Whole-body Magnetic Resonance Imaging Inflammation in Peripheral Joints and Entheses in Axial Spondyloarthritis: Distribution and Changes during Adalimumab Treatment.

OBJECTIVE

To investigate the distribution of whole-body magnetic resonance imaging (WB-MRI) inflammatory lesions of peripheral joints and entheses, and their response to adalimumab (ADA) treatment and agreement with clinical measures of disease activity in patients with axial spondyloarthritis (axSpA).

METHODS

Explorative analysis of an investigator-initiated randomized controlled trial of ADA. WB-MRI was performed at weeks 0, 6, 24, and 48. Detailed analyses of WB-MRI lesions in peripheral joints and entheses were performed, including agreement with clinical measures of disease activity.

RESULTS

WB-MRI inflammatory lesions were most frequently observed in the acromioclavicular, metatarsophalangeal, and wrist joints (> 10% of joints), and at the greater trochanter, calcaneal insertion of the Achilles tendon, and ischial tuberosity (> 15% of entheses). Inflammation resolved in ≥ 2/3 of involved sternoclavicular, metacarpophalangeal, first carpometacarpal, hip, and tarsometatarsal joints, and pubic symphyses and medial femoral condyles. In contrast, inflammation resolved in ≤ 1/6 of involved acromioclavicular joints, knee joints, and supraspinatus tendon insertions at humerus. Tenderness of joints and entheses agreed poorly with WB-MRI inflammation (κ < 0.40). Joint tenderness resolved more frequently in MRI-positive than MRI-negative joints (8/13, 62% vs 9/34, 26%) after 6 weeks of active treatment.

CONCLUSION

Inflammatory lesions of peripheral joints and entheses in patients with predominantly axSpA, and changes therein, can be mapped using WB-MRI, and it may contribute to differentiate between inflammatory and noninflammatory joint tenderness. (Trial registration: ClinicalTrials NCT01029847).