Ovomucoid-specific IgD increases in children who naturally outgrow egg allergy

Background: The majority of egg-allergic children outgrow hypersensitivity against heated egg and then raw egg over time. The roles of ovomucoid (OVM)- and ovalbumin (OVA)-specific IgD in children who naturally outgrow egg allergy are uncertain. We investigated whether specific IgD to egg white (EW), OVM, and OVA correlate with allergen-specific IgE and can predict the development of immune tolerance to egg allergens. Methods: The tolerated doses of cooked egg white, which were determined by oral food challenge and/or an episode of accidental ingestion and corresponding specific IgE, IgG4 and IgD levels were evaluated in 57 children with egg allergy and 23 non-egg allergic children. Results: Patients avoiding all forms of egg had lower EW-, OVM-, and OVA-specific IgD and IgG4 than those partially avoiding egg, those that had outgrown egg allergy, and non-egg allergic children. The ratio of OVM-specific IgD to OVA-specific IgD increased depending on the ingestible amounts of boiled EW, whereas the ratio of OVM-specific IgG4 to OVA-specific IgG4 did not change. Receiver operating curve analysis revealed that the ratio of OVM-specific IgE to OVM-IgD was the best index to discriminate intolerant from tolerant egg-allergic patients. Conclusion: The production of OVM-specific IgD differs from OVM-specific IgG4 as children naturally outgrow egg allergy. The ratio of OVM-specific IgE to OVM-specific D is useful in distinguishing egg-sensitized patients with clinically reactive egg allergy from those who naturally outgrow egg allergy.