The dual role of small EVs in asthma and chronic obstructive pulmonary disease: from pathogenesis to clinical translation

Asthma and chronic obstructive pulmonary disease (COPD) are leading causes of chronic respiratory morbidity, yet current therapies fail to halt airway remodeling or disease progression. Small extracellular vesicles (small EVs), a nanoscale subset of extracellular vesicles that includes exosomes, have emerged as key mediators of intercellular communication in the lung, transferring proteins, lipids and nucleic acids to modulate inflammation, immunity and tissue repair. Their cargo reflects donor cell state and can be sampled from biofluids, suggesting their potential as liquid-biopsy biomarkers and therapeutic vehicles. Notably, small EVs exert context-dependent bidirectional effects in asthma and COPD, either exacerbating airway inflammation and remodeling or suppressing immune responses and promoting repair. This review synthesizes the biological functions of small EVs in these diseases, dissects mechanisms underlying their dual roles, and evaluates their translational potential as biomarkers and candidate therapeutic strategies, while outlining critical challenges in isolation, standardization and clinical validation.