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.