Identification of peroxidase-1 and beta-glucosidase as cross-reactive wheat allergens in grass pollen-related wheat allergy

Allergol Int. 2021 Apr;70(2):215-222. doi: 10.1016/j.alit.2020.09.005. Epub 2020 Oct 21.


Background: Some patients with wheat-dependent exercise-induced anaphylaxis (WDEIA) or wheat allergy showed negative ω-5 gliadin-specific IgE test and high level of grass pollen-specific IgE. It was presumed that these patients developed allergic reaction upon cross-reaction of their IgE antibodies raised against grass pollen allergens to wheat allergens. This study aimed to clarify clinical characteristics and wheat allergens of this phenotype of WDEIA/wheat allergy, which were tentatively diagnosed as grass pollen-related wheat allergy (GPWA).

Methods: A total of six patients with GPWA were enrolled, and controls were 17 patients with grass pollen allergy but no episode of wheat allergy, and 29 patients with other wheat allergies: 18 with conventional WDEIA and 11 with hydrolyzed wheat protein allergy. Sensitization to wheat proteins was determined by basophil activation test (BAT). IgE-binding proteins in wheat flour were identified by immunoblotting followed by mass spectrometry. Wheat allergen-specific IgE tests were established by CAP-FEIA system.

Results: All the six patients with GPWA were sensitized to water-soluble wheat proteins in BAT and IgE-immunoblotting, and peroxidase-1 (35 kDa) and beta-glucosidase (60 kDa) were identified as specific IgE-binding wheat proteins. The binding of patient IgE to these proteins was inhibited by pre-incubation of patient sera with grass pollen. The peroxidase-1- and beta-glucosidase-specific IgE tests identified three and four of six patients with GPWA, respectively, but only two of 29 controls, indicating high specificity of these tests.

Conclusions: Peroxidase-1 and beta-glucosidase are specific wheat allergens for GPWA among grass pollen allergy and other types of wheat-induced food allergies.

Keywords: Allergens; Cross-reactivity; Food allergy; Grass; Wheat.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Allergens / immunology*
  • Antigens, Plant / immunology*
  • Basophils / immunology
  • Cross Reactions
  • Female
  • Humans
  • Immunoglobulin E / immunology
  • Male
  • Middle Aged
  • Peroxidase / immunology*
  • Plant Proteins / immunology*
  • Poaceae / immunology*
  • Pollen / immunology*
  • Triticum / immunology*
  • Wheat Hypersensitivity / immunology*
  • beta-Glucosidase / immunology*


  • Allergens
  • Antigens, Plant
  • Plant Proteins
  • Immunoglobulin E
  • Peroxidase
  • beta-Glucosidase