ELEVATION OF ANTI-CITRULLINATED PROTEIN ANTIBODIES PRIOR TO RHEUMATOID ARTHRITIS ONSET AND RISKS FOR DEVELOPING CHRONIC OBSTRUCTIVE PULMONARY DISEASE OR ASTHMA
Authors: Alessandra Zaccardelli et al.
The current theories for etiopathogenesis of rheumatoid arthritis (RA) assume that inflammation starts in mucosal sites (intestine, periodontal locations, lung mucosa). If the «mucosal origins hypothesis» holds true, the authors of this work assumed that damage from chronic mucosal inflammation may pre-dispose individuals with ACPA elevation to develop obstructive airway diseases, such as chronic obstructive pulmonary disease (COPD) or asthma, prior to or after clinical RA onset. In this careful analysis of a nested case-control sample of the nurses’ health study, women who had a positive ACPAs test and later developed RA had a highly increased risk for developing COPD (HR 10.8, 95%CI 1.1 -105), particularly just before RA presentation. These women were also more likely to develop new-onset asthma, regardless of pre-RA ACPA status.
Together with previous studies that showed that subclinical inflammation can be found in the airways of patients who later develop RA, this study provides additional evidence for the hypothesis that chronic airway inflammation may contribute to both RA development and respiratory outcomes. These effects were independent of tobacco smoking, although some residual confounding by other environmental inhaled pollutants (pollution, dusts) is possible. Overall, this study provides more evidence for the mucosal origins hypothesis of RA.