Search

Background: Sesame is a relevant food allergen in France. Compared to other allergens there is a lack of food challenge data and more data could help sesame allergy risk management. The aim of this study is to collect more sesame challenge data and investigate the most efficient food challenge method for future studies., Method: Records of patients at University Hospital in Nancy (France) with objective symptoms to sesame challenges were collected and combined with previously published data. An estimation of the sesame allergy population threshold was calculated based on individual NOAELs and LOAELs. Clinical dosing schemes at Nancy were investigated to see if the optimal protocol for sesame is currently used., Results: Fourteen patients (10 M/4 F, 22 ± 14.85 years old) with objective symptoms were added to previously published data making a total of 35 sesame allergic patients. The most sensitive patient reacted to the first dose at challenge of 1.02 mg sesame protein. The ED05 ranges between 1.2 and 4.0 mg of sesame protein (Log-Normal, Log-Logistic, and Weibull models) and the ED10 between 4.2 and 6.2 mg. The optimal food challenge dosing scheme for sesame follows semi-log dose increases from 0.3 to 3000 mg protein., Conclusion: This article provides a valuable update to the existing clinical literature regarding sesame NOAELs and LOAELs. Establishment of a population threshold for sesame could help in increasing the credibility of precautionary labelling and decrease the costs associated with unexpected allergic reactions. Also, the use of an optimal dosing scheme would decrease time spent on diagnostic and thereafter on the economic burden of sesame allergy diagnosis., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Background: Foods containing flaxseed proteins rich inpolyunsaturatedfatty acids are new on the market., Objectives: In a population of patients attending the allergology department, we evaluated the frequency of sensitization to flaxseed, characterized allergens and looked for modifications related to industrial processing., Methods: Natural, heated and extruded flaxseeds were tested using prick-in-prick tests (PIP using the fresh seed), SDS PAGE, immunoblots, immunoblot inhibition and Fourier Transform Infrared (FTIR) spectroscopy., Results: PIP tests to natural flaxseed were positive in 5.8% of the 1317 patients. 73 of 77 PIP-positive patients were atopic. There was cross-reactivity with five seeds. peanut, soybean, rapeseed, lupine and wheat, and with rape pollen. Immunoblot inhibition by bromelain confirmed the presence of specific IgE to cross-reactive carbohydrate determinants (CCD). 0.15% of this population presented with food allergy to flaxseed and positive PIP to heated and extruded flaxseed. Two sera showed that clinically relevant allergens in industrial products had MW between 25 and 38 kDa. Sensitization to processed flaxseed characterized only the allergic subjects. FTIR spectroscopy showed major modifications in 3 and alpha structures following industrial processing., Conclusion: Positive prick tests to natural flaxseed were mainly due to cross-reactions. Flaxseed allergy is rare and could be detected by PIP to heated extruded flaxseed. Increasing consumption callsfor monitoring of clinical risk.

The prevalence of food allergies increases in industrialized countries: 3% in general population, up to 6% of children. Food allergy has a genetic basis. The recent increase is thought to be due to a change in environmental factors, including changes in diet and reduced exposure to early childhood infection. Food allergies present with a wide spectrum of clinical manifestations, including anaphylaxis, urticaria, angioedema, atopic dermatitis, oral syndrome, asthma, rhinitis, gastrointestinal disorders. Diagnosis of food allergy is based on history, detailed dietary analysis, skin testing, measuring specific IgE, avoidance diet and challenge tests. The mainstay of diagnosis and management of food allergies is correct identification and avoidance of the offending antigen. Children often develop tolerance to cow's milk, egg, wheat by school age, whereas allergies to nuts, fish and seafood are generally not outgrown no matter at what age they develop.

Background: The prevalence of sesame allergy is increasing in European countries. Cases of severe allergy lack any evidence of specific immunoglobulin (Ig)Es by prick tests and CAPSystem-FEIA. The reasons for this negativity are unknown., Methods: In 32 patients displaying immediate symptoms such as anaphylactic shock, asthma, urticaria, angioedema, sesame allergy was diagnosed by double-blind placebo-controlled food challenge (DBPCFC) or convincing clinical history. However, 10 patients had negative prick tests and CapSystem-FEIA. The specificity of IgEs was further investigated by enzyme-linked immunosorbent assay (ELISA), isoelectrofocalisation (IEF)-blotting, and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) blotting using total sesame extracts and purified fraction of oil bodies. Monospecific rabbit antibodies directed to two oleosin isoforms (15 and 17 kDa) were used., Results: By ELISA, white sesame seed extract allowed the detection of higher levels of IgE than brown sesame extract. In all sera, numerous bands binding IgEs were detected by IEF or SDS-PAGE. In reducing conditions, two bands (15-17 kDa), could be separated from 2S albumin. Oleosins, present in oil bodies fractions, were recognized by IgEs from all sera., Conclusion: Oleosins are major allergens of sesame seeds and may be relevant to severe anaphylaxis. Falsely negative prick tests could be due to the lack of oleosins in presently available extracts, or to the fact that epitopes might be buried in the inner molecule. Detection tests currently used to identify sesame allergens based on sesame vicillins or other storage proteins could be insufficient for the detection of sesame seed contamination. Oleosins have been named Ses i 4 (17 kDa) and Ses i 5 (15 kDa), in accordance with the IUIS Nomenclature Committee.

