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Barbara K Ballmer-Weber

Publications and source records attributed to Barbara K Ballmer-Weber.

15 recordsLinked to original sources
PubMed2007

IgE-mediated food allergy diagnosis: Current status and new perspectives.

In June 2005, the work of the EU Integrated Project EuroPrevall was started. EuroPrevall is the largest research project on food allergy ever performed in Europe. Major aims of the project are to generate for the first time reliable data on the prevalence of food allergies across Europe and on the natural course of food allergy development in infants. Improvement of in vitro diagnosis of food allergies is another important aim of the project. The present review summarizes current knowledge about the clinical presentation of food allergy and critically reviews available diagnostic tools at the beginning of the project period. A major problem in diagnosis is a relatively poor 'clinical specificity', i. e. both positive skin tests and in vitro tests for specific IgE are frequent in sensitized subjects without food allergy symptoms. So far, no in vitro test reliably predicts clinical food allergy. EuroPrevall aims at improving the predictive value of such tests by proceeding from diagnosis based on allergen extracts to purified allergen molecules, taking into account the affinity of the IgE-allergen interaction, and evaluating the potential of biological in vitro tests such as histamine release tests or basophil activation tests including assays performed with permanently growing cell lines.

Allergens↗
PubMed2006

Tolerance to celecoxib in patients with a history of adverse reactions to nonsteroidal anti-inflammatory drugs.

BACKGROUND: Adverse reactions to nonsteroidal antiinflammatory drugs (NSAIDs) are frequently reported, particularly among asthmatic patients. To date, there is no causal treatment available apart from tolerance induction. Therefore, the search for safe alternative drugs is of pivotal importance in clinical practice. OBJECTIVE: The aim of our prospective study was to investigate the tolerance to celecoxib, a selective cyclooxygenase-2 inhibitor, in a large group of patients with positive case history of NSAID intolerance in comparison to paracetamol and nimesulide. METHODS: 106 NSAID-sensitive patients, 46 (43.4%) of whom had experienced reactions only to one NSAID (single hypersensitivity), 60 (56.6%) to several NSAIDs (multiple hypersensitivity), were included in a single-blinded drug challenge protocol with cumulative doses of 175 mg of celecoxib, 875 mg of paracetamol and 175 mg of nimesulide. Objective and subjective symptoms during challenge were documented. RESULTS: Of 261 challenges in 106 patients, 31 challenges were positive: 5 of 106 (4.7%) for celecoxib, 10 of 64 (15.6%) for paracetamol and 16 of 91 for nimesulide (17.6%). Adverse reactions to celecoxib were mainly mild in character: three patients reported subjective symptoms including generalised pruritus and thoracic oppression, whereas two patients reacted with angio-oedema. CONCLUSIONS: Our results demonstrate that celecoxib is well tolerated by the majority of patients with NSAID intolerance. However, since adverse reactions to celecoxib cannot be ruled out completely, a controlled oral challenge test is still mandatory for proper management of patients with NSAID intolerance.

Acetaminophen↗
PubMed2006

Wheat and maize thioredoxins: a novel cross-reactive cereal allergen family related to baker's asthma.

