Immunoglobulin E specific to cat allergens (Cat-specific IgE)

Immunoglobulin E (IgE) specific to cat allergens, particularly the major secretoglobin Fel d 1, is the central mediator of cat-induced allergic disease. In sensitized individuals, B cells produce these specific IgE antibodies, which then bind to high-affinity FcεRI receptors on the surface of mast cells and basophils (Bonnet et al., 2018, Allergy, Asthma & Clinical Immunology). Upon subsequent exposure to cat dander, the allergens cross-link the surface-bound IgE, triggering the immediate release of histamine, leukotrienes, and cytokines that cause symptoms ranging from rhinoconjunctivitis to severe asthma. Therapeutic intervention focuses on either neutralizing the IgE itself using biologics like omalizumab or modulating the adaptive immune system through allergen-specific immunotherapy to reduce IgE production and increase immune tolerance. Understanding the downstream adaptive components, such as Th2 cell polarization and B cell class switching, is critical for developing next-generation treatments that provide long-term desensitization for cat-allergic patients (Grönlund et al., 2010, Clinical & Experimental Allergy).

Other names

Fel d 1-specific IgECat allergen-specific IgEsIgE to cat danderAnti-Fel d 1 IgE

Drugs targeting cat-specific IgE primarily function by neutralizing circulating IgE or preventing its interaction with high-affinity receptors. Monoclonal antibodies like omalizumab bind to the Fc region of free IgE, preventing it from attaching to the FcεRI receptor on mast cells and basophils, which inhibits the release of inflammatory mediators (Galli & Tsai, 2012, Nature). Allergen-specific immunotherapy (AIT) works by repeatedly exposing the patient to cat allergens (e.g., Fel d 1) to induce immune tolerance, characterized by a shift from Th2 to Th1/Treg responses, a decrease in allergen-specific IgE, and an increase in protective IgG4 antibodies (Akdis & Akdis, 2014, Nature Reviews Immunology).