In the context of immunopathology, which immunoglobulin is involved in mediating allergic responses?

The immunoglobulin that is primarily involved in mediating allergic responses is IgE. When an individual is exposed to an allergen, IgE is produced as a part of the immune response. This specific antibody binds to allergens and triggers the activation of mast cells and basophils, leading to the release of histamine and other chemicals responsible for the symptoms of an allergic reaction, such as hives, asthma, or anaphylaxis.

IgE's unique role in allergic responses distinguishes it from other immunoglobulins. IgG, for instance, is more involved in providing long-term immunity and is crucial in neutralizing pathogens and toxins. IgA primarily functions in mucosal immunity, protecting against pathogens entering through mucosal surfaces, and IgD plays a role in B cell activation but does not significantly influence allergic responses. This specificity of IgE highlights its critical role in the pathophysiology of allergic conditions.