T follicular helper cells in IgE-mediated pathologies.

T follicular helper (Tfh) cells help orchestrate optimal humoral immunity by helping B cells to produce affinity-matured, class-switched antibodies in germinal centers. Recent studies have unveiled the complexity and heterogeneity in Tfh cell populations, particularly with respect to their cytokine production. These distinct Tfh cell subsets help tune the class, magnitude and quality of the immunoglobulins produced by B cells, thus shaping the course of humoral responses. The Tfh cell-B cell axis-dependent antibody production is mostly beneficial, but at times can go awry and result in the generation of pathologic antibodies that can harm the host. While IgE class of antibodies are infamous for their detrimental role in allergic diseases, emerging evidence is indicative of their pathologic roles in other dysregulated immune states. Here, we discuss the role of Tfh cell subsets in the regulation of pathologic IgE production in allergies and other immunopathologic conditions.