BACKGROUND: Baker's asthma is a serious problem for a significant proportion of workers in bakeries, confectionaries, and the food industry. Although several wheat allergens related to baker's asthma have been described, standardized reagents for a reliable diagnosis are not yet available. OBJECTIVE: To clone novel wheat allergens related to baker's asthma and investigate the cross-reactive potential of their maize and human homologues. METHODS: A wheat cDNA phage display library was screened with sera from bakers with occupational asthma for IgE-binding structures. Homologous sequences from maize and human thioredoxins were amplified from corresponding cDNA libraries. RESULTS: Within the enriched wheat cDNA repertoire we identified, among others, the sequence encoding wheat thioredoxin-hB (Triticum aestivum allergen 25 [Tri a 25]). The recombinant protein displayed enzymatic activity, and we observed a sensitization rate of 47% among bakers with occupational asthma and of 35% among patients with grass pollen allergy, but without a clinical history of cereal allergy. Furthermore, the previously characterized maize thioredoxin-h1 (Zea mays allergen 25 [Zea m 25]), sharing 74% identity with Tri a 25, exhibited distinct IgE cross-reactivity with its wheat homologue. Two bakers also showed sensitization to human thioredoxin, which shares 29% identity with Tri a 25. In a comparative study, we included recombinant alpha-amylase inhibitor 0.19, showing a sensitization rate of 65% in individuals with baker's asthma. CONCLUSION: Thioredoxins represent a novel family of cross-reactive allergens that might contribute to the symptoms of baker's asthma and might in addition be related to grass pollen allergy, as indicated by the reactivity of grass pollen allergic patients to cereal thioredoxins. CLINICAL IMPLICATIONS: The recombinant cereal thioredoxins will, together with the already reported wheat allergens, contribute to a more reliable diagnosis of baker's asthma and, perhaps, become a tool for the development of component-resolved immunotherapy.

Allergens↗
PubMed2006

Food allergy.

This article reviews the classification of food allergies, their prevalence, pathophysiology, diagnosis, treatment and prognosis.

Diet Records↗
PubMed2006

A novel approach for investigation of specific and cross-reactive IgE epitopes on Bet v 1 and homologous food allergens in individual patients.

BACKGROUND: A clinically relevant allergic reaction requires recognition of at least two different epitopes on the surface of the allergen by IgE. These epitopes may be specific or cross-reactive. Moreover, patterns of IgE reactivity may be patient-specific. The aim of our study was to compare specific and cross-reactive IgE epitopes and epitope patterns between individual patients. We used Bet v 1-related food allergy as a model. METHODS: Five patients were investigated by cross-competitive ELISA for specific and cross-reacting IgE to Bet v 1, and its homologues Gly m 4 (soybean), Ara h 8 (peanut), and Pru av 1 (cherry). Allergen-specific as well as cross-reactive IgE epitopes were assessed by competitive immunoscreening of a phage-displayed random 7-mer peptide library using polyclonal purified IgE from individual sera. The resulting peptide mimics were mapped on the surface of the 3D-structure of the allergens using a computer-based algorithm. RESULTS: Competitive immunoscreening and epitope mapping identified patient-specific IgE epitope patterns. However, one IgE-binding surface area that was recognized by all patients and two recognized by three patients were identified on all four proteins. These results are consistent with the determination of IgE cross-reactivity of the individual patients' sera against the four recombinant allergens by cross-competitive ELISA. CONCLUSIONS: Selection of phage-displayed peptide mimics with serum IgE from allergic patients in combination with computer-based mapping of the peptide mimics onto the surface of the three-dimensional allergen structure is a promising novel tool to investigate IgE epitope specificity in individual patients. Such basic information on epitope structure may be used for prediction of cross-reactivity and potential allergenicity of novel foods.

2S Albumins, Plant↗
PubMed2006

Component-resolved diagnostics in food allergy.

PURPOSE OF REVIEW: The purpose of this paper is to review and discuss recent studies on component-resolved diagnostics in food allergy, involving panels of pure allergen molecules or arrays of peptides derived from allergen sequences, and to summarize the reporting of new food allergens during the past 2 years. RECENT FINDINGS: Several component-resolved diagnostic studies in food allergy suggest that the use of panels of allergen molecules may allow refined clinical information to be obtained on the likelihood or severity of an allergic food reaction and regarding diagnostic specificity. Further, in some studies the use of pure allergen molecules has led to a clearly higher sensitivity of the immunoglobulin E immunoassay compared with conventional allergen extracts. SUMMARY: While common diagnostic methods in allergy assess the presence or absence of allergen-specific sensitization, to date, no in-vitro or in-vivo test exists which exhibits full correlation with clinical food allergy. A multitude of recently reported findings and observations indicate that molecular analysis of allergen sensitization pattern may serve to enhance the clinical utility of immunoglobulin E antibody-based allergy diagnostics. Pure natural and recombinant allergen molecules as well as panels of synthetic peptides have been used for this purpose.

