Levels of soluble fas/APO‐1 /CD95 in systemic lupus erythematosus and juvenile rheumatoid arthritis

Abstract
Objective. To quantify soluble Fas/APO‐1 (sFas/APO‐1 ) protein in the serum of patients with systemic lupus erythematosus (SLE) and juvenile rheumatoid arthritis (JRA). Methods. Soluble Fas/APO‐1 was quantified using a sandwich enzyme‐linked immunosorbent assay. Disease activity in SLE patients was assessed by the SLE Disease Activity Index. Results. Increased serum sFas/APO‐1 levels were observed in only 1 of the 27 SLE patients (4%) and 3 of the 10 JRA patients (30%). Conclusion. Increased levels of sFas/APO‐1 occurred infrequently in SLE, and the levels were lower than 10 ng/ml. Increased levels of sFas/APO‐1 are not specific for SLE. Soluble Fas/APO‐1 is unlikely to be of major pathogenetic significance in SLE.