Alpha-gal syndrome: challenges to understanding sensitization and clinical reactions to alpha-gal

Expert Rev Mol Diagn. 2020 Sep;20(9):905-911. doi: 10.1080/14737159.2020.1792781. Epub 2020 Jul 14.

Abstract

Introduction: The α-Gal syndrome (AGS) is a type of allergy characterized by an IgE antibody response against the carbohydrate Galα1-3Galβ1-4GlcNAc-R (α-Gal). Tick bites are recognized as the most important cause of anti-α-Gal IgE antibody increase in humans. Several risk factors have been associated with the development of AGS, but their integration into a standardized disease diagnosis has proven challenging.

Areas covered: Herein we discuss the current AGS diagnosis based on anti-α-Gal IgE titers and propose an algorithm that considers all co-factors in the clinical history of α-Gal-sensitized patients to be incorporated into the AGS diagnosis. The need for identification of host-derived gene markers and tick-derived proteins for the diagnosis of the AGS is also discussed.

Expert opinion: The current AGS diagnosis based on anti-α-Gal IgE titers has limitations because not all patients sensitized to α-Gal and with anti-α-Gal IgE antibodies higher than the cutoff (0.35 IU/ml) develop anaphylaxis to mammalian meat and AGS. The basophil activation test proposed to differentiate between patients with AGS and asymptomatic α-Gal sensitization cannot be easily implemented as a generalized clinical test. In coming years, the algorithm proposed here could be used in a mobile application for easier AGS diagnosis in the clinical practice.

Keywords: Alpha-gal; allergy; antibody; interleukin; mammalian meat; tick.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms
  • Allergens / immunology*
  • Anaphylaxis / immunology
  • Animals
  • Basophils / immunology
  • Basophils / metabolism
  • Biomarkers
  • Disease Management
  • Food Hypersensitivity / diagnosis*
  • Food Hypersensitivity / immunology*
  • Food Hypersensitivity / metabolism
  • Humans
  • Immunization
  • Immunoglobulin E / immunology*
  • Tick Bites / complications
  • Trisaccharides / immunology*

Substances

  • Allergens
  • Biomarkers
  • Trisaccharides
  • alpha-galactosyl epitope
  • Immunoglobulin E

Supplementary concepts

  • red meat allergy