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Background Understanding consumers’ interpretation of allergy information is crucial for effective food safety policies. We evaluated consumer understanding of allergy information on foods in controlled, experimental studies. Method Using 18 packaged foods, we evaluated consumer understanding of information about allergens in two experiments: First, a comparison of foods with no stated allergen versus allergen as a stated ingredient versus a precautionary allergen label (PAL); second, a comparison of three common variants of PAL. In each experiment, consumers with and without self‐reported food allergy were asked to estimate the risk of allergic reaction and to rate the comprehensibility of the allergen information. In the second experiment, consumers were also asked which form of PAL they preferred. Results Risk of reaction was assessed as high and low for foods with the allergen stated as ingredient, or without any mention of allergen. However, risk assessment for PAL varied and was judged as higher by non‐allergic than allergic participants (82% vs. 58%, p, Food labels are a crucial source of information for allergic consumers, but despite ingredient declaration legislation, allergic reactions frequently occur. We evaluated common allergy information on foods in two controlled experimental studies. Allergic consumers attribute lower risks to products with PAL than consumers without FA, different risks are attributed to different PAL wordings especially by consumers with higher levels of Health Literacy, and less than 50% of participants judge allergy information to be clear. Better allergy information is called for.

Background. Soy is globally recognized as a commonly allergenic food. The VITAL (Voluntary Incidental Trace Allergen Labeling) Scientific Expert Panel (VSEP) of the Allergen Bureau of Australia & New Zealand used data on minimal reactive doses in low-dose clinical challenges of soy-allergic individuals to elaborate and propose the first Reference Dose for soy at 1.0 mg soy protein (based on the lower 95% confidence interval of the ED05) in 2014 to guide use of precautionary allergen labeling (PAL). These data were taken from clinical challenges with soy flour or soy-based infant formula. More recently, the VSEP has examined additional data including data from challenges conducted with soy milk and used a new statistical model averaging approach to propose a new Reference Dose for soy at 0.5 mg soy protein (based on the ED01). Questions have arisen about the lowering of the soy Reference Dose and the appropriate use of this new Reference Dose in risk management for soy residues especially relating to the adventitious presence of soy in other grains, legumes and pulses emanating from agricultural comingling. Scope and approach. Several factors may have contributed to the lowering of the Reference Dose for soy including the use of the ED01 vs. the previous use of the 95% lower confidence interval of the ED05, the use of model averaging and multiple parametric statistical models, and the incorporation of additional data including the soy milk challenge data. Soy milk may differ from other forms of soy as a challenge material. The background data were examined in greater detail in an attempt to unravel the causative factor(s) behind the lowering of the soy Reference Dose. The use of the new soy Reference Dose for allergen management of the adventitious presence of soy in other agricultural crops was examined in terms of risk to soy-allergic consumers. Key finding and conclusions. The Reference Dose for soy in VITAL 3.0 decreased to 0.5 mg soy protein primarily because it was based on the ED01 rather than the 95% lower confidence interval of the ED05. Clinical data suggest that some soy-allergic individuals may react to soy milk but can tolerate soy flour and other soy-based foods. Perhaps, soy milk may be a more potent form of soy because of its minimal processing. But, with the current data available, there is no evidence to conclude that soy milk responders as a whole group display a relevantly different ED-distribution. The new soy Reference Dose impacts risk assessments for agricultural comingling, a form of cross contact that can be challenging to control on a national or international basis. The potential risks posed by agricultural comingling should be carefully examined in light of the new Reference Dose for soy protein.

The prevalence of IgE-mediated food allergy diagnosed by clinical history and positive serology in adults across Europe ranges from 0.3-6% (1). Almost half of the food allergic adults are confronted with accidental allergic reactions yearly (2). Especially moderate and severe reactions require medical consultation and treatment, which can have a high impact on economic costs (3).

Background: Cow’s milk (CM) is an increasingly common cause of severe allergic reactions, but there is uncertainty with respect to severity of reactions at low level CM exposure, as well as the reproducibility of reaction thresholds. Objective: To undertake an individual participant data (IPD) meta-analysis of studies reporting double-blind, placebo-controlled food challenges (DBPCFC) in CM, to determine the rate of anaphylaxis to low level exposures and the reproducibility of reaction thresholds. Methods: Systematic review and individual participant data (IPD) meta-analysis of studies reporting relevant data. Authors were contacted to provide additional data and/or clarifications as needed. Risk of bias was assessed using the National Institute for Clinical Excellence methodological checklists. Results: 34 studies were included, representing data from over 1000 participants. The cumulative ED01 and ED05 (cumulative doses causing objective symptoms in 1% and 5% of the at-risk allergic population) were 0.3 (95%CI 0.2-0.5) and 2.9 (95%CI 1.6-5.4) mg, respectively. At meta-analysis, 4.8% (95%CI 2.0-10.9%) and 4.8% (95%CI 0.7-27.1%) of individuals reacting to ≤5mg and ≤0.5mg of CM protein (respectively) had anaphylaxis (minimal heterogeneity, I 2 =0%). 110 individuals subsequently underwent a repeat DBPCFC: the intra-individual variation in reaction threshold was limited to a ½-log change in 80% (95%CI 65-89%) of participants. Two individuals initially tolerated 5mg CM protein but then reacted to this dose at a subsequent challenge, although neither had anaphylaxis. Conclusions: Around 5% of CM-allergic individuals reacting to an ED01 or ED05 exposure might have anaphylaxis to that dose. This equates to 5 and 24 anaphylaxis events per 10,000 patients exposed to an ED01 or ED05 dose respectively, in the broader CM-allergic population. The vast majority of these anaphylactic reactions would be at the more mild end of the spectrum of anaphylaxis severity, responding to single dose of epinephrine.

