Alpha-galactose allergy

From MEpedia, a crowd-sourced encyclopedia of ME and CFS science and history

Alpha-galactose allergy (also known as alpha-gal allergy, alpha-gal syndrome, or mammalian meat allergy (MMA)) is a reaction to the carbohydrate galactose-alpha-1,3-galactose (alpha-gal).[1][2] In alpha-galactose allergy, the body experiences a sharp increase in immunoglobulin E (IgE) upon contact with the meat-derived carbohydrate.[3]

The alpha-gal molecule is found in all mammals except apes, humans, and Old World monkeys.[4] Since humans do not naturally produce this carbohydrate, humans do not have an pre-existing immune tolerance to the carbohydrate. The allergy most often begins when a Lone Star tick bite transmits alpha-gal into the body. In some people, an immune system reaction may later produce mild to severe allergic reactions when red meat is eaten.[5]

The cancer drug cetuximab (trade name Erbitux) contains the alpha-gal carbohydrate, since it is manufactured from mice. Cetuximab can cause a reaction in people who live in regions with a high population of Lone Star ticks, suggesting a link between Lone Star tick bites and an increased vulnerability to alpha-gal syndrome.[5]

Treatment[edit | edit source]

There is no treatment, other than not eating red meat.[5]

Symptoms[edit | edit source]

See also[edit | edit source]

Learn more[edit | edit source]

References[edit | edit source]

  1. Hilger, Christiane; Fischer, Jörg; Wölbing, Florian; Biedermann, Tilo (2019). "Role and Mechanism of Galactose-Alpha-1,3-Galactose in the Elicitation of Delayed Anaphylactic Reactions to Red Meat". Current Allergy and Asthma Reports. 19 (1). doi:10.1007/s11882-019-0835-9. ISSN 1529-7322. PMC 6344609. PMID 30673913.
  2. "The Oligosaccharide Galactose-α-1,3-Galactose and the α-Gal Syndrome: Insights from an Epitope that is Causal in Immunoglobulin E-Mediated Immediate and Delayed Anaphylaxis". European Medical Journal. July 17, 2018. Retrieved December 9, 2019.
  3. Commins, Scott P.; Platts-Mills, Thomas A.E. (February 2013). "Delayed Anaphylaxis to Red Meat in Patients with IgE Specific for Galactose alpha-1,3-Galactose (alpha-gal)". Current allergy and asthma reports. 13 (1): 72–77. doi:10.1007/s11882-012-0315-y. ISSN 1529-7322. PMC 3545071. PMID 23054628.
  4. Galili, Uri (September 1, 1993). "Evolution and pathophysiology of the human natural anti-α-galactosyl IgG (anti-Gal) antibody". Springer Seminars in Immunopathology. 15 (2): 155–171. doi:10.1007/BF00201098. ISSN 1432-2196.
  5. 5.0 5.1 5.2 "Alpha-gal syndrome - Symptoms and causes". Mayo Clinic. Retrieved October 27, 2019.
  6. "Omalizumab". Reactions Weekly. 1740 (1): 254–254. February 2019. doi:10.1007/s40278-019-58147-3. ISSN 0114-9954.