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.