Background The first goal of treatment of rheumatoid arthritis (RA) is clinical remission. However, few studies have explored predictors of the remission with Abatacept (ABT) based on clinical data.
Objectives This study examined the 6-month response to ABT in a cohort of patients with established RA to explore predictors of clinical remission, a score of <2.6 disease activity based on 28 joints and C-reactive protein (DAS28-CRP).
Methods A Japanese multicenter registry database for biological treatment in RA patients was used in this study(Tsurumai Biologics Communication database). From September 2010 to November 2011, 94 RA patients received ABT at 14 institutionsaffiliated with the Department of Orthopedic Surgery, Nagoya University. Excluding 17 patients due to discontinuation at Week 24 and 1 patient due to incomplete data from analysis, for comparison 76 patients were divided into the remission group achieving DAS28-CRP<2.6 at Week 24 (n=24) and non-remission group not achieving (n=52).Patient demographics were collected, and observation parameters (TJC,SJC,visual analogue scale, CRP, erythrocyte sedimentation rate, matrix metalloproteinase3 [MMP3], and rheumatoid factor) at baseline, Weeks 4, 12 and 24, and overall disease activity indices were analyzed, using the LOCF method. The differences from baseline in each parameter were also compared. Statistical analyses were performed using Student’s t test in comparison where normality was assumed, the Mann-Whitney U-test where normality could not be assumed, a Chi-square test to calculate p values for nominal variables, with significant difference definedasp<0.01.
Results For baseline patient demographics, comparison of the remission group (n=24) and non-remission group (n=52) at Week 24 showed no statistically significant difference in sex, age, duration of RA, height, body weight, stage, class, ABT dose, use of MTX, use of oral steroids, or proportion of bio-naive patients. Predictors of remission with a statistically significant difference by Week 24 were TJC/SJC, patient’s global assessment (Pt GA), CDAI/SDAI, CRP at Week 12, and MMP3 at Weeks 0 and 12. Therefore, patients achieving TJC/SJC≤1, Pt GA≤20, low disease activity of CDAI/SDAI, ≤0.3 (negative) CRP, and MMP3 decreased by about 40 from baseline at Week 12 achieved the clinical remission of DAS28-CRP<2.6 at Week 24.
Conclusions Because ABT, immunologically, T-cell selective co-stimulation modulator, inhibits downstream inflammatory cytokines, it is said to take more time to exert its effects than do cytokine inhibitors. However, this study has identified aim indices at least at 12 weeks into treatment, as predictive factors of remission. Most such measures are included in overall disease activity indices, but the finding that a decrease of about 40 from baseline in MMP3, a surrogate marker of cartilage destruction due to synovitis can be a predictor of remission is worthy of note.
Disclosure of Interest None Declared