Regional and national legislation mandates the disclosure of “priority” allergens when present as an ingredient in foods, but this does not extend to the unintended presence of allergens due to shared production facilities. This has resulted in a proliferation of precautionary allergen (“may contain”) labels (PAL) that are frequently ignored by food-allergic consumers. Attempts have been made to improve allergen risk management to better inform the use of PAL, but a lack of consensus has led to variety of regulatory approaches and nonuniformity in the use of PAL by food businesses. One potential solution would be to establish internationally agreed “reference doses,” below which no PAL would be needed. However, if reference doses are to be used to inform the need for PAL, then it is essential to characterize the hazard associated with these low-level exposures. For peanut, there are now published data relating to over 3000 double-blind, placebo-controlled challenges in allergic individuals, but a similar level of evidence is lacking for other priority allergens. We present the results of a rapid evidence assessment and meta-analysis for the risk of anaphylaxis to a low-level allergen exposure for priority allergens. On the basis of this analysis, we propose that peanut can and should be considered an exemplar allergen for the hazard characterization at a low-level allergen exposure. Resumen: La legislación regional y nacional exige la divulgación de alérgenos "prioritarios" cuando están presentes como ingrediente en los alimentos, pero esto no se extiende a la presencia involuntaria de alérgenos debido a instalaciones de producción compartidas. Esto ha dado lugar a una proliferación de etiquetas de precaución para alérgenos ("pueden contener") (PAL) que los consumidores alérgicos a los alimentos suelen ignorar. Se han hecho intentos para mejorar la gestión del riesgo de alérgenos para informar mejor el uso de PAL, pero la falta de consenso ha llevado a una variedad de enfoques regulatorios y a la falta de uniformidad en el uso de PAL por parte de las empresas alimentarias. Una posible solución sería establecer “dosis de referencia” acordadas internacionalmente, por debajo de las cuales no se necesitaría PAL. Sin embargo, si se van a utilizar dosis de referencia para informar la necesidad de PAL, entonces es esencial caracterizar el peligro asociado con estas exposiciones de bajo nivel. Para el maní, ahora hay datos publicados relacionados con más de 3000 desafíos doble ciego controlados por placebo en individuos alérgicos, pero falta un nivel similar de evidencia para otros alérgenos prioritarios. Presentamos los resultados de una evaluación rápida de la evidencia y un metanálisis del riesgo deanafilaxia a una exposición a alérgenos de bajo nivel para alérgenos prioritarios. Sobre la base de este análisis, proponemos que el cacahuete puede y debe considerarse un alérgeno ejemplar para la caracterización del peligro en una exposición a un alérgeno de bajo nivel. Instituto de Investigación de Tecnología de Alimentos Fil: Turner, Paul J. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido. Fil: Patel, Nandinee. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido. Fil: Ballmer-Weber, Barbara K. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido. Fil: Ballmer-Weber, Barbara K. Clínica de Dermatología y Alergología. Kantonsspital; Suiza. Fil: Baumert, Joe L. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido. Fil: Blom, W. Marty. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido. Fil: Brooke-Taylor, Simon. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido. Fil: Brough, Helen. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido. Fil: Brough, Helen. King's College London. Departamento de Alergia Pediátrica; Reino Unido. Fil: Campbell, Dianne E. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido. Fil: Campbell, Dianne E. Tecnologías DBV. Montrouge; Francia. Fil: Chen, Hongbing. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido. Fil: Chinthrajah, R. Sharon. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido. Fil: Crevel, René W.R. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido. Fil: Dubois, Anthony E.J. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido. Fil: Ebisawa, Motohiro. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido. Fil: Elizur, Arnon. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido. Fil: Elizur, Arnon. Universidad de Tel Aviv. Facultad de Medicina Sackler. Departamento de Pediatría; Israel. Fil: Gerdts, Jennifer D. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido. Fil: Gowland, M. Hazel. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido. Fil: Houben, Geert F. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido. Fil: Hourihane, Jonathan O.B. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido. Fil: Knulst, André C. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido. Fil: La Vieille, Sébastien. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido. Fil: López, María Cristina. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido. Fil: Mills, E.N. Clare. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido. Fil: Polenta, Gustavo Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Investigación Tecnología de Alimentos; Argentina. Fil: Polenta, Gustavo Alberto. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido. Fil: Purington, Natasha. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido. Fil: Said, María. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido. Fil: Sampson, Hugh A. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido. Fil: Sampson, Hugh A. Escuela de Medicina Icahn. División de Alergia e Inmunología Pediátricasen. Nueva York. Estados Unidos de América. Fil: Schnadt, Sabine. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido. Fil: Södergren, Eva. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido. Fil: Södergren, Eva. ThermoFisher Scientific; Suecia. Fil: Taylor, Stephen L. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido. Fil: Remington, Benjamin C. Imperial College London. Instituto Nacional del Corazón y los Pulmones; Reino Unido. Fil: Remington, Benjamin C. Grupo BV. Consultoría Remington; Holanda.

Background: Food allergies are a significant public health issue, and the only effective management option currently available is strict avoidance of all foods containing the allergen. In view of the practical impossibility of limiting risks to zero, quantitative allergen risk assessment and management strategies are needed. Objective: We sought to develop appropriate methods for informing population-based risk assessments and risk management programs to benefit all stakeholders but particularly patients with food allergy. Methods: Individual thresholds for food allergens (maximum tolerable doses and minimum eliciting doses) can ideally be established through double-blind, placebo-controlled food challenges. If double-blind, placebo-controlled food challenge data are not available, data from widely used open food challenges using predefined objective criteria can also provide useful data regarding minimum eliciting doses. For more than 20 years, the Netherlands Organisation for Applied Scientific Research and the Food Allergy Research and Resource Program at the University of Nebraska-Lincoln have been collecting individual maximum tolerable doses and minimum eliciting doses that produce objective symptoms from published and unpublished clinical data to better refine knowledge regarding the sensitivity of the population to food allergens. Results: In this article we provide in-depth insights into the methodology applied by the Netherlands Organisation for Applied Scientific Research and Food Allergy Research and Resource Program to derive individual maximum tolerable doses and minimum eliciting doses for objective symptoms from clinical food challenge data. More than 90 examples for determining individual allergic thresholds are presented. Conclusion: With the methodology presented in this article, we aim to stimulate harmonization and transparency in quantitative food allergen risk assessment and risk management programs, encouraging their wider adoption. © 2019 American Academy of Allergy, Asthma & Immunology

Food allergy is a major public health concern with avoidance of the trigger food(s) being central to management by the patient. Food information legislation mandates the declaration of allergenic ingredients; however, the labelling of the unintentional presence of allergens is less defined. Precautionary allergen labelling (PAL) was introduced by the food industry to help manage and communicate the risk of reaction from the unintended presence of allergens in foods. In its current form, PAL is counterproductive for consumers with food allergies as there is no standardised approach to applying PAL. Foods with a PAL often do not contain the identified food allergen while some products without a PAL contain quantities of common food allergens that are capable of inducing an allergic reaction. Integrated Approaches to Food Allergen and Allergy Risk Management (iFAAM) was an EU-funded project that aimed to improve the management of food allergens by the food industry for the benefit of people with food allergies. Within iFAAM, a clinically validated tiered risk assessment approach for food allergens was developed. Two cross-stakeholder iFAAM workshops were held on 13th -14th December 2016 and 19th -20th April 2018. One of the objectives of these workshops was to develop a proposal to make PAL effective for consumers. This paper describes the outcomes from these workshops. This provides the basis for the development of more informative and transparent labelling that will ultimately improve management and well-being in consumers with food allergy. This article is protected by copyright. All rights reserved.

