Anaphylactic Reactions to Oligosaccharides in Red Meat: a Syndrome in Evolution

A PubMed search was conducted with MeSH terms: galactosyl-(1,3) galactose, oligosaccharides, cetuximab, allergy/hypersensitivity, and anaphylaxis. Reported cases with alpha-gal-mediated reactions were reviewed. This research study was approved by the Institutional Review Board of East Tennessee State University.Thirty-two cases of adults presenting with red-meat induced allergy thought to be related to oligosaccharides have been reported in the literature so far, making this a rare and evolving syndrome. Most of these patients demonstrated delayed reactions to beef, as was seen in the case reported by us in this manuscript. IgE specific to alpha-gal was identified in most patients with variable response to skin testing with beef and pork. Inhibition studies in some cases showed that the IgE antibodies to beef were directed towards alpha-gal in the meat rather than the protein. The patients often reported history of tick bites, the significance of which is unclear at present. Reactions to cetuximab, a monoclonal antibody, are mediated by a similar mechanism, with IgE antibodies directed against an alpha-gal moiety incorporated in the drug structure.Alpha-gal is an oligosaccharide recently incriminated in delayed anaphylactic reactions to mammalian meats such as to beef, pork, and lamb. It appears that anaphylactic reactions to the anti-cancer biological agent, cetuximab, may be linked mechanistically to the same process. More studies are required to understand the underlying molecular basis for these delayed reactions in specific, and their broader implications for host defense in general.Food allergy remains a well-recognized problem that affects people of different ages and can alter their quality of life [1,2]. Its prevalence and incidence seem to be increasing over the past years [3-7] with more cases of food-induced anaphylaxis being reported [8-11]. Food hypersensitivity reactions are usually mediated by IgE antibodies against the incriminated food allergens su