Dr. Renato Alberto Sinico Clinical Immunology Unit and Renal Unit Dept. of Medicine Azienda Ospedaliera Ospedale San Carlo Borromeo Via Pio Secondo, 3 20153 Milano Italy
Abstract: The objective of this study was to evaluate the clinical features, course, outcome, and prognostic indicators in lupus membranous nephritis (LMN) and to compare data of "pure" LMN vs "mixed" forms.
Abstract: T-helper type 2 responses are crucial in Churg-Strauss syndrome (CSS) and may enhance the production of IgG4 antibodies. The authors assessed the IgG4 immune response in CSS patients.
Abstract: The previously reported randomised controlled trial of a consensus regimen of pulse cyclophosphamide suggested that it was as effective as a daily oral (DO) cyclophosphamide for remission induction of antineutrophil cytoplasm autoantibodies-associated systemic vasculitis when both were combined with the same glucocorticoid protocol (CYCLOPS study (Randomised trial of daily oral versus pulse Cyclophosphamide as therapy for ANCA-associated Systemic Vasculitis published de groot K, harper L et al Ann Int Med 2009)). The study had limited power to detect a difference in relapse. This study describes the long-term outcomes of patients in the CYCLOPS study.
Abstract: Antineutrophil cytoplasmic antibodies (ANCA) are the serological hallmark of some idiopathic systemic vasculitides, such as granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA) and, to a lesser extent, Churg-Strauss syndrome (CCS), the so-called ANCA-associated vasculitides (AAV). ANCA were first detected by immunofluorescence (IIFT), subsequently the target antigens myeloperoxidase (MPO) and proteinase 3 (PR3) were identified, allowing the development of the quantitative, antigen-specific assays. According to the guidelines, combining IIFT and PR3-ANCA/MPO-ANCA assures the optimal diagnostic specificity. Antigen specificity does not effectively differentiate among the different AAV, however C-ANCA/PR3-ANCA are mainly found in GPA, while P-ANCA/MPO-ANCA are more prevalent in MPA and CSS. Despite their diagnostic value, the performance of the widespread immunometric assays for ANCA testing is disappointing, particularly for the low sensitivity. In recent years, more "sensitive" assays have been developed, using the microplate as well as fully the automated technologies, with promising preliminary results. ANCA, may be detected in a number of pathological conditions other than small vessel vasculitis. However, in most of these non-vasculitic patients ANCA do not recognize MPO or PR3 as target antigens, but other granulocyte components, often multiple or unknown specificities. A positive ANCA result by itself is not diagnostic for AAV, clinical evidence and possibly histological confirmation are always required. On the other hand, a negative test result cannot completely rule out a diagnosis of AAV, as AAV without detectable ANCA exist. The appropriate use of ANCA testing strongly improves the diagnostic accuracy and clinical usefulness of the results.
Abstract: Objectives. PTPN22 is involved in T-cell activation and its R620W single-nucleotide polymorphism (SNP) has been shown to predispose to different autoimmune diseases. The aims of this study were to investigate the role of the PTPN22 R620W SNP in conferring susceptibility to the ANCA-associated vasculitides (AAVs), and to explore potential associations between the PTPN22 genotype and the disease manifestations. Methods. PTPN22 R620W SNP was genotyped in a cohort of 344 AAV patients [143 with granulomatosis with polyangiitis (Wegener's) (GPA), 102 with microscopic polyangiitis (MPA) and 99 with Churg-Strauss syndrome (CSS)] and in 945 healthy controls. Results. The frequency of the minor allele (620W) was significantly higher in GPA patients than in controls [P = 0.005, χ(2 )= 7.858, odds ratio (OR) = 1.91], while no statistically significant association was found with MPA or CSS. Among GPA patients, the 620W allele was particularly enriched in ANCA-positive patients as compared with controls (P = 0.00012, χ(2 )= 14.73, OR = 2.31); a particularly marked association was also found with ENT involvement (P = 0.0071, χ(2 )= 7.258, OR = 1.98), lung involvement (P = 0.0060, χ(2 )= 7.541, OR = 2.07) and skin manifestations of all kinds (P = 0.000047, χ(2 )= 16.567, OR = 3.73). Conclusion. The PTPN22 620W allele confers susceptibility to the development of GPA (but not of MPA or CSS), and particularly of its ANCA-positive subset.
Abstract: Renal involvement is a common and often severe complication of anti-neutrophil cytoplasmic autoantibody (ANCA) associated vasculitides (AAV). With the exception of Churg-Strauss syndrome (CSS), where kidney involvement is not a prominent feature, renal disease is present in about 70% of patients with Wegener's granulomatosis, now called granulomatosis with polyangiitis (GPA) and in almost 100% of patients with microscopic polyangiitis (MPA). Kidney involvement is generally characterized by a pauci-immune necrotizing and crescentic glomerulonephritis with a very rapid decline of renal function (rapidly progressive glomerulonephritis). Even though there are not qualitative differences in glomerular lesions in patients with GPA or with MPA, chronic damage is significantly higher in MPA (and/or P-ANCA positive patients) than in GPA (and/or C-ANCA positive patients). If untreated necrotizing and crescentic glomerulonephritis has an unfavorable course leading in a few weeks or months to end stage renal disease. Serum creatinine at diagnosis, sclerotic lesions and the number of normal glomeruli at kidney biopsy are the best predictors of renal outcome. Corticosteroids and cyclophosphamide (with the addition of plasma exchange in the most severe cases) are the cornerstone of induction treatment of ANCA-associated renal vasculitis, followed by azathioprine for maintenance. Rituximab is as effective as cyclophosphamide in inducing remission in AAV and probably superior to cyclophosphamide in patients with severe flare, and could be preferred in younger patients in order to preserve fertility and in patients with serious relapses.
Abstract: The detection of anti-proteinase 3 (PR3) and anti-myeloperoxidase (MPO) autoantibodies represents a serological hallmark in the diagnosis of small vessel vasculitis such as granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA). We evaluated novel chemiluminescence assays (CIAs) for PR3- and MPO-ANCA detection and investigated their utility for disease activity monitoring.
Abstract: Granulomatosis with polyangiitis (Wegener's, GPA) is an uncommon disease of unknown etiology classically involves the ELK triad of the ear, nose, throat (E), lungs (L) and kidneys (K) with necrotizing granulomatous inflammation and vasculitis. Most of the initial symptoms begin in the head and neck region with a wide spectrum of involvement of any site ranging from the nasal septum, paranasal sinuses, oral mucosa, larynx and even the external, middle and internal ear. Diagnosis may be delayed because the onset is heterogeneous and sometimes limited to one organ. The pathologic findings of a characteristic inflammatory reaction pattern, and the serum findings of elevated antineutrophil cytoplasmic antibodies can help to establish the diagnosis. The differentiation from other conditions that mimic GPA such as lymphoma and infections is of critical importance to initiate appropriate treatment. Treatment of the underlying disease is medical with the use of immunosuppressive agents and will not be reviewed here. This review focuses on the otorhinolaryngologic manifestation and complication of GPA as well as their surgical management and specifies the role of the otorhinolaryngologist as an integral member of the multidisciplinary care team for patients with GPA.
Abstract: Autoantibodies to the non-collagen region (NC1) of the alpha-3 subunit of collagen IV represent a serological hallmark in the diagnosis of Goodpasture's syndrome (GPS). The objective of our study was to carefully analyze the performance characteristics of a novel anti-glomerular basement membrane (GBM) chemiluminescence immunoassay (CIA).
Abstract: BACKGROUND AND OBJECTIVES: The discovery of different podocyte autoantibodies in membranous nephropathy (MN) raises questions about their pathogenetic and clinical meaning. This study sought to define antibody isotypes and correlations; to compare levels in MN, other glomerulonephritides, and controls; and to determine their association with clinical outcomes. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Serum IgG(1), IgG(3), and IgG(4) against aldose reductase (AR), SOD2, and α-enolase (αENO) were measured at diagnosis in 186 consecutive MN patients, in 96 proteinuric controls (36 with FSGS, and 60 with IgA nephropathy), and in 92 healthy people recruited in four Italian nephrology units. Anti-phospholipase A2 receptor (PLA2r) and anti-neutral endopeptidase (NEP) IgG(4) were titrated in the same specimens. Association with 1-year follow-up clinical parameters was studied in 120 patients. RESULTS: IgG(4) was the most common isotype for all antibodies; IgG(1) and IgG(3) were nearly negligible. IgG(4) levels were positive in a significant proportion of MN patients (AR, 34%; SOD2, 28%; αENO, 43%). Antibody titers were higher in MN than in healthy and pathologic controls (P<0.005). Anti-NEP IgG(4) did not differ from normal controls (P=0.12). Anti-PLA2r IgG(4) was detected in 60% of patients and correlated with anti-AR, anti-SOD2, and anti-αENO IgG(4) (P<0.001). In MN patients negative for the whole antibody panel (20%), 1-year proteinuria was lower compared with patients with at least one antibody positivity (P<0.05). CONCLUSIONS: Our data suggest that IgG(4) is the prevalent isotype for antibodies against cytoplasmic antigens of podocytes (AR, SOD2, αENO). Their levels were higher than in other proteinuric glomerulonephritides and in normal controls and were correlated with anti-PLA2r. Only baseline negativity for all known antibodies predicted lower 1-year proteinuria.
Abstract: In Europe it is estimated that around 13million of adults (15-64years) have used cocaine at least once in their lifetime. The most frequently used route of administration for the drug is intranasal inhalation, or "snorting", and thus the adverse effects of cocaine on the nasal tract are very common. Habitual nasal insufflations of cocaine may cause mucosal lesions, and if cocaine use becomes chronic and compulsive, progressive damage of the mucosa and perichondrium leads to ischemic necrosis of septal cartilage and perforation of the nasal septum. Occasionally, cocaine-induced lesions cause extensive destruction of the osteocartilaginous structures of nose, sinuses and palate that can mimic other diseases such as tumors, infections, and immunological diseases. Thorough diagnostic workup, including endoscopic, radiologic, histopathologic and serologic testing is imperative to arrive at the proper diagnosis and to initiate appropriate local and systemic treatment. Positive antineutrophil cytoplasmic antibody (ANCA) test results may be found in an unexpectedly large proportion of patients with CIMDL. In several instances their lesions are clinically indistinguishable from granulomatosis with polyangiitis (Wegener's) limited to the upper respiratory tract. CIMDL seem to be the result of a necrotizing inflammatory tissue response triggered by cocaine abuse in a subset of patients predisposed to produce ANCA, particularly those reacting with HNE. The presence of these HNE-ANCA seems to promote or define the disease phenotype. CIMDL do not respond well to immunosuppressive therapy. Only the consistent removal of persistent stimuli of autoantibody production (cocaine, bacterial superinfections) can halt the disease process, prevent the progression of the lesions and promise success of surgical repair procedures.
Abstract: An Italian multicentre study was promoted in order to assess the accuracy of four anti-double-stranded DNA (dsDNA) antibody assays for SLE diagnosis and monitoring.
Abstract: The objective of this review was to define a core set of recommendations for the treatment of HCV-associated mixed cryoglobulinemia syndrome (MCS) by combining current evidence from clinical trials and expert opinion.
Abstract: Objectives. To validate the clinical significance of anti-IFI16 autoantibodies in SSc and assess their associations with serological markers of SSc. Methods. A semi-quantitative ELISA was used to detect anti-IFI16 autoantibodies in the sera of 344 SSc patients from seven Italian hospitals and 144 healthy controls. SSc-associated autoantibodies [anti-RNA polymerase III (anti-RNAP III) antibodies, anti-centromere, anti-topo I] and IF patterns were evaluated using commercial assays. Statistical analyses were performed to test clinical and serological associations. Results. The results of this study confirm a significant prevalence (29%) of anti-IFI16 antibodies in the SSc population (n = 344). Anti-IFI16 antibodies were also detected in 30% of the SSc patients who tested negative for both ACAs and anti-topo I (anti-Scl70) antibodies. In this subgroup of patients, anti-IFI16 antibodies were significantly associated with the limited cutaneous form of SSc with a sensitivity of 40% and a specificity of 81%. Moreover, analysis of the distribution of anti-RNAP III antibodies vs anti-IFI16 in the same SSc population showed that they were mutually exclusive. IIF revealed no association between anti-IFI16 and fluoroscopic patterns, due to a lack of IFI16 autoantigen in HEp-2 cells. Anti-IFI16 antibody levels were also significantly associated with heart involvement. Conclusions. Anti-IFI16 autoantibodies are frequently detected in SSc, displaying clinical and laboratory associations, and being particularly useful for diagnosis and disease classification in patients who are negative for other SSc serological markers.
Abstract: BACKGROUND AND OBJECTIVES: The objective of this study was to evaluate the prevalence, clinicopathologic features, and outcome of renal involvement in a large cohort of patients with primary antiphospholipid syndrome (PAPS). DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We retrospectively examined medical records of 160 patients with a diagnosis of PAPS of two general hospitals of northern Italy between 1985 and 2008. RESULTS: There were 140 women and 20 men. Mean age was 35+/-12 yr. PAPS was characterized by thrombotic events in 41.2%, fetal loss in 39.4%, and both in 19.4%. Signs of renal abnormalities were present in 14 (8.7%) patients. All patients had proteinuria, in the nephrotic range in five; four patients had moderate chronic renal insufficiency, and one had end-stage kidney disease (ESKD). Two patients presented with acute renal failure and one with nephritic syndrome. Ten patients underwent a renal biopsy, which showed a membranous glomerulonephritis in four, proliferative glomerulonephritis in two, thrombotic microangiopathy in two, and vascular lesions consistent with chronic antiphospholipid antibodies nephropathy in two. Patients with renal involvement were older (41.8 versus 34.3 years; P=0.0269), more frequently lupus anticoagulant positive (92.3 versus 48.9%; P=0.0068), and had hypocomplementemia (P<0.05). CONCLUSIONS: Renal abnormalities are present in approximately 9% of patients with PAPS. In addition to APS nephropathy, the prevailing picture is membranous nephropathy. Outcome and long-term follow-up usually are good. Not all of the clinical manifestations of PAPS can be ascribed to thrombotic mechanisms. The heterogeneity of renal involvement confirms the presence of a continuum between systemic lupus erythematosus and PAPS.
Abstract: Although less than 1% of patients with the antiphospholipid syndrome (APS) develop the catastrophic variant, its potentially lethal outcome emphasizes its importance in clinical medicine today. However, the rarity of this variant makes it extraordinarily difficult to study in any systematic way. In order to put together all of the published case reports as well as the new diagnosed cases from all over the world, an international registry of patients with catastrophic APS (CAPS Registry) was created in 2000 by the European Forum on Antiphospholipid Antibodies (see http://www.med.ub.es/MIMMUN/FORUM/CAPS.HTM). Currently, it documents the entire clinical, laboratory and therapeutic data of more than 300 patients whose data has been fully registered.
Abstract: OBJECTIVE: To update the follow-up of the Euro-Lupus Nephritis Trial (ELNT), a randomised prospective trial comparing low-dose (LD) and high-dose (HD) intravenous (IV) cyclophosphamide (CY) followed by azathioprine (AZA) as treatment for proliferative lupus nephritis. PATIENTS AND METHODS: Data for survival and kidney function were prospectively collected during a 10-year period for the 90 patients randomised in the ELNT, except in 6 lost to follow-up. RESULTS: Death, sustained doubling of serum creatinine and end-stage renal disease rates did not differ between the LD and HD group (5/44 (11%) vs 2/46 (4%), 6/44 (14%) vs 5/46 (11%) and 2/44 (5%) vs 4/46 (9%), respectively) nor did mean serum creatinine, 24 h proteinuria and damage score at last follow-up. Most patients in both groups were still treated with glucocorticoids, other immunosuppressant agents and blood pressure lowering drugs. After 10 years of follow-up, the positive predictive value for a good outcome of an early drop in proteinuria in response to initial immunosuppressive therapy was confirmed. CONCLUSION: The data confirm that a LD IVCY regimen followed by AZA-the "Euro-Lupus regimen"-achieves good clinical results in the very long term.
Abstract: Churg-Strauss angiitis or syndrome (CSA) is defined as an eosinophil-rich and granulomatous inflammation involving the respiratory tract, and necrotising vasculitis affecting small- to medium-sized vessels, and is associated with asthma and eosinophilia. It is usually classified among the so-called anti-neutrophil antibody (ANCA)-associated systemic vasculitides (AASVs) because of its clinical and pathological features that overlap with those of the other AASVs. However, two recent studies on large cohorts of patients have found that ANCAs, usually P-ANCAs/MPO-ANCAs, were present in only 38% of patients. Moreover, the ANCA status was shown to segregate with clinical phenotype. ANCA-positive patients were significantly more likely to have disease manifestations associated with small-vessel vasculitis, including necrotising glomerulonephritis, mononeuritis and purpura, whereas ANCA-negative cases were significantly more likely to have cardiac and lung involvement. Vasculitis was documented less frequently in histological specimens from ANCA-negative patients in comparison with ANCA-positive ones. These findings have led to postulate the predominance of distinct pathogenetic mechanisms in the two subsets of patients: an ANCA-mediated process in ANCA-positive patients and tissue infiltration by eosinophils with subsequent release of toxic product in ANCA-negative cases. Preliminary results suggest that ANCA-positive and ANCA-negative patients also might have a different genetic background. Corticosteroids remain the cornerstone of the initial treatment of CSA. The addition of cyclophosphamide is indicated in treatment of patients with poor-prognosis factors or in patients without poor-prognosis factors but those that are prone to relapses. The length of the maintenance therapy remains to be established. However, the vast majority of patients require long-term corticosteroids treatment to control asthma.
