Increased serum sFas, sTRAIL, and reduced sFasL in juvenile-onset systemic lupus erythematosus

The aims of this study were to assess serum Fas, FasL, TRAIL, and Bcl-2 levels in patients with juvenile-onset systemic lupus erythematosus (JSLE) and to evaluate their relations with disease activity parameters and nephritis. Forty-eight JSLE patients, 33 juvenile idiopathic arthritis (JIA, inflammatory controls) patients and 40 healthy controls were enrolled. sFas, sFasL, sTRAIL, and sBcl-2 serum levels were measured by ELISA. Disease activity parameters included SLEDAI score, ESR, anti-dsDNA antibodies, C3, and C4 levels. Thirty-five JSLE patients had nephritis and 32 patients were classified as having active disease (SLEDAI ≥4). Statistical analysis methods included Mann-Whitney test and Spearman's rank test. JSLE patients had significantly increased sFas serum levels compared with healthy controls (median 177.6 vs. 117.5 pg/mL; p = 0.0001), higher sTRAIL (median 484.6 vs 270.8 pg/mL; p = 0.02), and reduced sFasL (median 0.05 vs 0.3 ng/mL; p = 0.0002). The same results were observed for JSLE patients with active disease and for patients with nephritis. Additionally, sFas levels in JSLE patients directly correlated with SLEDAI score (r = 0.40; p = 0.009), and sTRAIL levels were increased in JSLE patients with neuropsychiatric disease compared with those without this involvement (median 667.9 vs. 216.2 pg/mL; p = 0.03). Otherwise, sBcl-2 levels of JSLE patients were similar to healthy controls. JIA patients had sFas, sFasL, sTRAIL, and sBcl-2 serum levels similar to JSLE patients and to healthy controls. In summary, this study characterized in JSLE a distinct profile from adult SLE that comprises increased sFas, sTRAIL, and reduced sFasL, notably in patients with active disease and with nephritis.