Iguratimod, A Synthetic Disease Modifying Anti- Rheumatic Drug (Sdmard), and Various Dmards Suppress Joint Destruction. The Pathophysiological Mechanisms of the Inhibition of Bone/Cartilage Destruction

Objective: To elucidate the radiographic outcomes for rheumatoid arthritis (RA) patients using the synthetic disease-modifying antirheumatic drug (sDMARD) Iguratimod (IGU) and other DMARDs including injectable sodium aurothiomalate, bucillamine, salazosulphapyridine, infliximab, etanercept, tocilizumab and/or abatacept.Patients and Methods: 213 patients were enrolled in this study. Total Genant-modified Sharp scores (GSS) of hands/wrists and feet at baseline and at week 104 were calculated in 31 RA patients treated with a daily dose of 25 mg or 50 mg for 104 weeks.Results: Total GSS of 31 patients at week 104 showed no progression (total GSS <= 0.84: the smallest detectable change) in 16 (52%) patients with a mean score reduction (95% CI) of-4.3 (-8.1 ~ -0.5) (p < 0.05).Conclusion: Treatment with the sDMARD, IGU showed no radiographic progression in 16 (52%) RA patients at week 104. Concerning the suppression mechanism of joint destruction by IGU and other DMARDs, we speculate that DMARDs prevent bone/cartilage destruction by inhibiting the receptor activator of nuclear factor-kappa B (NF- kB) lig and (RANKL) and through other antirheumatic actions.