Expression of T helper 17 cells and interleukin 17 in lupus nephritis patients

Abstract

BackgroundModern data suggest that interleukin 17 (Il-17) and Il-17 producing cells play an important role in the pathogenesis of lupus nephritis (LN). It was reported that T helper 17 migrate to the kidney and contribute to inflammatory processes. Aim of the workTo measure the frequencies of peripheral blood T helper-17 (Th17) cells and IL-17 concentration in urine in systemic lupus erythematosus (SLE) patients and to study their association with disease activity and renal involvement. Patients and methodsThis work included 45 patients; 36 females and 9 males with 20 matching controls. Patients were subjected to clinical and laboratory assessments with emphasis on renal affection. The SLE disease activity index was also calculated. Expression of Th-17 cells in peripheral blood was measured by flow cytometry via the combined expression of CD3, IL-23R, intracellular IL-22, IL-17 and urinary IL-17 was measured by ELISA. ResultsThe patients’ mean age was 26.5±7.6years and disease duration was 6.03±4.3years. Th17 expression and urinary IL-17 were significantly higher in patients than controls (p=0.04 and p<0.001 respectively). Th17 cell frequencies and IL-17 levels significantly correlated with renal biopsy classification for LN (p=0.02 and p=0.04 respectively). Th17 cell expression and IL-17 levels were comparable in SLE patients with and without LN. Th17 cell frequencies significantly correlated with serum creatinine, SLEDAI and inversely with C3 (p=0.003), while IL-17 significantly correlated with CD3 cells, proteinuria and erythrocyte sedimentation rate. ConclusionPeripheral blood Th17 cell frequencies and IL-17 in urine are highly linked to LN in SLE and are promising markers of disease activity in LN. Both are valuable targets for future therapeutic applications.