title: Circulating Fc-receptor blocking factors in IgA nephropathies.
abstract: Twenty-one patients with primary IgA nephropathy, 7 patients with Henoch-Schönlein nephritis and 4 patients with IgA nephropathy associated to alcoholic liver cirrhosis were tested for Fc-receptor phagocyte function by measuring the clearance of radiolabelled IgG-sensitized erythrocytes in vivo and the immune phagocytosis by monocytes in vitro. Meanwhile IgG-, IgA-, IgA1-, IgA2-, containing immune complexes, the complement components C3, C4, C3d and the HLA-A, B, DR phenotype were determined. The patients with major urinary abnormalities were well discriminated from those with only minimal hematuria by a defective macrophage function (p less than 0.01) and high levels of IgA immune complexes (p less than 0.02). Since non HLA-A, B, C, DR phenotype was prevalent in patients who had defective Fc-receptor function, whereas a significant correlation was found between Fc-receptor impairment and levels of IgA immune complexes, it appears likely that circulating blocking factors, possibly related to IgA containing immune materials, may impair macrophage function in IgA nephropathies.
mesh_terms: D000293:Adolescent; D000328:Adult; D000936:Antigen-Antibody Complex / Q000276:immunology; D015703:Antigens, CD; D002648:Child; D003176:Complement C3 / Q000032:analysis; D015933:Complement C3d; D003181:Complement C4 / Q000032:analysis; D004912:Erythrocytes / Q000276:immunology; D005260:Female; D005922:Glomerulonephritis, IGA / Q000276:immunology*; D006650:Histocompatibility Testing; D006801:Humans; D008264:Macrophages / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000276:immunology; D009393:Nephritis / Q000276:immunology; D010587:Phagocytosis; D011961:Receptors, Fc / Q000276:immunology*; D012397:Rosette Formation
chemical_list: D000936:Antigen-Antibody Complex; D015703:Antigens, CD; D003176:Complement C3; D003181:Complement C4; C036832:Fc(alpha) receptor; D011961:Receptors, Fc; D015933:Complement C3d