Peanut-specific Immunoglobulin G (Peanut-specific IgG)

Peanut-specific Immunoglobulin G (IgG) refers to a class of antibodies produced by the immune system that specifically recognize and bind to proteins found in peanuts (Arachis hypogaea), such as Ara h 1, Ara h 2, and Ara h 3 (Santos & Lack, 2016). In the context of peanut allergy, these antibodies, particularly the IgG4 subclass, are primarily recognized for their role as "blocking antibodies" (Akdis & Akdis, 2014). They function by competing with peanut-specific IgE for binding sites on allergens, thereby preventing the cross-linking of IgE on the surface of mast cells and basophils, which would otherwise trigger an allergic reaction (Shamji & Durham, 2017). While not a traditional therapeutic target that drugs are designed to inhibit, the induction of peanut-specific IgG is a key objective and biomarker of success in allergen-specific immunotherapies, such as oral immunotherapy (OIT) (Vickery et al., 2013). Consequently, monitoring the levels of these antibodies, often in relation to IgE levels, helps clinicians assess a patient's progress toward desensitization or sustained unresponsiveness (Santos & Lack, 2016). Despite its protective associations, the presence of peanut-specific IgG alone is not a guarantee of clinical tolerance, and its precise role in the long-term management of peanut allergy remains a subject of active research (Akdis & Akdis, 2014).

Other names

Anti-peanut IgGArachis hypogaea-specific IgGPeanut-specific IgG4Peanut-specific immunoglobulin G4

Peanut-specific IgG is not a direct therapeutic target; instead, it acts as a competitive inhibitor of IgE-allergen binding, a process often induced by allergen-specific immunotherapy to promote desensitization.