Effects of fluticasone propionate on inflammatory cells in COPD: an ultrastructural examination of endobronchial biopsy tissue

Background: Inhaled corticosteroids (ICS) markedly reduce bronchial mucosal inflammation in asthma but whether they have an anti-inflammatory effect in airway tissue in chronic obstructive pulmonary disease (COPD) is unknown. Methods: A study of endobronchial biopsy samples was conducted as part of a double blind, placebo controlled, randomised trial of parallel design. Patients had mild to moderately severe COPD (FEV1 25–80% of predicted) and were given 3 months treatment with ICS, fluticasone propionate (FP; 500 μg twice daily, n=14) or placebo (n=10). Biopsy tissue taken at baseline and after treatment was examined by transmission electron microscopy to count the numbers of all ultrastructurally distinct inflammatory cells. Results: Compared with their baseline values, FP resulted in a significant decrease (on average 65%) in the numbers of mucosal mast cells (median 7.8 (range 1–33) v 2.8 (1–14), p