Background: Joint destruction occurs frequently in patients with psoriatic arthritis (PsA). In addition to providing insight into pathogenesis, bone marrow oedema (BMO), synovitis, effusion, and joint erosion may be used as outcome measures in PsA.
Objective: To assess the impact of adalimumab on BMO, synovitis, effusion and erosions in PsA, as measured by magnetic resonance imaging (MRI).
Methods: Fifteen patients with active PsA (≥3 tender and ≥3 swollen joints) were enrolled in an open-label pilot study. Each received adalimumab subcutaneously every other week for 24 weeks. Gadolinium-enhanced MR images were obtained at baseline and 24 weeks.
Results: MR images were available for 11 patients, pre- and post-therapy. BMO and effusion scores improved markedly after 24 weeks of adalimumab, while no significant change was noted in erosion score. An unanticipated finding, however, was lack of improvement in the MRI synovitis score, despite synovitis improvements in 9 of 19 locations evaluated.
Conclusions: Improvement in BMO and unchanged erosion scores may explain the "anti-erosive" effects of adalimumab in PsA. Persistence of BMO and synovitis on MRI suggests ongoing disease activity and supports continuation of long-term anti-TNF therapy.