Evaluation of the relationship between IL-10, IL-17, IL-23 levels and disease activity of systemic lupus erythematosus and vitamin d metabolism

Purpose: Systemic Lupus Erythematosus is a chronic, autoimmune, inflammatory disease and its pathogenesis is still unknown. Many studies have shown that IL-10, IL-17 and IL-23 play a role in the pathogenesis of SLE. Vitamin D is involved in the immune system as well as the effects on bone metabolism. So it is thought to be taking a part in the pathogenesis of autoimmune diseases. In this study, we aimed to determine the relationship between serum levels of IL-10, IL-17, IL-23, vitamin D and clinical manifestations of SLE. Method: Our prospective study was aproved by the Ethics Committee of Adnan Menderes University. Forty patients with SLE and 20 healthy controls were included in this study. Medical histories, physical examination and laboratory findings were noted. Serum IL-10, IL-17 and IL-23 levels were serologically investigated by ELISA method, 25(OH)D vitamin levels were by HPLC (high-performance liquid chromatography) method in all SLE patients and control group. Statistical analysis of the differences between groups was assessed by Mann-Whitney-U and Kolmogorov-Smirnov tests in SPSS 22. A p-value of <0.05 was considered statistically significant. Results: There was no significant difference for IL-10 and IL-17 levels between SLE patients and control group (p:0,333 p:0,990 respectively). IL-23 levels were significantly higher in the patient group compared to the control group and it was statistically significant (p<0,001). There was no significant relationship between IL-23 levels and disease activity, renal involvement or duration of disease (p>0,05). Vitamin D levels were lower in the patient group compared to the control group and it was statistically significant (p:0,003). There was a significant correlation between IL-23 and vitamin D levels (p:0,019). There was no significant relationship between vitamin D levels and disease activity, renal involvement, usage of quinine or steroids (p>0,05). However, there was a significant correlation between vitamin D levels and duration of disease (p:0,020). Conclusion: Although there are studies suppporting the role of IL-10 and IL-17 in the pathogenesis of SLE in the literature, there was no significant difference between patients and healthy controls in our study. IL-23 levels were significantly higher in SLE patients than in the control group. Vitamin D levels were significantly lower in SLE patients than in the control group. Vitamin D levels were correlated with duration of disease and IL-23. High IL-23 levels in SLE patients can be a target in SLE and other otoimmune diseases. There is a need for more comprehensive studies which evaluate IL-23 levels in SLE patients. K Key Words: Systemic Lupus Erythematosus, IL-10, IL-17, IL-23, Vitamin D.