Immune complexes in progressive systemic sclerosis and mixed connective tissue disease
Cunningham, P.H.; Andrews, B.S.; Davis, J.S.
Journal of Rheumatology 7(3): 301-308
1980
ISSN/ISBN: 0315-162X PMID: 7401065 Document Number: 166030
Sera from patients with progressive systemic sclerosis (PSS) and mixed connective tissue disease (MCTD) were studied for the presence of circulating immune complexes (CIC) by Clq cell and Clq radioimmunoassays. The Raji cell assay was the most sensitive, detecting CIC in 82% of patients with MCTD and in 55% with PSS. The median value in MCTD was significantly higher than in PSS (79 vs. 20 .mu.g equivalent AHG/ml serum); in MCTD, unlike PSS, the CIC level appeared to parallel disease activity. Ribonucleoprotein antigen could not be demonstrated in the Raji cell bound complexes.