Immunoglobulin E (
IgE) is a type of antibody that has been found only in mammals. IgE is synthesised by plasma cells. Monomers of IgE consist of two heavy chains and two light chains, with the Īµ chain containing four Ig-like constant domains (CĪµ1āCĪµ4). IgE is thought to be an important part of the immune response against infection by certain parasitic worms, including
Schistosoma mansoni,
Trichinella spiralis, and
Fasciola hepatica. IgE is also utilized during immune defense against certain protozoan parasites such as
Plasmodium falciparum. IgE may have evolved as a defense to protect against venoms.