Predictors of flare in rheumatoid arthritis patients with persistent clinical remission/low disease activity: Data from the TARAC cohort

Abstract

To identify predictors of rheumatoid arthritis (RA) disease activity flare in RA patients who achieved low disease activity (LDA) or persistent remission from the observational Thai Army Rheumatoid Arthritis Cohort study. RA patients with persistent clinical remission, defined by disease activity score 28 (DAS28) < 2.6 and LDA defined by DAS28 ≤ 3.2 for 3 consecutive months, were recruited and followed-up for at least 2 years. The flare was defined by an escalation of DAS28 ≥ 1.2 plus their physicians' decision to enhance RA treatment. Differences between sustained remission/LDA and flare groups were analyzed, by Chi-square test and unpaired Student t test. Multivariate Cox proportional hazard regression analysis was conducted to determine flare predictors. From 199 RA patients, female were 82.9%. Anticitrullinated peptide antibodies (ACPA) or Rheumatoid factor (RF) were found in 69.8% of patients. Flares occurred in 69 patients (34.9%). Multivariate analysis found that the timescale from symptoms emergence to DMARD commencement, the timescale from DMARD commencement to when RA patients showed remission/LDA, the occurrence of RF or ACPA, LDA (in contrast to remission) and the increased DAS28 score when remission/LDA was achieved and tapering DMARDs promptly when persistent remission/LDA was achieved were predictors of RA flares with hazard ratios of (95% confidence interval [CI]) of 1.017 (1.003-1.030), 1.037 (1.015-1.059), 1.949 (1.035-3.676), 1.926 (0.811-4.566), 2.589 (1.355-4.947), and 2.497 (1.458-4.276), respectively. These data demonstrated that early and aggressive DMARDs treatment approach could maintain remission espcially in seropositive patients. Tapering should be applied minimally 6 months after reaching remission.

Figure 1.

Process of recruitment.

Figure 2.

Kaplan–Meier survival curves for cumulative sustained remission/LDA rates stratified by (A) decreasing DMARDs immediately after achieving remission/LDA, (b) tobacco use, (C) Sicca symptoms, (D) the presence of rheumatoid factor or anti CCP antibodies, (E) the presence of joint space narrowing in baseline hand radiographs, and (F) achieving DAS 28 remission. DAS 28 = disease activity score 28, DMARDs = disease-modifying antirheumatic drugs, LDA = low disease activity.