Disease activity and the course of elbow joint deterioration over 10 years in the patients with early rheumatoid arthritis

One hundred and eighteen elbows in 59 patients who started treatment using disease-modifying antirheumatic drugs (DMARDs) in the first year of the disease were followed-up for more than 10 years without biologic agents. Using annual radiographs of the elbow joint, Larsen grade (LG) was determined, and bone absorption ratio (BAR), cortical thickness ratio (CTR) in the humerus, and olecranon thickness ratio (OTR) were calculated. Disease activity was determined by disease activity score (DAS)28-C-reactive protein (CRP)(3) at 3- or 4-month interval throughout the follow-up period. At 10 years, 30 elbows were in LG III or more, the more deteriorated (MD) group, and 88 elbows were in LG II or less, the less deteriorated (LD) group. In the radiological assessment, the mean LG, BAR, CTR, and OTR progressed with time linearly during 10 years. In the comparison between the MD group and the LD group, there was a significant difference in the magnitude of change in CTR (Delta CTR; P=0.0064), BAR (Delta BAR; P=0.0100), and OTR (Delta OTR; P=0.0051). There was a significant difference in the mean DAS28-CRP(3) (0-2 and 0-10 years) between the two groups (P=0.0017 and 0.00002). The cut-off value of mean DAS28-CRP(3) (0-2 years), which indicated further progress to the MD group at 10 years, was 3.15. It is important to keep disease activity in low level to prevent progression of the elbow joint deterioration in the patients with RA.