IgE reactivity to carbohydrate moieties of glycoproteins in wheat allergy

Abstract

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.

Agreement of serum allergen test results with unblocked and blocked IgE against cross‐reactive carbohydrate determinants (CCD) and intradermal test results in atopic dogs

“…By contrast to the previous findings, in humans the presence of IgE against galactose‐α‐1,3‐galactose in red meat was reported to result in severe clinical reactions . Another study showed that IgE against gliadin in wheat led to greater allergenicity in wheat‐allergic symptomatic children compared to nonexposed or asymptomatic individuals, implying that the assumption that those antibodies have no clinical impact is not applicable for all CCDs. In the dog, the presence of anti‐CCD IgE did not lead to polysensitization with IDT, which may indicate that they are clinically irrelevant in canine AD.…”

“…In humans, specific IgE against these glycoproteins has been reported and these anti‐CCD IgE antibodies are believed to be a cause of positive in vitro test results . Anti‐CCD IgE antibodies against CCDs in plants and insects for the most part do not seem to have clinical relevance, although notable exceptions such as galactose‐α‐1,3‐galactose in red meat and glycan in wheat have been reported . One possible reason for the inability to cause clinical symptoms is the monovalent structure of the CCDs, preventing cross‐linking and mast cell degranulation …”

Food Allergy

“…The size, solubility, and stability ensure protein transport and survival, whereas glycation may affect stability and immunogenicity (Shreffler et al 2006, Ilchmann et al 2010, Song et al 2015. For instance, the carbohydrate moiety of peanut vicilin is involved in dendritic cell activation and T H 2 cell maturation (Shreffler et al 2006).…”

<p>Serum IL-8 and VEGFA are Two Promising Diagnostic Biomarkers of Asthma-COPD Overlap Syndrome</p>

“…These asthmatic patients who also manifest the symptoms of COPD are diagnosed with asthma-COPD overlap syndrome (ACOS). 3,4 Meanwhile, patients with COPD with good obstruction reversibility, whereas increased eosinophil counts, can also be classified as ACOS. 5 Most ACOS patients are elderly and manifest the symptoms of both asthma and COPD.…”