled interleukin-2 is a radiopharmaceutical used for the study of chronic inflammatory processes. (123)I-labelled interleukin-2 has successfully been used in a large number of patients affected by several immune-mediated diseases. (123)I, however, is expensive and not readily available. We have, therefore, developed a method for labelling interleukin-2 with (99m)Tc to high specific activity based on the use of an N(3)S bifunctional chelating agent. In this paper, we describe the results obtained with (99m)Tc-interleukin-2 in a series of eight normal subjects and of 12 patients with autoimmune thyroid diseases. METHODS: Biodistribution, pharmacokinetics, haematological and systemic toxicity, radiation absorbed dose and in vivo targeting were studied. RESULTS: Results showed rapid plasma clearance of (99m)Tc-interleukin-2 with retention mainly in the kidneys. Biodistribution and kinetics were similar to that observed for (123)I-interleukin-2. No acute systemic toxicity was found; a small decrease in peripheral blood lymphocytes was observed in the first hours only in patients, but it was mild and transient. (99m)Tc-interleukin-2 accumulated, to varying extents, in the thyroid of all patients affected by autoimmune thyroid diseases but not in the thyroid of normal subjects. The effective dose equivalent of a diagnostic activity of (99m)Tc-interleukin-2 (185 MBq) was 1.35 mSv. No correlation was observed between thyroid autoantibodies and uptake of (99m)Tc-interleukin-2. CONCLUSIONS: The use of (99m)Tc-interleukin-2 is safe and simple; the favourable dosimetry and biodistribution and the rapid clearance make it potentially useful for the study of chronic inflammatory diseases such as autoimmune thyroid disease.
Abstract: BACKGROUND: To evaluate the clinical utility of pancreatic scintigraphy with 99mTc-interleukin-2 to identify Type 1 diabetic patients with pancreatic inflammation at diagnosis. METHODS: 99mTc-interleukin-2 scintigraphy was performed on 42 newly diagnosed Type 1 diabetic patients, before and after 1 year of treatment with nicotinamide (25 or 50 mg/kg/day) in addition to intensive insulin therapy. Metabolic status was monitored every 3 months for 1 year. Sixteen normal subjects were studied as control. RESULTS: Significant pancreatic accumulation of 99mTc-interleukin-2 was found in 31% of the patients at the time of diagnosis. Patients positive or negative for pancreatic accumulation of interleukin-2 scintigraphy did not show any difference in metabolic or immunologic parameters at diagnosis. Positive patients, however, showed higher C-peptide values at 3 months and lower insulin requirement at 1 year, compared to negative patients (insulin requirement (IR): 0.33+/-0.11 vs 0.67+/-0.24 IU/kg/day, positive vs negative patients; p=0.0001); patients positive to IL2 scintigraphy treated with nicotinamide at 25 mg/kg were the only group showing a significant reduction in IR 1 year after diagnosis (IRt0: 0.53+/-0.30 vs IRt12: 0.28+/-0.07 IU/kg/day; p=0.013). After 1 year, all the positive patients showed a significant decrease in pancreatic uptake of 99mTc-interleukin-2 (P/B: 7.87+/-2.28 at diagnosis vs 5.00+/-1.23 after 1 year; p<0.0001 paired t-test). CONCLUSION: 99mTc-interleukin-2 scintigraphy at diagnosis of Type 1 diabetes may identify patients with pancreatic inflammation. In such patients, treated with nicotinamide at 25 mg/kg, insulin requirement and pancreatic inflammation after 1 year were significantly reduced suggesting that IL2 scintigraphy may be of potential use for assessing the autoimmune phenomena in endocrine pancreas.
Abstract: We report the case of a 59 years old woman affected by lung and joint sarcoidosis, secondary Sjogren's syndrome refractory to common disease-modifying antirheumatic drugs (DMARDs) that regressed with infliximab and methotrexate. 99mTc-HYNIC-TOC scintigraphy was useful in diagnosis, choice of treatment and follow-up.
Abstract: INTRODUCTION: Information obtained on the IL-2 receptor status of tumour infiltrating lymphocytes in patients suffering from squamous cell carcinoma of the head and neck (SSCHN) before and after IL-2 treatment may lead to a better understanding of the immunological changes and related kinetics induced at the tumour level and ultimately to a strategy that allows selection of those patients that will benefit from IL-2 therapy. This study set out to assess the relationship between (123)I-IL2 single-photon emission computed tomography (SPECT) findings and the presence of IL-2 receptors (CD25 staining) on tumour-infiltrating lymphocytes as well as on SCCHN tumour cells in patients suffering from SCCHN. MATERIALS AND METHODS: Seventeen consecutive patients (12 men; mean age, 57 years) highly suspected to suffer from SSCHN were prospectively included in the study. All patients underwent planar and whole body (123)I-IL2 scintigraphy and underwent surgery or had a biopsy taken within 1 week from imaging. Surgical resected primary lesions as well as biopsy material from primary tumours were histologically analysed with respect to the presence and intensity of CD25 expression on tumour infiltrating lymphocytes and tumour cells (HSCORE). Tumor-to-background (T/N) ratios of the primary tumour derived from planar and tomographic (123)I-IL2 scintigraphy were related to the results derived from histology. RESULTS: All patients suffered from SSCHN. T/N ratios derived from SPECT images were significantly correlated with CD25 lymphocyte HSCOREs (r = 0.66; p = 0.03), but not with CD25 tumour cell HSCOREs. CONCLUSIONS: (123)I-IL-2 SPECT imaging allows for non-invasive imaging of the relative amount of IL-2 receptors present on tumour infiltrating lymphocytes in SCCHN.
Abstract: BACKGROUND: The prevalence of thyroid nodules increases with age, average 4-7% for the U.S.A. adult population, but it is much higher (19-67%) when sub-clinical nodules are considered. About 90% of these lesions are benign and a reliable approach to their preoperative characterization is necessary. Unfortunately conventional thyroid scintigraphy does not allow the distinction among benign and malignant thyroid proliferations but it provides only functional information (cold or hot nodules). The expression of the anti-apoptotic molecule galectin-3 is restricted to cancer cells and this feature has potential diagnostic and therapeutic implications. We show here the possibility to obtain thyroid cancer imaging in vivo by targeting galectin-3. METHODS: The galectin-3 based thyroid immuno-scintigraphy uses as radiotracer a specific (99m)Tc-radiolabeled mAb. A position-sensitive high-resolution mini-gamma camera was used as imaging capture device. Human galectin-3 positive thyroid cancer xenografts (ARO) and galectin-3 knockout tumors were used as targets in different experiments in vivo. 38 mice with tumor mass of about 1 gm were injected in the tail vein with 100 microCi of (99m)Tc-labeled mAb to galectin-3 (30 microg protein/in 100 microl saline solution). Tumor images were acquired at 1 hr, 3 hrs, 6 hrs, 9 hrs and 24 hrs post injection by using the mini-gamma camera. FINDINGS: Results from different consecutive experiments show an optimal visualization of thyroid cancer xenografts between 6 and 9 hours from injection of the radiotracer. Galectin-3 negative tumors were not detected at all. At 6 hrs post-injection galectin-3 expressing tumors were correctly visualized, while the whole-body activity had essentially cleared. CONCLUSIONS: These results demonstrate the possibility to distinguish preoperatively benign from malignant thyroid nodules by using a specific galectin-3 radio-immunotargeting. In vivo imaging of thyroid cancer may allow a better selection of patients referred to surgery. The possibility to apply this method for imaging and treatment of other galectin-3 expressing tumors is also discussed.
Abstract: AIM: Crohn's disease (CD) is a chronic inflammatory bowel disease characterized by a cellular-mediated immune response driven by cytokines secreted mainly by T helper 1 cells (Th1). In active phases of the disease, an increased production and release of tumor necrosis factor a (TNFalpha) by macrophages and monocytes of the lamina propria has been described. The aim of this study was to detect the presence of TNFalpha within the gut mucosa in patients with active CD by using (99m)Tc-labelled chimeric human/mouse monoclonal antibody anti-TNFalpha (Infliximab, Remicade). METHODS: Infliximab has been labeled with (99m)Tc after reduction of disulfide bound by 2-ME method. In vitro binding assay and biodistribution in animal of [(99m)Tc]Infliximab has been performed to evaluate the retention of its biological activity. Ten patients with active CD refractory to conventional medical therapies were studied. Images of the abdomen were acquired at 6 to 20 h after i.v. injection of about 10 mCi of [(99m)Tc]Infliximab and a week later, all patients were also studied with [(99m)Tc]HMPAO-labeled autologous white blood cells (WBC). RESULTS: A product with high labeling efficiency (>95%) and stability has been obtained. In vitro tests with stimulated T-cells expressing TNFalphalpha indicated that [(99m)Tc] Infliximab retains its binding activity to cell bound TNFalpha as compared to unlabelled Infliximab. The degree of [(99m)Tc]Infliximab uptake by the inflamed bowel evaluated at 20 h postinjection was much less than that seen with labeled WBC and with a different distribution. Three of these patients received anti-TNFalpha (Infliximab) for therapeutic purposes with good clinical results despite the scintigraphy with (99m)Tc-Infliximab was negative in 2 of them. CONCLUSION: Scintigraphy with [(99m)Tc]Infliximab shows the presence of little TNFalpha in the affected bowel of patients with active CD. Therefore, the clinical benefit that patients have from Infliximab therapy is unlikely the consequence of a local a reduction of TNFalpha and the mechanism of action of Infliximab, in therapeutic doses, deserves further investigations.
Abstract: Acute inflammatory response to lipopolysaccharide (LPS) exposure is typically associated with cardiac myocyte apoptosis, which is difficult to quantify because of heart tissue specificity. We report here that radioiodinated Annexin V (I-AnxV), a specific ligand of phosphatidylserine exposed by apoptotic cells, allows tissue detection of apoptosis in LPS-treated rat hearts. Heart I-AnxV uptake was significantly increased in all cardiac territories of LPS-treated rats. In contrast, I-human serum albumin myocardial uptake was only slightly increased in LPS-treated rat hearts, suggesting limited changes in vascular protein permeability. Autoradiography of endotoxin-treated rat heart sections with I-AnxV in association with deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling and caspase 3 staining allows identification of double positive cardiac myocytes. Inhibition of apoptosis by caspase inhibitors (i.e., ZVAD.fmk and DEVD.cmk) reduced I-AnxV myocardial uptake in LPS-treated rats. Eventually, endotoxin-treated rats displayed pathological uptake of Tc-annexin in the cardiac mediastinal region whereas zVAD.fmk reduced Tc-annexin mediastinal uptake. Our results show that radioactive I-AnxV signal emerging from LPS-treated rat hearts could be related to the activation of caspase-dependent apoptotic pathway in cardiac myocytes.
Abstract: AIM: This pilot study reports on the uptake of (123)I-interleukin 2 (IL-2) in metastatic renal cell carcinoma (MRCC) patients and its relationship to prognostic factors of response or failure of MRCC to cytokines treatment. METHODS: Nine consecutive patients with MRCC underwent an (123)I-IL-2 scan (6 male and 3 female; mean age 64 years; range 51-78). Uptake in metastases was related to a summed score of 4 independent factors, predictive of rapid progression under cytokine treatment as defined by Negrier et al. RESULTS: Four patients presented with metastases at one site, 4 at 2 sites and one patient at 3 different sites. Summed scores were: 5 patients had a summed score of 1; 3 a summed score of 2 and 1 patient a summed score of 3. Uptake of (123)I-IL-2 by tumor tissue was found in only 2 patients. Uptake occurred in 1 patient with a summed score of 3 and in 1 with a summed score of 2. CONCLUSION: In this small series of patients with MRCC, (123)I-IL-2 uptake was found in tumors of 2 patients who less likely will benefit from cytokine treatment. Additional studies are needed to assess the relationship between the pretreatment uptake of (123)/I-IL2 in MRCC and the response to IL-2 therapy.
Abstract: During the past 3 decades various chemotherapeutics have been directly or indirectly radiolabeled for single photon emission computed tomography (SPECT) and positron emission tomography (PET) imaging. Several of these radiolabeled chemotherapeutics have been injected into patients for the purpose of better understanding their biodistribution and metabolism and to assess whether there exists a relationship between their uptake in tumor tissue and response to treatment. Based on available data, it may be concluded that PET or SPECT imaging with radiolabeled chemotherapeutics provides valuable information that helps to better understand the mechanism of action and the metabolic conversion of unlabeled chemotherapeutics in humans and that helps to provide a rationale for the lack of response to certain chemotherapeutics or for the beneficial effect of biomodulating agents. As for their utility as predictors of response to therapy, their utility is limited to those agents given in monotherapy.
Abstract: PURPOSE: Several new somatostatin analogues have been developed for the diagnosis and therapy of different tumours. Since somatostatin receptors are often over-expressed in medullary thyroid carcinoma (MTC), the aim of our study was to evaluate the utility of scintigraphy with the somatostatin analogue (99m)Tc-EDDA/HYNIC-TOC in MTC in comparison with other diagnostic techniques. METHODS: Forty-five patients with MTC, aged 14-83 years, were investigated. Scintigraphy using (99m)Tc-EDDA/HYNIC-TOC (Tektrotyd) was performed 2 and 4 h post injection of 740 MBq (20 mCi) of the tracer. Other imaging techniques were also applied and analysed in individual cases (ultrasonography, computed tomography, (99m)Tc(V)-DMSA, (131)I-MIBG, (99m)Tc-MDP, (111)In-DTPA-octreotide and (18)F-FDG-PET) and compared with (99m)Tc-EDDA/HYNIC-TOC. RESULTS: In group 1 (eight patients before thyroidectomy), uptake of the tracer was found in the primary tumours. In group 2 (six patients with remission), a false positive result was found in one patient; in the remaining five patients, no pathological foci were visualised. In group 3 (31 patients with post-surgical hypercalcitoninaemia), scintigraphy was true positive in 23 patients (74.2%): uptake in the thyroid bed was found in five patients, in the lymph nodes in 18 and in bone metastases in four. Using (99m)Tc-EDDA/HYNIC-TOC scintigraphy, the overall sensitivity was 79.5%, specificity 83.3%, accuracy 80.0%, positive predictive value 96.9% and negative predictive value 38.5%. CONCLUSION: (99m)Tc-EDDA/HYNIC-TOC is clinically useful for scintigraphy in the follow-up of patients with MTC. It can be used in clinical practice for preoperative evaluation, for localisation of local recurrence or distant metastases and particularly for therapy decision making.
