Rituximab treatment for spondyloarthritis. A nationwide series: data from the AIR registry of the French Society of Rheumatology.

OBJECTIVE:To evaluate the efficacy and safety of rituximab (RTX) in several subsets of spondyloarthritis (SpA) using the data of the AIR (Autoimmunity and Rituximab) registry. METHODS:All patients receiving RTX for SpA, and prospectively included in the AIR registry from September 2005 to September 2010, were retrospectively analyzed. The response to treatment was evaluated by the Bath Ankylosing Spondylitis Disease Activity Index for axial disease, joint count for peripheral disease, and C-reactive protein reduction. RESULTS:Among the 595 patients included in the AIR registry, 26 patients with SpA from 13 centers were reported: ankylosing spondylitis (10), undifferentiated SpA (7), and psoriatic arthritis (9). Mean disease duration was 8.8 years (range 1-40). The extraarticular features found were psoriasis, 12 cases; uveitis, 4 cases; and Crohn's disease, 3 cases. The mean number of disease-modifying antirheumatic drugs before RTX was 2.4; previous anti-tumor necrosis factor (TNF) agents were taken in 23 cases. The mean number of RTX courses was 1.5 (range 1-5), with a total of 35.6 patient-years. Efficacy was noted in 11/23 cases: 3 out of 3 anti-TNF-naive patients and 8 out of 20 anti-TNF nonresponder patients. No predictive factors of response could be identified, particularly in diagnosis subsets or clinical presentation (axial or peripheral). CONCLUSION:In this nationwide study of several subsets of SpA, RTX had only a moderate efficacy that was more marked in patients who were anti-TNF-naive.