Assessment of the tolerance to lupine-enriched pasta in peanut-allergic children

Background Reports of allergy to lupine derivatives (as de novo sensitization or cross-reactivity in subjects allergic to peanut) are increasing as their use in food products increases.
Objectives The aim of this study was to assess: (1) lupine tolerance in a group of children allergic to peanut, using lupine enriched-pasta instead of raw flour as has been done in previous clinical studies; (2) whether technological treatments of lupine modify its cross-reactivity or co-sensitization with peanut; (3) the role of lupine seed proteins in sensitization, and (4) to identify the eliciting doses (EDs) by using double-blind, placebo-controlled food challenges (DBPCFC).
Methods Twelve patients with a history of clinical allergic reactions to peanut were evaluated by skin prick tests (SPTs), the ImmunoCAP^® test, immunoblotting, and DBPCFC. The 12 selected subjects were included in a trial where lupine-enriched pasta and placebo pasta were administered in a DBPCFC protocol.
Results Positive clinical reactions were observed in two children, the EDs being 0.2 and 6.4 g of pasta, corresponding to 50 mg and 1.6 g of lupine proteins, respectively. β-conglutin was the protein most involved in SPT positivity.
Conclusion Lupine-enriched pasta can be tolerated by most subjects suffering from peanut allergy, but a sizeable minority (2/12 of them in this case) can develop potentially dangerous clinical reactions. Information about possible reactions to lupine derivatives by those allergic to peanuts must be included in the labelling of lupine-enriched products to protect consumers at risk.     

Sensitization to lupine flour: is it clinically relevant?

Background Lupinus angustifolius (blue lupine) is used for human and animal consumption. Currently, the lupine content in bread varies from 0% to 10% and from 0.5% to 3% in pastry. Although lupine flour is present in many products, anaphylaxis on lupine flour is rarely seen. Objective The aim of our study was to determine the clinical relevance of sensitization to lupine flour. Methods From October 2004 until October 2005, we performed skin prick tests (SPT) with lupine flour, peanut and soy extracts in consecutive patients attending our allergy clinic with a suspected food allergy. In patients sensitized to lupine flour, double‐blind placebo‐controlled food challenges (DBPCFC) were performed and specific IgE was measured. Results We tested 372 patients. SPTs with peanut, soy and lupine flour were positive in 135, 58 and 22 patients, respectively. Nine patients with sensitization to lupine flour underwent DBPCFC, which was negative in eight cases. In contrast, one patient experienced significant symptoms. Four of these nine patients suspected lupine by history. Two other patients with a positive history to lupine declined from challenges. In these patients, a 3‐day dietary record showed that they could consume lupine without symptoms. Specific IgE in the serum was positive for L. angustifolius, peanut and soy in all nine patients. Conclusion These results demonstrate that clinical lupine allergy is very uncommon, even in the presence of sensitization to lupine flour. The estimated prevalence of lupine allergy, among patients with a suspected food allergy, referred to a tertiary allergy centre in the Netherlands is 0.27–0.81%. In most, although not all cases, sensitization is not clinically relevant and is most likely caused by cross‐sensitization to peanut. In selected cases, eliciting doses are low, making significant reactions possible. Cite this as: N. W. de Jong, M. S. van Maaren, B. J. Vlieg‐Boersta, A. E. J. Dubois, H. de Groot and R. Gerth van Wijk, Clinical & Experimental Allergy, 2010 (40) 1571–1577.     

