Background: Basophil histamine release has been found to correlate with the presence and severity of allergic disease. However, it remains to be established whether airway response to antigen is related to basophil involvement and its release of histamine.
Objective: The purpose of this study was to investigate whether the intensity of airway response to an inhaled antigen challenge in allergic subjects is related to IgE-dependent peripheral blood basophil histamine release.
Methods: The response to segmental bronchoprovocation with antigen was examined in 34 subjects with allergic rhinitis. Bronchoalveolar lavage samples were obtained 5 minutes (immediate response) and 48 hours (late response) after allergen challenge. Peripheral blood maximal basophil histamine release (MBHR) in response to in vitro antigen stimulation was determined in each subject before segmental bronchoprovocation.
Results: Bronchoalveolar lavage samples obtained during immediate response showed an increase in histamine, whereas the late response was noted for a marked enhancement in airway cells, particularly eosinophils. Interestingly, a significant correlation (r = 0.73, p < 0.0001, Spearman Rank test) was noted between MBHR and intensity of bronchoalveolar lavage eosinophilia at 48 hours. Furthermore, subjects with high (> or = 20%) MBHR had significantly higher total cells and eosinophils in bronchoalveolar lavage fluid 48 hours after antigen segmental bronchoprovocation when compared with subjects with low (< 20%) MBHR.
Conclusion: Our data suggest that the intensity of airway eosinophilia in response to antigen challenge is correlated with the magnitude of basophil mediator release in allergic subjects.