Allergen-specific immunoglobulin G (sIgG) (sIgG)

Allergen-specific immunoglobulin G (IgG) antibodies, particularly the IgG4 subclass, are critical effector molecules produced by the immune system in response to allergen immunotherapy (AIT). These antibodies function as \blocking antibodies\ by competing with allergen-specific IgE for binding sites on allergens, thereby preventing the cross-linking of IgE on mast cells and basophils (PMID: 24388011). This competition effectively inhibits the release of inflammatory mediators such as histamine, which drive allergic symptoms. Furthermore, allergen-specific IgG can engage the inhibitory receptor FcγRIIb, providing a negative signal that suppresses IgE-mediated cell activation and B-cell production of IgE (PMID: 21463118). While not a traditional therapeutic target for inhibition, the induction of high-affinity allergen-specific IgG is the primary goal of desensitization therapies for conditions like allergic rhinitis, asthma, and venom hypersensitivity (PMID: 28888249). Consequently, serum levels of these antibodies, especially the IgG4/IgE ratio, serve as vital biomarkers for monitoring the clinical efficacy and immunological progress of patients undergoing immunotherapy (PMID: 30445140).

Other names

Allergen-specific IgGsIgG4Blocking antibodiesAntigen-specific IgG

Induction of blocking antibodies to compete with IgE for allergen binding and engagement of inhibitory FcγRIIb receptors (PMID: 24388011)