Isolation and characterization of proteic allergens in refined peanut oil

An unexpected allergic skin reaction to peppermint oil capsules

Peppermint oil capsules are prescribed to manage abdominal colic and distension, a common complaint in postcaesarean section patients. Arachis (peanut) oil is contained within one frequently prescribed peppermint formulation: Colpermin. This ingredient is contraindicated in patients with peanut and soya allergy; however, this is not stated in the side effects or contraindications section of the British National Formulary, or present on the medication packaging. A postpartum woman in her early 30s had an unexpected allergic reaction to the capsules, in the form of a generalised body rash, fortunately with no anaphylactic features. The patient reported the same reaction to soya in the past. After review of the patient's clinical and medication history, Colpermin capsules were thought to be responsible for the patient's symptoms. This case highlights the necessity for clearer documentation in prescribing formularies and on medication packaging to ensure patient safety.

EAACI Molecular Allergology User's Guide 2.0

Since the discovery of immunoglobulin E (IgE) as a mediator of allergic diseases in 1967, our knowledge about the immunological mechanisms of IgE-mediated allergies has remarkably increased. In addition to understanding the immune response and clinical symptoms, allergy diagnosis and management depend strongly on the precise identification of the elicitors of the IgE-mediated allergic reaction. In the past four decades, innovations in bioscience and technology have facilitated the identification and production of well-defined, highly pure molecules for component-resolved diagnosis (CRD), allowing a personalized diagnosis and management of the allergic disease for individual patients. The first edition of the "EAACI Molecular Allergology User's Guide" (MAUG) in 2016 rapidly became a key reference for clinicians, scientists, and interested readers with a background in allergology, immunology, biology, and medicine. Nevertheless, the field of molecular allergology is moving fast, and after 6 years, a new EAACI Taskforce was established to provide an updated document. The Molecular Allergology User's Guide 2.0 summarizes state-of-the-art information on allergen molecules, their clinical relevance, and their application in diagnostic algorithms for clinical practice. It is designed for both, clinicians and scientists, guiding health care professionals through the overwhelming list of different allergen molecules available for testing. Further, it provides diagnostic algorithms on the clinical relevance of allergenic molecules and gives an overview of their biology, the basic mechanisms of test formats, and the application of tests to measure allergen exposure.

Natural ingredients in cosmetic products-A suggestion for a screening series for skin allergy

BACKGROUND

Naturally derived cosmetic product ingredients of both plant and animal origin are being included increasingly in product formulations in order to cater to consumer preferences. They may be an overlooked cause of reactions to cosmetic products in some patients with dermatitis.

OBJECTIVES

To identify naturally derived cosmetic product ingredients with allergenic potential (type I and type IV) and propose a cosmetic screening test series.

METHODS

The study was conducted in two steps. The first step was a market survey using a nonprofit application helping consumers avoid problematic substances in cosmetic products. The application contained 10 067 cosmetic products that were label checked for naturally derived cosmetic product ingredients. The second step was a literature search to examine how frequently the naturally derived ingredients were described and related to allergic reactions in cosmetics or other topically administered products.

RESULTS

We identified 121 different naturally derived cosmetic product ingredients that were included in at least 30 cosmetic products. In total, 22 ingredients were selected for a screening test series.

CONCLUSIONS

We propose a supplemental patch test and a prick test screening series with naturally derived cosmetic product ingredients for patients with skin reactions to cosmetic products, aiming to identify a cause in more patients than is currently possible.

Safety Assessment of Avena sativa (Oat)-Derived Ingredients As Used in Cosmetics

This is a safety assessment of Avena sativa (oat)-derived ingredients. The reported functions of these ingredients in cosmetics include abrasives, antioxidant, skin conditioning agents, absorbents, and bulking agents. The Panel reviewed relevant animal and human data related to these ingredients. Because final product formulations may contain multiple botanicals, each containing the same constituents of concern, formulators are advised to be aware of these constituents and to avoid reaching levels that may lead to sensitization or other toxic effects. The Panel stated that industry should continue to use good manufacturing practices to limit impurities and concluded that all but one of the Avena sativa (oat)-derived ingredients are safe as cosmetic ingredients in the practices of use and concentration described in this safety assessment when formulated to be nonsensitizing; data are insufficient to come to a conclusion of safety for Avena Sativa (Oat) Meristem Cell Extract.

Epicutaneous Exposure to Peanut Oil Induces Systemic and Pulmonary Allergic Reaction in Mice

BACKGROUND

The prevalence of peanut allergy (PA) is constantly on the rise. Atopic dermatitis (AD) is a major risk factor for developing food allergy. Some bath oils and skin creams used for treating AD contain peanut oil, and it has been suggested that exposure to peanut allergens through a disrupted skin barrier is a potential cause of PA. Our aim was to investigate whether application of peanut oil to irritated skin causes a systemic or respiratory allergic response to peanuts in an animal model.

METHODS

BALB/c mice underwent epicutaneous sensitization with either peanut oil (PM, n = 9) or phosphate buffered solution (controls, n = 9) daily for 5 consecutive days. Ten days after the last exposure the mice were challenged with intranasal peanut protein for 5 consecutive days. Bronchial alveolar lavage fluid was collected for cellular studies and measurement of cytokine levels. Sera were collected for immunoglobulin E (IgE) measurement.

RESULTS

Epicutaneous peanut oil sensitization increased leukocyte and eosinophil counts and interleukin-13 levels (p = 0.003, p = 0.0006 and p = 0.03, respectively), in addition to increasing total serum IgE (p = 0.03).

CONCLUSIONS

The results suggest that topical application of peanut oil may play a role in the etiology of PA.

