Radiographic damage is an important outcome in rheumatoid arthritis (RA). The disease course varies considerably, and there is a need for simple and reliable prognostic markers. The aim of the study was to determine the utility of early signs of extra-articular disease, manifested as rheumatoid nodules (RN), in predicting radiographic outcome.
In a cohort (n = 1589) of consecutive, newly diagnosed patients with RA, 112 cases with RN at inclusion (7%) were identified. Each case was compared to two age- and sex-matched controls without nodules from the same cohort. Radiographs of the hands and feet were performed at inclusion, after 1, 2, and 5 years and scored according to the modified Sharp van der Heijde Score (SHS; range 0-448).
Fifty-two cases with RN and 139 controls without RN had available radiographs at baseline and after 5 years. Cases were more often rheumatoid factor (RF) positive and anti-cyclic citrullinated peptide (anti-CCP) positive, and had higher disease activity and radiographic damage scores at baseline (7.9 vs. 2.5). After 5 years, there was more extensive radiographic damage among the cases (mean SHS progression 21.7 vs. 13.5). In bivariate analysis, positive RF, positive anti-CCP, SHS, and RN were strong baseline predictors for radiographic progression up to 5 years. In multivariate analysis, positive anti-CCP and SHS at baseline were independently associated with radiographic progression.
The presence of RN at baseline is a marker of extra-articular involvement and severe disease, and a predictor of subsequent joint damage.