Type 2 Inflammatory Phenotypes in Chronic Obstructive Pulmonary Disease and Asthma: Similarities and Differences

BACKGROUND: Asthma and chronic obstructive pulmonary disease (COPD) - two common airway diseases - have drawn greater attention lately because of their increasing occurrence and mortality rates. The main inflammatory types - type 2 and non-type 2, which include type 1 and type 3 inflammation - are distinguished by the presence of discrete immune cells, that coordinate the recruitment and activation of inflammatory cells, resulting in various pathological presentations, clinical symptoms, therapeutic responses, and prognoses. Despite significant differences, COPD and asthma share many inflammatory commonalities. In recent years, the type 2 inflammatory phenotype in COPD has steadily emerged as the focus of COPD research. Understanding the differences between COPD and asthma with type 2 inflammatory phenotypes is critical for designing individualized treatment strategies. METHODS AND RESULTS: This review systematically searched for Chinese and English literature on COPD and asthma in the field of type 2 inflammation, and conducted a comprehensive review and analysis of the relevant content. It explored the similarities and differences between type 2 inflammatory phenotypes in COPD and asthma, with particular emphasis on their inflammatory mechanisms, clinical features, biomarkers, therapeutic targets, and treatment responses. CONCLUSION: This review investigates the similarities and differences between type 2 inflammatory phenotypes in COPD and asthma, with the aim of better addressing their diversities, gain deeper insights into their underlying cellular and molecular mechanisms, develop novel therapies in unmet areas, explore more effective treatment directions, reduce the disease burden, and enhance patient outcomes.