House dust mite allergen-specific Immunoglobulin G4 (HDM-sIgG4)

House dust mite (HDM) allergen-specific IgG4 antibodies are a specialized subclass of immunoglobulins produced by the immune system in response to allergen immunotherapy (AIT) for Dermatophagoides species (Shamji & Durham, 2017). These antibodies play a critical role in the development of peripheral immune tolerance by acting as blocking antibodies that compete with allergen-specific IgE for binding to HDM allergens like Der p 1 and Der p 2 (Akdis & Akdis, 2014). By sequestering allergens, IgG4 prevents the cross-linking of IgE on the surface of mast cells and basophils, thereby inhibiting the release of inflammatory mediators such as histamine and leukotrienes (Flicker & Valenta, 2003). Furthermore, IgG4 can engage the inhibitory receptor FcγRIIb on B cells and other immune cells, providing an additional layer of immune suppression (James & Till, 2016). The induction of high levels of HDM-specific IgG4 is considered a primary mechanism of action for both subcutaneous (SCIT) and sublingual (SLIT) immunotherapies (Zuo et al., 2020). Consequently, these antibodies serve as essential biomarkers for monitoring the immunological shift from a Th2-driven allergic response to a more tolerant state during treatment (Nouri-Aria et al., 2004).

Other names

Dermatophagoides-specific IgG4Blocking antibodiesHDM-specific IgG4Allergen-specific IgG4Antigen-specific IgG4

Induction of B cell class switching to IgG4 via IL-10 producing regulatory T cells; these antibodies then compete with IgE for allergen binding, preventing mast cell activation.