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Shellfish allergy represents a crucial public health problem, resulting in an urgent requirement for an accurate, simple, and reliable method to quantify shellfish allergens in the complex food system. Tropomyosin (TM) is known as the major allergen in shellfish. Herein, a novel switch-conversional ratiometric fluorescent biosensor, using TM-specific aptamer as the recognition probe, was developed to detect TM in the complex food system. The proposed aptasensor exhibited good accuracy, stability, and selectivity for the quantification of TM in foodstuffs. Furthermore, the applicability of this proposed aptasensor in complex food samples was verified using seven different shellfish samples. Therefore, this ratiometric fluorescent aptasensor enables accurately detecting the presence of TM traces in foods, providing technical support for allergen label supervision. • A EXPAR based-ratiometric aptasensor was developed to detect shellfish allergen TM. • TM could achieve the highly specific and accurate detection. • Applicability of proposed sensor in food samples was validated. [ABSTRACT FROM AUTHOR]

• SWATH-MS-based proteomics described the splenic and intestinal traits of tropomyosin allergy. • In the spleen, allergy is characterized by the upregulation of the Ig κ chain V-III region PC 7175. • In the intestine, allergy concurred with the downregulated expression of 35 proteins. • The downregulated proteins are involved in metabolic, absorption and wound-healing processes. Type-I food allergies are hypersensitive reactions compromising the immune organs and epithelial barriers. To investigate the organ-specific proteomic alterations of the allergy responses, the spleen and intestine of mice sensitized with high (shrimp and clam) and weak (fish) allergenic tropomyosins were analyzed using sequential windowed acquisition of all theoretical fragment ion mass spectra (SWATH-MS)-based proteomics. The results showed that Th1 and Th2 tropomyosin-induced responses in the spleen are characterized by the unique upregulation of innate (cochlin) and adaptive (Ig κ chain V-III region PC 7175) immune regulators, respectively. In the intestine, tropomyosin allergy concurred with the downregulation of 35 differentiating proteins featuring the overall impairment of metabolic pathways, absorption processes and ammonium ion responses. These data provide new functional biomarkers of tropomyosin-induced immune responses as well as candidate targets for intervention. [ABSTRACT FROM AUTHOR]

Highlights: [•] Arginine kinase (AK) from Scylla paramamosain was purified, cloned, and expressed. [•] The IgE epitopes of S. paramamosain AK were elucidated and identified. [•] The conformational IgE epitopes of S. paramamosain AK were the predominant epitopes. [ABSTRACT FROM AUTHOR]

Background: Recent studies suggest an increased prevalence of food-induced allergy and an increased incidence of food-related anaphylaxis. However, prevalence estimates of food allergies vary considerably between studies. Objectives: To determine the prevalence of peanut, tree nut, fish, shellfish, and sesame allergy in Canada. Methods: Using comparable methodology to Sicherer et al in the United States in 2002, we performed a cross-Canada, random telephone survey. Food allergy was defined as perceived (based on self-report), probable (based on convincing history or self-report of physician diagnosis), or confirmed (based on history and evidence of confirmatory tests). Results: Of 10,596 households surveyed in 2008 and 2009, 3666 responded (34.6% participation rate), of which 3613 completed the entire interview, representing 9667 individuals. The prevalence of perceived peanut allergy was 1.00% (95% CI, 0.80%-1.20%); tree nut, 1.22% (95% CI, 1.00%-1.44%); fish, 0.51% (95% CI, 0.37%-0.65%); shellfish, 1.60% (95% CI, 1.35%-1.86%); and sesame, 0.10% (95% CI, 0.04%-0.17%). The prevalence of probable allergy was 0.93% (95% CI, 0.74%-1.12%); 1.14% (95% CI, 0.92%-1.35%); 0.48% (95% CI, 0.34%-0.61%); 1.42% (95% CI, 1.18%-1.66%); and 0.09% (95% CI, 0.03%-0.15%), respectively. Because of the infrequency of confirmatory tests and the difficulty in obtaining results if performed, the prevalence of confirmed allergy was much lower. Conclusion: This is the first nationwide Canadian study to determine the prevalence of severe food allergies. Our results indicate disparities between perceived and confirmed food allergy that might contribute to the wide range of published prevalence estimates. [Copyright &y& Elsevier]

Abstract: Two types of murine monoclonal antibodies (MAbs) against American lobster (Homarus americanus) were generated and characterized. Three purified MAbs were characterized to be specific to the shellfish major allergen tropomyosin. MAbs 5G5E1 and 1A3A7 were reactive to tropomyosin from crustacean species only, whereas MAb 2A7H6 was reactive to both crustacean and mollusk tropomyosins. None of the antibodies reacted to vertebrate tropomyosins. Competitive ELISA indicated that the antigenic epitopes recognized by the two types of MAbs were different from each other. In addition, competitive immunoblot results showed that the binding of shellfish-allergic patient IgEs to lobster tropomyosin was inhibited by the MAb 2A7H6 only. This finding suggests that the antigenic epitope for the 2A7H6 antibody might be similar or close to the allergenic epitope shared by crustaceans and mollusks. Consequently, the MAbs recognizing the different common antigenic epiotopes obtained in the present study would not only facilitate the allergen characterization of shellfish, but may also be useful for the development of specific and sensitive immunoassays for allergen quantification or epitope mapping. [Copyright &y& Elsevier]

Background: There has been a substantial increase in the prevalence of peanut and tree nut allergy in Western populations in the last 2 decades. However, there is an impression that peanut and tree nut allergy is relatively uncommon in Asia. Objective: To evaluate the prevalence of peanut, tree nut, and shellfish allergy in schoolchildren in 2 Asian countries (Singapore and Philippines). Methods: A structured written questionnaire was administered to local and expatriate Singapore (4-6 and 14-16 years old) and Philippine (14-16 years old) schoolchildren. Results: A total of 25,692 schoolchildren responded to the survey (response rate, 74.2%). Of these, 23,425 responses fell within the study protocol''s 4 to 6 and 14 to 16 year age groups and were included in the analysis. The prevalence of convincing peanut and tree nut allergy were similar in both local Singapore (4-6 years, 0.64%, 0.28%; 14-16 years, 0.47%, 0.3%, respectively) and Philippine (14-16, 0.43%, 0.33%, respectively) schoolchildren, but was higher in the Singapore expatriates (4-6 years, 1.29%, 1.12%; 14-16 years, both 1.21%, respectively; 4-6 years, expatriates vs local Singaporeans: peanut, P = .019; tree nut, P = .0017; 14-16 years, P > .05). Conversely, shellfish allergy was more common in the local Singapore (4-6 years, 1.19%; 14-16 years, 5.23%) and Philippine (14-16 years, 5.12%) schoolchildren compared with expatriate children (4-6 years, 0.55%; 14-16 years, 0.96%; P < .001). When data were pooled, respondents born in Western countries were at higher risk of peanut (adjusted odds ratios [95% CIs]: 4-6 years, 3.47 [1.35-8.93]; 14-16 years, 5.56 [1.74-17.76]) and tree nut allergy (adjusted odds ratios [95% CIs]: 4-6 years, 10.40 [1.61-67.36]; 14-16 years, 3.53 [1.00-12.43]) compared with those born in Asia. Conclusion: This study substantiates the notion that peanut and tree nut allergy is relatively low in Asian children, and instead shellfish allergy predominates. Environmental factors that are yet to be defined are likely to contribute to these differences. [Copyright &y& Elsevier]