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

BACKGROUND: Current labeling practices for allergenic foods like peanut can be inadequate. For future regulatory and industry guidelines, information on no-observed-adverse-effect levels (NOAELs) and eliciting doses (EDs) for allergenic foods is necessary. OBJECTIVE: To determine NOAEL and ED in a representative group of peanut-sensitized children, relate these data to history and sensitization, and evaluate the outcome of dietary management. METHODS: From an overall eligible group of 96 peanut-sensitized children, a representative group of 27 was evaluated by questionnaires, skin prick test, determination of specific IgE, and double-blind placebo-controlled food challenge (DBPCFC) with peanut according to the international consensus protocol, with 9 doses ranging from 10 microg to 3 g peanut flour. Dietary management was evaluated over a 12-month period. RESULTS: Twenty-two children (81%) had a positive DBPCFC. The NOAEL in this group was 1 mg peanut flour, corresponding to 2 mg whole peanut. The ED for subjective symptoms (10 mg to 3 g) was significantly lower than for objective symptoms (100 mg to 3 g; P = .002). Severe reactions occurred only at high doses. EDs were not correlated to previous reactions by history, skin prick test, or specific IgE levels. All patients with a positive DBPCFC were advised to follow a strict diet. During the follow-up period, 10 patients had a less strict diet likely containing traces of peanut. In 3 cases, a mild reaction occurred with food products labeled "may contain peanut." CONCLUSION: The NOAEL in a representative group of children with peanut allergy was 2 mg. Dietary compliance in half of this group was inadequate.     

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

BACKGROUND: Reports of lupine allergy are increasing as its use in food products increases. Lupine allergy might be the consequence of cross-reactivity after sensitization to peanut or other legumes or de novo sensitization. Lupine allergens have not been completely characterized. OBJECTIVES: We sought to identify allergens associated with lupine allergy, evaluate potential cross-reactivity with peanut, and determine eliciting doses (EDs) for lupine allergy by using double-blind, placebo-controlled food challenges. METHODS: Six patients with a history of allergic reactions to lupine flour were evaluated by using skin prick tests, CAP tests, and double-blind, placebo-controlled food challenges. Three of these patients were also allergic to peanut. Lupine allergens were characterized by means of IgE immunoblotting and peptide sequencing. RESULTS: In all 6 patients the ED for lupine flour was 3 mg or less for subjective symptoms and 300 mg or more for objective symptoms. The low ED and moderate-to-severe historical symptoms indicate significant allergenicity of lupine flour. Two patients allergic to lupine but not to peanut displayed IgE binding predominantly to approximately 66-kd proteins and weak binding to 14- and 24-kd proteins, whereas patients with peanut allergy and lupine allergy showed weak binding to lupine proteins of about 14 to 21 or 66 kd. Inhibition of binding was primarily species specific. CONCLUSION: Lupine allergy can occur either separately or together with peanut allergy, as demonstrated by 3 patients who are cosensitized to peanut and lupine. CLINICAL IMPLICATIONS: Lupine flour is allergenic and potentially cross-reactive with peanut allergen, thus posing some risk if used as a replacement for soy flour.     

Cow's milk allergy in adults is rare but severe: both casein and whey proteins are involved

Background Studies on cow's milk allergy (CMA) in adults are scarce. Little is known about the clinical symptoms, eliciting doses (ED), and allergens involved.
Objective The aim of this study was to analyse the clinical symptoms, ED and allergen recognition in adult CMA patients, compared with cow's milk (CM)-sensitized, but tolerant controls.
Methods Adult CMA patients were evaluated by standardized questionnaires ( n =30), skin prick tests (SPTs) and specific IgE for CM allergens ( n =18), and a double-blind placebo-controlled food challenge (DBPCFC, n =10). A control group ( n =25) of CM-sensitized, but tolerant adults was included.
Results The majority of CMA patients (20/30, 67%) reported severe symptoms. In all patients participating in DBPCFC, CMA was confirmed. ED for subjective symptoms (0.3–300 mg CM protein) were significantly lower than that for objective symptoms (300–9000 mg CM protein). The severity of CMA by history and ED was not correlated with SPT or IgE. Patients had higher SPT reactivity than controls for CM, α-lactalbumin and β-lactoglobulin ( P =0.002, P =0.014 and P =0.004) but not for casein. Specific IgE to CM tended to be higher ( P =0.068) and IgE to casein was higher in patients than that in controls ( P =0.016). No difference was observed for IgE to α-lactalbumin and β-lactoglobulin.
Conclusion Adult CMA is severe in nature. ED are low, starting from 0.3 mg CM protein. Patients with CMA recognize the same major allergens (casein and whey proteins) as controls, but display a stronger SPT and IgE reactivity.     

