Effects of inhaled budesonide on airway inflammation,reticular basement membrane thickness and bronchial hyperresponsiveness in asthma

Abstract

Objective To study the relationships between airway inflammation,reticular basement membrane (RBM) thickness and bronchial hyperresponsiveness (BHR) before and after treatment with inhaled corticosteroids (ICS) in patients with asthma.Methods Twenty-eight patients with asthma (asthma group) were treated with inhaled budesonide (200 μg,twice a day for 12 months).Lung function,bronchoalveolar lavage (BAL) fluid and airway biopsy pathology were carried out before and after treatment.And 10 patients without asthma were acted as control group.Results BAL fluid eosinophils,epithelial cell and mast cell proportions before treatment in asthma group were significantly higher than those in control group [asthma group:(1.60 ±0.11)％,(2.50 ±0.29)％,(0.1100 ±0.0100)％ ;control group:(0.50 ±0.02)％,(1.20 ±0.08)％,(0.0200 ±0.0001)％,P ＜0.01].RBM and smooth muscle thickness were increased in asthma group than those in control group [ asthma group:( 14.25 ± 2.15 ),(0.36 ± 0.01 ) μ m;control group:(4.45 ± 1.22),(0.20 ± 0.01 ) μ m,P ＜ 0.01 ].BAL fluid eosinophils,epithelial cell and mast cell proportions,RBM and smooth muscle thickness decreased after treatment in asthma group [ (0.80 ±0.04)％,(1.60 ±0.07)％,(0.0500 ±0.0020)％,(6.18 ± 1.30) μm,(0.26 ±0.02) μm,P ＜0.01].RBM thickness was negative correlation with methacholine provoking dose which made forced expired volume in one second reduce by 20％ (r =-0.672,P ＜ 0.01 ).Conclusions Airway inflammation,RBM thickness and BHR in patients with asthma are interrelated and improved with ICS.The results of this study support the need for early and long treatment with ICS. Key words: Asthma; Basilar membrane; Bronchial hyperreactivity