Hidden allergens may be defined as allergen deliberately added to food but unlabelled in the ingredient list or present due to unintentional cross contact during food manufacturing itself and, therefore, not recognizable for the consumer. An allergen present in food may also be considered as "hidden" if causing reactions in a patient because of so far unknown cross-reactivity. A novel food allergen is one that has been introduced to human diet for the first time, e.g., kiwi at the beginning of the 1980s, and to which patients develop sensitivity after exposure. A new allergen also can be an IgE-binding molecule that has never been described and identified before in a particular species as allergen source. α-Gal is an ubiquitous glycan moiety expressed on cells and tissue of nonprimate mammals, but not in humans, which is the reason for its strong immunogenicity for the latter. α-Gal is located on the Fab portion of the monoclonal treatment antibody Cetuximab. In 2008, it has been identified as being responsible for severe, sometimes fatal anaphylactic reactions to Cetuximab. Anti-α-Gal-IgE also seem to be responsible for severe allergy to red meat, innards and to gelatine, however, fatal reactions have not been reported so far. Anti-α-Gal-IgE are associated with a novel food allergy, a delayed anaphylaxis (more than 3 hours) following the ingestion of red meat and innards, a phenomenon which is still to be elucidated. An additional characteristic feature is that for most of these patients conventional skin prick tests with commercial reagents proved insufficient for diagnosis. Anti-α-Gal-IgE were first detected in sera from patients in an area of the southeastern U.S. and bound to a wide range of mammalian allergens. The (Chemical Equation Presented) geographic distribution prompted investigations of sensitization routes apart from the ingestion of red meat, like tick bites und parasitic infections.
|Translated title of the contribution||Anaphylaxis caused by hidden food allergens: The α-Gal syndrome|
|Number of pages||10|
|Publication status||Published - 01.01.2014|