IgE-expressing memory B cells and plasmablasts are increased in blood of children with asthma, food allergy, and atopic dermatitis.

Despite the critical role of soluble IgE in the pathology of IgE-mediated allergic disease, little is known about abnormalities in the memory B cells and plasma cells that produce IgE in allergic patients. We here applied a flow cytometric approach to cross-sectionally study blood IgE+ memory B cells and plasmablasts in 149 children with atopic dermatitis, food allergy, and/or asthma and correlated these to helper T(h)2 cells and eosinophils. Children with allergic disease had increased numbers of IgE+CD27- and IgE+CD27+ memory B cells and IgE+ plasmablasts, as well as increased numbers of eosinophils and Th2 cells. IgE+ plasmablast numbers correlated positively with Th2 cell numbers. These findings open new possibilities for diagnosis and monitoring of treatment in patients with allergic diseases.