Purpose of the review We have attempted to bring together recent findings, mainly from airway endobronchial biopsies, on the structural changes that constitute ’remodelling’ in airway disease, with a particular focus on asthma. We have tried to put this into the context of classic studies on the asthma pathological phenotype. Having described these basic changes, we have then given an update on recent studies investigating the effects of corticosteroid medication on the different manifestations of remodelled airways.

Recent findings The effects of corticosteroid on airway remodelling seem to vary a great deal; some aspects are steroid responsive while others are not, or less so. It is likely that different manifestations of remodelling require different doses and timescales for treatment to be effective.

Summary Further longitudinal interventional studies are required, with multiple airway sampling times, to fully elucidate the full potential for corticosteroids to benefit remodelling of the airways in chronic inflammatory diseases. There needs to be more attention to pathophysiological and clinical correlations in such studies. It is likely that even when used optimally corticosteroids will have limited efficacy overall in this aspect of asthma pathogenesis. The search is on for newer and better treatments.

Abbreviations ASM: airway smooth muscle; BAL: bronchoalveolar lavage; BHR: bronchial hyperresponsiveness; BOS: bronchiolitis obliterans syndrome; EGF: epidermal growth factor; ICS: inhaled corticosteroid; RBM: reticular basement membrane; VEGF: vascular endothelial growth factor.