Serum levels of soluble Fas/APO-1 receptor are increased in systemic sclerosis

It has been suggested that rheumatic diseases may result from a deficit in Fas-mediated T-cell apoptosis. Recent studies have demonstrated increased soluble Fas in sera from lupus erythematosus patients. We were interested to determine whether elevated soluble Fas levels are associated with systemic sclerosis. Soluble Fas levels were retrospectively assayed using a sandwich enzyme-linked immunosorbent assay in serum from 30 patients with systemic sclerosis and 15 normal controls. Hospital medical records were retrospectively reviewed for clinical and laboratory characteristics of the patients. Soluble Fas levels were analysed in subsets of patients with limited (lcSSc) versus diffuse cutaneous systemic sclerosis (dcSSc) and correlated with inflammatory activity. In systemic sclerosis soluble Fas serum levels (lcSSc, 2.19 +/- 0.71 ng/ml, dcSSc 2.53 +/- 1.37 ng/ml) were significantly higher than in normal controls (1.26 +/- 0.36 ng/ml). However, there were no significant differences in soluble Fas levels between lcSSc and dcSSc and poor correlation between soluble Fas levels and inflammatory activity status. Detection of elevated soluble Fas might serve as a clinical marker for immunological dysregulation in systemic sclerosis, but not for inflammatory disease activity.