The Chronic Obstructive Pulmonary Disease (COPD)-Bronchiectasis Overlap Syndrome: Does My COPD Patient Have Bronchiectasis on Computed Tomography? "Frankly, My Dear, I Don't Give a Damn!"

Metersky and Dransfield discuss the chronic obstructive pulmonary disease (COPD)-bronchiectasis overlap syndrome. From a pathophysiologic standpoint, bronchiectasis and COPD are quite similar. Neutrophilic inflammation, including neutrophil extracellular traps, is an important driver of bronchiectasis outcomes, even in those with the eosinophilic phenotype. Neutrophil elastase (NE) has numerous deleterious effects, including epithelial damage, mucus hypersecretion, and impaired ciliary function. In bronchiectasis, NE levels correlate with exacerbation frequency and lung function decline.