IgE super(+) cells in the peripheral blood of atopic, nonatopic, and bee venom-hypersensitive individuals exhibit the phenotype of highly differentiated B cells

We have analyzed IgE super(+) cells in peripheral blood of atopic donors, donors hypersensitive to bee venom, and nonatopic control donors with two- and three-color flow cytometry. Although the percentage of IgE super(+) cells varied among these groups, the overall phenotypic patterns were similar. Most IgE super(+) cells do not display typical B-cell markers, such as CD19, CD20, and CD21. A significant proportion of these cells strain for CD38, indicating that they are more differentiated. IgE super(+) cells express Fc gamma RII and CD45RO, an isoform associated with an advanced level of differentiation. The majority of IgE super(+) cells do not coexpress other surface immunoglobulin isotypes. In the case of bee venom-hypersensitive donors, we have been able to identify a small population of IgE super(+) cells with a specificity for phospholipase A2, a major immunogenic component of bee venom. The phospholipase A2 super(+) cells display a phenotype similar to that of the IgE super(+) cells.