抄録
Objective: This study was performed to evaluate the synovium of patients with rheumatoid arthritis (RA) who had undergone treatment with tumor necrosis factor α (TNFα) inhibitors.
Methods: Synovial tissue specimens were obtained during total knee arthroplasty from 62 RA patients (11 men, 51 women). Thirty-two RA patients had undergone treatment with anti-TNFα agents (biologics group: B group) and the other 30 RA patients had not (non-biologics group: N group). Fifteen RA patients had been treated with infliximab and 17 with etanercept. We further divided the B group into two subgroups: one in which the treatment was effective (B+group: DAS28 ≤ 3.2) and one in which the treatment was not effective (B−group: DAS28 > 3.2). The effectiveness of biologics was evaluated using the histological scoring system reported previously by Koizumi, by the synovitis score of the OMERACT RA magnetic resonance imaging scoring system (RAMRIS), and by the intraoperative macroscopic findings as reported by Østergaard. Koizumi's synovitis scoring system is made up of five items. The clinical laboratory data before surgery, such as matrix metalloproteinase-3 (MMP-3) levels and DAS28 scores, were also evaluated and the correlations with the histopathological findings were examined within each group.
Results: There were no significant differences in total Koizumi scores between B+, B−, and N groups. However, the scores of synovial cell proliferation were significantly different between the B and N groups. There were no statistically significant correlations between the Koizumi score and clinical data (such as the DAS28 score and MMP-3 level) for any pair of groups. Synovitis RAMRIS scores were very similar in the B and N groups, but macroscopic findings in the B group, for both B+ and B− subgroups, were significantly lower than those in the N group.
Conclusion: These results suggest that clinical data do not always reflect the conditions of severely arthritic joints in patients treated with TNF-α inhibitors.