Abstract: In this study we assess the presence of antibodies against infectious agents as well as for a variety of autoantibodies in an attempt to establish associations between various vasculitides and infections in order to shed light on the etiopathogenesis of these diseases and perhaps implicate a potential cure. Sera from patients with Wegener's granulomatosis (WG), polyarteritis nodosa, microscopic polyangiitis, Churg Strauss, and giant cell arteritis were compared to healthy control sera. Serum samples were assessed, using the Bio-Rad BioPlex 2200, for the presence of Toxoplama gondii, cytomegalovirus (CMV), Epstein-Barr virus (EBV), Treponema pallidum, and Saccharomyces cerevisiae. Hepatitis B virus (HBV), hepatitis C virus (HCV), and anti-Helicobacter pylori antibodies were assessed by ELISA. In addition, sera were tested for a panel of antibodies associated with thrombophilia as well as various autoantibodies. The prevalence of antibodies toward HCV and H. pylori was significantly higher among patients with WG. IgG antibodies toward T. gondii and IgM antibodies toward CMV were significantly more common among WG patients than among controls. WG patients exhibited more antibodies toward EBV viral capsid antigen IgG and EBV early antigen IgG compared to sera from healthy controls. In WG, positive associations were disclosed between CMV IgG antibodies and the presence of gastrointestinal manifestations and renal involvement, and there was a higher Birmingham vasculitis activity score in association with elevated titers of EBV viral capsid antigen IgG antibodies. Otorhinolaryngeal manifestations were more common in those with positive IgG antibodies for EBV early antigen. Our results unveil novel associations between WG and various infectious agents, including HCV, H. pylori, T. gondii, CMV, and EBV. In addition to putative roles in initiation and exacerbation of the vasculitic process, it seems that these infectious agents also modulate the clinical phenotype of the disease.
Abstract: BACKGROUND: Urticarial vasculitis (UV) is an uncommon type of chronic urticaria (CU), which exhibits leucocytoclastic vasculitis. Painful and long-lasting (> 24 h) weals associated with purpura or bruising are considered indicative of UV. It is often responsive to oral corticosteroids and poorly to oral antihistamines. Hypocomplementaemia and systemic involvement are also commonly reported. AIMS: To diagnose patients with UV histologically and then compare their clinical features and response to various treatment regimens. METHODS: Biopsies were taken from 312 subjects with CU unresponsive to oral antihistamines; of these, 47 were histologically diagnosed as having UV. Biopsies were taken irrespective of the clinical features of weal eruption. Other diseases known to be associated with small-vessel vasculitis had previously been excluded. Results. Individual weals lasted < 24 h in 57.4% of patients, and pain or tenderness was reported only by 8.6%. Extracutaneous features were present in 81%, hypocomplementaemia in 11% and abnormalities of other laboratory parameters (i.e. raised erythrocyte sedimentation rate, microscopic haematuria) in 76.6%. Hydroxyzine was effective in only one patient. Both oral corticosteroids and cinnarizine were effective in a high percentage of the patients. CONCLUSION: This diagnostic approach allowed us to identify a large group (47 patients) with UV. Most did not present the clinical (prolonged duration of weals and bruising) and laboratory features that have previously been described as characteristic of UV. Cinnarizine was found to be a valuable treatment option.
Abstract: Anti-C1q antibodies are found in a variety of diseases, in addition to systemic lupus erythematosus (SLE), and in 3-5% of normal individuals. In particular, anti-C1q antibodies are detected at a high titer in 100% of patients with hypocomplementemic urticarial vasculitis and in 30-48% of SLE patients. Their titer correlates with active renal disease with a sensitivity of 44-100% and a specificity of 70-92%. An increase in anti-C1q antibody titer has been suggested to be able to predict renal flares in lupus nephritis so that monitoring anti-C1q might be valuable for the clinical management of SLE patients as a noninvasive biological marker. Recently our group studied 228 patients affected by lupus nephritis and found that the association of anti-C1q, C3, and C4, in a multivariate analysis, provided the best prediction of renal flares, particularly in patients with focal and diffuse proliferative lupus nephritis and in the absence of antiphospholipid antibodies.
Abstract: The complement (C') cascade is an important part of the innate immunity. It acts through three major pathways: classical (CP), alternative (AP) and mannose-binding-lectin (MP). C' reduction is a key feature in systemic lupus erythematosus (SLE), for its pathogenesis and for disease relapse. The aims of our study are to correlate C' variations with disease activity and verify the presence of C' deficiencies. We tested for three C' pathways 52 sera from 20 patients affected by SLE. A significant correlation between the ECLAM score and the degree of activation of the CP (Mann-Whitney; P = 0.001) was recorded, while the correlation with anti-dsDNA antibodies did not reach statistical significance (Mann-Whitney; P > 0.05). In conclusion, the ELISA assay can be considered well suited for testing SLE samples. We detected a significant link between the phases of lupus activity and the reduction of the CP.
Abstract: OBJECTIVE: To describe the clinical and laboratory features, as well as the precipitating factors, treatment and outcome of patients with catastrophic antiphospholipid syndrome (APS). METHODS: We analyzed the 280 patients included until September 2008 in the website based international registry of patients with catastrophic APS ("CAPS Registry") (http://www.med.ub.es/MIMMUN/FORUM/CAPS.HTM). RESULTS: The entire series includes 201 (72%) female and 79 (28%) male patients with a mean age of 37 +/- 14 years (range, 11-60 years). A total of 129 (46%) patients suffered from primary APS, 112 (40%) from systemic lupus erythematosus, 14 (5%) from lupus-like disease, and 25 (9%) from other autoimmune diseases. The catastrophic episode was the first manifestation of the APS in 129 (46%) patients. A precipitating factor was reported in 53% of the patients. The first clinical manifestation at the time of the catastrophic episode was a pulmonary complication in 24% of the cases, a neurologic feature in 18% and a renal feature in 18%. During the catastrophic episode, intraabdominal involvement was identified in the majority of patients, mainly consisting of renal (71%), hepatic (33%), gastrointestinal (25%), splenic (19%), adrenal (13%), and pancreatic (8%) manifestations. 123 (44%) patients died at the time of the catastrophic APS event but the higher recovery rate was achieved by the combination of anticoagulants plus corticosteroids plus plasma exchange (PE) and/or intravenous immunoglobulins (IVIG) (69% versus 54%). CONCLUSIONS: The catastrophic APS is an uncommon but potentially life-threatening condition that needs high clinical awareness. The therapeutical connotation is that this may be corrected with the combination of anticoagulation plus steroids plus attempts at achieving a prompt reduction of antiphospholipid antibody titer (i.e. PE and/or IVIG).
Abstract: OBJECTIVES: To evaluate the role of immunological tests for monitoring lupus nephritis (LN) activity. METHODS: C3, C4, anti-dsDNA and anti-C1q antibodies were prospectively performed over 6 years in 228 patients with LN. RESULTS: In membranous LN only anti-C1q antibodies differentiated proteinuric flares from quiescent disease (p = 0.02). However, in this group 46% of flares occurred with a normal value of anti-C1q antibodies versus 20% in proliferative LN (p = 0.02). In patients with antiphospholipid antibodies (APL), 33% of flares occurred with normal levels of anti-C1q antibodies versus 14.5% in patients that were APL-negative (p = 0.02). In proliferative LN, anti-C1q antibodies showed a slightly better sensitivity and specificity (80.5 and 71% respectively) than other tests for the diagnosis of renal flares. All four tests had good negative predictive value (NPV). At univariate analysis anti-C1q was the best renal flare predictor (p<0.0005). At multivariate analysis, the association of anti-C1q with C3 and C4 provided the best performance (p<0.0005, p<0.005, p<0.005 respectively). CONCLUSIONS: Anti-C1q is slightly better than the other tests to confirm the clinical activity of LN, particularly in patients with proliferative LN and in the absence of APL. All four "specific" tests had a good NPV, suggesting that, in the presence of normal values of each, active LN is unlikely.
Abstract: Systemic lupus erythematosus (SLE) is a complex, multisystem autoimmune disorder, which often involves referral to multiple medical specialists. Lupus nephritis (LN) occurs in ~35% of adults with SLE and predicts poor survival. There is currently no consensus on how to manage patients with SLE or LN across specialties and across different European countries. The Lupus Nephritis Terminology Advisory Group was formed to address this issue as it impacts upon LN treatment. It has developed consensus statements based on opinions from expert panel meetings with nephrologists, nephropathologists, rheumatologists, clinical immunologists and internal medicine specialists from many European countries, after reviewing current guidelines from the European League Against Rheumatism, the American College of Rheumatology and the participants' experience. In this article, we report consensus statements that were developed in six important areas: classification of patients with LN, how classification affects the selection of treatment options and definitions of induction, response, flare and maintenance. We have also proposed a consensus for the terminology involved in the management of LN that is consistent with clinical opinion gathered from multidisciplinary expert meetings and with existing guidelines. We believe this consensus approach provides agreed expert opinion to clinicians and will form the basis for optimising LN treatment.
Abstract: BACKGROUND: Current therapies for antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis are limited by toxicity. OBJECTIVE: To compare pulse cyclophosphamide with daily oral cyclophosphamide for induction of remission. DESIGN: Randomized, controlled trial. Random assignments were computer-generated; allocation was concealed by faxing centralized treatment assignment to providers at the time of enrollment. Patients, investigators, and assessors of outcomes were not blinded to assignment. SETTING: 42 centers in 12 European countries. PATIENTS: 149 patients who had newly diagnosed generalized ANCA-associated vasculitis with renal involvement but not immediately life-threatening disease. INTERVENTION: Pulse cyclophosphamide, 15 mg/kg every 2 to 3 weeks (76 patients), or daily oral cyclophosphamide, 2 mg/kg per day (73 patients), plus prednisolone. MEASUREMENT: Time to remission (primary outcome); change in renal function, adverse events, and cumulative dose of cyclophosphamide (secondary outcomes). RESULTS: Groups did not differ in time to remission (hazard ratio, 1.098 [95% CI, 0.78 to 1.55]; P = 0.59) or proportion of patients who achieved remission at 9 months (88.1% vs. 87.7%). Thirteen patients in the pulse group and 6 in the daily oral group achieved remission by 9 months and subsequently had relapse. Absolute cumulative cyclophosphamide dose in the daily oral group was greater than that in the pulse group (15.9 g [interquartile range, 11 to 22.5 g] vs. 8.2 g [interquartile range, 5.95 to 10.55 g]; P < 0.001). The pulse group had a lower rate of leukopenia (hazard ratio, 0.41 [CI, 0.23 to 0.71]). LIMITATIONS: The study was not powered to detect a difference in relapse rates between the 2 groups. Duration of follow-up was limited. CONCLUSION: The pulse cyclophosphamide regimen induced remission of ANCA-associated vasculitis as well as the daily oral regimen at a reduced cumulative cyclophosphamide dose and caused fewer cases of leukopenia. PRIMARY FUNDING SOURCE: The European Union.
Abstract: BACKGROUND: Antinucleosome antibodies (anti-NCS) are reported to be highly sensitive and specific for systemic lupus erythematosus (SLE) and to correlate with disease activity. They may appear in early stages of the disease, in particular before anti-dsDNA antibodies, being a potential marker for identifying patients susceptible to SLE. Patients with primary antiphospholipid syndrome (PAPS) may develop full-blown SLE but there is no evidence for markers predictive for that. AIM: To evaluate whether anti-NCS may be predictors for full-blown or lupus like disease (LL) in a cohort of PAPS patients. METHODS: A multicentric cohort of 105 PAPS patients was tested for IgG/IgM anti-NCS by using a home made assay with H1-stripped chromatin as antigen. RESULTS: Eighty-one out of 105 (77%) of the patients were positive for anti-NCS; medium-high titre results were present only in 49/105 (46%). Anti-NCS were more frequently detected in PAPS+LL, but no relationship with clinical/serological features was found, except for a weak correlation with anti-dsDNA antibodies. Two PAPS patients evolved into full-blown SLE during the follow-up and displayed high titre anti-NCS many years before. CONCLUSIONS: Our findings suggest that anti-NCS might be added to the mosaic of autoimmune phenomena characterizing PAPS patients and in particular those with more chance to evolve to SLE.
Abstract: OBJECTIVE: It was reported by several groups that patients diagnosed as primary antiphospholipid syndrome (PAPS) had developed a full-blown systemic lupus erythematosus (SLE) even after many years of follow-up. Little is known about clinical and/or serological factors that may help predict such evolution. Antinucleosome antibodies (anti-NCS) were described to appear in early stages of SLE, in particular before anti-dsDNA antibodies. The aim of the study is to evaluate the prevalence of anti-NCS in a large cohort of PAPS patients. METHODS: IgG and IgM anti-NCS antibodies were detected using a home made assay with H1-stripped chromatin as antigen. Sera from 106 PAPS patients were tested; 52 of them were also tested during the follow-up, at least 2 years apart form the basal sample. RESULTS: Medium-high titre anti-NCS were found in nearly half of the patients (49/106, 46%), more frequently in those presenting features of "lupus like disease". Most of patients displayed an unchanged pattern of anti-NCS over time. We describe three cases of PAPS patients that developed SLE after many years of follow-up; high titre and low titre anti-NCS were present in two and one of them respectively several years before evolving into SLE. CONCLUSIONS: A significant proportion of PAPS patients displayed medium-high titre anti-NCS, suggesting that the autoimmune response against chromatin may be a relevant event not only in patients with SLE. Further studies are warranted to explore the predictive value of anti-NCS with respect to the evolution from PAPS to SLE.
Abstract: BACKGROUND: The asthmatic-prodromal phase of Churg-Strauss syndrome (CSS) is usually considered allergic, but data about the involved allergens are scarce. The aim of our work was to examine the prevalence of allergy in a group of CSS patients and in two control groups of persistent asthmatic subjects selected for eosinophilia >10% [first control group patients (CGP1)] and eosinophils <6% [second control group patients (CGP2)]. METHODS: The respiratory symptoms, and the results of prick test and/or RAST for the common allergens, performed before the vasculitic phase in 51 CSS, were retrospectively evaluated and compared with those of 46 CGP1 and 50 CGP2. RESULTS: 31.4% of CSS vs 67.4% of CGP1 (P = 0.0004) and vs 58.0% CGP2 (P = 0.007) were allergic. The number of subjects with seasonal allergies was lower in CSS vs CGP1 (P = 0.0069) and vs CGP2 (P = 0.0002). The number of perennial allergies was significantly higher in CSS than in both control groups (CSS vs CGP1, P = 0.0108; CSS vs CGP2, P = 0.0079). The subjects allergic to Dermatophagoides were prevalent in CSS vs CGP1 (P = 0.0045) but not vs CGP2. CONCLUSIONS: The evidence of allergy, considered as the demonstration of specific IgE consistent with the clinical history, is present in less than one-third of CSS and the higher prevalence of seasonal allergies in the controls disagrees with persistent asthma. Allergy may be only one of several mechanisms triggering exacerbation of asthma or supporting chronic airway inflammation as in asthma in general. Alternatively, unidentified allergens may play a role.
Abstract: Systemic vasculitis associated with autoantibodies to neutrophil cytoplasmic antigens (ANCA) is the most frequent cause of rapidly progressive glomerulonephritis. Renal failure at presentation carries an increased risk for ESRD and death despite immunosuppressive therapy. This study investigated whether the addition of plasma exchange was more effective than intravenous methylprednisolone in the achievement of renal recovery in those who presented with a serum creatinine >500 micromol/L (5.8 mg/dl). A total of 137 patients with a new diagnosis of ANCA-associated systemic vasculitis confirmed by renal biopsy and serum creatinine >500 micromol/L (5.8 mg/dl) were randomly assigned to receive seven plasma exchanges (n = 70) or 3000 mg of intravenous methylprednisolone (n = 67). Both groups received oral cyclophosphamide and oral prednisolone. The primary end point was dialysis independence at 3 mo. Secondary end points included renal and patient survival at 1 yr and severe adverse event rates. At 3 mo, 33 (49%) of 67 after intravenous methylprednisolone compared with 48 (69%) or 70 after plasma exchange were alive and independent of dialysis (95% confidence interval for the difference 18 to 35%; P = 0.02). As compared with intravenous methylprednisolone, plasma exchange was associated with a reduction in risk for progression to ESRD of 24% (95% confidence interval 6.1 to 41%), from 43 to 19%, at 12 mo. Patient survival and severe adverse event rates at 1 yr were 51 (76%) of 67 and 32 of 67 (48%) in the intravenous methylprednisolone group and 51 (73%) of 70 and 35 of (50%) 70 in the plasma exchange group, respectively. Plasma exchange increased the rate of renal recovery in ANCA-associated systemic vasculitis that presented with renal failure when compared with intravenous methylprednisolone. Patient survival and severe adverse event rates were similar in both groups.
