Abstract
Ovomucoid is a heat resistant protein found in egg white with a molecular weight of 28000. Although ovomucoid-specific IgE titration has of late been regarded useful in determining consumption of heated hen's eggs, specific statistical data on its sensitivity are few. We undertook a study on its sensitivity and correlation with related antigens using specimens referred to our laboratory. The study population consisted of 1778 cases referred to our laboratory from January to October 2001 from other departments for allergen tests for food allergy. 724 cases (40.7%) tested positive for ovomucoid-specific IgE antibodies. With regard to age variation, peak sensitivity was at age 2 with 46.0%, and decreased with increasing age. In addition, in 50 normal subjects, there was only one case of Class 1 antibody titer, and 0% in Class 2 or higher. Regarding relations with other food allergens, there was a high correlation with allergens with respect to antigenicity, with egg white showing the highest correlation (r=0.869), followed by egg yolk (r=0.861), and milk (r=0.574) . Moreover, when egg white and ovomucoid were measured simultaneously, egg white tested positive and ovomucoid, negative in 236 out of 899 cases (26.8%) . In contrast, only 24 out of 687 specimens (3.5%) were ovomucoid positive and egg white negative. From these results, it is estimated that approximately one-fourth of patients with an egg white allergy can consume heated hen's eggs.
The difference between egg white and ovomucoid sensitivity suggests that measurement of the specific IgE antibody may be an effective parameter in food consumption guidance for allergy patients.
