RESUMO
OBJECTIVES: Apoptosis is induced by binding of death receptor ligands, members of the tumor necrosis factor (TNF) superfamily, to their cognate receptors. It is suggested that TNF-related apoptosis inducing ligand (TRAIL) is involved in pathogenesis of juvenile-onset systemic lupus erythematosus (JSLE). This study aimed to assess TRAIL concentrations in sera of JSLE children and to determine their potential relationship with disease activity, anti-double-stranded DNA (anti-dsDNA) levels, neutropenia and renal involvement. METHODS: Circulating levels of TRAIL were measured by enzyme-linked immunosorbent assay (ELISA) in serum samples obtained from 40 JSLE patients (20 with active and 20 with inactive disease) and 20 controls. RESULTS: The mean (SEM) serum TRAIL concentration in JSLE was 1750.7 (440.2) pg/mL. Serum TRAIL concentrations in patients were higher than those in controls (P < 0.01). Serum TRAIL concentrations for children with inactive disease (1854.8 [485.4] pg/mL) and those with activity (1646.6 [390.6] pg/mL) were statistically comparable. JSLE children with positive anti-dsDNA antibodies had significantly higher TRAIL levels (mean = 1846 [456] vs. 1455 [325] pg/mL; P < 0.05). Serum TRAIL concentrations were significantly higher in classes III and IV nephritis compared to classes I and II nephritis (1970 [512] vs. 1330 [331] pg/mL; P < 0.01). Serum TRAIL concentrations in patients with neutropenia were higher than those without neutropenia (1805 [505] vs. 1516 [400] pg/mL; P = 0.042) and in controls (P = 0.024). CONCLUSIONS: Our data indicate that an increased level of TRAIL is a feature of JSLE that correlates with disease activity, anti-dsDNA titers neutropenia and lupus nephritis.