Treatment of rheumatoid arthritis: csDMARDS versus bDMARDS. Prospective study to evaluate disease activity

Abstract

The assessment of disease activity is an essential component in the selection of therapeutic approach for the prevention of disability of patients with RA. The current study was conducted to evaluate the disease activity in patients on csDMARDs and bDMARDs after 6 months to 1-year of treatment and to determine whether the benefits of different therapies were sustained over time. For the purpose of the study were selected 220 patients with a mean age 55.05 ± 10.63 SD years, meeting the 1987 ACR classification criteria for RA. Patients were stratified according to treatment regimens into 2 age-matched treatment groups: 96 on csDMARDs and 124 on bDMARD therapy. Patient‘s assessment of disease related pain, global health and physician assessment of global health was made by visual analogue scale (VAS) – 100 mm. Disease activity was the primary outcome domain. Independent joint assessor evaluated 28 joints on baseline, 6th and 12th month of the follow-up period. C-reactive protein (CRP) was used to measure the infl ammation process. DAS28-CRP, CDAI and SDAI were calculated according to the standard formulas. Comparison was performed by analysis variance ANOVA. On baseline, patients on bDMARDs had a significantly higher mean time-averaged 28-joint disease activity score (5.03 ± 0.84 SD vs. 4.35 ± 1.20 SD, p < 0,001), CDAI (25.06 ± 7.32 SD vs. 20.83 ± 10.53 SD, p < 0.001) and SDAI (28.27 ± 8.74 SD vs. 23.19 ± 11.89 SD, p < 0.001) compared to those on csDMARDs. On the 6th month in both groups (bDMARDS and csDMARDs) we found significant decrease in mean DAS28 (p < 0.001, p < 0.001), although no significant difference in disease activity between the groups was measured by this indicator (3.75 ± 2.49 SD vs 3.90 ± 1.10 SD, p = 0.566). Patients on bDMARDs had significantly lower disease activity compared to those on csDMARDs after 6th and 12th month of treatment assessed by CDAI (13.43 ± 4.98 SD vs 16.81 ± 9.94 SD, p = 0.001; 8.65 ± 4.53 SD vs 15.86 ± 10.02 SD, p < 0.001), and SDAI (14.63 ± 5.42 SD vs 18.38 ± 10.49 SD, p < 0.001; 9.39 ± 4.92 SD vs 16.79 ± 10.5 SD, p < 0.001). Unlike results reported by DAS28-CRP which showed no change between the 6th and 12th month in patients receiving csDMARDs (3.90 ± 1.10 SD, 3.82 ± 1.12 SD, p = 0.156), we observed a statistically significant difference in all three time intervals (0, the 6th, 10th month) of the follow up period regarding to CDAI and SDAI. After a year prospective follow-up, therapy with biologic DMARDs results in sustained suppression – minimal disease activity assessed by DAS28-CRP, CDAI and SDAI, compared to patients receiving DMARDs who had moderate disease activity according to these tools. The therapy with bDMARDs was superior to csDMARDs therapy for suppressing disease activity (assessed by DAS28-CRP, CDAI and SDAI) of rheumatoid arthritis (RA) on the 6th and 12th month of the follow-up period.