Peanut allergen extract

Peanut allergen extract is a standardized mixture of proteins derived from the peanut plant, Arachis hypogaea, containing key allergenic components such as Ara h 1, Ara h 2, and Ara h 3 [FDA, 2020]. It serves as the biological basis for oral immunotherapy (OIT), a treatment strategy designed to desensitize individuals with IgE-mediated peanut allergies [StatPearls, 2023]. The primary biological function of the extract in a therapeutic context is to modulate the patient's immune response, shifting it from a hypersensitive Th2-weighted state toward clinical tolerance [NIH, 2023]. This is achieved through the induction of regulatory T cells and the production of allergen-specific IgG4 antibodies, which compete with IgE for allergen binding [JACI, 2018]. In clinical practice, the extract is administered in escalating doses to increase the threshold of peanut protein required to trigger an allergic reaction [FDA, 2020]. While it does not cure the allergy, it significantly reduces the risk of severe systemic reactions, including anaphylaxis, resulting from accidental exposure [StatPearls, 2023]. However, the administration of peanut allergen extract carries inherent risks of triggering the very allergic symptoms it aims to treat, necessitating strict dosing protocols [FDA, 2020]. It is also associated with the development of eosinophilic esophagitis in a subset of patients [NIH, 2023]. Overall, it represents a critical advancement in managing food allergies by moving beyond simple avoidance to active immunological modification [JACI, 2018].

Other names

Arachis hypogaea allergenPeanut protein extractPeanut (Arachis hypogaea) allergen powder-dnfpAR101

Peanut allergen extract acts via oral immunotherapy (OIT) to induce immunological desensitization. By providing controlled, escalating exposure to peanut proteins (Ara h 1, 2, and 3), it promotes a shift from a Th2-mediated allergic response to a Th1/Treg-mediated tolerant state. This process is characterized by a decrease in allergen-specific IgE-mediated mast cell and basophil activation and a concomitant increase in allergen-specific IgG4 antibodies, which act as blocking antibodies to prevent IgE-allergen binding [FDA, 2020; StatPearls, 2023; JACI, 2018].