Component‐resolved Diagnosis of IgE‐mediated Fish Allergy with Grass Carp Allergens: 782

Abstract

Nicki YH. Leung, Christine YY. Wai, Agnes Sze Yin Leung, Gary WK. Wong, MD, and Ting Fan Leung, MD FRCPCH FAAAAI; Department of Pediatrics, The Chinese University of Hong Kong, Hong Kong, Hong Kong, Chinese University of Hong Kong, Shatin, Hong Kong. RATIONALE: Grass carp is a commonly consumed fish species in Hong Kong and Southern China. We investigated the utility of grass carp allergens for diagnosing IgE-mediated fish allergy in Chinese children. METHODS: IgE reactivity against parvalbumin, enolase and aldolase of grass carp were measured by enzyme-linked immunosorbent assay in 76 pediatrics subjects with clinical history of IgE-mediated fish allergy. IgE titers against these grass carp allergens were compared with IgE reactivity to cod extract and recombinant cod parvalbumin rGad c 1 as measured by ImmunoCAP, which is the conventional surrogate for fish allergy diagnosis. RESULTS: Grass carp parvalbuminwas found to be the dominant allergen in our study population where IgE reactivity to this allergen was observed in over 80% of our subjects. In contrast, sensitization to enolase and aldolase were only observed in less than 20% of subjects and the IgE reactivity was generally low. IgE reactivity to grass carp parvalbumin was significantly higher than recombinant cod extract or cod parvalbumin rGad c 1. The former allergen demonstrated superior diagnostic sensitivity for fish allergy at the cut-off of 0.35 kUA/L. CONCLUSIONS: Grass carp parvalbumin is a better tool for fish allergy diagnosis in our population when compared to conventional cod extract or cod parvalbumin. The clinical relevance of grass carp enolase or aldolase remains dubious.[This study is funded by Innovation and Technology Fund (ITS/082/17) of Hong Kong SAR Government]