Concomitant sensitization to legumin, Fag e 2 and Fag e 5 predicts buckwheat allergy

Clin Exp Allergy. 2018 Feb;48(2):217-224. doi: 10.1111/cea.13068. Epub 2017 Dec 22.


Background: Buckwheat (Fagopyrum esculentum) has become increasingly popular as a healthy food in Europe. However, for sensitized individuals, consumption can cause anaphylactic reactions. The aim of this study was to identify individual well-characterized buckwheat allergens for component-resolved diagnosis.

Methods: Patients were selected by positive skin prick test to buckwheat and divided into two groups: (1) sensitized to buckwheat without clinical symptoms and (2) buckwheat allergy. Buckwheat proteins were extracted from raw buckwheat seeds, purified applying a combination of protein precipitation and chromatographic methods, and analyzed by IgE immunoblotting and ELISA.

Results: Buckwheat-allergic patients had a significantly larger median skin prick test weal diameter for buckwheat than the sensitized group and the positive control. Also, IgE immunoblotting clearly showed a distinct pattern in sera from allergic patients when compared to sensitized individuals. Several IgE-reactive proteins were purified from crude buckwheat extract, namely legumin (Fag e 1 plus its large subunit), Fag e 2 (2S albumin), and newly identified Fag e 5 (vicilin-like) as well as hevein-like antimicrobial peptides, designated Fag e 4. All four allergens showed superior diagnostic precision compared to extract-based ImmunoCAP with high sensitivity as well as high specificity.

Conclusions: Patients with clinical symptoms clearly show a distinct allergen recognition pattern. We characterized a buckwheat vicilin-like protein as a new relevant marker allergen, designated Fag e 5. Additionally, another new allergen, Fag e 4, potentially important for cross-reactivity to latex was added to the allergen panel of buckwheat. Further, our data show that the full-length legumin comprising both, large and small subunit should be applied for component-resolved diagnosis. Our data indicate that concomitant sensitization to legumin, Fag e 2 and Fag e 5, predicts buckwheat allergy.

Keywords: IgE; allergens; buckwheat; component-resolved diagnosis; food allergy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Allergens / immunology*
  • Antigens, Plant / immunology*
  • Biomarkers
  • Child
  • Enzyme-Linked Immunosorbent Assay
  • Fagopyrum / adverse effects*
  • Female
  • Humans
  • Immunoglobulin E / immunology
  • Male
  • Middle Aged
  • Prognosis
  • Wheat Hypersensitivity / diagnosis*
  • Wheat Hypersensitivity / immunology*
  • Young Adult


  • Allergens
  • Antigens, Plant
  • Biomarkers
  • Fag e 2 allergen, Fagopyrum esculentum
  • Immunoglobulin E