Safety and cellular assessment of bronchial brushing in airway diseases

Bronchial brushing is a useful method for morphological and functional studies of bronchial epithelial cells (BECs) in various diseases. This technique has been found to be generally safe, but its safety in asthma and chronic bronchitis has not been fully assessed. The purpose of this study was to determine 1. whether bronchial brushing is a safe method in asthmatic and chronic bronchitis patients of differing severity and 2. to characterize the BECs obtained in terms of number, viability and purity. We evaluated 25 asthmatics of variable severity, 19 chronic bronchitis patients and 26 normal volunteers. Bronchoscopy and bronchial brushing were performed in a standardized manner by the same investigator. Safety was assessed by clinical follow-up of all subjects; continuous monitoring of arterial oxygen saturation during the procedure with a digital oximeter was carried out in a subsample of subjects. No complications were observed clinically during the procedure. There was a minimal fall in arterial oxygen saturation without a significant difference between the three groups of subjects. A consistent number of BECs was recovered and their viability, assessed by the trypan blue exclusion test, in asthmatics and chronic bronchitis patients was significantly lower than in controls (P<0.05). Bronchial brushing is well tolerated and may be a valuable method of obtaining BECs in asthmatic and chronic bronchitis patients.