Immunological and biochemical properties of egg allergens

Food allergies or food intolerances affect nearly everyone at some point. "Food Allergy" refers to all interactions between molecules derived from the food supply and the immune system. Food allergies can be sub-divided into IgE (Immunoglobulin E) -mediated hypersensitivities and cell mediated hypersensitivities, but in most of the cases is IgE mediated. There has been an increased prevalence of food allergy reactions in the last decade. Approximately 23% of adults and 5-7% of children are affected by food allergy. Hen's egg is one of the most common causes of food allergic reactions, particularly in children. The prevalence of egg allergy is about 35% of food allergic children. It usually disappears by age five to seven years, but may sometimes be lifelong. Egg white, which is generally considered more allergenic than egg yolk, has four major allergenic proteins namely, ovomucoid (Gal d 1), ovalbumin (Gal d 2), ovotransferrin (Gal d 3), and lysozyme (Gal d 4) which are defined as immuno dominant proteins of egg white in egg allergic patients. Detailed characterization of the biochemical, immunological and structural properties of the major two allergens of the egg white, the ovalbumin and the ovomucoid have been studied. Studies of the B cell and T cell epitopes of these allergens have been summarized and mechanisms to reduce allergic reactions of these proteins at their molecular level has been evaluated in detail.