Airway remodelling: the future

The research of structural changes in airway diseases is relatively recent compared with studies on physiological or inflammatory features. In airway diseases such as asthma and chronic obstructive pulmonary disease (COPD), structural alterations have been observed, such as: epithelial desquamation or hyperplasia; increases in smooth muscle mass; angiogenesis; increases in subepithelial collagen deposition, proteoglycans and elastin content; cartilage changes; and goblet cell and glandular hyperplasia, in addition to increased airway wall thickening 1. During the past months, the European Respiratory Journal has published a series on airway remodelling in order to review the state of knowledge in this increasingly important domain 2–6. We learnt from this series that airway remodelling is by no means a single entity. It is a complex and dynamic process with multiple components, evolving differently in various conditions, according to the type and extent of the structural responses to inflammatory or physical stimuli, probably under genetic influences modulating host response to the latter. The various in vitro and animal models developed to study the pathways involved in the changes in the bronchial structure induced by airways allergic reactions or other stimuli confirm this vast heterogeneity. The possible clinical significance of these structural changes and the effects of treatment are even more diverse. Hence, at this stage we will need to further elaborate on the main challenges for research in this field in order to help better understand the mechanisms of airway remodelling and to decide if, how and when to intervene on this process. Some of the key questions on airway remodelling are itemised in table 1⇓. Here are some of what we consider to be the vital remaining domains of research in this field. View this table: Table 1— Remaining questions on airway remodelling ### What is the time-course of the various remodelling changes? Animal models and studies of groups such as asymptomatic subjects with …