Anaphylactic shock induced by gadoterate meglumine (DOTAREM)

The use of contrast agent for magnetic resonance imaging improves the effectiveness of this diagnostic examination. Complexes of godolinium, which appear to be well tolerated, are used for this purpose. A few cases of anaphylactic shock have been attributed to these agents. We report a case of anaphylactic shock due to gadoterate meglumine (DOTAREM). While undergoing a magnetic resonance imaging examination, a 33-year-old nonatopic female patient became severely hypotensive, lost consciousness, and had generalized erythema immediately after the intravenous injection of this product. She recovered rapidly after she was given injection of epinephrine and her blood volume was restored with intravenous fluids. That DOTAREM had caused this immediate hypersensitivity reaction was proven by the positivity of prick-test and intradermal test at 10-3 (0.37 mg/ml) and in vitro leukocyte histamine release test. The results of these tests indicated that it was the gadoteric acid rather than the meglumine component of DOTAREM that was responsible: positivity of IDR at 10 mg/ml. Skin tests and leukocyte histamine release test to gadopentetate dimeglumine (MAGNEVIST) were negative. In addition of the exceptional character, this observation provides evidence for an immediate hypersensitivity without cross reactivity with gadopentetate dimeglumine.

[Allergies in orthodontics]

In contrast with work-related allergies amongst dentists and dental prosthetictists, allergies in patients followed in orthodontics concerning the materials placed in the mouth were rare. It may be a question of limited manifestations in the buccal cavity (urticaria, angio-oedema, stomatitis, chellitis), or more generalised manifestations (Quincke's oedema, eczema). The number of materials used in orthodontics is limited. The observations concerning metals are less numerous whilst those that concern the resins are exceptional. On the other hand, the risk linked to latex is very real. Allergy investigations require skin tests, sometimes to mucous tests and in some cases to provocation tests. Use of eviction measures may be not only the only diagnostic method but also a therapeutic method. Systematic search for an allergy to metal or a resin posed by the prosthetic material does not seem to be necessary. In the case of suspicion of latex, confirmed ultimately by an allergic history, this imposes start of the eviction measures.

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.

Food allergy to wheat: identification of immunogloglin E and immunoglobulin G-binding proteins with sequential extracts and purified proteins from wheat flour

BACKGROUND

Cereal-associated allergy is particularly considered a serious problem, because cereals are essential in our daily diet. Wheat proteins are classified into albumins, globulins and prolamins (insoluble gliadins and glutenins).

OBJECTIVES

Our objectives were to study the involvement in food allergy to wheat of these different protein types by using purified fractions and to identify those binding IgE and IgG antibodies.

METHODS

Sera were obtained from 28 patients with food allergy to wheat. Albumins/globulins, gliadins and glutenins were obtained by sequential extraction based on differential solubility; alpha-, beta-, gamma- and omega-gliadins and low molecular weight (LMW) and high molecular weight (HMW) glutenin subunits were purified by chromatography. IgE binding to these extracts and fractions were analysed by radioallergosorbent test (RAST), and immunoblotting; IgG binding was detected by enzyme-linked immunosorbent assay (ELISA).

RESULTS

In RAST, 60% of sera were shown to have specific IgE antibodies against alpha-, beta-gliadins and LMW glutenin subunits, 55% to gamma-gliadins, 48% to omega-gliadins and 26% to HMW glutenins. Immunoblotting analysis confirmed results obtained in RAST concerning LMW and HMW glutenin subunits and showed that 67% of patients have IgE antibodies to the albumin/globulin fraction.

CONCLUSION

Results obtained in the different tests showed common features and in agreement with other studies indicated the presence of numerous allergens in food allergy to wheat; alpha-, beta-, gamma- and omega-gliadins, LMW glutenin subunits and some water/salt-soluble proteins appeared as major IgE binding allergens, whereas HMW glutenins were only minor allergens. The same type of antigenic profile against gliadins and glutenins was observed with IgG antibodies. Important sequence or structural homologies between the various gliadins and LMW glutenin subunits could certainly explain similarity of IgE binding to these proteins.

