Modulation of egg white protein allergenicity under physical and chemical treatments

Abstract

Hen eggs are one of the most common causes of food allergic reactions.Egg white, which is generally considered more allergenic than egg yolk, has four major allergenic proteins namely, ovomucoid, ovalbumin, ovotransferrin and lysozyme which are defined as immunodominant egg white proteins (EWP).The objectives of the present work were first to evaluate sensitivity to EWP of the population in the region of Fez-Meknes in Morocco, and then to study the effect of acid treatment and heating on the allergenicity of EWP.A cross-sectional study was carried out at the University Hospital in Fez and at analytical laboratories in Meknes in which 446 adults were recruited to establish a serum bank.Sera bank was used to evaluate specific IgE reactivity to EWP and the reactivity of this IgE to native and to heat-and acid-treated EWP.Immunoblots were also carried out to characterise the allergenic components.The results showed that 9.5% of the patients reported allergy to food.Among these patients, 4.2% reported allergy to eggs, 2.5% to peanuts and 0.4% to wheat flour.The study of the effect of temperature and acidity on the allergenicity of EWP showed that more than 50% of sera showed a decrease superior to 30% under heating or acid treatment.With a combination of these treatments, 75% of the sera showed a reduction of more than 30%.By means of immunoblot, we have shown that ovotransferrin and lysozyme are the major allergens for the population studied.