Abstract: AIM: The aim of the present study was to evaluate the diagnostic sensitivity of [(99m)Tc]methoxyisobutylisonitrile ([(99m)Tc]MIBI) in a large series of patients with metastatic differentiated thyroid carcinoma (DTC), as compared with (131)I-whole body scan (WBS) and other diagnostic imaging techniques. METHODS: Eighty-four patients with known metastases from DTC where recruited during the course of replacement thyroxine therapy and undergone [(99m)Tc]MIBI scan. All patients previously performed a (131)I-WBS with thyroglobulin (Tg) measurement and neck ultrasound or computerized tomography, or magnetic resonance imaging, or bone scan or positron emission tomography (PET) scan. RESULTS: Patients were divided in two groups: group A (n=50) with known metastases and positive at a previous (131)I-WBS and group B (n=34) with known metastases, but negative at (131)I-WBS. All patients had elevated serum Tg level in absence of replacement therapy. Technetium-99m-MIBI scan showed 76.2% sensitivity in detecting metastases, Tg during opotherapy 64.3%, and the other imaging techniques combined 86.9%. Sensitivity of [(99m)Tc]MIBI was greater in metastases without (131)I uptake than in metastases with (131)I uptake, although the difference was not statistically significant. CONCLUSION: Technetium-99m-MIBI scan improves sensitivity of Tg measurement in patients with suspected metastases from DTC during the course of opotherapy and is a useful alternative to fluorodeoxyglucose-PET or other imaging techniques in patients with elevated serum Tg and negative (131)I-WBS.
Abstract: The term 'fever of unknown origin' includes a wide range of conditions that often remain undiagnosed. The possibility of an infection must be promptly diagnosed in order to begin appropriate therapy. Imaging with radiopharmaceuticals, computed tomography, magnetic resonance imaging and ultrasound are the most commonly applied techniques, usually performed in addition to blood tests, biopsies or tissue cultures when required. The lack of comparative studies investigating the accuracy of each radiopharmaceutical for the study of fever of unknown origin was the incentive to perform a meta-analysis of peer articles published between 1981 and 2004 (33 papers) describing the use of nuclear medicine imaging for this purpose. Furthermore, infection of subcutaneous devices, brain abscesses and endocarditis must be considered amongst the causes of fevers of unknown origin. Reviews of 23, 10 and 10 papers, respectively (from 1976 to 2005), were performed on these specific topics. The results may be a useful guide for the choice of the optimal radiopharmaceutical(s) and diagnostic strategy to be applied in each clinical condition and for different aims.
Abstract: In vitro assessment of hormone receptor status using a ligand-binding assay or immunohistochemistry in breast cancer patients predicts endocrine responsiveness with an accuracy of only 60%-70%. Assessment of an end product of estrogen receptor stimulation, such as the progesterone receptor, is assumed to provide a measure of functional receptor content and has proven to increase predictive accuracy. In analogy with the estrogen-dependent regulation of somatostatin receptor (SSTR) expression in endocrine-responsive human breast cancer cell lines, efficient antiestrogen treatment in patients may result in a downregulation of SSTR at the cell surface in breast tumors. In vivo imaging of this molecular event by means of sequential (99m)Tc-depreotide scintigraphy could enable selection of breast cancer patients susceptible to endocrine therapy. METHODS: Twenty patients with a diagnosis of advanced breast cancer in whom first- or second-line hormonal therapy was going to be initiated were included. Patients underwent sequential (99m)Tc-depreotide scintigraphy before and 3 wk after initiating hormonal treatment. Follow-up data were retrieved from routine clinical evaluation by means of physical examination, imaging (e.g., bone scan, CT, MRI) and blood analysis. Lesion-to-background ratios (L/BGs) were calculated on planar and SPECT images and a change of >25% between the baseline and follow-up scan was considered significant. RESULTS: At 6 mo after initiation of treatment, 8 patients had stable disease and were considered to be responding to hormonal treatment, whereas 10 patients had progressive disease and were considered to be nonresponders. The positive and negative predictive values of baseline (99m)Tc-depreotide scintigraphy for endocrine responsiveness were 73% (8/11) and 100% (7/7), respectively. Sequential scans were always both positive or both negative. The relative change in (99m)Tc-depreotide uptake between sequential scans significantly differed in responders compared with nonresponders (P= 0.017)-uptake decreased in the first group and increased in the latter. As such, baseline (99m)Tc-depreotide scintigraphy combined with the changes in tracer uptake between the baseline and follow-up scan predicted endocrine responsiveness with an accuracy of 100%. CONCLUSION: Sequential (99m)Tc-depreotide scintigraphy could allow for separation of responders and nonresponders immediately or as early as 3 wk after initiation of treatment.
Abstract: PURPOSE: Several histopathological studies have demonstrated that vulnerable plaques are enriched in inflammatory cells. The aims of this study were: (1a) to test the ability of 99mTc-labelled interleukin-2 (99mTc-IL2) to bind to IL2R-positive (IL2R+) cells in carotid plaques and (1b) to correlate the plaque uptake of 99mTc-IL2, measured in vivo, with the number of IL2R+ cells within the plaque, measured ex vivo by histology (transversal study, TS), and (2) to evaluate changes in 99mTc-IL2 uptake in plaques, before and after treatment with a statin or a hypocholesterolaemic diet (longitudinal study, LS). METHODS: Ultrasound scan was performed for plaque characterisation and localisation. Fourteen patients (16 plaques) eligible for endoarterectomy were recruited for the TS and underwent 99mTc-IL2 scintigraphy before surgery. Nine patients (13 plaques) were recruited for the LS; these patients received atorvastatin or a standard hypocholesterolaemic diet and 99mTc-IL2 scintigraphy was performed before and after 3 months of treatment. RESULTS: The degree of 99mTc-IL2 uptake was expressed as the plaque/background (T/B) ratio. In patients from TS, T/B ratios correlated with the percentage of IL2R+ cells at histology (r = 0.707; p = 0.002) and the number of IL2R+ cells at flow cytometry (r = 0.711; p = 0.006). No correlations were observed between ultrasound scores and either scintigraphic or histological findings. In patients from the LS, the mean 99mTc-IL2 uptake decreased in statin-treated patients (1.75+/-0.50 vs 2.16+/-0.44; p = 0.012), while it was unchanged in the patients on the hypocholesterolaemic diet (2.33+/-0.45 vs 2.34+/-0.5). CONCLUSION: 99mTc-IL2 accumulates in vulnerable carotid plaques; this accumulation is correlated with the amount of IL2R+ cells and is influenced by lipid-lowering treatment with a statin.
Abstract: PURPOSE: Few radiopharmaceuticals have been described for the study of lymphocyte trafficking despite its high clinical relevance. The main difficulty resides in the identification of a suitable highly specific probe to target these cells. Interleukin-12 (IL12) is a heterodimeric cytokine which plays a key role in the development of Th(1) lymphocytes. The aims of the present study were to label IL12 with (99m)Tc, to evaluate its ability to bind to activated T lymphocytes in vitro and to study its biodistribution in normal mice and mice affected by autoimmune colitis. METHODS: IL12 was derivatised with HYNIC-NHS and labelled with( 99m)Tc. An in vitro binding assay was performed on KIT225 cells, an IL12 receptor-positive cell line. (99m)Tc-IL12 biodistribution in normal mice was studied. Targeting experiments were performed in Balb/c mice injected with KIT225 cells and in mice with chemically induced chronic colitis. RESULTS: (99m)Tc-IL12 labelling efficiency ranged between 75% and 85%. Saturation binding analysis revealed a K (d) of 2.09 nM. Results of biodistribution studies showed a predominant hepatic route of excretion. A significant degree of uptake in the spleen and thymus was also observed. In mice injected with KIT225 cells, (99m)Tc-IL12-specific uptake in these cells increased over time. (99m)Tc-IL12 also accumulated significantly in bowel of mice affected by TNBS-induced colitis showing T lymphocyte infiltration at histology, while accumulation in colon from control animals was negligible. CONCLUSION: We conclude that this radiolabelled cytokine is a suitable candidate for specific in vivo imaging of T lymphocytes: a step forward in molecular imaging of immune-mediated processes.
Abstract: The inflammation and infection of bone include a wide range of processes that can result in a reduction of function or in the complete inability of patients. Apart from the inflammation, infection is sustained by pyogenic microorganisms and results mostly in massive destruction of bones and joints. The treatment of osteomyelitis requires long and expensive medical therapies and, sometimes, surgical resection for debridement of necrotic bone or to consolidate or substitute the compromised bones and joints. Radiographs and bone cultures are the mainstays for the diagnosis but often are useless in the diagnosis of activity or relapse of infection in the lengthy management of these patients. Imaging with radiopharmaceuticals, computed tomography and magnetic resonance are also used to study secondary and chronic infections and their diffusion to soft or deep tissues. The diagnosis is quite easy in acute osteomyelitis of long bones when the structure of bone is still intact. But most cases of osteomyelitis are subacute or chronic at the onset or become chronic during their evolution because of the frequent resistance to antibiotics. In chronic osteomyelitis the structure of bones is altered by fractures, surgical interventions and as a result of bone reabsorption produced by the infection. Metallic implants and prostheses produce artefacts both in computed tomography and magnetic resonance images, and radionuclide studies should be essential in these cases. Vertebral osteomyelitis is a specific entity that can be correctly diagnosed by computed tomography or magnetic resonance imaging at the onset of symptoms but only with radionuclide imaging is it possible to assess the activity of the disease after surgical stabilization or medical therapy. The lack of comparative studies showing the accuracy of each radiopharmaceutical for the study of bone infection does not allow the best nuclear medicine techniques to be chosen in an evidence-based manner. To this end we performed a meta-analysis of peer reviewed articles published between 1984 and 2004 describing the use of nuclear medicine imaging for the study of the most frequent causes of bone infections, including prosthetic joint, peripheric post-traumatic bone infections, vertebral and sternal infections. Guidelines for the choice of the optimal radiopharmaceuticals to be used in each clinical condition and for different aims is provided.
Abstract: Over the past 20 years, radiopharmaceutical research has brought to market a wide variety of drugs that aid in the management of infection and inflammation. Finding the best clinical application for existing radiopharmaceuticals can be a challenging task, as clinicians now have to choose from an array of many different radiopharmaceuticals, each suited to identify a specific type of inflammation. With this review, we describe the features of receptor-targeting agents and present the main advantages and limitations to their application in the diagnosis of inflammation and infection. The receptor-specific agents described here include peptides and antibodies as well as radiolabeled antibodies employed for the specific targeting of neutrophils, bacteria, lymphocytes, and molecules involved in inflammatory processes. Because these agents bind to specific receptors, they allow the mapping of receptor expression in vivo. Such mapping represents the future of nuclear medicine imaging, as it aids in diagnosing the type of inflammation, in therapy decision-making, in selecting suitable candidates for therapy, and in evaluating treatment efficacy.
Abstract: Rheumatoid arthritis (RA) is an incapacitating chronic inflammatory disease of the joints that, because of frequent relapses, requires life-long treatment. In patients affected with RA an important treatment objective is to achieve specific immune suppression in order to extinguish the immune process and arrest the disease, thus preventing or delaying complications and avoiding disease recurrence. The side effects of anti-inflammatory drugs given to improve the quality of life of these patients can be reduced with the use of specific immune therapies that block, as selectively as possible, the pathologic mechanism responsible for the disease. New therapeutic options for specific, targeted therapies for treating RA are being developed, and trials to assess the efficacy and safety of these approaches are underway. However, these therapies rely primarily on clinical assessment to evaluate treatment efficacy. It would be useful, therefore, to have an objective and reliable method that directly highlights the immune processes underlying the disease. Currently available radiopharmaceuticals for imaging RA, with a special emphasis on recently developed agents and their use in therapy decision-making and follow-up are the focus of this article.
Abstract: BACKGROUND AND AIM: Osteomyelitis of the foot is the most commonly encountered complication in diabetic patients. Nuclear medicine techniques are usually complementary to radiology in the diagnosis of foot infections; they play an important role in various clinical situations. The aim of this study was to develop a practical guideline to describe the radiopharmaceuticals to be used for different clinical conditions and different aims in diabetic foot infection. METHODS: In this study, we reviewed 57 papers (published between 1982 and 2004; 50 original papers and seven reviews) that described the imaging of the diabetic foot and examined a total of 2889 lesions. We performed data analysis to establish which imaging technique could be used as a 'gold standard' to diagnose infection, evaluate the extent of disease and monitor the efficacy of therapy. RESULTS AND CONCLUSION: We provide a guideline to assist in the selection of the optimal radiopharmaceuticals for different clinical conditions and different aims.
Abstract: Positive experiences with intraarticular infliximab have been reported in patients with rheumatoid arthritis, ankylosing spondylitis, and Behcet's disease. We used intraarticular infliximab to treat resistant knee monarthritis in a patient with spondylarthropathy. Clinical and laboratory improvement was associated with improvement in scintigraphic findings. This approach is less expensive than intravenous administration of infliximab. We suggest that selection of candidates for this innovative therapy should be guided by anti-tumor necrosis factor alpha scintigraphy.
Abstract: Different nuclear medicine modalities are currently used to study inflammatory and infective disorders of the abdomen. They are usually complementary to radiology and endoscopy, but they play a pivotal role in particular clinical situations. Several radiopharmaceuticals (e.g., 111In or 99mTc labelled white blood cells, monoclonal antibodies, human polyclonal immunoglobulins, 75Ga citrate) are commercially available, but they can not be used indifferently to study abdominal inflammatory disorders. The lack of comparative studies showing the accuracy of each radiopharmaceutical for the study of inflammatory/infective abdominal diseases does not allow the best nuclear medicine technique(s) to be chosen in an evidence-based manner. To this end we performed a meta-analysis of peer reviewed articles published between 1984 and 2004 describing the use of nuclear medicine imaging for the study of inflammatory bowel disorders, appendicitis and vascular graft infections. A guideline for the optimal radiopharmaceutical(s) to be used in each clinical condition and for different aims is provided.
Abstract: Idiopathic inflammatory bowel disease (IBD) includes a collection of disorders of the gastrointestinal tract of unknown aetiology, characterized by intestinal inflammation and a chronic relapsing course associated with local and systemic complications. Traditionally, IBD comprises two prototype entities, ulcerative colitis (UC) and Crohn's disease (CD) and an intermediate variant of these diseases, indeterminate colitis which shows overlapping features of the two major forms. Over the last few years, considerable progress has been made in our knowledge of the pathogenesis of IBD, which is complex and derives from genetic, environmental and immunological interactions. The aetiology remains unclear, but it is well established that the lesions and symptoms are associated with over-production of pro-inflammatory cytokines. In this paper we briefly review the pathophysiology and the new therapeutic approaches to IBD, since from these, new achievement depends the appropriate diagnostic exams to be performed and diagnostic flow charts.
