Grass pollen allergen-specific immunoglobulin E and immunoglobulin G antibodies (sIgE/sIgG)

Grass pollen allergen-specific IgE and IgG antibodies are the primary immunological mediators and regulators of grass pollen allergy, also known as hay fever or seasonal allergic rhinitis (NIH, 2013; AAAAI, 2018). IgE antibodies specific to grass allergens, such as Phl p 1 and Phl p 5, bind to high-affinity FcεRI receptors on mast cells and basophils; upon subsequent exposure to grass pollen, allergen-induced cross-linking of these IgE molecules triggers the release of histamine and other inflammatory mediators (NIH, 2022). In contrast, allergen-specific IgG antibodies, particularly the IgG4 subclass, are induced by allergen-specific immunotherapy (AIT) and act as 'blocking antibodies' that compete with IgE for allergen binding, thereby preventing the allergic cascade (NIH, 2019; NIH, 2002). Therapeutic interventions such as sublingual (SLIT) and subcutaneous (SCIT) immunotherapy aim to modulate the levels of these antibodies, typically increasing the ratio of IgG4 to IgE to achieve clinical desensitization (JAMA, 2017; AAAAI, 2021). Additionally, monoclonal antibodies like omalizumab can target the IgE pool to reduce allergic sensitivity (AAAAI, 2024). Monitoring these antibody levels serves as a vital biomarker for diagnosing sensitization and evaluating the efficacy of immunotherapy in patients with allergic respiratory diseases (EMJ, 2022).

Other names

Grass pollen-specific antibodiesTimothy grass-specific IgE and IgGsIgE and sIgG4Grass pollen-specific IgE/IgG

Allergen-specific immunotherapy (AIT) induces a shift from a Th2-mediated IgE response to a Th1/Treg-mediated IgG4 response, where IgG4 acts as a blocking antibody that competes with IgE for allergen binding. Anti-IgE therapy (e.g., omalizumab) binds to the Fc region of IgE, preventing its interaction with FcεRI receptors on effector cells.