FIG. 1.

Immunohistochemical staining of pulmonary tissues from patients without CF and patients with CF. (A) In patients without CF, antibody 1G9-1C2 to H-DDDDDDD-OH stained very little antigen in the apical cytoplasm of the bronchial and bronchiolar epithelium and in the cytoplasm of pulmonary endothelial cells and sporadic alveolar macrophages (in all of three tissues examined). From 10 to 30% of bronchial and bronchiolar epithelial cell nuclei were also stained. (B) In patients without CF, robust cytoplasmic staining of alveolar type I epithelium was seen (in all of three tissue sections examined; 60 to 90% of cells were stained). From 60 to 90% of alveolar epithelial cell nuclei were also stained. (C) In patients with CF, moderate staining of antigen was seen in the apical cytoplasm of the bronchial and bronchiolar epithelium (in all of three tissue sections examined; 60 to 90% of cells were stained). From 60 to 90% of bronchial and bronchiolar epithelial cell nuclei were also stained. (D) In patients with CF, no cytoplasmic staining of alveolar type I epithelium was seen (in all of three tissue sections examined; only 10 to 30% of the cells were stained). Less than 10% of alveolar epithelial cell nuclei were stained.