At the Root: Defining and Halting Progression of Early Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disorder with varying presentations and progression, but limited disease-modifying therapies. Trajectories of lung function decline in COPD differ significantly between individuals, with differences detectable in young adulthood. “Early disease” (initial manifestations in young individuals) should be distinguished from “late mild disease” (disease of mild severity in older individuals potentially present for decades). For research purposes, we propose an operational definition of early COPD: ever-smokers (≥10 pack-years) younger than 50 years with any of these abnormalities: (1) FEV1/FVC< lower limit of normal; (2) compatible CT abnormalities (airway abnormality and/or emphysema); or (3) FEV1 decline (≥60 mL/year). Biological underpinnings of early COPD are quite complex. Recent evidence implies that cigarette smoke-exposure induces sequential, stereotypical changes in distal airways, initially without inflammatory cell infiltration. Epitheli...