Abstract: AIMS AND BACKGROUND: The aim of our study was to investigate the plasma chromogranin A (CgA) and adrenomedullin (AM) levels in patients with pheochromocytomas. METHODS AND STUDY DESIGN: We collected blood samples for measurement of plasma CgA and AM in 21 patients with pheochromocytomas, 43 healthy subjects and 26 patients with solid non-functioning adrenocortical adenomas. In 11 patients with pheochromocytomas plasma CgA and AM were measured again four weeks after tumor removal. CgA and AM were measured by means of a novel solid-phase two-site immunoradiometric assay based on monoclonal antibodies (CgA-RIA CT, CIS bio international) and by a specific radioimmunoassay (RIA, Phoenix Pharm. Inc.), respectively. RESULTS: The mean plasma CgA level (+/- SD) in patients with pheochromocytomas (204 +/- 147.9 ng/mL) was significantly higher (P < 0.001) than that in healthy subjects (41.6 +/- 10.7 ng/mL) and in patients with non-functioning adrenocortical adenomas (47.3 +/- 17.6 ng/mL). The mean plasma AM concentration (+/- SD) in patients with pheochromocytomas (27.5 +/- 10.4 pg/mL) was significantly higher (P < 0.001) than that in HS (13.8 +/- 4.5 pg/mL) and in patients with non-functioning adrenocortical adenomas (16.6 +/- 7.3 pg/mL). Plasma CgA levels correlated with plasma AM levels (r = 0.501; P < 0.02) and with plasma metanephrine levels (r = 0.738; P < 0.0001) in patients with pheochromocytomas. In 11 patients with pheochromocytomas plasma CgA and AM concentrations significantly decreased after tumor removal (P < 0.001 for both). Circulating CgA and AM had a sensitivity of 76.2% and 81%, a specificity of 97.7% and 90.7%, and an accuracy of 91% and 88%, respectively. CONCLUSION: This study demonstrates that circulating CgA and AM levels are increased in pheochromocytoma patients compared with healthy subjects and patients with non-functioning adrenocortical adenomas. Moreover, at the time of diagnosis plasma CgA levels correlated with plasma AM levels and with plasma metanephrine levels in all patients with pheochromocytomas. In conclusion, plasma CgA and AM concentrations may represent additional biochemical parameters for clinical monitoring of patients with pheochromocytomas.
Abstract: In this paper, the use of (123)I-Annexin V for the detection of farnesyltransferase inhibitor (FTI)-induced apoptosis in tumour-bearing athymic mice is described. In vitro binding assays on LoVo cells show time- and dosage-dependent (125)I-Annexin V binding upon treatment with Tipifarnib (Zarnestra, R115777), a selective and potent FTI. In vivo experiments using planar gamma scintigraphy on LoVo inoculated mice show a 40% increased (123)I-Annexin V uptake 8 h after a single oral administration of 100 mg/kg Tipifarnib in 20% beta-cyclodextrin in 0.1 M HCl, as well as after 3 days of twice daily treatments with the same dose. Ex vivo TUNEL assays, detecting end-stage apoptotic cells, correlate significantly with both in vitro and in vivo results. The percentage of necrosis is also increased by Tipifarnib treatment, but is too low to interfere with the (123)I-Annexin V uptake. It can be concluded that (123)I-Annexin V can be used to monitor Tipifarnib-induced apoptosis in LoVo xenograft tumours in athymic mice. Future applications might include the early prediction of FTI response and the selection of FTI-sensitive patients very shortly after treatment initiation. Subsequently, such patients would greatly benefit from a noninvasive and fast therapy evaluation.
Abstract: Graves' disease (GD) is an autoimmune and polygenic disorder. Several studies have shown that human leukocyte antigen (HLA) class II and the cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) gene are involved in the genetic susceptibility. We performed a case control study on 150 patients with GD and 301 controls, matched for age and gender, to verify the association of three polymorphisms located in CTLA-4 region (A49G, [AT](n)-3'UTR, and CT60) and of HLA-DRB1 and DQB1 loci with the disease in an Italian population. The prevalence of patients with GD carrying the G allele of CT60 was significantly higher compared to control subjects (p = 0.02, odds ratio [OR] = 1.82). The allelic frequency of the G allele of CT60 was also significantly higher in patients with GD (p = 0.02). The G allele frequency of A49G in patients was significantly higher compared to control subjects (p = 0.04). The 280 allele phenotype frequency of (AT)(n)-3'UTR was also significantly higher in patients (p = 0.04). The G allele of A49G, the G allele of CT60, and the 280 allele of (AT)(n)-3'UTR microsatellite were significantly increased in patients with GD with thyroid-associated ophthalmopathy (TAO) compared to controls (p = 0.04, p = 0.03, and p = 0.02, respectively), however, we did not find any significant difference between TAO and non-TAO patients. We also found the HLA-DRB1*03 allele to be associated with GD; interestingly, the association of the CTLA-4 markers was independent from the HLA DRB1*03 status. These results highlight the role of the CTLA-4 locus, in addition to HLA, in the susceptibility to GD. Inside the CTLA-4 region, CT60 appears to be the most associated polymorphism to GD, however, further studies are needed to identify the etiologic variant.
Abstract: Cutaneous melanoma is often characterized by the presence of tumor-infiltrating lymphocytes (TILs). The degree of such infiltration and cell activation are considered significant prognostic factors reflecting the host's immune response to the tumor; thus, patients with peritumoral infiltration may have a better prognosis and may also achieve a better response to interleukin-2 (IL2) immunotherapy. There is evidence that the expression of cluster designation (CD) 25 antigen (IL2 receptor [IL2R]) is a good marker of activity of T lymphocytes against melanoma cells. The aim of this study was to evaluate in vivo the binding of 99mTc-IL2 to lymphocytes infiltrating cutaneous melanoma and to determine whether such uptake correlates with immunologic and histologic data, thus providing useful prognostic information for IL2 therapy in patients with advanced disease. METHODS: Thirty patients with cutaneous lesions suspected of being melanoma were studied. Planar gamma-camera images over known tumor sites were acquired 1 h after the injection of 111-185 MBq of 99mTc-IL2. Tumor uptake of 99mTc-IL2 was measured as a target-to-background (T/B) radioactivity ratio. All patients underwent surgery, and histologic evaluation of the resected lesion was performed. The percentage of different peripheral blood lymphocyte subsets (CD3, CD4, CD8, CD16, CD25) and the percentage of IL2R-positive tumor cells on histologic sections were also measured. RESULTS: At final histology, 21 lesions were found to be melanoma and 9 were classified as benign. In 15 of 21 (71%) melanomas and 2 of 9 (22%) benign cutaneous lesions, we found uptake of 99mTc-IL2. The calculated T/B ratios correlated significantly with the number of IL2R-positive TILs. CONCLUSION: 99mTc-IL2 scintigraphy provides a means of in vivo measurement of the extent of tumor infiltration of IL2R-positive cells, thereby providing valuable prognostic information for selection of patients who may benefit from IL2 immunotherapy.
Abstract: An early diagnosis of distant metastases or local recurrences of medullary thyroid carcinoma (MTC) can be achieved by several conventional radiological modalities (e.g., ultrasonography, computed tomography [CT], and magnetic resonance imaging [MRI] as well as by radioisotopic procedures, such as positron emission tomography (PET), scintigraphy with different types of radiopharmaceuticals, and radiolabeled receptor-ligands in particular. The aim of this study was to evaluate the clinical utility of 99mTc-EDDA/HYNIC-TOC, a new octreotide derivative, to detect recurrences of disease or distant metastases in MTC. Images obtained of 5 patients with high levels of serum calcitonin were compared to findings obtained with other diagnostic procedures: 111In-octreotide, 99mTc-DMSA-V, 18F-flouro-D-deoxyglucose-PET, and CT/MRI. 99mTc-EDDA/HYNIC-TOC was positive in all patients and showed 15 areas of pathological uptake in the cervical and mediastinal regions. 111In-octreotide was positive in 3 of 3 patients and showed 4 areas, compared to 8 of 99mTc-EDDA/HYNIC-TOC. 99mTc-V-DMSA was positive in 3 of 4 patients but showed 6 pathological areas, compared to 13 of 99mTc-EDDA/HYNIC-TOC. 18F-FDG-PET was positive in 5 of 5 patients but showed only 11 areas, compared to 15 of 99mTc-EDDA/HYNIC-TOC. The CT scan was positive in only 2 patients. In conclusion, 99mTc-EDDA/HYNIC-TOC detected more sites of pathological uptake than other modalities, showed better imaging properties than 111In-octreotide, and might be the radiopharmaceutical of choice for providing a rationale for radioisotopic therapy.
Abstract: AIM: Aim of the present study was to compare in vitro the labelling efficiency (LE) and cell viability (TBE) of autologous leukocytes labelled with (99m)Tc-SnF(2) and (99m)Tc-HMPAO, and to evaluate the quantity and quality of spontaneously released (99m)Tc (SR) from labelled cells at several time points after labelling. METHODS: A total of 14 patients with different diseases and 18 normal subjects were included in this study. A blood sample was collected from each patient; purified autologous leukocytes were divided into 2 samples and labelled with (99m)Tc-SnF(2) and (99m)Tc-HMPAO. LE was evaluated at the end of labelling and TBE and SR were evaluated at 10 min and 1 h, 2 h and 4 h after labelling. RESULTS: LE of (99m)Tc-SnF(2)-WBC was higher than (99m)Tc-HMPAO-WBC (61.2+/-18.7% and 43.3+/-11.3; p<0.0001) and we found an inverse correlation between blood glucose and labelling efficiency for both methods (p=0.02). Minimal differences were also observed between 2 methods after 10 min and 1 h, as far as the cell viability is concerned. The percentage of radioactivity spontaneously released from (99m)Tc-SnF(2)-WBC was significantly higher compared to (99m)Tc-HMPAO-WBC at each time point. Radioactivity released from labelled cells was predominantly (99m)Tc-SnF(2) and (99m)Tc-HMPAO with few free (99m)Tc (<20%). CONCLUSION: Both radiopharmaceuticals are not toxic for WBC. Labelling with (99m)Tc-SnF(2) give a higher LE than with (99m)Tc-HMPAO; however, radiolabelled colloids are more released from labelled cells over a period of 4 h. While (99m)Tc-HMPAO is physiological excreted into gastrointestinal tract, (99m)Tc-SnF(2) can be re-uptaken in vivo by reticulo-endothelial cells of liver and spleen. These findings suggest that (99m)Tc-SnF(2)-WBC might be better than (99m)Tc-HMPAO-WBC for studying inflammatory bowel diseases.
Abstract: The 17th IRIST (International Research Group on Immunoscitigraphy and Therapy) meeting was held July 27-29, 2004, at the Ghent University Hospital, Ghent, Belgium. Cochairs Christophe Van de Wiele and Alberto Signore brought together basic researchers, clinicians, radiopharmacists, and nuclear medicine specialists to discuss progress in single photon emission computed tomography (SPECT) and positron emission tomography (PET), using radiolabeled antibodies and peptides for imaging biologic properties related to the effectiveness of available treatment options and for treatment of cancer patients. The format of the conference was the presentation of research that focused on the basic and translational biology of cancer and on current state-of-the-art radiopharmacy and related SPECT and PET imaging techniques for the purposes described above. This report summarizes the 17th International IRIST Congress.
Abstract: Because of its potential to allow for noninvasive, repetitive, and selective in vivo identification of the site and extent of apoptotic cell death and for monitoring cell death kinetics without the need for invasive biopsy, radiolabeled annexin-V is of major clinical relevance. This paper reviews available preclinical and clinical data on radiolabeled annexin-V pertaining to the domain of monitoring response to radiotherapy and chemotherapy, focusing especially on advantages and drawbacks of the different labeling procedures for the radiolabeling of annexin-V.
Abstract: We performed a bibliometric search covering a 1-year period to evaluate the number and the scientific "weight" of nuclear medicine papers published from European as compared with other countries. The scientific impact of our discipline was evaluated according to the impact factor of each publication, and we also aimed to identify those countries and topics that are making the principal contributions to the development of our discipline. To this end, a search on MEDLINE (PubMed) was run to find all peer-reviewed articles published between April 2002 and May 2003, using isotope definitions as search terms. A total of 3,292 publications were identified. Of these, 650 were of no nuclear medicine interest, 229 were reviews and 82 had no country specified. In absolute numbers, Europe leads research in nuclear medicine (939 papers, 38.9%) followed by the USA (608 papers, 25.2%). Among European countries, Germany is the nation that is currently making the greatest contribution to the scientific production of nuclear medicine in Europe. Articles concerning the use of nuclear medicine in oncology account for more than one-quarter of all published nuclear medicine papers.
Abstract: The follow-up of differentiated thyroid cancer (DTC) is currently performed by serum Tg levels determination and whole body scan (WBS) with 131I. In this regard, the latter represents the main tool to localize metastatic tissue, but is characterized by the induction of severe hypothyroidism. Moreover, WBS displays poor sensitivity in poorly differentiated tumors due to a loss of iodine uptake capacity. AIM: In this study we describe an alternative tracer, radiolabeled rhTSH, for the diagnosis of non-iodine uptaking DTC metastases. METHODS: rhTSH was iodinated with 125I or 123I using an enzymatic method with lactoperoxidase/glucose oxidase. In vitro stability of labeled compounds was assessed in saline and serum and in vivo studies were performed in tumor-bearing nude mice. Three mice were inoculated with ARO cells (TSH receptor negative) and three with PTC-1 cells (TSH receptor positive). After 25 days, mice were injected with 10 microg of 123I-rhTSH (100 microCi) and static images were acquired at 30 minutes, 1, 2, and 3 hours. Animals were then sacrificed and dissected for organ counting. RESULTS: RhTSH was radioiodinated to high specific activity: 132.2 mCi/mg for 123I-rhTSH, 94.3 for 125I-rhTSH. In vitro stability tests revealed no significant release of radioiodine. A clear tumor uptake was detectable after 2 hours in all animals implanted with PTC-1. CONCLUSION: Results obtained so far suggest that radiolabeled rhTSH might be a promising radiopharmaceutical for diagnosis and follow-up of DTC.
