Chronic airway inflammation implicated in RA pathogenesis

Asthma and chronic obstructive pulmonary disease (COPD) may each contribute to a heightened risk of developing rheumatoid arthritis (RA), regardless of smoking status or intensity, a study has found.

The study used data from the Nurses’ Health Study I and II, including 205,153 women in the COPD analysis and 196,409 in the asthma analysis. Researchers identified 15,148 women with confirmed asthma, 3,573 with confirmed COPD and 1,060 who developed RA (63 percent seropositive) during 4,384,471 person‐years of follow-up. 

Women in the COPD vs asthma and no asthma/COPD groups were older (mean age, 52.7 years vs 42.5 and 44.4 years, respectively) and were more likely to be postmenopausal (70.3 percent vs 30.4 percent and 34.6 percent).

Cox regression analysis showed that compared with no asthma/COPD, asthma was associated with elevated RA risk (hazard ratio [HR], 1.53, 95 percent confidence interval [CI], 1.24–1.88) despite controlling for covariates, including smoking pack‐years/status. This association remained in an analysis limited to never‐smokers (HR, 1.53, 95 percent CI, 1.14–2.05).

Results were consistent for COPD, which conferred a 90-percent risk increase (HR, 1.89, 95 percent CI, 1.31–2.75). The association between COPD and RA was most pronounced in the subgroup of ever‐smokers aged >55 years (HR, 2.20, 95 percent CI, 1.38–3.51).

The present data provide evidence that chronic airway inflammation potentially plays a role in the pathogenesis of RA, researchers said. This may help identify populations at risk of RA for the purposes of research and informing clinical care.