Abstract: Catastrophic antiphospholipid syndrome (CAPS), described by Asherson in 1992, is a rare form of antiphospholipid syndrome resulting in multiorgan failure with a mortality rate of about 50%. The syndrome occurs in patients with either systemic lupus erythematosus and other rheumatic diseases (systemic sclerosis, rheumatoid arthritis, primary Sjogren syndrome) or alone. Whereas in "classic" antiphospholipid syndrome (APS), medium-large vessels are involved, a diffuse small vessel ischemia and thrombosis (microangiopathic disease) leading to a severe multiorgan dysfunction is predominant in CAPS. "Trigger" factors have been demonstrated in 45% of patients, but in the majority, they remain unknown. Not infrequently, CAPS arises in patients without any previous thrombotic history. The kidney is the organ most commonly affected, followed by the lung, the central nervous system, the heart and the skin. Disseminated intravascular coagulation occurs in approximately 13% of patients. The present study reports the clinical and serological features of 4 patients affected by this rare form of antiphospholipid syndrome. Nephrologists should be aware of the possibility of this syndrome as a cause of multiorgan failure since prompt recognition is essential for effective treatment.
Abstract: OBJECTIVE: To explore the association between HLA alleles and Churg-Strauss syndrome (CSS), and to investigate the potential influence of HLA alleles on the clinical spectrum of the disease. METHODS: Low-resolution genotyping of HLA-A, HLA-B, and HLA-DR loci and genotyping of TNFA -238A/G and TNFA -308A/G single-nucleotide polymorphisms were performed in 48 consecutive CSS patients and 350 healthy controls. RESULTS: The frequency of the HLA-DRB1*07 allele was higher in the CSS patients than in controls (27.1% versus 13.3%; chi(2) = 12.64, P = 0.0003, corrected P [P(corr)] = 0.0042, odds ratio [OR] 2.42, 95% confidence interval [95% CI] 1.47-3.99). The HLA-DRB4 gene, present in subjects carrying either HLA-DRB1*04, HLA-DRB1*07, or HLA-DRB1*09 alleles, was also far more frequent in patients than in controls (38.5% versus 20.1%; chi(2) = 16.46, P = 0.000058, P(corr) = 0.000232, OR 2.49, 95% CI 1.58-3.09). Conversely, the frequency of the HLA-DRB3 gene was lower in patients than in controls (35.4% versus 50.4%; chi(2) = 7.62, P = 0.0057, P(corr) = 0.0228, OR 0.54, 95% CI 0.35-0.84). CSS has 2 major clinical subsets, antineutrophil cytoplasmic antibody (ANCA)-positive, with features of small-vessel vasculitis, and ANCA-negative, in which organ damage is mainly mediated by tissue eosinophilic infiltration; analysis of HLA-DRB4 in patients categorized by different numbers of vasculitic manifestations (purpura, alveolar hemorrhage, mononeuritis multiplex, rapidly progressive glomerulonephritis, and constitutional symptoms) showed that its frequency strongly correlated with the number of vasculitis symptoms (P for trend = 0.001). CONCLUSION: These findings indicate that HLA-DRB4 is a genetic risk factor for the development of CSS and increases the likelihood of development of vasculitic manifestations of the disease.
Abstract: OBJECTIVE: Prothrombin (PT) is a target for antibodies with lupus anticoagulant (LA) activity, suggesting the possible application of anti-prothrombin antibody (aPT) assays in patients with antiphospholipid syndrome (APS). Different methods - both homemade and commercial - for the detection of aPT are available, but they seem to produce conflicting results. The purpose of this study was to compare the performance of different assays on a set of well-characterized serum samples. PATIENTS AND METHODS: Sera were gathered from 4 FIRMA institutions, and distributed to 15 participating centres. Forty-five samples were from patients positive for LA and/or anticardiolipin antibodies (aCL) with or without APS, and 15 were from rheumatoid arthritis (RA) patients negative for antiphospholipid antibodies. The samples were evaluated for IgG and IgM antibodies using a homemade direct aPT assay (method 1), a homemade phosphatidylserine-dependent aPT assay (aPS/PT, method 2), and two different commercial kits (methods 3 and 4). In addition, a commercial kit for the detection of IgG-A-M aPT (method 5) was used. RESULTS: Inter-laboratory results for the 5 methods were not always comparable when different methods were used. Good inter-assay concordance was found for IgG antibodies evaluated using methods 1, 3, and 4 (Cohen k > 0.4), while the IgM results were discordant between assays. In patients with thrombosis and pregnancy losses, method 5 performed better than the others. CONCLUSION: While aPT and aPS/PT assays could be of interest from a clinical perspective, their routine performance cannot yet be recommended because of problems connected with the reproducibility and interpretation of the results.
Abstract: The detection and measurement of antibodies to double-stranded (ds) DNA is important in the diagnosis and monitoring of patients with systemic lupus erythematosus (SLE). Several methods are available for their determination but none of them is completely satisfactory. Usually, purified dsDNA from different sources is used as antigen in the solid (enzyme-linked immunosorbent assay, ELISA) or liquid phase (Farr assay). Alternatively, anti-dsDNA antibodies can be demonstrated by immunofluorescence, using the haemoflagellate Crithidia luciliae (CLIFT). We have developed a new oligonucleotide-based anti-dsDNA ELISA in which dsDNA, constituted of a 5'photobiotinylated nucleic acid probe and its highly specific complementary oligonucleotide, is formed onto the solid-phase. To do that, a 40 bp probe is coated on the microplate wells via streptavidin-biotin bond and the in vitro (in solid-phase) developed hybrid between probe and its complementary helix used as capturing antigen. The assay has proved to be specific and the several experiments performed to ascertain the absence of single-stranded DNA (ssDNA) contamination and/or non specific binding to plastic, streptavidin, probe (without complementary chain) have all excluded any significant interference. To evaluate the clinical performance of this new assay, 114 serum samples from 68 SLE patients and 85 samples from 85 disease controls, in addition to 30 blood donors, were studied. The results were compared with commercial ELISAs, Farr assay and indirect immunofluorescence. The sensitivity and specificity were 66.2 and 96.4%, respectively, comparable and even better than those of the commercially available anti-dsDNA kits. Anti-dsDNA antibody levels, measured with the oligonucleotide-ELISA, correlated with SLE clinical activity determined using the European Consensus Lupus Activity Measurement (ECLAM) (r = 0.59, p < 0.0001). In conclusion, this assay has proved to be reproducible, and the results correlate well with other standard anti-dsDNA assays. The features of this new assay make it promising for clinical use.
Abstract: The prognosis of untreated ANCA-associated systemic vasculitis (AASV) is poor with up to 90% of patients dying within 2 years. The combination of prednisone and cyclophosphamide is now established as the treatment of choice and leads to control of the disease in 80-90% of the patients. Such treatment has turned these acutely fatal diseases into chronic relapsing disorders with accumulating drug-related morbidity in over 50% of the patients, including diabetes, bladder and lympho-proliferative malignancy and infertility. Treatment of AASV can be divided into three phases: therapy for induction of remission, for maintenance of remission and therapy for refractory and relapsing disease. In addition, the treatment must be tailored to the stage and severity of the disease and a new classification of AASV was introduced: localized vasculitis, early systemic vasculitis, generalized vasculitis, severe renal vasculitis and refractory vasculitis. Different randomized clinical trials have been performed with the aim of optimizing the existing therapeutic regimens: some of these have been concluded, others are still ongoing. Newer therapeutic approaches are currently being tested and have involved the use of mycophenolate mofetil, anti tumour necrosis factor (TNF) drugs (anti TNF antibody infliximab and humanized soluble TNF receptor etanercept), monoclonal anti- lymphocyte antibody (anti-CD20). These new alternative therapies could be used in patients with frequent relapses, in patients who fail to achieve remission with standard induction therapy and in those with severe side effects due to cumulative doses of cyclophosphamide.
Abstract: BACKGROUND: Churg-Strauss syndrome (CSS) is a rare disorder characterized by asthma, eosinophilia, and systemic vasculitis. Renal involvement is not regarded as a prominent feature, and its prevalence and severity vary widely in published reports that usually refer to small series of selected patients. METHODS: We examined the prevalence, clinicopathologic features, and prognosis of renal disease in 116 patients with CSS. RESULTS: There were 48 men and 68 women with a mean age of 51.9 years (range, 18 to 86 years). Signs of renal abnormalities were present in 31 patients (26.7%). Rapidly progressive renal insufficiency was documented in 16 patients (13.8%); urinary abnormalities, 14 patients (12.1%); and chronic renal impairment, 1 patient. There were 3 additional cases of obstructive uropathy. Sixteen patients underwent renal biopsy, which showed necrotizing crescentic glomerulonephritis in 11 patients. Other diagnoses were eosinophilic interstitial nephritis, mesangial glomerulonephritis, and focal sclerosis. Antineutrophil cytoplasmic antibody (ANCA) was positive in 21 of 28 patients (75.0%) with nephropathy versus 19 of 74 patients without (25.7%; P < 0.001). In particular, all patients with necrotizing crescentic glomerulonephritis were ANCA positive. After a median follow-up of 4.5 years, 10 patients died (5 patients with nephropathy) and 7 patients developed mild chronic renal insufficiency. Five-year mortality rates were 11.7% (95% confidence interval, 3.9 to 33.3) in patients with nephropathy and 2.7% (95% confidence interval, 0.7 to 10.7) in those without (P = 0.10). CONCLUSION: Renal abnormalities are present in about one quarter of patients with CSS. The prevailing picture is ANCA-associated necrotizing crescentic glomerulonephritis; however, other forms of nephropathy also may occur. Outcome and long-term follow-up usually are good.
Abstract: OBJECTIVE: To assess the prevalence of anti-Ro/SSA in RA and to analyse clinical and serological features of anti-Ro/SSA positive patients with RA. METHODS: 195 consecutive patients affected by RA were studied by counterimmunoelectrophoresis and ELISA for the detection of anti-Ro/SSA antibodies. Anti-Ro were found in 12 patients, with a prevalence of 6%. These 12 patients were pooled with other 15 patients known to have anti-Ro/SSA antibodies and RA, in order to evaluate their clinical and laboratory features. RESULTS: Anti-Ro positive patients showed a common pattern of joint involvement at onset and a comparable progression of disease compared to anti-Ro negative subjects. In addition, extra-articular manifestations (such as xerophthalmia, xerostomia, scleritis, oral ulcers and amyloidosis) and peculiar autoantibody profile (hypergammaglobulinemia, anti-dsDNA and AMA) were found significantly associated to anti-Ro/SSA positivity. Even though DMARDs withdrawals were more frequently detected in anti-Ro/SSA patients, especially when using gold salts, no statistical difference between the two groups was detected. In addition, anti-TNFalpha treatment did not cause further progression of autoimmunity neither on laboratory nor on clinical ground. CONCLUSION: Anti-Ro/SSA can be detected in about 6% of patients affected by RA. These patients presented a peculiar clinical picture characterised by extra-articular manifestations some of which are known to be anti-Ro/SSA correlated, while others are more disease-specific (amyloidosis, episcleritis). Anti-Ro/SSA are significantly associated with other autoantibodies not specific for RA such as anti-dsDNA and AMA. Treatment with anti-TNF drugs did not cause further progression of autoimmunity neither on laboratory nor on clinical ground.
Abstract: The "Euro-Lupus Cohort" is composed by 1000 patients with systemic lupus erythematosus (SLE) that have been followed prospectively since 1991. These patients have been gathered by a European consortium--the "Euro-Lupus Project Group". This consortium was originated as part of the network promoted by the "European Working Party on SLE", a working group created in 1990 in order to promote research in Europe on the different problems related to this disease. The "Euro-Lupus Cohort" provides an updated information on the SLE morbidity and mortality characteristics in the present decade as well as defines several clinical and immunological prognostic factors.
Abstract: BACKGROUND: The role of anti-glomerular basement membrane (GBM) antibodies in the pathogenesis of Goodpasture syndrome (GPS) is firmly established. Untreated, the disease may follow a fulminating course. Early identification of patients has important implications in terms of management and prognosis. Therefore, a diagnostic test for the determination of circulating anti-GBM antibodies, of very high sensitivity and specificity, is necessary. A number of assays, using different antigenic substrates, are available, but studies comparing the 'performances' of the different tests are scarce. METHODS: The aim of our work was to evaluate the sensitivity and specificity of four immunoassay-based anti-GBM antibodies kits. Thirty-four serum samples from 19 GPS patients, 41 pathological and 28 normal controls were studied retrospectively (the follow-up samples were not included in the analysis of performance data). Cut-off limits were derived from receiver operating characteristics curve analysis. RESULTS: All the assays showed a comparable good sensitivity (between 94.7 and 100.0%), whereas specificity varied considerably (from 90.9 to 100.0%). The better performance in terms of sensitivity/specificity was achieved by a fluorescence immunoassay which utilizes a recombinant antigen. CONCLUSION: All the assays have a good performance, with high sensitivity; however, the specificity may vary considerably.
Abstract: The clinical impact of anti-DNA antibodies lies on their diagnostic power for systemic lupus erythematosus (SLE), being a formal classification criterion. In spite of such a disease association, low-avidity anti-DNA antibodies might also be part of the natural autoantibody repertoire. Their switch to pathogenic high-avidity autoantibodies is the result of the autoimmune process leading to SLE.Anti-DNA antibodies were shown to play a role in SLE pathogenesis and particularly in kidney damage. Accordingly, antibody titres might fluctuate in relation to disease activity, but their prognostic value for flares is still debated.Several methods for anti-DNA detection were described and there is evidence that the assays identify different antibodies with different prognostic value. The results of a multicenter study on four different routine tests for anti-dsDNA antibody detection showed that: (i) Farr assay displays the best diagnostic specificity/sensitivity for SLE, followed by Crithidia luciliae method (CLIFT), (ii) the new generation of solid phase assay (EliA) shows an increased sensibility versus the classical enzyme linked immune assay (ELISA) but a decreased specificity. Antibody titre detected by EliA and Farr assay correlated with disease activity. These findings would suggest that more than one assay should be useful for SLE diagnosis and monitoring.
Abstract: Recently, anti-C1q autoantibodies have been proposed as a useful marker in systemic lupus erythematosus (SLE) since their occurrence correlates with renal involvement and, possibly, with nephritic activity. We aimed to evaluate the prevalence of anti-C1q antibodies in patients with SLE, with and without renal involvement, and to correlate these markers' presence and levels with the activity of the disease and nephropathy. We studied 61 patients with SLE, 40 of whom had biopsy-proven lupus nephritis; 35 patients with other connective tissue diseases; and 54 healthy controls. In addition, 18 lupus nephritis patients were followed up during the disease time course. Anti-C1q antibodies were measured using "homemade" ELISA with high salt concentration (1 M sodium chloride). High anti-C1q antibody titers (> 55 AU) were present in 27 of 61 (44%) SLE patients and in 4% and 0% of normal blood donors and pathologic controls, respectively. Anti-C1q antibodies were found in 60% of patients with lupus nephritis compared with only 14% of SLE patients without nephropathy (P < 0.05). Moreover, patients who were positive for anti-C1q antibodies had a higher European Consensus Lupus Activity Measurement (ECLAM) score (4.35 vs. 2.2); 89% of patients with active lupus nephritis showed high titers of anti-C1q antibodies compared with 0% of patients with inactive nephritis. Anti-C1q and anti-dsDNA antibodies agreed in 79% of cases. Our results confirm that anti-C1q antibodies are present in a significant percentage of SLE patients, and that their presence and levels correlate with disease activity-in particular, during renal flare-ups.
Abstract: OBJECTIVE: Churg-Strauss syndrome (CSS) is classified among the so-called antineutrophil cytoplasmic antibody-associated systemic vasculitides (AASVs) because of its clinicopathologic features that overlap with the other AASVs. However, while antineutrophil cytoplasmic antibodies (ANCAs) are consistently found in 75-95% of patients with Wegener's granulomatosis or microscopic polyangiitis, their prevalence in CSS varies widely and their clinical significance remains uncertain. We undertook this study to examine the prevalence and antigen specificity of ANCAs in a large cohort of patients with CSS. Moreover, we evaluated the relationship between ANCA positivity and clinicopathologic features. METHODS: Immunofluorescence and enzyme-linked immunosorbent assay were used to determine the presence or absence of ANCAs in 93 consecutive patients at the time of diagnosis. The main clinical and pathologic data, obtained by retrospective analysis, were correlated with ANCA status. RESULTS: ANCAs were present by immunofluorescence in 35 of 93 patients (37.6%). A perinuclear ANCA (pANCA) pattern was found in 26 of 35 patients (74.3%), with specificity for myeloperoxidase (MPO) in 24 patients, while a cytoplasmic ANCA pattern, with specificity for proteinase 3, was found in 3 of 35 patients (8.6%). Atypical patterns were found in 6 of 30 patients with anti-MPO antibodies (20.0%). ANCA positivity was associated with higher prevalences of renal disease (51.4% versus 12.1%; P < 0.001) and pulmonary hemorrhage (20.0% versus 0.0%; P = 0.001) and, to a lesser extent, with other organ system manifestations (purpura and mononeuritis multiplex), but with lower frequencies of lung disease (34.3% versus 60.3%; P = 0.019) and heart disease (5.7% versus 22.4%; P = 0.042). CONCLUSION: ANCAs are present in approximately 40% of patients with CSS. A pANCA pattern with specificity for MPO is found in most ANCA-positive patients. ANCA positivity is mainly associated with glomerular and alveolar capillaritis.