Abstract: Radiolabelled cytokines and chemokines are a group of radiopharmaceuticals that, by highlighting in vivo the binding to specific high-affinity receptors expressed on selected cell populations, allow the molecular and functional characterisation of immune-mediated processes Recently, several authors have described the use of radiolabelled cytokines and chemokines not only for imaging of inflammation and infection, but also as an approach to study in vivo the biology of primary and metastatic cancer cells. The latter avenue of research has been pursued particularly to help oncologists in therapeutic decision making and to follow up the efficacy of new immune therapies. In this paper we describe the characteristics of cytokines and chemokines, focussing on their role as radiopharmaceuticals for the imaging of cancer cells in vivo, a new challenge for molecular nuclear medicine.
Abstract: Tc-99m MIBI is a small lipophilic radioligand that enters cells by diffusion and is preferentially trapped in mitochondria. As a result of the high mitochondrial activity in tumors, Tc-99m MIBI accumulates significantly more in tumor tissue compared with normal tissues. Accordingly, Tc-99m MIBI has been used successfully to visualize primary, metastatic, and recurrent tumor. In brain tumors, Tc-99m MIBI SPECT has been shown to identify tumor recurrence after treatment in high-grade gliomas. In this report, early (30 minutes after injection) and delayed (4 hours after injection) Tc-99m MIBI SPECT did not visualize a histopathologically proved recurrent high-grade oligodendroglioma. Increased vascular supply, disruption of the blood-brain barrier, high-grade cancer, and viability of tumor cells are decisive factors related to increased Tc-99m MIBI uptake in brain tumors. However, the authors' results suggest that still other mechanisms may be involved in Tc-99m MIBI accumulation, which may account for false-negative imaging in brain tumors.
Abstract: Crohn's disease (CD) is a chronic inflammatory bowel disease that may involve the whole gut. Marked intestinal T cell and macrophage activation is a key feature of the disease. Polymorphonuclear cell infiltration is also observed in the diseased gut, mainly during active inflammation. Scintigraphic detection of granulocytes and activated lymphocytes infiltrating the gut wall may be useful in identifying a subgroup of patients with clinically inactive CD who are undergoing early clinical relapse. The aims of the present study were (a) to compare the effectiveness of scintigraphy with (99m)Tc-labelled interleukin-2 ((99m)Tc-IL2) and with (99m)Tc-HMPAO labelled granulocytes ((99m)Tc-WBC) in detecting the presence and extent of bowel inflammation in patients with long-term inactive CD (>12 months) and (b) to assess the accuracy of these techniques in predicting future disease relapse. We studied 29 patients with ileal and/or colonic CD in stable clinical remission (Crohn's Disease Activity Index <150 for at least 12 months) using both (99m)Tc-IL2 and (99m)Tc-WBC scintigraphy in order to evaluate the extent of acute and chronic inflammation in the bowel. Planar and single-photon emission tomography images were acquired in each patient at 1 h p.i. For quantitative analysis of (99m)Tc-IL2 uptake, the abdomen was divided into 32 regions of interest. Despite the absence of symptoms, 18 patients (62%) showed a positive (99m)Tc-IL2 and 18 (62%) a positive (99m)Tc-WBC scan. Only 12 patients (41.4% of the total group) were positive on both scans, and the sites of IL2 and granulocyte bowel uptake were usually located in different segments, indicating that in CD, acute and chronic inflammation can be present in different sites. As far as the prognostic role of the two scans in predicting future disease relapse is concerned, both (99m)Tc-IL2 and (99m)Tc-WBC scintigraphy showed a high negative predictive value (1.00 and 0.91, respectively) but a weak positive predictive value (0.44 and 0.39, respectively). Nevertheless, Kaplan-Meier curves generated between scintigraphic findings and time free from disease relapse were statistically different only for (99m)Tc-IL2 scintigraphy (log-rank test, P=0.013). These results indicate that (99m)Tc-IL2 scintigraphy can be useful in selecting CD patients in clinical remission who could benefit from preventive therapy to avoid disease relapse.
Abstract: We describe in detail the labelling of interleukin-2 with I ( I-IL2), its biochemical characterization, the binding assay and its use for the detection of tissues infiltrated with mononuclear cells. Human recombinant IL2 was labelled using an enzymatic method and its biochemical characterization was performed using high performance liquid chromatography (HPLC) analysis of cyanogen bromide-cleaved protein. biological and binding assays were performed on CTLL-2 cell line and on activated peripheral blood lymphocytes. studies were performed 1 h after administration of 2-3 mCi of I-IL2 in 10 newly diagnosed type 1 diabetes patients, five pre-diabetic patients, 10 Hashimoto's thyroiditis patients, 10 coeliac disease patients and 10 normal volunteers. I-IL2 scintigraphy allowed the detection and quantification of activated mononuclear cells in several affected tissues. In detail, I-IL2 accumulation was detected in the thyroid of all patients affected by Hashimoto's thyroiditis, in the bowel of all coeliac disease patients and in the pancreas of all pre-type 1 diabetic patients. By contrast, in newly diagnosed type 1 diabetics, I-IL2 scan was positive in five of the 10 studied patients. I-IL2 scintigraphy may be useful for studying autoimmune phenomena and in diagnostic protocols to evaluate the presence of other tissue involvement in patients with an organ-specific autoimmune disease.
Abstract: Radiolabelled cytokines and chemokines are a new group of radiopharmaceuticals. These, by binding to specific receptors expressed on selected cell populations, enable the histological and functional characterization of immune-mediated processes, in vivo. Clinical studies have demonstrated the efficacy of using this type of scintigraphy in detecting sites of acute inflammation (infection) and chronic (T-cell-mediated) inflammation. Recent studies are focusing on the possible use of radiolabelled cytokines and chemokines for the biological characterization of cancer cells in vivo. In particular, the homing of metastases into specific tissues could depend on the chemoattraction of these tissues, mediated by soluble chemokines that bind to specific receptors expressed on cancer cells. These studies will generate a deeper knowledge of the molecular mechanism of tumor metastasis and lead to new therapies in nuclear medicine.
Abstract: BACKGROUND: It has been recently demonstrated that apoptosis is involved in beta-cell destruction in the NOD mouse model of diabetes. The aim of the present study was to investigate whether IL-15, a cytokine involved in the modulation of the apoptotic process, is capable of modifying the natural history of diabetes and/or insulitis in pre-diabetic NOD mice. The rationale for the use of IL-15-IgG2b recombinant cytokine is related to its long half-life (28 +/- 4 h). METHODS: At 10 weeks of age, 2 groups of 24 female mice were treated with single or multiple i.p. doses of IL-15-IgG2b respectively. As control, 2 groups of 24 age- and litter-matched female mice were injected intra-peritoneally with single or multiple doses of IgG2b immunoglobulin. RESULTS: Diabetes incidence at 33 weeks of age was lower in the group of mice treated with multiple doses than in the control group (p = 0.03). The cumulative incidence of diabetes at 33 weeks of age between single-dose treated mice and the control group was similar. No significant differences in the calculated index of insulitis were observed in all treated and control mice. CONCLUSIONS: We conclude that IL-15-IgG2b reduces the cumulative incidence of diabetes, without affecting the extent and severity of the insulitis process. Considering this and the well-defined anti-apoptotic effects of IL-15, we suggest that the reduction of diabetes incidence could be due to a down-regulation of beta-cell apoptosis.
Abstract: Chronic inflammatory diseases usually lead to fibrosis of the target organ and consequent hypo function. They are often relapsing, invalidating and require life-long treatment. In this class of patients it is very important to try and achieve specific immune suppression to extinguish the immune process with the aim of preventing the disease, preventing or delaying complications and avoiding disease relapse, often requiring surgical intervention. It is important that, while attempting to improve the quality of life of these patients by means of anti-inflammatory drugs, side effects are reduced to a minimum via the use of specific immune therapies that block as selectively as possible the pathologic mechanism responsible for the disease. New therapeutic options are being developed for specific targeted therapies. Several trials are being performed to assess the efficacy and safety of this approach. All of them, however, rely on the clinical assessment of the patients to evaluate the effect of treatment. It would be important to use an objective and reliable method to highlight directly the immune process underlying the individual disease. This manuscript reviews the radiopharmaceuticals available or recently developed for imaging chronic inflammatory diseases and their use for therapy decision making and follow-up.
Abstract: Reliable assays that could assess treatment response more rapidly or even predict responsiveness of breast tumours to chemotherapy would be very valuable as they would allow for adjustment of ineffective treatment and discontinuation of ineffective treatment in an early phase. As with effective cancer therapy, changes in tumour physiology, metabolism and proliferation do often precede volumetric changes routinely measured by morphological imaging modalities, for example, radiography and computerized tomography, assessment of these parameters by means of single photon emission computerized tomography (SPECT) or positron emission tomography may provide more sensitive and earlier markers of tumour cell death or growth inhibition. This paper reviews the available literature on the role of SPECT and PET in the measurement and visualisation of breast tumour metabolism (glucose utilization and protein synthesis rate), apoptosis induction and chemotherapy resistance mechanisms as predictors or early markers of tumour response or non-response to chemotherapeutic options in patients suffering from breast carcinoma.
Abstract: Tumour angiogenesis is essential for growth, invasion and metastasis. Retrospective studies suggest that it is an independent prognostic factor that merits prospective validation. Furthermore, as tumour blood vessels show many differences from normal vessels and are not genetically unstable, they form a key area for therapy development. However, as anti-angiogenic therapy is primarily cytostatic and not cytotoxic, novel tailor-made specific end-points for treatment monitoring are required. In this regard, suitable molecular parameters for imaging tumour angiogenesis by means of nuclear medicine are being explored. Here we review current knowledge on the multiple pathways controlling tumour angiogenesis and try to assess which are the most clinically relevant for nuclear medicine imaging. Parameters that may influence the imaging potential of radiopharmaceuticals for angiogenesis imaging such as molecular weight and structure, their targeted location within the tumour and their usefulness in terms of specificity and constancy of the targeted molecular pathway are discussed.
Abstract: Radiopharmaceuticals used for in vivo imaging of inflammatory conditions can be conveniently classified into six categories according to the different phases in which the inflammatory process develops. The trigger of an inflammatory process is a pathogenic insult (phase I) that causes activation of endothelial cells (phase II); there is then an increase of vascular permeability followed by tissue oedema (phase III). Phase IV is characterised by infiltration of polymorphonuclear cells, and a self-limiting regulatory process called apoptosis is observed (phase V). If the inflammatory process persists, late chronic inflammation takes place (phase VI). In some pathological conditions, such as organ-specific autoimmune diseases, chronic inflammation is present early in the disease. The aim of nuclear medicine in the field of inflammation/infection is to develop noninvasive tools for the in vivo detection of specific cells and tissues. This would allow early diagnosis of initial pathophysiological changes that are undetectable by clinical examination or by other diagnostic tools, and could also be used to evaluate the state of activity of the disease during therapy. These potential applications are of great interest in clinical practice. In this review, we describe the various approaches that have been developed in the last 25 years of experience. Recent advances in the diagnosis of inflammatory processes have led to the development of specific radiopharmaceuticals that are intended to allow specific stage-related diagnosis.
Abstract: Radiolabeled cell-surface peptide receptor-binding molecules are emerging as an important class of radiopharmaceuticals. Their binding to specific cell membrane receptors allows for noninvasive assessment of regional receptor proteomics in vivo. Information thus obtained can be used for diagnostic purposes and for predicting and monitoring response to treatment. This paradigm also applies to pulmonary diseases. In this review, available radiopharmaceuticals of great potential or already in clinical use for imaging of lung cancer, lung inflammation and infection and pulmonary embolism are discussed. In lung cancer, somatostatin receptor imaging by means of technetium-99m (99mTc)-octreotide scintigraphy has proven useful for characterizing malignancy in solitary pulmonary nodules. Additionally, several radiopharmaceuticals targeting tyrosine-kinase, e.g. 99mTc labeled epidermal growth factor and indium-111 (111In)-diethylene triamine penta-acetic acid-trastuzumab, or G-protein coupled receptors, e.g. 99mTc-bombesin, iodine-123-vasoactive intestinal peptide and 111In-tetraazacyclododecane tetra-acetic acid (DOTA)-cholecystokinine-B, are being explored for their diagnostic as well as treatment monitoring potential. With the purpose of better evaluating the source of pulmonary embolism, as well as to differentiate acute from chronic deep venous thrombosis, several radiolabeled peptides targeting the glycoprotein IIb/IIIa fibrinogen receptor found on activated platelets have been developed. Out of these, 99mTc-P280 is now approved by the US Food and Drug Administration for scintigraphic imaging of suspected acute venous thrombosis in the lower extremities of patients. In the field of lung inflammation and infection, non-specific 111In and 99mTc-human polyclonal immunoglobulins have been successfully used to identify the presence and extent of Pneumocystis carinii, cytomegalovirus, Mycobaterium avium and fungal infections in patients with HIV infection. The clinical role of other radiopharmaceuticals such as 99mTc-J001X, a nonpyrogenic acylated polygalactoside isolated from Klebsiella pneumoniae and binding with high affinity to CD11b and CD14 lipopolysaccharide receptors expressed on monocytes/macrophages, and 111In-octreotide, binding to up-regulated somatostatin receptors on activated lymphocytes needs to be further defined.
Abstract: Positron emission tomography (PET) provides a powerful means to non-invasively image and quantify protein expression and biochemical changes in living subjects at nano- and picomolar levels. As the field of molecular imaging develops, and as advances in the biochemistry, pharmacology, therapeutics, and molecular biology of disease are made, there is a corresponding increase in the number of clinically relevant, novel disease-associated biomarkers that are brought to the attention of those developing imaging probes for PET. In addition, due to the high specificity of the PET radiotracers being developed, there is a demand for PET cameras with higher sensitivity and resolution. This manuscript reviews advances over the past five years in clinical and pre-clinical PET instrumentation and in new PET probes and imaging methods associated with the latest trends in the molecular imaging of cancer. Included in the PET tracer review is a description of new radioligands for steroid receptors, growth factor receptors, receptor tyrosine kinases, sigma receptors, tumor-associated enzymes, gene reporter probes, markers for tumor hypoxia and metabolism, and sites associated with angiogenesis and cellular proliferation. The use of PET imaging in drug development, including the monitoring of cancer chemotherapy, also is discussed.
Abstract: Radiolabelled peptides are an emerging class of radiopharmaceuticals that share chemical and biological properties. From the chemical point of view they have a poly-amino acid structure varying from 3 to more that 200 amino acids, and they are labelled with different isotopes directly or by a linker. Biologically, they bind to specific cell membrane receptors, thus providing in vivo histopathological information for diagnostic purposes, therapy follow-up or targeted radiotherapy. This paper reviews most of the radiolabelled peptides that have been tested in animals and humans in the fields of oncology, neurology, cardiology, inflammation/infection, atherosclerosis and thrombosis. A new classification is also proposed for peptides targeting tumour cells based on the biological function of target receptors. These tailored radiopharmaceuticals are the basis of the new era of "molecular nuclear medicine".