Allergens↗
PubMed2005

The oral allergy syndrome: improved diagnostic and treatment methods.

PURPOSE OF REVIEW: The aim of this article is to review recent clinical and molecular findings related to the oral allergy syndrome in order to define its relevance in the field of food allergy, describe current diagnostic approaches and discuss attempts to use specific immunotherapy for treatment. RECENT FINDINGS: New allergenic sources causing the oral allergy syndrome have been reported. Their allergenic molecules have been identified. In most of those studies oral allergy syndrome is reported as a clinical manifestation among more severe ones. Some of the molecules generally considered not to be at risk for severe reactions have been demonstrated to pose a threat for inducing generalized reactions. Some studies tried to assess the usefulness of immunotherapy with birch pollen extract by either subcutaneous or sublingual routes for the treatment of associated food allergies. In most of the cases, a well defined study design and a molecular approach at different study levels are lacking and thus the value of the obtained results is limited. To date, no final conclusion can be drawn on the basis of reported results. SUMMARY: The knowledge about the highly prevalent phenomenon of oral allergy syndrome is still incomplete, in respect to both, epidemiology and foods inducing symptoms. It is very important to reach consensus on several aspects of this food-induced allergic disease. Further studies are required to highlight whether immunotherapy using co-recognized inhalant allergens is an effective way of curative treatment, or if co-treatment with purified pollen-related food allergens will be required to obtain a long-lasting effect.

Desensitization, Immunologic↗
PubMed2004

Hazelnut (Corylus avellana) vicilin Cor a 11: molecular characterization of a glycoprotein and its allergenic activity.

In Europe, hazelnuts (Corylus avellana) are a frequent cause of food allergies. Several important hazelnut allergens have been previously identified and characterized. Specific N-glycans are known to induce strong IgE responses of uncertain clinical relevance, but so far the allergenic potential of glycoproteins from hazelnut has not been investigated. The aim of the study was the molecular characterization of the glycosylated vicilin Cor a 11 from hazelnut and the analysis of its allergenic activity. Although MALDI-TOF (matrix-assisted laser-desorption ionization-time-of-flight) MS showed that one of two potential glycosylation sites of Cor a 11 was glycosylated, CD spectroscopy indicated that recombinant and natural Cor a 11 share similar secondary structures. Thus to analyse the impact of the glycan residues of Cor a 11 on IgE binding, the allergenic activity of natural glycosylated Cor a 11 and recombinant Cor a 11 was compared. In addition, the IgE sensitization pattern to recombinant Cor a 11, Cor a 1, Cor a 2 and Cor a 8 of 65 hazelnut allergic patients was determined in vitro. The prevalence of IgE reactivity to hazelnut vicilin Cor a 11 was below 50%. Basophil histamine-release assays were used to determine the allergenic activity of both natural and recombinant Cor a 11 in comparison with Cor a 1, a birch (Betula verrucosa) pollen-related major hazelnut allergen. Both forms of Cor a 11 induced mediator release from basophils to a similar extent, indicating that the hazelnut allergic patients had cross-linking IgE antibodies binding to the protein backbone and not to carbohydrate structures. In comparison to Cor a 1, a 10000-fold higher concentration of Cor a 11 was required to induce similar basophil mediator release. In conclusion, the hazelnut vicilin Cor a 11 is a minor allergen both in regard to prevalence and allergenic potency, whereas its glycan does not contribute to its allergenic activity.

Allergens↗
PubMed2004

Soybean allergy in patients allergic to birch pollen: clinical investigation and molecular characterization of allergens.

