Effect of inhaled budesonide on lung function and airway inflammation - Assessment by various inflammatory markers in mild asthma

In a double-blind, cross-over study, we examined the effect of inhaled bude sonide (800 mu g twice daily via Turbohaler) on lung function and various m arkers of airway inflammation including airway responsiveness to methacholi ne (PC20), exhaled nitric oxide (NO), eosinophils in induced sputum, bronch oalveolar lavage (BAL), and airway biopsies from 14 patients with mild asth ma needing beta(2)-agonist therapy only. After inhaled steroids, there was a significant increase in FEV1 and PC20, and reduction in exhaled NO. Eosin ophils in induced sputum and airway biopsy sections were also significantly decreased, although BAL eosinophil counts remained unchanged. At baseline, significant correlations were observed between exhaled NO and PC20 methach oline (r = 0.64 p < 0.05), exhaled NO and peak expiratory flow rate (PEFR) variability (r = 0.65, p < 0.05), sputum eosinophils and FEV1 (r = -0.63, p = 0.05), and sputum eosinophils and log PC20 methacholine (r = -0.67, p < 0.05). After treatment with inhaled steroids, there was a significant corre lation between eosinophils in biopsy sections, and BAL, with log PC20 metha choline. It is likely that these parameters represent different aspects of the inflammatory process, which are all inhibited by inhaled steroids.