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/µL), 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 ΔFEV1/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.