Immunoglobulin E

Immunoglobulin E (reaginic antibody) is normally present in very low concentrations, although elevated levels are seen in atopic disease and in a number of other disorders. IgE antibody is made up of the basic four-chain structure. Mast cells and basophils have high-affinity receptors for the Fc region of IgE (FceRI). IL-4 is primarily responsible for the promotion of IgE isotype switching. The bridging of two IgE molecules by antigen results in the release of inflammatory mediators that characterize the immediate hypersensitivity response.

A new therapy for allergic disease and asthma consists of an anti-IgE antibody. This antibody has been engineered to bind only to the free, circulating IgE, not receptor-bound IgE. Thus, it does not initiate mast cell activation or degranulation by IgE receptor cross-linking