Home About us Contact | |||
ANCA-associated Vasculitis (ANCA-associat + vasculitis)
Selected AbstractsSystemic granulomatous necrotizing vasculitis in a MPO,ANCA-positive patientPATHOLOGY INTERNATIONAL, Issue 8 2004Atsushi Kurata We present a case of myeloperoxidase antineutrophil cytoplasmic antibody (MPO,ANCA)-associated vasculitis that demonstrated a systemic granulomatous lesion at autopsy. The patient initially showed anorexia, general malaise and anemia. Colon fiber was examined to detect the bleeding site, which revealed ischemic mucosal damage associated with venous fibrin thrombus. Because a high titer of MPO,ANCA was found, ANCA-associated vasculitis was suspected and the patient was started on steroid pulse therapy. However, anemia, renal failure and respiratory failure worsened and the patient died of sudden cardiac failure 2 days after the start of the therapy. An autopsy revealed systemic arteritis in multiple organs including the kidneys, liver, spleen, gastrointestinal system and genital organs that indicated fibrinoid necrosis accompanied by granulomatous reaction with multinucleated giant cells; the granulomatous reaction further extended along the splenic capsule. Glomerulonephritis and diffuse pulmonary damage, which are common in MPO,ANCA-associated vasculitis, were almost absent but parapleural fibrosis was present. The direct cause of death was presumed to be hemorrhagic shock due to rupture of an aneurysm in the gastric subserosa. As far as we know, this is the first case of a systemic granulomatous reaction in MPO,ANCA-positive vasculitis, although the cause of the granulomatous lesion is unknown. [source] Treatment of ANCA-associated systemic small-vessel vasculitisAPMIS, Issue 2009DAVID JAYNE Much has been learnt over the last 30 years to optimize the use of immunosuppressive and glucocorticoid therapies that has allowed the publication of treatment guidelines. However, major unmet needs remain in the treatment of ANCA-associated vasculitis (AAV) and include refractory disease, only partial efficacy and toxicity of current drugs and the need for long-term regimens. Newer therapies, including mycophenolate mofetil, leflunomide and rituximab, are providing a real opportunity for improved outcomes of AAV in the future. The development of therapy has been facilitated by international clinical research networks but delayed by the complexities of studying an uncommon, multi-system disease. [source] Neutrophils and B lymphocytes in ANCA-associated vasculitisAPMIS, Issue 2009VÉRONIQUE WITKO-SARSAT The pathogenesis of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is unknown but is most consistent with a primary role for neutrophils in the acute injury. Thus, neutrophils are cardinal cells in the pathophysiological process in AAV because they are both effector cells responsible for endothelial damage and targets of autoimmunity. In addition, because of their capacity to synthesize a wide variety of cytokines and chemokines, neutrophils can be considered as important modulators of the inflammatory and potentially of the autoimmune process. ANCA directed against two main autoantigens, namely proteinase 3 and myeloperoxidase, are likely to play a modulatory role in the inflammatory process. Interestingly, neutrophils are an important source of lymphocyte stimulator (BLy), a cytokine that plays a fundamental role in B-cell physiology, including differentiation, proliferation and immunoglobulin production. The issue of B-cell activation and/or dysregulation in vasculitis will be discussed. [source] A multicenter survey of rituximab therapy for refractory antineutrophil cytoplasmic antibody,associated vasculitisARTHRITIS & RHEUMATISM, Issue 7 2009Rachel B. Jones Objective B cell depletion with rituximab has allowed remissions in relapsing or refractory antineutrophil cytoplasmic antibody (ANCA),associated vasculitis in small studies. The aim of this study was to determine the efficacy and safety of rituximab for ANCA-associated vasculitis in a larger multicenter cohort. This permitted comparison of rituximab dosing regimens, the value of continuing immunosuppression, and investigation of ANCA and B cell levels as re-treatment biomarkers. Methods Retrospective, standardized data collection from 65 sequential patients receiving rituximab for refractory ANCA-associated vasculitis at 4 centers in the UK was used. Results All patients achieved B cell depletion. Complete remission occurred in 49 of the 65 patients (75%), partial remission in 15 (23%), and no response in 1 (2%). The prednisolone dosage was reduced from 12.5 mg/day (median) to 9.0 mg/day at 6 months (P = 0.0006). Immunosuppressive therapy was withdrawn in 37 of 60 patients (62%). Twenty-eight of 49 patients who achieved full remission (57%) experienced relapse (median 11.5 months). B cell return preceded relapse in 14 of 27 patients (52%). Although ANCA levels fell after rituximab therapy, relapse was not associated with ANCA positivity or a rise in ANCA levels. Neither the initial rituximab regimen (4 infusions of 375 mg/m2 each given 1 week apart or 2 infusions of 1 gm each given 2 weeks apart) nor withdrawal of immunosuppressive therapy (37 of 60 patients [62%]) influenced the timing of relapse. Thirty-eight patients received ,2 courses of rituximab, and complete remission was induced or maintained in 32 of them (84%). IgM levels fell, although IgG levels remained stable. Forty-six serious adverse events occurred, including 2 episodes of late-onset neutropenia, which were attributed to rituximab. Conclusion Rituximab was effective remission induction therapy for refractory ANCA-associated vasculitis in this study. There was no difference in efficacy between the 2 main treatment regimens. Continuing immunosuppression did not reduce relapses. Relapses occurred, but re-treatment was effective and safe. There was no clear influence of rituximab on the frequency of serious adverse events. ANCA and B cell levels lacked sufficient sensitivity to guide the timing of re-treatment. [source] B cell epitope specificity in ANCA-associated vasculitis: does it matter?CLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2004Y. M. VAN DER GELD SUMMARY Pauci-immune idiopathic small-vessel vasculitis is strongly associated with the presence of antineutrophil cytoplasm autoantibodies (ANCA). Antibodies to PR3 predominate in patients with Wegener's granulomatosis; antibodies to myeloperoxidase (MPO) are found more frequently in patients with microscopic polyangiitis. There is increasing in vivo and in vitro evidence for a pathogenic role of ANCA in systemic vasculitis based on associations of ANCA with disease activity. If ANCA are pathogenic, why is the course of disease different from one patient to another? Antibodies can recognize different binding sites (epitopes) on their corresponding antigens. Differences in binding specificity may influence the pathogenic potential of the antibodies. Differences between epitope specificity of ANCA between patients or changes in epitope specificity of ANCA in time in an individual patient may, accordingly, result in differences in disease expression. This review will focus on epitope specificity of autoantibodies in systemic autoimmune diseases and especially on the epitope specificity of PR3, and MPO,ANCA. We will discuss whether PR3,ANCA or MPO,ANCA recognize different epitopes on PR3 and MPO, respectively, and whether the epitopes recognized by ANCA change in parallel with the disease activity of ANCA-associated vasculitis. Finally, we will speculate if the direct pathogenic role of ANCA can be ascribed to one relapse- or disease-inducing epitope. Characterization of relapse- or disease-inducing epitopes bound by PR3,ANCA and MPO,ANCA is significant for understanding initiation and reactivation of ANCA-associated vasculitis. Elucidating a disease-inducing epitope bound by ANCA may lead to the development of epitope-specific therapeutic strategies. [source] |