Serum levels of Interlökin-37 in patients with systemic sclerosis and its' association with clinical parameters

Systemic sclerosis(SSc,scleroderma) is a connective tissue disease that pathogenesis is characterized by three hallmarks: fibrosis of the skin and/or internal organs, production of certain autoantibodies, and vasculopathy. But its specific pathological mechanism remains incompletely understood. Interleukin-37 (IL-37), a newly discovered member of the IL-1 family, has been identified as a natural inhibitor of immune responses. IL-37 is closely associated with several inflammatory diseases. Recently, studies have shown that expression of IL-37 was abnormal in autoimmune diseases, such as systemic lupus erythematosus(SLE), rheumatoid arthritis(RA). In this study, our aim was to evaluate the serum IL-37 levels in SSc patients and to investigate its association with major clinical and laboratory features. Thirty five SSc patients and thirty healthy controls were recruited. Serum IL-37 levels were assessed by enzyme-linked immunosorbent assay(ELISA). The major clinical and laboratory data of SSc patients were also recorded. The results showed that IL-37 level was lower in the serum of patients with SSc compared with controls. But this was not statistically significant(p=0,078). Correlation analysis revealed a negative correlation between serum IL-37 and C3 levels in SSc patients(p=0,046). No significant associations of IL-37 with other clinical and laboratory parameters were found. In conclusion, IL-37 level was lower in the serum of patients with SSc compared with controls; on the contrary other autoimmune diseases and it was associated negatively with C3 level. The etiology and pathogenesis of SSc is very curious and is not still clear. For understanding the pathogenetic mechanisms of the disease randomized studies with greater sample sizes are required for assessing both IL-37 and the other immunological markers. KEYWORDS, Systemic sclerosis, Interleukin-37, compleman, clinical parameters, laboratory parameters