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IgA Deposition (iga + deposition)
Kinds of IgA Deposition Selected AbstractsIncreased sialylation of polymeric ,-IgA1 in patients with IgA nephropathyJOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 1 2002Joseph C.K. Leung Abstract The mechanism of mesangial IgA deposition is poorly understood in IgA nephropathy (IgAN). Abnormal glycosylation of carbohydrate moieties in the hinge region of the IgA molecule has recently attracted much attention. In this report, we studied galactosylation and sialylation profiles in ,- and ,-IgA1 from patients with IgAN. Total serum IgA1 was isolated from patients with IgAN or healthy controls by jacalin-affinity chromatography. Six fractions of molecular weight (MW) 50,1,000 kDa were separated by fast protein liquid chromatography (FPLC). Four lectin-binding assays were used to study the sialylation and the presence of terminal galactose or N-acetylgalactosamine (GalNAc) in the O-linked carbohydrate moieties of ,- or ,-IgA1. Maackia amurensis agglutinin (MAA) and Sambucus nigra agglutinin (SNA) lectin recognize ,(2,3)- and ,(2,6)-linked sialic acid, respectively. Peanut agglutinin (PNA) and Helix aspersa (HA) lectin recognize terminal galactose and GalNAc, respectively. Reduced HA was demonstrated in macromolecular , or ,-IgA1 (300,825 kDa) isolated from patients with IgAN (P < 0.05 compared with healthy controls). Lambda- but not ,-IgA1 from patients with IgAN bound less to PNA (P < 0.05). The ,(2,3)-linked sialic acid content in ,- but not ,-IgA1 of MW 150,610 kDa from patients was higher than that of controls (P < 0.005). The ,(2,6)-linked sialic acid content in ,-IgA1 (300,825 kDa) and ,-IgA1 (150,610 kDa) from patients was also higher than that of controls. This unusual glycosylation and sialylation pattern of the ,-IgA1 may have important implications for the pathogenesis of IgAN, as both the masking effect of sialic acid on galactose and the reduced galactosylation will hinder the clearance of macromolecular ,-IgA1 by asialoglycoprotein receptor of hepatocytes. The negative charge from sialic acid may also favor mesangial deposition of macromolecular ,-IgA1 in IgAN. J. Clin. Lab. Anal. 16:11,19, 2002. © 2002 Wiley-Liss, Inc. [source] Fibrillar IgA deposition in dermatitis herpetiformis , an underreported pattern with potential clinical significanceJOURNAL OF CUTANEOUS PATHOLOGY, Issue 4 2010Christine J. Ko Dermatitis herpetiformis has characteristic clinical and histopathologic findings. A fibrillar pattern of IgA deposition on direct immunofluorescence in dermatitis herpetiformis is underreported. Here, we describe three patients with the fibrillar pattern of IgA deposition on direct immunofluorescence examination that initially misled diagnosis in one of the three. Interestingly, two of the three patients lacked anti-transglutaminase and anti-endomysial antibodies but had a clinical course typical of dermatitis herpetiformis. Dermatitis herpetiformis may have a fibrillar rather than granular pattern of IgA deposition on direct immunofluorescent microscopy, and patients with this pattern of immunoglobulin deposition may lack circulating autoantibodies. Ko CJ, Colegio OR, Moss JE, McNiff JM. Fibrillar IgA deposition in dermatitis herpetiformis,an underreported pattern with potential clinical significance. [source] The spectrum of cutaneous lesions in rheumatoid arthritis: a clinical and pathological study of 43 patientsJOURNAL OF CUTANEOUS PATHOLOGY, Issue 1 2003C. M. Magro Introduction:, Rheumatoid arthritis (RA) is an idiopathic arthropathy syndrome that has a propensity to affect the small joints of the hands and feet with extra-articular manifestations comprising skin lesions, neuropathy, pericarditis, pleuritis, interstitial pulmonary fibrosis and a systemic polyarteritis nodosa (PAN)-like vasculitic syndrome. The most widely recognized skin lesion is the rheumatoid nodule. Other skin manifestations are poorly defined. Materials and methods:, Using a natural language search of the authors' outpatient dermatopathology databases, skin biopsies from 43 patients with RA were selected for retrospective analysis in an attempt to define the dermatopathological spectrum of RA and its clinical correlates. Results:, The biopsies were categorized by the dominant histologic pattern, recognizing that in most cases there were additional minor reaction patterns. Palisading and/or diffuse interstitial granulomatous inflammation