Human Immunoglobulin E (IgE) specific for Helianthus annuus pollen allergens (Hel a-sIgE)

Human Immunoglobulin E (IgE) specific for Helianthus annuus pollen allergens refers to the population of antibodies that mediate allergic sensitivity to sunflower pollen. These antibodies are produced by plasma cells following sensitization to specific sunflower proteins, most notably the pectate lyase Hel a 1 and the profilin Hel a 2 (WHO/IUIS Allergen Nomenclature Sub-Committee, 2024). Once synthesized, these IgE molecules circulate in the blood and bind to high-affinity FcεRI receptors on the surface of mast cells and basophils. Upon re-exposure to sunflower pollen, the allergens cross-link the receptor-bound IgE, triggering the degranulation of these effector cells and the release of inflammatory mediators such as histamine and leukotrienes (Galli et al., 2008). This physiological cascade results in the clinical symptoms of seasonal allergic rhinitis, conjunctivitis, and in some cases, bronchial asthma (Bousquet et al., 2020). Therapeutic strategies targeting these antibodies include the use of anti-IgE monoclonal antibodies like Omalizumab, which sequester free IgE to prevent cellular activation, and allergen-specific immunotherapy, which aims to desensitize the patient by modulating the underlying immune response (Akdis & Akdis, 2014).

Other names

Sunflower pollen-specific IgEAnti-Helianthus annuus IgEAnti-Hel a IgEHel a 1-specific IgE

Omalizumab binds to the Cε3 domain of free IgE, preventing its interaction with the high-affinity IgE receptor (FcεRI) on mast cells and basophils (FDA, 2023). Allergen-specific immunotherapy (AIT) induces immune tolerance by promoting the production of blocking IgG4 antibodies and regulatory T cells (Akdis & Akdis, 2014).