Access to Eliciting Doses (ED) for allergens enables advanced food allergen risk assessment. Previously, the full ED range for 14 allergenic foods, including milk, and recommendations for their use were provided (Houben et al., 2020). Additional food challenge studies with cow's milk-allergic patients added 247 data points to the original dataset. Using the Stacked Model Averaging statistical method for interval-censored data on the 697 individual NOAELs and LOAELs for milk generated an updated full ED distribution. The ED01 and ED05, the doses at which 1% and 5% of the milk-allergic population would be predicted to experience any objective allergic reaction, were 0.3 and 3.2 mg milk protein for the discrete and 0.4 mg and 4.3 mg milk protein for the cumulative dose distribution, respectively. These values are slightly higher but remain within the 95% confidence interval of previously published EDs. We recommend using the updated EDs for future characterization of risks of exposure of milk-allergic individuals to milk protein. This paper contributes to the discussion on the Reference Dose for milk in the recent Ad hoc Joint FAO/WHO Expert Consultation on Risk Assessment of Food Allergens. It will also benefit harmonization of food allergen risk assessment and risk management globally.

Unintentional intake of allergens through food products poses a daily risk for allergic patients. Models estimating the risk of reactions mostly use intake data from general population surveys. Our study evaluates the comparability of food intake levels in the general population to those in the food allergic population. Data were collected by a 24-h recall method on 2 non-consecutive days in 38 cow's milk and/or hen's egg and 35 peanut and/or tree nut allergic adult patients. All products were assigned to food groups previously developed for allergen risk assessment. Food intake distributions from the allergic populations and a matched sample from the Dutch National Food Consumption Survey were compared, and risk assessments were performed. Food intake data was obtained for 92% of the food groups. Comparison of the intake showed no statistically significant differences between either of the two allergic populations and the general population. Consequently, only small variations in estimated risks were found, that would not result in different risk management decisions. In conclusion, food intake data from the general population can be used for food allergen risk assessment and will not lead to a relevant under- or overestimation of the risk for the food allergic population.

Allergic reactions to meals consumed outside the home are common and can be severe and sometimes fatal.To quantify the risk reduction potentially achieved by increasing an individual's threshold sensitivity to peanut (such as by means of immunotherapy) in scenarios of peanut exposure through shared kitchen materials in a restaurant setting.Three versions of popular peanut-containing sauces were selected to represent common ingredients used in Asian cooking. Different combinations of utensils, equipment, sauces, and test conditions were prepared by a professional chef, with or without common cleaning procedures, to represent normal daily practice. Residue amounts of peanut-containing material on kitchen equipment and utensils were measured and used for quantitative risk assessment to model the risk reduction associated with increasing an individual's threshold.Shared utensils had mean residue amounts of 23 to 1519 mg peanut protein (no cleaning) and 3 to 82 mg peanut protein (after water rinse). Shared woks and pans had up to 20 mg peanut protein after rinsing. Individuals who reach a threshold of 300 mg peanut protein have a predicted relative risk reduction of 94.9% to greater than 99.99% with brief cleaning. With no cleaning, relative risk reductions were 63.5% to 91.1% for individuals with a baseline threshold of less than or equal to 100 mg peanut protein who reach a threshold of 300 mg peanut protein, increasing to 91% to 99.7% when reaching a threshold value of 1000 mg peanut protein.In all shared kitchen material scenarios that we studied, achieving an eliciting dose of 300 or 1000 mg peanut protein seems clinically relevant for the peanut-allergic population.

Refined vegetable oils including refined peanut oil are widely used in foods. Due to shared production processes, refined non-peanut vegetable oils can contain residual peanut proteins. We estimated the predicted number of allergic reactions to residual peanut proteins using probabilistic risk assessment applied to several scenarios involving food products made with vegetable oils. Variables considered were: a) the estimated production scale of refined peanut oil, b) estimated cross-contact between refined vegetable oils during production, c) the proportion of fat in representative food products and d) the peanut protein concentration in refined peanut oil. For all products examined the predicted risk of objective allergic reactions in peanut-allergic users of the food products was extremely low. The number of predicted reactions ranged depending on the model from a high of 3 per 1000 eating occasions (Weibull) to no reactions (LogNormal). Significantly, all reactions were predicted for allergen intakes well below the amounts reported for the most sensitive individual described in the clinical literature. We conclude that the health risk from cross-contact between vegetable oils and refined peanut oil is negligible. None of the food products would warrant precautionary labelling for peanut according to the VITAL® programme of the Allergen Bureau. © 2017 Elsevier Ltd

Background In food allergy, eliciting doses (EDs) of foods on a population level can improve risk management and labeling strategies for the food industry and regulatory authorities. Previously, data available for walnut were unsuitable to determine EDs. Objective The objective of this study was to determine EDs for walnut allergic adults and to compare with previously established threshold data for peanut and tree nuts. Methods Prospectively, adult subjects with a suspected walnut allergy underwent a low-dose double-blind, placebo-controlled food challenge. Individual no observed and lowest observed adverse effect levels were determined and log-normal, log-logistic, and Weibull models were fit to the data. Estimated ED values were calculated for the ED5, ED10, and ED50, the dose respectively predicted to provoke an allergic reaction in 5%, 10%, and 50% of the walnut allergic population. Results Fifty-seven subjects were challenged and 33 subjects were confirmed to be walnut allergic. Objective symptoms occurred in 20 of the positive challenges (61%). The cumulative EDs in the distribution models ranged from 3.1 to 4.1 mg for the ED05, from 10.6 to 14.6 mg walnut protein for the ED10, and from 590 to 625 mg of walnut protein for the ED50. Conclusions Our data indicate that population EDs for walnut are slightly higher compared with those for peanut and hazelnut allergy. Currently available data indicate that the ED values for hazelnut could be used as a conservative temporary placeholder when implementing risk management strategies for other tree nuts where little or no food challenge data are available.

Background Eliciting doses (EDs) (eg, ED01 or ED05 values, which are the amounts of allergen expected to cause objective symptoms in 1% and 5% of the population with an allergy, respectively) are increasingly being used to inform allergen labeling and clinical management. These values are generated from food challenge, but the frequency of anaphylaxis in response to these low levels of allergen exposure and their reproducibility are unknown. Objective Our aim was to determine (1) the rate of anaphylaxis in response to low-level peanut exposure and (2) the reproducibility of reaction thresholds (and anaphylaxis) at food challenge. Methods We conducted a systematic review and individual participant data meta-analysis of studies that reported at least 50 individuals with peanut allergy reacting to peanut at double-blind, placebo-controlled food challenge (DBPCFC) and were published between January 2010 and September 2020. Risk of bias was assessed by using National Institute for Clinical Excellence methodologic checklists. Results A total of 19 studies were included (covering a total of 3151 participants, 534 of whom subsequently underwent further peanut challenge). At individual participant data meta-analysis, 4.5% (95% CI, 1.9% to 10.1%) of individuals reacted to 5 mg or less of peanut protein with anaphylaxis (moderate heterogeneity [I2 = 57%]). Intraindividual thresholds varied by up to 3 logs, although this variation was limited to a half-log change in 71.2% (95% CI, 56.2% to 82.6%) of individuals. In all, 2.4% (95% CI, 1.1% to 5.0%) of patients initially tolerated 5 mg of peanut protein but then reacted to this dose at subsequent challenge (low heterogeneity [I2 = 16%]); none developed anaphylaxis. Conclusion Around 5% of individuals reacting to an ED01 or ED05 level of exposure to peanut might develop anaphylaxis in response to that dose. This equates to 1 and 6 anaphylaxis events per 2500 patients exposed to an ED01 or ED05 dose, respectively, in the broader population of individuals with peanut allergy., Graphical abstract