Abstract: Connective tissue diseases represent a group of heterogeneous disorders that share certain common features, including inflammation of the skin, joints and other structures rich in connective tissue, as well as altered immunoregulation patterns, including autoantibody production and cell-mediated immunity abnormalities. While certain distinct clinical entities can be defined, manifestations can vary considerably from patient to patient, and the overlap of clinical features between and among specific diseases is common. Genetic, environmental and sex hormonal factors are likely to be of pathogenic importance. Among these diseases, systemic lupus erythematosus is the most frequent, followed by systemic sclerosis or scleroderma (SSc), Sjogren's disease, polymyositis and dermatomyositis and mixed connective tissue disease. Systemic sclerosis involves multiple organs in a process consisting of disseminated sclerosis affecting all compartments. Prominent vascular lesions typify the renal lesions. Scleroderma crisis is a major complication of SSc, characterized by severe hypertension, rapidly progressive renal failure, thrombotic microangiopathy with hemolitic anemia and low platelet count: the prompt use of angiotensin-converting enzyme (ACE) inhibitors significantly increased the 1-yr survival rate from 15 to 76%. Sjogren's syndrome is an immunologic disorder characterized by progressive lymphocytic destruction of the exocrine gland, frequently resulting in symptomatic eye and mouth dryness. The interstitial lesions constitute the principal renal manifestations: interstitial infiltrates and small lymphocytes, which can be homogenous and massive. In polymyositis and dermatomyositis renal involvement is rare.
Abstract: The value of anti-neutrophil cytoplasmic antibody (ANCA) detection for monitoring disease activity in ANCA-associated systemic vasculitis (AASV) remains controversial. The aim of our work was to rate the performance of a new automated fluorescence PR3 and MPO-ANCA immunoassay (EliA) for monitoring disease activity in AASV. We evaluated 100 serum samples from 71 AASV patients (with Wegener's granulomatosis, microscopic polyangiitis, and Churg-Strauss syndrome) as well as sera from 58 pathological and 35 normal controls. In addition to PR3 and MPO-ANCA EliA, we performed indirect immunofluorescence and "homemade" PR3 and MPO-ANCA ELISA tests. In AASV patients, ANCA levels were correlated with disease activity, according to the Birmingham Vasculitis Activity Score (BVAS). We derived cutoff limits from receiver operating characteristic (ROC) curve analysis comparing AASV with pathological controls. Our results showed that EliA and ELISA had comparable sensitivity (76%) and specificity (95%). The analysis of active versus inactive status and correlation with ANCA levels showed a clear difference between BVAS Group I (score < or = 4) and BVAS Group II (scores > 4) (AUC = 0.86 vs. 0.72; relative risk [RR] = 2.4; P < 0.0001) for PR3-ANCA, but not for MPO-ANCA (AUC = 0.94 vs. 0.87; RR = 1.48; P = 0.46). Serial serum samples from 16 patients were examined in detail. For the majority of patients, for both PR3 and MPO-ANCA, change in titer was strongly associated with change in BVAS score. Our data showed a good correlation between ANCA titer (especially for PR3) and AASV disease activity. We recommend that ANCA titer be used to monitor AASV disease activity with the caveat that a few exceptions, in particular with MPO-ANCA, are possible.
Abstract: The laboratory and particularly clinical immunology laboratories have an essential role in diagnosing and monitoring systemic lupus erythematosus (SLE), as well as other connective tissue diseases. The role of the clinical immunology laboratory in these diseases is to confirm or exclude diagnosis, to monitor disease activity, and to identify subgroup of patients. To obtain the best results in terms of diagnostic performance and clinical usefulness, the following recommendations should be fulfilled: anti-nuclear antibodies (ANA) determination by indirect immunofluorescence on Hep-2 cells is an effective screening assay in patients with clinical features of SLE. A negative ANA test makes the diagnosis of SLE unlikely. Anti-dsDNA antibodies are highly specific for SLE and are associated with renal involvement. The method of choice for anti-dsDNA is the Farr assay; however, the necessity of using radioactive materials reduces its applicability. As an alternative, immunofluorescence on Crithidia Luciliae can be used in the diagnostic phase due to its high specificity. The detection of antibodies to extractable nuclear antigens (ENA) and to phospholipids (lupus anticoagulant and anti-cardiolipin antibodies) is useful in identifying subgroups of patients at risk for some clinical manifestations. Anti-dsDNA measurement with a quantitative assay (the Farr assay or ELISA) is currently the best method to monitor disease activity along with complement levels. New assays (anti-C1q and anti-nucleosome antibodies) have been recently proposed for the diagnosis (anti-nucleosome) and monitoring of SLE patients (anti-C1q and anti-nucleosome antibodies), with promising results.
Abstract: Antineutrophil cytoplasmic antibodies (ANCA) are a sensitive and specific marker for ANCA-associated systemic vasculitis. Using indirect immunofluorescence on ethanol-fixed neutrophils, two major fluoroscopic patterns can be recognised: a diffuse cytoplasmic staining (C-ANCA), and a perinuclear/nuclear staining (P-ANCA). In patients with vasculitis, more of 90% of C-ANCA are directed against proteinase 3 (PR3-ANCA) whereas approximately 80-90% of P-ANCA recognise myelperoxidase (MPO-ANCA). Although C-ANCA (PR3-ANCA) is preferentially associated with Wegener's granulomatosis (WG), and P-ANCA (MPO-ANCA) with microscopic polyangiitis (MPA), idiopathic necrotising crescentic glomerulonephritis (iNCGN) and Churg-Strauss syndrome (CSS), there is not absolute specificity. Between 10-20% of patients with classical WG show P-ANCA (MPO-ANCA), and even a larger percentage of patients with MPA or CSS have C-ANCA (PR3-ANCA). Furthermore, it should be stressed that approximately 10-20% of patients with WG or MPA (and 40-50% of cases of CSS) have negative assay for ANCA. The best diagnostic performance is obtained when indirect immunofluorescence is combined with PR3 and MPO-specific ELISAs. ANCA with different and unknown antigen specificity are found in a variety of conditions other than AASV, including inflammatory bowel diseases, other autoimmune diseases, and infections where their clinical significance is unclear. ANCA levels are useful to monitor disease activity but should not be used by themselves to guide treatment. A significant increase in ANCA titres, or the reappearance of ANCA, should alert the clinicians and lead to a stricter patient control.
Abstract: OBJECTIVE: In the Euro-Lupus Nephritis Trial (ELNT), 90 patients with lupus nephritis were randomly assigned to a high-dose intravenous cyclophosphamide (IV CYC) regimen (6 monthly pulses and 2 quarterly pulses with escalating doses) or a low-dose IV CYC regimen (6 pulses of 500 mg given at intervals of 2 weeks), each of which was followed by azathioprine (AZA). After a median followup of 41 months, a difference in efficacy between the 2 regimens was not observed. The present analysis was undertaken to extend the followup and to identify prognostic factors. METHODS: Renal function was prospectively assessed quarterly in all 90 patients except 5 who were lost to followup. Survival curves were derived using the Kaplan-Meier method. RESULTS: After a median followup of 73 months, there was no significant difference in the cumulative probability of end-stage renal disease or doubling of the serum creatinine level in patients who received the low-dose IV CYC regimen versus those who received the high-dose regimen. At long-term followup, 18 patients (8 receiving low-dose and 10 receiving high-dose treatment) had developed permanent renal impairment and were classified as having poor long-term renal outcome. We demonstrated by multivariate analysis that early response to therapy at 6 months (defined as a decrease in serum creatinine level and proteinuria <1 g/24 hours) was the best predictor of good long-term renal outcome. CONCLUSION: Long-term followup of patients from the ELNT confirms that, in lupus nephritis, a remission-inducing regimen of low-dose IV CYC followed by AZA achieves clinical results comparable with those obtained with a high-dose regimen. Early response to therapy is predictive of good long-term renal outcome.
Abstract: Azathioprine (AZA) is a widely-used drug in the treatment of different diseases such as vasculitis, systemic lupus erythematosus, rheumatoid arthritis, inflammatory bowel diseases and in renal transplantation. Side effects of AZA can be classified as toxic, mainly dose related (myelosuppression and hepatotoxicity) and idiosyncratic, mainly dose independent. While the toxic effects are common and well documented, the hypersensitivity reactions are rare and it is not often easy to distinguish them from systemic sepsis or disease recurrence. We report two cases of AZA hypersensitivity occurring in patients with anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis each mimicking a vasculitis relapse or a septic complication of immunosuppression, as well as a review of the literature.
Abstract: BACKGROUND: The primary systemic vasculitides usually associated with autoantibodies to neutrophil cytoplasmic antigens include Wegener's granulomatosis and microscopic polyangiitis. We investigated whether exposure to cyclophosphamide in patients with generalized vasculitis could be reduced by substitution of azathioprine at remission. METHODS: We studied patients with a new diagnosis of generalized vasculitis and a serum creatinine concentration of 5.7 mg per deciliter (500 micromol per liter) or less. All patients received at least three months of therapy with oral cyclophosphamide and prednisolone. After remission, patients were randomly assigned to continued cyclophosphamide therapy (1.5 mg per kilogram of body weight per day) or a substitute regimen of azathioprine (2 mg per kilogram per day). Both groups continued to receive prednisolone and were followed for 18 months from study entry. Relapse was the primary end point. RESULTS: Of 155 patients studied, 144 (93 percent) entered remission and were randomly assigned to azathioprine (71 patients) or continued cyclophosphamide (73 patients). There were eight deaths (5 percent), seven of them during the first three months. Eleven relapses occurred in the azathioprine group (15.5 percent), and 10 occurred in the cyclophosphamide group (13.7 percent, P=0.65). Severe adverse events occurred in 15 patients during the induction phase (10 percent), in 8 patients in the azathioprine group during the remission phase (11 percent), and in 7 patients in the cyclophosphamide group during the remission phase (10 percent, P=0.94 for the comparison between groups during the remission phase). The relapse rate was lower among the patients with microscopic polyangiitis than among those with Wegener's granulomatosis (P=0.03). CONCLUSIONS: In patients with generalized vasculitis, the withdrawal of cyclophosphamide and the substitution of azathioprine after remission did not increase the rate of relapse. Thus, the duration of exposure to cyclophosphamide may be safely reduced.
Abstract: OBJECTIVES: To evaluate the prevalence and clinical significance of cathepsin G antibodies in patients affected with systemic sclerosis (SSc, scleroderma). METHODS: 115 patients affected by SSc, 55 (47,8%) with diffuse scleroderma (dSSc) and 60 (52,2%) with limited scleroderma (lSSc), were tested for cathepsin G antibodies by ELISA method. Moreover these sera were evaluated by indirect immunofluorescence (IIF) on ethanol and formalin fixed human neutrophils. RESULTS: By means of the ELISA method 16 (13,9%) patients were found to be sera positive for anti-cathepsin G, 2 (12.5%) of which showed a perinuclear fluorescence pattern (P-ANCA) and 4 (25%) an atypical ANCA staining, while 10 (62,5%) were negative on IIF. The IIF on scleroderma sera revealed 5 (4,3%) P-ANCA and 18 (15,7%) atypical ANCA patterns. The anti-cathepsin G antibodies significantly prevailed in scleroderma sera (p=0.02) when their frequency was compared with that of healthy controls; while they were not significantly associated to any clinical or serological features of SSc patients. CONCLUSIONS: The anti-cathepsin G antibodies were significantly frequent in scleroderma sera; however, no clinical correlations were found. Thus, the significance of their presence in SSc still needs to be clarified.
Abstract: ANCA-associated vasculitis.The term "antineutrophil cytoplasm antibody (ANCA)- associated vasculitis" (AASV) ihighers generally used to include primary vasculitis syndromes in which circulating ANCA against proteinase 3 (PR3) and myeloperoxidase (MPO) are commonly found. AASV syndromes include Wegener's granulomatosis, microscopic polyangiitis, idiopathic pauci- immune necrotizing crescentic glomerulonephritis and Churg-Strauss syndrome (CSS). AASV syndromes share some general clinical-histological manifestations, such as rapidly progressive renal failure and focal necrotizing glomerulonephritis with extracapillary proliferation in the absence (or in the presence of modest) immunoglobulins deposits (pauci- immune). Untreated AASV follow a progressive course with a fatal outcome due to vital organ failure.The combination of cyclophosphamide and prednisone is now established as the treatment of choice for patients with AASV, but there is considerable debate over the duration of therapy and the best way to administer cyclophosphamide. Treatment of AASV can be divided into two phases: an induction of remission and a maintenance of remission phase. Patients with AASV and renal involvement (serum creatinine less than 500 ml/L or 5.6 mg/dl) should be treated with a combination of oral prednisone with gradual tapering and cyclophosphamide. Once remission is achieved, usually after 3-6 months, azathioprine should replace cyclophosphamide. It is not known for how long treatment should be continued but at least one year of treatment after remission is warranted. When serum creatinine is than 500 ml/L (5.6 mg/dl) and/or oliguria is present, the addition of methylprednisolone pulses and/or plasma exchange should be considered.
Abstract: OBJECTIVE: We evaluated the prevalence and clinical significance of proteinase 3 (PR3-) and myeloperoxidase (MPO-) antineutrophil cytoplasmic antibodies (ANCA) in 115 patients with systemic sclerosis (SSc, scleroderma). METHODS: Sera were assayed by 2 independent centers, which used indirect immunofluorescence (IIF) and direct ELISA as screening tests. Inhibition-ELISA for PR3- and MPO-ANCA and PR3 capture-ELISA experiments were also performed. The clinical features of the ANCA positive were compared with those of the ANCA negative scleroderma patients. RESULTS: The IIF test revealed 5 P-ANCA positive sera (4.34%). Surprisingly, by ELISA 2 of these were PR3-ANCA positive, one was MPO-ANCA positive, and 2 were both PR3- and MPO-ANCA positive. In addition, 3 IIF negative sera were ELISA positive, 2 for PR3- and one for MPO-ANCA. ELISA results were confirmed by fluid phase inhibition experiments. Only 2 out of the 6 PR3-direct ELISA positive sera were positive by PR3-capture ELISA at low titers. Neither PR3- nor MPO-ANCA were significantly associated to any clinical feature of patients with SSc. CONCLUSION: As well as the previously described MPO-ANCA, even PR3-ANCA may be detected in some sera from patients with SSc. The IIF pattern and the negative results obtained with PR3-capture ELISA suggest that different epitopes from those recognized by vasculitis sera might be involved with PR3-ANCA in SSc, and show the importance of combining IIF and ELISA tests for ANCA detection.
Abstract: OBJECTIVE: Glomerulonephritis is a severe manifestation of systemic lupus erythematosus (SLE) that is usually treated with an extended course of intravenous (IV) cyclophosphamide (CYC). Given the side effects of this regimen, we evaluated the efficacy and the toxicity of a course of low-dose IV CYC prescribed as a remission-inducing treatment, followed by azathioprine (AZA) as a remission-maintaining treatment. METHODS: In this multicenter, prospective clinical trial (the Euro-Lupus Nephritis Trial [ELNT]), we randomly assigned 90 SLE patients with proliferative glomerulonephritis to a high-dose IV CYC regimen (6 monthly pulses and 2 quarterly pulses; doses increased according to the white blood cell count nadir) or a low-dose IV CYC regimen (6 fortnightly pulses at a fixed dose of 500 mg), each of which was followed by AZA. Intent-to-treat analyses were performed. RESULTS: Followup continued for a median of 41.3 months in the low-dose group and 41 months in the high-dose group. Sixteen percent of those in the low-dose group and 20% of those in the high-dose group experienced treatment failure (not statistically significant by Kaplan-Meier analysis). Levels of serum creatinine, albumin, C3, 24-hour urinary protein, and the disease activity scores significantly improved in both groups during the first year of followup. Renal remission was achieved in 71% of the low-dose group and 54% of the high-dose group (not statistically significant). Renal flares were noted in 27% of the low-dose group and 29% of the high-dose group. Although episodes of severe infection were more than twice as frequent in the high-dose group, the difference was not statistically significant. CONCLUSION: The data from the ELNT indicate that in European SLE patients with proliferative lupus nephritis, a remission-inducing regimen of low-dose IV CYC (cumulative dose 3 gm) followed by AZA achieves clinical results comparable to those obtained with a high-dose regimen.
