Comparison of allergenic properties of salmon (Oncorhynchus nerka) between landlocked and anadromous species.
BACKGROUND
Salmon is one of the most widely consumed seafoods in Japan and many other countries around the world. Due to the confirmed cases of salmon-induced allergy, the food sanitation law in Japan stipulates salmon as one of the specific food items for which labeling is recommended when used as an ingredient of processed foods. However, trout, the landlocked form of anadromous salmon, is not subject to the allergen-labeling requirements, even though both populations belong to a single species. Since no supporting data have been demonstrated to make a clear distinction between these two populations in terms of allergenicity, we comparatively examined their allergenic properties using sera from patients allergic to fish.


METHODS
Extracts of Oncorhynchus nerka from different habitats were obtained: kokanee (landlocked) and red salmon (anadromous). Control extracts were derived from four other species. This study focused on the (1) IgE-binding capacity of the fish extracts in patients' sera (n = 50), (2) ELISA inhibition test (n = 6), and (3) inhibition immunoblot test (n = 8) between the kokanee and red salmon.


RESULTS
The extracts from kokanee and red salmon showed the highest correlation with each other in terms of the IgE-binding capacity, and showed complete (100%) reciprocal cross-inhibition in the ELISA inhibition test. On immunoblotting, there was no marked difference in the staining pattern between the two extracts, and each IgE-binding band gradually disappeared when the patients' sera were preincubated with the counterpart antigen in a dose-dependent manner.


CONCLUSIONS
These results suggest that kokanee has similar allergenic properties to red salmon.
Kondo
Yasuto
Y
Department of Pediatrics, Fujita Health University, Toyoake, Aichi, Japan. ykondo@fujita-hu.ac.jp
Ahn
Jeakun
J
Komatsubara
Ryo
R
Terada
Akihiko
A
Yasuda
Toshitaka
T
Tsuge
Ikuya
I
Urisu
Atsuo
A
D000485:Allergens / Q000276:immunology; D000818:Animals; D000941:Antigens / Q000276:immunology*; D001667:Binding, Competitive / Q000276:immunology; D015153:Blotting, Western; D002648:Child; D002675:Child, Preschool; D045424:Complex Mixtures / Q000276:immunology; D003429:Cross Reactions / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005512:Food Hypersensitivity / Q000276:immunology*; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology*; D007223:Infant; D008297:Male; D017684:Oncorhynchus kisutch / Q000276:immunology; D017686:Oncorhynchus mykiss / Q000276:immunology; D010473:Perciformes / Q000276:immunology; D012474:Salmon / Q000145:classification / Q000276:immunology*; D014413:Tuna / Q000276:immunology
D000485:Allergens; D000941:Antigens; D045424:Complex Mixtures; D007073:Immunoglobulin E