Changes in airway inflammation, remodelling and PD20 following inhaled corticosteroid treatment are not temporally concordant

Introduction. There have been direct calls for studies evaluating "the relationship of airway inflammation to airway remodelling, lung function and BHR" (Pedersen S. AJRCCM. 2000; 161 : pp S182-185). Current asthma guidelines rely on lung function and symptoms in management decisions. Methods. In a prospective, double blind study 33 steroid naïve, symptomatic asthmatics were randomised to receive FP 750μg bd or identical placebo. We obtained airway biopsies and 3x60 mL BAL at time zero, 3 and 12 months. 2μm glycol methacrylate embedded sections were stained for collagen I for assessment of reticular basement membrane thickness (rbm) using image analysis (Image Pro Plus). In addition BAL differential cell counts and PD20 FEV1.0 to methacholine (BHR) were assessed at each time point. Results. Mean (s.d) rbm was increased in asthmatics vs normals (9.1±2.2 vs 7.7±1.μm,p=0.003), as were % BAL eosinophils (2.9±4.1 vs 1.0±1.62, p=0.011) and mast cells (0.13±0.13 vs 0.03±0.04, p6.4)**,∧ 1.3±1.7**,# 0.06±.06**# **