Correlation of concentrations of activin A with occurrence and severity of knee osteoarthritis

Background: Activin A plays as an anticatabolic autocrine cytokine in articular cartilage. Thus, this study aims to evaluate whether activin Aconcentration is correlated with the occurrence and severity of knee osteoarthritis (OA). Methods: A total of 210 knee OA patients and 150 healthy controls were enrolled in this cross-sectional study, to evaluate the severity of OA by Kellgren-Lawrence (KL) grading method. Results: It was found that the concentration of activin A in knee OA group was higher than that in healthy subjects. Furthermore, results of of activin A concentration in serum and synovial fluid (SF) suggested that activin A concentration was the highest in Kellgren-Lawrence (KL) grade 4, and the lowest in KL grade 2. Concentrations of activin A in serum and SF showed significant correlation with disease severity measured by KL grading criteria. Conclusions: It was indicated that concentrations of activin A in serum and SF showed a positive correlation with the occurrence and severity of knee OA.