Allergen-specific immunotherapy (AIT) (AIT)

The immune system's interaction with allergen epitopes is the fundamental driver of Type I hypersensitivity reactions, such as allergic rhinitis, asthma, and food allergies. Allergen epitopes are specific molecular regions on antigenic proteins that are recognized by the B-cell receptor (leading to IgE production) and the T-cell receptor (leading to Th2 cell activation). In a sensitized individual, the binding of these epitopes to IgE-coated mast cells and basophils triggers the release of inflammatory mediators like histamine and leukotrienes (Galli et al., 2008). Therapeutic intervention, known as allergen-specific immunotherapy (AIT), utilizes these epitopes to reprogram the immune system toward tolerance. By administering controlled, increasing doses of allergen epitopes, AIT induces the expansion of regulatory T-cells (Tregs) and the production of IgG4 'blocking' antibodies, which compete with IgE for epitope binding and suppress the allergic cascade (Akdis & Akdis, 2014). This process effectively shifts the immune response from a pro-inflammatory Th2 state to a regulated Th1 or Treg-mediated state, providing long-term relief from allergic symptoms even after treatment cessation (Durham & Penagos, 2016).

Other names

Allergen immunotherapyDesensitizationHyposensitizationEpitope-based immunotherapySpecific immunotherapy (SIT)Allergen-specific immune responsePeptide-based immunotherapy

Induction of immune tolerance by shifting the immune response from a Th2-dominated profile to a Th1/Treg-dominated profile, increasing the production of regulatory cytokines like IL-10 and TGF-beta, and stimulating the production of allergen-specific IgG4 'blocking' antibodies that compete with IgE for allergen binding (Akdis & Akdis, 2014; Durham & Penagos, 2016).