Basophil activation tests for the diagnosis of food allergy in children

Background Positive skin prick tests (SPT) for food allergens and specific IgE (sIgE) in serum indicate sensitization but do not enable distinction between sensitized but tolerant and clinically allergic patients.
Objective Herein, we evaluate the clinical relevance of basophil activation tests (BATs) for peanut or egg allergy diagnosis.
Methods Thirty-two peanut-allergic, 14 peanut-sensitized (sIgE⁺ and/or SPT⁺ to peanuts) but tolerant children and 29 controls with no history of an adverse reaction to peanuts were included. Similarly, 31 egg-allergic, 14 egg-sensitized children (sIgE⁺ and/or SPT⁺ to egg white) and 22 controls were studied. Flow cytometric analysis of CD63 expression or CD203c upregulation on basophils and the production of leukotrienes (LT) were performed in response to an in vitro crude peanut extract or ovalbumin (OVA) challenge.
Results After in vitro peanut challenge, the basophils from peanut-allergic children showed significantly higher levels of activation than those from controls ( P <0.001). After OVA challenge, a similar distinction ( P <0.001) was observed between egg-allergics and controls. Interestingly, the majority of egg- or peanut-sensitized children failed to activate basophils, respectively, in response to OVA and peanut challenge. The sensitivity of the CD63, CD203c and LT assay was 86.7%, 89.5% and 76.0% with a specificity of 94.1%, 97.1% and 94.6% for peanut allergy diagnosis. The corresponding performances of BATs applied to egg allergy diagnosis were 88.9%, 62.5% and 77.8% for the sensitivity and 100%, 96.4% and 96.4% for the specificity.
Conclusion Neither conventional tests nor BATs are sensitive and specific enough to predict food allergy accurately. However, BATs may helpfully complete conventional tests, especially SPT, allowing improved discrimination between allergic and non-allergic individuals.     

The EuroPrevall surveys on the prevalence of food allergies in children and adults: background and study methodology

Background:  The epidemiological surveys in children and adults of the EU-funded multidisciplinary Integrated Project EuroPrevall, launched in June 2005, were designed to estimate the currently unknown prevalence of food allergy and exposure to known or suspected risk factors for food allergy across Europe. We describe the protocol for the epidemiological surveys in children and adults. This protocol provides specific instructions on the sampling strategy, the use of questionnaires, and collection of blood samples for immunological analyses.
Methods:  The surveys were performed as multi-centre, cross-sectional studies in general populations. Case–control studies were nested within these surveys. The studies in children aged 7–10 years and adults aged 20–54 years were undertaken in eight centres representing different social and climatic regions in Europe.
Results:  After a community-based survey collecting basic information on adverse reactions to foods, all those stating they had experienced such reactions, as well as of a random sample of those stating 'no reactions' to foods, completed a detailed questionnaire on potential risks and exposures. Also a blood sample was taken to allow serological analysis to establish patterns of food and aeroallergen sensitization. We also included a questionnaire to schools on their preparedness for dealing with food allergy amongst pupils. Subjects reporting adverse reactions to foods and sensitized to the same food(s) were called in for a full clinical evaluation that included a double blind placebo controlled food challenge (DBPCFC), following a protocol which is described in detail elsewhere.
Conclusions:  The outcome of these studies will help to improve our understanding of several important aspects of food allergies in the European Community, providing for more well-informed policies and effective measures of disease prevention, diagnosis and management.     

