Background For rheumatoid arthritis (RA) patients in remission on biological agents (BA), EULAR recommends spacing then stopping biological agent. For standardization of practices in our rheumatology department, in a prospective real life study, spacing and withdrawal biological agent was performed in patients with RA in remission according ACR-EULAR criteria.
Objectives The objective of this routine care study was to define more stringent eligibility criteria for biologic-free remission: with the underlying question: was ACR-EULAR remission (SDAI <3.3) during at least 12 month predictive of biologic-free remission? What was the percentage of relapse during the spacing period and during the withdrawal period? What was the predictive criteria of relapse after the withdrawal of the biological agent?
Methods Patients on BA excepting rituximab with criteria: ACR-EULAR 2010 RA diagnosis, identical BA for more than 1 year, remission for 1 year (DAS28 <2.6), SDAI <3.3 at the inclusion visit, corticosteroids <5mg/day were selected. The follow-up during 18 months included a spacing period of BA according to a predefined schema and a withdrawal period. Clinical, biological, ultrasonography (US) were monitoring every three months. Relapse was defined by SDAI>11.
Results 53 patients were enrolled: mean age 58 years, 72% women, 79% on methotrexate, median disease duration 11 years, 62% anti-CCPpositive, erosion in 85% of cases. Eight patients were on adalimumab, 24 on etanercept, 6 on infliximab, 11 on abatacept, 1 on certolizumab, 3 under tocilizumab. Baseline US findings revealed mean number of 1.7/28 gray scale synovitis an 0.7/28 power doppler (PD) posititive synovitis, a mean PDUS score at 2.5. Baseline US findings revealed 33/53 patients with GS-positive synovitis and 17 with PD-positive synovitis.
During the spacing period of 7 months, 19 patients have relapsed. 34 patients were able to stop their BA at the 7th month. At the 18th month, 14 patients have made the visit: 2 were in relapse, 12 were still in remission. On the 12 non-relapsing patients group, the mean DAS28 CRP was 2.14, the mean SDAI was 4.03. The median relapse was 11.8 months (9.9-1.35).
In multivariate analysis, relapse risk factors were: corticosteroids (RR: 13.78; IDC95: 3.95-48.08, p=10-3), women (RR: 2.31; IDC95: 0.96-5.55, p=0.06), disease duration greater than the median (RR: 2.18; IDC95: 1.08-4.39, p=0.029).
On the survival analysis, the principal relapse risk factor was a SDAI increase >0 during the spacing period (RR: 21.77; IDC95: 2.1-225.74, p=0.01). Were protective of relapse, methotrexate (RR: 0.07; IDC95: 0.01-0.61; p=0.016) and a DAS28 ESR <2.6 (RR: 0.18; IDC95: 0.03-1.13, p=0068).
Conclusions In this population of 53 RA in remission since at least 1 year, the predictive criteria for relapse were: steroid therapy, the disease duration, previous treatment with biological agent, no méthotrexate association. The criteria of predictability of relapse at the BA withdrawal was SDAI variation >0 during the spacing period.
Disclosure of Interest None declared