Serum interleukin-17 expression in a group of Egyptian patients with juvenile systemic lupus erythematosus

Background: Systemic lupus erythematosus (SLE) is a chronic multi-organ systemic autoimmune disease. Interleukin-17 (IL-17) is a powerful proinflammatory cytokine that is involved in the development of several autoimmune diseases, including SLE. Objective: We aimed to evaluate the serum IL-17 expression in pediatric SLE and correlate this to the disease activity and other biomarkers of disease activity . Methods: Thirty-six patients diagnosed with pediatric SLE were enrolled in the study and were classified according to the SLE disease activity index (SLEDAI) score into two subgroups; mild activity (SLEDAI <5) and moderate to severe activity (SLEDAI ≥ 5). Routine laboratory work-up of SLE was done. IL-17 level was assessed by ELISA in the patients’ group (n=36) as well as in 17 age and sex-matched healthy subjects. Results: Our patients were 32 females (88.9 %) and 4 males (11.1 %). Their mean age at enrollment was 13.7 ± 2.7 years. The median (IQR) serum IL-17 level was significantly higher in patients than controls [138 pg/nl (68.5-200.15) versus 8.6 pg/nl (5.98-11.55) respectively]. There was no significant correlation between serum levels of IL-17 levels and disease activity scores. SLE patients with mild activity were comparable to those with moderate to severe activity in terms of IL-17 expression. Conclusion: SLE in children is associated with a significant increase in serum IL-17, whatever the activity status is, suggesting a potential role in the pathogenesis of the disease. Our conclusion is limited by the sample size.