Allergen-Specific IgE Antibody

The protein of the blood is composed of albumin and globulins. One type of globulin is the group of gamma globulins, also called immunoglobulins or antibodies. Gamma globulins are produced by certain white blood cells known as B lymphocytes in response to stimulation by antigens. There are five types of immunoglobulins: IgA, IgD, IgE, IgG, and IgM. IgE is the antibody of allergies.
Testing for allergies to various substances can be done via skin testing, however, this can be uncomfortable for the patient and carries the risk of causing an allergic reaction, since allergens are actually introduced into the body. Another way to test for such allergies is the allergen-specific IgE antibody test. This test is also called the radioallergosorbent test, or RAST test, because it involves the use of fluorescent immunoassay to identify the specific allergens that are affecting the person. The specific antigens, or allergens, are bound to a carrier substance. If the person is allergic to a particular allergen, a specific IgE antibody in the person’s blood sample will react with the allergen.