Towards stratified treatment of rheumatoid arthritis

Background: To compare the clinical efficacy of different initial treatment strategies in autoantibodynegative rheumatoid arthritis(RA) patients. Methods and findings: Data of the tREACH trial, a stratified single-blinded randomized clinical trial with a treat-to-target strategy, were used. For this analysis, we selected all autoantibodynegative RA patients, defined as fulfillment of 2010-criteria and absence of both rheumatoid factor and anti-citrullinated protein antibody, within the intermediate probability stratum. We compared the following initial treatment strategies in our autoantibody-negative RA population: 25mg methotrexate(iMTX) per week, 400mg hydroxychloroquine(iHCQ) daily or 15mg glucocorticoids(iGCs) orally in a 10-week tapering scheme without any DMARDs. Primary outcome was the proportion of patients with active disease, defined as a disease activity score(DAS)≥2.4, after 3 months of treatment. Secondary outcomes were DAS and functional ability(HAQ) over time using a linear mixed model(LMM), in which we respectively corrected for baseline DAS and HAQ. 116 patients were included and started with iMTX(n=44), iHCQ(n=35) or iGCs(n=37). After 3 months 34%, 34% and 76% of patients respectively treated with iMTX, iHCQ and iGCs had an active disease(p<.0005 for iHCQ and iMTX versus iGCs). Our corrected LMM showed no significant difference in DAS and HAQ over time between the different initial treatment strategies. Conclusions: Initial GCs without csDMARDs are also not indicated for autoantibody-negative RA patients. However, iHCQ and iMTX show similar (early) treatment responses in this subgroup of patients, which suggests that initial treatment can be stratified for autoantibody-negative and autoantibody-positive RA, but validation is needed.