Digestion of peanut allergens Ara h 1, Ara h 2, Ara h 3, and Ara h 6: a comparative in vitro study and partial characterization of digestion-resistant peptides.

Scope: There are differences in stability to pepsin between the major allergens in peanut; however, data are from different reports using different digestion models. This study provides a comprehensive comparison of the digestibility of the major peanut allergens.

Methods And Results: Peanut allergens Ara h 1, Ara h 2, Ara h 3 and Ara h 6 were incubated with pepsin to mimic the effect of gastric digestion.

Detection of walnut residues in foods using an enzyme-linked immunosorbent assay.

Tree nuts, including walnuts, can be responsible for allergic reactions. Food manufacturers have the responsibility to declare the presence of walnuts on packaged foods even when trace residues may be present from the use of shared equipment or the adventitious contamination of ingredients. The aim of this study was to develop a rapid, sensitive, and specific enzyme-linked immunosorbent assay (ELISA) method for the detection of walnut protein residues.

Clinical relevance of sensitization to lupine in peanut-sensitized adults.

Background: The use of lupine in food has been increasing during the last decade and allergic reactions to lupine have been reported, especially in peanut-allergic patients. The frequency and the degree of cross-reactivity to other legumes are not known. The aim of the study was to investigate the frequency of sensitization to lupine, and in addition to pea and soy, and its clinical relevance, in peanut-sensitized patients.

Sandwich enzyme-linked immunosorbent assay (ELISA) for the detection of lupine residues in foods.

Lupine has been increasingly used in food applications due to its high nutritional value and excellent functional properties. However, lupine provokes allergic reactions in susceptible individuals. The presence of undeclared lupine residues in foods can pose a serious health risk to lupine-allergic individuals.

Sandwich enzyme-linked immunosorbent assay (ELISA) for detection of mustard in foods.

Undeclared mustard residues in food products could trigger allergic reactions in mustard-allergic consumers. Our objective was to develop and validate a sandwich-type ELISA for the detection of mustard residues in foods. A mixture of yellow, brown, and oriental mustard seeds was used to immunize 3 rabbits and 1 sheep.

Lupine allergy: not simply cross-reactivity with peanut or soy.

Background: Reports of lupine allergy are increasing as its use in food products increases. Lupine allergy might be the consequence of cross-reactivity after sensitization to peanut or other legumes or de novo sensitization. Lupine allergens have not been completely characterized.

Consumer attitudes and risks associated with packaged foods having advisory labeling regarding the presence of peanuts.

Background: Foods with advisory labeling (eg, "may contain") are increasingly prevalent. Consumers with food allergies might ignore advisory labeling advice.

Objective: We sought to determine whether consumers with food allergy heeded advisory labels and whether products with advisory labels contained detectable peanut allergen.

Hazard characterisation in food allergen risk assessment: the application of statistical approaches and the use of clinical data.

A structured approach to assess the risk to allergic individuals from food allergens requires as a first step the experimental measurement of minimum eliciting doses in a population that is as representative as possible of the relevant allergic population, using a standardised protocol. These doses are established in controlled challenge studies, but logistical and statistical constraints mean that a proportion of the allergic population may still be at risk of reacting at doses below those which have been or could feasibly be tested. However, statistical modelling of the dose distribution resulting from such challenges permits inferences to be drawn about the proportion of allergic individuals that are likely to react to specified (low) amounts of residual allergen in food.

Does skin prick test reactivity to purified allergens correlate with clinical severity of peanut allergy?

Background: Recognition of specific peanut allergens or the diversity of IgE binding to peanut allergens may play a role in the elicitation of severe allergic reactions.

Objective: To investigate whether sensitization to individual allergens Ara h 1, Ara h 2, Ara h 3 and Ara h 6 is correlated with clinical severity.

Methods: The reactivity of purified peanut allergens was measured by skin prick test (SPT) and by IgE immunoblot in 30 patients.

Detecting fish parvalbumin with commercial mouse monoclonal anti-frog parvalbumin IgG.

Parvalbumin is a calcium-binding muscle protein that is highly conserved across fish species and amphibians. It is the major cross-reactive allergen associated with both fish and frog allergy. We used two-dimensional electrophoretic and immunoblotting techniques to investigate the utility of a commercial monoclonal anti-frog parvalbumin IgG for detecting parvalbumin present in some commonly consumed fish species.

Food allergen labeling in the USA and Europe.

Purpose Of Review: The ingredient statement on the label of packaged foods is an important source of information for food-allergic consumers. New legislation in the USA and European Union will increase the amount of information available to food-allergic consumers.

Recent Findings: The USA has implemented the Food Allergen Labeling & Consumer Protection Act, which mandates use of clear labeling and source labeling of ingredients derived from commonly allergenic sources.

Determination of no-observed-adverse-effect levels and eliciting doses in a representative group of peanut-sensitized children.

Background: Current labeling practices for allergenic foods like peanut can be inadequate. For future regulatory and industry guidelines, information on no-observed-adverse-effect levels (NOAELs) and eliciting doses (EDs) for allergenic foods is necessary.

