Do patients with juvenile idiopathic arthritis in clinical remission have evidence of persistent inflammation on 3T magnetic resonance imaging?

Objective Up to 90% of adults with rheumatoid arthritis (RA) in clinical remission have persistent synovitis and/or bone marrow lesions (BMLs) on magnetic resonance imaging (MRI). MRI findings in patients with juvenile idiopathic arthritis (JIA) in clinical remission have not been described. We utilized 3T MRI with contrast enhancement to examine JIA patients with hand and/or wrist involvement who were in clinical remission and compared them with a cohort of adult RA patients. Methods In total, 11 JIA patients and 10 RA patients with arthritis involving the hands and/or wrists were identified by their primary rheumatologist as being in physician-defined clinical remission, having no signs or symptoms of active arthritis and no medication changes for at least 6 months. A study rheumatologist performed a joint evaluation for tenderness, swelling, and limitation of motion, and study participants self-reported tender joint counts. The participants underwent MRI with intravenous contrast enhancement of 1 hand and wrist with a history of prior symptoms. A pediatric musculoskeletal radiologist blinded to the clinical data scored the MRIs for synovitis, tenosynovitis, and/or BMLs. Results Sixty-three percent of the JIA cohort and 70% of the RA cohort had MRI findings of synovitis, BMLs, and/or tenosynovitis. All pediatric patients with MRI abnormalities had normal physician tender and swollen joint counts. The patients' self-report of painful joint counts did not predict MRI abnormalities. Conclusion Over one-half of the patients in clinical remission had MRI evidence of persistent inflammation, defined as the presence of synovitis, tenosynovitis, or BMLs. A substantial portion of patients with JIA may have subclinical disease despite clinical remission.