Morphometric analysis of airways in idiopathic pulmonary fibrosis patients with mucous hypersecretion

Five idiopathic pulmonary fibrosis (IPF) patients with sputum since the initial period of the disease (IPF SP+, more than 15 ml/day) were compared with five IPF patients without sputum throughout the course of the disease (IPF SP-) and four control subjects without pulmonary disease matched for age and sex. No significant differences in the duration of symptoms, pulmonary functions, or glucocorticoid therapy were observed between the two IPF groups. Autopsied lungs fixed by immersion into formaldehyde were used for morphometry by digitizing computer. The volume proportion of glands to bronchial wall thickness (gland%), volume proportion of goblet cells to total epithelial layer (goblet%), and luminal mucous volume were measured in central and peripheral airways. The gland percentage in the central airways of the IPF SP+ group was 18 +/- 1% (mean +/- SE), which was significantly greater than 7 +/- 0.6% of the IPF SP- group (p less than 0.001), similar to the 6 +/- 1% of control subjects. Luminal mucous volume in the peripheral airways of the IPF SP+ group was 11 +/- 2%, which was significantly greater than 3 +/- 1% of the IPF SP- group (p less than 0.05) or 0.6 +/- 0.3% of the control subjects (p less than 0.01). Furthermore, luminal mucous volume in both the central and peripheral airways significantly correlated with gland% (p less than 0.01, each). No significant difference in other parameters such as goblet% and cell infiltration between the IPF SP+ group and IPF SP- group was observed. These findings suggest that IPF with hypersecretion is associated with mucous glandular hypertrophy and the accumulation of mucus in the airways.