MRI in early rheumatoid arthritis: synovitis and bone marrow oedema are independent predictors of subsequent radiographic progression.

OBJECTIVES: To determine whether MRI and conventional (clinical and laboratory) measures of inflammation can predict 3-year radiographic changes measured by the van der Heijde Sharp score in patients with early rheumatoid arthritis (RA).

METHODS: 55 patients with RA with disease duration <1 year participated in this 3-year follow-up study. Patients were evaluated at baseline, 3, 6, 12 and 36 months by swollen and tender joint count, disease activity score based on 28-joint count, erythrocyte sedimentation rate (ESR), C reactive protein, MRI measures of synovitis, bone marrow oedema and tenosynovitis of the dominant wrist, as well as conventional x-rays of the hands and wrists.

RESULTS: All measures of inflammation decreased during the follow-up period. ESR, MRI synovitis and MRI bone marrow oedema were independent predictors of 3-year radiographic progression adjusted for age, sex and anti-citrullinated protein antibodies. The 1-year cumulative measures of MRI synovitis and bone marrow oedema provided an improved explanation of variation (adjusted R(2)) in radiographic change compared with the baseline MRI values (adjusted R(2)=0.32 and 0.20 vs 0.11 and 0.04, respectively).

CONCLUSIONS: Both baseline and 1-year cumulative measures of MRI synovitis and bone marrow oedema independently predicted 3-year radiographic progression. These results confirm that MRI synovitis and MRI bone marrow oedema precede radiographic progression in patients with early RA.