Key clinical point: Women with higher levels of anti‐citrullinated protein antibodies (ACPA) prior to an RA diagnosis had increased risk of incident COPD, compared with non-RA controls.

Major finding: Elevated ACPA before RA diagnosis was significantly associated with increased risk of COPD (hazard ratio, 3.04), compared with controls, after adjusting for multiple variables, including smoking history.

Study details: The data come from a matched cohort study of 283 women with incident RA and 842 controls.

Disclosures: The study was supported by the National Institutes of Health. One of the coauthors is an employee of GlaxoSmithKline.

Commentary

The interplay between rheumatoid arthritis, anti-citrullinated peptide antibodies (ACPA) and the lung continues to be elucidated in recent research. The authors of the current study used the Nurses’ Health Studies to match women with RA to controls and determine the risk of incident COPD or asthma. These women were subcategorized as pre-RA ACPA- or pre-RA ACPA+ based on banked blood prior to diagnosis, and the women who were pre-RA ACPA+ had an increased risk of developing COPD (HR 3.04) compared to women without RA even after adjusting for variables such as smoking and age, and nearly half were diagnosed with COPD prior to RA. On the other hand, women who had incident RA were more likely to develop RA than controls regardless of ACPA status. The findings do not prove causation; most of the women who developed COPD were smokers. However, the study lends more support to the theory that ACPA formation in the airways could play a part in developing COPD as well as RA.—Arundathi Jayatilleke, MD