THE COMPLEMENT-SYSTEM AND SYSTEMIC-SCLEROSIS

Serum concentrations of the various complement components including th e classical and the alternative pathways were determined in 58 control healthy subjects and 80 patients with systemic sclerosis (SSC). The m ean concentrations of Clq, C2, C5, C6, C7, C9, and factor B were signi ficantly increased in the SSC patients in comparison to controls, whil e the increases were not significant for C3 and C8. C4 was an exceptio n in that the mean levels were found to be decreased, with 18 patients having levels <65% of the mean normal value. Properdin was also found to be decreased, but not significantly. We found a similarity between the pattern of serum complement component concentrations in SSC patie nts and patients with primary biliary cirrhosis, two disorders frequen tly associated in the same patients. The significance of complement co mponent patterns in these diseases is discussed.