SOLUBLE SERUM INTERLEUKIN-2 RECEPTORS IN PATIENTS WITH SYSTEMIC-SCLEROSIS

Objective. To determine whether soluble interleukin 2 receptor (sIL-2R ) levels correlate with natural history of disease in patients with sy stemic sclerosis (SSc). Methods. The following groups were studied: Gr oup I included 81 consecutive new patients with SSc. Group II consiste d of 21 patients with diffuse cutaneous (dc) SSc whose peripheral bloo d and affected skin had been analyzed for T lymphocyte subsets. Group III contained 38 patients with dcSSc with serial sIL-2R determinations during the course of disease. sIL-2R was performed using a commercial double monoclonal antibody ELISA technique. Results. The 81 Group I p atients with SSc had a mean sIL-2R level of 821 units compared with 35 controls, who had a mean of 389 units (p < 0.001). sIL-2R level signi ficantly correlated with the extent of skin thickening (p < 0.005). In Group II patients, sIL-2R was found to correlate with the CD4 to CD8 ratio. Blindly assessed clinical evidence of disease activity from the serial samples of 38 Group III patients was consistent with sIL-2R le vels in 83% of the samples. There was high correlation of change in sI L-2R with change in skin score over time in Group III subjects (r = 0. 71). Conclusions. These results suggest a role for T cell activation i n the pathogenesis of SSc. sIL-2R levels may be a useful adjunct to cl inical evaluation in assessing disease activity and predicting future events in patients with SSc.