Lipophilic Allergens, Different Modes of Allergen-Lipid Interaction and Their Impact on Asthma and Allergy

Molecular allergology research has provided valuable information on the structure and function of single allergenic molecules. There are several allergens in food and inhalant allergen sources that are able to interact with lipid ligands via different structural features: hydrophobic pockets, hydrophobic cavities, or specialized domains. For only a few of these allergens information on their associated ligands is already available. Several of the allergens are clinically relevant, so that it is highly probable that the individual structural features with which they interact with lipids have a direct effect on their allergenic potential, and thus on allergy development. There is some evidence for a protective effect of lipids delaying the enzymatic digestion of the peanut (Arachis hypogaea) allergen Ara h 8 (hydrophobic pocket), probably allowing this molecule to get to the intestinal immune system intact (sensitization). Oleosins from different food allergen sources are part of lipid storage organelles and potential marker allergens for the severity of the allergic reaction. House dust mite (HDM), is more often associated with allergic asthma than other sources of inhalant allergens. In particular, lipid-associated allergens from Dermatophagoides pteronyssinus which are Der p 2, Der p 5, Der p 7, Der p 13, Der p 14, and Der p 21 have been reported to be associated with severe allergic reactions and respiratory symptoms such as asthma. The exact mechanism of interaction of these allergens with lipids still has to be elucidated. Apart from single allergens glycolipids have been shown to directly induce allergic inflammation. Several-in parts conflicting-data exist on the lipid (and allergen) and toll-like receptor interactions. For only few single allergens mechanistic studies were performed on their interaction with the air-liquid interface of the lungs, in particular with the surfactant components SP-A and SP-D. The increasing knowledge on protein-lipid-interaction for lipophilic and hydrophobic food and inhalant allergens on the basis of their particular structure, of their capacity to be integral part of membranes (like the oleosins), and their ability to interact with membranes, surfactant components, and transport lipids (like the lipid transfer proteins) are essential to eventually clarify allergy and asthma development.

Rapidly detecting major peanut allergen-Ara h2 in edible oils using a new immunomagnetic nanoparticle-based lateral flow assay

Ara h2 is a major peanut allergen that induces rashes, vomiting, diarrhea, and anaphylactic shock. Since peanut is a major source in producing edible oils globally, Ara h2 residues can be present in various edible oils. In this work, an immunomagnetic nanoparticle-based lateral flow assay for identifying Ara h2 in edible oils is developed. This assay exhibits high sensitivity with a visual detection limit of 0.1 mg/kg Ara h2 in oil, and favorable specificity in differentiating peanut from seeds and nuts. The calculated CV values of intra- and inter-assay were 6.73-10.21% and 4.75-8.57%, respectively, indicating high reproducibility. In an analysis of 26 oil products, Ara h2 was detected in two peanut oils as 0.122 ± 0.026 mg/kg and 0.247 ± 0.027 mg/kg. The entire method takes 5 h, including a 3.5-h sample preparation. Hence, this method has the potential to be an effective way to screen edible oils for Ara h2.

Safety Assessment of Plant-Derived Fatty Acid Oils

The Cosmetic Ingredient Review Expert Panel (Panel) assessed the safety of 244 plant-derived fatty acid oils as used in cosmetics. Oils are used in a wide variety of cosmetic products for their skin conditioning, occlusive, emollient, and moisturizing properties. Since many of these oils are edible, and their systemic toxicity potential is low, the review focused on potential dermal effects. The Panel concluded that the 244 plant-derived fatty acid oils are safe as used in cosmetics.

Food allergen labelling: "May contain" evidence from Malaysia

Food allergen labelling is mandatory and regulated whilst precautionary allergen labelling (PAL) remains voluntary in most countries. It is the aim of this study to identify the food allergens declared in food products sold in a developing country and to what extent food allergens and PAL are emphasised in the products. A total of 505 food and beverages (snacks, baked goods, confectionary, baby food, condiments & jams, beverages, powder & paste, instant food, chilled & frozen food and canned food) were evaluated in Malaysia. Soybean represents the largest group of food allergen declared in labels, followed by wheat and milk products. Thirteen variations of contains statement were found with "Contains [allergen(s)]" being the most common (55.02%). There were 22 different types of "may contain" statements with 'May contain traces of [allergen(s)]' being the most common advice labelling used (55.41%). Different font type or emphasis such as brackets (51.57%) and bold font (33.86%) were used to inform consumers about presence of allergens. The national regulations on food allergen labelling are then critically contrasted with other Asian countries and the EU Regulation No. 1169/2011, which represents one of the most stringent food regulations in the world. Improving current allergen labelling limitations and practices would be of great benefit to consumers to prevent risk of food hypersensitivity.

Relevance of Lipophilic Allergens in Food Allergy Diagnosis

PURPOSE OF REVIEW

The purpose of this review is to provide available data on a new class of allergens, the oleosins, and their diagnostic value. There is evidence that allergen extracts used for in vivo as well as in vitro diagnostic tests do not contain oleosins because these proteins are lipophilic and nearly insoluble in saline or aqueous solutions. So far, only oleosins of peanut, sesame and hazelnut have been registered as allergens. Reports on IgE-binding tests performed with oleosins of different species with sera from allergic patients show that IgE specific for oleosins are associated with severe allergic reactions which is why they should be part of the diagnostic tests in the future.

RECENT FINDINGS

Recent findings showed that oleosins purified from in shell-roasted peanuts revealed a higher IgE-binding capacity when compared to raw ones. Naturally purified as well as recombinantly produced peanut oleosins can be used in basophil activation test. The synopsis of all reports on different thermal processing of several oleosin sources and the respective data obtained with patients sera investigated via immunoblot and basophil activation test points to the recommendation that-if naturally purified oleosins are used, they should mostly be obtained from roasted food allergen sources. For immunoblot and basophil activation test, both, naturally purified oleosins as well as recombinant modified oleosins are valuable diagnostic tools.