Abstract: Coeliac disease is diagnosed by the presence of specific antibodies and a jejunal biopsy showing mucosal atrophy and mononuclear cell infiltration. Mucosal cell-mediated immune response is considered the central event in the pathogenesis of coeliac disease, and untreated coeliac patients show specific features of T-cell activation in the small intestine. Here we describe the use of iodine-123-interleukin-2 scintigraphy in coeliac patients as a non-invasive tool for detection of lymphocytic infiltration in the small bowel and its use for therapy follow-up, and we demonstrate the specificity of binding of labelled-IL2 to activated lymphocytes by ex-vivo autoradiography of jejunal biopsies. 123I-IL2 was administered i.v. [74 MBq (2 mCi)], and gamma camera images were acquired after 1 h. Ten patients were studied with 123I-IL2 scintigraphy at diagnosis and seven were also investigated after 12-19 months of gluten-free diet. Results were expressed as target-to-background radioactivity ratios in six different bowel regions before and after the diet. At the time of diagnosis all patients showed a significantly higher bowel uptake of 123I-IL2 than normal subjects (P < 0.003 in all regions). A significant correlation was found between jejunal radioactivity and the number of IL2R + ve lymphocytes per millimetre of jejunal mucosa as detected by immunostaining of jejunal biopsy (r2 = 0.66; P = 0.008). Autoradiography of jejunal biopsies confirmed that labelled-IL2 only binds to activated T-lymphocytes infiltrating the gut mucosa. After 1 year of the diet, bowel uptake of 123I-IL2 significantly decreased in five out of six regions (P < 0.03), although two patients still had a positive IL2 scintigraphy in one region. We conclude that 123I-IL2 scintigraphy is a sensitive non-invasive technique for assessing in vivo the presence of activated mononuclear cells in the bowel of patients affected by coeliac disease. Unlike jejunal biopsy, this method provides information from the whole intestine and gives a non-invasive measure of the effectiveness of the gluten-free diet.
Abstract: Activated mononuclear cells expressing interleukin-2 (IL2) receptors (IL2-Rs) heavily infiltrate the Crohn's disease (CD) gut wall. A new technique for the in vivo detection of tissue infiltrating IL2-R positive (IL2R+ve) cells was developed based on 123I-IL2 scintigraphy. The aim of this study was to investigate whether 123I-IL2 accumulates in the CD gut wall in different phases of the disease and to evaluate the specificity of 123I-IL2 binding to activated IL2R+ve cells infiltrating the gut wall. METHODS: Fifteen patients with ileal CD (10 active and 5 inactive) and 10 healthy volunteers were studied by 123I-IL2 scintigraphy. Six patients with active CD were studied before and after 12 wk of steroid treatment. After scintigraphy, patients were followed up for 29-54 mo. Ex vivo autoradiography was performed to determine specificity of 125I-IL2 binding to IL2R+ve cells. For bowel scintigraphy, 123I-IL2 (75 MBq) was injected intravenously and gamma camera images were acquired after 1 h. Bowel radioactivity was quantified in 64 regions of interest (ROIs). RESULTS: Autoradiography showed specific binding of 125I-IL2 to IL2R+ve mononuclear cells infiltrating the CD gut wall. Intestinal 123I-IL2 uptake assessed by the number of positive ROIs was higher in patients with active or inactive CD than in healthy volunteers (P < 0.0001 and P = 0.03, respectively) and positively correlated with the CD activity index (P = 0.01). 123I-IL2 intestinal uptake significantly decreased in patients with CD in steroid-induced remission (P = 0.03). A significant correlation was observed between the number of positive ROIs and time to disease relapse. CONCLUSION: 123I-IL2 accumulates in the diseased CD gut wall by specific binding to IL2R+ve cells, infiltrating the involved tissues. 123I-IL2 scintigraphy may be an objective tool for the in vivo assessment of intestinal activated mononuclear cell infiltration.
Abstract: The diagnosis of inflammatory processes is an important goal in medicine. In some cases the diagnosis is easy, based on the clinical history and the physical examination of the patient. Other cases are more difficult to diagnose because they are asymptomatic or with non-specific symptoms. Thus, several imaging techniques have been developed for the diagnosis of inflammatory processes, from the simple X-ray to the more sophisticated computerised tomography, magnetic resonance imaging and nuclear medicine scan. They provide different information and their role in different diseases will be discussed in this review with particular emphasis on the expanding field of the use of radiolabelled cytokines for imaging infection/inflammation. So far, IL-1, IL-1ra, IL-2, IL-6, IL-8, IL-10, IL-12 p40, G-CSF, IFN-gamma and EGF have been radiolabelled for in vivo targetting of different leukocyte subsets with promising results for their clinical use.
Abstract: We previously described a Sardinian family in which the probands had a severe form of hypercholesterolemia, suggestive of familial hypercholesterolemia (FH). However, low density lipoprotein (LDL) receptor activity in fibroblasts from these subjects and LDL binding ability were normal. The characteristics of the pedigree were consistent with an autosomal recessive trait. Sitosterolemia and pseudohomozygous hyperlipidemia were ruled out. A second Sardinian kindred with similar characteristics was identified. Probands showed severe hypercholesterolemia, whereas their parents and grandparents were normolipidemic. FH, familial defective apoprotein (apo) B, sitosterolemia, and cholesteryl ester storage disease were excluded by in vitro studies. We addressed the metabolic basis of this inherited disorder by studying the in vivo metabolism of LDL in 3 probands from these 2 families. 125I-LDL turnover studies disclosed a marked reduction in the fractional catabolic rate (0.19+/-0.01 versus 0.36+/-0.03 pools per day, respectively; P<0.001) and a significant increase in the production rate [20.7+/-4.4 versus 14. 0+/-2.4 mg. kg-1. d-1, respectively; P<0.01] of LDL apoB in the probands compared with normolipidemic controls. We then studied the in vivo biodistribution and tissue uptake of 99mtechnetium-labeled LDL in the probands and compared them with those in normal controls and 1 FH homozygote. The probands showed a significant reduction in hepatic LDL uptake, similar to that observed in the FH homozygote. A reduced uptake of LDL by the kidney and spleen was also observed in all patients. Our findings suggest that this recessive form of hypercholesterolemia is due to a marked reduction of in vivo LDL catabolism. This appears to be caused by a selective reduction in hepatic LDL uptake. We propose that in this new lipid disorder, a recessive defect causes a selective impairment of LDL receptor function in the liver.
Abstract: Autoimmune diseases represent a heterogeneous group of pathologies with a wide range of immunological changes and clinical presentations. The clinical onset of the disease commonly occurs when signs and symptoms of target tissue hypofunction appear; complications can also be present. The aim of an imaging diagnostic technique in this context is to correctly evaluate the disease extent and severity for appropriate treatment and to follow up the efficacy of therapy. In addition, identification of subjects at risk and the preclinical diagnosis may allow disease prevention. Ultrasound (US), conventional radiology and computed tomography (CT) are often used for a detailed morphological study of tissues involved; magnetic resonance (MRI) may also demonstrate biochemical and structural tissue changes. Nuclear medicine techniques are known for their sensitivity and specificity and in recent years an expanding field is represented by the development of radiolabelled receptor ligands. New radiopharmaceuticals able to bind in vivo to specific receptors have been introduced allowing the non invasive detection of changes in affected tissues. The relevant criteria to choose different diagnostic approaches in several autoimmune diseases are discussed in this review. In particular the role and contribution of nuclear medicine for the study of autoimmune diseases have been described.
Abstract: BACKGROUND: Intensive insulin therapy is the gold standard by which Type 1 diabetes is treated. In addition to this therapy, administration of nicotinamide (NA) can be beneficial. This concept is reinforced by the results of a recent meta-analysis of the use of NA in patients with recent-onset Type 1 diabetes. METHODS: In this study we compared two different doses of NA in 74 patients with duration of Type 1 diabetes <4 weeks (mean age 13 years). Patients were randomly allocated in blind to two treatment groups: 38 patients received a dose of 25 mg/kg (b.w.) of NA and 36 patients received a dose of 50 mg/kg (b.w.) of NA. Intensive insulin therapy was carried out in order to optimize metabolic control as soon as possible after diagnosis and to maintain blood glucose level as near to normal as possible. Response to therapy was monitored throughout the study by investigating the occurrence of clinical (complete) remission defined, according to the recommendations of the International Diabetes Immunotherapy Group, as restoration of normal fasting and post-prandial blood glucose without any insulin administration for more than 2 weeks. Moreover, the integrated measures of metabolic control (C-peptide, HbA(1c) and insulin dose) were analysed at 3- month intervals up to 1 year after diagnosis. RESULTS: There were no significant differences in the integrated measures of metabolic control between the two NA treated groups either at onset of the disease or at each 3-month interval up to 1 year after diagnosis, although there was a tendency toward higher insulin dosages in the 50 mg NA group. No significant differences were observed in the rate of clinical remission between the two groups. CONCLUSION: We conclude that patients with recent-onset Type 1 diabetes treated with two different doses of NA, in addition to intensive insulin therapy, show similar residual beta-cell function 1 year later. Since both doses of NA are likely to be effective in reducing beta-cell dysfunction, the smaller dose of 25 mg/kg NA would be sufficient as a higher dose may induce insulin resistance.
Abstract: The aim of this study was to evaluate the diagnostic significance of the first serum thyroglobulin (Tg) measurement, performed 40 days after total thyroidectomy for differentiated thyroid carcinoma and prior to the ablation of residual thyroid tissue by means of iodine-131 therapy. In a retrospective study we examined 334 consecutive patients followed up for 4-16 years by means of regular Tg measurements, (131)I whole-body scans (WBS) and other diagnostic techniques, if necessary. In 79 patients metastases were discovered (32 lymph node and 47 distant metastases) within 18 months following thyroidectomy. Mean values of first Tg were significantly higher in patients with than in patients without metastases (258.9+/-310.6 vs 15.9+/-19.6 ng/ml; P<0.0001). Receiver operating characteristic (ROC) curve analysis of data revealed that for first Tg values higher than 69.7 ng/ml, the positive predictive value for the presence of metastases exceeded 90%. No statistically significant correlation was found between first Tg value and either thyroid-stimulating hormone (TSH) value or percentage of (131)I uptake by residual thyroid tissue. No other parameter (age, histological type, site of metastases, (131)I uptake by metastases) was significantly related to the first Tg value. We conclude that the first Tg measurement after total thyroidectomy provides a useful early diagnostic indication of metastatic disease in spite of the presence of a post-surgical thyroid remnant, and that this holds true regardless of the TSH value and WBS result. This early information is of clinical relevance for patient follow-up.
Abstract: The CD95 death receptor plays an important role in several physiological and pathological apoptotic processes involving in particular the immune system. CD95 ligation leads to clustering of the receptor cytoplasmic "death domains" and recruitment of the zymogen form of caspase-8 to the cell surface. Activation of this protease through self-cleavage, followed by activation of downstream effector caspases, culminates in cleavage of a set of cellular proteins resulting in apoptosis with disassembly of the cell. It is very well known that the extracellular region of the CD95 receptor is required for CD95L interaction and that the death domain is necessary for the induction of the apoptotic signaling. Here, we identified and characterized a novel CD95 ligand- and death domain-independent oligomerization domain mapping to the NH(2)-terminal extracellular region of the CD95 receptor. In vitro and in vivo studies indicated that this domain, conserved among all soluble CD95 variants, mediates homo-oligomerization of the CD95 receptor and of the soluble CD95 proteins, as well as hetero-oligomerization of the receptor with the soluble variants. These results offer new insight into the mechanism of apoptosis inhibition mediated by the soluble CD95 proteins and suggest a role of the extracellular oligomerization domain in the regulation of the non-signaling state of the CD95 receptor.
Abstract: The relationship between Fas-mediated apoptosis and Type 1 diabetes is currently under investigation. Fas/Fas ligand interaction could be involved both in the insulitis process and in beta-cell death. Nevertheless, different mechanisms appear to be involved in human Type 1 diabetes and in NOD mice. In the present work, we review recent evidence of the role of the Fas/Fas ligand system in human and NOD mouse diabetes, describing possible hypotheses for its involvement in the pathogenesis of the disease, with possible implications for therapy and islet transplantation.
Abstract: Troglitazone has recently been introduced in the treatment of Type 2 diabetes. In addition to its anti-diabetic effects it acts as a perixosome proliferator activated receptor-gamma (PPAR-gamma) agonist and has anti-inflammatory properties by inhibiting macrophage tumour necrosis factor-alpha (TNF-alpha) secretion. It also inhibits the production of endothelial selectin (e-selectin). Troglitazone also reduces interleukin-1alpha induced nitric oxide production in pancreatic beta-cells, which may be relevant in preventing nitric oxide mediated damage to these cells in the Type 1 diabetes process. We tested troglitazone in the spontaneous model of autoimmune diabetes, the non-obese diabetic (NOD) mouse, to determine its effect on the disease process. When administered by gavage from weaning at a dose of 400 mg/kg body weight (n = 32), troglitazone reduced the incidence of diabetes by 16 weeks compared to controls (n = 32) in a pattern that was maintained up to the conclusion of the experiment at 31 weeks of age (p < 0.05). Insulitis was unaltered (index = 1.05 +/- 0.71 vs. 1.13 +/- 0.82, treated vs. controls, p = 0.78). The study was repeated using troglitazone in the diet of NOD mice (n = 24) to give a dose of approximately 200 mg/kg body weight in order to provide a more consistent level of troglitazone during the time course of the experiment. There was a reduction of diabetes incidence in this group but it did not reach significance. Insulin levels were reduced in gavage treated mice although such reduction did not reach significance (p < 0.07). We conclude that, in view of its effect on this model of autoimmune diabetes and because of its known function as an insulin sensitiser, troglitazone might be considered for potential use in those patients with Type 1 masquerading as Type 2 diabetes.