Abstract: BACKGROUND: We reported previously that in renal disease in relation to antineutrophil cytoplasm auto-antibodies (ANCA)-associated vasculitis, renal outcome correlates better with the percentage of normal glomeruli than with separate active lesions. This may imply that glomeruli, once affected by necrotizing and crescentic lesions, are irreversibly damaged. We quantified and evaluated the course of renal lesions in the present study. METHODS: We retrospectively analysed 31 patients with renal disease in relation to ANCA-associated vasculitis, all treated with immunosuppressive drugs. In all patients, a renal biopsy was performed at diagnosis. A follow-up biopsy was performed in all patients on the indication of a suspected renal relapse, after a mean interval of 31 months. RESULTS: The mean percentage of normal glomeruli in the renal biopsy did not change over time (29% in the initial and 30% in the follow-up biopsy). The mean percentage of glomeruli with crescents, however, significantly decreased from 57 to 30% (P<0.001). The percentage of glomerulosclerosis significantly increased from 12 to 39% (P<0.001). The data were independent of diagnosis, gender, age, time interval between the biopsies, and treatment. CONCLUSIONS: This is the first study to quantify glomerular changes between two time points in patients with renal vasculitis. Our results suggest that, on average, no new glomeruli are recruited into the active disease process. The sum of the percentage of crescentic and sclerotic glomeruli in the initial biopsies is larger than the percentage of sclerotic glomeruli in the follow-up biopsies. Thus, therapy seems not only to prevent normal glomeruli from being recruited into the active disease process for a certain time, but seems also to allow part of the active lesions to revert into a normal phenotype, although another part of the active lesions will be transformed to a chronic phenotype.
Abstract: The "Euro-Lupus Cohort" is composed by 1,000 patients with systemic lupus erythematosus (SLE) that have been followed prospectively since 1991. These patients have been gathered by a European consortium - the "Euro-Lupus Project Group". This consortium was originated as part of the network promoted by the "European Working Party on SLE", a working group created in 1990 in order to promote research in Europe on the different problems related to this disease. The "Euro-Lupus Cohort" provides an updated information on the SLE morbidity and mortality characteristics in the present decade as well as defines several clinical and immunological prognostic factors.
Abstract: Clinical immunology laboratories play an essential role in diagnosis and monitoring of systemic lupus erythematosus (SLE). To obtain the best results in terms of diagnostic performance and clinical usefulness, the following recommendations should be fulfilled: Indirect immunofluorescence on Hep-2 cells remains the method of choice for the detection of anti-nuclear antibodies (ANA). The sensitivity of ANA test for SLE is very high (almost 100%) but its specificity low since ANA can be present in a number of different clinical conditions and even in normal controls. Anti-dsDNA antibodies are highly specific for SLE and present in a high proportion of SLE patients (40-80%). The method of choice for anti-ds DNA is the Farr assay; however, the necessity of using radioactive material decreases its applicability. As an alternative, immunofluorescence on Crithidia Luciliae can be used in the diagnostic phase for its high specificity. It is not advisable to use ELISA, in the diagnostic phase, due to its low specificity. The quantitative determination of anti-dsDNA is useful for monitoring patients, in particular in the presence of nephritis. For monitoring, a quantitative method should be used (Farr assay or ELISA). The detection of antibodies to extractable nuclear antigens (ENA) and to phospholipids (Lupus anticoagulant and anti-cardiolipin antibodies with a beta2 glycoprotein I-dependent method) are useful to identify subgroups of patients at risk for some clinical manifestations (i.e. anti-phospholipid syndrome). New assays (anti-C1q and anti-nucleosome antibodies) have been recently proposed for diagnosis (anti-nucleosome) and monitoring SLE patients (anti-C1q and anti-nucleosome antibodies), with promising results. Among biological parameters, urinary levels of monocyte chemoattranct protein 1 (MCP1) seem to be the most useful to monitor nephritis activity in lupus patients.
Abstract: OBJECTIVE: To test the prevalence of anti-neutrophil cytoplasmic antibodies (ANCA) in systemic sclerosis (SSc) and to verify a possible association of ANCA with normotensive renal involvement in SSc. PATIENTS AND METHODS: 51 patients affected by SSc, 35 with diffuse scleroderma (dSSc) and 16 with limited scleroderma (lSSc), were tested for ANCA by indirect immunofluorescence (IIF) on human ethanol and formalin-acetone-fixed granulocytes (before and after DNase treatment), by conventional enzyme linked immuno-sorbent assay (ELISA) and by capture-ELISA. RESULTS: Six out of 51 selected SSc patients had ANCA by IIF (11.7%) and five presented a perinuclear/nuclear atypical ANCA pattern. In all cases we only found anti-proteinase3 (aPR3) antibodies. All ANCA positive patients had diffuse form of SSc (17.1%), all were anti-Scl70 positive (aScl70), five patients had proteinuria, three had microscopic haematuria. All ANCA positive patients were normotensive with normal renin plasma levels, the mean erythrocyte sedimentation rate (ESR) was higher in this group compared to the other SSc patients. CONCLUSIONS: Our study shows that aPR3 is not rare in dSSc. According to the clinical and serological findings and to the recent literature, we can hypothesise that when ANCA are found in SSc, an overlapping of scleroderma with systemic necrotizing vasculitis should be suspected.
Abstract: The IgMk rheumatoid factors (RF) of type II mixed cryoglobulinaemia (MC) react, in 95% of cases, with MoAbs against the cross-reactive idiotypes (CRI) Cc1 or Lc1 (corresponding to the products of the VH1 and VH4 genes). MC is closely associated with HCV infection, a virus which infects lymphocytes and may replicate in B cells. It has been suggested that HCV may induce clonal selection of B cells producing monoclonal IgMk RF in type II MC. To verify whether HCV is enriched in B cells, and in the subsets expressing Cc1 and Lc1 CRI, we studied peripheral blood lymphocytes from eight patients with MC and HCV RNA-positive sera. Seven patients had RF reacting with anti-Cc1, the other with anti-Lc1 CRI. Total lymphocytes, T cells, B cells, and Cc1+ or Lc1+, Cc1- or Lc1- B cells were purified using MoAb-coated magnetic beads. Lymphocyte subsets were then diluted to give a range of 1 x 106-1 x 103 cells and tested for HCV RNA by reverse transcriptase-polymerase chain reaction. HCV was found exclusively in B cells in seven out of eight patients. In three patients HCV was enriched in the Cc1+ cells. In one of these patients, HCV was found exclusively in Cc1+ cells, with Cc1- cells being HCV-. The data indicate that B cells from type II MC patients are almost constantly infected by HCV. In selected cases, B cell subsets expressing IgMk RF CRI are the prevalent cell type infected by HCV. Our data suggest HCV involvement in B cell dysregulation leading to cryoprecipitable IgMk RF production.
Abstract: Among the several types of chronic glomerulonephritis (GN) described in association with hepatitis C virus (HCV) infection, cryoglobulinemic glomerulonephritis is by far the most frequent. It is usually associated with type II cryoglobulinemia with IgM k rheumatoid factor. It is a membranoproliferative GN, which shows some distinctive histologic features (intraglomerular monocyte infiltration, intraluminal thrombi due to massive precipitation of cryoglobulins, renal vasculitis), has a chronic course with acute recurrent episodes that can be controlled by corticosteroids more than by antiviral therapy (interferon alpha). More controversial is the association with type I non-cryoglobulinemic membranoproliferative GN, which has been found in some series from the USA and Japan but not in others. The demonstration of HCV antibodies and/or HCV-RNA in other types of chronic glomerulonephritis is usually reported in a small minority of cases suggesting the possibility of a coincidental finding more than an etiologic factor.
Abstract: OBJECTIVE: To study the sera from selected groups of antineutrophil cytoplasmic antibody (ANCA) positive patients by means of the indirect immunofluorescence test (ANCA-IIF) with different fixatives, in order to better discriminate among the various ANCAs (Ag-specificity and disease associations), especially those for which the antigen targets have not yet been identified. METHODS: Eighty pathological serum samples and 15 normal sera were evaluated. Pathological samples included sera from 30 ulcerative colitis (UC) ANCA positive patients, 30 P-ANCA/myeloperoxidase (MPO-ANCA) positive microscopic polyangiitis (MPA) patients, 10 C-ANCA/proteinase 3 (PR3-ANCA) positive Wegener's granulomatosis (WG) patients, and 10 antinuclear antibody (ANA) positive (ANCA negative) systemic lupus erythematosus (SLE) patients. ANCA were detected by IIF on ethanol, methanol and formalin-fixed granulocytes and by ELISAs specific for MPO, PR3, lactoferrin (LF) and bactericidal/permeability-increasing protein (BPI). Additionally, sera were tested for the presence of antinuclear antibodies on IIF. RESULTS: 96% of serum samples from UC patients, positive by IIF on ethanol-fixed granulocytes, became negative when tested on formalin-fixed neutrophil slides. On the contrary, 95% of sera from vasculitic patients showed a clear diffuse granular cytoplasmic pattern on the same substrate; sera from all 10 SLE patients did not show any reactivity when formalin was used as fixative. On methanol-fixed neutrophils, 100% of UC P-ANCA positive sera were positive with the same pattern versus only 20% of vasculitic P-ANCA positive (MPO positive). Methanol fixation had no effect on PR3-ANCA and ANA positive sera. CONCLUSION: The comparison of IIF patterns of sera tested on different fixed cells may be useful to distinguish vasculitis-related P-ANCA versus ANA and vasculitis-related P-ANCA versus UC-related P-ANCA.
Abstract: BACKGROUND: Endothelial cell damage occurs during vasculitic processes in vivo. With the alteration of the endothelium, exposure to basement membrane components may occur with induction of humoral immunity. METHODS: In the present study, we evaluated the prevalence of antibodies against the basement membrane antigen laminin (LMN) in patients with ANCA-associated systemic vasculitis (AASV), pathologic controls (systemic lupus erythematosus, mixed cryoglobulinaemia, Henoch-Schönlein purpura, primary glomerulonephritis) and normal individuals. RESULTS: By ELISA, 21.6% of AASV (16/74) and 10% of pathologic controls (3/30), but only one of the normal controls (2. 8%) had these antibodies (P=0.02). When AASV patients were divided into two groups according to diagnosis and ANCA antigen specificity, antibodies to LMN were found in 27.5% of MPO-ANCA positive microscopic polyangiitis patients (11/40) vs. only 14.7% of PR3-ANCA positive Wegener granulomatosis patients (5/34). There was no correlation between the presence or titre of anti-LMN antibodies and the main clinical and laboratory parameters. CONCLUSION: These results indicate that basement membrane antigens may become immunogenic in patients with AASV, especially in those with MPO-ANCA positivity. These antibodies are most likely the result of endothelial damage secondary to the initial inflammatory process but may well perpetuate further vascular damage in some patients.
Abstract: BACKGROUND: The aim of this study was to evaluate a) the role of bactericidal/permeability-increasing protein (BPI) as a possible antigen determining perinuclear anti-neutrophil cytoplasmic antibody (p-ANCA) reactivity in ulcerative colitis and b) the prevalence and clinical correlates of anti-BPI antibodies in patients with ulcerative colitis on the basis of their p-ANCA status. METHODS: p-ANCA and anti-BPI antibodies were evaluated by means of indirect immunofluorescence and enzyme-linked immunosorbent assay methods in a group of 112 ulcerative colitis patients (including 42 patients subjected to proctocolectomy) well defined as far as their clinical features and p-ANCA status. RESULTS: Anti-BPI antibodies were detected in 24% of non-operated patients and were significantly more frequent in p-ANCA-positive patients (32% versus 5% in p-ANCA-negative patients; P < 0.015). The prevalence of anti-BPI antibodies was similar in non-operated and operated patients and was high in men, in patients with an extensive and aggressive disease, and in patients developing pouchitis after surgery. CONCLUSIONS: These data indicate that BPI is a neutrophil antigen frequently recognized by p-ANCA-positive ulcerative colitis sera. The presence of anti-BPI antibodies appears to identify further immunologic and clinical heterogeneity in ulcerative colitis.
Abstract: Anti-neutrophil cytoplasmic antibodies (ANCA) are widely used as diagnostic markers for Wegener's granulomatosis (WG), microscopic polyangiitis (MPA), Churg-Strauss syndrome (CSS) and idiopathic rapidly progressive glomerulonephritis (iRPGN). The objective of this study was to evaluate the diagnostic value of ANCA measurement by the indirect immunofluorescence (IIF) test, and by anti-PR3 and anti-MPO ELISA performed in different locations, in patients with idiopathic small vessel vasculitis. Fourteen centers participated in a standardization study of ANCA assays, and entered a total number of 169 newly diagnosed and 189 historical patients with idiopathic systemic vasculitis or iRPGN. Patients were classified according to a pre-defined diagnostic classification system. Results were compared with those of 184 disease controls and 740 healthy controls. The IIF test was performed according to standard methodology; ELISAs had been standardized among the participants in a previous phase of the study. The sensitivities of assays in patients were as follows. The sensitivity in WG was: cANCA 64%, pANCA 21%, anti-PR3 66%, anti-MPO 24%. In MPA the sensitivity was: cANCA 23%, pANCA 58%, anti-PR3 26%, anti-MPO 58%. Sensitivity in iRPGN was: cANCA 36%, pANCA 45%, anti-PR3 50%, anti-MPO 64%. The specificity of assays (related to disease controls) was: cANCA 95%, pANCA 81%, anti-PR3 87%, anti-MPO 91%. When the results of the IIF test were combined with those of the ELISAs (cANCA/anti-PR3 positive, pANCA/anti-MPO positive), the diagnostic specificity increased to 99%. The sensitivity of the combination of cANCA + anti-PR3 or pANCA + anti-MPO for WG, MPA or iRPGN was 73%, 67% and 82%, respectively. From this study we conclude that the value of the IIF test for ANCA detection can be greatly increased by the addition of a well standardized antigen-specific ELISA. In a significant number of patients with idiopathic small vessel vasculitis, however, the ANCA test results (either in IIF or ELISA) are negative.
Abstract: BACKGROUND: The presence and the pathogenetic role of circulating IgA reacting with neutrophil cytoplasmic antigens (IgA-ANCA) in patients with Henoch-Schönlein purpura (HSP) is still debated. This study was aimed to investigate some characteristics of serum IgA and macromolecular IgA in HSP patients, focusing on IgA-ANCA. METHODS: Eighty-seven HSP patients with biopsy proved renal involvement (51 adults and 36 children) enrolled in a multicentre study of the Italian Group of Immunopathology were investigated. RESULTS: Significantly high levels of IgA immune complexes were found in both adults (P < 0.05) and children (P < 0.01), while the binding of IgA to jacalin, was significantly low in children with HSP (P < 0.01) only. Two series of ELISA were done for IgA-ANCA, in two different laboratories. Increased binding to PMN crude extracts (P < 0.01) without any modification in IgA binding to proteinase 3 was found by either specific ELISA. Conversely, the binding of IgA to myeloperoxidase (MPO) was found to be significantly (P < 0.05) increased with positive values in 25% of patients by one assay only. Three of four sera with positive IgA-MPO ANCA exhibited binding in Western-blot studies with the MPO preparation used in ELISA to a 28-kDa species. D-galactose and N-acetyl-glucosamine decreased the binding of serum IgA to MPO more in HSP than in controls (P < 0.05). CONCLUSIONS: The conflicting reports on IgA-ANCA may reflect some atypical characteristics of the reaction which can be detected only by some ELISAs. We suggest that not an antigen-antibody reaction but a lectinic interaction due to abnormal composition of IgA carbohydrate side chains may account for the IgA-ANCA reaction in patients with HSP nephritis.
Abstract: BACKGROUND: Antineutrophil cytoplasmic antibodies (ANCAs) from patients with vasculitidis can induce neutrophils to release oxygen radicals in vitro. ANCAs with a perinuclear pattern of immunofluorescence are found in most patients with ulcerative colitis, but several findings are against ANCAs having a pathogenetic role in this disease. AIMS: To evaluate the influence of ANCAs associated with ulcerative colitis on the respiratory burst activity of neutrophils. PATIENTS: Serum samples were obtained from 14 patients with ulcerative colitis, seven of whom showed positivity for p-ANCAs, three patients with vasculitidis, two with positivity for p-ANCAs, and one for c-ANCAs, and seven healthy volunteers. METHODS: A positive ANCA serology was determined with a standard indirect immunofluorescence assay. Purified immunoglobulins (IgGs) were prepared from serum samples by DEAE-Affigel blue chromatography. Human neutrophils were prepared by dextran-Ficoll-Hypaque separation. Superoxide anion (O2-.) generation was measured by following the superoxide dismutase inhibitable reduction of ferricytochrome. RESULTS: There were no significant differences among samples from ulcerative colitis IgG p-ANCA positive, ulcerative colitis IgG p-ANCA negative patients, and controls on O2-. production, whereas ANCA positive IgG from vasculitidis significantly enhanced O2-. release (p < 0.001). CONCLUSIONS: p-ANCAs associated with ulcerative colitis have no effect on the respiratory burst activity of normal human neutrophils in vitro. These results reinforce the hypotheses that ANCAs are unlikely to contribute to the pathogenesis of ulcerative colitis.
