ALLERGENIC ACTIVITY OF HEATED AND OVOMUCOID-DEPLETED EGG-WHITE

Background: No egg white products have been clearly proven to be hypoa llergenic. The role of egg white proteins in allergic reactions to egg s is still debatable. Objective: This study was designed to determine the importance of ovomucoid, an egg,white protein, in the development of allergies to egg white. Methods: We performed a double-blind, place bo-controlled food challenge in subjects with high levels of IgE antib odies for egg white to compare the allergenicities of heated and ovomu coid-depleted egg white, freeze-dried egg white, and heated egg white, Levels of IgE antibodies for egg white, ovomucoid, ovalbumin, ovotran sferrin, and lysozyme were measured in serum by RAST. Results: Twenty- one of 38 subjects with positive challenge responses to freeze-dried e gg white had negative challenge responses to heated egg white, whereas 16 of 17 subjects (94.1%) with positive responses to heated egg white did not respond to the heated and ovomucoid-depleted egg white challe nge. The subjects with positive challenge responses to freeze-dried eg g white tended to have higher IgE antibody values to ovomucoid than th ose with negative responses. IgE antibody levels to ovomucoid were sig nificantly higher in subjects with positive responses to a challenge w ith heated egg white than in those with no response. There were no sig nificant differences in the levels of IgE antibodies to the other prot eins, except ovomucoid, in the negative-response and positive-response groups in challenge tests with freeze-dried and heated egg white. Con clusion: The heated and ovomucoid-depleted egg white preparation was l ess allergenic than heated or freeze-dried preparations. Ovomucoid has a more important role in the pathogenesis of allergic reactions to eg g white than other proteins in egg white.