Interstitial lung abnormality in COPD is associated with higher prevalence of antinuclear antibody

To investigate whether the prevalence of positive ANA was increased in COPD with interstitial lung abnormality (ILA).Patients with COPD from 1 September, 2019 to 31 August, 2022 were consecutively enrolled in this cross-sectional study. The characteristics, PFTs, visual assessment of ILA and emphysema on chest CT, and tests for ANA and CRP were recorded for analysis.In the study period, 100 patients with COPD were enrolled, with 90 (90.0%) males, aging 69.4 ± 8.3 years. ILA was present in 42% (n = 42) of the patients, with subpleural non-fibrotic ILA being the most common pattern. In patients with ILA, the prevalence of positive ANA was higher (45.2%) as compared to those without ILA (13.3%); between whom the difference in DLCO was also significant. In patients with positive ANA, the scores of ILA were higher, while FEV1, DLCO, DLCO % predicted, FVC, total lung capacity (TLC), and TLC % predicted were significantly lower, as compared to those with negative ANA.The presence of ILA in patients with COPD was associated with a higher prevalence of positive ANA. Patients with positive ANA tended to have lower FEV1, DLCO and lung volume.