Hydrogen Peroxide Generation by Eosinophils in Allergic Rhinitis

It was the aim to study the hydrogen peroxide (H 2 O 2 ) generation by eosinophils in allergic rhinitis caused by house dust which was examined in nasal secretion and peripheral blood. The concentration of H 2 O 2 in nasal secretions was increased after nasal challenge with house dust, and subsided gradually by the increase of peroxidase activity. The population of eosinophils and H 2 O 2 generation which was morphologically detected on the plasma membrane of eosinophils in nasal secretion, were increased with the release of eosinophil chemotactic activity after nasal challenge. Also, in peripheral blood, the number and phagocytic activity of eosinophils in extremely high density 1.102 g/ml were increased after nasal challenge. A high number of eosinophils was found in a density of 1.097 g/ml in the high IgE group, but showed less phagocytic activity than in the lower IgE group. Considering from these findings, H 2 O 2 generation by eosinophils appeared to be an important event in tissue injury and augmentation of allergic reaction.