Immunohistochemical analysis of C3 cleavage fragments, factor H, and the C5b-9 terminal complex of complement in de novo membranous glomerulonephritis occurring in patients with renal transplant.
Fifteen renal biopsies from 13 transplanted patients with de novo membranous nephropathy (DNMN) were investigated by immunofluorescence for the presence of C5b-9 neoantigens of the terminal sequence of complement and for antigens expressed by C3 cleavage fragments. DNMN lesions were classified as stage I, II or III upon light and electron microscopy examination. Seven biopsies were classified as stage I DNMN and 8 stage II-III. All patients were proteinuric. In six biopsies with stage I DNMN, staining for C5b-9 neoantigens was restricted to a fine granular labeling in mesangial areas which was analogous to that seen in normal kidneys in contrast with extensive parietal labeling for IgG, C3d and factor H antigens. In eight biopsies with stage II-III DNMN, the pattern of staining with anti-C5b-9 neoantigens antibodies was similar to that obtained with anti-IgG, anti-C3d and anti-factor H antibodies. These results suggest that in situ activation of the whole complement sequence throughout C5b-9 only occurs on large immune deposits (stage II-III DNMN).
D000293:Adolescent; D000328:Adult; D002648:Child; D003167:Complement Activation; D003176:Complement C3 / Q000032:analysis; D003180:Complement C3b Inactivator Proteins / Q000032:analysis; D015933:Complement C3d; D017242:Complement Factor H; D015938:Complement Membrane Attack Complex; D003165:Complement System Proteins / Q000032:analysis; D005260:Female; D005455:Fluorescent Antibody Technique; D005921:Glomerulonephritis / Q000209:etiology / Q000276:immunology* / Q000473:pathology; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D007668:Kidney / Q000473:pathology; D016030:Kidney Transplantation; D008297:Male; D011183:Postoperative Complications
C493495:CFH protein, human; D003176:Complement C3; D003180:Complement C3b Inactivator Proteins; D015938:Complement Membrane Attack Complex; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D015933:Complement C3d; D017242:Complement Factor H; D003165:Complement System Proteins