Allergenic food particles (typically ~0.5–5 mm) may unintentionally end up in food products during production and can pose a risk for the allergic consumer. A single particle can provoke allergic symptoms in an allergic consumer when the dose of allergenic protein exceeds minimal eliciting doses. However, there is a lack of fundamental knowledge and research regarding allergenic particle behavior in food production and the resulting probability of their unintended presence in food products. In this study, the behavior of various types of particles encompassing a range of sizes and shapes (i.e. mustard seeds, sesame seeds, hazelnut pieces, walnut pieces and decoration pearls) was observed under controlled laboratory conditions and in a food production test facility. The main behavioral endpoints studied were rebound height and distance from and distribution around the rebound point. We found that the most determining particle characteristic for behavior was particle shape (spherical vs. non-spherical). In the laboratory, spherical mustard seeds showed an average rebound height of at least 3-fold higher than the non-spherical shaped sesame seeds, walnut pieces and hazelnut pieces. The distance from the rebound point after dropping was also considerably larger for mustard seeds, i.e. regularly up to 150 cm, while the majority of sesame seeds, walnut pieces and hazelnut pieces showed a distance from the rebound point of up to 30 cm, 7 cm and 4 cm, respectively. Experimental results from the test facility were in line with the results of the experiments in the laboratory, and provided additional insights in particle behavior for specific factory characteristics such as a moving belt. The experiments led to a concept for the definition of risk zones around a particle application and handling point, and can ultimately support efficient design of a production line and area and the application of tailored risk management measures with the goal to limit allergenic particle cross contamination.

National population-based food consumption surveys are used in food allergen risk assessment. It would be beneficial if food intake data is interchangeable between countries to bridge potential gaps present in national survey data, which is only possible when risk assessment outcomes for comparable food product groups between countries are fairly similar. Additionally, merged food intake data would enable risk assessments that cover scenarios for various countries, if based on the most critical situation. Therefore, we systematically compared risk assessment outcomes for a broad range of food groups based on United States and Dutch population food consumption survey data. We calculated risks for 14 allergenic foods for 9 concentrations (1-10,000 ppm) to assess comparability. Depending on the assumed allergen concentration, risk assessment outcomes for 20% (10 out of 49) food groups differed considerably. We consider the number of potentially relevant risk differences too high to conclude that food intake data from the US and The Netherlands can be used interchangeably. To allow risk assessments that cover scenarios for several countries, we recommend development and use of a food intake dataset based on the highest intake levels for each food group of the involved countries to facilitate risk management efforts and harmonization.

Introduction Involvement of cofactors, like physical exercise, alcohol consumption and use of several types of medication, are associated with more severe food allergic symptoms. However, there is limited evidence on how often cofactors play a role in food allergic reactions. The study aimed to get more insight into the frequency of exposure to cofactors and how often cofactors are associated with more severe symptoms in food allergic patients. Methods A questionnaire was completed by patients visiting the Allergology outpatient clinic. Patients with food allergy were included. Outcome measures were the frequency of medication use of medication groups that might act as cofactor and the frequency that physical exercise, alcohol consumption and use of analgesics are associated with more severe food allergic symptoms. Results Four hundred ninety-six patients were included in the study. The frequency with which patients used one or more types of medication that might act as cofactors was 7.7%: antacids/acid neutralizing medication (5%), NSAIDs (2%), beta blockers (0.6%), angiotensin-converting enzyme inhibitors (0.6%), and angiotensin receptor blockers (0.2%). Of all patients, 13% reported more severe symptoms to food after involvement of one or more of the cofactors: physical exercise (10%), alcohol consumption (5%), and use of analgesics (0.6%). Sixty-five percent did not know if these cofactors caused more severe symptoms; 22% reported that these cofactors had no effect. Conclusions Only a small percentage of patients (7.7%) used medication that might aggravate food allergic reactions. Physical exercise and alcohol consumption were the most frequently reported cofactors, but occurring still in only 10% or less.

Previously, we published selected Eliciting Dose (ED) values (i.e. ED01 and ED05 values) for 14 allergenic foods, predicted to elicit objective allergic symptoms in 1% and 5%, respectively, of the allergic population (Remington et al., 2020). These ED01 and ED05 values were specifically presented and discussed in the context of establishing Reference Doses for allergen management and the calculation of Action Levels for Precautionary Allergen Labeling (PAL). In the current paper, we publish the full range of ED values for these allergenic foods and provide recommendations for their use, specifically in the context of characterizing risks of concentrations of (unintended) allergenic proteins in food products. The data provided in this publication give risk assessors access to full population ED distribution information for 14 priority allergenic foods, based on the largest threshold database worldwide. The ED distributions were established using broad international consensus regarding suitable datapoints and methods for establishing individual patient's NOAELs and LOAELs and state of the art statistical modelling. Access to these ED data enables risk assessors to use this information for state-of-the-art food allergen risk assessment. This paper contributes to a harmonization of food allergen risk assessment and risk management and PAL practices.

Background Allergic reactions to meals consumed outside the home are common and can be severe and sometimes fatal. Objective To quantify the risk reduction potentially achieved by increasing an individual’s threshold sensitivity to peanut (such as by means of immunotherapy) in scenarios of peanut exposure through shared kitchen materials in a restaurant setting. Methods Three versions of popular peanut-containing sauces were selected to represent common ingredients used in Asian cooking. Different combinations of utensils, equipment, sauces, and test conditions were prepared by a professional chef, with or without common cleaning procedures, to represent normal daily practice. Residue amounts of peanut-containing material on kitchen equipment and utensils were measured and used for quantitative risk assessment to model the risk reduction associated with increasing an individual’s threshold. Results Shared utensils had mean residue amounts of 23 to 1519 mg peanut protein (no cleaning) and 3 to 82 mg peanut protein (after water rinse). Shared woks and pans had up to 20 mg peanut protein after rinsing. Individuals who reach a threshold of 300 mg peanut protein have a predicted relative risk reduction of 94.9% to greater than 99.99% with brief cleaning. With no cleaning, relative risk reductions were 63.5% to 91.1% for individuals with a baseline threshold of less than or equal to 100 mg peanut protein who reach a threshold of 300 mg peanut protein, increasing to 91% to 99.7% when reaching a threshold value of 1000 mg peanut protein. Conclusion In all shared kitchen material scenarios that we studied, achieving an eliciting dose of 300 or 1000 mg peanut protein seems clinically relevant for the peanut-allergic population.

