title: Immune complexes in progressive systemic sclerosis and mixed connective tissue disease.
abstract: Sera from patients with progressive systemic sclerosis (PSS) and mixed connective tissue disease (MCTD) were studied for the presence of circulating immune complexes (CICs) by Clq precipitins, cryoglobulins and the Raji cell and Clq radioimmunoassays. The Raji cell assay was the most sensitive, detecting ICs in 82% of patients with MCTD and in 55% with PSS. However, the median value in MCTD was significantly higher than in PSS (79 vs 20 microgram equivalent AHG/ml serum), and in MCTD, unlike PSS, the CIC levels appeared to parallel disease activity. Ribonucleoprotein (RNP) antigen could not be demonstrated in the Raji cell bound complexes.
mesh_terms: D000328:Adult; D000368:Aged; D000936:Antigen-Antibody Complex; D001665:Binding Sites; D002460:Cell Line; D003172:Complement C1; D003165:Complement System Proteins; D003450:Cryoglobulins; D005260:Female; D006801:Humans; D007668:Kidney / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D008947:Mixed Connective Tissue Disease / Q000150:complications / Q000276:immunology*; D011507:Proteinuria / Q000150:complications; D006435:Renal Dialysis; D012595:Scleroderma, Systemic / Q000276:immunology*
chemical_list: D000936:Antigen-Antibody Complex; D003172:Complement C1; D003450:Cryoglobulins; D003165:Complement System Proteins