Exercise-induced anaphylaxis (EIA) is defined as the onset of allergic symptoms during, or immediately after, exercise, the clinical signs being various degrees of urticaria, angioedema, respiratory and gastrointestinal signs and even anaphylactic shock. Food-dependent exercise-induced anaphylaxis (FDEIA) introduces food in the syndrome and is revealed by a chronological sequence in which food intake, followed by exercise, induces symptoms after a varying period. When the food intake and the exercise are independent of each other, there are no symptoms. FDEIA is not very frequent. Identifying the culprit food allergen depends on the patient's eating habits. Crustaceans and wheat flour are the two commonest but others foods can be implicated. The patho-physiology of FDEIA has not been clearly established but it appears to result from degranulation of mast cells. As with food allergy, FDEIA diagnosis is based on interview, skin and biological tests and challenge. For the clinical signs of allergy, antihistamines, corticosteroids and epinephrine may be administered. Prophylaxis aims to prevent a recurrence; the patient should be given an emergency kit to deal with any recurrent episode. After the food allergen has been identified, it should be avoided for at least 4 to 5 hours before any exercise.

Prick-tests to foods are usually carried out as the first step in the diagnosis of food allergy. Severe anaphylaxis accounts for 4.9 % of allergies in children and occurs more frequently in adults, raising the possibility of systemic reactions to prick-tests in highly sensitized people. Several studies published in the literature have used commercial extracts. As for airborne allergens, concentrations causing a skin reaction of 15 mm do not present a risk of systemic reactions. Prick-tests to native foods--prick-in-prick tests--have been less extensively studied. The CICBAA1 data, from 1,138 food allergic patients of all ages, cover 34,905 prick-in-prick tests to foods. The wheal of these prick-tests has been regulary registered. The risk of systemic reactions can be evaluated at 0.008 %. There were no severe reactions and anti-histamine and corticosteroid therapy were sufficient. These results are similar to those of the large study in 2000 carried out by Devenney in neonates (0.005%). A review of the literature reveals only a few severe reactions in adults. The authors draw attention to the necessary precautions: temporary contra-indication for skin prick-tests in children and adults with grade 3 or 4 asthma, with particular attention to such foods as all kinds of nuts, fish, etc.

A total of 4,737 people consulting allergologists were routinely tested for peanut sensitization. The study involved 84 allergologists in the Allergo-Vigilance Network over a period of 30-60 consecutive days. Investigation procedures were identical. Results classified subjects into four groups according to the clinical history and prick-tests to common inhalants: group 1: subjects suspected of having a food allergy; group 2: subjects with ongoing atopic disease; group 3: subjects with an underlying predisposition to atopy, as showed by one or more positive results to prick-tests with airborne allergens; group 4: non atopic subjects. The sensitization rates were 22.7%, 8.7%, 4%, and 0.4% respectively. Assuming that 25% of the French population is allergic the rate of sensitization to peanut in the general population should be between 1% and 2.5%. Considering a ratio of 3.3 between sensitization and clinical allergy as plausible, the prevalence of peanut allergy could be 0.3% to 0.75% of the French population. This figure is lower than that for the UK, the US and Canada (0.8% to 1.5%). The correlation between the data in this study and those from previous epidemiological studies validates the methodology used in this type of enquiry. One of the aims of the Allergo-Vigilance Network set up in 2001 is to collect data from a large number of people. We present here the results of a study carried out in 2002 by 84 allergologists in the Allergo-Vigilance Network. The primary aim was to assess the prevalence of peanut sensitization in the French population seeking treatment for various allergic disorders. The second objective was to determine whether there was any difference in risk of peanut sensitization in people with ongoing atopic disease, in those with an underlying predisposition to atopy (shown by positive prick-tests) and finally in non atopic people.

Atopic dermatitis (AD) is one of the first manifestations of the atopic march. The natural history of food allergies (FA) is closely related to AD. Sensitivity to food is demonstrated with cutaneous tests (prick-tests and atopy patch-tests) or the presence of IgE specific to food. A true allergy to a foodstuff is revealed by oral provocation tests (OPT) or by improvement during an avoidance diet. Ingestion of the food allergen during OPT can provoke an onset of eczema, an immediate reaction (urticaria, oedema) or involve other target organs (digestive disorders, rhinitis, asthma or anaphylactic shock). Seven allergens are responsible for around 90 p. 100 of FA: milk, eggs, wheat, peanuts, nuts, soy and fish. The fundamental knowledge acquired demonstrates the implication of food allergens in the physiopathogenesis of AD. The assessment of the efficacy of avoidance diets is difficult to demonstrate in standardised double-blind studies. Their efficacy is demonstrated compared with the natural history of AD. A diagnostic algorythm of FA during AD is proposed. An avoidance diet can be prescribed on 3 levels: primary, secondary and tertiary prevention. Diagnostic dietetics are aimed at initiating a hypoallergenic diet over a short period of 15 to 21 days when AD is severe and does not permit an allergy assessment. This diet is followed by an allergy assessment and OPT to determine the foodstuff responsible. Therapeutic dietetics consists in initiating an avoidance diet based on the results of the allergy assessment: positive predictive value of specific IgE, positivity of oral provocation tests or the re-introduction of the foodstuff for one week. Preventive dietetics is aimed at preventing the onset of AD: a consensus has been established by the American and European Academies of Paediatrics. In conclusion, present knowledge demonstrates that FA is a triggering factor for AD and that the avoidance diets based on allergy assessments are an essential tool in the treatment of AD. Understanding the triggering mechanisms of oral tolerance will permit the development of strategies for the prevention and cure of food allergies.