Specific allergen profiles of peanut foods and diagnostic or therapeutic allergenic products

BACKGROUND

Generic immunoassays for peanut cannot discriminate between allergen levels in peanut-derived food products or therapeutics. Clinical trials of oral immunotherapy (OIT) are strengthened by using standardized peanut preparations with defined doses of major allergens.

OBJECTIVE

This article describes measurement of Ara h 1, Ara h 2, and Ara h 6 in peanut foods and in peanut flour extracts used for allergy diagnosis and OIT.

METHODS

Monoclonal antibody-based enzyme immunoassays for Ara h 1, Ara h 2, and Ara h 6 were used to compare allergen levels in peanut (n = 16) and tree nut (n = 16) butter, peanut flour (n = 11), oils (n = 8), extracts used for diagnosis and OIT (n = 5), and the National Institute for Standards and Technology Peanut Butter Standard Reference Material 2387.

RESULTS

Roasted peanut butters contained 991 to 21,406 μg/g Ara h 1 and exceeded Ara h 2 and Ara h 6 levels by 2- to 4-fold. Similarly, National Institute for Standards and Technology Peanut Butter Standard Reference Material 2387 contained 11,275 μg/g Ara h 1, 2,522 μg/g Ara h 2, and 2,036 μg/g Ara h 6. In contrast, peanut flours contained 787 to 14,631 μg/g Ara h 2 and exceeded Ara h 1 levels by 2- to 20-fold. Flour extracts used for OIT contained 394 to 505 μg/mL Ara h 1, 1,187 to 5,270 μg/mL Ara h 2, and 1,104 to 8,092 μg/mL Ara h 6. In most cases specific peanut allergens were not detected in tree nut butters or peanut oils.

CONCLUSIONS

The results show marked differences in specific peanut allergen profiles in peanut butter and flour and peanut preparations for clinical use. Roasting can increase Ara h 1 levels in peanut butter. Variability in allergen levels could affect the outcome of clinical trials of peanut OIT, especially with respect to Ara h 1. Specific allergen measurements will improve standardization and provide accurate dosing of peanut preparations that are being used for OIT.

IgE antibodies and skin tests in immediate hypersensitivity reactions to infliximab in inflammatory bowel disease: impact on infliximab retreatment

BACKGROUND

Infliximab (IFX) is used for the treatment of inflammatory bowel diseases (IBD). Immediate hypersensitivity reactions (HR) to IFX are frequently reported.

OBJECTIVES

We investigated immunoglobulin E (IgE)-mediated mechanisms underlying immediate HR to IFX. We also evaluated the clinical utility of allergological tests as well as the tolerability of IFX retreatment in these patients.

METHODS

This was a prospective single-center study including IBD patients with previous immediate HR to IFX. Skin tests to IFX, including prick tests and intradermal tests, and measurement of anti-IFX IgE antibodies were performed at least 4 weeks after HR. In case of negative skin tests and absence of IgE antibodies, readministration of IFX was performed with a twice-reduced infusion rate. In case of positive tests or recurrence of HR during readministration of IFX, a 12-step desensitization or induction of tolerance protocol was proposed.

RESULTS

A total of 24 IBD patients were included (Crohn's disease: n=20). Prick tests to IFX were all negative. Intradermal test was positive in one patient. Anti-IFX IgE antibodies were not detected in 21 patients and were detected in three patients (significant level in one patient and intermediate level in two patients). No relationship was observed between positive skin tests and the presence of anti-IFX IgE antibodies. Switch to adalimumab was well tolerated in 10/11 patients. The readministration of IFX was well tolerated in 4/11 patients. Desensitization to IFX was successful in three out of four patients.

CONCLUSION

The vast majority of immediate HR to IFX is not IgE-mediated. Allergological tests are of poor clinical utility. Desensitization or induction of tolerance protocol may allow continuation of IFX therapy in IBD patients with a history of immediate HR.

Development of a novel strategy to isolate lipophilic allergens (oleosins) from peanuts

Background

Peanut allergy is one of the most severe class I food allergies with increasing prevalence. Especially lipophilic allergens, such as oleosins, were found to be associated with severe symptoms, but are usually underrepresented in diagnostic extracts. Therefore, this study focused on isolation, molecular characterization and assessment of the allergenicity of peanut oleosins.

Methods and Results

A comprehensive method adapted for the isolation of peanut oil bodies of high purity was developed comprising a stepwise removal of seed storage proteins from oil bodies. Further separation of the oil body constituents, including the allergens Ara h 10, Ara h 11, the presumed allergen oleosin 3 and additional oleosin variants was achieved by a single run on a preparative electrophoresis cell. Protein identification realized by N-terminal sequencing, peptide mass fingerprinting and homology search revealed the presence of oleosins, steroleosins and a caleosin. Immunoblot analysis with sera of peanut-allergic individuals illustrated the IgE-binding capacity of peanut-derived oleosins.

Conclusion

Our method is a novel way to isolate all known immunologically distinct peanut oleosins simultaneously. Moreover, we were able to provide evidence for the allergenicity of oleosins and thus identified peanut oleosins as probable candidates for component-resolved allergy diagnosis.

Proteomic identification of allergenic seed proteins, napin and cruciferin, from cold-pressed rapeseed oils

In Finland and France atopic children commonly react to seeds of oilseed rape and turnip rape in skin prick tests (SPT) and open food challenges. These seeds are not as such in dietary use and therefore the routes of sensitization are unknown. Possible allergens were extracted from commercial cold-pressed and refined rapeseed oils and identified by gel-based tandem nanoflow liquid chromatography mass spectrometry (LC-MS/MS). Napin (a 2S albumin), earlier identified as a major allergen in the seeds of oilseed rape and turnip rape, and cruciferin (an 11S globulin), a new potential seed allergen, were detected in cold-pressed oils, but not in refined oils. Pooled sera from five children sensitized or allergic to oilseed rape and turnip rape seeds reacted to these proteins from cold-pressed oil preparations and individual sera from five children reacted to these proteins extracted from the seeds when examined with IgE immunoblotting. Hence cold-pressed rapeseed oil might be one possible route of sensitization for these allergens.