was the dominant pattern seen in 21 patients; the lesions included nodules, plaques and papules with a predilection to involve skin over joints. Besides interstitial histiocytic infiltrates and variable collagen necrobiosis, these cases also showed interstitial neutrophilia, vasculitis and pauci-inflammatory vascular thrombosis. The dominant morphology in 11 other patients was vasculopathic in nature: pauci-inflammatory vascular thrombosis, glomeruloid neovascularization, a neutrophilic vasculitis of pustular, folliculocentric, leukocytoclastic or benign cutaneous PAN types, granulomatous vasculitis, and lymphocytic vasculitis and finally occlusive intravascular histiocytic foci for which the designation of ,RA-associated intravascular histiocytopathy' is proposed. Rheumatoid factor (RF) positivity and active arthritis were common in this group, with anti-Ro and anticardiolipin antibodies being co-factors contributing to vascular injury in some cases. Immunofluorescent testing in three patients revealed dominant vascular IgA deposition. In nine patients, the main pattern was one of neutrophilic dermal and/or subcuticular infiltrates manifested clinically as urticarial plaques, pyoderma gangrenosum and panniculitis. Conclusions:, The cutaneous manifestations of RA are varied and encompass a number of entities, some of which define the dominant clinical features, such as the rheumatoid papule or subcutaneous cords, while others allude to the histopathology, i.e. rheumatoid neutrophilic dermatosis. We propose a more simplified classification scheme using the adjectival modifiers of ,rheumatoid-associated' and then further categorizing the lesion according to the dominant reaction pattern. Three principal reaction patterns are recognized, namely extravascular palisading granulomatous inflammation, interstitial and/or subcuticular neutrophilia and active vasculopathy encompassing lymphocyte-dominant, neutrophil-rich and granulomatous vasculitis. In most cases, an overlap of the three reaction patterns is seen. Co-factors for the vascular injury that we believe are integral to the skin lesions of RA include RF, anti-endothelial antibodies of IgA class, anti-Ro and anticardiolipin antibodies. [source] Continuous administration of human desialo-degalacto IgA1 causes mesangial IgA deposition in KM mouse having entire human Ig lociNEPHROLOGY, Issue 2005YOSHIYUKI HIKI [source] Role of mucosal immunity dependent on GATA-3 in glomerular IgA depositionNEPHROLOGY, Issue 2005TAKAHIRO YAMANAKA [source] Effect of soluble form CTLA-4 on spontaneous IgA nephropathy in ddY miceNEPHROLOGY, Issue 2001K Okano The aim of the present study was to examine the role of CD28-B7 signalling in the development of glomerulonephritis in ddY mice, an animal model for IgA nephropathy. To achieve this aim, we investigated whether the CTLA-4 (CD152) fusion protein, which binds to B7.1 (CD80) and B7.2 (CD86), affects glomerular pathological changes (including IgA deposition), or functional parameters (such as serum creatinine and proteinuria). Each group (n = 4) was given either human CTLA-4 fused with human IgG (CTLA4Ig) or control human IgG1. All treated groups of mice were injected intraperitoneally at a dose of 0.1 mg twice a week for the duration of the study. Mice given control human IgG1 progressively developed typical mesangioproliferative glomerulonephritis, with remarkable glomerular IgA deposits. In contrast, mice treated with CTLA4Ig showed a significant reduction in proteinuria and mesangioproliferative change, with an expansion of the mesangial matrix at 40 weeks of age. The serum IgA levels of these mice were considerably lower than those in mice given the control human IgG1. A direct immunofluorescence study showed the reduction of glomerular IgA deposits in CTLA4Ig-treated mice. We have demonstrated for the first time that the development of spontaneously occurring IgA nephropathy can be prevented in ddY mice by blocking the CD28-B7 interaction using a soluble form of CTLA4Ig. These results suggest that a costimulatory signal via CD28-B7 may play a crucial role in the development and progression of IgA nephropathy. [source] Significance of incidental mesangial IgA deposition in minimal change nephrotic syndromeNEPHROLOGY, Issue 2001M Tsukada Background: Incidental IgA deposition in glomerular mesangium exists in 10,20% of autopsy kidneys1,2 or renal allograft donors.3 In the present study, we examined the clinicopathological features