Food allergy – accurately identifying clinical reactivity

Up to 25% of adults believe that they or their children are afflicted with a food allergy. However, the actual prevalence of food allergy is much lower: approximately 6–8% of children suffer from food allergy during their first 3 years of life, and many children then develop clinical tolerance. Food allergy encompasses a whole spectrum of disorders, with symptoms that may be cutaneous, gastrointestinal or respiratory in nature. Food disorders also differ according to the extent that they are immunoglobulin E (IgE)-mediated. Skin-prick testing is often used to identify food sensitization, although double-blind, placebo-controlled food challenge (DBPCFC) tests remain the gold standard for diagnosis. Recent evidence suggests that quantitative IgE measurements can predict the outcome of DBPCFC tests and can replace about half of all oral food challenges. When an extensive medical history is obtained in combination with IgE quantification, even fewer patients may require formal food challenges. It has also become possible to map the IgE-binding regions of many major food allergens. This may help to identify children with persistent food allergy, as opposed to those who may develop clinical tolerance. In future, microarray technology may enable physicians to screen patients for a large number of food proteins and epitopes, using just a few drops of blood.     

Asthma induced by inhalation of flour in adults with food allergy to wheat

Background Wheat is one of the major food allergens and it is also an inhalant allergen in workers exposed to flour dusts. Food allergy to wheat in adulthood seems to be rare and has never been reported to be associated with asthma induced by flour inhalation.
Objective The study aimed at detecting adults with food allergy to wheat and screening them for the presence of specific bronchial reactivity to inhaled wheat proteins.
Methods Adults with a history of adverse reactions to ingestion of wheat underwent skin prick test with commercial wheat extract and were assessed for the presence of specific wheat IgE in the sera. Food sensitivity to wheat was confirmed by double-blind, placebo-controlled food challenge (DBPCFC). Specific bronchial reactivity was investigated through a specific bronchial challenge with wheat proteins.
Results In nine patients with evidence of specific IgE response to wheat, a diagnosis of food allergy was made by DBPCFC. Only two subjects had asthma as disease induced by ingestion of wheat. Seven subjects reported a history of respiratory symptoms when exposed to flour dusts. A significant reduction of forced expiratory volume in 1 s (FEV₁) was detected in these seven patients when a specific bronchial challenge with flour proteins was performed. Only three out of seven subjects with asthma induced by flour could be considered occupationally exposed to flour dusts.
Conclusion For the first time, it has been shown that specific bronchial reactivity to wheat proteins can be detected in patients with different disorders associated with food allergy to wheat. The presence of asthma induced by inhaled flour is not strictly related to occupational exposure and it may also occur in subjects not displaying asthma among symptoms induced by wheat ingestion.     

Dietary treatment of childhood atopic eczema/dermatitis syndrome (AEDS)

Objective:  This review summarizes the research and clinical evidence in favour of dietary intervention aimed at eliminating allergenic foods in the management of atopic eczema/dermatitis syndrome (AEDS).
Data sources:  The data source was PubMed, using a search algorithm selecting for clinical studies of AEDS, diet therapy and food allergy in all children to October 2003. Also included is a commentary based on the authors' clinical experience in the allergy unit of a university hospital in Italy.
Results:  Fourteen prospective studies matched the entry criteria. Diverse trial designs, diagnostic criteria, types of dietary intervention and length of observation periods precluded meta-analytic methods. Allergenic food exclusion claimed efficacy in 13 of the 14 studies and was most useful in infants, in patients with elevated immunoglobulin E levels and/or multiple food sensitization and in patients with a diagnosis of food allergy.
Conclusion:  Dietary intervention in the form of an elimination diet is efficacious in children with AEDS when a specific diagnosis of food allergy has been made. Diagnostic evaluation of food allergy should be performed in all children with eczema, particularly in younger children and those with severe forms of the disease.     

