Anaphylaxien auf rotes Fleisch : Galactose-α-1,3-galactose (α-Gal ) - ein interessantes Allergen. [Anaphylaxis to red meat: galactose-alpha-1,3-galactose (alpha-Gal) - an interesting allergen]

Anaphylaxis to red meat: galactose-alpha-1,3-galactose (alpha-Gal) - an interesting allergen Meat allergy comprises symptoms as contact dermatitis, rhinitis/allergic asthma, urticaria and severe anaphylaxis. Clinical manifestations may occur in both, children and adults. Different routes of sensitization are hypothesized. Few meat allergens have been identified so far, some of them only poorly characterized. Galactose-alpha-1,3-galactose (alpha-Gal), a carbohydrate structure expressed on cells and tissues of non-primate mammals was shown to be the culprit allergen for hypersensitivity reactions only to red meat (i.e. pork, beef, lamb etc.). Symptoms develop characteristically in adults with a delay of 3 to 10 hours after consuming red meat. {IgE-mediated} allergy to alpha-Gal may, therefore, be one so far unidentified cause of idiopathic anaphylaxis. Interestingly, alpha-Gal was first identified as allergenic epitope causing of hypersensitivity reactions to cetuximab. Cetuximab is a monoclonal chimeric antibody, approved for therapy of metastasizing {EGFR-expressing} colon carcinoma and squamous cell carcinoma of head and neck, which is produced in a mouse myeloma cell line, resulting in expression of alpha-Gal on the fab-region of cetuximab, binding {IgE} antibodies specific for alpha-Gal. Anaphylaxis to cetuximab is reported to occur overall in 3% of patients. In certain geographic areas of the {USA}, however, incidence of alpha-Gal-associated hypersensitivity to cetuximab seems to be much higher. It could be shown that the sting of an endemic tick, Amblyomma americanum, can induce the production of {IgE-antibodies} to alpha-Gal and might, therefore, explain geographic differences in sensitization to alpha-Gal. As a commercial test for {IgE-antibodies} to alpha-Gal is now available, patients should be tested for pre-existing antibodies before the first application of cetuximab.