Background Remission is the ultimate goal in rheumatoid arthritis (RA). The absence of rheumatoid factors (RF) and /or anti-citrullinated protein (CCP) antibodies, no bone erosions on conventional x-rays, the presence of low disease activity, and early therapeutic intervention are established good prognostic markers. Magnetic resonance imaging (MRI) is a well evaluated imaging technic and is increasingly used in daily practice. In this study, we prospectively investigated the prognostic performance of high-field MRI and serological biomarkers 6 months after initiation of methotrexate in patients with early RA (eRA)
Objectives To evaluate the value of high-resolution MRI of the hand as a prognostic marker for EULAR-response and remission after 6 month of MTX therapy in early RA patients
Methods Prospective cohort study on the ArthroMark cohort using 3T MRI of the hand at baseline (V0) before initiating an MTX-therapy in eRA patients, after 3 months (V3) and after six months (V6). 28 patients (Ø 56.8 years) with RF and/or CCP positive RA and a disease duration <6 months (mean16.3 weeks) fulfilling the 2010 ACR/EULAR criteria were examined. EULAR core set of variables were recorded: patient's global assessment of overall disease activity; number of tender and swollen joints, ESR and CRP. The following biomarkers were assessed by ELISA: Dkk-1, Osteoprotegerin, IL-22, MMP-3, TNF-Alpha and Neuropeptide-Y. Remission was defined as DAS28 <2.6 according to the ACR/EULAR remission criteria. MRI-scans were analysed by using OMERACT RA-MRI scoring system (RAMRIS). To adjust for intrapersonal correlation, we calculated generalized linear mixed models with time being recognized as a confounder in pretests.
Results A low RAMRIS subscore for erosions (p=0.019) or total RAMRIS score predicted response at V3 (p=0.03). No significant results were found for the other imaging markers assessed for response prediction at either V3 or V6. Concerning remission, low levels of RANKL at baseline were significantly associated with EULAR remission at V6 (p=0.033). The other markers assessed did not show significant results at either V3 or V6.
In multivariate analyses, response was predicted more accurately with the inclusion of either RAMRIS (p value LR-test =0.035), RAMRIS synovitis subscore at MCP-2 (p-value LR-test =0.035) or a combination of the two (p-value LR-test =0.042). Remission was more accurately predicted when RANKL was considered with low RANKL improving the chance of remission. In contrast to response-prediction, MRI did not significantly add to the prediction model for remission.
Conclusions Low RAMRIS scores or RAMRIS synovitis subscores at MCP-2 were predictive for therapy response after 6 months in our generalized mixed model. Baseline RANKL was able to significantly predict remission. Our data suggests that MRI and/or biomarkers may aid response prediction and facilitate patient selection for intensified therapy in the future.
Acknowledgements ArthroMark study is funded by the Federal Ministry of Education and Researche (Bundesministerium für Bildung und Forschung, BMBF, FKZ 01EC1009A).
Disclosure of Interest None declared