Food safety of allergic patients in hospitals: implementation of a quality strategy to ensure correct management

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.

Laboratory tests for diagnosis of food allergy: advantages, disadvantages and future perspectives

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.

[The individual reception project (IRP) for anaphylactic emergencies. The situation in France and French overseas territories in 2002]

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.

Optimal management of atopic dermatitis in infancy

The necessity to optimise the management of atopic dermatitis of infants needs knowledge of three components: increase of prevalence, extreme frequency of food allergy and increase in the frequency of the syndrome of multiple allergies, that frequently develops into asthmatic disease. Management of DA in infancy (first year of life) is based on the global strategy of understanding the physiological Th2 polarisation at birth, that does not allow a re-equilibration of the Th1-Th2 balance that progresses in the first six months of life (in normal infants) making in this period a window of opportunity for sensitizations. Prevention in high-risk children (familial history of atopy) covers the non-exposure to in door pollutants (tobacco and volatile organic compounds), breast-feeding or a hypoallergenic formula for a hydrolysate of pork and soya proteins or better an extensive hydrolysate of casein. Four situations require moving to an amino acid substitute: failure to thrive, severe atopic dermatitis, a syndrome of multiple food allergies, allergy to hydrolysates. Reintroduction of foods should be considered with the least delay so as to induce digestive tolerance. It should take into account the clinical development, the intensity of the sensitisation and eventually depend on a realistic test of introduction. Management of DA searches for recovery of generalized eczema, failure to immediate improvement of quality of life prevention of immediate complications (local sepsis) acceleration of return to food tolerance. Prevention of ulterior development of asthma by immediately introducing measures to diminish respiratory exposure to allergens and tobacco is hoped for.

[Food allergy diagnosis]

The diagnosis of food allergies (FA) relies upon the sequential use of different means and tools, according to a decision tree. Ten clinical characteristics point to a potential FA. A diary for food consumption during a week surveys all labellings, in order to detect masked food allergens. The second step is based on skin prick tests to natural foods, and epicutaneous tests to a few proteins (casein, gluten...). Biological tests using multi detection tests of specific IgEs to numerous allergens are not advised owing to the frequency of clinically not relevant in vitro cross-reactivity. Single determination of specific IgEs, have a 95% predictive positive value of high levels in cases of allergy to milk, egg, fish and peanut, and can spare oral challenges. The primary use of biological tests is not currently advised but may be of interest in litigious cases. Standardized oral challenges are the golden standard. Eviction regimens are an alternative used for cow's milk allergy in infancy, or for suspected digestive allergies in adults.

Anaphylaxis to muscle relaxants: rational for skin tests

IgE-dependent allergy to muscle relaxants (MR) has an estimated prevalence of 1 out of 6500 General Anesthesias (GA). 62% of anaphylaxis during surgery are due to MR anaphylaxis. All the molecules are divalent, carrying two NH4+ epitopes (quaternary ammonium ions), either structurally or after rapid in vivo protonization (vecuronium). The excellent overall performance of skin test makes them the golden standard for the diagnosis of anaphylactoid reactions. Techniques include intradermal tests and prick-tests. The current localizations are the forearm and the back. Positivity criteria are 3 mm for prick-tests. For IDTs, the criterium is the doubling of the size of the injection papula, when 0.02 to 0.04 ml is injected: 8 mm. The recommended concentrations are not falsely negative. Commercial concentrations can be tested by prick tests, except for mivacurium and atracurium tested of 1:10 dilution. A scale of concentrations is advised for IDT starting with 1:10,000, up to a normally non reactive concentration that is: 100 micrograms/ml (succinylcholine), 200 micrograms/ml (gallamine), 10 micrograms/ml (atracurium), 2 micrograms/ml (mivacurium), 200 micrograms/ml (pancuronium), 400 micrograms/ml (vecuronium), 1,000 micrograms/ml (rocuronium), 200 micrograms/ml (cis atracurium). The specificity and sensitivity of the skin tests to MRs are greater than 95%. The reproducibility over years is 88%. The overall concordance of PT and IDR is 97%. Both types of tests can be used for the diagnosis. IDT have to be carried out for the search of the cross sensitization. 84% of patients do have cross sensitization to MRs but only 16% react to all MRs. The further use of MRs selected by negative IDTs has been proved to be safe.