Abstract: A high incidence of alpha 1-antitrypsin (AAT) deficiency has been reported in patients with C-ANCA systemic vasculitis in association with antibodies against proteinase-3 (PR3). To clarify the role of AAT deficiency in the acute vasculitic process as well as in progression of the disease, we studied 84 patients with either C-ANCA or P-ANCA vasculitis with special reference to: (a) the AAT gene, (b) the phenotypic (Pi) variants and (c) the serum levels during both acute illness and remission. The PiZ gene was found in six patients (8% vs. 1.5% controls) irrespective of the type of autoantibodies (C-ANCA vs. P-ANCA). All PiZ patients displayed the ability to raise their AAT serum levels up to the normal range during acute illness. In contrast, 24 patients with the PiM phenotype presented low AAT serum levels during acute illness. In all these patients, the AAT levels returned to normal values during the remission. Low AAT levels were associated with low levels of C-reactive protein (PCR) (P < 0.001), with a less severe renal involvement or a minor risk of death, and, in one tested patient, with a novel point mutation (TCGA-->TCAA) at the enhancer-promoter region of the AAT gene. Low AAT serum levels did not correlate with either type/titre of autoantibody or distribution/severity of the vasculitis process. In the case-control study, high AAT levels emerged as a major determinant of progression towards end-stage renal failure [odds ratio 3 (95% CI 1.1-8.4)]. These results indicate: (a) a high incidence of the PiZ gene of AAT in systemic vasculitis irrespective of the type of autoantibodies; (b) a novel form of AAT deficiency associated with the normal PiM phenotype becoming manifest only during acute illness; (c) dysregulation of the acute-phase response affecting selectively AAT or both AAT and PCR; (d) correlation between low plasma levels of AAT and less severe renal involvement or risk of death.
Abstract: BACKGROUND: ANCA are thought to play a pathogenic role in renal vasculitis. ANCA may also be detected in patients with diseases not usually associated with renal pathology, such as ulcerative colitis. Our study was conducted to determine if the presence of ANCA in patients with ulcerative colitis is associated with renal pathology. METHODS: Eight ANCA-positive and five ANCA-negative patients with a histological and endoscopic diagnosis of active ulcerative colitis were investigated. Repeated complete urinalyses and determination of microalbuminuria and creatinine clearance were performed. Serum IgG and IgA ANCA were evaluated in all patients by indirect immunofluorescence and ELISA, and when detected the antibodies were further characterized by alpha granules preparation, myeloperoxidase, lactoferrin, and cathepsin G. RESULTS: In both ANCA-positive and ANCA-negative patients renal function was normal or near normal and urinalyses (including microalbuminuria) failed to disclose any abnormalities. ANCA exhibited a perinuclear pattern in all ANCA-positive patients. Interestingly, none of the ANCA-positive patients had antibodies to myeloperoxidase or to alpha granules which are usually found in the sera of patients with ANCA-associated vasculitis, and only one had antibodies to lactoferrin. The ANCA specificity remained undetermined in the remaining seven patients. At the end of the 1-year observation period, all ANCA-positive patients remained ANCA-positive without developing symptoms, signs or laboratory abnormalities consistent with renal involvement. CONCLUSIONS: Renal damage was not observed in ANCA-positive patients with ulcerative colitis even after 1 year of follow-up, suggesting that the ANCA found in these patients do not share the antigenic targets with the ANCA commonly found in renal vasculitis. Therefore the potential of ANCA of inducing renal lesions (if any) is dependent on their own antigenic specificity.
Abstract: Anti-neutrophil cytoplasmic antibodies (ANCA) are diagnostic markers for systemic vasculitis. They are classically detected by an indirect immunofluorescence test using normal donor neutrophils as substrate. This assay lacks antigenic specificity and is not quantitative. The 'EC/BCR Project for ANCA Assay Standardization' is an international collaboration study with the aim to develop and standardize solid phase assays for ANCA detection. In this part of the study the isolation and characterization of proteinase-3 and myeloperoxidase, the two main target molecules for ANCA, and the development and standardization of ELISAs with these antigens are described. Six laboratories successfully isolated purified proteinase-3 preparations that could be used. Three of these preparations, together with one myeloperoxidase preparation, were subsequently used for ANCA testing by ELISA. The ELISA technique was standardized in two rounds of testing in the 14 participating laboratories. The coefficient of variation of these new assays decreased from values of approx. 50% in the first round to approx. 20% in the second round. We conclude that purified proteinase-3 and myeloperoxidase can be used in standardized ELISAs for ANCA detection. Whether such procedures offer advantages over the IIF test will be determined in a prospective clinical study.
Abstract: MHC Class II genes may contribute to susceptibility to IgA nephropathy (IgAN). We have previously identified a restriction fragment length polymorphism (RFLP) of the DQB1 region that associated with IgAN in British Caucasoids. However, another group, while demonstrating a DQB1 association, was unable to confirm our finding. MHC molecules are heterodimers consisting of an alpha and beta chain, and thus polymorphism of the DQA1 alpha chain may also be important to disease pathogenesis in IgAN. Therefore, we have determined DQA1 alleles and re-examined DQB1 alleles in British Caucasoids with IgAN using an approach that can differentiate between the common DQ alleles; we have also extended our studies to Caucasoid populations from Northern and Southern Europe, thereby addressing the possibility of variation in genetic susceptibility between populations. DNA was prepared from IgAN patients (British, N = 105; Italian, N = 71; Finnish, N = 48) and healthy controls (British, N = 111; Italian, N = 63; Finnish, N = 41). DQA1 alleles were identified by TaqI RFLP and Southern blotting; alleles that could not be fully resolved by Taq Southern blotting were identified by PCR-RFLP. DQB1 alleles were identified by polymerase chain reaction (PCR) based technique (PCR-RFLP). No consistent association of DQ alleles were found between the populations studied. In British patients a decreased frequency of DQB1*0201 was observed (P = 0.008), in Finnish patients a decreased frequency of DQB1*0602 was observed (P = 0.01), and in Italian patients no association between DQ markers and IgAn was found. These data demonstrate population variation in disease association, but no strong or consistent association in the DQ region.
Abstract: In our previous experimental work we suggested that the frequent nephritogenicity of type II cryoglobulins could depend on a particular affinity of the immunoglobulin (Ig) M kappa rheumatoid factor (RF) component for mesangial matrix. Since cellular fibronectin (cFN) in the human kidney is mainly represented in glomerular mesangium, we studied the binding capacity to cFN of IgM kappa RFs from type II cryoglobulins compared with other different monoclonal and polyclonal IgM and IgM RFs. We purified 13 IGM kappa from human IgM kappa/IgG cryoglobulins, eight monoclonal IgM from patients with Waldenström's macroglobulinemia, nine polyclonal IgM from normal donors, and eight polyclonal IgM RFs from patients with rheumatoid arthritis. Purified IgM were used at the same concentration in enzyme-linked immunosorbent assay (ELISA) on cFN-coated plates. All the cryoglobulin IgM showed high specific binding to cFN while IgM from Waldenström's macroglobulinemia, normal IgM, and polyclonal IgM RFs had low or absent binding. These data were confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of cFN followed by Western blot analysis with purified IgM. The IgM kappa binding to cFN persisted using IgM kappa monomers, and was inhibited by cFN but not by plasma FN in a specific inhibition test. Further enzyme-linked immunosorbent assay studies showed that cryoglobulin IgM kappa RFs are still able to bind IgG in a dose-dependent manner once linked to solid-phase cFN. The data suggest that the affinity of cryoglobulin IgM kappa RFs for immobilized cFN could be involved in the particular high nephritogenicity of type II cryoglobulins and might lead to in situ immune complex formation.
Abstract: OBJECTIVE: To elucidate the role of anti-endothelial cell antibodies (AECA) in vascular inflammation in patients with Wegener's granulomatosis (WG). METHODS: IgG fractions from 3 AECA-positive WG patients, IgG from 3 AECA-negative WG patients, and IgG from healthy donors were tested for their ability to: a) bind to endothelial cells and to display complement-dependent or antibody-dependent cellular cytotoxicity, b) modulate cell membrane expression of adhesion molecules, as evaluated by cytofluorometry and by immunoenzymatic assay, and c) induce the secretion of interleukin-1 beta (IL-1 beta), IL-6, IL-8, and monocyte chemotactic protein 1 (MCP-1). RESULTS: We found that AECA IgG from WG patients do not display any significant cytotoxicity but are able to up-regulate the expression of E-selectin, intercellular adhesion molecule 1 and vascular cell adhesion molecule 1 and to induce the secretion of IL-1 beta, IL-6, IL-8, and MCP-1. CONCLUSION: AECA in patients with WG could play a potential pathogenetic role by activating endothelial cells, and thus facilitating leukocyte recruitment and adhesion to endothelial surfaces, rather than by displaying a cytotoxic activity.
Abstract: The term 'vasculitides' encompasses a group of inflammatory disorders which may affect the kidney by damaging its blood supply. Although the kidney may be affected by many types of systemic vasculitis, renal involvement is particularly frequent in some forms of systemic necrotizing vasculitis which are considered primary, such as Wegener's granulomatosis and microscopic polyarteritis, including its 'renal-limited' variant. Renal vasculitis can occur at any age, but is seen particularly frequently in middle-aged and elderly subjects, in whom clinical presentation and prognosis are significantly worse. In addition to the specific problems related to age, this review focuses on a few aspects that are still the subjects of debate: classification, the role of ANCA, renal pathology and the treatment of renal vasculitis.
Abstract: Shared idiotype specificities (CRIs) among monoclonal IgM rheumatoid factors from patients with essential mixed cryoglobulinemia have been demonstrated with the use of polyclonal antisera and have been confirmed, more recently, using monoclonal antibodies. In this paper we will summarize some of the work that has been performed in our laboratory using anti-idiotypic monoclonal antibodies. Such reagents allowed us to detect CRIs on cryoprecipitable rheumatoid factors, to detect idiotype-positive cells in bone marrow and peripheral blood, and to identify glomerular immune deposits.
Abstract: Several studies have established a strong association between hepatitis C virus (HCV) infection and essential mixed cryoglobulinemia (EMC). However, the mechanisms by which HCV infection may result in cryoglobulinemia in some patients but not in others remain unknown. In this paper we shall summarize some of the work done in our laboratories on certain aspects of HCV in patients with EMC.
Abstract: We studied 54 patients with essential mixed cryoglobulinaemia (EMC), (23 males, 31 females) mean age 61 years (range 28-77). Forty-one (76%) had type II cryoglobulinaemia and 13 (24%) type III. Antibodies to HCV were detectable by second-generation ELISA in 49 patients (91%) with confirmed or indeterminate RIBA results. HCV RNA was detected by RT PCR using 5' UTR nested primers; HCV genotypes 1a, 1b, 2 and 3a were identified by genotype-specific core-region nested primers. All patients (49) with antibodies to HCV in their serum were HCV-RNA positive; 27 (55.1%) had HCV subtype 1b and 21 (42.8%) type 2. In one patient the HCV genotype could not be determined. The genotype distribution was not different from that found in patients with chronic hepatitis C without cryoglobulinaemia. However, the presence of HCV subtype 1b correlated significantly with signs of chronic hepatitis and presence of peripheral neuropathy. Severity of disease tended to be worse in patients infected with HCV subtype 1b, but this was mainly due to liver disease. HCV genotypes may influence the clinical expression and, in particular, the severity of liver involvement in patients with EMC. Extent and severity of EMC disease in general may also be affected by the different HCV genotypes. These findings may have therapeutical implications, since the different HCV genotypes respond differently to interferon treatment.
Abstract: Despite the availability of different classifications for rapidly progressive glomerulonephritis (RPGN), patients with "idiopathic crescentic GN" have not been yet inserted as a precisely defined subgroup, pointing to their probable heterogenicity. Trying to better define their characteristic, we retrospectively analyzed the clinical, histological and immunopathological features of 41 patients diagnostically labelled "idiopathic RPGN" because they had no evidence of systemic disease (including systemic vasculitis), no anti-GBM mediated glomerulonephritis and no clearly defined primary glomerulopathy. Starting by a thorough morphological review, 2 subgroups were defined: group I (25 patients) with variable degrees of intraglomerular necrosis, and group II (16 patients) with no intracapillary necrotizing lesions. Group I showed no or minimal endocapillary proliferation, intense interstitial infiltrates with periglomerular localization, frequent ruptures of Bowman's capsule and mild degree of glomerular and/or interstitial sclerosis. 16 patients in this group (64%) had irregular deposits of complement C3 at immunofluorescence while the remaining 9 (36%) had no immune deposits. Clinically they had no previous history of preceding urinary abnormalities, had a mean of 1.8 g/day proteinuria and a positivity for ANCA in 92% (12/13). In group II there was frequently marked mesangial proliferation, scarce interstitial infiltrates, no ruptures of Bowman's capsule and marked degrees of glomerulosclerosis and interstitial fibrosis. All patients in this group had clearly defined immune deposits of C3 and/or IgG. Clinically 50% of these patients had a history of recurrent microhematuria and/or proteinuria, a mean of 4.5 g/day proteinuria and negativity for ANCA in all 8 patients tested.(ABSTRACT TRUNCATED AT 250 WORDS)
Abstract: We studied the prevalence of perinuclear antineutrophil cytoplasmic antibody (p-ANCA), as detected by immunofluorescence, in 290 Italian subjects. One hundred and two were affected by ulcerative colitis, 48 by Crohn's disease, 40 by gluten-sensitive enteropathy and 100 were normal subjects. The prevalence of p-ANCA was significantly higher in ulcerative colitis patients (45.1%) as compared to Crohn's disease patients (4.8%), gluten-sensitive enteropathy (0%) and normal subjects (1%; p < 0.0001 ulcerative colitis vs. all other groups). In this setting, the overall specificity of the test was 98.1% with a sensitivity of 45.1%. The specificity slightly decreased to 95.1% when ulcerative colitis patients were compared to patients with Crohn's colitis. In our series, p-ANCA appeared to be more prevalent in ulcerative colitis patients with more aggressive disease. ELISA experiments performed in order to identify the putative antigen(s) recognized by p-ANCA-positive sera showed that 8 of 12 sera positive at immunofluorescence reacted with at least one of the neutrophil preparations tested. The reactivities were directed towards various neutrophil preparations. Preabsorption with the specific antigen recognized by ELISA significantly inhibited the p-ANCA immunofluorescence reactivity indicating that p-ANCA reactivity might derive from the recognition of heterogeneous neutrophil-associated antigens.
Abstract: To verify whether IgA antineutrophil cytoplasmic antibody (ANCA) represents a serologic marker in Henoch-Schönlein purpura (HPS), we examined sera from 41 patients with the disease. Control sera from 28 patients with primary IgA nephropathy (IgA-N), 26 IgG-ANCA-positive vasculitis, and 28 normal controls were also studied. An increased IgA binding to neutrophil cytoplasmic extracts but not to purified ANCA antigens was found in 12.2-14.6% of HSP patients and in 14.3-21.4% of IgA-N patients versus 3.5% of normal controls. IgA binding to neutrophil cytoplasmic extracts correlated with serum IgA levels, IgA-rheumatoid factor, and IgA-fibronectin binding capacity. Moreover, low amounts of IgG and fibronectin were detected as contaminants in neutrophil cytoplasmic extracts and fibronectin could partly inhibit the binding of IgA to "crude" extracts. We conclude that IgA-ANCA are neither diagnostically nor immunologically specific in HSP and IgA-N. Several factors present in the sera of patients with IgA-related nephropathies seem to contribute to the "false-positive" IgA-ANCA demonstrable in these patients.
Abstract: Results of immunological studies on skin biopsies of 5 patients with Sneddon's syndrome are reported. Also studied were coagulation factors and autoantibodies believed to play a role in this syndrome. Hemostasis was normal except for a mild increase of fibrinogen in one subject; lupus anticoagulant (LAC) and anticardiolipin antibodies were negative in all. The skin biopsies ruled out systemic vasculitis and vasculitis in association with connective tissue diseases. Sneddon's syndrome is a peculiar clinicopathological condition, probably with several etiologies, but is distinct from primary antiphospholipid syndrome.
