Platelet-aggregating immune complexes and intraplatelet serotonin in idiopathic glomerulonephritis and systemic lupus.
Immune complex-like material was studied using the platelet-aggregation test (PAT) in 114 patients with idiopathic glomerulonephritis and 55 patients with SLE nephritis, and the results obtained compared with Raji cell and Clq-binding assays. The platelet-aggregating material was not thrombin, and eluted from Sepharose CL/6B columns with a molecular weight of greater than 500,000 daltons. Sera from 17 of 55 patients with SLE nephritis were positive in all three assays, 50/55 in at least one assay. No circulating material was detected by the Raji cell assay in idiopathic glomerulonephritis patients, but both the Clq-binding and PAT assays detected material in patients with acute post-infectious nephritis and mesangiocapillary glomerulonephritis. Patients with membranous nephropathy and Henoch-Schönlein purpura were positive in the PAT, although generally negative in the other assays of immune complexes. The amount of platelet-aggregating material (PAM) found in the sera of patients with both idiopathic glomerulonephritis and SLE nephritis correlated closely with the depletion of intraplatelet serotonin, suggesting that this material is a major mechanism of in vivo platelet activation in these patients.
D000936:Antigen-Antibody Complex / Q000032:analysis*; D001792:Blood Platelets / Q000378:metabolism*; D002648:Child; D002850:Chromatography, Gel; D005921:Glomerulonephritis / Q000097:blood / Q000276:immunology*; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000276:immunology*; D010974:Platelet Aggregation; D012701:Serotonin / Q000097:blood*
D000936:Antigen-Antibody Complex; D012701:Serotonin