Fabacées et bouleau

	Recrutement / sélection	Autres allergies / histoires cliniques (HC)	Tests cutanés et/ou in vitro
13 (dont 1 enfant) (Allemagne)	CAP+ soja		CAP+ arachide 6
101 (Allemagne)	HC+ cerise	HC+ arachide 36 soja 6
20 adultes (Allemagne)	isolat de soja (all. sévère 13)		CAP+ soja 12 bouleau 16
31 adultes (Pays-Bas)	TPODA+ noisette	HC+ arachide 11
142 patients (Suisse, Allemagne)	pollinose bouleau		rGly m 4+ 32%
22 adultes (Suisse, Allemagne)	soja (TPODA+ ou A chez 18)	HC+ arachide 12 pois 2 haricot 1	TC+ lupin 5
94 adultes (Suisse, Allemagne)	CAP rBet v 1 > 17kU	HC+ soja 9
20 adultes (Allemagne)	TPODA+ arachide		CAP+ Ara h 8 17
1 adulte (France)	HC+ lait de soja		TC+ bouleau TC nég. pousse soja
10 adultes (Suisse, Allemagne	HC+ pousses soja	HC+ soja 10 arachide 5
426 patients (Autriche)	TC+ bouleau	HC+ (chez consomm.) lait de soja : 22%	TC+ natif lait de soja 20% TC+ commercial soja 5%
38 adultes (Pays Bas)	TC+ arachide	TPODA+ lupin 35% HC+ pois 29% HC+ soja 33%	TC+ lupin 82% pois 55% soja 87%
28 adultes (Portugal)	TC+ lupin (11 bouleau+)	HC+ lupin 5 arachide 0	TC+ arachide 12 haricot 13 pois chiche 13 fève 9 pois 8 soja 8 lentille 7
25 adultes et 5 enfants (Suisse, Italie, Danemark)	TPODA+ soja (ou anaphylaxie 5)	HC+ arachide 20	TC+ natif arachide 48%
6 adultes (Pays Bas)	TPODA+ lupin (4 bouleau+)	HC+ arachide 3 (avec HC+ soja 2/3, pois 1/3) : tous bouleau+
5 adultes (Japon)	HC+ soja		Bet v 1+ 5 Gly m 4+ 3

[1] - Kleine-Tebbe J, Wangorsch A, Vogel L, Crowell DN, Haustein UF, Vieths S. Severe oral allergy syndrome and anaphylactic reactions caused by a Bet v 1-related PR-10 protein in soybean, SAM22. J Allergy Clin Immunol 2002;110:797-804

BACKGROUND: Anaphylactic reactions to soy products have been attributed to stable class 1 food allergens . OBJECTIVE: IgE- mediated reactions to a soy-containing dietary food product in patients allergic to birch pollen were investigated . METHODS: Detailed case histories were taken from 20 patients. Their sera were analyzed for IgE (UniCAP) specific for birch, grass, mugwort, the recombinant birch allergens rBet v 1 and rBet v2, and soy protein. Extracts from birch pollen, soy isolate, rBet v 1, and the recombinant PR-10 soy protein rSAM22 were coupled to paper disks or nitrocellulose for IgE measurements (enzyme allergosorbent test) or Western blot analysis. Enzyme allergosorbent testing, Western blot inhibition, and histamine release studies were performed with the same allergens . RESULTS: Most patients (17/20) experienced facial, oropharyngeal, and/or systemic allergic symptoms within 20 minutes after ingesting the soy product for the first time. Birch pollen allergy (16/20) was common, along with oral allergy syndrome to apple (12/20) or hazelnut (11/20). IgE levels to birch and Bet v 1 but not to other inhalants were high in 18 of 20 patients. Significant IgE binding to rSAM22 occurred in 17 of 20 patients. Blot experiments with the soy isolate revealed IgE-binding bands at 17 kd (15/20), 22 kd (1/20), and 35 to 38 kd (2/20); the former was inhibited by preincubation of the sera with rBet v 1 or rSAM22. Birch extract and soy isolate, rBet v 1, and rSAM22 induced dose-dependent histamine release in the nanomolar range . CONCLUSION: Immediate-type allergic symptoms in patients with birch pollen allergy after ingestion of soy protein-containing food items can result from cross-reactivity of Bet v 1 -specific IgE to homologous pathogenesis-related proteins, particularly the PR-10 protein SAM22.

