High-resolution ultrasound confirms reduced synovial hyperplasia following rituximab treatment in rheumatoid arthritis

Abstract

Objective. To assess the response of RA patients to rituximab (RTX) treatment using a sensitive imaging technique for synovitis. Methods. Twenty-three RA patients were treated with two 1000-mg infusions of the B-cell depleting antibody, RTX, in an observational protocol. Clinical response was assessed by the European League Against Rheumatism (EULAR) response criteria. High-resolution grey-scale and colour-coded power Doppler (PD) ultrasonography was performed at baseline and 6 months after RTX. The second to fifth MCP and PIP joints were bilaterally examined with joints in a neutral 0 position from a palmar view and scored from 0 to 3. Results. Median disease activity score (DAS28) improved from 5.03 to 3.56 (P=0.001), which corresponded to a EULAR moderate response in 11 of 23 patients and a EULAR good response in another 6 patients. Improved control of disease activity by RTX was also indicated by tapering of median daily corticosteroid doses from 10 to 5 mg, without flare ups. Mean grey-scale scores correlated with the swollen joint count at baseline (r=0.484, P=0.022) and month 6 (r=0.519, P=0.011). Mean grey-scale scores improved upon RTX from a 0.90 median (range 0.13-1.87) to 0.75 (range 0.19-1.50, P=0.023). Frequency of PD positive joints was low (6.1%) at baseline and did not significantly change following RTX treatment. Conclusions. High-resolution grey-scale ultrasonography (US) examination confirmed reduced synovial hyperplasia, but the applied PD method displayed no significant changes. Therefore, only grey-scale US is recommended in follow-up examinations after RTX treatment. © The Author 2009. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved.