Anti-IgE antibodies react with the IgE isotype of human immunoglobulins. IgE is the shortest-lived immunoglobulin with a half-life of two days in serum. IgE plays an important role in allergy. It is especially associated with type 1 hypersensitivity, where IgE shows high-affinity binding to Fc receptors expressed on the surface of mast cells. Antigen binding to Fc receptor–bound IgE upon re-exposure to specific allergens results in degranulation and the release of a variety of mediators, such as histamine and cytokines.
IgE has two main receptors: the high-affinity receptor FcεRI, which is expressed only on mast cells and basophils, and the low-affinity receptor FcεRII (CD23), which is expressed on B cells.
This pure – functional grade antibody is suited for cell culture functional assays, for example, blocking of receptor-ligand binding.