Objective: To determine NOAEL and ED in a representative group of peanut-sensitized children, relate these data to history and sensitization, and evaluate the outcome of dietary management.

Cloning of oleosin, a putative new hazelnut allergen, using a hazelnut cDNA library.

The clinical presentation of non-pollen related allergy to hazelnut can be severe and systemic. So far, only a limited number of non-pollen related hazelnut allergens have been identified and characterized. The aim of this study was to identify and clone new hazelnut allergens.

Gaining perspective on the allergenicity assessment of genetically modified food crops.

Genetically modified plants are created by the insertion of foreign genes into plant cells followed by the generation of reproductively stable stock plants for rapid and precise improvements in agricultural crops. Current products provide resistance to insect pests, plant viruses or herbicides. Future products include nutritionally enhanced crops, salt and draught tolerant crops and plant produced industrial enzymes or pharmaceuticals.

IgE binding to pepsin-digested food extracts.

Background: Pepsin resistance of allergens like lipid transfer protein and 2S albumin has been suggested as explanation for the severity of symptoms often induced by these allergens. Component-resolved diagnosis with purified labile and stable allergens has therefore been proposed to better characterize the risk involved in a positive in vitro IgE test. However, for many foods, purified allergens are not (yet) available.

In silico methods for evaluating human allergenicity to novel proteins: International Bioinformatics Workshop Meeting Report, 23-24 February 2005.

The ILSI Health and Environmental Sciences Institute (HESI) hosted an expert workshop 22-24 February 2005 in Mallorca, Spain, to review the state-of-the-science for conducting a sequence homology/bioinformatics evaluation in the context of a comprehensive allergenicity assessment for novel proteins, to obtain consensus on the value and role of bioinformatics in evaluating novel proteins, and to discuss the utility and methods of allergen-specific IgE testing in the diagnosis of food allergy. The workshop participants included over forty international experts from academia, industry, and government. The workshop was hosted by the HESI Protein Allergenicity Technical committee, which has established a long-term program whose mission is to advance the scientific understanding of the relevant parameters for characterizing the allergenic potential of novel proteins.

Proteolytic processing of the peanut allergen Ara h 3.

The allergen Ara h 3 has been purified recently from peanuts. In contrast to recombinant Ara h 3, a 60 kDa single-chain polypeptide, the allergen isolated from its native source is extensively proteolytically processed. The characteristic proteolytic processing for 11S plant storage proteins of the glycinin family is observed for Ara h 3 yielding an acidic and a basic subunit, bound by a disulfide bridge.

Assessing genetically modified crops to minimize the risk of increased food allergy: a review.

The first genetically modified (GM) crops approved for food use (tomato and soybean) were evaluated for safety by the United States Food and Drug Administration prior to commercial production. Among other factors, those products and all additional GM crops that have been grown commercially have been evaluated for potential increases in allergenic properties using methods that are consistent with the current understanding of food allergens and knowledge regarding the prediction of allergenic activity. Although there have been refinements, the key aspects of the evaluation have not changed.

Purification and immunoglobulin E-binding properties of peanut allergen Ara h 6: evidence for cross-reactivity with Ara h 2.

Background: IgE-binding peanut proteins smaller than 15 kDa were previously identified as potential allergens in the majority of our peanut allergic population.

Objective: To characterize the novel allergen in order to determine whether it was similar to one of the thus far identified recombinant peanut allergens (Ara h 1-7).

Methods: An IgE-binding protein of <15 kDa was purified and identified via N-terminal sequencing.

A novel approach for the detection of potentially hazardous pepsin stable hazelnut proteins as contaminants in chocolate-based food.

Contamination of food products with pepsin resistant allergens is generally believed to be a serious threat to patients with severe food allergy. A sandwich type enzyme-linked immunosorbent assay (ELISA) was developed to measure pepsin resistant hazelnut protein in food products. Capturing and detecting rabbit antibodies were raised against pepsin-digested hazelnut and untreated hazelnut protein, respectively.

Detection of soy proteins in processed foods: literature overview and new experimental work.

Several tests for the detection of soy proteins in foods have been described in the literature, and some are commercially available. This article gives an overview of these methods and discusses the advantages and disadvantages of each individual method. Based on the conclusions of this inventory, an experimental approach was designed to improve the sensitivity of measuring soy protein in processed foods.

Reversible denaturation of Brazil nut 2S albumin (Ber e1) and implication of structural destabilization on digestion by pepsin.

The high resistance of Brazil nut 2S albumin, previously identified as an allergen, against proteolysis by pepsin was examined in this work. Although the denaturation temperature of this protein exceeds the 110 degrees C at neutral pH, at low pH a fully reversible thermal denaturation was observed at approximately 82 degrees C. The poor digestibility of the protein by pepsin illustrates the tight globular packing.

Ara h 8, a Bet v 1-homologous allergen from peanut, is a major allergen in patients with combined birch pollen and peanut allergy.

Background: We recently described patients with soybean allergy mainly mediated by cross-reactivity to birch pollen allergens. A majority of those patients were reported to have peanut allergy.

Objective: We sought to study the occurrence of peanut allergy in patients allergic to birch pollen and characterized the Bet v 1-homologous peanut allergen Ara h 8.