Cat dander allergen extract (Fel d)

Cat dander allergen extract is a complex biological preparation containing the allergenic proteins found in the dander, hair, and saliva of the domestic cat (Felis catus). The most prominent component is Fel d 1, a secretoglobin that is recognized by IgE antibodies in approximately 90% of cat-allergic individuals and is the primary driver of allergic symptoms (Grönlund et al., 2010). The extract is traditionally used in allergen-specific immunotherapy (AIT) to induce clinical tolerance by modulating T-cell responses and stimulating the production of protective IgG4 blocking antibodies (Akdis & Akdis, 2014; Shamji & Durham, 2017). More recently, specific components of the extract, particularly Fel d 1, have become targets for novel therapeutic interventions, such as the development of neutralizing monoclonal antibodies like REGN1908 and REGN1909 (Orengo et al., 2018). These therapies aim to prevent the allergen from cross-linking IgE on the surface of mast cells and basophils, thereby inhibiting the release of inflammatory mediators like histamine (Galli et al., 2008). Clinical applications of the extract and its derivatives are focused on managing allergic rhinitis, conjunctivitis, and asthma in patients with confirmed cat sensitivity (Cox et al., 2011). Safety remains a primary concern in the use of whole extracts due to the risk of systemic allergic reactions and anaphylaxis during administration (Epstein et al., 2014).

Other names

Felis catus allergen extractCat hair extractCat pelt extractCat hair and dander extractFel d 1Fel d 4

Allergen-specific immunotherapy (AIT) induces immunological tolerance through T-cell modulation and IgG4 production, while monoclonal antibodies like REGN1908/1909 directly bind and neutralize the Fel d 1 allergen to prevent IgE-mediated activation (Orengo et al., 2018; Akdis & Akdis, 2014).