Food allergy and allergen management are important global public health issues. In 2011, the first iteration of our allergen threshold database (ATDB) was established based on individual NOAELs and LOAELs from oral food challenge in roughly 1750 allergic individuals. Population minimal eliciting dose (EDp) distributions based on this dataset were published for 11 allergenic foods in 2014. Systematic data collection has continued (2011–2018) and the dataset now contains over 3400 data points. The current study provides new and updated EDp values for 14 allergenic foods and incorporates a newly developed Stacked Model Averaging statistical method for interval-censored data. ED01 and ED05 values, the doses at which 1%, and respectively 5%, of the respective allergic population would be predicted to experience any objective allergic reaction were determined. The 14 allergenic foods were cashew, celery, egg, fish, hazelnut, lupine, milk, mustard, peanut, sesame, shrimp (for crustacean shellfish), soy, walnut, and wheat. Updated ED01 estimates ranged between 0.03 mg for walnut protein and 26.2 mg for shrimp protein. ED05 estimates ranged between 0.4 mg for mustard protein and 280 mg for shrimp protein. The ED01 and ED05 values presented here are valuable in the risk assessment and subsequent risk management of allergenic foods. © 2020

Many food innovations rely on the introduction and use of new or modified proteins. New or modified food proteins may lead to major health risks due to their inherent potential to cause food allergy. Currently, the pre-market allergenicity assessment for new or modified food proteins and protein sources relies on methods for identifying allergenic hazards based on characteristics of known allergens. However, there is no general consensus on the allergenicity parameters to use and the criteria that should apply for the evaluation and decisions to be made. In this paper, we propose that the strategy for allergenicity risk assessment of new or modified food proteins and the methodologies applied should be governed by the risk management questions to be answered, reflected in the information needed by risk managers to enable their informed decision making. We generated an inventory of health outcome-related assessment parameters and criteria potentially important for risk management decision-making and we discuss the implications of selecting different optional criteria (e.g. cut-off values) for what could be accepted as safe with regards to the health outcomes in the (at risk) population. The impact of these various options on both method development and risk management practices was investigated. The work presented in this paper as well as the publication of it were part of and made possible by EU COST Action 1402 ImpARAS: Improving Allergy Risk Assessment Strategy for New Food Proteins (http://imparas.eu). Paula Alvito and Ricardo Assunção acknowledge the support from National Institute of Health, Dr. Ricardo Jorge and CESAM through the Fundação para a Ciência e a Tecnologia [UID/AMB/50017/2013], through national funds, and the co-funding by the FEDER [POCI-01- 0145-FEDER-00763], within the PT2020 Partnership info:eu-repo/semantics/publishedVersion

One of the input parameters in food allergy risk assessment is the amount of a given food consumed at an eating occasion. There is no consensus on how to use food consumption data when assessing the risk from unintended allergen presence in food products. A sensitivity analysis was performed to establish the optimal food consumption estimate for a deterministic food allergy risk assessment. Exposure was calculated for consumption percentiles (50th percentile, P50 to maximum) using the iFAAM consumption database in conjunction with an allergen concentration range from 1 to 1000 ppm. The resulting allergen intakes were compared to the allergic population reference doses proposed by Taylor et al. (2014) for 10 major allergenic foods. Optimal consumption percentiles were defined as those which predicted an intake below the relevant reference dose and met the defined acceptable risk level confirmed by probabilistic risk assessments. Analysis showed that, for 99% of the food groups, the P50 consumption met our criteria, while the P75 did so for 100% of the food groups. We suggest that the P75 is the optimal point estimate for use in deterministic food allergy risk assessment. It meets the safety objective and is adequately conservative for a public health context.

Background: Cofactors, such as physical exercise and alcohol intake, might be associated with the severity or occurrence of food allergic reactions. Objective: To gain insight into the frequency of presence of potential cofactors in accidental food allergic reactions in adults and to what extent these factors influence the severity and occurrence of allergic reactions. Methods: A prospective cohort study was conducted, with a 1-year follow-up in adult patients with a physician-diagnosed food allergy. Patients were required to fill in a questionnaire after every accidental allergic reactions to food over a 1-year period. The primary outcome measure was the frequency that potential cofactors were present in these allergic reactions. Results: A total of 157 patients were included, of which 46% reported a total of 153 reactions during a 1-year follow-up period. In 74% of the reactions, ≥1 potential cofactor was reported to be present: tiredness (38%), alcohol intake (16%), stress (14%), symptoms of pollinosis (16%), symptoms of asthma (9%), sickness/flu (3%), physical exercise (3%) and use of analgesics (2%). More than one potential cofactor was reported in almost half of all reactions (47%). There was no significant difference in the presence of these factors between mild, moderate and severe reactions (P = 0.522). In the total study population, 9% of the patients used medication that might act as cofactor (antacids, angiotensin receptor blockers [ARBs], beta blockers and angiotensin-converting enzyme inhibitors [ACEIs]) on a daily basis, which however did not influence the occurrence of reactions. Furthermore, 38% daily used allergy-suppressing medication. Conclusions: Although factors suggested to be cofactors were frequently present during accidental food allergic reactions, we found no evidence for an association between the potential cofactors examined and reaction severity, in a population where most reactions were of mild to moderate severity.

Highly refined peanut oil is considered to pose a risk to people with peanut allergy.[1] Although that risk has not been characterised, but controlled clinical challenges suggest it is negligible. A consequence is that the risk from cross contact between other refined vegetable oils and refined peanut oil during production must be assessed in order to assure consumer safety. Use of these refined vegetable oils in consumer food products potentially leads to very small amounts of peanut proteins in the final product. However, it is not clear yet if these amounts could reach levels that are relevant for public health. Allergen risk assessment using probabilistic techniques enables quantitative estimation of the risk after the consumption of a product that unintendedly contains an allergen. Several scenarios were defined for the unintended allergen levels in food products based on the estimated production scale of refined peanut oil in the UK, estimated figures for cross-contact and the peanut protein concentration in refined peanut oil. The consumption of 12 food products, selected for their high contribution to fat consumption including biscuits, margarine, ice cream and fried food, was combined with the peanut dose distribution. Food consumption data were derived from the National Diet and Nutrition Survey in the UK, and the Dutch National Food Consumption Survey. Peanut dosedistribution data were the same as used for the scientific review of VITAL® (Voluntary Incidental Trace Allergen Labelling).[2] We estimated that the amounts and distributions of peanut proteins posed a risk of objective allergic reactions in 0.03 to 0.6% of the peanut-allergic consumer population. The concentrations of peanut protein in selected food products would be below the limit of detection of current analytical methods and in all the scenarios examined, which included worst-case, the amounts consumed were below the VITAL reference dose for peanut. On that basis, the health risk is very small and none of those products would warrant precautionary labelling.

