BACKGROUND: The aim of this study was to evaluate the role of interleukin-17 (IL-17) level in synovia and its relationship with the severity of knee osteoarthritis (OA).

MATERIAL AND METHODS: We enrolled 226 OA patients and 106 controls in this study. The symptomatic/radiation severity of OA was assessed by the Western Ontario McMaster University Osteoarthritis Index (WOMAC) pain score/Kellgren-Lawrence (KL) grading system. Serum IL-17 levels were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS: Synovia IL-17 levels were significantly higher in OA patients compared with controls (P<0.01), and were negatively correlated with OA severity. IL-17 level gradually decreased among different phases but lacked statistical significance.

CONCLUSIONS: IL-17 might play a crucial role in the pathogenesis of OA and is closely related to pain. Blocking the IL-17 signaling pathway may delay pain related to OA.

Keywords: Biomarkers - metabolism, Case-Control Studies, Enzyme-Linked Immunosorbent Assay, Interleukin-17 - metabolism, Osteoarthritis, Knee - metabolism, Severity of Illness Index, Statistics as Topic, Synovial Fluid - metabolism