Usefulness of specific IgE antibodies to ω-5 gliadin in the diagnosis and follow-up of Japanese children with wheat allergy

Abstract

Gliadins have been implicated in IgE-mediated allergy to ingested wheat. ω-5 gliadin seems to be a clinically relevant allergen component in children with immediate wheat allergy (WA), but contradictory results have been published. To investigate whether specific IgE (sIgE) antibodies to recombinant ω-5 gliadin could be used as a marker for oral wheat challenge outcome in wheat-sensitized children and to study whether measurements of sIgE to ω-5 gliadin are useful in monitoring children with WA to assess whether the allergy is outgrown or persistent. Eighty-eight serum samples from children sensitized to wheat were collected consecutively. sIgE to ω-5 gliadin was related to a physician's diagnosis of WA. Sixty-seven of 88 children sensitized to wheat were diagnosed as having WA. The geometric mean concentrations of sIgE to ω-5 gliadin were 2.04 kU(A)/L (range, <0.35-100 kU(A)/L) in children with WA and 0.40 kU(A)/L (range, <0.35-1.8 kU(A)/L) in children without WA. At follow-up, after being on a wheat-free diet for approximately 2 years, the sIgE titers to ω-5 gliadin were below 0.35 kU(A)/L (mean, 0.34 kU(A)/L; range, 0.34-2.3 kU(A)/L) in 10 of 15 children with outgrown WA. Conversely, in 12 of 14 children with persistent WA, the sIgE titers to ω-5 gliadin were still elevated (mean, 5.89 kU(A)/L; range, 0.34-16.3 kU(A)/L). sIgE to ω-5 gliadin can be used as an accurate alternative to potentially dangerous wheat food challenges in monitoring WA.