Non-Smokers COPD have a Dominant Imaging Phenotype of Chronic Bronchitis and less Emphysema

<bold>Introduction:</bold> COPD in non-smokers is increasingly recognized as a consequence of exposure to gases, vapors, and dust (VGDF). Advances in CT scan resolution enable identification of morphological phenotypes, contributing to precise medical interventions. <bold>Aim:</bold> To characterize CT patterns among COPD patients without significant smoking history compared to smoking-related COPD. <bold>Methods:</bold> We conducted an observational retrospective study. People with a COPD diagnosis and ≤10 pack-year of smoking history (non-smoker(NS) COPD) Were matched by sex and age with COPD patients with a smoking history of ≥20 pack-year (Smoker(S) COPD). We compared CT scans performed during stability between the groups. Data on occupational exposure documented in patients' medical records were collected. Radiographic characteristics were evaluated using the Bhalla score and "3DSlicer" software for quantitative analyses. Airway characteristics and total lung tissue density averages were measured. <bold>Results:</bold> 115 patients were included, 58 NS-COPD and 57 S-COPD. NS-COPD exhibited more mucus plugs than S-COPD (13.8% vs. 1.7%, p=0.013) and a higher density of the bronchial wall (213HU±101 vs. 254HU±69, p=0.015). Emphysema was absent in 81% of NS-COPD compared to 50.8% in S-COPD. Study groups did not differ in the presence and severity of bronchiectasis.40.4% of NS-COPD patients had a known occupational exposure to VGDF Specific CT patterns were not identified in the exposed group. <bold>Conclusions:</bold> COPD patients without significant smoking history have more mucus plugs and less emphysema than smoking-related COPD. These features may relate to a “bronchitis” phenotype in NS-COPD.