Abstract: The following are some of the conclusions and proposals made at the Chapel Hill Consensus Conference on the Nomenclature of Systemic Vasculitis. 1. Although not a prerequisite component of the definitions, patient age is recognized as a useful discriminator between Takayasu arteritis and giant cell (temporal) arteritis. 2. The name "polyarteritis nodosa," or alternatively, the name "classic polyarteritis nodosa," is restricted to disease in which there is arteritis in medium-sized and small arteries without involvement of smaller vessels. Therefore, patients with vasculitis affecting arterioles, venules, or capillaries, including glomerular capillaries (i.e., with glomerulonephritis), are excluded from this diagnostic category. 3. The name "Wegener's granulomatosis" is restricted to patients with granulomatous inflammation. Patients with exclusively nongranulomatous small vessel vasculitis involving the upper or lower respiratory tract (e.g., alveolar capillaritis) fall into the category of microscopic polyangiitis (microscopic polyarteritis). 4. The term "hypersensitivity vasculitis" is not used. Most patients who would have been given this diagnosis fall into the category of microscopic polyangiitis (microscopic polyarteritis) or cutaneous leukocytoclastic angiitis. 5. The name "microscopic polyangiitis," or alternatively, "microscopic polyarteritis," connotes pauci-immune (i.e., few or no immune deposits) necrotizing vasculitis affecting small vessels, with or without involvement of medium-sized arteries. Cryoglobulinemic vasculitis, Henoch-Schönlein purpura, and other forms of immune complex-mediated small vessel vasculitis must be ruled out to make this diagnosis. 6. The name "cutaneous leukocytoclastic angiitis" is restricted to vasculitis in the skin without involvement of vessels in any other organ. 7. Mucocutaneous lymph node syndrome must be present to make a diagnosis of Kawasaki disease.(ABSTRACT TRUNCATED AT 250 WORDS)
Abstract: In a prospective multicentre study on the clinical significance of ANCA in renal diseases, sera from 920 patients with rapidly progressive renal failure and/or renal disease in association with extrarenal signs suggestive of a systemic vasculitis were tested for the presence of ANCA by indirect immunofluorescence (IIF) and ELISA. 193 of 920 cases (20.9%) were positive by IIF and 180 (19.5%) by ELISA, using a 'crude' cytoplasmic extract as substrate. The sensitivity and specificity of IIF for 'pauci-immune' cresentic necrotizing GN (CNGN), in association or not with systemic vasculitis, was 87.5 and 95.6% respectively. The IIF pattern and antigen specificity (alpha granules and MPO) correlated well with the clinical features: a cANCA pattern (alpha granules) was associated with ENT involvement (probable Wegener's granulomatosis); a pANCA pattern (MPO) with 'idiopathic' CNGN and small-vessel vasculitis without respiratory tract disease (microscopic polyarteritis); patients with a pulmonary-renal syndrome had either c or pANCA in a similar proportion. Our study confirms a high sensitivity and specificity of ANCA for patients with CNGN. ANCA should be considered an important diagnostic test in patients with renal diseases, especially in the presence of rapidly progressive renal failure.
Abstract: This study describes the results of phase I of an international effort to develop and standardize assays for the detection of anti-neutrophil cytoplasmic antibodies (ANCA). 12 sera, four of which were selected for their potential to cause problems in the detection of various ANCA specificities, were analyzed in the standard indirect immunofluorescence (IIF) test and in ELISAs for ANCA routinely performed in the seven participating laboratories. The IIF methodology differed with respect to the dilution of the serum being screened and the concentration of the conjugate used. Results from sera with high ANCA titers were similar, although the quantitative values could not be compared. In sera containing rheumatoid factor and anti-nuclear antibodies (ANA), ANCA-unrelated staining patterns were observed. Six antigen preparations were used in ELISA for the detection of cANCA. In ELISA with purified proteinase-3 all three cANCA sera were positive, but not anti-myeloperoxidase (MPO) or anti-lactoferrin (LF) positive sera. The other assays were less sensitive or gave inconsistent results. Various preparations of purified MPO and LF used in ELISA were readily recognized by anti-MPO and anti-LF positive sera. From this study it can be concluded that the IIF test, although performed with different methods, shows comparable results using strongly positive sera. In general solid phase assays for cANCA detection are not well standardized and need improvement although the purified proteinase-3 ELISA is possibly an exception. MPO and LF can be used in ELISA procedures for the detection of pANCA-related antibodies.
Abstract: BACKGROUND: Human cryoglobulinemia is sometimes associated with glomerulonephritis (GN) due to deposition of cryoglobulins (cryos). To see whether human cryos can induce GN in mice and to study time-related changes of glomerular lesions and possible factors of cryos' nephritogenicity, we developed an experimental passive model of cryoglobulinemic GN. EXPERIMENTAL DESIGN: Two cryos IgMk-IgG from 2 patients with active GN (OLD and SOR), 2 cryos IgMk-IgG (TAC and GRO) and 1 IgM lambda (CHI) from 3 patients without GN were purified, solubilized at 37 degrees C and injected intravenously into BALB/c mice, 4 mg, twice a day. To study the possible factors of cryo nephritogenicity, we analyzed: (a) the presence, amount, and size of complexed IgMk-IgG at 37 degrees C by fast flow liquid chromatography; (b) the Cc1 or Lc1 subclass of rheumatoid factors; (c) the isoelectric points of the IgMks; (d) The proportion of IgG subclasses in cryos. RESULTS: On day 1 from the beginning of intravenous injections, cryos OLD had induced mesangial deposits of human IgM, human IgG, mouse C3 and mesangial hypercellularity. On day 2, phagocytizing cells were found along with massive endoluminal and subendothelial deposits of IgM, IgG, and C3. On day 6, perivascular infiltrates of mononuclear cells were also seen. Cryos SOR induced a similar but milder form of GN. After administration of purified OLD IgMk, OLD IgG, GRO IgMk or GRO IgG, only OLD IgMk was deposited in the mesangium. Analysis of all the cryos revealed that: the amount of complexed IgMk-IgG at 37 degrees C was always less than 1% of cryos; Cc1 and Lc1 idiotypes were not related to the nephritogenicity of cryos, the isoelectric points of IgMks were 4.5 to 5.5 and IgG1 was the prevalent subclass. CONCLUSIONS: Data demonstrate that human cryos from patients with GN can induce GN in mice that resembles the corresponding human pathology. The affinity of IgMk for glomeruli and the unexpectedly small amounts of IgMk-IgG complexes at 37 degrees C suggest that there is a role of in situ binding in nephritogenicity which is independent of the isoelectric point, rheumatoid factor idiotype, or IgG subclass.
Abstract: Antibodies to lactoferrin were detected in about 20% of patients with SLE, irrespective of the presence of renal involvement and in 10% of patients with rheumatoid arthritis and in 19% of patients with scleroderma. We conclude that anti-lactoferrin antibodies may be found in different types of connective tissue disease. Their clinical significance in these diseases however remains to be elucidated.
Abstract: Anti-myeloperoxidase (MPO) antibodies are frequently encountered in patients with vasculitis. Using a competitive inhibition ELISA test and immunoblotting, we suggest that anti-MPO antibodies might represent a heterogenous group of auto-antibodies directed against different conformational epitopes of MPO molecule.
Abstract: Recently, the induction of SLE in naive mice employing monoclonal anti-DNA antibodies (anti-DNA Ab) carrying the pathogenic idiotype 16/6 (16/6 Id) has been reported. In the current study we report on the induction of experimental SLE by polyclonal IgG anti-DNA Ab derived from a patient with active SLE and carrying the 16/6 Id. Two different experiments were conducted in which BALB/c mice were immunized in the footpads with 1 microgram/ml or 5 micrograms/ml of anti-DNA Ab. The first experiment showed the appearance in the immunized mice of high titre anti-DNA Ab together with antinuclear antibodies, alopecia and proteinuria. In the second experiment we compared, as immunizing agents, 16/6 positive anti-DNA Ab and 16/6 negative anti-tetanus toxoid antibodies (anti-TT Ab) obtained from the serum of the same patients. Our results show that only mice immunized with 16/6 positive antibodies produced anti-DNA Ab, while mice immunized with anti-TT Ab did not show any DNA-binding activity but, surprisingly, developed high titre anti-cardiolipin antibodies.
Abstract: In order to clarify if "idiopathic" RPGN still exists as a distinct entity we reviewed 41 patients with histological picture of diffuse crescentic GN (60% of crescents) and no clinical evidence of systemic disease. According to the presence or absence of intraglomerular necrotizing lesions we subdivided the patients into two different morphological groups: Group I (25 pts) with necrotizing GN and massive periglomerular infiltrates; Group II (16 pts) with intra-extracapillary proliferation and no interstitial infiltrates. Our data suggest that "idiopathic" RPGN does not exist as a distinct entity, but is an expression either of renal limited vasculitis or crescentic GN complicating primary proliferative GN.
Abstract: In the last few years many investigators have reported the recurrence of primary IgA nephropathy (IgAN) or the presence of persistent microhaematuria and/or proteinuria in family members of patients with IgAN. Our study was undertaken to investigate the relevance of abnormalities in the regulation of the IgA and IgM immune system in microhaematuric and asymptomatic family members of IgAN patients. Fifty-four out of 120 members of nine unrelated pedigrees were examined by urinalysis; polymeric IgA (pIgA), IgA rheumatoid factor (IgARF), IgA1-IgG immune complexes (IgA 1-IgG IC) and IgA 1-IgM IC, and other immunoglobulins were measured in serum samples. Moreover, we studied the production of immunoglobulins, pIgA and IgARF by peripheral blood mononuclear cells (PBMC) in basal conditions and after pokeweed mitogen (PWM) stimulation. Our data demonstrate that persistent microhaematuria was present in 24% of relatives. High serum levels of IgA, mainly pIgA and IgARF, IgA 1-IgG IC and IgA 1-IgM IC occurred in 66% of relatives. Abnormal spontaneous production of IgA by PBMC and after PWM stimulation was present in 64% of family members. Interestingly, high serum levels of IgM and abnormal production of this immunoglobulin by PBMC were observed in relatives. However, the immunological abnormalities did not correlate in any way with the presence of urinary abnormalities such as microhaematuria, which was most likely determined by an underlying glomerular alteration.
Abstract: The prevalence and clinical significance of antineutrophil cytoplasmic antibodies with specificity for lactoferrin was determined in patients with renal diseases. Antilactoferrin antibodies were found in only 12 of 920 patients (1.3%). These patients had either "pauci-immune" necrotizing crescentic glomerulonephritis (three cases) or lupus nephritis (nine cases). To verify whether antilactoferrin antibodies were specific for patients with systemic lupus erythematosus (SLE) and renal involvement, we studied 61 additional lupus patients, 40 with active lupus nephritis and 21 with active SLE and no renal involvement. Antilactoferrin antibodies were found in approximately 15% to 20% of patients with SLE, irrespective of the presence of renal involvement. We conclude that antineutrophil cytoplasmic antibodies with specificity for lactoferrin are only sporadically found in patients with renal diseases; these patients have either necrotizing crescentic glomerulonephritis or lupus nephritis. However, antilactoferrin antibodies are not a marker for renal involvement in SLE.
Abstract: In an uncontrolled trial, patients with IgA nephropathy (IgAN) were treated with drugs that can alter the intestinal mucosal permeability to food antigens. These drugs are known to ameliorate urinary abnormalities and histological lesions of IgAN associated with ulcerative colitis or Crohn's disease [5-aminosalicylic acid (5-ASA)] or to prevent, in mice, the induction of IgAN-like disease by oral immunization [disodium cromoglycate (SCG)]. Nine patients [serum creatinine (s-Cr) less than 2 mg/dl; 24-hour proteinuria higher than 1.5 g, but not nephrotic) were treated with 5-ASA (2.4 g/day for 6 months); 9 similar patients were treated with SCG (400 mg/day for 6 months); the follow-up extended to 6 months after stopping therapy. The 5-ASA group showed a slight but not significant decrease in s-Cr, 24-hour/proteinuria, IgA circulating immune complexes (IgA-CIC) and IgA rheumatoid factor (IgA-RF); serum beta 2-microglobulin and serum IgA were unchanged; 2 of 9 treated patients showed, after 6 months of therapy, a reduction in proteinuria of more than 50% that lasted for the subsequent 18 months. The SCG-treated group showed a slight but not significant increase in 24-hour proteinuria and a significant decrease in serum IgA; unchanged were s-Cr, IgA-CIC, IgA-RF, serum beta 2-microglobulin; no patient treated with SCG showed a reduction in proteinuria of more than 50%. At the dosages and for the periods used, 5-ASA and SCG did not show a significant influence on clinical and laboratory parameters of disease in IgAN; other trials with increased dosages are warranted to definitely ascertain the possible therapeutic role of these drugs in IgAN.
Abstract: Twenty-eight out of 62 patients with Wegener's granulomatosis and micropolyarteritis display circulating antiendothelial cell antibodies (AECA) detectable by a cell surface radioimmunoassay. These antibodies do not induce an in vitro endothelial damage either alone or in the presence of fresh complement; however, 50% of IgG-AECA positive sera can be cytotoxic in the presence of human normal peripheral blood mononuclear cells (PBM) at high effector/target ratios. The specificity of the PBM-mediated cytotoxicity is supported by the absence of the phenomenon in AECA negative sera, by the disappearance of the lytic effect after absorption of AECA, and by the finding that cellular-mediated cytotoxicity can be reproduced by purified IgG-AECA positive fractions. On the contrary, polymorphonuclear leukocytes or adherent mononuclear cells are not involved in such a cytotoxic activity. AECA seem to be directed against determinants consitutively expressed on the endothelial surface since the activation of endothelial cells by interleukin-1 beta or interferon-gamma affects neither the antibody binding nor their ability to mediate 51Cr release in the presence of PBM. These findings favor the hypothesis for a possible direct pathogenetic role of circulating AECA in the in vivo vascular damage.
Abstract: Many features suggest that a genetically mediated abnormality of the IgA immune response is central in the pathogenesis of IgA nephropathy (IgAN). Candidate disease susceptibility genes include those encoding the MHC class II antigens, HLA-DR, -DQ, and -DP, and we have recently described an HLA-DQB1 association in IgAN. Polymorphisms of the HLA-DP region loci have been shown to associate with autoimmune diseases which share immunological features with IgAN; coeliac disease (CD) and dermatitis herpetiformis (DH). We have therefore examined restriction fragment length polymorphisms (RFLPs) of the DP alpha and DP beta chain genes (DPA1 and DPB1 respectively) in IgAN, and have studied three caucasoid populations (North, Mid, Southern Europe) to determine whether ethnic variation in genetic susceptibility exists. DNA was extracted from blood (IgAN, UK n = 89, Italy n = 75, Finland n = 49; Controls, UK n = 99, Italy n = 54, Finland n = 45), and studied by Southern blot hybridization techniques using the restriction enzymes BgI II and Msp I and cDNA 32P-labelled DPA1 and DPB1 probes respectively. The frequency distribution of the DPA1 and DPB1 fragments was similar between the three caucasoid IgAN patient groups compared to their respective controls. There was no association of DPA1 or DPB1 RFLPs with clinical features. These results suggest that HLA-DP region genes are not important in conferring disease susceptibility to IgAN and do not influence clinical disease expression. Moreover, different immunogenetic mechanisms operate in IgAN, CD, and DH.
Abstract: In order to study disease mechanisms and potential forms of therapy in glomerulonephritis, a model of experimental autoimmune glomerulonephritis (EAG) has been developed in the rat. We have examined the response of Brown-Norway (BN) rats to a single i.m. injection of collagenase-solubilised homologous (Sprague-Dawley, SD) or isologous (BN) glomerular basement membrane (GBM), with and without complete Freund's adjuvant (CFA). There was a dose-dependent circulating anti-GBM antibody response to all preparations of rat GBM. Animals given either antigen alone at a dose of 2 mg/kg developed circulating anti-GBM antibodies, which reached peak values by 6 weeks (63 +/- 5% following SD GBM; 53 +/- 8% following BN GBM), but did not develop glomerular deposits of IgG or nephritis. Animals given 2 mg/kg SD GBM in CFA developed greater concentrations of anti-GBM antibody by 6 weeks (122 +/- 20%) together with linear deposits of IgG on glomerular and tubular basement membranes (TBM), albuminuria (mean 7 mg/24 h), and variable focal segmental necrotising glomerulonephritis with mild interstitial nephritis. The same dose of BN GBM in CFA produced similar concentrations of circulating antibody (144 +/- 26%), with linear deposits of IgG on GBM but rarely TBM, little albuminuria, and variable mild focal glomerulonephritis. Other strains injected with SD GBM in CFA showed a variable circulating anti-GBM antibody response, which was similar to that of BN rats in PVG and DA rats but lower in LEW and WAG rats. Linear deposits of IgG on the GBM were detected in a proportion of PVG and DA rats, but not in LEW or WAG rats.(ABSTRACT TRUNCATED AT 250 WORDS)
Abstract: Anti-endothelial cell antibodies (AECA) have been detected by cell surface radioimmunoassay in nine out of 15 patients with micropolyarteritis (MPA) and in two out of five patients with Wegener's granulomatosis. AECA mostly belonged to the IgG isotype and were present in the active phase of the diseases. These antibodies were not detectable in 10 sera from patients with essential mixed cryoglobulinaemia, suggesting that they were not a mere epiphenomenon consequent to the inflammatory vascular injury. The binding activity was not related to ABH antigens or to HLA class I antigens displayed by resting human endothelial cells in culture and was not influenced by removing immune complexes. Absorption of the anti-neutrophil cytoplasmic antibodies (ANCA), present in MPA and Wegener's granulomatosis sera, did not affect the endothelial binding. AECA-positive sera did not display lytic activity against endothelial cells, neither alone nor after addition of fresh complement or normal human peripheral blood mononuclear cells. Although AECA are not cytolytic for endothelial cell monolayers in vitro, the reactivity against intact endothelial cells suggests their possible involvement in in vivo pathological processes affecting vascular structures in small vessel primary vasculitides.
