Immunoglobulin E and High-affinity immunoglobulin epsilon receptor subunit alpha complex (IgE-FcεRI complex)

The complex formed by Immunoglobulin E (IgE) and its high-affinity receptor, FcεRI, is the central mediator of type I hypersensitivity reactions. IgE is produced by B cells in response to allergens and binds via its Fc region to the FcεRIα subunit on the surface of effector cells, specifically mast cells and basophils [1, 2]. Upon subsequent exposure to the specific allergen, the receptor-bound IgE molecules are cross-linked, triggering a signaling cascade that results in the release of inflammatory mediators like histamine, leukotrienes, and cytokines [4]. This process is responsible for the clinical manifestations of allergic diseases such as asthma, allergic rhinitis, and chronic urticaria [3]. Therapeutic strategies primarily focus on neutralizing free IgE in the circulation to prevent the formation of these complexes [5]. By reducing the amount of free IgE, drugs like omalizumab also lead to a secondary downregulation of FcεRI expression on effector cells, further diminishing the allergic response [3, 5].

Other names

IgE-Fc epsilon RI complexHigh-affinity IgE receptor complexAllergen-specific IgE-receptor complexsIgE-FcεRI complexPatient allergen-specific Immunoglobulin E and associated IgE–FcεRI complexes on effector cells

Neutralization of circulating free IgE to prevent its binding to the high-affinity receptor (FcεRI) on mast cells and basophils, leading to the downregulation of receptor expression and inhibition of allergen-induced mediator release.