Differential patterns of fish sensitization in Asian populations:
implication for precision diagnosis
Abstract
Background The current diagnostics of fish allergy lack
sufficient accuracy such that more reliable tests such as
component-resolved diagnosis (CRD) are urgently needed. This study aimed
at identifying fish allergens of salmon and grass carp and evaluating
the sensitization pattern towards the identified allergens in fish
allergic subjects from two distinct populations in Asia.
Methods One hundred and three fish allergic subjects were
recruited from Hong Kong (67 subjects) and Japan (46 subjects). Western
blot and mass spectrometry were used to identify allergens from salmon
and grass carp. Fish allergens were purified and tested against 96 sera
on ELISA to analyze patients’ sensitization pattern. The protein
profiles of salmon meat prepared under different cooking methods until
core temperature reached 80°C were evaluated by SDS-PAGE and mass
spectrometry. Results Three common allergens between salmon and
grass carp, namely enolase, glycerldehyde-3-phosphate dehydrogenase
(GAPDH) and parvalbumin, and two salmon-specific allergens collagen and
aldolase were identified. Parvalbumin was the major allergen for both
fishes showing an overall sensitization rate of 74.7%, followed by
collagen (38.9%), aldolase (38.5%) and enolase (17.8%). Japanese
subjects showed more diverse allergen sensitization pattern and more
frequent IgE-binding to heat-labile salmon allergens. Compared with
steaming and boiling, cooking by baking and frying retained more fish
proteins inclusive of heat-labile allergens. Conclusions Fish
allergic patients from different Asian populations show varying fish
allergen sensitization profiles. The relevant extracts and components
for diagnosis are population-dependent but parvalbumin and collagen are
important biomarkers. Cooking methods modify allergen composition of
salmon and appear to influence patients’ allergic manifestations.