MRI and ultrasound predictors of progression to inflammatory arthritis in anti-CCP–positive individuals with musculoskeletal symptoms without clinical synovitis: a prospective cohort study

Objectives This study aims to evaluate the prevalence of magnetic resonance imaging (MRI) and ultrasound features in anti-cyclic citrullinated peptide (anti-CCP) positive individuals with musculoskeletal symptoms without clinical synovitis (CCP+ at-risk), and compare their prognostic value for progression to inflammatory arthritis (IA). Methods Overall, 130 CCP+ at-risk underwent baseline contrast-enhanced 3 T MRI of the dominant/most symptomatic hand and both feet. Images were scored for synovitis, tenosynovitis, osteitis, and erosions using Rheumatoid Arthritis Magnetic Resonance Imaging Score (RAMRIS) by a rheumatologist and a radiologist. Ultrasound used a 36-joint and 18-tendon protocol for the assessment of synovitis, tenosynovitis, and bone erosions. Associations between imaging findings, clinical variables, and progression to IA were assessed using Cox models with prespecified MRI (binary and continuous score) and ultrasound (individual lesions and overall positivity) parameterisations. Results At baseline, ≥1 RAMRIS abnormality was present in all CCP+ at-risk individuals (including ultrasound-negative individuals), while ultrasound abnormalities were detected in 25.4%. Over a median follow-up of 36.5 months, 48 (36.9%) progressed to IA. Hand tenosynovitis was the only MRI feature consistently associated with progression across binary and continuous analyses. Ultrasound-detected bone erosions were the most consistently predictive ultrasound feature. A composite of MRI tenosynovitis and ultrasound-detected erosions showed an additional increase in risk, highest in individuals with both features (hazard ratio 5.83). Conclusions In this cohort of CCP+ at-risk undergoing contemporaneous ultrasound and MRI, MRI-detected hand tenosynovitis and ultrasound bone erosions independently predicted progression to IA. Their combination identified those at the highest risk, supporting complementary roles for both modalities. The feasibility and cost-effectiveness of combined hand MRI and extensive ultrasound require evaluation.