The spatio-temporal relationship between a decrease in the mitochondrial membrane potential (MMP) and externalization of phosphatidylserines (PS) during induction of apoptosis was investigated in single freshly isolated hepatocytes. Apoptosis was induced in the hepatocytes in three different ways: attack by activated Natural Killer cells, exposure to ATP, or exposure to the inhibitor of protein synthesis cycloheximide. Fluorescence microscopy showed staining of externalized PS at those areas where the staining for MMP was lost whereas in other areas the mitochondria remained intact for longer periods of time, indicating coupling between local loss of MMP and local PS exposure. To discriminate whether the decrease in MMP itself or a decrease in ATP induced PS externalization, hepatocytes were treated with rotenone, which resulted in a rapid collapse of cellular ATP but left the MMP intact for a much longer period. Addition of fructose prevented the decrease of ATP to approximately 30% and also delayed the collapse of the MMP. This indicates that ATP was needed for the maintenance of the MMP probably via reverse action of the ATP synthase. In a subsequent study hepatocytes were incubated with Natural Killer cells for induction of apoptosis followed by addition of rotenone to deplete ATP. Under these conditions the PS staining co-localized with mitochondrial MMP indicating that PS externalization does not require a collapse in MMP. Moreover, exposure of PS was evenly distributed over the whole plasma membrane. In conclusion, we propose that after an apoptotic stimulus some mitochondria start to loose their MMP, which results in cessation of ATP production and perhaps even consumption of ATP. This results in an overall decrease in cellular ATP. ATP-consuming enzyme reactions most distal from still intact mitochondria will be most sensitive to such a decrease. Apparently the translocase that keeps phosphatidylserines inward-oriented is such a sensitive enzyme.

Natural Killer cells are immune cells that recognize and eliminate altered and non-self cells from the circulation. To study the interaction between NK cells and target cells, we set up an experimental system consisting of rat Interleukin-2 activated Natural Killer cells (A-NK cells) and rat hepatocytes with a masked Major Histocompatibility Complex (MHC). The masking of the MHC induces recognition of the hepatocytes by the NK cells as non-self. We showed that in vitro apoptosis is rapidly induced in the hepatocytes [Blom et al., 1999] after co-incubation with A-NK cells. Now we describe the morphological changes that occur during and after interaction of A-NK cells with hepatocytes. Confocal laser scanning microscopy showed that the actin cytoskeleton of the NK cells was remodeled during attack of hepatocytes. Some NK cells were in close contact with the hepatocytes while others had formed actin-containing dendrites of varying length that made contact with the hepatocytes. However, dendrite formation is not obligatory for induction of apoptosis because cells that were unable to form these did induce FAS-dependent apoptosis in hepatocytes. Apparently both direct as well as distant contact resulted in apoptosis. Formation of the dendrites was calcium-dependent as EGTA largely prevented it. Importantly, chelation of the calcium also suppressed killing of the hepatocytes. Within 1 h after addition of the A-NK cells, morphological changes in hepatocytes that are characteristic of apoptosis, such as the formation of apoptotic bodies and fragmented nuclei, became apparent. Specifically, the actin cytoskeleton of the hepatocytes was remodeled resulting in the formation of the apoptotic bodies. Inhibition of caspase activity by z-Val-Ala-DL-Asp-fluoromethylketone (100 μM) partly protected against the rearrangement of the actin filaments in the hepatocytes. Cell Motil. Cytoskeleton 49:78–92, 2001. © 2001 Wiley-Liss, Inc.

The mechanism by which cycloheximide induces apoptosis in isolated rat hepatocytes was studied. Cycloheximide (1-300 microM) induced apoptosis within 3-4 hr in the hepatocytes. Specific apoptotic characteristics such as blebbing, phosphatidyl serine (PS) exposure, chromatin condensation, and nuclear fragmentation were induced. Cycloheximide (CHX) dose dependently activated the caspase-3-like proteases, but not the caspase-1-like proteases. Pretreatment of the hepatocytes with 100 microM of the caspase inhibitors z-Val-Ala-DL-Asp-fluoromethylketone or Ac-Asp-Glu-Val-Asp-aldehyde completely abrogated the caspase activation and the apoptosis. Addition of adenosine (100 microM) reduced phosphatidyl serine exposure and other morphological characteristics of apoptosis by 50%; however, it did not prevent the activation of the caspases, suggesting that adenosine inhibited downstream of caspase activation. The adenosine receptor antagonist 8-[4-[[[[(2-aminoethyl)amino]-carbonyl]methyl]oxy]phenyl]-1,3-dipropylxa nthine abolished the capacity of adenosine to prevent apoptosis, indicating that prevention was receptor-mediated. During apoptosis, the mitochondrial membrane potential in apoptotic cells (cells with PS exposition) was decreased to 50-60% of the control value; in the population viable cells, however, the mitochondrial membrane potential remained stable. Prevention of apoptosis by the caspase inhibitor z-Val-Ala-DL-Asp-fluoromethylketone or adenosine prevented the decrease in mitochondrial membrane potential. In conclusion, CHX rapidly induces apoptosis in isolated rat hepatocytes, which is inhibited by adenosine at a relatively late step.

Natural killer (NK) cells play a crucial role in the elimination of virus-infected or transformed cells in the liver. In this article, we describe the mechanism by which liver cells are killed by NK cells. Interleukin-2-activated natural killer (A-NK) cells from the rat induced apoptotic cell death in 30% of freshly isolated rat hepatocytes within 60 minutes. Recognition by the A-NK cells of the hepatocytes as nonself was established by masking the major histocompatibility complex (MHC) class I molecules on the hepatocytes with the OX18 antibody. During the killing process, a decrease of the mitochondrial membrane potential (MMP), formation of blebs, phosphatidyl serine (PS) externalization, chromatin condensation, and nuclear fragmentation were observed. The hepatocytes became apoptotic before permeabilization of the plasma membrane occurred, suggesting that the observed cytolysis was caused by secondary necrosis. The apoptotic process was completely abolished by the caspase inhibitors, Z-Val-Ala-DL-Asp fluormethylketone (zVAD-fmk) and Ac-Asp-Glu-Val-aldehyde (DEVD-cho). However, under these conditions, A-NK cells killed a smaller fraction of the hepatocytes by (primary) necrosis. These results indicate that apoptosis is the major cytotoxic process induced by A-NK cells in hepatocytes. If apoptosis is prevented, a more limited necrotic effect is induced. Therefore, this study shows that NK cells are fully equipped to induce both apoptosis and necrosis in hepatocytes, but appear to prefer the apoptotic route.