Abstract: We evaluated the role of first (131)I-whole-body scan and of first serum thyroglobulin (Tg) measurement after surgery in the early diagnosis of metastases from differentiated thyroid carcinoma (DTC). METHODS: In 269 patients with metastases from DTC, we retrospectively evaluated the results of first whole-body scan (performed 40 days after surgery with diagnostic or therapeutic (131)I dose) and in 69 of them we also evaluated the result of first Tg measurement (performed the day before the first whole-body scan) in relation to the presence, localization and type of metastases. RESULTS: In all patients, the first whole-body scan was positive for the thyroid remnant, and in 54.3% of patients it was also positive for metastases. In the remaining 45.7% of patients, metastases were detected during the follow-up. First Tg levels were >60 ng/ml in 66.7% of patients with metastases. First whole-body scan detected metastases in 47.8% of patients with Tg values <60 ng/ml, while Tg values were >60 ng/ml in 61.3% of patients with first whole-body scan negative for metastases. The combined results of both first whole-body scan and first Tg measurement allowed the early detection of metastases in 82.6% of patients. Whole-body scan detected distant metastases more frequently than local lymph node metastases (p < 0.01). CONCLUSION: In more than 80% of patients, metastases were suspected or diagnosed as early as 40 days after surgery in the presence of residual thyroid tissue by combined evaluation of results of first whole-body scan and Tg measurement.
Abstract: Insulin-dependent type 1 diabetes (IDDM) is caused by the autoimmune destruction of insulin-producing beta cells. Approximately 10%-20% of patients may benefit from adjuvant immunotherapy upon diagnosis of the disease in order to protect residual beta-cell function. It has been suggested that this subgroup of patients differs from others by virtue of the presence of residual pancreatic inflammation and beta-cell function. In this study we have investigated to what extent technetium-99m-labelled human polyclonal immunoglobulins (99mTc-HIG) accumulate in the pancreas of IDDM patients at the time of diagnosis and 1 year thereafter, with a view to ascertaining whether HIG scintigraphy is useful for the identification of IDDM patients with residual pancreatic inflammation. Patients with recent-onset IDDM (n=15) were investigated at the time of diagnosis and 1 year later, and ten age- and sex-matched normal subjects were also studied. Gamma camera imaging and target to background ratio, analysed blind by three independent readers, were used to quantify the radioactivity in the pancreatic region and findings were correlated with metabolic, immunological and clinical parameters. Seven out of 15 newly diagnosed IDDM patients showed a significant accumulation of radiolabelled HIG in the pancreas (pancreas/bone ratio higher than the mean +2SD of normal subjects). One year after diagnosis, pancreatic accumulation of HIG was still detectable in most IDDM patients who were positive at the time of diagnosis. Six out of seven patients with positive scintigraphy had a partial clinical remission. These results indicate that HIG scintigraphy at the time of onset of diabetes identifies a subset of patients with residual beta-cell function who may benefit from adjuvant immunotherapy.
Abstract: The non-obese diabetic (NOD) mouse is widely used to study the pathogenesis of insulin-dependent diabetes mellitus. However, the mechanisms responsible for beta-cell destruction, in this model, are still poorly defined. The CD95/CD95L system among other effector systems has been implicated in beta-cell death. In this study we investigated in NOD, non-obese resistant (NOR) and Balb/c mice the expression of CD95 and CD95L in alpha and beta pancreatic cells by immunohistochemistry and immunofluorescence. We demonstrate that alpha cells in the islets of Langherans constitutively express CD95L forming a natural shield around beta cells.
Abstract: Recent advances in our understanding of the pathophysiology of inflammatory processes at the molecular level, combined with progress in radiopharmaceutical sciences, has boosted the development of nuclear medicine techniques for the diagnosis of infection/inflammation. The use of radiolabelled white blood cells has been studied and evaluated in several pathologies and is still the reference method. Several alternative approaches, however, have been developed that may, in the future, improve the specificity and the ease of use of the technique. For the first time, a radiopharmaceutical that may distinguish between sterile and septic inflammation, 99Tcm-Infecton, has been developed. Also, monoclonal antibody fragments, cytokines and a variety of new synthetic peptides that bind specifically to granulocytes have been prepared. Particularly promising appears to be the detection of the expression of adhesion molecules by activated endothelium as a first-line technique for the detection of inflammatory foci. For the diagnosis of autoimmunity and chronic inflammatory processes, important progress has also been made. Autoimmunity can now be studied by in vivo detection of tissue-infiltrating activated lymphocytes by radiolabelled interleukin-2. A radiopharmaceutical for the diagnosis of monocyte infiltration, J001X, is also available, and the commercially available Octreoscan holds promise in autoimmune and chronic inflammatory diseases. The efforts of the scientific community have given us new perspectives in diagnostic nuclear medicine: easier techniques that promise better sensitivity and specificity are now also being tested for the study of new disease conditions. The results of the clinical trials now in progress will determine the future of this challenging and fascinating field and the role of nuclear medicine in the management of patients with infection/inflammation.
Abstract: In insulin-dependent (type 1) diabetes mellitus, increasing peripheral insulin sensitivity might be a useful approach in controlling the process leading to beta cell destruction by reducing insulin output and thereby reducing the antigenicity associated with its release. The aim of this study was to investigate whether the use of a biguanide, Metformin, which has been suggested to increase insulin sensitivity, was capable of modifying the natural history of diabetes in a model of type 1 diabetes, the non-obese diabetic (NOD) mouse. Using age-, sex- and litter-matched groups, three groups of 32 animals each were treated with Metformin in their drinking water at a high dose of 200 mg/kg body weight and at a low dose of 20 mg/kg body weight; the third group of mice acted as controls. Diabetes incidence at 30 weeks of age was similar in all groups. No significant differences in the calculated index of insulitis were observed in treated or control animals. We conclude that Metformin does not affect the disease process leading to clinical diabetes in this animal model.
Abstract: We describe here a new method for labelling interleukin-2 (IL-2) in high specific activity with 99mTc for in vivo studies in man. Labelling was performed via a two-step reaction using an N3S bifunctional chelating agent. To optimise the reaction, factors affecting the incorporation of 99mTc into the N3S ligand were studied. The conjugation of the preformed N3S chelate ligand to IL-2 was then similarly optimised. Various strategies for purifying the 99mTc-IL-2 were explored including size-exclusion, ion-exchange, and several modes of reversed-phase chromatography. The radiochemical purity of the purified protein was determined by HPLC, ITLC, TCA precipitation, and SDS-PAGE. The receptor binding capacity of 99mTc-IL-2 was studied. Biodistribution studies in normal mice were performed with 99mTc-IL-2 purified using different techniques or labelled after prolonged storage and compared to 125I-IL-2.
Abstract: OBJECTIVE: Protection of residual beta cell function at the time of diagnosis of insulin-dependent diabetes mellitus (IDDM) by intensive insulin therapy and the addition of nicotinamide (NA) has been established. The objective of this study was to evaluate the effect of a free oxygen radical scavenger such as vitamin E (Vit E) on residual beta cell function and parameters of metabolic control in patients with recent onset IDDM undergoing intensive insulin therapy. DESIGN: The effect of Vit E was compared with that of NA (control group) in a randomized multicentre trial. METHODS: Eighty-four IDDM patients between 5 and 35 years of age (mean age 15.8 +/- 8.4 (s.d.) years) entered a one year prospective study. One group of patients (n = 42) was treated with Vit E (15 mg/kg body weight/day) for one year; the other group (n = 42) received NA for one year (25 mg/kg body weight/day). All patients were under intensive insulin therapy with three to four injections a day. Basal and stimulated (1 mg i.v. glucagon) C-peptide secretion, glycosylated haemoglobin and insulin dose were evaluated at diagnosis and at three-monthly intervals up to one year. RESULTS: Preservation and slight increase of C-peptide levels at one year compared with diagnosis were obtained in the two treated patient groups. No statistically significant differences were observed in basal or stimulated C-peptide levels between the two groups of patients for up to one year after diagnosis. Glycosylated haemoglobin and insulin dose were also similar between the two groups; however patients receiving Vit E under the age of 15 years required significantly more insulin than NA-treated patients one year after diagnosis (P < 0.04). CONCLUSIONS: Our data indicate that Vit E and NA possess similar effects in protecting residual beta cell function in patients with recent onset IDDM. Since their putative mechanism of protection on beta cell cytotoxicity is different, combination of these two vitamins may be envisaged for future trials of intervention at IDDM onset.
Abstract: OBJECTIVE: The possibility to quantify in vivo the severity of the inflammatory process in the pancreas of patients with recent onset insulin dependent diabetes mellitus (IDDM) could be of great relevance for follow-up studies involving immunotherapy. Scintigraphy with radiolabelled human polyclonal immunoglobulins (99mTc-HIG) is currently used for the diagnosis and follow-up of several acute and chronic inflammatory diseases. In this longitudinal study we have investigated to what extent 99mTc-HIG accumulate in the pancreas of patients with recent onset IDDM and in subjects at risk to develop IDDM. METHODS: Combined computerised tomography and gamma camera imaging were used to measure the radioactivity in the pancreatic region, as the pancreas/bone radioactivity ratio (P/B). Patients with IDDM (n = 15) were investigated at the time of diagnosis and after 1 year. Five pre-diabetic ICA+ve subjects and 8 age and sex matched normal subjects were also investigated. RESULTS: Eight out of 15 newly diagnosed IDDM patients and 2/5 ICA+ve subjects showed a significant accumulation of radiolabelled HIG in the pancreas (P/B higher than the upper 1st centile of normal subjects). One year after the diagnosis a significant accumulation of immunoglobulins was still detectable in the pancreas of IDDM patients positive who were positive at diagnosis. CONCLUSIONS: These results suggest that immunoglobulins home and bind to the pancreas of patients with recent onset IDDM and also in some ICA+ve individuals. This may reflect an increased vascular permeability of pancreatic capillaries as a consequence of the inflammatory process involving the islets. Thus, this technique may be useful for monitoring the efficacy of immune intervention at diagnosis.
Abstract: We previously reported that metformin improves insulin-mediated glucose liver metabolism in patients with non insulin dependent diabetes (NIDDM). It is not clear whether this is a direct effect of metformin on liver metabolism or mediated by other mechanisms such as increased liver blood flow. In this respect it has recently been reported that metformin increases hepatic blood flow (HBF) in diabetic rats. The aim of this study was to evaluate whether the administration of metformin is associated with modifications in HBF in humans. Patients affected by NIDDM (n = 11) and normal subjects (n = 6) were studied. In the first protocol HBF was investigated in six overweight (BMI 27 +/- 2 Kg/m2) NIDDM patients and six normal subjects (age and BMI matched) already on metformin treatment before and 2 h after the administration of 500 mg metformin. In the second protocol HBF was investigated in obese (BMI 32 +/- 1 Kg/m2) NIDDM patients (n = 5) in good metabolic control before and after 15 days of metformin at the dose of 1 g daily. HBF was measured by intravenous injection of 3 mCi 99mTc-phytate. In both protocols no significant changes in HBF were observed following metformin administration either in NIDDM patients or normal subjects. No significant differences were observed in HBF between diabetic patients and normal subjects. These data indicate that metformin has no effect on HBF in man. The previously reported improvement of insulin mediated liver metabolism induced by metformin is likely to be a consequence of the direct effect of the drug at hepatocyte level which is independent of HBF modifications.
Abstract: Radiolabelled autologous low density lipoprotein (LDL) has previously been used to study in vivo distribution and metabolism of native-LDL. Non-invasive imaging of atherosclerotic lesions using 99mTc-LDL was shown to be feasible in animal models and patients but the clinical utility remains to be assessed. Since recent reports suggest that oxidized LDL may play a major role in the pathogenesis of atherosclerosis, we developed a technique to oxidize autologous LDL and compared the biodistribution of oxidized-LDL with that of native-LDL in man. In addition, we evaluated the uptake in vivo of oxidized- and native-LDL by atherosclerotic plaques. LDL, obtained from human plasma was treated with various combinations of copper ions and H2O2 to induce oxidative modification by increasing the content of lipid peroxidation products and electrophoretic mobility. When LDL (0.3 mg/ml) was incubated with 100 microM Cu2+ and 500 microM H2O2 oxidation occurred rapidly within 1 h, and was labelled with 99mTc efficiently as native LDL. In vivo distribution studies revealed a faster plasma clearance of oxidized-LDL compared to native-LDL, and a higher uptake by the reticuloendothelial system. Tomographic scintigraphy of the neck in patients suffering from transient ischemic attacks, revealed accumulation of radiolabelled LDL preparations in the carotid artery affected by atherosclerotic lesions. We developed a technique to rapidly oxidize LDL using copper and H2O2. Biodistribution data demonstrate that oxidized-LDL is rapidly cleared from circulation, is taken up mostly by organs rich in macrophages, and can be detected at the level of carotid plaques.
Abstract: Nicotinamide has been recently introduced, in addition to intensive insulin therapy for patients with recent-onset insulin-dependent diabetes mellitus (IDDM) to protect beta cells from end-stage destruction. However, available data are conflicting. A double blind trial in 56 newly-diagnosed IDDM patients receiving nicotinamide for 12 months at a dose of 25 mg/kg body weight or placebo was designed in order to determine whether this treatment could improve the integrated parameters of metabolic control (insulin dose, glycated haemoglobin and C-peptide secretion) in the year after diagnosis. In addition to nicotinamide or placebo, patients received three to four insulin injections daily to optimize blood glucose levels. Patients treated with nicotinamide or placebo received similar doses of insulin during follow-up and 1 year after diagnosis with comparable glycated haemoglobin levels 6.7 +/- 1.8% nicotinamide vs 7.1 +/- 0.6% placebo). Basal and glucagon stimulated C-peptide secretion detectable at diagnosis were similarly preserved in the course of 12 months follow-up both in nicotinamide and placebo treated patients. No adverse effects were observed in patients receiving nicotinamide. When age at diagnosis was taken into account, nicotinamide treated older patients ( > 15 years of age) showed significantly higher stimulated C-peptide secretion than placebo treated patients (p < 0.02). These results suggest that nicotinamide can preserve and improve stimulated beta-cell function only in patients diagnosed after puberty.(ABSTRACT TRUNCATED AT 250 WORDS)
Abstract: Partial recovery of beta-cell function in type 1 diabetes is common after diagnosis by intensive insulin therapy. Residual beta-cell function can be improved by other therapies. Cyclosporin (CyA) and nicotinamide (NA), alone or in combination, can preserve this function, as indicated by the parameters of metabolic control (insulin dose, HbA1C). After suspension of CyA, insulin requirement returns to control values, suggesting loss of residual beta-cell function. The effects induced by withdrawal of NA after 1 year are not known. For the first time, we studied 27 type 1 diabetes patients treated with NA for 12 months and then followed up for 1 year after discontinuance of NA. Another 25 patients treated with NA + CyA and 28 control patients were followed up similarly. Insulin requirement doubled 12 months after discontinuance of NA or NA + CyA, becoming identical to that of controls. As patients showed HbA1C values similar to control subjects, it is likely that beta-cell function deteriorated after discontinuance of therapy. As NA is safer than other agents and its effects are beneficial, longer studies are warranted to investigate NA in prolonged treatments since this compound is also being considered for prevention of type 1 diabetes.
