Immunoglobulin E and Immunoglobulin G4 (IgE and IgG4) (IgE/IgG4)

Immunoglobulin E (IgE) and Immunoglobulin G4 (IgG4) are critical components of the immune system's response to dog allergens, such as Can f 1 through Can f 6 [1, 2]. In sensitized individuals, dog-specific IgE binds to high-affinity FcεRI receptors on mast cells and basophils; subsequent allergen exposure causes IgE cross-linking and the release of inflammatory mediators like histamine, leading to allergic rhinitis, asthma, or dermatitis [1, 3]. IgG4 serves a counter-regulatory role, often increasing during successful allergen immunotherapy (AIT). It acts as a "blocking antibody" by competing with IgE for allergen binding sites and by co-aggregating with the inhibitory receptor FcγRIIb, which suppresses cell activation [4, 5]. Therapeutic interventions target this system either by depleting free IgE using monoclonal antibodies like Omalizumab or by inducing allergen-specific IgG4 through controlled exposure to dog allergen extracts [3, 6]. Monitoring the balance between these two antibody classes, often expressed as the sIgE/sIgG4 ratio, is essential for evaluating clinical sensitivity and the progress of desensitization therapies [1, 4].

Other names

Dog allergen-specific antibodiesCan f-specific IgE and IgG4Allergen-specific immunoglobulinsBlocking antibodies (IgG4)

Neutralization of free IgE to prevent binding to high-affinity FcεRI receptors; induction of allergen-specific IgG4 to compete for allergen binding and signal through inhibitory FcγRIIb receptors.