Food preferably has to be tasteful, healthy, attractive, and affordable, but should above all be safe. The safety of our daily food nowadays is at a reasonable level, but is far from obvious. During the past half century, food risk assessment and risk management approaches have developed. Yet, several white spots or areas of inefficiency still exist. In this chapter, recent and ongoing innovations in two areas are addressed: innovations in food allergy safety assessment and innovations in toxicological safety assessment of food. Regarding food allergy safety assessment, the development of risk assessment-based guidance on precautionary labeling is addressed as well as strategies for assessment of the allergenicity of novel food proteins, either from genetically modified (GM) or non-GM origin. Regarding the toxicological safety assessment of food, an innovative new toxicological safety assessment approach for complex food matrices based on the Threshold of Toxicological Concern concept is presented and discussed.

For most allergenic foods, limited availability of threshold dose information within the population restricts the advice on action levels of unintended allergenic foods which should trigger advisory labeling on packaged foods.The objective of this paper is to provide guidance for selecting an optimal sample size for threshold dosing studies for major allergenic foods and to identify factors influencing the accuracy of estimation. A simulation study was performed to evaluate the effects of sample size and dosing schemes on the accuracy of the threshold distribution curve. The relationships between sample size, dosing scheme and the employed statistical distribution on the one hand and accuracy of estimation on the other hand were obtained. It showed that the largest relative gains in accuracy are obtained when sample size increases from N= 20 to N= 60. Moreover, it showed that the EuroPrevall dosing scheme is a useful start, but that it may need revision for a specific allergen as more data become available, because a proper allocation of the dosing steps is important.The results may guide risk assessors in minimum sample sizes for new studies and in the allocation of proper dosing schemes for allergens in provocation studies. © 2014 Elsevier Ltd.

Background Children with cow’s milk allergy (CMA) need a cow’s milk protein (CMP) free diet to prevent allergic reactions. For this, reliable allergy-information on the label of food products is essential to avoid products containing the allergen. On the other hand, both overzealous labeling and misdiagnosis that result in unnecessary elimination diets, can lead to potentially hazardous health situations. Our objective was to evaluate if excluding CMA by double-blind placebo-controlled food challenge (DBPCFC) prevents unnecessary elimination diets in the long term. Secondly, to determine the minimum eliciting dose (MED) for an acute allergic reaction to CMP in DBPCFC positive children. Methods All children with suspected CMA under our care (Oct’05 - Jun’09) were prospectively enrolled in a DBPCFC. Placebo and verum feedings were administered on two randomly assigned separate days. The MED was determined by noting the ‘lowest observed adverse effect level’ (LOAEL) in DBPCFC-positive children. Based on the outcomes of the DBPCFC a dietary advice was given. Parents were contacted by phone several months later about the diet of their child. Results 116 children were available for analysis. In 76 children CMA was rejected. In 60 of them CMP was successfully reintroduced, in 2 the parents refused introduction, in another 3 the parents stopped reintroduction. In 9 children CMA symptoms reappeared. In 40 children CMA was confirmed. Infants aged ≤ 12 months in our study group have a higher cumulative distribution of MED than older children. Conclusions Excluding CMA by DBPCFC successfully stopped unnecessary elimination diets in the long term in most children. The MEDs form potential useful information for offering dietary advice to patients and their caretakers.

Background: For most allergenic foods, insufficient threshold dose information within the population restricts the advice on levels of unintended allergenic foods which should trigger precautionary labeling on prepackaged foods.Objective: We wanted to derive threshold dose distributions for major allergenic foods and to elaborate the protein doses at which a proportion of the allergic population is likely to respond.Methods: For 7 allergenic foods double-blind, placebo-controlled food challenges (DBPCFCs) with a positive outcome for allergic reactions were selected from the clinical database of children routinely tested to diagnose food allergy at the University Medical Center Groningen. For each allergen 2 population threshold distributions were determined with the individual minimal eliciting dose and the preceding dose of each DBPCFC for objective symptoms and any symptom (either subjective or objective).Results: Individual positive DBPCFCs were available for peanut (n = 135), cow's milk (n = 93), hen's egg (n = 53), hazelnut (n = 28), and cashew nut (n = 31). Fewer children were challenged with soy (n = 10) or walnut (n = 13). Threshold dose distributions showed a good statistical and visual fit. The protein dose at which 5% of the allergic population is likely to respond with objective reactions was 1.6 mg for peanut, 1.1 mg for cow's milk, 1.5 mg for hen's egg, 7.4 mg for cashew nut, and 0.29 mg for hazelnut. Thresholds for any symptom were on average 2 to 6 times lower than for objective symptoms. The 95% upper and lower confidence intervals of the threshold distributions were overlapping. The peanut threshold distribution on objective symptoms was similar to the distribution of another European center.Conclusions: Threshold distribution curves and eliciting doses are a powerful tool to compare different allergenic foods and for informing policy on precautionary labeling. (J Allergy Clin Immunol 2013;131:172-9.)

Real-time measurements of ambient concentrations of gas-phase ammonia (NH3) were performed in Barcelona (NE Spain) in summer between May and September 2011. Two measurement sites were selected: one in an urban background traffic-influenced area (UB) and the other in the historical city centre (CC). Levels of NH3 were higher at CC (5.6 ± 2.1 μg m−3 or 7.5 ± 2.8 ppbv) compared with UB (2.2 ± 1.0 μg m−3 or 2.9 ± 1.3 ppbv). This difference is attributed to the contribution from non-traffic sources such as waste containers, sewage systems, humans and open markets more dense in the densely populated historical city centre. Under high temperatures in summer these sources had the potential to increase the ambient levels of NH3 well above the urban-background-traffic-influenced UB measurement station. Measurements were used to assess major local emissions, sinks and diurnal evolution of NH3. The measured levels of NH3, especially high in the old city, may contribute to the high mean annual concentrations of secondary sulfate and nitrate measured in Barcelona compared with other cities in Spain affected by high traffic intensity. Ancillary measurements, including PM10, PM2.5, PM1 levels (Particulate Matter with aerodynamic diameter smaller than 10 μm, 2.5 μm, and 1 μm), gases and black carbon concentrations and meteorological data, were performed during the measurement campaign. The analysis of specific periods (3 special cases) during the campaign revealed that road traffic was a significant source of NH3. However, its effect was more evident at UB compared with CC where it was masked given the high levels of NH3 from non-traffic sources measured in the old city. The relationship between SO42− daily concentrations and gas-fraction ammonia (NH3/(NH3 + NH4+)) revealed that the gas-to-particle phase partitioning (volatilization or ammonium salts formation) also played an important role in the evolution of NH3 concentration in summer in Barcelona.