Purpose of Review: The purpose of this review is to bring the reader up to date on the importance of assessing a food's lowest observed adverse-effect level (LOAEL) with two aims. Firstly, to help industry choose tests with a level of sensitivity capable of detecting food allergens hidden in industrial products. Secondly, to specify protective measures for highly allergic individuals in order to prevent recurrent severe anaphylaxis. The review also seeks to highlight the present issues and unsolved questions., Recent Findings: Thanks to standardized oral-provocation tests (double-blind placebo-controlled food challenges), LOAELs have been identified for many IgE-dependent food allergies. Most studies concern the pediatric population. Data is available for milk, egg, peanut, wheat flour, and sesame. The LOAELs are commonly in the range of 1-2 mg of natural foods, representing a few hundred micrograms of protein. These minimal reactive doses characterize about 1% of people allergic to milk, egg, or peanut. The level at which no observed adverse effect is seen might be a few tens of micrograms of protein for peanut. At the present time, allergy to oil seems to be restricted to unrefined cold-pressed oils., Summary: Concerning IgE-dependent food allergies, the threshold dose inducing symptoms is now known to vary a great deal according to the individual. A reactive dose of less than 65 mg characterizes 16 and 18% of patients allergic to egg or peanut. Less than 30 mg of milk proteins characterizes 5% of those allergic to milk. For milk, egg, and peanut, 1% of patients have a very low threshold, about 1 mg. Such data emphasize the necessity of using detection tests with a sensitivity better than 10 parts per million. The modifications of allergenicity undergone by protein ingredients that are now commonly introduced into industrially made products are not yet sufficiently known. A better knowledge of the reactive doses of these proteins is needed.

Background: The prevalence of food allergies increases, relating to diet modifications. The consumption of new foods--exotic foods or foods originally used for animal feed, new proteins, neo allergens due to the use of new technologies and soon, Genetically Modified Foods--are in the spotlight., Objective: It is essential to develop a system of food allergy vigilance encompassing the full range of foods being consumed. Understanding this imperative leads logically to the suggestion of developing an allergy vigilance network taking advantage of the ongoing experience of allergists "on the ground"., Methods: The French Allergy Vigilance Network is subscribed to by 302 allergologists (267 of whom are French). The aims of the Network are to record cases of severe anaphylaxis, to establish an epidemiological data bank from prospective multicenter studies, and to monitor the allergic risk from novel foods., Results: In 2002, 107 cases of severe anaphylaxis were recorded: anaphylactic shock--59.8% (one fatal), systemic reaction--18.7%, laryngeal angio-edema--15.9%, acute severe asthma--5.6% (one fatal). The main allergens identified were peanuts, nuts, shellfish, lupine flour and wheat flour. Action has been taken as a result: information by industry on inadequate labeling, withdrawal of wrongly labeled batches, and university hospital centers have been encouraged to establish the allergenic safety of their catering services., Conclusion: Setting up such a network in other countries would lead to a significant advance in knowledge of the peculiarities of allergies relating to a wide variety of eating habits.

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.

Background: Mustard allergy accounts for 1.1% of food allergies in children. However, double-blind placebo-controlled food challenge trials (DB PCFCs) have not yet been proposed., Objective: To carry out DB PCFCs to determine the real frequency of mustard allergy in patients sensitized to mustard., Methods: A prospective study was conducted in 30 subjects aged 3-20 years presenting positive prick tests to ground mustard seeds (Brassica nigra), mustard flour (B. juncea), metabisulfite-free strong mustard seasoning (B. juncea) and a commercialized allergenic extract (B. nigra). Twenty-seven subjects were screened for mustard-specific immunoglobulin E (IgE). PCFCs were carried out either DB or single blind (SB) with up to 1340 mg of metabisulfite-free seasoning., Results: The mean diameter of the wheal induced by prick tests with the allergenic extract was lower (n.s.) than that induced by the native mustard products: 5.8 mm (1.5-15) vs 6.9 mm (0.5-18) for B. nigra ground seeds, 7.8 mm (1-20) for B. juncea flour and 9.7 mm (3-20) for the strong mustard seasoning. The diameter of the wheal induced by the allergenic extract was significantly different from that induced by the mustard seasoning (P < 0.005). The mean of mustard specific-IgE values was 8.7 KU/l (0.35-72.4). Seven of 30 food challenges were considered positive. Mean prick test results in the positive and negative PCFC subgroups were 5.5 mm vs 5.9 mm for the commercialized extract, 10.9 mm vs 5.8 mm for B. nigra ground seeds (P < 0.01), 9.9 mm vs 7.1 mm for B. juncea flour (n.s. P > 0.25) and 11.5 mm vs 9.1 mm for the metabisulfite-free mustard seasoning (n.s. P > 0.1). Mean specific IgE values determined by CAP system radioallergosorbent test (Phadebas Pharmacia) were higher but not significantly so (P > 0.25) in the subgroup with mustard allergy (12.3 K/l vs 7.6 KU/l)., Conclusions: About 23.3% of the sensitized subjects were allergic to a routine dose of mustard. Positive prick tests and the presence of specific IgE were not predictive. SB PCFC or DB PCFC is required before recommending avoidance diets.

Food allergy could affect up to 8% of children. Four cases of food anaphylaxis in hospitalized children are reported, pointing to the need of food allergenic safety procedures in hospital settings. The implementation of the operating procedure in hospital food production units (HFPU) of Nancy University Hospital is described. The dietetics Department developed on hypoallergenic diet and specific avoidance diets. Dieticians within HFPU managed the choice of starting materials, the circuit organization in order to avoid any risk of contamination during preparation and cooking of food, product traceability, and trained the staff of HFPU. Within the care units physicians, dieticians, nurses, hospital workers are involved in meal management. A diet monitoring sheet is integrated into the patient's nursing file and enables the dietician to validate the diet in the computer, the nurses to display the patient's diet on the schedule on the wall in their office. The hospital workers finally use a tray form indicating the patient's identity, his/her diet and the menu of the day. Such a procedure absolutely secures the whole circuit and specifies the responsibilities of each person, whilst ensuring effective cooperation between all partners. Since 1999, the implementation of this multi-step strategy has prevented from any further reaction in a department specialized for food allergies in children and in adults. As setting up food allergenic safety in hospitals in not addressed adequately in the European directives, it's judicious to draw attention of hospital catering managers and hospital canteen staff to this necessity.

