Background Remission or low disease activity (LDA) are the main treatment targets in Rheumatoid Arthritis (RA). Different remission criteria have been developed and differ between studies. The advent of biologic disease-modifying antirheumatic drugs (DMARDs) allowed a proportion of patients to reach these goals.
Objectives We aimed at evaluating remission, sustained remission and LDA in “real life” RA patients treated with first line anti-TNF agents by different remission criteria. We evaluated the concomitant prednisone (PDN) and conventional synthetic (cs) DMARDs treatment.
Methods We analysed retrospectively remission and LDA in 298 RA patients [age 54.5±13.3 years, 242/56 female/male, 92 early RA, 206 longstanding RA, baseline disease activity by 28 joint Disease Activity Score (DAS28) 5.2±1.3, 79.6% on concomitant csDMARDs, 49.3% on PDN] treated from 2008 to 2014 in the University of Rome Tor Vergata with first line anti-TNF drugs (120 Adalimumab 40mg/other week and 178 Etanercept 50mg/weekly). Remission and LDA were evaluated according to DAS28, Simplified Disease Activity Index (SDAI) and Clinical Disease Activity Index (CDAI) at three time points: 6 months, 1 and 2 years after the start of anti-TNF. Statistical analyses were performed using McNemar and Fisher tests.
Results At 6 months remission was achieved in 18-24% of patients, at 1 year in 21-26% and at 2 years in 15-17% of cases. (Figure 1A). No significant difference was demonstrated comparing CDAI, SDAI and DAS28 remission. Remission at two consecutive time points was detected in 17.8% (DAS28), 17.1% (SDAI) and 14.8% (CDAI) of patients, while sustained long-term remission (at the three time points) was observed in 5% (CDAI and SDAI) and 4.3% (DAS28) of patients. LDA was detected in 33-45% of patients at 6 months, in 31-42% at 1 year and in 24-31% of patients at 2 years of treatment. DAS28 allowed identifying less patients in LDA compared with CDAI at 6 months and 1 year of treatment (p=0.01 and p=0.03) (Figure 1B). A higher number of early RA patients achieved remission than longstanding RA patients at 6 months (p<0.05 by CDAI and SDAI), 1 year (p<0.05 by DAS28 and SDAI, p=0.0001 by CDAI) and 2 years of treatment (p<0.05 by DAS28, p<0.01 by CDAI and SDAI) (Figure 1C-E). Likewise, a higher number of early RA patients achieved LDA than longstanding RA at 1 year (p<0.01 by DAS28 and CDAI, p<0.05 by SDAI) and at 2 years (p<0.05 by DAS28 and SDAI) (Figure 1F-H). During anti-TNF treatment a significant reduction of the number of patients on PDN was observed at 6 months, 1 and 2 years compared with baseline (p<0.0001 for all comparisons). Concomitant csDMARDs were reduced at 1 and 2 years compared with baseline (p<0.01 for both comparisons).
Conclusions RA patients treated with first line anti-TNF drugs in routine clinical care achieved remission in 15-26% and LDA in 24-45% of cases according to the various indices allowing the reduction of PDN and csDMARDs treatment. DAS28 appeared more stringent than CDAI in identifying patients in LDA. Only a small proportion of patients (5%) achieved sustained long-term remission by the various indices. Anti-TNF treatment in early RA patients allowed better results compared with those in longstanding ones.
Disclosure of Interest None declared