To assess the efficacy of etanercept in reducing tenosynovitis evaluated by MRI of the hand (h-MRI) in patients with active rheumatoid arthritis (RA) refractory to disease-modifying antirheumatic drug (DMARD) after 6 weeks of treatment.
31 patients with active RA defined by a disease activity score (DAS28) >3.2 and synovitis in the hands were randomised into two groups: 19 patients received 50 mg weekly subcutaneous etanercept added to previous DMARD treatment and 12 patients continued with previous DMARD therapy. Clinical evaluation, blood tests, functional capacity evaluation and h-MRI were performed at the start of the investigation and at week 6. Tenosynovitis was evaluated on T1-weighted sequences with fat suppression after gadolinium as the presence of a peritendinous signal enhancement on axial images using a new method including wrist and finger tendons. The reliability, sensitivity to change and responsiveness of this method were also evaluated.
Scores for tenosynovitis showed a significant reduction in the etanercept group compared with placebo (p=0.01) after 6 weeks of treatment. Adding MRI joint synovitis to tenosynovitis scores gave an even higher significant reduction in the etanercept group (p=0.007). A positive and statistically significant correlation between tenosynovitis and DAS28, erythrocyte sedimentation rate and C-reactive protein was found, but not with functional capacity. Responsiveness for tenosynovitis was small but was higher when joint synovitis scores were added.
Addition of etanercept significantly reduced MRI tenosynovitis of the wrist and fingers in patients with active RA refractory to DMARD treatment. The method of scoring tenosynovitis showed good reliability and moderate responsiveness.