Determination of hidden hazelnut oil proteins in extra virgin olive oil by cold acetone precipitation followed by in-solution tryptic digestion and MALDI-TOF-MS analysis

Adulteration of extra-virgin olive oil (EVOO) with hazelnut oil (HO) is an illegal practice that could have severe health consequences for consumers due to the possible exposure to hidden hazelnut allergens. Here, matrix-assisted laser-desorption/ionization (MALDI) mass spectrometry (MS) was used as a rapid and sensitive technique for the detection of a low concentration of hazelnut proteins in oil samples. Different protocols were tested for protein extraction, and the most efficient (cold acetone) was applied to HO and EVOO adulterated with HO. The subsequent in-solution tryptic digestion of protein extracts and MALDI-MS analysis, using α-cyano-4-chlorocinnamic acid as matrix, allowed the detection of stable hazelnut peptide markers (i.e., the m/z ions 1002.52, 1356.71, 1394.70, 1440.81, 1453.85, 1555.76, 1629.83, 1363.73, and 1528.67) attributable to the main hazelnut proteins Cor a 9, Cor a 11, and Cor a 1. Thus, the approach might allow the direct detection of specific hazelnut allergens in EVOO at low concentration without time-consuming pretreatments.

Roasting and lipid binding provide allergenic and proteolytic stability to the peanut allergen Ara h 8

Abstract Ara h 8 is the peanut allergen homologous to the birch pollen allergen Bet v 1. Because Bet v 1 has been shown to bind lipophilic ligands, the aim of this investigation was to determine the impact of lipid binding and roasting on the Ara h 8 structure and their influences on allergenicity. For the characterization of natural Ara h 8 (nAra h 8) from roasted and unroasted peanuts, circular dichroism spectroscopy, hydrophobic binding assay, immunohistochemistry, and immunoblot with sera of peanut allergic patients were performed and compared with results from recombinant Ara h 8 (rAra h 8) and Bet v 1. rAra h 8 displayed stronger hydrophobicity than rBet v 1. Patients' sera showed IgE reactivity with rAra h 8 and nAra h 8 from roasted peanuts, whereas fewer sera recognized nAra h 8 from unroasted peanuts. Simulated gastric digestion experiments demonstrated low proteolytic stability of rAra h 8, whereas the stability of nAra h 8 was increasingly higher in unroasted and roasted peanuts. The results demonstrate that IgE reactivity and thermal and proteolytic stability are reinforced in nAra h 8 after roasting, most likely due to Maillard reactions, lipid oxidations, and lipophilic associations. These aspects must be considered when estimating the allergenicity of Bet v 1-homologous proteins.

Strategies to Mitigate Peanut Allergy: Production, Processing, Utilization, and Immunotherapy Considerations

Peanut (Arachis hypogaea L.) is an important crop grown worldwide for food and edible oil. The surge of peanut allergy in the past 25 years has profoundly impacted both affected individuals and the peanut and related food industries. In response, several strategies to mitigate peanut allergy have emerged to reduce/eliminate the allergenicity of peanuts or to better treat peanut-allergic individuals. In this review, we give an overview of peanut allergy, with a focus on peanut proteins, including the impact of thermal processing on peanut protein structure and detection in food matrices. We discuss several strategies currently being investigated to mitigate peanut allergy, including genetic engineering, novel processing strategies, and immunotherapy in terms of mechanisms, recent research, and limitations. All strategies are discussed with considerations for both peanut-allergic individuals and the numerous industries/government agencies involved throughout peanut production and utilization.

Identification of undeclared sources of animal origin in canine dry foods used in dietary elimination trials

Failure to respond to commercial limited antigen diets can occur in dogs kept on a dietary trial for the diagnosis of adverse food reaction (AFR). The aim of this study was to assess twelve canine dry limited antigen diets (eleven novel protein diets and one hydrolysed diet) for potential contamination by ingredients of animal origin not mentioned on the label. The validity of the two methods adopted for the detection of such food antigens was also evaluated. Each dietary product was analysed by microscopy analysis using the official method described in Commission Regulation EC 152/2009 with the aim of identifying bone fragments of different zoological classes (mammalian, avian and fish) and by polymerase chain reaction (PCR) for the identification of DNA of animal origin. Discrepancies between the results obtained by PCR and/or microscopy analysis and the ingredients listed on pet food packages were found. Only in two pet foods did the results of both analyses match the ingredients listed on the label. In the remaining ten samples, microscopy detected bone fragments from one or two unpredicted zoological classes, revealing avian fragments in six of ten samples followed by those of fish in five of ten and mammalian fragments in four of ten. In two samples, microscopy analysis identified a contamination that would have otherwise passed unobserved if only PCR had been used. However, PCR confirmed the presence of all the zoological classes detected by microscopy and also identified the DNA of an additional unexpected zoological class in two samples. Dogs might fail to respond to commercial limited antigen diets because such diets are contaminated with potential allergens. Both PCR and microscopy analysis are required to guarantee the absence of undeclared animal sources in pet foods. Before ruling out AFR, a novel protein home-made diet should be considered if the dog is unresponsive to a commercial regimen.

