Prediction of Abatacept Discontinuation Using Test Reflecting Immunological Remission in Rheumatoid Arthritis

Inclusion Criteria:

• Rheumatoid arthritis (RA) patients (> pr = 18 years) fulfilling the 2010 ACR/EULARcriteria

• Associated to high levels (> 3 x upper limit of normal in UA/ml) of ACPA measured bythe usual anti-CCP(cyclic citrullinated proteins)2 test at the start of abatacepttreatment

• Receiving IV (intravenous) or SC (subcutaneous) abatacept alone or in combinationwith a conventional Disease Modyfying AntiRheumatic Drugs (cDMARD) (methotrexate,leflunomide, sulfasalasin in monotherapy or in combination) according to the usualscheme or in tapering phase

• Without intra-articular injections of corticosteroids during the last 6 months priorto down-titration of abatacept

• Having discontinued corticosteroids at he time of entrance in the study

• In deep remission (Disease Activity Score (DAS) 28 ESR (or CRP) < 2.6 withoutclinical synovitis) since at least 1 year

• In sonographic remission at the time of enrollment (absence of PD (PowerDoppler)-positive synovitis on 28 joints defined by a score < 2 on a 0-3semi-quantitative scale for each joint)

Exclusion Criteria:

• Age < 18 years

• RA negative for ACPA (anti-citrullinated proteins antibodies) or not fulfillingACR/EULAR criteria

• Abatacept discontinuation due to serious adverse event, loss of efficacy orpregnancy project