Abstract: This review examines the association between retroviruses and diabetes in the mouse model, the role of retroviruses in the pathogenesis of Type 1 diabetes and the mechanisms by which retroviruses can induce an autoimmune reaction. Three putative mechanisms are considered: the expression of retroviral protein(s) on the beta-cell surface as the first step in immune response against beta cells; the homology of a retroviral product with a self antigen inducing a cross-reacting autoimmune response (molecular mimicry); and a retroviral product showing homology with interleukin-2 and inducing T-cell activation against beta-cell antigens and loss of tolerance. These findings are discussed for their possible implications in the pathogenesis of human Type 1 diabetes.
Abstract: We evaluated the sensitivity of 111In-Octreotide scintigraphy in the diagnosis of pancreatic insulinoma in a selected number of patients. In addition, we compared the results of scintigraphy with those of other conventional diagnostic techniques. Seven patients with surgically confirmed insulinoma (< 1.5 cm in diameter) of the pancreas were studied. Before surgery, patients underwent arteriography with Ca-gluconate, CT scan, and 111In-Octreotide scintigraphy. 111In-Octreotide scintigraphy showed a higher diagnostic specificity (85%) than selective arteriography (83%) or CT scan (57%). We conclude that 111In-Octreotide scintigraphy should always be performed before surgery in cases of pancreatic insulinoma and that a SPECT acquisition should be performed both 6 and 24 hours post-injection in order to increase the diagnostic sensitivity of the test.
Abstract: We have investigated the presence of somatostatin receptors on the cell surface of metastatic medullary thyroid carcinoma in vivo using 111In-Octreotide scintigraphy. Five patients were studied before and three months after therapy with octreotide (300-600 micrograms/day). After each 111In-Octreotide scintigraphy the target/background (T/B) radioactivity ratio was calculated for each detectable metastases. A total of 14/18 metastases showed a reduction in the T/B ratio after therapy, suggesting saturation or down-regulation of the somatostatin receptors on metastases induced by octreotide therapy. Patients also showed a reduction in serum calcitonin levels after therapy. We conclude that 111In-Octreotide scintigraphy may be useful in medullary thyroid carcinoma to evaluate the rationale for somatostatin therapy and to monitor the effect of treatment.
Abstract: Non-obese diabetic (NOD) mice spontaneously develop an autoimmune diabetes with higher incidence in females than in males. In order to elucidate possible factors involved in the different incidence of diabetes between male and female mice, we studied the progression of pancreatic beta-cell loss in relation to mononuclear cell infiltration of the pancreas (insulitis). We examined the pancreas of 76 NOD mice (39 males and 37 females) of different ages. The beta-cell content was assessed by immunoperoxidase staining of sections with an anti-insulin serum and the severity of insulitis was determined by haematoxylin staining of the same sections. A semi-quantitative criterion was used to grade both parameters. The results showed that females have a faster loss of beta-cell mass, which progressively decreases with the increase of severity of insulitis. In males, a medium to severe degree of insulitis is required before initial loss of beta cells occurs. Under the age of 10 weeks there was a significantly lower content of beta cells in females than males (2.84 +/- 0.03 vs 2.67 +/- 0.07; P = 0.02). Since we never observed a significant difference in the degree of mononuclear cell infiltration in age-matched males and females, these data support the hypothesis of weaker beta-cell resistance to immunological attack in female mice. Thus beta-cell sensitivity, in addition to immunological activity, is an important factor in the pathogenesis of insulin dependent diabetes.
Abstract: A 1-year open randomized controlled multicentre trial was carried out on 90 patients with recent onset (< 4 weeks) insulin-dependent diabetes (IDDM) to compare the effect of nicotinamide (NCT) with the combination NCT and low dose cyclosporin (CyA) on clinical remission and optimization of metabolic control during the first year from diagnosis. Three groups of patients were randomly assigned to receive for 12 months either NCT 25 mg kg-1 day-1 (n = 30) or NCT 25 mg kg-1 day-1 + CyA 5 mg kg-1 day-1 (n = 30), the latter adjusted to maintain 12 whole blood trough levels of 83 nmol l-1; a third group of patients (n = 30) receiving insulin only acted as a control group for spontaneous remission and metabolic control. Clinical remission (i.e. suspension of insulin therapy with normal metabolic parameters for more than 2 weeks according to the International Diabetes Immunotherapy Group) was achieved at 3 months in 6/30 NCT treated patients and in 1/30 NCT + CyA treated patient (p = 0.05); no remission was observed in control patients. At 6 months the number of patients achieving remission in each group was 4/29, 3/27, and 1/29, respectively (p = NS). One year after diagnosis 4/27 NCT treated, 2/25 NCT+CyA treated but 0/28 of the control patients were in remission (NCT vs control p = 0.05). Clinical remission lasted longer (7 +/- 3 SD months) in NCT treated patients than in NCT+CyA treated or control patients (p < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)
Abstract: OBJECTIVE--The aim of this study was to compare the effect of nicotinamide (NCT) alone or in combination with a cortisone-like substance, deflazacort (DFL), on the integrated parameters of metabolic control in patients with the recent-onset of insulin-dependent diabetes mellitus (IDDM). RESEARCH DESIGN AND METHODS--Thirty-six patients who were diagnosed with diabetes between 5 and 35 years of age entered a randomized, double-blind, 1-year prospective study. Group A (n = 18) received NCT for 1 year (25 mg.kg-1.day-1) plus DFL for 3 months (0.6 mg.kg-1.day-1 in the first month, 0.3 mg.kg-1.day-1 in the other 2 months). Group B (n = 18) received NCT for 1 year (25 mg.kg-1.day-1) plus placebo for the first 3 months. All patients were treated with intensified insulin therapy. RESULTS--At 3 months after diagnosis, the insulin dose was significantly higher in group A compared with group B (P < 0.03) with similar HbA1 levels. Basal and stimulated C-peptide levels in group A of both adults and children were significantly higher compared with patients of group B (P < 0.05 and P < 0.03, respectively). At the end of a 1-year follow-up, basal C-peptide did not differ between the two groups, although stimulated C-peptide was still significantly higher in patients of group A compared with group B (P < 0.05). Finally, insulin requirement did not differ between the two groups. CONCLUSIONS--A short-term course of DFL therapy at diagnosis in addition to NCT slightly increases glucagon-stimulated but not basal beta-cell function after 1 year.
Abstract: Insulitis is considered the histopathological hallmark of type I (insulin-dependent) diabetes. In the non-obese diabetic (NOD) mouse, diabetes has never been observed in the absence of insulitis. The in vivo detection of insulitis could be of relevance for early prediction of diabetes. As approximately 15% of islet-infiltrating lymphocytes express interleukin 2 receptors, we have labelled recombinant interleukin 2 with 123I and used this radiopharmaceutical to detect insulitis by gamma camera imaging. We studied 71 prediabetic NOD and 27 normal Balb/c mice. Labelled alpha-lactalbumin was used as the control protein. In the first set of experiments we studied the tissue distribution of radiolabelled interleukin 2 in isolated organs from animals sacrificed at different time points. Higher radioactivity was detected in the pancreas of NOD mice injected with labelled interleukin 2, as compared to NOD mice receiving labelled alpha-lactalbumin (p < 0.003 at 20 min: p < 0.001 at 40 min; p < 0.001 at 60 min) or Balb/c mice injected with labelled interleukin 2 (p < 0.05 at 40 min; p < 0.001 at 60 min). In another set of experiments, gamma camera images have been acquired after injection of 123I-labelled interleukin 2. Radioactivity in the pancreatic region of prediabetic NOD and Balb/c mice showed similar kinetics to those observed by single organ counting, with higher accumulation in the pancreatic region of NOD mice (p < 0.04 after 22-45 min in NOD mice vs Balb/c mice).(ABSTRACT TRUNCATED AT 250 WORDS)
Abstract: Non-obese diabetic (NOD) mice are commonly used in autoimmune research. However, the diversity of these mice in developing autoimmune disease under different conditions prompted a group of researchers to compile a questionnaire on this subject. Here Paolo Pozzilli and colleagues comment on the results of this survey.
Abstract: It has been suggested that heparin and its analogues may have a suppressive effect on the immune response by interfering with T-lymphocyte heparinase activity, thus altering the ability of T-lymphocytes to penetrate the extracellular matrix and migrate to target tissues. We have investigated whether a heparin analogue (ITF-5005) can alter lymphocytic infiltration of the endocrine pancreas (insulitis) and/or diabetes incidence in the non-obese diabetic (NOD) mouse. Sixty-four NOD mice were divided at weaning and injected subcutaneously five times per week with either 18, 36 or 72 micrograms/kg body weight of ITF-5005 or saline as a control. At 12 weeks of age, the animals were culled and their pancreata sectioned, stained and assessed 'blind' for insulitis and insulin containing cells. Insulitis was similar in all groups as was the proportion of insulin-containing cells. To determine the effect on diabetes incidence, two groups of mice were injected with either saline or 140 micrograms/kg body weight of ITF-5005 from weaning until 30 weeks of age. No difference was found in overall diabetes incidence; however, disease onset was significantly accelerated in the treated group. We conclude that ITF-5005, at the doses employed, has no effect on insulitis or the proportion of treated group. We conclude that ITF-5005, at the doses employed, has no effect on insulitis or the proportion of insulin-containing cells found in the pancreas, but that it can accelerate the course of diabetes in the NOD mouse.
Abstract: The functional state of beta cells may influence the rate of their destruction in Type 1 (insulin-dependent) diabetes mellitus. We examined the effect of diazoxide, which inhibits insulin secretion, or tolbutamide, which stimulates insulin secretion, upon the incidence of diabetes in the non-obese-diabetic (NOD) mouse. Female mice were treated from 3-30 weeks of age with diet containing diazoxide 250 mg.kg-1 or tolbutamide 125 mg.kg-1. The cumulative incidence of diabetes at 35 weeks was similar in the diazoxide (16 of 24) and control (18 of 24) groups, but reduced in the tolbutamide group (10 of 23, p < 0.04 vs control group). In a second experiment, treatment was started from 9 weeks of age, by which time insulitis is already present. The cumulative incidence of diabetes at 35 weeks was 16 of 24 in controls, 15 of 24 on diazoxide and 11 of 24 on tolbutamide (p = NS vs control). A third experiment compared the effect of treatment from 3 weeks with control diet or diet containing tolbutamide 125 mg.kg-1 or 500 mg.kg-1. Diabetes was reduced by tolbutamide treatment, with a cumulative incidence of 25 of 31 in controls, 18 of 30 on tolbutamide 125 mg.kg-1 (p < 0.04) and 14 of 32 on 500 mg.kg-1 (p < 0.002), although the difference between the two treatment groups failed to reach statistical significance. A fourth experiment showed that treatment from 3-12 weeks with diazoxide 1000 mg.kg-1 increased the extent of insulitis compared with controls and animals treated with tolbutamide 500 mg.kg-1.(ABSTRACT TRUNCATED AT 250 WORDS)
Abstract: We have developed a flow cytometric method to evaluate the binding of interleukin-2 analogues to receptors. The method relies on competition for binding between a fluorescein-conjugated monoclonal antibody (MoAb) directed against the human interleukin-2 receptor alpha chain (fluorescein isothiocyanate (FITC) anti-IL-2R) and the test protein. IL-2R positive cells are incubated with FITC-anti-IL-2R MoAb in the presence of native IL-2 or IL-2 iodinated by either the chloramine-T or the lactoperoxidase-glucose-oxidase method. The binding of IL-2 is indicated by decreased fluorescence. This method is suitable for measuring the binding capacity of modified IL-2 molecules and avoids the need for radioactive tracers. It provides a simple and reproducible technique, which can be extended readily to the study of the receptor binding capacity of cytokines conjugated with toxins, drugs or other molecules.
Abstract: The labelling of interleukin-2 (IL-2) with 123I and its in vivo application for imaging chronic pathological lymphocytic infiltrations are described. The lactoperoxidase/glucoseoxidase technique was the labelling method of choice leading to immunoreactive IL-2 with high specific activity. Labelled IL-2 was injected in diabetes-prone non-obese diabetic (NOD) mice with pancreatic lymphocytic infiltration. As control animals, Balb/c mice were used. As specificity control, monoclonal antibodies AMT13 and UCHT1, bovine serum albumin and alpha-lactalbumin were radioiodinated and injected in mice. Eighteen NOD mice and four control Balb/c mice were used for gamma camera imaging experiments. Fifty-four NOD and 20 Balb/c mice were used for time course single organ counting and autoradiography. Gamma camera images showed that radioactivity accumulated in the pancreatic region from the 10th minute onwards in NOD mice injected with 123I-IL-2 but not in Balb/c mice, or in NOD mice injected with control radiopharmaceuticals. These findings were confirmed by counting the radioactivity present in single organs. Autoradiography of NOD pancreas, after injection of labelled IL-2, showed that radioactivity was specifically associated with infiltrating lymphocytes. In conclusion, this technique is highly specific and easy to perform and we suggest its application in humans for in vivo detection of areas of lymphocytic infiltration.
Abstract: Ciamexon (CMX), a new immunomodulatory compound acting mainly on B-lymphocytes was given orally to 42 NOD mice divided into three sex and litter matched groups (A: 0.3 mg/mouse/day CMX, B: 1.5 mg/mouse/day CMX, C: control) from 7 weeks of age. Animals were followed up for evaluation of diabetes incidence up to 32 weeks of age. There was a tendency for a delayed onset of hyperglycemia in mice of group B up to 26 weeks of age; however no significant difference in the cumulative incidence of diabetes at 32 weeks of age was observed (A: 57.5%, B: 38.5%, C: 38.5%). No differences were found in the number of infiltrated islets in animals culled at 10 weeks of age treated with CMX from 4 weeks of age. We conclude that CMX does not modify the course of insulitis and diabetes incidence in NOD mice although though the appearance of glycosuria was delayed by this treatment.
