What role does IgE play in the immune system?

IgE, or Immunoglobulin E, plays a crucial role in the immune system by mediating allergic reactions and triggering the release of histamines from mast cells and basophils. When an individual is exposed to an allergen, IgE binds to the allergen and facilitates the activation of these immune cells. This activation results in the release of various mediators, including histamines, which contribute to the symptoms of allergic reactions, such as itching, swelling, and bronchoconstriction.

The unique function of IgE in relation to allergic responses is what differentiates it from other classes of immunoglobulins like IgG, which primarily neutralizes pathogens, or IgM, which is involved in complement activation. While IgE does provide some level of defense against parasitic infections, its most prominent role is linked to hypersensitivity reactions and the immediate immune response triggered by allergens.