Assessment of Interleukin 17 in Egyptian Systemic Lupus Erythematosus Patients as a Biomarker in Disease Activity

Introduction: Systemic lupus erythematosus (SLE) is a chronic idiopathic systemic autoimmune disorder with dysregulation of adaptive and innate immune systems. Interleukin (IL)-17 is the prototypical pro-inflammatory cytokine of T helper 17 (Th17) cells. Therefore, it contributes to the pathogenesis of human SLE. Aim: The aim of the research paper was the evaluation of IL-17 level as a biomarker in the SLE cohort and its relation to disease activity and analysis of IL-17 concentration in patients with lupus nephritis and non-lupus nephritis. Methods: The research enrolled 45 SLE patients according to Systemic Lupus International Collaborating Clinics Classification Criteria (SLICC), and age and sex-matched. The patients underwent full history, clinical examination, laboratory investigation, and Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) calculation. Results: The mean age ± SD of the participants equaled 32 ± 11 years, and serum IL-17 in SLE cases was statistically significantly high (p < 0.001). No statistically significant correlations were reported between disease activity according to SLEDAI and IL-17. In addition, a statistically significant positive correlation was reported between IL-17 and ESR, and a high statistically significant negative correlation was reported between IL-17 and C3 and C4 (P < 0.001). A statistically significant positive correlation was reported between IL-17 and 24-hour urinary proteins with a Pvalue of 0.01. Conclusion: SLE cases demonstrated higher levels of serum IL-17, contributing to SLE pathogenesis. However, no statistically significant difference was reported between IL-17 and Lupus nephritis. IL-17 and SLE activity (SLEDAI) did not correlate. A statistically significant positive relation was reported between IL-17 and 24-hour urinary proteins. Additionally, a high statistically significant negative correlation was reported between IL-17 and C3 and C4.