Abstract
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.