As early as 2018, a research team of the MedUni Vienna showed that strict avoidance of all types of fish is in fact only necessary for few fish-allergy sufferers. However, reliable tests to determine which types could be tolerated and eaten have not been available until now. In their current study, the researchers demonstrate that a new and effective diagnostic procedure. The results of the study were published in the renowned "Journal of Allergy and Clinical Immunology: In Practice".
In order to arrive at a meaningful result, the scientists led by Heimo Breiteneder from the Institute of Pathophysiology and Allergy Research at the MedUni Vienna and Tanja Kalic from the Karl Landsteiner Private University for Health Sciences included test subjects from six different countries in their study. After all, there are significant regional differences in the species and allergen diversity of the fish consumed, as well as in the method of preparation, which affects the stability of the main fish allergen parvalbumin.
In cooperation with researchers from Austria, China, Denmark, Luxembourg, Norway and Spain as well as the industrial partner MacroArray Diagnostics, blood samples were taken from 263 patients suffering from a clinically confirmed fish allergy. The multiplex IgE test used for this purpose, with which the concentration of IgE antibodies against ten fish species is measured simultaneously, proved to be an effective instrument for the differentiation between allergy-causing and tolerated fish species for the patients. "However, we recommend that the Multiplex-IgE-Test not only includes parvalbumin, but also extracts of various bony fish and cartilaginous fish", emphasises Heimo Breiteneder, the director of the study. Potential reactions to other less commonly recognised allergens can be tested with the addition of fish extracts.
Frequent tolerance of cartilaginous fish
With the aid of this diagnostic procedure, up to 90 % of the patients tested negative for cartilaginous fish (e.g. rays, sharks), which indicated a potential tolerance: "If no allergy-causing IgE is detected in patients for one or more fish species in this test procedure, this result will have to be confirmed by a provocation test in a controlled clinical setting," adds Heimo Breiteneder and warns fish allergy sufferers against self-experimentation. Fish allergy is considered one of the most dangerous food allergies as it often leads to life-threatening symptoms, such as anaphylactic shock. In order to prevent this, those affected are currently advised to strictly avoid fish.
Back in 2018, Tanja Kalic, Heimo Breiteneder and an international research team demonstrated in a study that fish allergy sufferers are more likely to tolerate cartilaginous fish rather than the far more commonly consumed bony fish. According to the researchers, the diagnostic method now being researched could not only help fish allergy sufferers to have a more extensive menu. The approach can also be applied to other food allergens and help to identify potentially tolerated foods. Multiplex-IgE test with fish allergens and extracts are already being conducted in specialised allergy centres.
Publication: The Journal of Allergy and Clinical Immunology: In Practice
Identification of potentially tolerated fish species by multiplex IgE testing of a multinational fish-allergic patient cohort
Tanja Kalic, Annette Kuehn, Martina Aumayr, Joan Bartra, Carsten Bindslev-Jensen, Françoise Codreanu-Morel, Olga Domínguez, Peter Forstenlechner, Wolfgang Hemmer, Sandip D Kamath, Agnes Leung, Nicki Leung, Yuri Lifanov, Charlotte G Mortz, Mariona Pascal, Robin Ristl, Martin Sørensen, Éykü Ézülmez, Lusine Yeghiazaryan, Gary Wong, Christine Hafner, Heimo Breiteneder
In this cluster, led by Rudolf Valenta from the MedUni Vienna’s Institute of Pathophysiology and Allergy Research, approximately 100 scientists have been working on 16 different research projects to improve diagnostic and therapeutic options for allergies since 2020. Heimo Breiteneder and Tanja Kalic are conducting research in the sub-project DARC-06 "Molecular allergy testing for therapeutic and clinical decision making" of Christine Hafner, Clinical Department of Skin and Venereal Diseases, University Hospital St. Pölten.