OBJECTIVE: In a comparative conventional MRI, dynamic contrast-enhanced (DCE)-MRI, CT and radiography study, the authors aimed to monitor whether inflammation is reduced or even eliminated and damage halted in PsA patients receiving anti-TNF therapy.

METHODS: A 48-week prospective open-label investigator-initiated trial of 41 biologic-naive patients treated with 40 mg adalimumab every other week. Hand CT, MRI (according to the PsA MRI scoring system method) and radiography (Sharp-van der Heijde method) were obtained at weeks 0, 6 (only MRI), 24 and 48. Clinical response was assessed by the PsA Response Criteria (PsARC).

RESULTS: In the 23 PsARC responders at week 48, significant decreases from baseline in MRI synovitis (mean -2.0, P < 0.05), bone marrow oedema (BMO) (-1.3, P < 0.05), flexor tenosynovitis (-2.1, P < 0.05) and total inflammation (-6.0, P < 0.005) were observed. However, MRI signs of inflammation remained present (week 48 total inflammation score median = 9). Several DCE-MRI parameters also decreased (P < 0.05) and were correlated (ρ = 0.62) with conventional MRI total inflammation score. No statistically significant changes in bone erosion or proliferation scores were observed. With CT as the standard reference for detecting bone erosions/proliferations, sensitivity, specificity and accuracy were 100%/40%, 83%/93% and 84%/86%, respectively, for MRI, whereas corresponding values for radiography were 17%/26%, 98%/96%, and 93%/87%, respectively. Erosive progression as assessed by CT was found in 6 of 480 joints and baseline BMO was predictive (relative risk 10, 95% CI 2.1, 49).

CONCLUSION: MRI signs of inflammation decrease, but do not disappear, during anti-TNF-α therapy. No overall changes in bone erosions or proliferations were observed. On joint-level baseline MRI, BMO was related to subsequent erosive progression detected by CT.

TRIAL REGISTRATION: ClinicalTrials.gov, http://clinicaltrials.gov/, NCT01465438.