Distribution of T2 markers in real-life patients with asthma, COPD and asthma+COPD from the BREATHE study

Targeted therapies for severe T2-high asthma emphasize the need to investigate the expression of different T2 markers in real-life patients. We aimed to assess the co-expression of T2 markers in patients with asthma, COPD and asthma+COPD. BREATHE is a large real-life study assessing biomarkers and disease mechanisms in a real-life population of asthma and COPD patients. Eosinophilia was defined as blood eosinophils >0.3x109 cells/L and/or sputum eosinophils ≥3%, elevated FeNO as ≥25 ppb, and elevated IgE as ≥100 IU/ml. 63% of asthma patients had ≥1 increased T2 biomarker: 25% had increased IgE, 33% had elevated FeNO and 42% had eosinophilia. Among COPD patients, 53% had ≥1 increased T2 marker: 19% had increased IgE, 15% had elevated FeNO and 36% had eosinophilia. In asthma+COPD patients, 63% had ≥1 increased T2 biomarker: 22% had increased IgE, 23% had elevated FeNO and 47% had eosinophilia. Blood and sputum eosinophilia were co-expressed in 19.6% of asthma, 13.3% of COPD and 20.3% of asthma+COPD patients. COPD and asthma+COPD patients were more likely to have isolated eosinophilia (42% and 41%) compared to asthma patients (25%) (figure 1a-c). The prevalence of at least one elevated T2 marker was comparable between asthma, COPD and asthma+COPD, with isolated eosinophilia being most common in COPD and asthma+COPD. This supports the existence of different subtypes of T2 asthma, COPD and asthma+COPD.