Increased risk of COPD linked with Elevated Anti–Citrullinat
A Study was conducted to investigate the elevation of anti–citrullinated protein antibodies (ACPAs) before diagnosis of rheumatoid arthritis (RA) and risks for chronic obstructive pulmonary disease (COPD) or asthma.

A matched cohort study was conducted among women who donated blood. By age, cohort, year, and menopausal variables, women with incident RA after blood draw were matched to three controls. A research assay or cyclic citrullinated peptide in a subset described preRA ACPA positivity as more than 99th percentile of control distribution. The hazard ratios (HRs) for incident COPD or asthma associated with preRA, preRA ACPA+, or preRA ACPA– phenotypes were measured using Cox regression and compared to nonRA controls.

--283 women who were pre-RA were analyzed and 842 controls; blood was donated a mean ± SD of 9.7 ± 5.8 years before RA diagnosis.

--59 women were pre-RA ACPA+. There were 107 cases of incident COPD and 105 incident asthma cases during 21,489 person-years of follow-up.

--Pre-RA ACPA+ was associated with increased COPD risk (HR 3.04) after adjusting for covariates including smoking pack-years. Pre-RA ACPA+ had an HR for asthma of 1.74, similar to the risk of asthma for pre-RA ACPA– (HR 1.65).

And compared to controls, women with elevated ACPA before RA diagnosis had a higher risk of developing COPD. Regardless of pre-RA ACPA status, women who later developed RA were more likely to develop asthma than controls.