of incidental mesangial IgA deposition in renal biopsy from patients with minimal change nephrotic syndrome (MCNS) to understand the significance of mesangial IgA deposition in MCNS and pathogenesis of IgA nephropathy. Patients and Methods: From January 1994 to September 2000, 63 patients were diagnosed with MCNS by renal biopsy at Kidney Center, Tokyo Women's Medical University. Mesangial IgA and C3 deposition was examined by immunofluorescence staining using frozen sections. The frequency of IgA and C3 deposition in MCNS and clinicopathological features of IgA-positive patients with MCNS were investigated. Results: The mesangial IgA deposition was present in 15 out of 63 patients (23.8%). Among these 15 patients, codeposition of C3 was present in 10 patients (66.7%) (Fig. 1). The serum IgA concentration was significantly higher in the IgA-positive patients than in the IgA-negative patients (309 ± 75 mg/dL versus 245 ± 106 mg/dL, P = 0.043) (Fig. 2). The urinary red blood cell count was higher in IgA-positive patients than in IgA-negative patients, although not significantly different (11.7 ± 12.7 counts/HPF versus 5.3 ± 4.0 counts/HPF, P = 0.067) (Fig. 3). Other clinical parameters (age, sex, amount of proteinuria, serum creatinine and creatinine clearance) were not significantly different. Histologically, no significant differences were observed between IgA-positive and IgA-negative patients in following parameters: grade of mesangial cell proliferation and mesangial matrix increase, extents of tubular atrophy and interstitial fibrosis and grade of vascular sclerosis. After steroid treatment, all 15 patients with mesangial IgA deposition had become complete remission, although three patients once relapsed proteinuria. The haematuria also disappeared after steroid treatment in these patients. Figure 1. The frequency of mesangial IgA and C3 deposition in MCNS patients (n = 63). The mesangial IgA deposition was present in 15 out of 63 patients (23.8%). Among these 15 patients, codeposition of C3 was present in 10 patients (66.7%). Figure 2. The serum IgA concentration of the MCNS patients with and without mesangial IgA deposition. The serum IgA concentration was significantly higher in IgA-positive patients (n = 15) than in IgA-negative patients (n = 48) (309 ± 75 mg/dL vs 245 ± 106 mg/dL, P = 0.043). Figure 3. The urinary red blood cell counts of the MCNS patients with and without mesangial IgA deposition. The urinary red blood cell count was higher in IgA-positive patients (n = 15) than in IgA-negative patients (n = 48), although not significantly different (11.7 ± 12.7 counts/HPF vs 5.3 ± 4.0 counts/HPF, P = 0.067). Conclusion: The incidental mesangial IgA deposition was frequently observed in MCNS patients (15/60 patients, 23.8%). The phenomenon of mesangial IgA deposition in MCNS patients was related to higher serum IgA concentration and might cause slight haematuria. However, no influence of mesangial IgA deposition was found on the renal function and the clinical outcome of MCNS after treatment. [source] Polyangitis overlap syndrome: A fatal case combined with adult Henoch-Schönlein purpura and polyarteritis nodosaPATHOLOGY INTERNATIONAL, Issue 8 2003Kazuo Watanabe Henoch-Schönlein purpura (HSP) is a rather common disease characterized by systemic hypersensitivity vasculitis in the skin and other visceral organs. It has a favorable prognosis unless it is complicated by severe glomerular disease. We report a distinctive fatal case of systemic vasculitis combined with HSP and polyarteritis nodosa (PN) in a 56-year-old man who died of progressive renal failure one month after the onset of the disease. He complained of arthralgia, purpura of both lower extremities, nasal bleeding and tarry stool, and acute renal failure was noted at the time of admission to hospital. A skin biopsy from the purpura lesion exhibited leucocytoclastic vasculitis with IgA deposition, and HSP was considered. However, renal failure progressed rapidly and subsequently was complicated by acute myocardial infarction. Postmortem examination revealed PN type necrotizing vasculitis in the kidneys, heart and mesentery resulting in acute multiple infarctions of these organs. We think the current case was a polyangitis overlap syndrome. It is important to suspect the polyangitis overlap syndrome positively when progressive acute renal failure is seen in a patient with HSP and to begin appropriate therapy immediately. [source] | ||||||||||