IgE reactivity to components of fish allergens in Pacific cod (Gadus macrocephalus) in atopic dogs

Background IgE reactivity to fish allergens in atopic dogs, which are used as models for food allergy, has not been elucidated to date. We investigated IgE reactivity to crude and purified Pacific cod (Gadus macrocephalus) allergens in atopic dogs to identify the allergenic components of cod. Methods Specific IgE to crude cod allergens in the sera of 179 atopic dogs, including 27 dogs with cod allergy, were measured using enzyme-linked immunosorbent assay (ELISA). The allergenic components of crude cod antigen were analyzed by ELISA, immunoblotting, and liquid chromatography-tandem mass spectrometry (LC-MS/MS). IgE reactivity to parvalbumin, collagen, and tropomyosin was evaluated using the sera of atopic dogs that were positive for specific IgE to crude cod allergens. Results Specific IgE to crude cod allergens were present in 36 (20%) of the 179 atopic dogs and 12 (44%) of the 27 dogs with cod allergy. In allergen component analysis, IgE reactivity to tropomyosin and enolase was observed in the sera of dogs with cod allergy. Among the 36 dogs with IgE reactivity to crude cod extracts, 9 (25%), 14 (39%), and 18 (50%) dogs had specific IgE to parvalbumin, collagen, and tropomyosin, respectively. Conclusions The dogs exhibited IgE reactivity to the cod allergen components similar to that observed in humans, providing support for the use of atopic dogs with fish allergy as a model for fish allergy in humans.