Allergenicity of some isoforms of white sesame proteins

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.

[Current features of food allergies: the need of allergy surveillance]

The prevalence of food allergy in European populations has been evaluated at between 1.8 and 4.4%. In the French population it is 3.24%. This frequency, as well as the gravity of some manifestations, has already led to preventive and curative measures being taken in school settings. This increase is related to multiple environmental factors: changes in intestinal microflora, early diversification of foods in children, interference of drugs favoring clinical severity in adults. Allergenicity can be modified by food industry techniques. The appearance of novel foods (exotic proteins or those derived from animal feed, and soon GMOs), the growing use of food proteins as ingredients, constitute new risks. The absence of validated experimental methods for evaluating the allergic risk of food proteins makes it necessary to implement a policy of allergy vigilance for novel foods. Studies concerning the allergic risk for lupin flour, a new ingredient used in baked goods, are given as an example. They indicate the frequency of sensitization and cross peanut-lupin flour allergy, the low reactive threshold, indicating the risk of the level of incorporation presently allowed. They make possible current screening for this allergy in the population. Allergy vigilance is a recent concept that aims to set up surveillance of food allergy risks in a manner analogous to that of pharmacovigilance for drugs. A project for creating such a structure is being discussed. Although the central structure remains at the initiative of the Agence Française de Sécurité Sanitaire de l'Alimentation (French Agency for Food Safety) and the Institut de Veille Sanitaire (Institute of Health) the authors specify what a peripheral network of allergists should be, analyze the desired content of the bi-directional flow of information, and propose envisaging an intermediate regulatory organization, specialized in the diagnosis and treatment of food allergies. The ongoing idea is that environmental pressures on the genetics of atopic disease lead to a continuum of IgE-dependent responses towards all the potential allergens in the entire population. Consequently, the creation of such a structure is advised in the name of the Precautionary Principle.

First survey from the "Allergy Vigilance Network": life-threatening food allergies in France

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.

[Allergenicity of lupin flour]

Lupin flour is used in human food for its high quality nutritional and functional qualities. The frequency of crossed allergy between lupin flour and peanuts, both members of the family of Leguminosae, is strong, since 68% of patients who are allergic to peanut have shown positive reactions to lupin flour when tested by TPO-DA. Cases of isolated allergy to lupin flour without pre-existence of peanut allergy as well as workplace asthma by inhalation are also rarely seen. The specific allergens of lupin and those that participate in crosses with peanut have been studied by SDS-PAGE and immunoblot. The diversity of allergens contained in different lupin flour has also been studied. Further, the detection of lupin flour in a "pizza" flour which induced a strong allergic reaction exposed its eventual implication as a masked allergen.

[Occupational asthma due to hard metals hypersensitivity]

The authors report the case of a worker in the hard metal industry presenting with asthma due to cobalt and nickel. The diagnosis was supported by the history, positive skin tests and lymphocyte activation as well as elevated levels of the metals in the urine and BAL. Challenge led to a delayed asthmatic reaction occurring 3.5 to 24 hours after exposure. The BAL contained high levels of tungsten and cobalt, the level of the latter doubling 48 hours after exposure. After the provocation test a nasal and broncho-alveolar eosinophilia was observed. The possibility of a delayed hypersensitivity reaction to metals is discussed by the authors.