Serum levels of interleukin 17 and 22 in patients with systemic sclerosis: a single-center cross-sectional study

Systemic sclerosis (SSc) is a chronic, autoimmune disease characterized by inflammation, vasculopathy, and fibrosis of the skin and internal organs. Immunological response in SSc is still poorly understood. Cytokines play a significant role in this process leading to vasculopathy and fibrosis. In this cross-sectional study, we aimed to investigate serum levels of Th-17-related cytokines, IL-17 and IL-22, and to determine their correlation to the clinical association in SSc patients. Serum IL-17 and IL-22 levels were examined in 42 SSc patients and 29 healthy individuals. Associations between serum IL-17 and IL-22 levels and the duration of the disease, the extent of skin fibrosis, capillaroscopic findings, and involvement of the internal organs were explored. Serum IL-17 levels were not different in SSc and the control group. Serum IL-22 levels were significantly elevated in SSc patients compared to healthy individuals (p = 0.04). A positive correlation was found between the IL-22 sera levels and interstitial lung disease (p = 0.007). These results suggest IL-22 as a potential biomarker in SSc-related interstitial lung disease.