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[2] - Mittag D, Akkerdaas J, Ballmer-Weber BK, Vogel L, Wensing M, Becker WM, et al. Ara h 8, a Bet v 1–homologous allergen from peanut, is a major allergen in patients with combined birch pollen and peanut allergy. J Allergy Clin Immunol 2004;114:1410-1417

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 1ˆhomologous peanut allergen Ara h 8. Method s : 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. Result s : 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 8ˆspecific 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.

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[3] - Mittag D, Vieths S, Vogel L, Wagner-Loew D, Starke A, Hunziker P, et al. Birch pollen-related food allergy to legumes: identification and characterization of the Bet v 1 homologue in mungbean (Vigna radiata), Vig r 1. Clin Exp Allergy 2005;35:1049-1055

BACKGROUND: Recently allergic reactions to legumes mediated by Bet v 1-homologous food allergens were described for soy and peanut. In this study we assessed allergic reactions to another legume, to mungbean seedlings, and identified its Bet v 1-homologous allergen Vig r 1 . METHODS: Ten patients were selected who had a history of allergic reactions to mungbean seedlings and a respiratory allergy to birch pollen. The Bet v 1 homologue in mungbean seedlings, Vig r 1, was cloned by a PCR strategy, expressed in Escherichia coli, and purified by preparative SDS-PAGE. In all sera, specific IgE against birch pollen, Bet v 1, Bet v 2, Vig r 1, and the Bet v 1 homologues in soy (Gly m 4) and cherry (Pru av 1) was determined by CAP-FEIA. Cross-reactivity of specific IgE with Vig r 1, Bet v 1, Gly m 4, and Pru av 1 was assessed by immunoblot inhibition. Expression of Vig r 1 during development of mungbean seedlings and under wounding stress was analysed by immunoblotting. The Vig r 1 double band was analysed by matrix-assisted laser desorption/ionization time-of-flight and liquid chromatography/tandem mass spectrometry (LC/MS/MS) . RESULTS: All patients were sensitized to birch pollen and Bet v 1, 20% to Bet v 2, and 90% to Gly m 4. Seventy percent of the patients showed IgE binding to a double band at 15 kDa in mungbean extract that was inhibited after pre-incubation of sera with rBet v 1. PCR cloning revealed that the mungbean homologue of Bet v 1 had a molecular weight of 16.2 kDa, a calculated pI of 4.6% and 42.8% amino acid sequence identity with Bet v 1. MS analysis confirmed similarity of the double band with the deduced Vig r 1 sequence, but also indicated the existence of other Vig r 1 isoforms. ImmunoCAP analysis detected IgE against Vig r 1 in 80% of the sera. IgE binding to Vig r 1 was inhibited with Gly m 4 in six of six and with rPru av 1 in four of six patients. Vig r 1 expression occurred during development of seedlings and was increased by wounding stress . CONCLUSIONS: Food allergy to mungbean seedlings can be caused by primary sensitization to birch pollen and is mediated by Vig r 1 in the majority of the patients with birch pollen-related allergy to mungbean seedlings.

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[4] - Rihs HP, Chen Z, Rueff F, Petersen A, Rozynek P, Heimann H, et al. IgE binding of the recombinant allergen soybean profilin (rGly m 3) is mediated by conformational epitopes. J Allergy Clin Immunol 1999;104:1293-1301

Soybean proteins are constituents of a number of food products and represent a panel of potential allergens. Thus far, little is known about the molecular characteristics of soybean allergens. OBJECTIVE: The aim of this study was to identify the soybean profilin by PCR-based complementary (c)DNA cloning and to elucidate its allergenic characteristics. METHODS: Highly degenerate profilin-specific primers were used to identify, by means of PCR, 2 soybean profilin isoforms (GmPRO1 and GmPRO2) by using soybean cDNA as a target. One isoform (GmPRO1) with a length of 394 bp corresponding to 131 amino acid residues was subcloned and expressed in fusion with the maltose-binding protein. Moreover, 3 overlapping recombinant soybean profilin fragments comprising amino acid residues 1-65, 38-88, and 50-131 were also prepared as maltose-binding protein fusion proteins. IgE-binding reactivity of the recombinant proteins and the cross-reactivity of soybean profilin with birch profilin was studied by immunoblotting, enzyme-linked allergosorbent assays (EASTs), and competitive inhibition experiments by using serum samples from 13 soybean-sensitized subjects. RESULTS: Results of immunoblot analysis, EAST, and EAST-inhibition experiments indicate the presence of profilin in soybean extract. The recombinant soybean profilin (rGly m 3) was recognized by IgE in 9 (69%) of the 13 sera tested. Only the full-length rGly m 3 was able to bind with IgE antibodies, whereas the 3 soybean profilin fragments did not show significant binding reactivity, indicating that the IgE binding to rGly m 3 depends on the integrity of a conformational structure, which was not present in the overlapping profilin fragments. The rGly m 3 cross-reacted with birch pollen profilin (Bet v 2), and the IgE binding to Bet v 2 could be inhibited by rGly m 3. CONCLUSIONS: rGly m 3 represents a new soybean allergen with well-characterized primary sequence, and its IgE-binding reactivity is mediated by conformational epitopes.