Quantification and partial characterization of the residual protein in fully and partially refined commercial soybean oils

A method has been developed to determine residual protein in refined oils, a potential trigger of allergic reactions. High-pH bicarbonate or borate buffers were found to be the most effective extractants, residual oil protein comprising a mixture of proteins of M(r) 6000-100000. Extracted protein could be quantified with superior precision using 3-(4-carboxybenzoyl)quinolone-2-carboxaldehyde (CBQCA). Residual protein content determined in a set of oils using the borate extraction-CBQCA assay was positively correlated with contents determined using a bicarbonate-total amino acid analysis method. Oil refining substantially reduced the oil protein content determined by the borate-CBQCA assay with neutralized/refined, bleached, and deodorized (fully refined) oils containing 62-265 ng/g oil, whereas crude un-degummed oils contained 86000-87900 ng/g of protein. These analyses and published data on cumulative threshold doses for soybean suggest that even the most sensitive individuals would need to consume at least 50 g of highly refined oil to experience subjective symptoms.

Are excipients really inert ingredients? A review of adverse reactions to excipients in oral dermatologic medications in Canada

BACKGROUND

Whereas several literature reviews have discussed the role of excipients in drug-related reactions, no article has focused specifically on those found in oral dermatologic medications.

METHODS

The Compendium of Pharmaceuticals and Specialties (CPS) was used to reference the inert ingredients found in oral dermatologic medications. An extensive literature review was subsequently conducted using PubMed and MEDLINE to document adverse reactions to these excipients.

RESULTS

Sixty-three oral dermatologic medications were reviewed. Lactose was commonly used as a filler. Several medications indicated that they were dye, tartrazine, or gluten free. Three medications were found to contain soybean oil and one was found to contain peanut oil.

CONCLUSIONS

Although there are documented reactions to excipients in other products in the literature, few reports outline reactions to excipients in oral dermatologic medications. Whether this low frequency is accurate or whether it is due to a lack of reporting remains unknown. If the latter reasoning is correct, dermatologists must be more aware of these possible reactions. This article serves as a reference guide for dermatologists to aid in prescribing medications to individuals with known sensitivities and to assist in working up patients with suspected reactions to inert ingredients.

Biosensor immunoassay for traces of hazelnut protein in olive oil

The fraudulent addition of hazelnut oil to more expensive olive oil not only causes economical loss but may also result in problems for allergic individuals as they may inadvertently be exposed to potentially allergenic hazelnut proteins. To improve consumer safety, a rapid and sensitive direct biosensor immunoassay, based on a highly specific monoclonal antibody, was developed to detect the presence of hazelnut proteins in olive oils. The sample preparation was easy (extraction with buffer); the assay time was fast (4.5 min only) and the limit of detection was low (0.08 microg/g of hazelnut proteins in olive oil). Recoveries obtained with an olive oil mixed with different amounts of a hazelnut protein containing hazelnut oil varied between 93% and 109%.

Safety of barley starch syrup in patients with allergy to cereals

It is not known whether trace amounts of proteins that may remain in cereal-starch-derived food ingredients even after food processing can trigger allergic symptoms in cereal-allergic individuals. The aim of this study was to find out if barley starch syrup causes allergic reactions in patients with allergy to wheat, barley, rye or oats. Fifteen children with allergy to these cereals, confirmed by double-blind placebo-controlled food challenge (DBPCFC), were selected for the study. When exposed to cereals, seven of the children (47%) showed immediate type reactions, such as urticaria, rash or anaphylaxis. Eight of the children (53%) showed delayed type reactions, such as deterioration of atopic dermatitis or diarrhoea. The fifteen children with allergy to cereals were exposed to barley starch syrup in DBPCFC and none of them showed any objective signs of allergy. On skin-prick tests (SPT), five of the children (33.3%) showed a positive (>or= 3 mm) reaction to at least one of the cereals but none of them to barley starch syrup. This study confirmed with 98% confidence that at least 90% of the patients with verified allergy to cereals will not react with allergic symptoms to barley starch syrup.

Analytic investigations on protein content in refined seed oils: implications in food allergy

BACKGROUND

A number of scientific reports have investigated the possible implications of refined seed oils in allergic reactions, resulting in conflicting points of view. Also the total amount of residual proteins after refinement is still a matter of debate. Nevertheless, seed oils are now blamed as possible cause of allergic reactions.

OBJECTIVE

To determine the true amount of proteins after oil refinement and to shed new lights on allergenic properties of refined seed oils.

METHODS

We optimized a protein extraction procedure on several commercial refined seed oils. Both colorimetric and amino acid analysis were used to measure residual protein content. SDS-PAGE was also used for characterizations of protein band patterns. Sensitized child patients sera were tested by Western blot on PAGE-resolved proteins.

RESULTS

Our extraction method proved to be effective and reproducible. Amino acid analysis resulted more accurate in determining the protein content with respect to colorimetric methods, indicating a higher protein content than that previously reported. IgE responsive residual proteins were found in peanut oil extracts.

CONCLUSIONS

Our preliminary data suggest that fully refined seed oils should be taken into account in the context of allergic reactions and would benefit of further toxicological studies.

A EuroPrevall review of factors affecting incidence of peanut allergy: priorities for research and policy

Peanuts are extensively cultivated around the world, providing a foodstuff that is both cheap to produce and nutritious. However, allergy to peanuts is of growing global concern, particularly given the severity of peanut-allergic reactions, which can include anaphylaxis and death. Consequently, it is important to understand the factors related to the prevalence of peanut allergy in order to inform efforts to ameliorate or pre-empt the condition. In this article we review evidence for the relevance of factors hypothesized to have some association with allergy prevalence, including both genetic and environmental factors. Although our analysis does indicate some empirical support for the importance of a number of factors, the key finding is that there are significant data gaps in the literature that undermine our ability to provide firm conclusions. We highlight these gaps, indicating questions that need to be addressed by future research.

