Immunoglobulin epsilon (IgE) (IgE)

Immunoglobulin epsilon (IgE) is the primary mediator of Type I hypersensitivity reactions, including those triggered by grass group 5 allergens such as Phl p 5 from Timothy grass. In sensitized individuals, allergen-specific IgE (sIgE) is produced and bound to high-affinity receptors (FcεRI) on mast cells and basophils, as well as low-affinity receptors (CD23) on B cells. Upon exposure to grass pollen, group 5 allergens cross-link the receptor-bound IgE, initiating a signaling cascade that leads to the degranulation of effector cells and the release of inflammatory mediators like histamine and leukotrienes. This molecular interaction is the fundamental cause of allergic rhinitis, conjunctivitis, and asthma in patients with grass pollen allergy. Therapeutic strategies targeting this axis include monoclonal antibodies that neutralize circulating IgE (e.g., Omalizumab) and allergen-specific immunotherapy (AIT) designed to induce immunological tolerance. The high-affinity receptor, FcεRI, is a tetrameric complex where the alpha chain (FCER1A) directly binds the Fc region of IgE, making it a critical component of the allergic signaling pathway. Monitoring sIgE levels and basophil activation are key for diagnosing sensitivity and assessing the efficacy of treatments targeting this axis.

Other names

Immunoglobulin EAllergen-specific IgEsIgEIg epsilonHigh affinity immunoglobulin epsilon receptor (FcεRI)Low affinity immunoglobulin epsilon receptor (CD23)

IgE neutralization, inhibition of IgE binding to FcεRI and CD23 receptors, and induction of immunological tolerance through allergen-specific immunotherapy (AIT).