IgE - Definition and Overview

Immunoglobulin E (IgE) is an antibody from the gamma class of globulin blood proteins. It is the least abundant of the antibodies and is found in plasma, cerebrospinal fluid and tissues.

Its role in disease:

• It mediates type 1 hypersensitivity and hence plays a prominent role in allergy, asthma, eczema, allergic conjunctivitis, allergic rhinitis and the feared anaphylaxis.
• It is often elevated in patients with parasitic infections.

Like all immunoglobulins, it is secreted by plasma cells. IgE adheres to mast cells on a dedicated receptor (FcεRI). Contact of IgE with an epitope leads to activation and degranulation of the mast cell.