Bronchiectasis: From targets to therapies

Bronchiectasis is a chronic obstructive airway disease characterized by abnormal bronchial dilatation and the accumulation of muco-purulent endoluminal secretions. Progressive lung function deterioration, frequent bouts of respiratory infection and daily productive cough negatively impact the lives of affected individuals. Multiple causal factors can initiate bronchiectasis; however, defects in host defenses represent a cardinal feature. The first line of airway defense against inhaled pathogens is mucociliary clearance. Systemic host defense defects, particularly those affecting opsonophagocytosis and killing of bacteria are equally essential to prevent bronchiectasis. Substantial evidence suggests that unopposed neutrophil protease activity in the airway lumen leads to the loss of bronchial elasticity and excessive accumulation of mucus. The focus of this review is on the advances in our understanding of pathogenic mechanisms that are bringing new targeted therapies for individuals suffering from the clinical manifestations of bronchiectasis.