Sobala ŁF, Szymczak-Kulus K, Kasper Ł, Kasper M, Kaczmarek R, et al.
Glycoconjugate journal •
α-Gal syndrome (AGS) is a type of allergy to red meat and other mammalian products that develops after a tick bite. Symptoms may include urticaria, angioedema, gastrointestinal and respiratory symptoms, and, most dangerously, anaphylactic shock. Among food allergies, it is considered unusual because: (i) the major allergen is not a protein, but a carbohydrate moiety Galα-1,3-Gal, which humans do not synthesize; (ii) it is caused by α-Gal-containing glycoconjugates injected during a tick bite; (iii) the hypersensitivity is effected by IgE antibodies which arise after a class switch from IgG and IgM-class antibodies; (iv) it seems to be triggered by α-Gal-containing glycolipids present in red meat, with delayed onset. Here, we evaluate glycans that may cause AGS, review the data about glycosyltransferases that synthesize α-Gal and related antigens and describe the immune mechanism behind AGS: sensitization and host response to ticks' saliva. In addition, we consider future research avenues that may lead to a better understanding and management of AGS as a modern dietary affliction rooted in an old evolutionary trade-off.
Alpha-gal syndrome is an immunoglobulin E (IgE)-dependent allergy to galactose-α-1,3-galactose, resulting in a delayed anaphylactic reaction to red meat. The syndrome is causally linked to bites from ticks and associated with cross-reactivity to some drugs, e.g. cetuximab. Although cases of alpha-gal allergy have already been reported in a few European countries, to our best knowledge, no cases have been reported so far in Central-Eastern Europe. In the current report, we describe a case of alpha-gal syndrome diagnosed in Poland, to highlight the fact that it may occur in new geographic areas. Within three months, the described patient underwent five anaphylactic reactions with typical clinical manifestations. They developed a few hours after ingestion of red meat (pork, beef or mutton) and were preceded by tick bites. The level of specific IgE antibodies to alpha-gal reached 72.6 kAU/l, whereas the levels of specific IgE antibodies to other food allergens were within the reference range. As the onset of symptoms in this syndrome is usually delayed, numerous cases may be identified as idiopathic anaphylaxis, while early diagnosis is indispensable to avoid potentially life-threatening complications.
