The German Severe Asthma Registry and Type 2-high and Type 2-low asthma phenotypes

Targeted therapy is a relatively new treatment option for patients with severe asthma. Thus, precise phenotyping of this patient population is becoming more and more important. Type 2-driven asthma is characterized by the release of typical cytokines such as IL-4, IL-5 and IL-13. Based on the degree of Type2-inflammation Type2-high and Type 2-low phenotypes have been described which may show differential responses to available therapies. The frequency of both phenotypes was evaluated in patients in the German Severe Asthma Registry (1056 patients, 47.0±17.9 years (57% female), FEV1 2.03±0.83 L (66.8±22.8%) with 4.0±4.2 exacerbations in the previous year, 27.1% of patients treated with omalizumab and 6.8% with anti-IL-5 antibodies) by characterization of atopic status (positive skin prick test/specific IgE) as well as the Type 2 biomarkers blood eosinophils and exhaled nitric oxide (FeNO). For 396 patients information on all biomarkers were available. Only 1.8% (n=4) of patients who were currently not on oral corticosteroids (OCS) fulfilled the GINA criteria for Type 2-low asthma (no atopy, blood eosinophils 150/µl and 67.4% had FeNO levels > 25 ppb, thus demonstrating a Type-2 high pattern. Type 2-high asthma is the predominant phenotype among patients with severe asthma.