Brown AK et al. (2008) An explanation for the apparent dissociation between clinical remission and continued structural deterioration in rheumatoid arthritis. Arthritis Rheum 58: 2958–2967

Previous studies of rheumatoid arthritis (RA) have demonstrated that synovial inflammation can persist even when patients are in a state of clinical remission. A longitudinal study of a group of such patients has now suggested a direct relationship between subclinical synovitis and joint structural deterioration and, further-more, that inflammation detected by MRI and musculoskeletal ultrasonography could predict subsequent radiographic progression.

The study cohort included 102 patients with RA receiving conventional treatment with DMARDs who were determined by their rheumatologist to be in clinical remission. After 1 year, however, despite a lack of change in overall disease activity, 17 of 90 (19%) patients for whom imaging at both time points was available showed significant radiographic disease progression.

The likelihood of deterioration over 12 months was associated with the baseline findings of positive power Doppler signal (odds ratio [OR] 12.21; P <0.001), power Doppler score (OR 4.0; P <0.001) and MRI-detected synovitis score (OR 2.98; P = 0.002); no such associations were found between deterioration and baseline clinical scores. The results confirm earlier findings that joint deterioration can persist despite clinical remission, and point to subclinical synovitis as the cause.

The authors contend that conventional remission criteria are insufficiently sensitive to detect ongoing inflammation in states of low RA disease activity, and propose that imaging modalities, such as MRI and ultrasonography, should be used instead.