BACKGROUND: Allergic reactions to legumes are generally thought to be acquired by means of primary sensitization through the gastrointestinal tract. Recently, Gly m 4 (starvation-associated message 22), a Bet v 1-related pathogenesis-related protein 10 from soy, was suggested to be an allergen in patients with allergic reactions to a dietary product containing a soy protein isolate. OBJECTIVE: We sought to evaluate the clinical relevance of Gly m 4 in subjects allergic to birch pollen with soy allergy and to assess the risk for subjects allergic to birch pollen to acquire soy allergy. METHODS: Twenty-two patients allergic to birch pollen with soy allergy confirmed by means of positive double-blind, placebo-controlled food challenge results (n = 16) or a convincing history (n = 6) were investigated for IgE reactivity to birch pollen and soy allergens by using the Pharmacia CAP system and immunoblot analysis. Cross-reactivity was assessed by means of enzyme allergosorbent test inhibition. Ninety-four patients with birch pollen allergy were interviewed to assess soy tolerance and screened for IgE reactivity to Gly m 4 by means of immunoblotting. The Gly m 4 content in soy foods and soybean varieties was investigated by means of quantitative evaluation of immunoblots. RESULTS: During double-blind, placebo-controlled food challenge, 10 patients experienced symptoms localized to the oral cavity, and 6 patients had a more severe reaction. CAP analysis revealed Gly m 4-specific IgE in 96% (21/22) of the patients. All patients had Bet v 1-specific IgE antibodies, and 23% (5/22) had positive Bet v 2 results. In IgE immunoblotting 25% (6/22) of the patients recognized soy profilin (Gly m 3), and 64% (14/22) recognized other soy proteins. IgE binding to soy was at least 80% inhibited by birch pollen and 60% inhibited by rGly m 4 in 9 of 11 sera tested. Seventy-one percent (67/94) of highly Bet v 1-sensitized patients with birch pollen allergy were sensitized to Gly m 4, and 9 (9.6%) of those patients reported soy allergy. The Gly m 4 content in soy products ranged between 0 and 70 ppm (milligrams per kilogram). CONCLUSIONS: Our results confirm that soybean is another birch pollen-related allergenic food. Gly m 4 is the major soy allergen for patients allergic to birch pollen with soy allergy. The content of Gly m 4 in soy food products strongly depends on the degree of food processing.

Adolescent↗
PubMed2004

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

BACKGROUND: We recently described patients with soybean allergy mainly mediated by cross-reactivity to birch pollen allergens. A majority of those patients were reported to have peanut allergy. OBJECTIVE: We sought to study the occurrence of peanut allergy in patients allergic to birch pollen and characterized the Bet v 1-homologous peanut allergen Ara h 8. METHODS: Recombinant Ara h 8 was cloned with degenerated primers and expressed in Escherichia coli. Nine Swiss and 11 Dutch patients with peanut and birch pollen allergy and a positive double-blind, placebo-controlled food challenge result to peanut were investigated for IgE reactivity to birch pollen and purified peanut allergens and cross-reactivity between birch and peanut. Ara h 8 stability against digestion and roasting was assessed by means of RAST inhibition. The IgE cross-linking potency of Ara h 8 was tested on the basis of basophil histamine release. RESULTS: During double-blind, placebo-controlled food challenge, all patients experienced symptoms in the oral cavity, progressing to more severe symptoms in 40% of patients. CAP-FEIA detected recombinant (r) Ara h 8-specific IgE in 85%. IgE binding to Ara h 8 was inhibited by Bet v 1 in peanut extract immunoblotting and in RAST inhibition. In EAST inhibition recombinant rAra h 8 inhibited IgE binding to peanut in 4 of 7 tested patient sera. Antipeanut response was dominated by Ara h 8 in 12 of 17 tested patients. Furthermore, our results demonstrate a low stability of Ara h 8 to roasting and no stability to gastric digestion. Basophil histamine release with rAra h 8 was more than 20% in 5 of 7 tested sera. CONCLUSIONS: Peanut allergy might be mediated in a subgroup of our patients by means of cross-reaction of Bet v 1 with the homologous peanut allergen Ara h 8.

Adolescent↗
PubMed2003

Immediate-type hypersensitivity reaction to ingestion of mycoprotein (Quorn) in a patient allergic to molds caused by acidic ribosomal protein P2.