Determination of proteins in refined and nonrefined oils

Five methods using aqueous/organic solvents for the separation of proteins from oils were compared. The extraction with acetone-hexane followed by amino acid analysis was found to be the most suitable method for isolation and quantification of proteins from oils. The detection limit of the method was 0.18 mg protein/kg oil, and the quantification limit was 0.6 mg protein/kg. The relative repeatability limit for samples containing 1-5 mg protein/kg sample was 27%. The protein recovery ranged between 68 and 133%. Using this method, the protein content of 14 refined and nonrefined oils was determined. In none of the refined oils were proteins detected, whereas the protein content of the unrefined oils ranged between undetectable in extra virgin olive oil to 11 mg/kg in rapeseed oil. With sodium dodecyl sulfate-polyacrylamide gel electrophoresis in combination with silver staining, many protein bands were visible in the unrefined soy, olive, peanut, and rapeseed oil samples. Proteins bands were not obtained from the refined fish oil. In the other refined oil samples, a few proteins bands could be visualized. Two protein bands with apparent molecular molecular masses of 58 and 64 kDa were always observed in these oils.

Naseptin® and peanut oil: a survey of practitioners' awareness in the UK

Objective:

The aim of this study was to determine how aware ENT practitioners are that Naseptin® (Alliance), widely used in ENT practice, contains peanut oil and to what extent this is conveyed to patients.

Methods:

A questionnaire was sent out to all ENT practitioners registered with the British Association of Otolaryngologists.

Result:

Analysis of the data confirmed that Naseptin cream is widely used in ENT practice and showed that although most practitioners are aware that Naseptin cream contains refined peanut oil (arachis oil) (74.3 per cent of consultants and 93.6 per cent of registrars) not all ask their patients whether they are allergic to peanuts (62.6 per cent of consultants and 87.3 per cent of registrars).

Conclusion:

The results suggest that more should be done to raise awareness amongst practitioners that Naseptin cream contains peanut oil and should be avoided in patients with a peanut allergy, as recommended by national guidelines. The use of Naseptin cream when contraindicated may have medicolegal implications.

Le régime d'éviction chez les allergiques à l'arachide

We analyzed, from the literature, the balance benefit/risk of a strict avoidance of peanut in children with peanut allergy. The benefits of a strict avoidance diet seem limited: reactions to the low doses and to the peanut oil refined are rare and most often slight. It is not proven that a strict avoidance facilitates the cure of allergy. On the other hand, strict avoidance could induce a worsening of allergy, with deterioration of quality of life, creation of food neophobia. In case of cure of allergy, it is difficult to normalize the diet after a strict avoidance. Outside of the rare sensitive patients to a very low dose of peanut, for which a strict avoidance is counseled, the report benefits risk is in favor of the prescription of adapted avoidance to the eliciting dose. For the majority of the peanut allergic children, it seems to us that the avoidance can and must be limited to the non hidden peanut.

Purification and cloning of two high molecular mass isoforms of peanut seed oleosin encoded by cDNAs of equal sizes

Oleosins are small plant proteins characterized by a long hydrophobic core flanked by amphipathic N- and C-terminal domains, which act as emulsifiers for the storage of lipids in seeds. They have been sequenced in a number of oilseeds important for the food industry but not in peanuts. We purified the major isoform of peanut oleosin by preparative electrophoresis with continuous elution, in sufficient amounts to raise specific antibodies, perform circular dichroism and N-sequence tryptic fragments. The structure of the purified oleosin was dominated by alpha-helix that may be assigned to the SDS-resistant central hydrophobic stretch. A two-step RT-PCR strategy was developed to determine the cDNA sequence of this oleosin. Two cDNA variants of equal sizes encoding for isoforms of 176 amino acids each were identified. The isoforms differed by seven amino acids mainly located in the N- and C-terminal domains. The corresponding mRNAs were estimated at 0.9 kb by Northern blot and were transcribed from genes without introns. Immunoprecipitation of the in vitro-translated peanut oleosin labeled with [14C]leucine or [35S]methionine produced the full-length protein (17 kDa) and a 6-kDa peptide corresponding to the N/C-terminal domains. This peptide was able to form SDS-PAGE stable oligomers by interacting with the full-length protein. A similar peptide was released after [125I]iodination of the purified oleosin that generated intermediate-sized oligomers also visible by Western blot on a crude oleosin extract. Oligomers reflect the natural ability of oleosins to strongly interact with each other via not only their central domains but also their N- and C-terminal domains.

Palacos and peanut allergy

Palacos cement contains peanut oil. The manufacturers instruction states that its use is contraindicated in patients allergic to peanuts. Awareness of this fact by orthopaedic surgeons was evaluated by postal questionnaire, which showed that 73% of those responding were not aware. However, on the basis of the available evidence in the literature, the clinical relevance of the manufacturers advice appears dubious. (Hip International 2004; 14: 254-7).

Thresholds of clinical reactivity to milk, egg, peanut and sesame in immunoglobulin E-dependent allergies: evaluation by double-blind or single-blind placebo-controlled oral challenges

BACKGROUND

The prevalence of food anaphylaxis due to masked allergens has increased within the last 10 years. Contamination of manufactured products by food allergens is a key concern for food industries.

OBJECTIVE

To determine quantities eliciting reactions in patients who have an IgE-dependent food allergy, thanks to standardized oral provocation tests. To evaluate the subsequent levels of sensitivity required for the detection tests of allergens for egg, peanut, milk and sesame.

METHODS

Prick-in-prick tests, Cap system RAST, and single or double-blind placebo-controlled food challenges (SBPCFC or DBPCFC) were performed. The doses of natural food were gradually increased from 5 to 5000 mg for solid food and from 1 to 30 mL for peanut oil, sunflower oil, soy oil and sesame oil.

