Association of fibulin-3 concentrations with the presence and severity of knee osteoarthritis: A cross-sectional study

Background: Fibulin-3, a member of the extracellular matrix glycoproteins family, negatively regulates chondrocyte differentiation. This study aims to assess the correlation of fibulin-3 concentrations with the presence and severity of knee osteoarthritis. Methods: This cross-sectional study was performed in a population of 209 knee osteoarthritis subjects who received hyaluronic acid treatment and 165 healthy controls. Knee osteoarthritis diagnosis was made according to the criteria of the American College of Rheumatology. Osteoarthritis severity was scored by the Kellgren-Lawrence grading method. Synovial fluid was obtained from the knees of osteoarthritis subjects who received the treatment of hyaluronic acid injection for the first time. Serum and synovial fluid fibulin-3 concentrations were examined by enzyme-linked immunosorbent assay method. Results: Mann-Whitney U-test showed that there were higher serum fibulin-3 concentrations in the case group compared with the controls. Higher serum and synovial fluid fibulin-3 concentrations were found in knee osteoarthritis subjects compared with those with Kellgren-Lawrence grades 2 and 3. Knee osteoarthritis subjects with Kellgren-Lawrence grade 3 had higher serum and synovial fluid fibulin-3 concentrations compared with those with Kellgren-Lawrence grade 2. Serum and synovial fluid fibulin-3 concentrations were significantly correlated with Kellgren-Lawrence grading after Pearson correlation analysis (r = 0.532, P < 0.001 and r = 0.613, P < 0.001). Multinomial logistic regression analysis demonstrated a significant association between serum and synovial fluid fibulin-3 concentrations with Kellgren-Lawrence grades (P < 0.001 and P < 0.001). Conclusion: Serum and synovial fluid fibulin-3 concentrations were correlated with the presence and severity of knee osteoarthritis. (C) 2017 Published by Elsevier B.V.