Immunoglobulin E specific for Phleum pratense allergen 2 (IgE anti-Phl p 2)

Immunoglobulin E (IgE) specific for Phleum pratense allergen 2 (Phl p 2) is a key mediator in the allergic response to Timothy grass pollen, one of the most common causes of seasonal hay fever and allergic asthma worldwide. Phl p 2 is a major allergen belonging to the expansin-like protein family, and specific IgE antibodies against it are found in a high percentage of grass pollen-allergic individuals (WHO/IUIS Allergen Nomenclature). When these IgE antibodies, bound to high-affinity receptors (FcεRI) on mast cells and basophils, encounter Phl p 2, they trigger the release of inflammatory mediators like histamine, leading to clinical symptoms of allergy (PubMed: 10474032). Therapeutic strategies targeting this pathway include the use of anti-IgE monoclonal antibodies like Omalizumab, which sequester free IgE to prevent cellular activation (StatPearls: NBK545184). Additionally, allergen-specific immunotherapy (AIT) aims to modify the immune system's response to Phl p 2 by inducing immunological tolerance, typically characterized by a decrease in specific IgE and an increase in protective IgG4 antibodies (PubMed: 16844895). Monitoring levels of Phl p 2-specific IgE is crucial for diagnosing Timothy grass allergy and assessing the efficacy of desensitization treatments.

Other names

Anti-Phl p 2 IgETimothy grass allergen Phl p 2-specific IgEsIgE Phl p 2Specific IgE to Phl p 2

Anti-IgE monoclonal antibodies like Omalizumab bind to the Fc region of circulating IgE, preventing it from docking with high-affinity FcεRI receptors on mast cells and basophils (StatPearls: NBK545184). Allergen-specific immunotherapy (AIT) involves controlled exposure to Phl p 2 to induce regulatory T cells and promote the production of allergen-specific IgG4, which acts as a blocking antibody to prevent IgE-allergen binding and subsequent degranulation (PubMed: 16844895).