Numerous biological tests point to the diagnosis of food sensitization: detection of specific IgEs by Rast techniques, multi-detection assays, immunoblotting, screening of basophil activation (BAT or FAST), assays for leukotriene LTC4 release (CAST), measurement of plasma histamine, serum tryptase, serum ECP, urinary EDN, completed by mannitol-lactulose test evaluating intestinal permeability, assay of fecal IgEs, Rast for specific IgG4. Primary screening for anti-food IgEs by multi-detection assays seeks justification from insufficient clinical data and false positive tests are common in patients sensitized to pollens or latex, on account of in vitro cross reactivities (CR). Multiple CR explain positive Rast to vegetal food allergens in such patients. Biological tests should not be performed as the first line of diagnosis. In vivo sensitisation is assessed by positive prick-tests, demonstrating the bivalence of allergens, as well as the affinity of specific IgEs, two conditions necessary to bridge membrane bound specific IgEs, leading to the release of mediators. Prick-tests are closer to clinical symptoms than biological tests. However, the diagnosis of food allergy is based on standardised oral challenges. Exceptions are high levels of specific IgEs to egg (> 6 kUl/l), peanut (> 15 kUl/l), fish (> 20 kUl/l) and milk (> 32 kUl/l), reaching a 95% predictive positive value. Rast inhibition tests are useful to identify masked allergens in foods. Research developments will have impact on the development of new diagnostic tools: allergen mixes reinforcing a food extract by associated recombinant major allergens, multiple combination of recombinant allergens (chips) or tests with synthetic epitopes aimed a the prediction of recovery. Laboratory tests take place in the decision free for the diagnosis for the food allergy and the follow-up of the levels specific IgEs is a tool to assess outcome and contributes to predict recovery or persistent allergy. Up to now the significance of positive laboratory tests showing the implication of IgEs is at the crossroads of the allergist's and biologist's expertise.

Introduction: The management in schools of children with life-threatening or chronic diseases has led to the development of Individual Reception Projects (IRP) since 1993, notified in the state education ministry's circular letter. The aim of this study was to assess the status of such IRPs in France and the French Overseas Territories in the management of food allergy risks., Method: The regional departments of educational promotion were contacted and the survey was run between May and June, 2002. The items of the questionnaire were: the number of IRPs for anaphylactic emergencies, details on the allergies themselves, an overview of the eventual existence of dialogue structures among school physicians, heads of schools, allergists, treatment prescribers and emergency protocols., Results: The total survey revealed 7482 IRP for anaphylactic reactions to food (14% of the total IRPs). The frequency of IRPs varied greatly depending on the regions. The Paris area represented 36.3% of the total. The Lorraine area: 5.6%, the Haute-Garonne: 5%, and the Bouches-du-Rhône: 3.3%. The IRPs represented 0.002 (Ardèche) to 0.33% (Alpes-de-Haute-Provence) of the school attending population. The mean level was of 0.065%; 71.6% of the IRPs concerned the 1st grade (1 IRP for 1091 children). In decreasing frequency, the allergens concerned were: peanuts, eggs, dried nuts, fish, dried peas and milk. Dialogue structures were established in 38 regions., Discussion: The IRPs have increased 4-fold since the circular letter in 1999. The enhanced prevalence of numerous (new) allergies to dried nuts and leguminous plants has been emphasized, and peanut allergies have been confirmed. The complexity of managing the IRPs and need for information and training of state education and municipal staff requires the further development of dialogue structures, which are still clearly insufficient.

Background: Allergy to sesame seeds is often associated with particularly severe reactions, with a high risk of anaphylaxis. The increase in reports of allergic reactions to sesame is probably due to the growing use of sesame seeds or sesame oil in food., Objective: To determine the molecular weights of the proteins in three variety of sesame seeds and to study the isoelectric points and the allergenicity of white sesame proteins., Methods: Extracts of white, brown and black sesame seeds were prepared. The white sesame extract, mostly used in bakery, was run on SDS-PAGE and two dimensional electrophoresis. Six sera from patients sensitized or symptomatic to sesame seed were used for Western blotting., Results: The protein patterns of the white, brown and black sesame extracts showed major quantitative differences. The white extract had the higher protein concentration and contained 15 proteins of 12-79 kDa, some of them having several acidic isoelectric points. The lowest isoelectric point was 4.9 and the highest was 6.4, giving 35 isoforms. Ten of the 15 proteins (12-57.5 kDa) were recognized by specific IgE. The 12-13 kDa and 22-33 kDa proteins could correspond to the main allergens., Conclusion: White sesame seeds contain at least 10 allergenic proteins with acidic isoelectric points. In accordance with previous results, two of them seem to contain the major allergens.

