For patients with rheumatoid arthritis (RA) in remission who are receiving disease-modifying antirheumatic drugs (DMARDs), radiographic progression correlates with imaging-detected synovitis as measured by power Doppler activity. In contrast, patients with disease in remission who are receiving the combination of tumor necrosis factor (TNF) blockade with methotrexate (MTX) (combination treatment) have reduced radiographic damage for the equivalent clinical state. We undertook this study to determine whether the difference in radiographic outcome is a result of more complete suppression of imaging-detected synovitis.
One hundred patients with RA in remission (Disease Activity Score in 28 joints [DAS28] <2.6) for at least 6 months while receiving either combination treatment (n = 50) or DMARDs (n = 50) were matched for clinical variables. Ultrasound of metacarpophalangeal joints 1-5 and the wrist joints was performed. Remission according to imaging results was defined as a score of 0 for both grey scale synovitis and power Doppler activity.
In patients receiving combination treatment or DMARDs (median DAS28 1.65 versus 1.78, median disease duration 120 months versus 90 months, and median duration of remission 13 months versus 18 months), the proportion with remission according to imaging results was not significantly different (10% versus 16%, respectively). The combination treatment group had more grey scale synovitis (P < 0.001) but similar power Doppler activity (48% versus 60%, respectively; P = 0.229) in any joint as compared with the DMARD group. Results were not affected by stratification for duration of disease or remission.
In RA patients with disease in remission, imaging-detected synovitis persists, with power Doppler activity seen in >or=48% of the patients regardless of therapy. These results suggest that superior radiographic outcomes in patients treated with the combination of TNF blockade and MTX may not be due to complete suppression of imaging-detected synovitis.