Metabolism of c4 and factor b in rheumatoid arthritis

✍ Scribed by Roy A. Kaplan; John G. Curd; David H. Deheer; Dennis A. Carson; Michael K. Pangburn; HANS J. Müller-E Berhard; John H. Vaughan

• Publisher: John Wiley and Sons
• Year: 1980
• Tongue: English
• Weight: 829 KB
• Volume: 23
• Category: Article
• ISSN: 0004-3591
• DOI: 10.1002/art.1780230806

✦ Synopsis

Abstract

Metabolic turnover determined by radioiodide labeled C4 and Factor B was studied in 18 patients with rheumatoid arthritis (RA) and 19 normal control subjects as a means of estimating the relative ratio of consumption of components in the classical and alternative pathways of complement activation. Predominance of fractional catabolic rate (FCR) of C4 over Factor B was demonstrated with differentially labeled C4 and Factor B. The hypercatabolism occurred in the extravascular space. C4 FCR correlated significantly with rheumatoid factor (RF) determined in a hemolytic assay (r~s~ = 0.72), measured as IgG RF (r~s~ = 0.57), and as IgM RF (r~s~ = 0.45). There were no significant correlations with several other antibodies measured. These results are consistent with the hypothesis that RA is a systemic, extravascular immune complex disease, in which RF immune complexes play a significant pathogenetic role principally via activation of the classical pathway of complement.