Background: Numerous products based on soybean are available and various food technologies are applied for their production. The allergenicity of natural soybean may be modified by these treatments., Objectives: To compare the allergenicity of native soybean proteins with those of soy milk and texturized protein products. To show additional allergens., Methods: Three commercial products and two infant formulas were studied: Soybean flour, soy milk, texturized soy proteins, two infant formulas; the first containing total proteins and the second containing a soy protein hydrolysate. Sera from 9 patients allergic to soy protein were tested by immunoblotting (IB). IB inhibition was achieved by incubating sera with protein extract from soybean flour., Results: The SDS-PAGE profile of soybean flour protein and soy milk showed a difference in the proportions of the various protein fractions, with a higher concentration of 37-kD protein in flour and 33-kD protein in milk. Infant formula 1 contained proteins with a molecular weight below 28 kD. The texturized extract contained high proportions of 31- to 34- and 38-kD proteins. Immunoblotting revealed a lack of allergenicity in infant formula. Sera recognizing the 38- and 50-kD proteins in texturized soy protein also recognized the 37- and 49-kD proteins in soybean flour and in soy milk, suggesting a protein glycation by texturization processes. The 30- to 34-kD band in texturized proteins was devoid of any allergenicity. This study seems to indicate that the 30-kD allergen (Gly m Bd 30) disappears during the production of texturized soy protein., Conclusion: All technologies applied to soybean-based products induce striking variation in the protein profile and allergenicity. Texturized protein could lack the major allergen Gly m Bd 30. Further studies or texturization might generate modified technologies in order to create hypoallergenic texturized proteins., (Copyright 2002 S. Karger AG, Basel)

The Allergo-vigilance Network including 200 French allergologists and 28 European ones, has three objectives: to index the cases of lethal or prelethal anaphylaxis, to evaluate the prevalence of food allergies, clinical pictures and allergens, and to implement the post-marketing surveillance of the allergic risk of novel foods. The first survey dealing with life-threatening food allergies leads to an estimation of 15,000 to 30,000 reactions per year in France. The AVN could be a helpful tool for public health organizations.

Background: Spices originate in various botanical families: Apiaceae, Lamiaceae, Lauraceae, Leguminosae, Liliaceae, Myristicaceae, Myrtaceae, Piperaceae, Solanaceae, Zingiberaceae...., Methodology: Prick-tests to native spices have been carried out in patients suspected of food allergies to spices. The CICBAA data bank includes 589 cases of food allergies, a part of which has benefited from investigations for spices. Data about the rate of sensitization and food allergy are available., Results: Frequent sensitization to Apiaceae is observed: coriander, caraway, fennel, celery: 32% of prick-tests in children, 23% of prick-tests in adults. Sensitization to Liliaceae: garlic, onion, chive, is observed in 4.6% of prick-tests in children, 7.7% of prick-tests in adults. Rare cases of sensitization to paprika and saffron are recorded. Prick-tests to nutmeg, ginger and clove are currently negative. 10 food allergies related to the mugwort-celery-spices syndrome are reported: coriander: 1, caraway: 2, fennel: 3, garlic: 3, onion: 1. Food allergy to spices is unfrequent: 2% of the totality of food allergies. However, only adults are allergic to spices and allergy to spices accounts for 6.4% of food allergies in adults. Tiny amount of proteins are usually ingested. Patients at risk of spice allergy are young adults sensitized to mugwort and birch allergens, sharing cross-sensitization with various food vegetal allergens. The clinical suspicion raises from frequent post-prandial systemic reactions. Other allergens of vegetal origin have to be cleared. Diagnosis can be established by DBPCFC using powdered spices in capsules.

Food allergy to cow's milk proteins (APLV) is frequently found in young infants. Treatment is by starting an elimination diet. Different substitution products have been proposed: soya milk, partial hydrolysate of the proteins of lactoserum, powdered casein hydrolysate, hydrolysed soya and pork collagen. Allergic reactions to soya milk, hydrolysates of lactoserum proteins, powdered casein hydrolysates and hydrolysates of soya have been described. The study that we present evaluates the effect on the natural development of these allergies of a formula based on amino-acids (Neocate) in 26 patients who presented a syndrome of multiple allergies one of which was a food allergy to milk. Twenty-five of them had a severe atopic dermatitis, isolated (14 cases), or associated with gastro-intestinal troubles (6) break in the growth curve (5), anaphylactic reactions (2), one asthma (1). One child had a chronic diarrhoea associated with a weight plateau. Evaluation 2 or 3 months later showed a significant improvement of the atopic dermatitis. Return of the stature-weight growth was noted in 4 children from 5, the check in one was reported as due to a initially unrecognised allergy to gluten. The recovery of the APLV was shown by double-blind oral provocation test in 20/23 children between 11 and 37 months (22 +/- 9). Duration of administration of Neonate was between 6 to 19 months (12 + 5) months. This study confirmed the beneficial effect of the amino-acid formula on weight gain, gastro-intestinal troubles and development of atopic dermatitis. The level of recovery of APLV of 86% at the age of 2 years is better than that reported in the syndrome of multiple food allergies of 22%. The influence of this diet on the development of other food allergies remains to be evaluated.

Food allergy to wheat flour is a pathology that is found less frequently than coeliac disease or respiratory allergy to flour; it seems however to be a constant argument. Our study used a panel of 28 patients diagnosed with food allergy to wheat flour. Our objective was to characterise the reactivity of type IgE and IgG antibodies of these patients with regard to the different classes of proteins of wheat flour so as to establish an antigenic profile of the allergens of wheat in the framework of food allergy to flour. Our results show the implication of different classes of wheat proteins and notably the major reserve proteins (gliadins and glutens) in food allergy.

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.

Food allergy is an important public health problem. The prevalence of IgE-mediated food allergy is estimated at 3.24% of French population. Clinical pictures are varied: atopic dermatitis, urticaria and oedema, asthma, rhinitis, anaphylactic shock. Their comparative frequencies change with age. The risk of fatal anaphylactic reactions (acute asthma, anaphylactic shock, laryngeal oedema) is underlined. The role of risk factors on expression of food allergy is important: exercise, concomitant intake of alcohol, aspirin NAIDS, beta-blockers or converting enzyme inhibitors. The modifications of food habits and of food allergenicity by agro-alimentary technology, the consumption of novel foods and masked allergens explain the present aspects of food allergy. The role of intestinal flora and early diversification of food influence the acquisition of tolerance. The diagnosis of food allergy depends of the expert appraisement of the allergologist. Oral challenge tests distinguish sensitisation from true food allergy. Treatment is based on targeted eviction diet. Contact with food allergen must be avoided by other way: skin (cosmetic), respiratory tract and drug intake. The control of risk factors is essential.

