A Longitudinal Evaluation of Bone Erosive Damage in the Metacarpophalangeal Joints of Patients with Rheumatoid Arthritis Using Early Erosions in Rheumatoid Arthritis (EERA) Software

Abstract

In this longitudinal pilot study, magnetic resonance imaging (MRI) and Early Erosions in Rheumatoid Arthritis (EERA) software were used to quantify bone erosive damage in the metacarpophalangeal (MCP) 2-5 joints of the worst-affected hand (i.e. greatest swelling and tenderness at baseline) of patients with rheumatoid arthritis (n=35). Firstly, Spearman’s rho (rs) was used to evaluate the correlation between total change in sum erosive damage and change in functional ability, as well as the correlation between rate of change in sum erosive damage and change in functional ability. The rs (p-value) for total change and rate of change in sum erosive damage was 0.099 (0.585) and 0.104 (0.565), respectively. Therefore, the null hypothesis that neither variable was associated with change in functional ability could not be rejected. Participants were also classified into three groups based on total change in sum erosive damage (improvement, stable or progression) and were examined for possible differences in a variety of measures using an exploratory, non-statistical approach. Most notably, participants in the improvement group had more than five times the mean sum erosive damage at baseline compared to the progression group and also appeared to be the least aggresively medicated of the three cohorts. This study is the first to apply EERA in a way that helps to address clinically important questions related to change in erosive damage and functional ability. Future studies should use the ideas and concepts generated in this pilot study to further explore the use of this highly reproducible erosion quantification software, with the ultimate goal of expanding the applications of EERA in both the research and clinical settings.