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

Object: To investigate whether the prevalence of positive ANA was increased in COPD with interstitial lung abnormality (ILA).

Methods: 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.

Results: 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 D_LCO was also significant. In patients with positive ANA, the scores of ILA were higher, while FEV₁, D_LCO, D_LCO % predicted, FVC, total lung capacity (TLC), and TLC % predicted were significantly lower, as compared to those with negative ANA.

Conclusion: 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, D_LCO and lung volume.