Background: Food allergy (FA) is an important health problem for which epidemiologic studies are needed., Objective: We performed an epidemiologic survey in France to determine the prevalence, clinical pictures, allergens, and risk factors of FA., Methods: This study was conducted on 33,110 persons who answered a questionnaire addressed to a representative sample of the French population on a scale of 1:1000 (44,000 subjects aged

Background: Histamine is thought to be the main cause of adverse reactions to wines., Objective: The purpose of this study was to test the hypothesis that the level of histamine in wine affects the tolerance to wine in 16 subjects with wine intolerance., Methods: We performed a study to examine the effects of wine histamine content in 16 adults with wine intolerance. Each subject underwent 2 double-blind provocation tests with wine: 1 with a wine poor in histamine (0.4 mg/L), and 1 with a wine rich in histamine (13.8 mg/L). Blood was collected for histamine and methylhistamine RIAs at 0, 10, 30, and 45 minutes after ingestion of the wine. Methylhistamine and methylimidazolacetic acid (gas chromatography and mass spectrometry) were measured in urine 5 hours before and 5 hours after ingestion., Results: No significant differences in the occurrence of adverse reactions were noted after ingestion of either of the wines (McNemar test). At 10 minutes, a significant increase was observed in plasma histamine with histamine-poor wine. No significant changes (Wilcoxon test) were observed in the methylhistamine and methylimidazolacetic acid levels after ingestion of either histamine-poor or histamine-rich wine., Conclusion: This study demonstrates that there is no correlation between the histamine content of wine and wine intolerance. The increase of plasma histamine levels at 10 minutes with histamine-poor wine suggested the role of a histamine-releasing substance. The role of acetaldehyde is discussed.

Background: Peanut-containing food products may induce severe clinical reactions in sensitized subjects, and high levels of antipeanut IgE have been reported in the literature. Immunotherapy, proposed for the prevention of severe accidents, is often ill-tolerated and only partly efficient. This could be due to the spontaneous development of polyisotypic antipeanut antibodies., Objective: To appreciate the presence and reactivity of other isotypes other than IgE of peanut-specific antibodies in serum samples from peanut-sensitized subjects., Methods: Serum samples were obtained from 20 non-sensitized subjects and 23 sensitized patients divided in three groups according to their response to peanut oral challenge (no response or response to high or low doses, respectively). Peanut-specific IgG, IgG subclasses, IgA and IgM were assayed using an ELISA, and their reactivity against peanut proteins tested using Western Blot., Results: A large dispersion of antipeanut antibody levels was observed in the three groups of patients, high levels of IgG, IgG1, IgG4 and IgA usually correlating with highly positive radioallergosorbent test (RAST). Such high levels were observed at onset in four patients who underwent peanut immunotherapy who had side effects and poor efficiency. Western blotting demonstrated that the polyisotypic response observed was directed to several peanut antigens, including the major allergens, Ara h1 and Ara h2., Conclusion: Peanut-sensitized patients who spontaneously develop specific IgE, display polyisotypic-specific antibody responses, whatever their response to oral challenge. This might explain the poor efficiency of peanut rush immunotherapy attempts.

Background: Although allergy to sunflower seed and oil is a relatively rare occurrence, several cases of sunflower seed allergy have been observed, and we have already described one case of anaphylaxis after eating sunflower oil and margarine., Objective: The aim of our study was to determine and characterize the allergens from sunflower oil at the different steps of the refining process: crude pressed oil (step A), acidification and neutralization (step B), pregumming by centrifugation (step C), washing (step D), bleaching (step E), gumming by filtration (step F), and deodorization (step G)., Methods: A sample of oil from each step of the process (steps A to G) was heat extracted with PBS. The protein concentration of each extract was evaluated by using the micro-Bradford assay. Samples were run on SDS-PAGE. The immunoblot was performed with the serum of a patient sensitized to sunflower seed and oil., Results: The extracts obtained after each step reveal a decrease in total protein concentration from 13.6 microg/mL to 0. 22 microg/mL. The result of SDS-PAGE shows 5 bands, from 67 kd to 145 kd, with the most abundant being the 67-kd protein. The amount of this protein decreases after each step of the process. It is, however, still present in trace amounts in the refined oil. The 67-kd protein, which is mainly present in the crude oil and slightly in the refined oil, has been shown to be allergenic., Conclusion: Because of the presence of allergenic proteins, refined sunflower oil may pose a threat to people highly sensitized to sunflower seeds.

Unlabelled: Lupine flour (lupinus albus), recently authorized in France in human food, cross-reacts with peanuts. We report a case of acute asthma in a patient with allergy to peanuts., Exegesis: This patient has a severe allergy to peanuts, presenting as acute asthma. Skin prick-tests to raw and cooked lupine flour were positive. The level of specific-IgE (Allerbio, France) to lupine flour were high. Oral challenge test induced acute asthma at a dose of 965 mg of lupine flour. This quantity may be included in 100 g of bread., Conclusion: This case report points out the fact that lupine flour is a high-risk allergen in patients presenting allergy to peanuts. It is necessary to evaluate the allergenic risk of new foods before their introduction into human daily food intake and to establish a network of allergy vigilance.