Prevalence and cumulative incidence of food hypersensitivity in the first 3 years of life

Background:  Prevalence and incidence of food hypersensitivity (FHS) and its trends in early childhood are unclear.
Methods:  A birth cohort born on the Isle of Wight (UK) between 2001 and 2002 was followed-up prospectively. Children were clinically examined and skin prick tested at set times and invited for food challenges when indicated.
Results:  Nine hundred and sixty-nine children were recruited and 92.9%, 88.5% and 91.9% of them respectively were assessed at 1, 2 and 3 years of age. Prevalence of sensitization to foods was 2.2%, 3.8% and 4.5% respectively at these ages. Cumulatively, 5.3% [95% confidence interval (CI): 3.9–7.1] children were sensitized to a food. Using open food challenge and a good clinical history, the cumulative incidence of FHS was 6.0% (58/969, 95% CI: 4.6–7.7). Based on double-blinded, placebo-controlled, food challenge (DBPCFC) and a good clinical history, the cumulative incidence was 5.0% (48/969, 95% CI: 3.7–6.5). There is no evidence to suggest that the incidence of FHS has increased, comparing these results with previous studies. Overall, 33.7% of parents reported a food-related problem and of these, 16.1% were diagnosed with FHS by open challenge and history and 12.9% by DBPCFC and history. Main foods implicated were milk, egg and peanut.
Conclusions:  By the age of 3 years, 5–6% of children suffer from FHS based on food challenges and a good clinical history. There were large discrepancies between reported and diagnosed FHS. Comparing our data with a study performed in the USA more than 20 years ago, there were no significant differences in the cumulative incidence of FHS.     

Dual sensitization to rat and mouse urinary allergens reflects cross-reactive molecules rather than atopy

Background:  Sensitization to rats and mice can develop in laboratory animal workers exposed to only one species. Reasons for this dual sensitization are unclear but may reflect a genetic predisposition to developing allergy (atopy) or alternatively cross-reactivity between rat and mouse urinary allergens. We examined cross-reactivity between rat and mouse urine and the effect atopy has on dual sensitization in laboratory animal workers.
Methods:  In a cross-sectional study the frequency of sensitization to rat and/or mouse was analysed in 498 employees exposed to both rat and mouse at work and 220 to rat only. RAST inhibitions, western blots and blot inhibitions were carried out on a subset of five individuals to assess cross-reactivity.
Results:  Fourteen per cent of workers were sensitized to rats and 9% to mouse. Over half (62%) of rat sensitized individuals were also mouse sensitized and the majority (91%) of mouse sensitized individuals were also rat sensitized. IgE cross-reactivity was demonstrated between rat and mouse urine using RAST inhibitions. Rates of atopy did not differ between rat only sensitized individuals compared with those sensitized to both species. Sensitization to cats and rabbits was more common amongst those with dual sensitization.
Conclusions:  Dual sensitization to rat and mouse reflects IgE cross-reactivity rather than atopy. Individuals with dual sensitization are more likely to be sensitized to other animal allergens. These findings will have implications for individuals working with only one rodent species who develop sensitization and symptoms to be aware of the potential for allergy to other species.     

Patterns of quantitative food-specific IgE-antibodies and reported food hypersensitivity in 4-year-old children

Background:  Diagnosis of food hypersensitivity (FHS) is difficult and interpretation of food allergy tests is complicated.
Objective:  To investigate the probability of reported FHS in relation to levels of food-specific IgE-antibodies (AB) in a population-based setting of 4-year-old children ( n  = 2336).
Methods:  Information on FHS was obtained from a questionnaire and specific IgE-AB to milk, egg, fish, peanut, soy and wheat were analysed.
Results:  Thirty-one per cent of the children with reported FHS ( n =  284) were sensitized (≥0.35 kU_A/l) to at least one of the tested foods compared with 11% of children without FHS ( n =  2052). Furthermore, the probability of reported symptoms to milk, egg and fish increased with increasing levels of food-specific IgE-AB to the same food allergens. A similar trend was seen for peanut and wheat, but not for soy. Increasing levels of specific IgE-AB to milk or egg were also associated with an increasing risk of reported symptoms caused by other foods.
Conclusions:  Quantitative measurements of IgE-AB to milk, egg and fish are useful to evaluate IgE-associated FHS in preschool children also in a population based sample. Such measurements appear to be of limited value for soy bean and wheat, in particular as a screening method.     