BACKGROUND: Quorn is the brand name for a line of foods made with so-called "mycoprotein," which springs from the mold Fusarium venenatum. Since the introduction on the food market, there have been complaints from consumers reporting adverse gastrointestinal reactions after ingestion of mycoprotein. To date, it is not clear whether the reported symptoms are IgE-mediated. OBJECTIVE: The aim of the study was to describe for the first time a case history of an asthmatic patient with severe hypersensitivity reactions to ingested mycoprotein and to identify and characterize the potential allergen that might be responsible for this. METHODS: The sensitization pattern of the asthmatic subject was characterized, and food allergy to mycoprotein was assessed by double-blinded placebo-controlled food challenge. Afterward, specific IgE antibodies of the serum of this patient were used to screen a Fusarium culmorum cDNA expression library. The coding sequence of one enriched cDNA-clone was expressed in Escherichia coli to produce a recombinant protein that was further purified and immunologically characterized. RESULTS: The patient showed high sensitization to many known aeroallergens but apart from Quorn not to any other tested food samples. The deduced amino acid sequence of the enriched cDNA-clone (Fus c 1) showed large identity to the 60S acidic ribosomal protein P2 which is highly conserved among several species and also described as minor allergen in other mold species. The frequency of IgE reactivity of sera from F culmorum -sensitized subjects to rFus c 1 was approximately 35%. By enzyme allergosorbent test inhibition, we found 65% inhibition of mycoprotein IgE reactivity by rFus c 1. On the opposite we found reduced IgE reactivity of rFus c 1 of 68% by using mycoprotein as inhibitor. CONCLUSIONS: Sensitization to mold allergens by the respiratory tract and subsequent oral ingestion of cross-reactive proteins may lead to severe food-allergic reactions. Thus, the 60S acidic ribosomal protein P2 of F venenatum probably is the reason for the described severe hypersensitivity reactions of the patient to Quorn-mycoprotein because of its potential cross-reactivity to the F culmorum allergen Fus c 1.

Adult↗
PubMed2002

Heterogeneity of banana allergy: characterization of allergens in banana-allergic patients.

BACKGROUND: Banana is a frequent cause of food allergy, particularly in latex-sensitized patients. OBJECTIVE: The aim of the study was to get insights in immunoglobulin (Ig)E antibody responses of patients with a history of allergic reaction to banana but not to latex. METHODS: In four patients who complained about symptoms after banana consumption, skin prick tests (SPTs) with aeroallergens, latex, banana, avocado, and kiwi were performed. Total and specific serum IgE to birch pollen, rBet v 1 and rBet v 2, latex, banana, avocado, and kiwi were determined by the CAP method (Pharmacia Diagnostics, Uppsala, Sweden). Allergens were identified by immunoblotting with banana extract and recombinant banana profilin. Two patients underwent double-blind, placebo-controlled food challenges (DBPCFC) with banana. RESULTS: All patients showed a positive SPT to banana, and three were IgE-CAP positive (> or = class 2). Two patients were also sensitized (SPT and CAP) to latex, avocado, kiwi, and birch pollen. In the immunoblot these two patients' sera reacted to 32- to 34-kDa proteins, which had already been described as major banana allergens. In both patients banana allergy was confirmed by DBPCFC. The third patient also had a sensitization to avocado, but not to latex or pollen. Immunoblot analysis detected a single band at 70 kDa. The fourth patient was sensitized to birch pollen, rBet v 1 and rBet v 2, but not to latex. Immunoblot analysis in this patient's serum was positive with recombinant banana profilin. CONCLUSIONS: The relevance of banana as a source of food allergy was confirmed in two patients by DBPCFC. In 1 of 2 patients, in whom banana allergy was not a consequence of latex sensitization, a 70-kDa protein was identified as a banana allergen, and in the other patient profilin was detected as a putative cross-reactive allergen.

Adolescent↗
PubMed2002

Identification of hazelnut major allergens in sensitive patients with positive double-blind, placebo-controlled food challenge results.