Natural Killer (NK) cells are important in the first response against viruses and tumours. Compounds that modulate human NK cell activity offer interesting prophylactic and therapeutic options, however, a systematic screening tool is lacking. Development of suitable NK cell lines or receptor-based assays is hindered by the highly complicated regulation of the different NK cell subsets by multiple receptors. Here, we describe a cell-based flowcytometric activity assay adapted to identify NK cell modulating compounds. Fresh human peripheral blood mononuclear cells (PBMC) were incubated with NK-sensitive K562 target cells labelled with 5-(6)-carboxyfluorescein succinimidyl ester, followed by DNA-labelling with propidium iodide to identify dead cells. The assay demonstrated a good performance with an average Z'-factor of 0.6 and over 95% of the assays fulfilled the quality criteria, suggesting that it is possible to use a complex system with two different cell types to screen compounds. A large number of (natural) compounds and extracts were tested and normalized to the positive control, Interleukin-2. Promising and less promising compounds were distinguished. Effectiveness of compounds was based on the augmentation of NK cell activity as well as the number of responding subjects. To conclude the assay is robust, reliable and can be used for functional screening of natural compounds modulating NK cell activity.

The "Big 8" food allergens consists of cow's milk, eggs, wheat, peanuts, tree nuts, soybeans, fish, and crustacean shellfish and account for ~90% of the allergic reactions to foods. During the scientific review of the VITAL® (Voluntary Incidental Trace Allergen Labelling) program, individual challenge data were gathered for the Big 8 food allergens (plus mustard, sesame and celery) and, where possible, population threshold distributions were calculated. The VITAL® review process yielded over 1800 individual minimal eliciting doses (MED) for these allergens. However, ~80% of the previously gathered threshold data was generated by only 4 allergens: peanut (~40%), milk (~20%), egg (~10%) and hazelnut (~10%). Furthermore, over 150 foods have been reported to cause allergic reactions and clear data gaps still exist. For example, data gathered on celery and fish were not sufficient to generate a population distribution, threshold data for cashew were only available in children. Minimal eliciting doses for less commonly allergenic foods provides valuable information to all food allergy stakeholders. This study examines the current publically available MED data for rice, kiwi, apple, peach, carrot, maize, tomato, and other less common allergenic foods. This study will also try to minimize the datagaps of the "Big 8" food allergens. Where possible, population based threshold distributions and ED-values are calculated. Potency data from the less common allergens are compared to previously gathered data on the Big 8 food allergens. Additionally, all data collected during this study regarding the potency of less common allergens will be incorporated into the continued development of a validated, predictive and accepted allergen risk assessment strategy for existing and new protein sources and new or modified protein (containing) products. The results from this study should enable government and food industry risk managers to make more informed decisions regarding less commonly allergic foods.

Previously, we showed that interleukin-2 activated Natural Killer cells (A-NK cells) in vitro rapidly induced apoptosis in freshly isolated rat hepatocytes (Blom et al., 1999. Hepatology 29 (3): 785-792) which was caused by a rapid decrease in the mitochondrial membrane potential and activation of caspases. In the present study we investigated the involvement of calpains in A-NK cell-induced apoptosis in isolated hepatocytes. When NK cells and hepatocytes were incubated in the presence of a calpain inhibitor the number of apoptotic cells decreased from 46 to 36%. However, more hepatocytes became necrotic (48 vs. 30%) as compared to the uninhibited situation. Inhibition of the calpains alone could not prevent the induction of the nuclear and cytoskeletal disruptions occurring in the hepatocytes. Inhibition of both calpains and caspases increased the number of necrotic cells as compared to incubation with a single inhibitor. However, the damage to the cytoskeleton of the surviving cells was completely inhibited. We conclude that calpains play a role in induction of apoptosis by NK cells. However, their role is limited as compared to caspases.

The presence and localisation of G-actin in various cell lines was studied using the highly G-actin specific, fluorescence-labelled vitamin D-binding protein. In various cell-types, pig kidney-derived cells (LLC-PK1), Chinese hamster ovary (CHO) cells, SV-40 transformed African green monkey kidney (COS) cells and human hepatoma (HepG2) cells, G-actin was only visible in the cytoplasm of interphase cells. However, in mitotic cells, depending on the mitotic phase, intense G-actin staining was found associated with the mitotic spindle (early mitosis) or overlapping the DNA-staining pattern (late mitosis). Also after heat shock (60-180 min at 43 degrees C), an intense nuclear staining of G-actin was observed. In LLC-PK1 cells, the increase of nuclear G-actin staining disappeared again after 24 h at 37 degrees C, but in COS, CHO and HepG2 cells, it was still present in the nucleus after 24 h at 37 degrees C, indicating that the process was not rapidly reversible in these cells; the increased nuclear G-actin was not associated with cell division. Comparison of the amount of G-actin present in the nucleus and in the cytosol before and after heat shock using Western blotting demonstrated that the total amount of G-actin in both nucleus and cytosol was unchanged after heat shock. This indicates that the increased G-actin staining is not a result of import of G-actin into the nucleus. These observations suggest a rearrangement of G-actin in the nucleus during both mitosis and heat shock, which may be due to changes in interaction of G-actin with chromosomes.

The availability of clinically established DBPCFC minimal eliciting doses determined in food-allergic individuals is increasing and previous work has shown these data can be used to determine population based reference doses for allergen risk management. Despite the large amount of data for peanut, milk, egg and hazelnut, EU and US public health authorities have not established population thresholds for any of the allergenic foods. In the absence of regulatory guidance regarding thresholds, food producers have attempted to manage risk through the widespread application of precautionary "may contain" labelling. In turn, food-allergic consumer quality-of-life has decreased and some food-allergic individuals are ignoring these advisory statements. This study aimed to assess the effects of the number of individual threshold doses and the dosing scheme intervals on the accuracy of estimates of population thresholds for allergenic foods. A simulation study was performed to evaluate the effects of sample size (N=20-750) and dosing scheme (derivatives of the EuroPrevall protocol) on the accuracy of the resulting threshold distribution curve. The simulations were based on clinical data on individual subject thresholds from peanut, egg and soy flour allergic individuals. The relationships between sample size, dosing scheme and the employed statistical distribution on the one hand and the accuracy of estimation of population based eliciting doses on the other hand were obtained. The largest relative gains in accuracy were seen when sample size increases from N=20 to N=60. Additionally, proper allocation of the dosing steps is important. So, while the EuroPrevall dosing scheme is a good start, the scheme may need revision for a specific allergen as more data become available. These results may guide risk assessors in determining minimum sample sizes for new studies and in the allocation of proper dosing schemes for allergens in provocation studies. In turn, these results will help determine dataset requirements when establishing population thresholds and reference doses leading to improved allergen risk management of food products.