Biomarker Profiles in Asthma With High vs Low Airway Reversibility and Poor Disease Control

BACKGROUND: High bronchodilator reversibility in adult asthma is associated with distinct clinical characteristics. This analysis compares lung function, biomarker profiles, and disease control in patients with high reversibility (HR) and low reversibility (LR) asthma. METHODS: A retrospective analysis was performed with data from two completed clinical trials of similar design. Patients were divided into HR and LR subgroups based on their response to bronchodilators (HR = Delta FEV1 postbronchodilator >= 20%). Blood eosinophil count, serum IgE level, and fraction of exhaled nitric oxide concentration, biomarkers commonly used to stratify patients into T-helper (Th)-2-high vs Th2-low phenotypes, were measured in patients with not well controlled (1.5 <= Asthma Control Questionnaire [ACQ] <= 2.143) and very poorly controlled (ACQ > 2.143) disease. RESULTS: The majority of patients in the HR and LR subgroups displayed Th2-low biomarker profiles and very poor disease control. HR was more frequently associated with Th2-high biomarker profiles (40.1% vs 29.4%, P = .006), lower lung function (FEV1, 63.5 +/- 7.7% predicted vs 67.9 +/- 8.4% predicted; P < .001), and atopy (93.7% vs 86.5%, P = .005). CONCLUSIONS: HR is a physiologic indicator of reduced lung function and is more oft en associated with elevations in Th2 biomarkers than LR in moderate to severe asthma. However, the majority of patients with HR and LR asthma in this analysis had a Th2-low biomarker profile. Moreover, a Th2-high biomarker profile was not associated with worse disease control.