Multiple food intolerance in infants and young children is increasingly diagnosed. More than 40% of infants less than 1 y.o. could be affected. The syndrome is characterized by the seriousness of atopic dermatitis (SCORAD > 50), by enterocolitis or failure to thrive or various associations of symptoms that may change over time. The evolution is long-lasting. Common food allergens are milk, egg, soy, wheat, but other ones can be implicated. The diagnosis is established by standardized oral challenges. Multiple etiopathogenic factors are involved: atopy, gastro-enteritis induced intestinal hyperpermeability, precocity of food diversification, breast-feeding continued after the onset of symptoms. Amino-acid based formulas have changed the evolution.

Background: Peanut allergy is common, but cross-allergy between legumes is rare. Proteins from Lupinus albus are increasingly eaten in the form of seeds or additives to wheat flour. The risk of cross-allergenicity is still insufficiently known., Objective: We sought to study the risk of cross-allergy to lupine in patients allergic to peanut and to study lupine allergenicity., Methods: Twenty-four patients allergic to peanuts were studied by means of skin prick tests with native lupine flour from Lupinus albus. Double-blind oral challenge tests were performed with lupine flour and peanut in 8 of these patients. Specific IgEs were assayed for peanut, lupine flour, and pollen in 6 sera. RAST inhibition tests for lupine pollen by peanut were performed on 4 of these sera. Peanut and lupine flour immunoblots were carried out for 6 sera, and crossed immunoblot inhibitions for peanut by lupine flour and lupine flour by peanut were carried out for 2 sera., Results: The skin prick test responses with lupine flour were positive in 11 (44%) subjects. The challenge test responses were positive in 7 of 8 subjects at the same doses as with peanut. The major lupine flour allergen (molecular mass, 43 kd) is present in peanuts. The RAST inhibition and immunoblot tests indicated cross-reactivity of peanut with the lupine flour and pollen., Conclusions: The risk of crossed peanut-lupine allergy is high, contrary to the risk with other legumes. The inclusion of 10% lupine flour in wheat flour without mandatory labeling makes lupine a hidden allergen, presenting a major risk of cross-reaction in subjects already allergic to peanut products. A high sensitizing potential can also be postulated for this legume.

The aims of this work were to investigate, in children and adolescents, the clinical aspects of food hypersensitivity and the distribution of allergens, in a prospective and descriptive study. Five hundred and forty-four pediatric cases from a series of 703 patients with food allergies, confirmed by food challenge, were studied. Their clinical characteristics and the distribution according to allergen were investigated. There was a family history of atopic disease in 70.5% of patients. Atopic dermatitis was the main symptom (275/544; 50.5% of patients), followed by urticaria and angio-edema (165/544; 30%). There was asthma in 8.6% of patients (47 children) and anaphylaxis in 4.5% (27 patients). The rarest signs were rhinitis (n=2; 0.3%), oral allergy syndrome (n=8; 1.4%), and gastrointestinal signs (n=11; 2%). Five allergens accounted for 78% of food hypersensitivity. These allergens were: eggs (36%), peanuts (24%), cow's milk (8%), mustard (6%), and cod (4%). Peanut was the most common allergen for children over the age of 3 yr. In this selected population, sensitivity of individuals to more than three foods was unusual (5%). Atopic dermatitis was the main symptom of food allergy in children. The symptoms changed over time, with respiratory disorders, oral allergy syndrome and ocular problems occuring later. Anaphylaxis also occured mostly in older children. Five allergens were responsible for more than three-quarters of food allergies in children. However, the number of allergens implicated was higher for the group of children over the age of 6 yr than for younger children.

Wheat flour is a basic foodstuff. Food allergy has been especially described in children, in the form of atopic dermatitis. Food allergy in adults is rare and especially described in the form of anaphylactic shock sometimes induced by effort. Four observations of adult food allergy are presented. The IgE dependent mechanism is documented. The positive oral provocation tests needed doses of 17 to 30 grams. One crossed sensitivity between rye and barley was seen. The major allergen was probably gluten, particularly gliadines. Sensitization was probably due to prolonged inhalation of wheat flour. The authors stress the possibility of food allergy to wheat flour by other mechanisms, the difficulty of diagnosis, needed for a diet without cereal and gluten that is now non reimbursable.

Food hypersensitivity is increasing, with clinical indications and allergens multiplying and evolving. We report our experience with clinical indications and distribution of allergens in children with food hypersensitivity. Data were established in a prospective study at medical centres in Nancy and Toulouse (France). We studied 378 children with food hypersensitivity indicated by food challenge, which account for 74.2% of food hypersensitivity. Clinical features were: atopic dermatitis (46.5%), urticaria (17.9%), oedema (14.2%), asthma (8.4%), anaphylaxis (5.2%), gastro-intestinal symptoms (2.1%), oral syndrome (1.8%) and rhino-conjunctivitis (0.5%). Five allergens accounted for 82% of confirmed food hypersensitivity: egg (51.8%), peanut (34.3%), milk (11.6%), mustard (8.9%) and codfish (7.1%). Allergens according to the symptoms showed that peanut allergies were more serious than other food allergy. Allergens according to age showed that peanut allergy is the first food allergy occurring after the age of three. There exists a modification in children's allergen distribution. Peanut allergy is increasing seriously, and diagnosis with food challenge is a necessity.