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[5] - Scheurer S, Pastorello EA, Wangorsch A, Kästner M, Haustein D, Vieths S. Recombinant allergens Pru av 1 and Pru av 4 and a newly identified lipid transfer protein in the in vitro diagnosis of cherry allergy. J Allergy Clin Immunol 2001;107:724-731

BACKGROUND: In central and northern Europe food allergy to fruits of the Rosaceae family is strongly associated with birch pollinosis because of the existence of IgE cross-reactive homologous allergens in birch pollen and food. By contrast, in the Mediterranean population allergic reactions to these fruits frequently are not related to birch pollen allergy and are predominantly elicited by lipid transfer proteins (LTPs). OBJECTIVE: We sought to determine the prevalence of IgE sensitization to the recombinant cherry allergens Pru av 1 and Pru av 4 in comparison with cherry extract within a representative group of patients who were allergic to cherries recruited in Germany and to compare the relevance of IgE to cherry LTPs in Italian patients. METHODS: Recombinant Pru av 1 and rPru av 4 were available from earlier studies. The cDNA of the cherry LTPs was obtained by using a PCR-cloning strategy. The protein was expressed in Escherichia coli and purified by means of metal chelate affinity chromatography. Sera from 101 German patients with birch pollinosis and oral allergy syndrome to cherry and sera from 7 Italian patients with cherry allergy were investigated by using enzyme allergosorbent tests for IgE reactivity with cherry extract, rPru av 1, rPru av 4, and the recombinant cherry LTP. Inhibition experiments were performed to compare the IgE reactivity of natural and recombinant cherry LTPs and to investigate potential cross-reactivity with birch pollen allergens. RESULTS: The LTP from cherry comprises 91 amino acids and a 26 amino acid signal peptide. The mature cherry LTP shows high amino acid sequence identity with allergenic LTPs from peach (Pru p 3, 88%), apricot (Pru ar 3, 86%), and maize (Zea m 14, 59%) and displays no IgE cross-reactivity with birch pollen. The IgE prevalences in the German patients were as follows: LTP, 3 of 101 (3%); rPru av 1, 97 of 101 (96.0%); rPru av 4, 16 of 101 (16.2%); and cherry extract, 98 of 101 (97%). All 7 Italian patients had IgE against the cherry LTP. CONCLUSIONS: Recombinant allergens are useful tools for a more accurate in vitro IgE-based diagnosis of cherry allergy. Taken together, they mimic the allergenic activity of cherry extract, having slightly higher biologic activity. Sensitization to the cherry LTP is relevant for a minority of patients recruited in Germany, but our data indicate that it may be a major allergen in Italy.

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[6] - Kleine-Tebbe J, Wangorsch A, Vogel L, Crowell DN, Haustein UF, Vieths S. Severe oral allergy syndrome and anaphylactic reactions caused by a Bet v 1-related PR-10 protein in soybean, SAM22. J Allergy Clin Immunol 2002;110:797-804

