Individualized IgE-based dosing of egg oral immunotherapy and the development of tolerance.
BACKGROUND
Hen's egg allergy is among the most common food allergies in childhood and predicts later development of allergic disease. The optimal efficacy and mechanism(s) of egg allergen immunotherapy are poorly understood.


OBJECTIVE
To enhance immunologic and clinical outcomes of egg oral immunotherapy (OIT) using a conditionally increased dosing strategy.


METHODS
In an open-label clinical trial of egg OIT, egg-allergic children ingested daily doses of egg protein that were gradually increased based on the egg white (EW) IgE level. Skin prick test reactivity and EW- and ovomucoid-specific cellular and humoral responses were measured longitudinally. To confirm clinical tolerance, patients underwent double-blinded, placebo-controlled food challenges 1 month after completing the dosing protocol.


RESULTS
Children aged 3 to 13 years with characteristics of clinical egg allergy were enrolled. All 6 patients who completed the entire protocol developed clinical tolerance to egg during the study. The median wheal diameter on EW skin prick testing decreased from 10 to 2.5 mm during OIT (P = .03). Both EW and ovomucoid IgE levels significantly decreased during the study (median EW IgE level: from 18.8 kU/L at baseline to 3.9 kU/L, P = .03), and corresponding IgG4 levels increased (median EW IgG4 level: from 0.65 mg/L at baseline to 86.15 mg/L, P = .03). Transient increases were seen in egg-induced interleukin 10 (P = .06) and transforming growth factor β (P = .18) levels, and the ratio of T(H)2:T(H)1 cytokine production was decreased (P = .25).


CONCLUSIONS
Egg OIT is associated with tolerance acquisition in children with persistent egg allergy. Individualized dosing regimens may be necessary to achieve a full therapeutic effect in some patients.
Division of Pediatric Allergy and Immunology, Duke University School of Medicine, Durham, North Carolina 27710, USA. brian.vickery@duke.edu
Brian P
BP
Vickery
Laurent
L
Pons
Michael
M
Kulis
Pamela
P
Steele
Stacie M
SM
Jones
A Wesley
AW
Burks
D000284:Administration, Oral; D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D016207:Cytokines / Q000097:blood; D003888:Desensitization, Immunologic / Q000379:methods*; D004311:Double-Blind Method; D021181:Egg Hypersensitivity / Q000276:immunology* / Q000628:therapy*; D004527:Egg Proteins / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D007108:Immune Tolerance; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology*; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D008297:Male; D016896:Treatment Outcome
D016207:Cytokines; D004527:Egg Proteins; D007074:Immunoglobulin G; D007073:Immunoglobulin E