MAST-CELLS IN THE AIRWAY LUMEN AND BRONCHIAL-MUCOSA OF PATIENTS WITH CHRONIC-BRONCHITIS

In order to evaluate the degree of mast cell infiltration and determin e their granulation state in the airways of patients with chronic bron chitis, bronchoscopy was performed in 25 chronic bronchitis subjects ( 10 smokers and 15 ex-smokers) with mucoid sputum production and in sev en normal nonsmoking control subjects. Bronchoalveolar lavage and bron chial biopsies were examined using histochemical techniques. Subjects with chronic bronchitis had higher numbers of mast cells both in the e pithelium (1.22 +/- 1 versus 0.22 +/- 0.2 mast cells per mm) and in th e bronchial glands (137.4 +/- 37.9 versus 38 +/- 5.1 mast cells per mm (2)) than did control subjects (p < 0.01 and p < 0.001, respectively), whereas the numbers of mast cells in bronchoalveolar ravage (0.21 +/- 0.1 versus 0.18 +/- 0.1 mast cells percentage, nonsignificant [NS]) a nd in the lamina propria (87.5 +/- 66.4 verses 87.2 +/- 61.8 mast cell s per mm(2), NS) were similar in the two groups. In the smoking group of bronchitics an increase in mast cell numbers was observed in epithe lium (1.6 +/- 1.3 versus 0.95 +/- 0.7 mast cells per mm, NS), in lamin a propria (112.2 +/- 86.5 versus 71.7 +/- 45.7 mast cells per mm(2)), and in BAL (0.26 +/- 0.21 versus 0.16 +/- 0.17 mast cell percentage of total cells, NS) in comparison with the ex-smoker's group of bronchit ics. There was a significant increase in the number of partially degra nulated mast cells in bronchial glands of subjects with chronic bronch itis (23.8 +/- 19.7 versus zero percent of mast cell number, p < 0.05) , whereas the numbers of granulated, partially degranulated, and degra nulated mast cells were similar in the epithelium and the lamina propr ia. In conclusion, the present study provides evidence of mast cell in filtration and degranulation in the bronchial glands of patients with chronic bronchitis, supporting mast cell involvement in pathogenesis o f airway hypersecretion.