Allergy: enter igeA major advance in classical allergy - and one that helped to widen the rift with the unorthodox food allergists - was the discovery of immunoglobulin E, or IgE, in the 1960s. This type of immunoglobulin, or antibody, is the main villain in the classical allergic conditions. How it works will be considered in some detail in the next chapter, but it is worth describing briefly here. An antibody is a protein molecule made by the body to help combat disease-causing bacteria and viruses. The antibody binds to a specific target, known as its antigen. This target is usually a chemical located on the virus or bacterium, so the net result is that the antibody binds to the invader. The bound antibodies are rather like accusing fingers, pointing at the invading microbe - their presence rouses the body's defensive cells (the immune cells) to attack the microbe. What goes wrong in allergy is that the body makes IgE antibodies in response to an innocuous antigen, such as a food molecule. IgE antibodies are usually found on the surface of special immune cells known as mast cells, that occur in tissues throughout the body. If the IgE molecules on the surface of a mast cell bind to their specific antigen, they stimulate the mast cell to release several chemical messengers. The normal purpose of these chemicals is to organize a more effective immune response, but in sufficient quantities they can produce the damaging symptoms of allergy. The antigen that causes such a reaction {eg a food molecule) is known as an allergen. *9\180\8* Allergies «Online Pharmacy Without a Prescription» |