Abstract: Much evidence suggests that primary IgA nephropathy (IgAN) and idiopathic membranous nephropathy (MN) are immune complex mediated diseases. Moreover, genetic factors may play an important role in their pathogenesis. Recently, restriction fragment length polymorphisms (RFLPs) of the immunoglobulin heavy chain genes have been described which appear to associate with glomerulonephritis. We have studied RFLPs of the switch region of the IgM (S mu) and IgA1 (S alpha 1) heavy chain in MN and IgAN. DNA obtained from British Caucasoids with IgAN (N = 75), MN (N = 43), and normal controls (N = 73), was digested with the restriction enzyme Sac1, and studied using Southern blot techniques and hybridization with a 32P labelled DNA probe homologous to S mu. This probe detects RFLPs at the S mu and S alpha 1 loci. The genotypic and allelic frequencies of the S mu and S alpha 1 alleles in IgAN and MN was similar to normal controls. Caucasoid subjects with IgAN from Northern and Southern Europe (Finland and Italy, respectively) were also studied to determine whether an ethnic variation in genetic susceptibility to IgAN exists. The frequency of the S mu and S alpha 1 alleles was similar between the patient groups and their respective local healthy controls. These results do not support the recent findings of an association with RFLPs of the S mu and S alpha 1 loci in IgAN and MN, and suggest that the immunoglobulin heavy chain switch region genes are not important in conferring disease susceptibility to IgAN or MN.
Abstract: A solid-phase ELISA was used to detect IgA1 immune complexes (IgA1 ICs) containing IgG and IgM in 38 serum samples from 30 patients with primary IgA nephropathy (IgAN) and 14 subjects with non-IgA chronic glomerulonephritis. A jackfruit lectin, jacalin, was used as the substrate for the selective binding of human IgA1 ICs in serum PEG precipitate (7%). The presence of IgG, A and M antibodies against the F(ab')2 region of IgG was also investigated by the solid-phase ELISA. Six patients were studied during remission and relapse (fever, upper respiratory tract infection and macroheamaturia). The results showed significant increases in serum levels of IgA1 ICs (P less than 0.001) in 39.4% of the IgAN patients, IgA1-IgG ICs (P less than 0.001) in 68.4%, and IgA1-IgM ICs (P less than 0.002) in 10.5% of the patients. A significant increase in IgA1-IgG ICs was observed during relapse (P less than 0.02). Significantly high values of IgG (P less than 0.003) and IgA (P less than 0.001) antibodies directed at the F(ab')2 region of IgG were found. A significant increase in anti F(ab')2 antibodies (class IgA and IgM) was seen in the acute phase of the disease. The data suggest that an increased production of IgA1 ICs occurs in IgAN patients; ICs are mainly IgA1-IgG ICs during relapse. The presence of high serum levels of IgG and IgA antibodies against the F(ab')2 region of IgG indicates that in addition to the multiple anomalies of IgA regulation described in IgAN patients there may be further aberrances.
Abstract: The pattern of response to Epstein-Barr virus (EBV) has been investigated in 17 patients with essential mixed cryoglobulinemia (EMC) and in 17 control subjects. All subjects in both groups had IgG to the viral capsid antigen at comparable titers. In the absence of signs of recent infection, 13 patients had IgM to viral capsid antigen and 5 had also IgA, while all the controls were negative. EBV genome was present in bone marrow lymphocytes obtained from 4 patients with type II EMC, but not in those of one patient with type III disease; the latter patient's lymphocytes also failed to produce detectable levels of rheumatoid factor in culture, while the other four patients' lymphocytes released high amounts in culture supernatants. These data support the evidence of an association between type II EMC and persistent EBV infection.
Abstract: To provide further evidence of the nature of intraglomerular immune deposits in essential mixed cryoglobulinemia (EMC), we used two mouse monoclonal antibodies against cross-reactive idiotypes present on monoclonal rheumatoid factors (MoRFs) from patients with type II-EMC. MoAb Cc1 reacted with 9 of 16 circulating IgMk MoRFs tested, and MOAb Lc1 with four of the remaining. Using indirect immunofluorescence and immunoperoxidase techniques, we could identify the same cross-reactive idiotype of the serum MoRF in the renal biopsy specimens from 11 of 13 patients with EMC glomerulonephritis. Kidney specimens from the three patients, whose MoRF was not recognized by MoAbs Cc1 and Lc1, were negative. Two out of 30 control renal biopsies from patients with other forms of glomerulonephritis were shown to contain idiotype (Cc1 and Lc1) positive material. Both patients had serum polyclonal RF which could account for this finding. In conclusion, our results provide direct evidence that serum cryo-MoRF participate in the formation of glomerular immune deposits and, presumably, in the pathogenesis of renal damage in EMC glomerulonephritis.
Abstract: IgA rheumatoid factor, IgA and IgG immune complexes were measured in 119 patients with IgA nephropathy. IgA rheumatoid factor was detected in 62/119 (52%) patients and in 92/265 (35%) serum samples. There was a good correlation (p less than 0.001) between the presence of IgA rheumatoid factor and the presence as well as levels of IgG immune complexes, but not between levels of IgA rheumatoid factor and other clinical or immunological parameters. However, higher levels of serum IgA were found in the subgroup of patients with constantly positive IgA rheumatoid factor. Using aggregated human IgG, we could not demonstrate antiglobulin activity in renal biopsy specimens from 36 patients. These results suggest that IgA rheumatoid factor does not play a primary role in renal damage in IgA nephropathy, but could simply reflect a response to IgG immune complexes in a disorder characterized by abnormalities of IgA production. Nevertheless, the presence of circulating IgA rheumatoid factor in a substantial proportion of patients, especially in those with features of polyclonal IgA activation, provides additional evidence for a general perturbation of IgA metabolism in this disease and could represent an antigen-specific system with which to study regulation of IgA synthesis.
Abstract: To investigate whether patients with IgA nephropathy have an exaggerated serum IgA response to ubiquitous food antigens we measured serum IgA antibodies to gliadin, ovalbumin, bovine serum albumin (BSA), beta-lactoglobulin and casein in 120 patients and 53 normal controls, using ELISA. No significant differences were observed between patients and controls in serum IgA antibodies against each of the antigens tested. Moreover, no correlation was found between serum IgA antibodies and IgA-immune complexes (IgA CIC). However, nine patients but no controls had an association of two or more IgA antibodies to dietary antigens. Sixty-six per cent of these patients (vs 24% in the remaining population) had IgA CIC, suggesting a possible involvement of these antibodies in the constitution of IgA CIC. Analysis of sera by HPLC revealed that both monomeric and higher molecular forms of IgA antibodies were present, the latter being coincident with the peak of IgA CIC. Preincubation of sera with serial concentrations of the specific antigen decreased significantly IgA CIC, suggesting that in this subgroup of patients IgA antibodies to food antigens (mainly BSA) are involved in the formation of IgA CIC. BSA-containing IgA CIC were in fact demonstrated by ELISA using rabbit IgG anti-BSA coated plates and peroxidase-conjugated anti-human IgA. The role of these CIC in the pathogenesis of IgA nephropathy needs to be further elucidated.
Abstract: Primary IgA nephropathy (IgAN) is characterized by the presence of immune complexes (IC), high levels of polymeric IgA (pIgA), and IgA rheumatoid factor (RF) in the blood. The impaired capacity of serum to solubilize IC in the presence of normal values of C hemolytic activity as well as high serum levels of C3, C4, and properdin factor B have led us to analyze whether pIgA and IgA RF from patients with IgAN where capable of inhibiting the capacity of normal human serum to solubilize immune precipitates (BSA-anti-BSA) preformed at equivalence. The results showed a significant reduced mean capacity of serum from patients with IgAN to solubilize "in vitro" immune precipitates (p less than 0.001) and significant high mean levels of pIgA (p less than 0.001) and IgA RF (p less than 0.005) in the blood. Increasing amounts of pIgA inhibited solubilization of IC in the fluid phase, and inhibitory activity was also shown by the IgA RF. There were inverse correlations between pIgA and the capacity of serum to solubilize IC (r = -0.36; p less than 0.05), and between IgA RF and the complement-mediated solubilization (r = -0.57; p less than 0.001). It is suggested that pIgA and IgA RF may be responsible for the impaired complement-mediated solubilization of serum and the persistence of insoluble nephritogenic IC in the blood of patients with primary IgAN.
Abstract: Circulating IgA-antigliadin antibodies were detected with enzyme linked immunosorbent assay (ELISA) in four of 121 patients (3%) who had IgA mesangial nephropathy and 14 of 17 children (82%) who had untreated coeliac disease. No positive cases were present in the 54 healthy subjects of the control group. Three patients who had IgA nephropathy and IgA-antigliadin antibodies underwent jejunal biopsy, and two showed mucosal atrophy. In these two patients urinary abnormalities, together with the IgA-antigliadin antibodies, disappeared completely after three months and five months, respectively, of following a gluten free diet. Circulating IgA immune complexes were found in most patients who had coeliac disease and Berger's disease associated with IgA-antigliadin antibodies, suggesting overactivity of the B cells producing IgA in both conditions. By contrast, a circulating IgA rheumatoid factor was detectable in three of the four patients who had IgA nephropathy and asymptomatic coeliac disease but was always absent in children who had coeliac disease but did not show signs of renal disease. These results suggest that a more complex abnormality in the IgA immune response is necessary for renal disease to become manifest in patients who have gluten enteropathy.
Abstract: In order to evaluate functional lymphocyte defects in type II essential mixed cryoglobulinaemia (EMC) in vitro production of immunoglobulins (Ig) and rheumatoid factor (RF) has been studied in basal conditions and under pokeweed mitogen (PWM) stimulation in 15 patients and in 17 control subjects. The major finding was a significantly high basal and inducible production of RF by EMC lymphocytes as compared with the RF production in controls, while synthesis of polyclonal Ig was unaffected. A good correlation existed between in vitro production and serum levels of RF. Peripheral blood SmIg+ and Ia+ cells were also significantly increased. The possibility that EMC shares some pathogenetic mechanism with rheumatoid arthritis on the one hand and with lymphoproliferative diseases on the other is considered.
Abstract: A specific and sensitive enzyme-linked immunosorbent assay (ELISA) was used to detect IgA rheumatoid factor (RF) in sera from 88 patients with IgA nephropathy (IgA GN), a disease characterized by abnormalities of IgA production. Significantly higher levels of IgA antiglobulins were demonstrated in IgA GN patients than in normal healthy controls and patients with other forms of chronic primary glomerulonephritis (mean +/- SEM 28.4 +/- 6.6 vs 6.0 +/- 0.4 and 8.3 +/- 1.2 micrograms/ml respectively; p less than 0.002). Interestingly, in contrast to rheumatoid arthritis, IgA RF activity was not associated with IgM antiglobulins. Analysis of sera fractionated by gel chromatography at acid pH revealed that anti-IgG activity resided predominantly in the polymeric fractions of IgA as confirmed by the ability to bind "free" secretory component. Several findings in patients with IgA GN suggest that the IgA deposited in the glomeruli is polymeric, and levels of circulating macromolecular IgA are increased. Our findings confirm a general perturbation of IgA metabolism in this disease. Although the polymeric nature of the IgA RF is suggestive of a mucosal origin, additional evidence is needed to confirm this hypothesis.
Abstract: Antibodies to ubiquitous Herpes viruses have been studied in 13 patients with type II essential mixed cryoglobulinemia (EMC), and in two different control groups. All the EMC patients had monoclonal IgM kappa in their cryoprecipitates. IgM antibodies to the viral capsid antigen (VCA) of Epstein-Barr virus (EBV) were found in the sera of 11 EMC patients but all the cryoprecipitates were negative. IgG antibodies were also present in the sera of all and in the cryoprecipitates of some patients. In contrast, the number of subjects with antibodies to Cytomegalovirus (CMV) and Hepatitis B Virus (HBV) was not higher than in controls. Possible correlations between EMC and EBV infection are discussed.
Abstract: Peripheral blood mononuclear cells (PBMC) from patients with Essential Mixed Cryoglobulinemia (EMC) were studied for their ability to synthesize polyclonal IgM and rheumatoid factor (RF) IgM in vitro. Our results indicate: that EMC-PBMC produce smaller amounts of polyclonal IgM but higher quantities of IgM-RF than normal PBMC after pokeweed mitogen (PWM) or Staphylococcus aureus activation, so that the IgM-RF to total IgM ratio is significantly greater in EMC than in normal cultures; that enriched EMC-B lymphocytes display a significantly higher spontaneous synthesis of IgM-RF than normal B lymphocytes and that the IgM-RF B cell clones are receptive to T cell regulation. Taken together these findings suggest an expansion of B cell clones committed to IgM RF production and the presence in peripheral blood of differentiated B lymphocytes capable of secreting IgM-RF in EMC.
Abstract: Plasma exchange is increasingly used for management of Essential Mixed Cryoglobulinemia. However little is known about the long term effects of this treatment. Therefore we have reviewed the clinical and laboratory data of 20 patients with type II EMC who were followed for a mean of 24 months. 16 patients had renal involvement, which was characterized histologically in all of them: 9 had diffuse proliferative GN plus endoluminal "thrombi" in 6 and vasculitis in 5, 4 had lobular membranoproliferative GN and 3 had focal proliferative GN. 14 patients had renal failure and 13 had proteinuria greater than or equal to 2 g/24 hr. PE (combined with immunosuppressive drugs in 18) was performed for a mean of 18 procedures. The combined treatment induced prompt remission of extrarenal and renal involvement. Serum creatinine and proteinuria decreased significantly in all but 2 patients during the treatment (s. creatinine from 2.9 to 1.6 mg/dl; proteinuria from 3.5 to 1.6 g/24 hr). Analysis of long term follow up revealed that these effects were long lasting in all the cases. We conclude that PE should be used for EMC nephropathy whenever prompt remission is not obtained by conventional therapy especially in consideration of its long term beneficial effects.
Abstract: T-lymphocyte subsets, using the monoclonal antibodies OKT3 (peripheral T-cells), OKT4 (helper/inducer T-cells) and OKT8 (suppressor/cytotoxic T-cells) were measured in peripheral blood from 110 patients with various forms of primary and secondary glomerulonephritis (GN) (Berger's disease, membranous GN, focal glomerulosclerosis, membranoproliferative GN, lupus nephritis and mixed essential cryoglobulinaemia with GN). We have found a significantly higher OKT4+/OKT8+ ratio in patients with Berger's disease and membranous GN and a rather low OKT4+/OKT8+ ratio in patients with lupus nephritis and mixed essential cryoglobulinaemia, due to a significant decrease in OKT4+ cells. Our results suggest an imbalance in immunoregulatory mechanisms in some forms of GN.
Abstract: Intensive plasma exchange and immunosuppression have been used in 13 patients affected by severe forms of glomerulonephritis (GN) associated with systemic lupus erythematosus (SLE) and essential mixed cryoglobulinaemia (EMC). The patients were divided into two groups.
Abstract: Ten adult patients with RPCGN (crescents in greater than 70% of glomeruli), primary in 6 and associated with systemic diseases in 4, were treated with PE, associated with oral steroids (P) and cyclophosphamide (C) in all cases and with intravenous methylprednisolone pulses (MP) in 7 cases. Four out of ten patients were anuric and needed dialysis treatment at the start of treatment. Therapeutic benefit, i.e. reversal of the trend to further deterioration and substantial improvement of GFR, was achieved in 8 out of 10 patients (80%), including 2 of 4 anuric patients, and in 7 of those (8) who had still active cellular crescents (87.5%). Similar therapeutic benefit had been achieved only in 10% of a comparable population of 10 patients with RPCGN treated before 1980 with P and C, without PE or MP pulses. It is difficult to establish whether the better therapeutic results in the more recently treated group were due to PE or to MP pulses of to both the new approaches, even though the clinical improvement obtained in all the 3 patients treated with PE without concomitant MP suggest a specific beneficial role for PE. RPCGN is a catastrophic illness characterized by progressive deterioration of kidney function, resulting in oliguria and uremia, usually within weeks or months. The most consistent histopathologic finding is the presence of extensive glomerular crescents resulting from proliferation of the extracapillary epithelial cell lining of Bowman's capsule. It is apparent that RPCGN is not a homogeneous entity, clinically, histologically or immunohistologically, but rather a clinicopathologic syndrome, the features of which may be seen in a variety of systemic disorders, including SLE, polyarteritis nodosa, Wegener's granulomatosis, Henoch-Schönlein purpura, cryoglobulinemia, and subacute bacterial endocarditis.(ABSTRACT TRUNCATED AT 250 WORDS)
