Extensive airway remodelling in severe COPD imparts resiliency to environmental stressors
Chronic obstructive pulmonary disease (COPD) is a highly prevalent chronic lung disease that is expected to become the third most common cause of death globally by 2030.1 It is characterised by extensive, detrimental structural and functional changes termed ‘remodelling’ in the airway epithelium in response to noxious inhaled contaminants. Cigarette smoke is traditionally considered the chief culprit, but environmental pollutants are now recognised as a critically important, if not as the major inhaled threat.2 The airway epithelium is a patchwork of luminal multiciliated and secretory cells and an underlying population of basal stem cells. Remodelling is evidenced by the expansion of secretory cells at the expense of multiciliated cells, which disrupts mucociliary clearance, a vital respiratory host defence mechanism.3 4 The resulting vicious cycles of infection, inflammation and injury fuel further remodelling phenotypes including diminished epithelial barrier and regenerative capaci