Relevance of serum IgE estimation in allergic bronchial asthma with special reference to food allergy

Studies suggest the importance of serum total and specific IgE in clinical evaluation of allergic manifestations. Such studies are lacking in Indian subcontinent, though a large population suffer from bronchial asthma. Here relevance of serum total and specific IgE was investigated in asthmatics with food sensitization. A total of 216 consecutive patients (mean age 31.9 years, S.D. 11.8) were screened by various diagnostic testing. Out of 216 patients, 172 were with elevated serum total IgE (201 to > 800 IU/ml). Rice elicited marked positive skin prick test reactions (SPT) in 24 (11%) asthma patients followed by black gram 22 (10%), lentil 21 (9.7%) and citrus fruits 20 (9.2%). Serum total IgE and specific IgE showed significant correlation, p = 0.005 and p = 0.001, respectively, with positive skin tests. Blinded food challenges (DBPCFC) with rice and or black gram confirmed food sensitization in 28-37% of cases. In summary, serum total IgE of 265 IU/ml or more with marked positive SPT (4 mm or more) can serve as marker for atopy and food sensitization. Specific IgE, three times of normal controls correlates well with positive DBPCFC and offers evidence for the cases of food allergy.     

Lupin allergy in peanut-allergic children and teenagers

Background:  Lupin has now been introduced into food production in the UK. There is a concern that, on account of cross-reactivity, peanut-allergic children are at high risk for lupin allergy.
Aims:  To investigate the prevalence of lupin sensitization and allergy in children with peanut allergy compared with atopic controls.
Methods:  Children (<18 years) were recruited. Peanut-allergic subjects either had a convincing history of peanut allergy with diagnostic peanut skin prick test (SPT) or specific-immunoglobulin E (IgE) results or a positive food challenge. Control subjects were atopic but not peanut-allergic. All subjects had SPT to peanut and lupin. Sensitized subjects were offered a randomized, double-blind, placebo-controlled lupin challenge. Lupin allergy was defined as objective immediate hypersensitivity reaction at food challenge.
Results:  Forty-seven peanut-allergic children and 46 atopic controls were recruited. Sixteen peanut-allergic children were sensitized to lupin [34%, 95% confidence interval (CI): 21–49%]. Nine were challenged to lupin. Two reacted (itchy mouth and urticaria; itchy mouth and 20% drop in peak expiratory flow rate) giving a minimum prevalence of lupin allergy in peanut-allergic children of 4.0% (95% CI: 1–15%). Atopic controls were significantly ( P  = 0.001) less likely to be sensitized to lupin (4%, 95% CI: 1–15%) and had smaller wheals and serum-specific IgE results. None of the atopic controls reacted on lupin challenge, giving a rate of allergy in the atopic controls of 0% (95% CI: 0–8%).
Conclusions:  A small but significant number of children with peanut allergy are allergic to lupin. Sensitization to lupin is much rarer in nonpeanut-allergic atopic subjects.     

Incremental prognostic factors associated with cow's milk allergy outcomes in infant and child referrals: the Milan Cow's Milk Allergy Cohort study