BACKGROUND: Anaphylactic reactions to soy products have been attributed to stable class 1 food allergens . OBJECTIVE: IgE- mediated reactions to a soy-containing dietary food product in patients allergic to birch pollen were investigated . METHODS: Detailed case histories were taken from 20 patients. Their sera were analyzed for IgE (UniCAP) specific for birch, grass, mugwort, the recombinant birch allergens rBet v 1 and rBet v2, and soy protein. Extracts from birch pollen, soy isolate, rBet v 1, and the recombinant PR-10 soy protein rSAM22 were coupled to paper disks or nitrocellulose for IgE measurements (enzyme allergosorbent test) or Western blot analysis. Enzyme allergosorbent testing, Western blot inhibition, and histamine release studies were performed with the same allergens . RESULTS: Most patients (17/20) experienced facial, oropharyngeal, and/or systemic allergic symptoms within 20 minutes after ingesting the soy product for the first time. Birch pollen allergy (16/20) was common, along with oral allergy syndrome to apple (12/20) or hazelnut (11/20). IgE levels to birch and Bet v 1 but not to other inhalants were high in 18 of 20 patients. Significant IgE binding to rSAM22 occurred in 17 of 20 patients. Blot experiments with the soy isolate revealed IgE-binding bands at 17 kd (15/20), 22 kd (1/20), and 35 to 38 kd (2/20); the former was inhibited by preincubation of the sera with rBet v 1 or rSAM22. Birch extract and soy isolate, rBet v 1, and rSAM22 induced dose-dependent histamine release in the nanomolar range . CONCLUSION: Immediate-type allergic symptoms in patients with birch pollen allergy after ingestion of soy protein-containing food items can result from cross-reactivity of Bet v 1 -specific IgE to homologous pathogenesis-related proteins, particularly the PR-10 protein SAM22.

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[7] - Wensing M, Penninks AH, Hefle SL, Akkerdaas JH, van Ree R, Koppelman SJ, et al. The range of minimum provoking doses in hazelnut-allergic patients as determined by double-blind, placebo-controlled food challenges. Clin Exp Allergy 2002;32:1757-1762

Background The risk for allergic reactions depends on the sensitivity of individuals and the quantities of offending food ingested. The sensitivity varies among allergic individuals, as does the threshold dose of a food allergen capable of inducing an allergic reaction. Objective : This study aimed at determining the distribution of minimum provoking doses of hazelnut in a hazelnut-allergic population. Method s : Thirty-one patients with a history of hazelnut-related allergic symptoms, a positive skin prick test to hazelnut and/or an elevated specific IgE level, were included. Double-blind, placebo-controlled food challenges (DBPCFC) were performed with seven increasing doses of dried hazelnut (1 mg to 1 g hazelnut protein) randomly interspersed with seven placebo doses. Result s : Twenty-nine patients had a positive challenge. Itching of the oral cavity and/or lips was the first symptom in all cases. Additional gastrointestinal symptoms were reported in five patients and difficulty in swallowing in one patient. Lip swelling was observed in two patients, followed by generalized urticaria in one of these. Threshold doses for eliciting subjective reactions varied from a dose of 1 mg up to 100 mg hazelnut protein (equivalent to 6.4-640 mg hazelnut meal). Extrapolation of the dose-response curve showed that 50% of our hazelnut-allergic population will suffer from an allergic reaction after ingestion of 6 mg (95% CI, 2-11 mg) of hazelnut protein. Objective symptoms were observed in two patients after 1 and 1000 mg, respectively. Conclusion : DBPCFCs demonstrated threshold doses in half of the hazelnut-allergic patients similar to doses previously described to be hidden in consumer products. This stresses the need for careful labelling and strategies to prevent and detect contamination of food products with hazelnut residues.

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[8] - Zuidmeer L, Bolhaar S, Knulst A, van Leeuwen WA, Aalbers M, Krebitz M, et al. Severe symptoms caused by thaumatin-like proteins in foods: a result of primary sensitization to birch pollen ? EAACI 22th Congress, Paris, 7-11 June, 2003, Poster n°196

Background: It has almost become a dogma that birch pollen-related food allergies are always mild, because Bet v 1 and its homologues from foods as well as profilins are extremely heat and protease-sensitive. Protease-resistant birch pollen allergens have so far not been reported. Methods: A panel of 477 sera from The Netherlands with >2.0 IU/ml of specific IgE against apple were analysed by RAST for specific IgE against 4 apple allergens: nMal d 1, rMal d 2 (thaumatin-like protein [TLP]), nMal d 3 (LTP) and nMal d 4 (profilin). rMal d 2-positive sera (>0.7 IU/ml) were further analysed by RAST inhibition with (protease-digested) birch pollen extract. Serum from a patient with severe food-related anaphylaxis was studied in more detail by RAST(-inhibition) and immunoblot(- inhibition). Results: As expected most sera contained significant titers of specific IgE against Mal d 1 (70% with > 1.0 IU/ml). Frequency of recognition of Mal d 2, 3 and 4 was much lower (23%, 9% and 19% respectively). For 55 sera with a clear positive RAST for rMal d 2 IgE-binding to this allergen was inhibited with birch pollen extract. On average the Mald 2 RAST was inhibited by 75%, indicating that birch pollen extract contains a crossreactive structure with food TLP. A similar inhibition was observed with protease-digested birch pollen extract, suggesting that the putative TLP-related allergen from birch pollen is extremely protease resistant. This observation fits with the high degree of stability observed for rMal d 2 in simulated gastric fluid. Considering this stability, it is not surprising that among the patients with TLP-specific IgE antibodies, severe food allergic symptoms were observed. One of these patients was further analysed in depth. This patient experienced anaphylactic shock upon consumption of hazelnut liquor, raspberry and several other fruits on different occasions. IgE binding to raspberry and several other foods could be inhibited by birch pollen and by rMal d 2 in both RAST- and immunoblot-inhibition, indicating that the severe food allergy of this patient is caused by TLP-like allergens and that sensitisation is most likely birch pollen driven. Conclusion: Birch pollen contain an allergen that is crossreactive with food TLPs and is most likely responsible for sensitisation. In contrast to most Bet v 1-related allergens, food TLPs can cause severe food allergy.