RESULTS

Data from 125 positive oral challenges to egg, 103 to peanut, 59 to milk and 12 to sesame seeds were analysed. Haemodynamic modifications were observed in 2%, 3%, 1.7%, and 8% of the oral challenges (OCs) to egg, peanut, milk and sesame, respectively. Respiratory symptoms were observed in 12%, 20%, 10% and 42% of egg, peanut milk and sesame allergies, respectively. A cumulative reactive dose inferior or equal to 65 mg of solid food or 0.8 mL of milk characterized 16%, 18%, 5% and 8% of egg, peanut, milk and sesame allergies, respectively. 0.8% of egg allergies, 3.9% of peanut allergies, and 1.7% of milk allergies reacted to 10 mg or less of solid food or to 0.1 mL for milk. The lowest reactive threshold has been observed at less than 2 mg of egg; 5 mg of peanut, 0.1 mL of milk and 30 mg of sesame seed. Ten out of 29 OC with peanut oil, two out of two OC with soy oil and three out of six OC with sunflower oil were positive. Five out six OC with sesame oil were positive: 1 and 5 mL induced an anaphylactic shock.

CONCLUSION

The risk of asthma and anaphylactic shock to sesame and peanut is confirmed. Minimal reactive quantities show that, in order to guarantee a 95% safety for patients who are allergic to egg, peanut and milk, and on the basis of consumption of 100 g of food, the detection tests should ensure a sensitivity of 10 p.p.m. for egg, 24 p.p.m. for peanut and 30 p.p.m. for milk proteins. Oil allergies being considered, the limit of sensitivity should fall to 5 p.p.m.

Factors associated with the development of peanut allergy in childhood

BACKGROUND

The prevalence of peanut allergy appears to have increased in recent decades. Other than a family history of peanut allergy and the presence of atopy, there are no known risk factors.

METHODS

We used data from the Avon Longitudinal Study of Parents and Children, a geographically defined cohort study of 13,971 preschool children, to identify those with a convincing history of peanut allergy and the subgroup that reacted to a double-blind peanut challenge. We first prospectively collected data on the whole cohort and then collected detailed information retrospectively by interview from the parents of children with peanut reactions and of children from two groups of controls (a random sample from the cohort and a group of children whose mothers had a history of eczema and who had had eczema themselves in the first six months of life).

RESULTS

Forty-nine children had a history of peanut allergy; peanut allergy was confirmed by peanut challenge in 23 of 36 children tested. There was no evidence of prenatal sensitization from the maternal diet, and peanut-specific IgE was not detectable in the cord blood. Peanut allergy was independently associated with intake of soy milk or soy formula (odds ratio, 2.6; 95 percent confidence interval, 1.3 to 5.2), rash over joints and skin creases (odds ratio, 2.6; 95 percent confidence interval, 1.4 to 5.0), and oozing, crusted rash (odds ratio, 5.2; 95 percent confidence interval, 2.7 to 10.2). Analysis of interview data showed a significant independent relation of peanut allergy with the use of skin preparations containing peanut oil (odds ratio, 6.8; 95 percent confidence interval, 1.4 to 32.9).

CONCLUSIONS

Sensitization to peanut protein may occur in children through the application of peanut oil to inflamed skin. The association with soy protein could arise from cross-sensitization through common epitopes. Confirmation of these risk factors in future studies could lead to new strategies to prevent sensitization in infants who are at risk for subsequent peanut allergy.

The 18 kDa peanut oleosin is a candidate allergen for IgE-mediated reactions to peanuts

BACKGROUND

Peanut allergy is one of the five most frequent food allergies in children and in adults. Recently, we purified and evaluated the allergenicity of peanut oleosins, a family of small-sized proteins involved in the formation of peanut oil bodies.

METHODS

Allergenicity of the purified native protein and of the recombinant protein was tested by Western blot and by IgE-RIA.

RESULTS

We found IgE-binding with oleosin in 3 of 14 sera of patients who had suffered an allergic reaction to peanuts. Two sera reacted weakly against 16-18 kDa proteins corresponding to oleosin monomers, in Western blot. The main reacting bands had a molecular size estimated at approximately 34 kDa, approximately 50 kDa and approximately 68 kDa and could therefore correspond to oleosin oligomers. IgE reactivity was higher in extracts from roasted peanuts. The same phenomenon occurred with crude soybean oil fraction, with two bands of 16.5 and 24 kDa corresponding to monomers, and two bands of 50 kDa and 76 kDa corresponding to dimers and trimers, respectively. The 18 kDa band was observed in the 3 Western blots of a membrane-enriched fraction of recombinant oleosin produced in the Sf9-baculovirus expression system (performed with the 3 patient sera).

CONCLUSIONS

We have characterized a new peanut allergen which belongs to the oleosins, a family of proteins involved in the formation of oil bodies. The protein may be involved in some of the allergic cross-reactions to peanuts and soybeans.

IgE-binding and cross-reactivity of a new 41 kDa allergen of codfish

BACKGROUND

A 41-kDa IgE-reactive protein (p41) was purified from raw cod extract. This protein is homologous to an aldehyde phosphate dehydrogenase (APDH). The present study aims to evaluate the IgE-binding and the cross-reactivity of this protein in 13 patients allergic to codfish.

METHODS

IgE binding of sera from 13 patients allergic to codfish was tested by Sepharose RIA and by Western blot.

RESULTS

Among the 13 patients, only 4 had specific IgE to APDH detected by APDH-Sepharose RIA. The two patients who had the highest level of specific IgE to human APDH also had a class 5-6 CAP-RAST IgE level to codfish, but two other patients with a class 5 had a negative APDH-Sepharose IgE-RIA. Relative content of APDH was higher in extracts of commercial nonfrozen fish, compared to pre rigor mortis, post rigor mortis and frozen commercial codfish. A high homology of codfish APDH was found with the corresponding human enzyme. A significant inhibition of APDH-Sepharose by human and, to a lesser extent, by rabbit APDH was observed. Western blot of APDH codfish extract showed two bands at 41 and 36 kDa, respectively.

