Serum tumor necrosis factor-like weak inducer of apoptosis (sTWEAK) and IL-17 levels are associated with disease activity in systemic lupus erythematosus patients with and without nephritis

Abstract

Introduction: Lupus nephritis (LN) is one of the most severe signs of systemic lupus erythematosus (SLE) and rapid diagnosis of kidney damage remains an important concern for LN. Objectives: The aim of this study was to investigate the association of the serum levels of tumor necrosis factor-like weak inducer of apoptosis (TWEAK) and interleukin 17 (IL-17) with SLE severity, renal involvement, and other clinical manifestations in lupus patients. Patients and Methods: In order to determine a better biomarker for the detection of renal damage, this study evaluated the ability of serum TWEAK (sTWEAK) and IL-17 in lupus patients with (n=25) and without (n=25) nephritis and healthy controls (n=39). Moreover, it compared the levels of these cytokines with disease activity and chronicity as well as traditional serum markers including complement C3 and C4, creatinine, and proteinuria in lupus patients. Results: Increased levels of sTWEAK and IL-17 were observed in SLE and LN groups compared to healthy controls and non-LN groups, respectively. Significant positive associations were observed between serum TWEAK and IL-17 levels and systemic lupus erythematosus disease activity index (SLEDAI), proteinuria, nephritis activity index, and some clinical manifestations (P<0.05). Discriminating the ability of the studied cytokines were not better than the utility of any markers individually. Conclusion: The serum levels of TWEAK and IL-17 in the SLE and LN groups were significantly higher than the control group and both markers were indicative of the renal disease severity; therefore, they could possibly indicate renal involvement in the lupus patients.