Figure 7.

Goblet cell quantification and correlation with BPIFA1 and BPIFB1 protein expression in airway epithelium.

Notes: Representative images of PAS staining in a never-smoker (A), a smoker without airflow limitation (B), a patient with COPD GOLD II (C), and a patient with COPD GOLD IV (D). Quantification of the number of goblet cells in the airway epithelium of never-smokers (n=17), smokers without airflow limitation (n=28), patients with COPD GOLD II (n=32), and patients with COPD GOLD III–IV (n=11), as measured by the number of PAS⁺ cells per millimeter of basal membrane (*p<0.05, **p<0.01, ***p<0.005; Mann–Whitney U-test) (E). Correlation of BPIFA1 (F) and BPIFB1 (G) protein expression and the number of PAS⁺ cells in the airway epithelium.

Abbreviations: BPIF protein, bactericidal/permeability-increasing fold-containing protein; COPD, chronic obstructive pulmonary disease; GOLD, Global Initiative for Chronic Obstructive Lung Disease; PAS, Periodic Acid–Schiff.