The Nose–Lung Axis in Chronic Obstructive Pulmonary Disease: An Emerging Interface for Clinical Endotyping, Biomarker Discovery, and Integrated Management

Chronic obstructive pulmonary disease (COPD) continues to be framed predominantly as a disorder of the lower airways, defined operationally by airflow limitation, and assessed through a combination of spirometry, symptom burden, and exacerbation history [...]