The role of eosinophila in the allergic reaction : Morphological changes of reactive eosinophils and immunoglobulin (G&E) receptors

Eosinophils were isolated from peripheral blood of healthy individuals, asthmatic subjects and patients with PIE syndrome using discontinuous Percoll gradients. Morphological changes of eosinophils stimulated with anti-IgG, anti-IgE and Cal were observed byu the direct count method. Furthermore, the number of immunoglobulin receptors on eosinophils was evaluared by SEM using anti-IgG and anti-IgE linked carboxylate modified latex particles. Eosinophil reactivity after these stimuli was significantly elevated compared to controls. Reactivity was dependent on calcium ions, but FMLP did not affect the reactivity. IgE as well as IgG receptors were significantly expressed on the surface of eosinophils. A positive correlation between the appearance of reactive eosinophils and the expression of these im-munoglobulin receptors was recognized. Correlation in patients with bronchial asthma or PIE syndrome was significantly higher than that in healthy individuals. The appearance of reactive eosinophils after stimulation with anti-IgG was remarkably higher than that after anti-IgE stimulation. The expression of IgG receptore was also higher than that of IgE receptors. These results suggest that obsarving morphological changes in eosinophils may be useful for analyzing the pathogenesis of allergic diseases