Repair of erosions in patients with rheumatoid arthritis treated with etanercept: magnetic resonance imaging findings after 1 year of follow-up

Abstract

Objectives: To monitor repair of bone erosions using magnetic resonance imaging (MRI) in patients with rheumatoid arthritis (RA) during etanercept combination therapy.

Method: The study population comprised 29 RA patients [biologic-naïve, 28-joint Disease Activity Score (DAS28) ≥ 3.2] starting etanercept combination therapy with disease-modifying anti-rheumatic drugs (DMARDs) and completing the 1-year study period with the same treatment. Clinical and laboratory assessments and MRI of the hand were performed at baseline and at 1 year. MRI findings were scored by two readers using the Rheumatoid Arthritis MRI Scoring System (RAMRIS). Both readers were blind to the chronological order of the MRI scans, the identity of the patients, and clinical and other imaging data. Tenosynovitis was also scored. The intra- and inter-reader intraclass correlation coefficients (ICCs) were calculated, along with the sensitivity to change with the smallest detectable difference (SDD). Repair of erosions was defined as a RAMRIS score of at least 1 point lower than baseline.

Results: The mean RAMRIS score for erosions did not change but all other inflammatory MRI parameters decreased significantly. In 19 patients, the RAMRIS score for erosions remained unchanged after 1 year. In five patients the score decreased after 1 year, although the decrease exceeded the SDD in only one patient (3.4%).

Conclusions: Etanercept combined with DMARDs stopped the progression of erosions, as measured by the RAMRIS, in 82.8% of our RA patients and occasional repair of bone erosions occurred after 1 year of treatment.

Acknowledgements

We are indebted to Sergi Mojal for help with the statistical analyses. We also thank Silvia Sanchez (Department of Rheumatology, Hospital del Mar) for her help with the metrology of the patients. Writing assistance was provided by Thomas O’Boyle and funding by Pfizer.