Carbohydrate moieties of different
glycoproteins, such as cross-reactive
carbohydrate determinants (CCDs) and
galactose α-1,3-galactose, can induce
IgE reactivity with varied clinical significance. In this study, the possible participation of
glycan from wheat
gliadin, with respect to its
IgE-binding capacity, was investigated in children with
food allergies to wheat. Total
IgE and wheat-specific
IgE quantification, documentation of history, and/or oral food challenge (OFC) were performed for 52 children. Subjects with positive wheat-specific
IgE were characterized as the symptomatic group, never-exposed group, or asymptomatic group.
Sodium dodecyl sulfate-
polyacrylamide gel electrophoresis (SDS-PAGE) and
glycan detection in
gliadin were performed.
IgE binding to
gliadin and deglycosylated
gliadin was measured by immunoblotting and ELISA.
Gliadin-specific
IgE was detected and correlated with wheat-specific
IgE in the symptomatic, never-exposed, and asymptomatic groups. The
glycan range overlapped significantly with the
gliadin range. Deglycosylation of
gliadin reduced the allergenicity of
gliadin. In
gliadin, the allergenicity of the
glycan portion was greater in the symptomatic group than in the never-exposed and asymptomatic groups. We conclude that N-
glycan in
gliadin might exhibit allergenicity as a possible
carbohydrate epitope in
wheat allergy in children.