Immunoglobulin E specific for Fel d 1 (Fel d 1-specific IgE)

Immunoglobulin E (IgE) specific for Fel d 1 is a specialized antibody that plays a central role in the allergic response to domestic cats. Fel d 1, a secretoglobin protein produced in cat saliva and skin, is the primary allergen responsible for over 90% of cat-related sensitivities (Gronlund et al., 2010). In sensitized individuals, Fel d 1-specific IgE is produced by B cells and subsequently binds to high-affinity FcεRI receptors on the surface of mast cells and basophils (StatPearls, 2023). Upon re-exposure to the allergen, Fel d 1 cross-links these surface-bound IgE molecules, triggering the immediate release of inflammatory mediators like histamine and leukotrienes, which cause symptoms of allergic rhinitis and asthma (NIH, 2022). Therapeutic interventions such as omalizumab target the IgE molecule itself, sequestering it to prevent receptor binding and subsequent cellular activation (FDA, 2023). Additionally, allergen-specific immunotherapy (AIT) aims to modulate the immune system to reduce the production of these specific IgE antibodies in favor of protective IgG4 antibodies.

Other names

Anti-Fel d 1 IgECat allergen-specific IgEsIgE Fel d 1

Binding to the Cε3 domain of the IgE molecule, preventing its interaction with the high-affinity IgE receptor (FcεRI) on mast cells and basophils.