immunoglobulin E (IgE), one of the five classes of antibodies produced by the body. It is concentrated in the lungs, skin, and mucous membranes. It provides the primary defense against parasites, such as parasitic worms, but can also recognize allergens (such as pollen, dust mites). After binding with receptors on mast cells and basophils, it can release histamines and leukotrienes from these cells and cause anaphylactic hypersensitivity reactions characterized by wheal and flare. The normal concentration of IgE in serum is 0.01 to 0.04 mg/dL. Compare immunoglobulin A, immunoglobulin D, immunoglobulin G, immunoglobulin M.
