Clinical Characteristics of T2-Low and T2-High Asthma-Chronic Obstructive Pulmonary Disease Overlap: Findings From COREA Cohort

Purpose: Despite the emerging biologics, biomarkers and treatment options for asthma- chronic obstructive pulmonary disease (COPD) overlap (ACO) are still limited, requiring further research. Methods: We enrolled 378 ACO patients from a multicenter real-world asthma cohort in Korea and compared the clinical characteristics, lung function, and exacerbation between type 2 (T2)-high and T2-low groups. We used the following comparisons: 1) low vs. high immunoglobulin E (IgE) group (>= 100 IU/mL), 2) non-atopy vs. atopy group (sensitized to aeroallergen), 3) low vs. high blood eosinophil group (>= 150/mu L), and 4) low vs. high sputum eosinophil group (>= 2%). Results: The high sputum eosinophil ACO group (n = 37) showed significantly lower pre- and post-bronchodilator (BD) forced expiratory volume in 1 second (FEV1) and FEV1/forced vital capacity (FVC) (45.7% +/- 15.8% vs . 55.9% +/- 16.2%, P = 0.016; 1.3 +/- 0.6 L vs . 1.6 +/- 0.5 L, P = 0.013 for pre-BD FEV1; 0.53 +/- 0.1 vs . 0.59 +/- 0.1, P = 0.018 for post-BD FEV1/FVC) than the low sputum eosinophil ACO group (n = 25). When examining changes in lung function at the 3-month follow-up, there were significant decreases in FEV1 in the high IgE ACO group (n = 104; -11.4% +/- 16.7% vs . -4.4% +/- 9.2%, P = 0.023) and Delta FEV1/FVC in the high sputum eosinophil ACO group (-0.049 +/- 0.063 vs . -0.004 +/- 0.064, P = 0.049) than in the low IgE ACO group (n = 44) and in the low sputum eosinophil ACO group, respectively. The risk of asthma exacerbation was significantly higher in the atopic ACO group (odds ratio, 4.2; 95% confidence interval, 1.0-17.4; P = 0.049) in the adjusted model. Conclusions: Since ACOs with T2-high profiles may have lower lung function and more frequent exacerbations, T2-high specific therapies, such as biologics, should be actively considered in T2-high ACO patients.