Cytokines, 25-OH vit D and disease activity in patients with juvenile-onset systemic lupus erythematosus

Background Juvenile onset systemic lupus erythematosus JO-SLE patients usually exhibit a more aggressive disease course compared to adult patients. Vitamin D deficiency is proposed to be associated with increased disease activity and flares of numerous autoimmune diseases like SLE, rheumatoid arthritis, and scleroderma. Objective To evaluate the level of IL-17, IFN-gamma, and 25-OH Vit D in JO-SLE patients versus healthy controls, and determine the correlation of those inflammatory mediators with SLE disease activity and damage scores. Furthermore, to analyze the relationship between 25-OH Vit D levels with the inflammatory cytokines (IFN-gamma and IL-17) in JO-SLE patients. Patients and methods Fifty JO-SLE patients and 25 controls were included in this study. Clinical and laboratory data of patients at the time of the study were recorded. SLE disease activity and damage were assessed using the SLEDAI-2K disease score and SLICC damage index, respectively. Plasma 25-OH Vit D, IFN-gamma, and IL-17 concentrations were determined using the human ELISA kit. Results Plasma 25-OH Vit D levels (20 ng/mL) were significantly lower in JO-SLE patients compared to (31 ng/mL) controls (P = 0.014). Plasma levels of IFN-gamma and IL-17 were significantly higher (163.5 and 25.5 pg./mL) in JO-SLE patients than (68.3 and 3 pg./mL) that of controls (P = 0.016 and P = 0.013). There was a significant negative correlation between 25-OH Vit D levels and SLEDAI-2K (R= -0.431) as well as IFN-gamma (R= -0.471) plasma level (P = 0.022 and P = 0.027). Conclusion IFN-gamma and IL-17 were significantly higher in JO-SLE patients, while 25-OH Vit D was significantly lower compared to controls. There was a negative correlation between 25-OH Vit D and each of SLEDAI-2K and IFN-gamma.