IgE Cross-reactivity between Fish Roe (Salmon, Herring and Pollock) and Chicken Egg in Patients Anaphylactic to Salmon Roe

ABSTRACTBackground: Salmon roe (SR) anaphylaxis has often been reported and SR-containing foods are designated as 'recommended for allergic labeling' ; however, there have been no reports about its allergenicity, including its cross-reactivity. Because its cross-reactivity is controversial, clinicians are often confused concerning education regarding its dietary elimination. The purpose of this study was to examine the cross-reactivity between SR and other kinds of fish roe, salmon, or chicken egg (CE).Methods: We measured the specific-lgE to SR, herring roe (HR), pollock roe (PR), salmon and CE using RAST in 27 patients with a fish allergy and 26 control subjects. Then, using the sera of 2 patients with SR anaphylaxis, an ELlSA inhibition study was performed to examine the cross-reactivity between SR and HR, PR, salmon or CE. We then compared the IgE binding patterns to SR between the anaphylaxis patients and fish allergy patients with immunoblotting.Results: There were positive correlations between SR and HR or PR, but none between SR and salmon or CE. In the ELISA study using sera from two patients with SR anaphylaxis, IgE-binding to SR was inhibited more than 50% only when the sera were pre-incubated with HR, inhibited almost 50% by PR in a dose-dependent manner, but not inhibited by CE or anisakis. Salmon inhibited the IgE binding to SR more than 50% in a SR- anaphylaxis patient. The IgE binding patterns to SR from anaphylaxis patients were almost identical and unlike those of patients with fish allergy.Conclusions: There was a cross-reactivity between SR and HR, but no relationship between SR and CE

Evaluation of oral immunotherapy efficacy and safety by maintenance dose dependency: A multicenter randomized study

Background Generally, oral immunotherapy (OIT) aims for daily administration. Recently, the efficacy of treatment with OIT at a low dose has been reported. However, the optimal dose and the evaluation of dose-dependent OIT outcome have not been described. Methods A multicenter, parallel, open-labeled, prospective, non-placebo controlled, randomized study enrolled 101 Japanese patients for treatment with OIT. We hypothesized that target dose OIT would induce short-term unresponsiveness (StU) earlier than reduced dose OIT. StU was defined as no response to 6200 mg whole egg, 3400 mg milk, and 2600 mg wheat protein, as evaluated by oral food challenge after 2-week ingestion cessation. To compare the two doses of OIT efficacy, the maximum ingestion doses during the maintenance phase of OIT were divided into 100%-dose or 25%-dose groups against their target StU dose, respectively. A total of 51 patients were assigned to the 100%-dose group [hen's egg (HE) = 26, cow's milk (CM) = 13, wheat = 12] and 50 to the 25%-dose group (HE = 25, CM = 13, wheat = 12). Primary outcome was established by comparing StU at 1 year. Secondary outcome was StU at 2 years and established by comparing allergic symptoms and immunological changes. Results The year 1 StU rates (%) for the 100%- and 25%-dose groups were 26.9 vs. 20.0 (HE), 7.7 vs. 15.4 (CM), and 50.0 vs. 16.7 (wheat), respectively. The year 2 StU rates were 30.8 vs. 36.0 (HE), 7.7 vs. 23.1 (CM), and 58.3 vs. 58.3 (wheat), respectively. There were no statistically significant differences in StU between years 1 and 2. The total allergic symptom rate in the 25%-dose group was lower than that in the 100%-dose group for egg, milk, and wheat. Antigen-specific IgE levels for egg-white, milk, and wheat decreased at 12 months. Conclusions Reduced maintenance dose of egg OIT showed similar therapeutic efficacy to the target dose. However, we were not able to clearly demonstrate the efficacy, particularly for milk and wheat. Reducing the maintenance dose for eggs, milk, and wheat may effectively lower the symptoms associated with their consumption compared to the target OIT dose. Furthermore, aggressive reduction of the maintenance dose might be important for milk and wheat, compared to the 25%-dose OIT

Defective IL-10 signaling in hyper-IgE syndrome results in impaired generation of tolerogenic dendritic cells and induced regulatory T cells

Dendritic cells from patients with hyper-IgE syndrome less efficiently generate induced regulatory T cells

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 allergenlabeling 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

Grades of 43 Fish Species in Japan Based on IgE-binding Activity

Background: Hypersensitivity reactions to fish are a common food allergy, but IgE-binding activity to fish species have not been fully elucidated. The aim of this study was to identify fish with high binding activity to IgE in sera from Japanese fish-hypersensitive individuals. Methods: 38 children with a history of at least one episode of hypersensitivity after ingestion of fish were enrolled and 34 children with no history of reactions and negative IgE results for at least five kinds of fish antigen were included as controls. Using a radioallergosorbent test, we examined IgE-binding to each fish species using sera from fish-hypersensitive subjects. Fish were then graded according to IgE-binding activity. Results: Many fish species, including red salmon, silver salmon, yellowfin tuna, big eyed tuna, Atlantic tuna, saurel, skipper, yellowtail, Japanese sardine, bonita and mackerel had high IgE-binding activity. All of these fish are abundantly consumed in Japan. The hypersensitivity reactions experienced by many subjects occurred after ingestion of species with high IgE-binding activity. Only halibut (Osteichthyes) and sharks (Chondrichthyes) had low IgE-binding activity. Conclusions: A correlation was observed between IgE levels and expression of symptoms after fish ingestion. High consumption of salmon, tuna, scad (including saurel), skipper, yellowtail, sardine, bonita and mackerel in Japan might be the cause of the high IgE-binding activity of these species. The grades of fish species consumed widely in Japan are likely to be useful for nutritional instruction of fish-allergic patients