Transepithelial potential difference in the bronchial system of children with chronic bronchitis and bronchial asthma.

In 45 children with chronic non-specific respiratory diseases (CNSRD), 18 with bronchial asthma and 27 with relapsing or chronic bronchitis, the transepithelial potential difference (tpd) was measured in the tracheobronchial system (bronchoscopy under general anaesthesia). The statistical variation in the tpds was highly significant. In asthmatics with significant eosinophilia in the bronchial secretions of the main bronchus we found a tpd of 26.5 (+/- 8.5) mV and in bronchitics a tpd of 18.2 (+/- 6.3) mV. This suggests that the presence or absence of eosinophils in the secretions, the products of intermediate cell metabolism or different pathogenetic processes, could be responsible for the variety of change in the tpd measured in the respiratory tract.