BACKGROUND: The prognosis for many children with cow's milk allergy (CMA) is remission within 3 years, and the clinical parameters that predict duration of disease have not been measured incrementally. OBJECTIVE: To prospectively determine prognostic predictors of tolerance in a random cohort of referrals using CMA workup outcomes as covariates and tolerance as the status variable in a duration model of CMA. METHODS: The 2001-2006 Milan Cow's Milk Allergy Cohort (MiCMAC) enrolled children referrals using double-blind, placebo-controlled food challenges (DBPCFCs) as study end points (confirmation of CMA; onset of tolerance). The Cox regression model was used to analyze all clinical factors that contributed to tolerance. Covariates analyzed were skin, gastrointestinal, and respiratory symptoms; history and demographics at presentation; age at diagnosis and DBPCFC outcomes; sensitization (skin and serum) by cow's milk protein fractions; sensitization to other food and inhalant allergens; total IgE levels; specific IgE concentrations for cow's milk protein fractions, other ingestants, and aeroallergens; and threshold doses at DBPCFC. Sensitization and DBPCFC were performed at 6-month intervals. RESULTS: A total of 112 infants were enrolled (mean [SD] age, 13.85 [9.84] months), and 59 achieved tolerance (mean [SD] age when tolerance was achieved, 27.58 [11.81] months). On univariate analysis, asthma and/or rhinitis at presentation was an independent predictor of persistence (hazard ratio [HR], 2.19; 95% confidence interval [CI], 1.26-3.82). On multivariate analysis, predictors of persistence were a fresh milk wheal diameter increment of 1 mm (HR, 1.18; 95% CI, 1.07-1.31) and a positive skin prick test result with soy (HR, 6.99; 95% CI, 1.56-31.25). CONCLUSIONS: This is the first study, to our knowledge, to identify incremental biological predictors of delayed tolerance to cow's milk in children that should be integrated into DBPCFC schedules for CMA in infants.     

Lupine-induced anaphylaxis in a child without known food allergy.

BACKGROUND: Lupine allergy is caused by ingestion of the flour of a plant called Lupinus albus, a member of the Leguminosae family. Lupine allergy has been described in adult patients previously known to have peanut allergy (cross-reactivity). OBJECTIVE: To describe the first case of an anaphylactic reaction caused by ingestion of lupine flour in a pediatric patient without a known peanut allergy. METHODS: Symptom assessment, nutritional history, and skin and blood tests. RESULTS: An otherwise healthy 8-year-old boy had nose and eye discharge followed by facial edema and difficulty breathing 30 minutes after eating an industrially prepared waffle containing eggs, sugar, and lupine flour. He had no history of food allergy and was eating a normal diet, including peanuts and other legumes. Results of skin prick tests using commercial extracts were positive to peanuts and negative to eggs, soy, and nuts; results of a prick-to-prick test using lupine flour were strongly positive (+ + + +). His total IgE level was 1,237 UI/mL. Specific IgE antibodies were positive to lupine seeds (20.8 kU/L) and peanuts (> 100 kU/L). CONCLUSIONS: To our knowledge, we describe the first case of an anaphylactic reaction after ingestion of lupine flour in a child without known allergy. In the case of peanut allergy or any anaphylactic reaction without evident cause, especially after industrially prepared food ingestion, lupine should be considered in the list of allergens tested. Lupine is increasingly used in industrially prepared food but is not regularly declared in the composition, leading to difficulties in allergen avoidance.     

Mustard allergy confirmed by double-blind placebo-controlled food challenges: clinical features and cross-reactivity with mugwort pollen and plant-derived foods

BACKGROUND: Mustard IgE-mediated allergy is supposed to be a rare cause of food allergy, and its clinical features and cross-reactivities have not been fully elucidated. METHODS: A prospective study was carried out, recruiting mustard allergic patients, and paired control subjects. A clinical questionnaire was administered, and skin-prick tests (SPT) with panels of aeroallergens and foods, serum extraction for in vitro tests and double-blind placebo-controlled food challenges (DBPCFC) were performed. RESULTS: Thirty-eight mainly adult patients, with 10.5% reporting systemic anaphylaxis, were included in the study [age (mean +/- SD): 21.9 +/- 8.6 years]. DBPCFC were performed in 24 patients, being positive in 14 cases (58.3%). Patients with positive outcome showed significantly greater mustard SPT than those with negative outcome (8.2 +/- 3.7 vs 5.3 +/- 2.4 mm, P <0.05), and the receiver-operating characteristic (ROC) curve analysis yielded a cut-off value for mustard commercial SPT of 8 mm, with a specificity of 90% (95% CI, 55.5-98.3), and a sensitivity of 50% (95% CI, 23.1-76.9). A significant association between mustard hypersensitivity and mugwort pollen sensitization was found (97.4% of patients), with partial cross-reactivity demonstrated by UniCAP System inhibition assays. All patients showed sensitization to other members of Brassicaceae family, and cross-reactivity among them was also confirmed. Moreover, significant associations with nut (97.4%), leguminous (94.7%), corn (78.9%), and Rosaceae fruit (89.5%) sensitizations were also shown. Around 40% of these food sensitizations were symptomatic, including food-dependent exercise-induced anaphylaxis in six patients. CONCLUSIONS: Mustard allergy is a not-uncommon disorder that can induce severe reactions. Significant associations with mugwort pollinosis and several plant-derived food allergies are demonstrated, suggesting a new mustard-mugwort allergy syndrome. A relationship between this syndrome and food-dependent exercise-induced anaphylaxis is also reported.     

