2018 Volume 64 Issue Suppl.1 Pages 134
Objective: We previously revealed that both the magnetic resonance imaging (MRI)-detected subchondral bone changes and synovial transforming growth factor (TGF)-β expression were associated with histological synovitis in end-stage knee osteoarthritis (OA) patients. However, it was unclear whether or not TGF-β signaling was activated in synovium and what OA-structural changes were associated with the activation of TGF-β signaling in the synovium in patients with end-stage knee OA.
Methods: Forty end-stage knee OA patients (female: 88%, mean age: 71.8 years, K/L grade 4) were enrolled. All participants underwent 3.0-Tesla MRI. The OA-structural changes were scored using the whole-organ MRI scoring (WORMS) method. Synovial samples were obtained from five regions of interest of the knee joint during total joint replacement surgery. The associations between WORMS and the synovial expression of TGF-β or phosphorylated (p)-Smad2/Smad2, which were semiquantitatively evaluated by immunohistochemistry, were examined.
Results: A multiple regression analysis revealed that among the MRI-detected OA changes, the subchondral bone attrition (SBA) and subchondral bone cyst (SBC) were associated with the synovial TGF-β expression (β=0.47, p<0.01) and pSmad2/Smad2 expression (β=0.42, p=0.02), respectively, in the synovium of end-stage knee OA patients. The subchondral bone changes, in which SBA and SBC were combined but bone marrow lesions were not, were associated with both the TGF-β (β=0.52, p<0.01) and the pSmad2/Smad2 (β=0.41, p=0.02) in synovium of end-stage knee OA patients.
Conclusion: TGF-β signaling is activated in the synovium and is associated with the subchondral bone changes in patients with end-stage knee OA.