Abstract: Tenidap, a novel compound inhibiting cyclooxygenase and lipoxygenase, also possessing an inhibitory effect on interleukin-1 secretion by in vitro activated macrophages, has been administered to the non obese diabetic (NOD) mouse to evaluate its action on the induction and progression of insulitis and the diabetes incidence. Animals were allocated to three groups (group A: control group; group B: 12 mg/kg/day Tenidap; group C: 36 mg/kg/day Tenidap); female animals only were followed up to investigate the effect on diabetes incidence. The administration of Tenidap influenced the natural course of insulitis in male NOD mice; thus, at 60 and 100 days of age the mean percentage of infiltrated islets was significantly reduced compared to control animals (p less than 0.02). Moreover the severity of lymphocytic infiltration at 60 days of age was reduced in male mice of group B and C compared to control mice (p less than 0.004 and p less than 0.0001, respectively) whereas at 100 days of age this difference was not significant. However the progression towards severe insulitis in male animals receiving Tenidap was halted compared to control animals. Tenidap had also a significant dose dependent effect at 60 days on the severity of lymphocytic infiltration (group B vs. group C, p less than 0.01). By contrast, this agent had no effect on the degree of insulitis and diabetes incidence in female NOD mice. In both sexes at the end of follow-up a significant reduction in body weight was observed in animals of Group C compared to control animals (p less than 0.002).(ABSTRACT TRUNCATED AT 250 WORDS)
Abstract: This study compared serum thyroglobulin measurement and whole-body scans in the post-surgical follow-up of patients with differentiated thyroid carcinoma. Thyroglobulin levels were measured in 61 patients receiving L-thyroxine therapy after thyroidectomy, and again after suspension of therapy, before performing a whole-body scan with iodine-131. The sensitivity, specificity, and accuracy of thyroglobulin levels, measured during L-thyroxine therapy, for diagnosis of tumor residue or metastases were then calculated and compared with results obtained by diagnostic whole-body scanning. Our data show that neither thyroglobulin levels nor whole-body scans alone can discriminate between patients with or without metastases. Sensitivity reached 95.7%, specificity 100%, and accuracy 96.7% if results of both procedures were also taken into consideration. We conclude that in the management and follow-up of patients with differentiated thyroid carcinoma both parameters need to be evaluated.
Abstract: An association between the incidence of childhood Type 1 (insulin-dependent) diabetes mellitus and the average yearly temperature in different countries has been reported, the incidence being higher in countries with a lower mean temperature. We have studied the effect of environmental temperature on the incidence of diabetes in an animal model of Type 1 diabetes, the non-obese diabetic (NOD) mouse. Female NOD mice were divided at weaning, with one group placed at a higher temperature (mean 23.7 +/- 1.7 degrees C) and the other at a lower temperature (21.0 +/- 1.8 degrees C). At 20 weeks of age 6 of 16 mice at lower temperature and 1 of 17 mice at higher temperature had developed diabetes (p less than 0.02); at 30 weeks 10 of 16 and 5 of 17 mice had developed diabetes (p less than 0.05). Non-diabetic animals in the low temperature group had a higher food intake than those in the high temperature group between 13-15 weeks of age (28.0 +/- 1.2 g/week vs 24.8 +/- 0.7 g/week, p less than 0.05). In a parallel experiment, histological examination showed that there were similar degrees of insulitis in the high and low temperature groups at seven weeks of age. We conclude that environmental temperature can affect the incidence of diabetes in the NOD mouse and that this may be related to alterations in food intake.
Abstract: A longitudinal study of lymphocytic infiltration in the endocrine pancreas of non-obese diabetic mice was performed to investigate the role of different lymphocyte subsets in the pathogenesis of diabetes. The incidence of insulitis and the percentage of mononuclear cell subsets in the pancreas were evaluated in non-obese diabetic mice of various ages (5, 9, 13, 17, 22, 29 and 36 weeks). Cryostat sections of pancreas were stained with heamatoxilin-eosin or with different monoclonal antibodies against total T lymphocytes, helper T lymphocytes, cytotoxic/suppressor T lymphocytes, activated interleukin 2 receptor positive lymphocytes and B lymphocytes. A monoclonal antibody against Class-II antigens was also used. Positive cells were revealed by the immunoperoxidase technique. Insulitis was found in 5 weeks old mice but to a lesser extent than in adult animals. No significant variation between infiltrating cell subsets was found in different age groups. T lymphocytes ranged between 20.4% and 28.1%, B lymphocytes between 28.8% and 30.8% and Class-II positive cells between 22.8% and 32.2%. Interleukin 2 receptor positive cells ranged between 5.5% and 8.5% as detected with AMT-13 monoclonal antibody which recognise the interleukin 2 binding site. A higher percentage of activated cells was observed using another monoclonal antibody (7D4) directed against a different epitope of the interleukin 2 receptor, suggesting the presence of activated lymphocytes with interleukin 2 receptors saturated by interleukin 2. No insulin-containing cells were found to express Class-II molecules as demonstrated by a double immunofluorescence technique. Most infiltrating mononuclear cells were found to be positive for Class-II and L3T4 antigens or to be Class-II positive and express surface immunoglobulins.(ABSTRACT TRUNCATED AT 250 WORDS)
Abstract: Suitable animal models of human Type 1 (insulin-dependent) diabetes mellitus have long been sought, in particular a model that would permit detailed histological and immunological investigation of changes in the islet preceding the metabolic disorder. This would allow hypotheses as to pathogenesis of the condition to be examined and interventions such as immunotherapy to be tested. The most widely studied models include the low-dose streptozotocin induced diabetic mouse and the BB rat, but both differ in important respects from the human disease. In this review we describe one highly successful model, the non obese diabetic mouse. Selected aspects of pathogenesis and immunotherapy are presented and analogies with human Type 1 diabetes discussed.
Abstract: Radioactive tracer techniques using 131I- and 125I-insulin have been applied to study insulin metabolism. A simple method to label human insulin with 123I to a high specific activity is described. We have used this radiotracer to study insulin kinetics in vivo in normal subjects and in two groups of diabetic patients. The rate of decline in plasma radioactivity was shown to be significantly reduced in patients with diabetes. There were no significant differences in the time-activity profiles of liver and kidneys between the groups studied. This technique may provide insight into the mechanism of some forms of insulin resistance.
Abstract: The aberrant expression of Class-II molecules on pancreatic B cells in Type 1 (insulin-dependent) diabetes is still a matter of debate. In order to verify if Class-II molecules are expressed on islet cells in the NOD mouse we have studied 21 female mice of different ages (5 to 22 weeks). Serial cryostat pancreas sections were stained with monoclonal rat antibodies against Class-II antigens (P7/7) and the IL2 receptor (AMT-13). Our results show no Class-II expression by endocrine cells at any age, whereas about 25-32% of mononuclear cells infiltrating the islets were Class-II positive, and only 6-9% were IL2 receptor positive. No staining, except of occasional tissue macrophages, was observed in the pancreas of BALB/c, CBA or B10.SCSN mice. Our data are in contrast with those recently published and therefore the reality of expression of Class-II molecules by islet cells of NOD mice should be viewed with caution.
Abstract: Human recombinant interleukin-2 (IL-2) was labelled with Iodine-123 using modified Bolton and Hunter method. Separation from free iodine was performed by gel filtration chromatography using a Sephadex G10 column. HPLC analysis of labelled IL-2 showed that 98% of TCA precipitable radioactivity eluted in a single peak. The immunoreactivity of 123I-labelled IL-2 was determined by divert binding using the Fluorescence Activated Cell Sorter (FACS) and by receptor binding assay of IL-2 to activated lymphocytes. To demonstrate in vivo binding to activated lymphocytes, 123I-labelled IL-2 was injected intravenously into a newly diagnosed diabetic BB/Wistar rat. Higher radioactivity was detected in the pancreas and in the lymph nodes of the BB/W rat compared to a normal rat. These preliminary data show that 123I-labelled IL-2 retains its immunoreactivity and capacity to bind to activated lymphocytes both in vitro and in vivo and may be used for in vivo localization of lymphocytic infiltration in Type 1 diabetes.
Abstract: Recombinant interleukin-2 (IL2) was labelled with iodine-123 by a modified chloramine T method. The labelled IL2, which had a high specific activity (100-150 microCi/microgram) and retained its capacity for binding to the IL2 receptor on activated lymphocytes in vitro, was injected intravenously into BB/W diabetes-prone and normal rats. Combined immunoperoxidase staining and autoradiography of organ sections revealed that labelled IL2 bound specifically in vivo to IL2-receptor-positive cells in the spleen of both normal and BB/W rats and to activated lymphocytes infiltrating the pancreas of BB/W rats. The severity of lymphocytic infiltration correlated with the degree of radioactivity in the pancreas of BB/W rats. Time-activity curves, generated over organs of injected rats after gamma camera imaging, confirmed that radioactivity was greater in the pancreas of diabetes-prone than in normal rats. 123I is a suitable isotope for gamma camera imaging, so the intravenous injection of IL2 labelled with iodine-123 may be valuable for the in-vivo visualisation of activated lymphocytes in tissues infiltrated by lymphocytes.
Abstract: The history of a patient with a suspected ischemic brain infarct undergoing an indium-111-tropolone white cell labelled test is reported. The patient, who died 12 h after injection of the labelled cells, suffered of a brain haemorrhage. The post-mortem examination has allowed for the first time the measurement of radioactivity in different organs following the injection of indium-111-labelled leucocytes. High radioactivity was found only in tissues affected by inflammatory processes and in the lymphonodes draining the corresponding areas. This report clearly indicates the importance of this method for the study of white cell localization and circulation to the sites of infections.
Abstract: The circulating white blood cells of patients with brain infarction were labelled in vitro with Indium-111 tropolonate; the cells were reinjected to study the inflammatory process by gamma camera imaging. Eight patients with acute cerebral ischemic infarct were studied during the first two weeks after the onset of neurological symptoms. In seven cases a well defined area of increased radioactivity was revealed in the infarcted hemisphere indicating active migration and tracking of labelled leukocytes in cerebral infarct. This method allows monitoring of the cellular inflammatory response in human cerebral infarcts and adds another imaging technique.
Abstract: The purpose of this study was to compare the effect of indium oxine and indium-tropolone complexes (nonradiolabeled) on the function of isolated human lymphocytes. peripheral lymphocytes were obtained from 15 normal volunteers and incubated with indium oxine or indium tropolone according to the standard techniques currently used when cells are radiolabeled for subsequent in vivo studies. The phytohemagglutinin-induced (PHA) lymphocyte transformation and a more specific lymphocyte functional test (the mixed lymphocyte reaction) were performed following incubation with the indium complexes. The results indicate that PHA transformation is not affected by either indium oxine or indium tropolone, whereas both chelates reduced the mixed lymphocyte reaction. This suggests that these substances have a selective toxic effect only on a functionally distinct lymphocyte subset (i.e., the cytotoxic T cells) and indicates that there is no significant difference between the two indium chelates in terms of their effect on lymphocyte function.
Abstract: The diurnal variation of peripheral white cells and in particular of different lymphocyte subsets has been investigated in 11 normal subjects. Monoclonal antibodies (Mab) phenotyping total T lymphocytes (UCHT1), cytotoxic/suppressor (UCHT4), helper T cells (Leu 3a), B lymphocytes (231) and K/NK cells (H25) have been used. In addition to the traditional parametric statistics, the chronobiological approach of cosinor was adopted in order to inferentially obtain the waveform covering the 24-hr period. Cosinor analysis validated the existence of a significant rhythm for leucocytes (p = 0.04, lymphocytes (p = 0.03), and Leu 3a positive cells (p = 0.04). The best fitting period was equal to 28 hr. No circadian rhythm was documented for lymphocyte subsets positive for Mab UCHT4, 231, H25, by testing the variability with a frequency ranging from 1 cycle every 12hr to 1 cycle every 28 hr. By the non-inferential analysis of temporal curves, a significant peak of Leu 3a positive cells at 20.00 hr (p less than 0.001) was observed. The acrophase has been recorded by cosinor analysis at 20.36 hr. We conclude that the circadian variability of Leu 3a positive cell profile must be taken into account when the helper/suppressor ratio is calculated. The time-dependence of this lymphocyte subpopulation suggests that when therapy with corticosteroids is considered in autoimmunity, it should be planned by keeping the peak of Leu 3a positive cells as a marker time.
Abstract: Evidence has been accumulated that the anti-thyroid drugs used in the treatment of Graves' disease may have immunosuppressive properties but the exact mechanism of action is still unclear. In the present study, we have investigated the in vitro effect of carbimazole (CBZ) on the expression of lymphocyte differentiation antigens and on suppressor cell activity. The incorporation of radiolabelled methimazole (35S-MMI, the active metabolite of CBZ) by resting and mitogen stimulated lymphocytes was also investigated. CBZ at concentrations of 60 microM significantly inhibited the expression of the receptor for interleukin-2 (as defined by the anti-TAC monoclonal antibody [MoAb]) by lymphocytes stimulated with phytohaemagglutinin. The expression of an early activation antigen (as characterized by the 4F2 MoAb) was not affected. Twenty-four hour pre-incubation of cells with different concentrations of CBZ or medium alone did not change the lymphocyte response to mitogenic stimulation, thus suggesting no effect of the compound on suppressor cell function. Finally, there were no significant differences in the uptake of 35S-MMI between resting and stimulated lymphocytes. These data suggest that the immunosuppressive effect of CBZ may be due to its effect of reducing the expression of the receptor for interleukin-2 on lymphocytes undergoing full activation. This property of CBZ could be of relevance in the therapy of autoimmune thyroid diseases (not only Graves' disease) which are characterised by the presence of activated T cells in the thyroid and in circulation.
Abstract: Peripheral blood mononuclear cells have been investigated in 43 patients with Crohn's disease (CD) by means of a panel of 4 monoclonal antibodies (UCHT1, UCHT4, 4F2, 5E9). A decrease of total T cells (UCHT1+) (p less than 0.01) and a slight increase of cytotoxic/suppressor T cells (UCHT4+) were observed. Evidence of T-cell activation, as shown by the highly significant increase of 4F2+ and 5E9+ cells, was also found. The latter finding lends support to the concept that cell-mediated immune phenomena are an important feature in CD.
Abstract: Indium 111 oxine is currently used to label peripheral lymphocytes in order to study the kinetics of these cells in vivo. Since the quantity of radioisotope for labelling is still a matter of controversy, we have investigated in vitro the effect of increasing the concentration of indium 111 oxine on the lymphocyte surface phenotype and the antibody-dependent cellular cytotoxicity (ADCC) using lymphocytes from normal subjects. The cell surface phenotype, as evaluated by 2 monoclonal antibodies, was not affected whereas ADCC, at any of the doses used, was significantly reduced compared to the baseline value. The implications of these results for the use of indium 111 oxine for the in vivo studies are discussed.
