Bronchial secretions and bronchial mucosa in children with cystic fibrosis: comparison of bronchoscopic, biochemical, bacteriological, microscopic and ultrastructural findings.

: In children (mean age 12.1 +/- 2.9 years) with cystic fibrosis, 44 bronchoscopic examinations were done under general anaesthesia with muscle relaxation using a Friedel type ventilation bronchoscope. The endoscopic picture of the mucous membranes was compared with the state of the bronchial secretions, its bacteriologic findings and content of acid mucopolysaccharides and DNA fibres (semiquantitative estimations). In all patients biopsy of the mucous membrane (central part of the bronchial tree) was performed for light and electron microscopy. The degree of reddening, swelling of the mucous membrane and hypersecretion was in some agreement with the intensity of the cellular infiltration and the production of pus (microscopic investigation). Secondary ultrastructural changes were detected in nearly all children, consisting of cellular oedema, swelling of mitochondria, dilatation of the endoplasmatic reticulum, protrusion of cells and fusion of cilia, enlarged intercellular spaces, thickening of the epithelial basal membrane, increased number of goblet cells, microtubular abnormalities of the cilia, lesions of the apical cell membrane with loss of cilia and microvilli. These ultrastructural changes were not correlated with the above-mentioned signs of inflammation.