Background: IgE-dependent basophil activation induced by an allergen elicit the release of LTC4 and the expression of the CD63 membrane marker., Objective: The aim of this study was to check if flow cytometric analysis of basophil activation could be applied to food allergy diagnosis and if this method paralleled LTC4 release., Methods: Patients were selected by the clinical history, skin tests, and provocation tests. Basophil activation induced by food extracts was studied in 24 control subjects and in 27 patients having a food allergy by LTC4 release test (LRT) and by flow cytometric anti-IgE+, CD63 + cell counting (BAT = basophil activation test). In case of negative anti-IgE response a passive blood donor basophil passive sensitization step was added to LRT and BAT. Leucocyte histamine release test was performed in 11 patients., Results: Basophil activation test was positive in 18/31 cases and LRT in 22/34 cases for food-allergic patients and, respectively, in 1/33 and 1/35 cases for the controls. A correlation was observed between specific IgE, BAT, and LRT. Basophil activation test and LRT performed after passive sensitization had an excellent sensitivity only for specific IgE levels ranging between 3.5 and 35 KU/L., Conclusion: The present study shows that allergen-induced LTC4 release and anti-IgE, antiCD63 bicolor flow cytometric analysis of basophil activation may be used for food allergy diagnosis. Both tests have a good sensitivity and specificity. Basophil activation test and LRT are more efficient than histamine release test in case of high spontaneous histamine release, frequently observed in case of food allergy.

Background: The increase in frequency of peanut allergy and fatal cases have been reported., Objectives: The objective of this study is to document the severity of food allergy to peanuts by evaluating the reactive dose of peanuts and to search for the role of peanut oil., Methods: This study is carried out on the basis of 142 observations collected according to the same diagnostic methodology in two allergy centres in France. Skin-prick-tests were performed with peanut powder, peanut oil and peanut oil proteinic extract. Labial provocation tests were performed on 121 patients. The reactive dose of peanuts and the role of peanut oil were determined by standardized oral provocation tests in 50 and 62 patients respectively. The data are computerized and the data bank includes 509 food allergic patients., Results: Allergy to peanuts represents 28% of food allergies and occurs under 1 year of age in 46% of cases, under 15 years of age in 93%. The clinical features were atopic dermatitis (40%), angioedema (37%), asthma (14%), anaphylactic shock (6%) and digestive symptoms (1.4%). The specific IgE were class 3 or higher in 80% of cases. The total reactive dose was less than 100 mg in 25% of cases, from 100 mg to 1 g in 62.5%. All patients reacted to a dose of less than 7.1 g. The threshold of peanut reactivity was lower than the threshold of egg reactivity. An allergy to peanut oil was demonstrated in 14 patients., Conclusion: The severity of peanut allergy and the early onset of the occurrence of this allergy is documented. The role of residual allergenic proteins in peanut oil is established by positive skin-prick tests to proteic extracts from peanut oil and by double-blind placebo-controlled challenges to peanut oil. The increased consumption of allergens in the form of peanut oil and fats can contribute to the occurrence or persistence of symptoms and may be suspected to increase the risk of sensitisation.

Allergic reactions to peanut oil are very much debated, even if the responsibility of peanut oil has been evoked in several cases of adverse reactions, including death related to severe asthma. The aim of the present study was to investigate the presence of allergenic proteins in peanut oil. Proteins were extracted from commercial refined peanut oil, with a relative content in the order of 0.1-0.2 microg per g of oil, and molecular sizes ranging from 14 up to 76kDa in SDS-PAGE. Eight protein bands were systematically observed in crude, neutralized and refined oils, with a molecular mass ranging from approximately 14 to 76 kDa, including one at 18 kDa which was identified by Western blot performed with serum from two allergic patients. The protein extract gave positive IgE-RIA with patient sera, positive in vitro leucocyte histamine release tests and positive skin-prick tests in allergic patients. The allergenic protein was purified by HPLC and [125I] iodide-labelled. It had an isoelectric point at 4.5 in isoelectrofocusing. In conclusion, we have demonstrated the presence of allergenic proteins in crude and refined peanut oil. These proteins are the same size as two allergens previously described in peanut protein extracts.

Several food proteins are used as food additives or may be contained in foods as contaminants. These masked allergens are at high risk of inducing severe clinical reactions: acute asthma, laryngeal angioedema, anaphylactic shock or even death. The present regulation requires labelling only if the level of food ingredients is superior to 25% of the final product. Several immunologic methods can detect low levels of proteins, equal or inferior to 2%. However a level of 1% or less may be noxious, suggesting a need for a specific line of food products which could be guaranteed free of ... and which might be recommended to patients with food allergy.

Background: Hypersensitivity to sesame seeds is becoming increasingly frequent, probably owing to the larger use of this compound in international food., Objectives: This study investigated serum responses of 12 sesame sensitized patients (seven with food allergy, five with food sensitization), to a sesame protein extract, and attempted at identifying sesame major antigens., Methods: Sesame protein extracts were prepared from black, white and brown sesame seeds. Electrophoretic analysis showed similar protein patterns in the three extracts, and proper preservation of the proteins integrity. The brown sesame extract was used to set-up an ELISA assay and measure serum levels of antisesame IgG, IgA, IgM and IgE in 12 samples from sesame-sensitized individuals and six controls. It also allowed to perform western blot analyses in order to investigate the molecular weight of sesame proteins recognized by IgG, IgA and IgE., Results: Nineteen protein bands were observed upon polyacrylamide gel electrophoresis of the sesame protein extracts. Using this whole extract in ELISA, significant antisesame IgG, IgA and IgE-responses were observed in the serum of sensitized individuals, different from the lower signals obtained with control samples. Western blot analysis demonstrated highly polymorphic IgG and IgA responses and a more restricted IgE response pattern, suggesting that two proteins, respectively, 14 kDa and 25 kDa are mostly involved in sesame IgE-dependent hypersensitivity, the 25 kDa band presenting several characteristics of a major allergen., Conclusions: This study reports novel information on the possible involvement of a 25 kDa sesame protein in IgE-dependent hypersensitivity to sesame seeds.