Greater large conducting airway luminal area in adult patients with interstitial lung disease.

Interstitial lung disease (ILD) encompasses pulmonary disorders characterized by chronic inflammation and fibrosis that disrupt pulmonary gas exchange. While ILD-related changes in the lung parenchyma are well-documented, less is known about how ILD affects luminal area within the large conducting airways. This retrospective, case-control study tested the hypothesis that patients with ILD would have greater large conducting airway luminal areas than healthy matched controls. Three-dimensional reconstructions of computed tomography images were used to quantify airway luminal areas in patients with ILD (n = 82; 54% female) and healthy controls matched for age, sex, and height. Patients with ILD had 16%-22% greater airway luminal areas across all seven measured large conducting airways compared to controls (all p < 0.001). Among patients with ILD, males had 17%-34% greater height-normalized airway luminal areas than females (all p < 0.05). These data provide evidence that ILD is associated with greater large conducting airway luminal area, even when matched for key demographic factors. Consistent with observations in health, males with ILD exhibited greater height-normalized airway size than females. These findings offer new insight into airway remodeling in ILD and highlight potential sex differences in airway luminal area.