Ultrastructure of bronchial epithelium in children with chronic or recurrent respiratory diseases.

The ultrastructure of the bronchial epithelium in three children with recurrent bronchopneumonia, four patients with cystic fibrosis and two with Kartagener's syndrome was studied. The children with recurrent bronchopneumonia and those with Kartagener's syndrome had mostly changes in the pseudostratified ciliated epithelium, and two of them had ultrastructural signs of developing squamous metaplasia. Developed stratified squamous epithelium was found in three of four patients with cystic fibrosis and in one patient with recurrent bronchopneumonia. The squamous epithelium showed striking pathological changes, but, only the oldest patient with cystic fibrosis showed signs of onset of keratinization. Both patients with Kartagener's syndrome had the defect of dynein arms typical of the immotile-cilia syndrome. In the youngest patient the partial absence of dynein arms was combined with a defect in the radial structures of the axonemes.