Double-blind placebo-controlled challenges for peanut allergy the efficiency of blinding procedures and the allergenic activity of peanut availability in the recipes

Background:  A firm diagnosis of double-blind placebo-controlled food challenge (DBPCFC) would facilitate the diagnosis in patients with uncertain history of reaction. Guidelines are lacking for an upper provoking dose and how to hide high concentrations of peanuts.
Aim:  To develop and evaluate a double-blind recipe with minimum 10% of peanut. To compare the recipe with published recipes regarding blindness, taste, texture and immunoglobulin (Ig)E antibody binding to peanut.
Methods:  A recipe (I) with 10% of peanut was developed evaluated and used in DBPCFC. The challenges were followed by development of a concentrated recipe (II) (15% peanut, 25% fat). Recipe II was compared with the only published recipe (III) (11% peanut, 7% fat) regarding taste, texture and availability of peanut. Recipe IV (12% peanut, 10% fat) was developed using the same methods. The binding of IgE in the recipes was measured using an inhibition method.
Results:  During challenges, one patient reacted after 4 g, emphasizing the need for blinding recipes containing high doses of peanut. Evaluation between recipes II and III, only recipe II was regarded as blind by the taste panels. A tenfold lower availability of peanut protein in the recipe II was found at 50% of inhibition. Recipe IV had a better IgE binding that did not differ from the original peanut extract.
Conclusion:  The peanut taste and texture can be hidden in a challenge medium. The fat content was important for the availability of the allergenic protein in challenges. The availability of allergens must be taken into consideration when used for DBPCFC.     

Allergy to jackfruit: a novel example of Bet v 1-related food allergy

BACKGROUND: Jackfruit allergy has been reported just once. It is unknown whether this food allergy is caused by direct sensitization or cross-sensitization to pollen allergens. OBJECTIVE: Establish whether jackfruit allergy is linked to birchpollen allergy. METHODS: Two jackfruit allergic patients and five patients with birchpollen-related apple allergy were recruited. Sensitization to pollen and plant foods was assessed by skin prick test (SPT), radio-allergosorbent test (RAST) and immunoblot. RAST analysis was performed for Bet v 1 and Mal d 1. Cross-reactivity was evaluated by RAST and immunoblot-inhibition. Biological activity of immunoglobulin E (IgE) was measured by basophil histamine release. Allergy to jackfruit was evaluated by double-blind placebo-controlled food challenge (DBPCFC) or open challenge (OC). RESULTS: In both patients DBPCFC confirmed the reported jackfruit allergy. SPT was 41 and 27 mm2 and specific IgE to jackfruit was 5.9 and 0.8 IU/ml, respectively. Immunoblot analysis revealed IgE reactivity at Mr of approximately 17 kDa. The Bet v 1-related nature of this allergen in jackfruit was demonstrated by RAST and immunoblot inhibition. To assess whether jackfruit allergy might be common in patients with combined birchpollen-fruit allergy, five such patients underwent an OC with jackfruit. All five had OA-like symptoms. CONCLUSIONS: Jackfruit allergy can be added to the list of birchpollen-related food allergies. Increased consumption of this fruit will result in a rise in allergic reactions.