Airway basophils are increased and correlated with eosinophilic inflammtaion in asthma and COPD

Background: Though basophils have been considered allergy-related cells, the impact of these cells on human diseases are not well defined. Objectives: The aim of this study is to evaluate the airway basophils in two representative obstructive airway diseases, asthma and COPD. Method: Fifty-two sputum samples (normal: n=3, asthma: n=14, COPD: n=35) were analyzed through a multicolor flow cytometer. Basophils were determined as CD45 + FceRI hi SIRP-α lo c-kit - cells (Wakahara, K. et al. Blood 2012; 120: 4761-71). The correlations between sputum basophils and other inflammatory cells, eosinophil and neutrophil counts in blood and IgE levels were examined. Results: Basophils were detectable in sputum of asthma and COPD patients through a flow cytometer. The percentages of basophils were significantly correlated with those of eosinophils but not with those of neutrophils. Conclusion: Airway basophils were increased in both asthma and COPD and related with eosinophilic inflammations. These findings suggest basophils could be new targets for diagnosis and therapy of asthma and COPD.