Systemic lupus erythematosus (SLE) is a prototypic systemic autoimmune disease. Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is cytotoxic to a wide variety of transformed cells, but not to most normal cells. This study measures serum levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6 and 10 and soluble TRAIL (sTRAIL) in patients with SLE and assesses their relation to severity of the disease. The study included 70 SLE patients and 20 healthy controls. Patients were diagnosed according to criteria proposed by the American Rheumatism Association for classification of SLE and disease activity was scored using the British Isles Lupus Assessment Group (BILAG-2004). All study participants were subjected to estimation of TNF-α, IL-6, IL-10 and sTRAIL using ELISA. Results revealed that mean disease duration was 6.5±1.5 years, mean BILAG score was 18.2±12.1, while 15 patients (21.4%) had quiescent disease. Blood levels of C3 and C4 and leucocytic count showed progressive decrease, while serum C-reactive protein and anti-double strand DNA antibodies levels showed marked increase with increased disease activity. Five patients (7.1%) were neutropenic. Serum levels of sTRAIL and IL-6 were significantly (P>0.05) higher in patients (1113.5±294 ng/ml and 60±21.5 ng/ml, respectively) than controls (354.7±47.2 ng/ml and 15.6±3.3 ng/ml, respectively) and in patients had active (1157±317 ng/ml and 64.3±20.7 ng/ml, respectively) versus patients had quiescent disease (965.4±115 ng/ml and 45.4±18 ng/ml, respectively). Serum levels of TNF-α were significantly (P>0.05) higher in patients (2.4±0.7 ng/ml) especially those with active (2.8±2 ng/ml) disease compared to controls (1.45±0.9 ng/ml). Patients with quiescent disease showed non-significantly higher TNF-α level (1.52±0.5 ng/ml) as compared to control, but significantly lower than patients with active disease. Serum levels of IL-10 were significantly lower in total patients (2.4±0.7 ng/ml) and patients with active disease (2.33±0.7) as compared to control (2.61±0.6 ng/ml) with a non-significantly (P>0.05) higher levels in patients with quiescent disease (2.61±0.6 ng/ml) than patients with active disease. Estimated serum sTRAIL, TNF-α and IL-6 levels showed positive significant correlation with calculated BILAG activity score, while estimated serum IL-10 levels showed negative significant correlation with activity score. In conclusion, SLE is associated with disturbed levels of serum cytokines and sTRAIL. These disturbances may underlie pathogenesis and/or activation of SLE as BILAG-2004 numeric scoring system significantly correlated with estimated levels of serum cytokines and sTRAIL. |
