More Specific Testing May Lessen Severity Of Fish Allergies

LEIPZIG, GermanyMore specific testing to identify fish allergies in affected persons may identify allergens not common to all types of seafood, which could lessen the severity of fish allergies, according to a new study published in the Journal of Investigational Allergology and Clinical Immunology.

Researchers at Helmholtz Centre for Environmental Research (UFZ), University of Leipzig and Haukeland University Hospital examined 12 patients to determine the extent of their fish allergies. One of the subjects had developed an allergy to Nile perch (Lates niloticus) after having come into contact with the raw fish following consumption of salmon (Salmo salar), called a "cross allergy." Tests indicated signs of allergies to Nile perch and salmon, but not to Atlantic cod (Gadus morhua).

The most common allergen in fish and crustaceans is parvalbumin, a calcium-binding protein. While other substances may also trigger allergies, such as certain proteins in cell metabolism called aldehyde dehydrogenases, these proteins have been overlooked due to the prevalence of the more frequent parvalbumin.

Researchers concluded the tests that are currently used are very non-specific, whereas more specific testing could identify less common allergens. The most direct way of identifying new allergens is through analyzing the serum of affected patients and the proteins of the allergy source. If certain antibodies in the patients serum bind to the proteins of the food, the allergy is triggered. The identified allergies can be used initially for individual diagnoses and later for epidemiological studies, to determine the relevance of individual allergies.

"For some people who suffer from fish allergies there may be hope of finding a fish that they can tolerate if we managed to make the relevant tests suitable for mass implementation and use them in allergy diagnostics," said Janina Tomm, Ph.D., from the UFZ, who specializes in research into proteins.