BACKGROUND: The hazelnut major allergens identified to date are an 18-kd protein homologous to Bet v 1 and a 14-kd allergen homologous to Bet v 2. No studies have reported hazelnut allergens recognized in patients with positive double-blind, placebo-controlled food challenge (DBPCFC) results or in patients allergic to hazelnut but not to birch. OBJECTIVE: We characterized the hazelnut allergens by studying the IgE reactivity of 65 patients with positive DBPCFC results and 7 patients with severe anaphylaxis to hazelnut. METHODS: Hazelnut allergens were identified by means of SDS-PAGE and IgE immunoblotting. Further characterization was done with amino acid sequencing, evaluation of the IgE-binding properties of raw and roasted hazelnut with enzyme allergosorbent test inhibition, assessment of cross-reactivity with different allergens by means of immunoblotting inhibition, and purification by means of HPLC. RESULTS: All the sera from the patients with positive DBPCFC results recognized an 18- and a 47-kd allergen; other major allergens were at molecular weights of 32 and 35 kd. Binding to the 18-kd band was inhibited by birch extract, indicating its homology with the birch major allergen, and abolished in roasted hazelnut. The 47-kd allergen is a sucrose-binding protein, the 35-kd allergen is a legumin, and the 32-kd allergen is a 2S albumin. Patients with severe anaphylactic reactions to hazelnut showed specific IgE reactivity to a 9-kd allergen, totally inhibited by purified peach lipid-transfer protein (LTP), which was heat stable and, when purified, corresponded to an LTP. CONCLUSIONS: The major allergen of hazelnut is an 18-kd protein homologous to Bet v 1, and the 9-kd allergen is presumably an LTP. Other major allergens have molecular weights of 47, 32, and 35 kd.

Allergens↗
PubMed2002

Component-resolved diagnosis with recombinant allergens in patients with cherry allergy.

BACKGROUND: In pollen-related food allergy, extracts for skin prick tests (SPTs) are often not standardized, and the test reliability is affected by false-negative reactions. OBJECTIVE: We sought to evaluate a panel of recombinant allergens (RAs) derived from one allergenic food for use in component-resolved in vivo diagnosis, taking cherry as a model food. METHODS: Seventy-nine subjects were included in the study: 24 Swiss patients (group 1) with a positive double-blind placebo-controlled food challenge result to cherries, 23 patients with birch pollen allergy but without cherry allergy (group 2), 23 nonatopic subjects (group 3), and 9 Spanish patients with a history of a cherry allergy (group 4). SPTs were performed in duplicate by using recombinant cherry allergens (Bet v 1-related allergen: recombinant (r) Pru av 1; profilin: rPru av 4; and lipid transfer protein: rPru av 3) in concentrations of 10, 50, and 100 microg/mL. Furthermore, IgE reactivity to rPru av 1, rPru av 4, and rPru av 3 was assessed by means of immunoblot analysis. RESULTS: SPT responses with rPru av 1, rPru av 4, and rPru av 3 were positive in 92%, 17%, and 4% of the patients in group 1; in 74%, 30%, and 0% of the patients in group 2; in 0%, 22%, and 89% of the patients in group 4; and negative for all nonatopic subjects (group 3). Thus the sensitivity of a positive SPT response to at least one of the 3 RAs was 96%. The specificities, negative predictive values, and positive predictive values with the 3 RAs were 100%, 96%, and 100% if calculated in relation to the nonatopic control group but 17%, 79%, and 60% when calculated in relation to the control group with birch pollen allergy. The correlation between SPT and immunoblotting results was excellent. Sensitization to rPru av 3 was associated with more severe symptoms than sensitization to rPru av 1. CONCLUSIONS: SPTs with RAs proved to be highly sensitive for diagnosis of cherry allergy. Component-resolved in vivo diagnosis with standardized amounts of stable RAs allows us to determine sensitization patterns directly, to correlate them with severity of clinical symptoms, and to analyze geographic differences.

Adolescent↗