Joint swelling in patients with rheumatoid arthritis (RA) tends to recur in specific joints, suggesting the influence of local factors on joint inflammation over time, according to findings from a longitudinal study published in Annals of the Rheumatic Diseases.
Investigators conducted a sub-analysis of data from the Behandel-Strategieen “treatment strategies” (BeSt) study, a multi-center treat-to-target trial that was started in 2000, and followed patients who were newly diagnosed with RA for a median of 10 years. Patients were randomly assigned to 4 treatment groups: sequential monotherapy, step-up combination therapy starting with methotrexate, initial combination therapy with methotrexate, sulfasalazine and prednisone, or initial combination therapy with methotrexate and infliximab. Every 3 months, investigators assessed 68 joints for swelling. During follow-up assessments, they evaluated whether baseline local joint swelling was predictive of swelling in the same joint using a multilevel mixed-effect logistic regression model. Investigators employed a permutation test to assess if joint swelling was better predicted by baseline swelling of the joint itself or baseline swelling of randomly selected other joints.
There were 508 patients enrolled in the study, with a mean age of 54 (SD, 14) years. Joint swelling was persistent in 30% of joints that were swollen at baseline with a median duration of 1 (IQR, 1-2) visit. Joint swelling recurred at least once during follow-up in 46% of joints swollen at baseline.
Joint swelling at baseline was significantly associated with swelling in the same joint during follow-up (OR, 2.37; 95% CI, 2.30-2.43; P <.001) and recurrent swelling in the same joint (OR, 1.73; 95% CI, 1.37-1.59; P <.001). Baseline swelling of a particular joint was a better predictor of local joint swelling than baseline swelling of other random joints (P <.001). In addition, the duration of baseline joint swelling was significantly associated with joint swelling during follow-up (OR, 1.20 per 3 months; 95% CI, 1.19-1.21; P <.001).
The study was limited by using joint swelling as the only sign of inflammation, and not tenderness, which may have led to joint symptoms being categorized as recurrent when they were actually persistent. In addition, joint swelling assessments were not always available; 18% of the data for investigators’ analysis was missing.
The study findings “might support more intensive local monitoring, including imaging techniques if joints appear clinically no longer swollen,” the study authors wrote.
Disclosure: This research was supported by Schering-Plough BV and Centocor Inc. Please see the original reference for a full list of disclosures.
Heckert SL, Bergstra SA, Matthijssen XME, et al. Joint inflammation tends to recur in the same joints during the rheumatoid arthritis disease course. Annals of the Rheumatic Diseases. Published online August 30, 2021. doi:10.1136/annrheumdis-2021-220882