Clinical Characteristics of Rheumatoid Arthritis Patients Achieving Functional Remission with Six Months of Biological DMARDs Treatment

Yusuke Miwa, Ryo Takahashi, Yuzo Ikari, Airi Maeoka, Shinichiro Nishimi, Nao Oguro, Tomoki Hayashi, Mika Hatano, Sakiko Isojima, Ryo Yanai, Tsuyoshi Kasama, Yoichi Toyoshima, Katsunori Inagaki, Kenji Sanada

Objective Although previous studies have reported the prognostic factors for functional remission, no reports have cited the predictive factors. Our aim was to study the predictive factors for functional remission, which is a treatment goal in rheumatoid arthritis (RA), after receiving biological disease-modifying antirheumatic drugs (bDMARDs) treatment for six months. Methods The study consisted of 333 RA patients treated with bDMARDs for six months. The following patient characteristics were investigated: age, gender, disease duration, type of bDMARDs, baseline steroid and methotrexate dosage, and levels of serum rheumatoid factor, matrix metalloprotease, anti-cyclic citrullinated peptides antibody, tumor necrosis factor-α, and interleukin-6. In our evaluation, we used the Simplified Disease Activity Index (SDAI) for RA disease activity, health assessment questionnaire disability index (HAQ-DI) for activity of daily living, Short Form (SF)-36 for quality of life, and Hamilton Depression Rating Scale (HAM-D) or Self-rating Depression Scale (SDS) to determine the patients' depression status. The subjects were divided into two groups: patients with HAQ-DI≤0.5 and HAQ-DI>0.5 at 6 months. Results A univariate analysis comparing a group of RA patients without functional remission (n=68) showed that the patients with functional remission (n=164) had the following in common compared with those without remission: younger age, shorter disease duration, lower baseline steroid dosage, lower SDAI, lower HAQ-DI, higher SF-36, and lower HAM-D. Only lower HAQ-DI scores and "mental health" score on the SF-36 were detected using a logistic regression analysis. Conclusion These findings suggested that RA patients with lower HAQ-DI and lower depression scores at baseline were more likely to achieve functional remission using bDMARDs treatment than those without these variables.