Immunoglobulin E specific for Felis domesticus allergen 1 (Fel d 1-specific IgE) (Fel d 1-specific IgE)

Immunoglobulin E (IgE) specific for Felis domesticus allergen 1 (Fel d 1) is the primary molecular mediator of cat-induced allergic reactions in sensitized individuals (Bonnet et al., 2018). These antibodies are produced by B cells and plasma cells in response to Fel d 1, a secretoglobin protein found in cat saliva and sebaceous glands (Grönlund et al., 2010). Once produced, these IgE molecules circulate and bind to high-affinity FcεRI receptors on the surface of mast cells and basophils (Gould & Sutton, 2008). Upon subsequent exposure to cat dander, the Fel d 1 allergen cross-links the surface-bound IgE, triggering the immediate release of inflammatory mediators like histamine and leukotrienes. This cascade leads to clinical symptoms such as allergic rhinitis, conjunctivitis, and exacerbations of allergic asthma. Therapeutic strategies targeting these antibodies include the use of anti-IgE monoclonal antibodies like Omalizumab, which bind to the Fc region of free IgE to prevent its interaction with cellular receptors (Incorvaia et al., 2014). Additionally, novel approaches such as allergen-specific IgG antibodies (e.g., REGN1908/1909) aim to compete with IgE for allergen binding, effectively shielding the sensitized cells from activation (Orengo et al., 2018).

Other names

Anti-Fel d 1 IgECat allergen-specific IgEsIgE to Fel d 1Felis domesticus allergen 1-specific immunoglobulin E

Binding to the Cε3 domain of the IgE molecule, which overlaps with the binding site for the high-affinity FcεRI receptor, thereby preventing IgE from docking onto mast cells and basophils and neutralizing circulating IgE.