Serum immunoglobulin sedimentation patterns and circulating immune complexes in IgA glomerulonephritis and Schönlein-Henoch nephritis.
Sera from 8 patients with IgA glomerulonephritis and from 6 patients with Schönlein-Henoch nephritis were investigated by the C1q-binding assay (C1q-BA) test and by sucrose gradient centrifugation followed by sensitive solid phase radioimmunoassay determinations of IgA, IgG and IgM in each fraction obtained. Abnormal sedimentation profiles were found in sera from 3 of 8 patients with IgA nephritis and in 3 of 6 patients with Schönlein-Henoch nephritis. The abnormal fraction consisted of low molecular weight IgA in 2 patients, IgG in 1 patient and IgM in 4 patients. The absolute level of polymeric IgA was increased in 3 of 8 patients with IgA nephritis, but the relative distribution was normal. An abnormal sedimentation pattern of immunoglobulins was correlated to a positive C1q-BA test (p less than 0.001).
D000293:Adolescent; D000328:Adult; D000936:Antigen-Antibody Complex / Q000032:analysis*; D002499:Centrifugation, Density Gradient; D002648:Child; D003167:Complement Activation; D003172:Complement C1; D005260:Female; D005921:Glomerulonephritis / Q000276:immunology*; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis*; D007074:Immunoglobulin G / Q000032:analysis*; D007075:Immunoglobulin M / Q000032:analysis*; D007158:Immunologic Techniques; D008180:Lupus Erythematosus, Systemic / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009393:Nephritis / Q000276:immunology*; D011863:Radioimmunoassay; D013577:Syndrome
D000936:Antigen-Antibody Complex; D003172:Complement C1; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M