title: [Update on meat allergy. α-Gal: a new epitope, a new entity?].
abstract: The association between the carbohydrate galactose-[alpha]-1,3-galactose (α-Gal) and anaphylaxis was first documented after severe hypersensitivity reactions to cetuximab, a chimeric mouse-human IgG1 monoclonal antibody approved for targeted therapy of carcinomas of colon, as well as of the head and neck region. α-Gal is a ubiquitous glycan moiety expressed on cells and tissue of non-primate mammals. Since this epitope is not expressed in humans, it is very immunogenic for them.  α-Gal is located on the Fab portion of cetuximab and thus on the murine part of the chimera. The anaphylactic reactions to the antibody were mediated by IgE specific for α-Gal. Anti-α-Gal-IgE were first detected in sera of patients from the southeastern U.S. and reacted with a wide range of mammalian allergens. The geographic distribution prompted investigations of sensitization routes apart from the ingestion of red meat, such as tick bites und parasitic infections. Anti-α-Gal-IgE seems to be of clinical relevance for allergy to red meat and for the pork-cat syndrome. It is also associated with a novel form of delayed anaphylaxis, which appears more than 3 hours following the ingestion of red meat (beef, pork and lamb), a phenomenon which is still to be elucidated. For most of these patients conventional skin prick tests with commercial reagents proved insufficient for diagnosis.
authors.affiliation: Klinik für Dermatologie, Allergologie und Venerologie, Universität Lübeck, Lübeck, Deutschland. ujappe@fz-borstel.de
authors.forename: U
authors.initials: U
authors.lastname: Jappe
mesh_terms: D000485:Allergens / Q000276:immunology; D000707:Anaphylaxis / Q000276:immunology*; D000818:Animals; D002417:Cattle; D004187:Disaccharides / Q000276:immunology*; D005260:Female; D005512:Food Hypersensitivity / Q000276:immunology*; D006801:Humans; D006968:Hypersensitivity, Delayed / Q000276:immunology*; D008297:Male; D008460:Meat / Q000009:adverse effects*
chemical_list: D000485:Allergens; D004187:Disaccharides; C055075:galactosyl-(1-3)galactose