Active synovitis in the presence of osteitis predicts residual synovitis in patients with rheumatoid arthritis with a clinical response to treatment.

AIM: To clarify the relationship between active synovitis/osteitis and subsequent residual synovitis (R-synovitis) in patients with rheumatoid arthritis (RA).

METHODS: Three hundred and twenty finger joints of 16 patients with active RA at baseline (Disease Activity Score with 28 joints - erythrocyte sedimentation rate > 3.2) who subsequently achieved clinical low disease activity or remission afterwards were analyzed. Synovial vascularity (SV) was assessed according to a semi-quantitative ultrasound score (grades 0-3). Active synovitis was defined by SV positivity at baseline. R-synovitis was defined by the presence of grade > 2 SV at the 24th week. Osteitis was detected by magnetic resonance imaging (MRI) at baseline as trabecular bone lesions with water content and indistinct margins.

RESULTS: Ultrasonography detected active synovitis in 116 joints at baseline. Forty-seven joints had R-synovitis at the 24th week. MRI detected osteitis in 12 joints at baseline. The presence of active synovitis with osteitis at baseline was significantly correlated with R-synovitis at the 24th week.

CONCLUSIONS: Active synovitis in the presence of osteitis predicted R-synovitis regardless of whether there was a clinical improvement in RA.