Role and mechanism of Galactose-Alpha-1,3-Galactose in the elicitation of delayed anaphylactic reactions to red Meat.

PURPOSE OF REVIEW: The alpha-Gal (alpha-Gal) syndrome is characterized by the presence of IgE antibodies directed at the carbohydrate galactose-alpha-1,3-galactose (alpha-Gal). In this article, we review the presence of alpha-Gal in food and non-food sources; we discuss the evolutionary context of the antibody response to alpha-Gal and highlight immune responses to alpha-Gal and other carbohydrates. RECENT FINDINGS: IgE antibodies have been associated with delayed allergy to red meat. In addition to food, drugs, and other products of animal origin are increasingly perceived as a risk for patients sensitized to alpha-Gal. The link between tick bites and anti-alpha-Gal IgE-antibody production that has been established first by epidemiological studies has now been confirmed in mouse models. The anti-alpha-Gal immune response is complex and characterized by a unique feature. IgM and IgG antibodies have been found to confer protection against pathogens whereas the IgE-response to alpha-Gal is detrimental and causes severe reactions upon exposure to mammalian meat and other products.