Aktuelle Ernährungsmedizin 2023; 48(03): 195-208
DOI: 10.1055/a-1870-7328
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Das Alpha-Gal-Syndrom – eine komplexe Allergie im interdisziplinären Kontext

Alpha-GAL syndrome: A complex allergy in an interdisciplinary context
Uta Jappe

Das Alpha-Gal-Syndrom umfasst eine um 3–12 Stunden verzögert einsetzende z.T. schwere Nahrungsmittelanaphylaxie. Diese Latenz kompliziert die Diagnosestellung ebenso wie die Tatsache, dass das auslösende Allergen ein Zucker ist, da proteinbasierte Testverfahren negativ bleiben können. Diese Arbeit beschreibt die Entdeckung dieser neuen Entität, ihre Ursachen, ihre Risiken und die relevante Diagnostik.

Abstract

The alpha-Gal syndrome is characterized by a 3–12 hour delay in onset of sometimes severe food anaphylaxis to mammalian meat and products. Alpha-Gal (galactose-alpha 1,3-galactose) is a disaccharide not existent in humans, which makes it immunogenic. It induces IgE antibody-mediated allergy with a significantly delayed onset of response to red meat and innards (3–6 [up to 12] hours). This latency complicates diagnosis, as does the fact that the triggering allergen is not a protein as known for other food allergies, but a sugar, so that protein-based testing methods often remain negative. Since alpha-Gal can also be found in drugs depending on how they are manufactured or extracted, it can also induce immediate-type allergies to drugs. One example is the chimeric treatment antibody Cetuximab. The intravenous injection will induce an immediate type reaction after several minutes in individuals with pre-existing IgE-antibodies to alpha-Gal.

The main route of sensitization is bites from certain tick species, so alpha-Gal syndrome is actually considered a tick-borne disease.

Most patients with alpha-Gal syndrome develop skin symptoms such as pruritus, erythema, local and or generalized urticaria and/or angioedema, and approximately 70% develop gastrointestinal symptoms. Half of the patients suffer from anaphylaxis (reactions that involve two or more organ systems). Approximately one-fifth describe isolated gastrointestinal symptoms, representing an endoluminal food allergy.

It is likely that gastrointestinal symptoms are an underdiagnosed symptom of the alpha-Gal syndrome. Therefore, if new onset gastrointestinal symptoms such as periodic cramping, nausea, and diarrhoea occur, alpha-Gal syndrome should be considered, and the appropriate diagnostics be performed by an allergist.



Publication History

Article published online:
26 May 2023

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