Galactose-α-1,3-Galactose: Atypical Food Allergen or Model IgE Hypersensitivity?
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Purpose of Review
Galactose-α-1,3-galactose (α-gal) is a carbohydrate allergen with several unique characteristics. In this article, we discuss some recent advances in our understanding of the ‘alpha-gal syndrome,’ highlight data supporting the role of ticks in pathogenesis, and speculate on immune mechanisms that lead to sensitization.
First described as the target of IgE in individuals suffering immediate hypersensitivity reactions to the novel anti-EGF monoclonal antibody cetuximab, it is now clear that α-gal sensitization is associated with mammalian meat allergy as well as reactions to other mammalian products. Unlike traditional IgE-mediated food allergies, reactions to α-gal often do not manifest until several hours following an exposure, although co-factors can influence the presentation. Multiple pieces of evidence, including recent work with a mouse model, point to the fact that sensitization is mediated by exposure to certain hard ticks and increasingly we are aware of its globally widespread impact.
The oligosaccharide α-gal represents a novel allergen with several unusual clinical features. It has been recognized now on multiple continents and its clinical presentation can be quite variable. Moreover, efforts to delineate the mechanisms leading to α-gal sensitization may have ramifications for our broader understanding of type 2 immunity.
KeywordsAlpha-gal (α-gal) Food allergy Red meat allergy Th2 Type 2 immunity
Compliance with Ethical Standards
Conflict of Interest
Dr. Platts-Mills reports grants from NIAID AI-20565 and support for IgE assays from Thermo-Fisher/Phadia. Drs. Wilson, Schuyler, and Schroeder declare no conflicts of interest relevant to this manuscript.
Human and Animal Rights and Informed Consent
This article does not contain any studies with human or animal subjects performed by any of the authors.
All reported studies/experiments with human or animal subjects performed by the authors have been previously published and complied with all applicable ethical standards (including the Helsinki Declaration and its amendments, institutional/national research committee standards, and international/national/institutional guidelines).
Papers of particular interest, published recently, have been highlighted as: • Of importance •• Of major importance
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