CONCLUSIONS

We have characterized a new allergen from codfish, which had a high level of homology in different species. The p41 relative content of extracts from nonfrozen codfish was higher than in the other samples assessed.

Food anaphylaxis in schools: evaluation of the management plan and the efficiency of the emergency kit

BACKGROUND

Children with severe food allergies can benefit from a personalized care project (PCP) in schools. The usefulness of the PCP and the residual risk of allergic emergencies are poorly appreciated. The objective was to evaluate the efficiency of the management plan and the training in the use of the emergency kit.

METHODS

A telephone survey using a detailed questionnaire was performed in 45 families whose children had been previously referred to the department. The distribution of disorders was as follows: asthma, 37.7%; atopic dermatitis and asthma, 28.8%; atopic dermatitis, 15.5%; angioedema and urticaria, 13.3%; and anaphylactic shock, 4.2%. Food allergy had been diagnosed in the 45 children by past history, and double-blind or single-blind, placebo-controlled food challenges (DBPCFCs, or SBPCFCs) with evidence of specific IgE. Exactly 75.5% of the children had peanut allergy. Multiple food allergies characterized 46.8% of the subjects. They had benefited from a strict elimination diet and a protocol for emergency care including a ready-to-use intramuscular epinephrine injection. A PCP had been requested by the School Public Health Service.

RESULTS

Thirty-nine PCPs were implemented (86.5% of the requests). They represented 63% of the PCPs for food allergy in the eastern region of France: one per 5800 school-age children. The retrospective period of evaluation was 25 months on average. The types of meals were very diverse, and medically acceptable in 83% of cases. The place where the emergency kit was stored in the school varied. Forty reactions occurred in 33% of the children (5/6 times in the absence of a PCP), asthma in 28%, shock in 1%, and immediate skin reactions in 11%. Reactions occurred at home in 78% of the subjects, and in school in 22% of the subjects. The cause of the reactions was not specifically known in 63% of cases. Twenty-seven percent of the reactions were linked to the ingestion of food allergens. In 10% of subjects, the reaction was due to a modification of ingredients by the food industry.

CONCLUSIONS

The frequency of respiratory symptoms during oral challenge tests was confirmed by the frequency of asthmatic reactions within the follow-up period. The role of hidden allergens and of misleading labeling validates the need for PCPs in the case of peanut and tree nut allergies, past history of severe reactions, multiple food allergies, reactions to a low dose in DBPCFCs, and asthmatic reactions to foods. This study provides encouraging data on the usefulness of PCPs and confirms the need for thorough instruction and training of the school staff in dealing with allergic emergencies. Addition of a beta-agonist spray to the emergency kit is suggested.

Intralipid 10%: physicochemical characterization

OBJECTIVES

Parenteral fat emulsions contain two populations of particles: artificial chylomicrons rich in triacylglycerols (TAG), and liposomes (bilayer of phospholipids [PL] enveloping an aqueous phase). Centrifugation permits isolating the liposomes in the infranatant called mesophase. The aim of the present work was to better characterize this mesophase chemically and to view the particles it contains by electron microscopy.

METHODS

Electron microscopy (Philips 410) was performed after cryofracture on native 10% Intralipid, mesophase (centrifugation for 1 h at 27 000 g), and a liposome-enriched fraction (ring of density 1.010-1.030 g/l obtained after centrifuging mesophase in a KBr density gradient at 100 000 g for 24 h). The TAG and protein content of the mesophase was analyzed and the proteins partially characterized by immunodetection (Western-blot).

RESULTS

This electron microscope study of 10% Intralipid gives evidence for the coexistence of artificial chylomicrons (mean diameter, 260 nm) and liposomes (43 nm), the latter being smaller than expected and containing 8% w/w TAG after purification. The solubilization of TAG in PL bilayers (reported to be < or = 3.1% w/w) might have been increased in parenteral emulsions by the manufacturing process or/and the high TAG/PL ratio. Minute amounts of proteins have also been detected and partially characterized using a specific antibody raised against the human 7 kDa Anionic Polypeptide Factor (APF), known to strongly interact with PL in bile.

CONCLUSIONS

This work has shown that the size (mean diameter, 43 nm) of the liposomes present in 10% Intralipid is smaller than that usually assumed. Traces of hydrophobic proteins in the emulsion may account for certain allergic reactions sometimes observed in infused patients.

Ingredient and labeling issues associated with allergenic foods

Foods contain a wide range of food ingredients that serve numerous technical functions. Per capita consumer exposure to most of these food ingredients is rather low with a few notable exceptions such as sugar and starch. Some food ingredients including edible oils, hydrolyzed proteins, lecithin, starch, lactose, flavors and gelatin may, at least in some products, be derived from sources commonly involved in IgE-mediated food allergies. These ingredients should be avoided by consumers with allergies to the source material if the ingredient contains detectable protein residues. Other food ingredients, including starch, malt, alcohol and vinegar, may be derived in some cases from wheat, rye or barley, the grains that are implicated in the causation of celiac disease. If these ingredients contain gluten residues, then they should be avoided by celiac sufferers. A few food ingredients are capable of eliciting allergic sensitization, although these ingredients would be classified as rarely allergenic. These ingredients include carmine, cochineal extract, annatto, tragacanth gum and papain. Food manufacturers should declare the presence of allergenic food ingredients in the ingredient listings on product labels so that allergic consumers can know to avoid these potentially hazardous products.