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[9] - Mittag D, Vieths S, Vogel L, Becker WM, Rihs HP, Helbling A, et al. Soybean allergy in patients allergic to birch pollen: Clinical investigation and molecular characterization of allergens. J Allergy Clin Immunol 2004;113:148-154

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[10] - Mittag D, Akkerdaas J, Ballmer-Weber BK, Vogel L, Wensing M, Becker WM, et al. Ara h 8, a Bet v 1–homologous allergen from peanut, is a major allergen in patients with combined birch pollen and peanut allergy. J Allergy Clin Immunol 2004;114:1410-1417

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 1ˆhomologous peanut allergen Ara h 8. Method s : 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. Result s : 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 8ˆspecific 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.

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[11] - Vigan M, Girardin P, Rame JM, Pelletier F. Bronchospasme au tonyu: découvertes déconcertantes à propos d'un cas. Rev Fr Allergol Immunol Clin 2005;45:276-277

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[12] - Mittag D, Vieths S, Vogel L, Wagner-Loew D, Starke A, Hunziker P, et al. Birch pollen-related food allergy to legumes: identification and characterization of the Bet v 1 homologue in mungbean (Vigna radiata), Vig r 1. Clin Exp Allergy 2005;35:1049-1055

BACKGROUND: Recently allergic reactions to legumes mediated by Bet v 1-homologous food allergens were described for soy and peanut. In this study we assessed allergic reactions to another legume, to mungbean seedlings, and identified its Bet v 1-homologous allergen Vig r 1 . METHODS: Ten patients were selected who had a history of allergic reactions to mungbean seedlings and a respiratory allergy to birch pollen. The Bet v 1 homologue in mungbean seedlings, Vig r 1, was cloned by a PCR strategy, expressed in Escherichia coli, and purified by preparative SDS-PAGE. In all sera, specific IgE against birch pollen, Bet v 1, Bet v 2, Vig r 1, and the Bet v 1 homologues in soy (Gly m 4) and cherry (Pru av 1) was determined by CAP-FEIA. Cross-reactivity of specific IgE with Vig r 1, Bet v 1, Gly m 4, and Pru av 1 was assessed by immunoblot inhibition. Expression of Vig r 1 during development of mungbean seedlings and under wounding stress was analysed by immunoblotting. The Vig r 1 double band was analysed by matrix-assisted laser desorption/ionization time-of-flight and liquid chromatography/tandem mass spectrometry (LC/MS/MS) . RESULTS: All patients were sensitized to birch pollen and Bet v 1, 20% to Bet v 2, and 90% to Gly m 4. Seventy percent of the patients showed IgE binding to a double band at 15 kDa in mungbean extract that was inhibited after pre-incubation of sera with rBet v 1. PCR cloning revealed that the mungbean homologue of Bet v 1 had a molecular weight of 16.2 kDa, a calculated pI of 4.6% and 42.8% amino acid sequence identity with Bet v 1. MS analysis confirmed similarity of the double band with the deduced Vig r 1 sequence, but also indicated the existence of other Vig r 1 isoforms. ImmunoCAP analysis detected IgE against Vig r 1 in 80% of the sera. IgE binding to Vig r 1 was inhibited with Gly m 4 in six of six and with rPru av 1 in four of six patients. Vig r 1 expression occurred during development of seedlings and was increased by wounding stress . CONCLUSIONS: Food allergy to mungbean seedlings can be caused by primary sensitization to birch pollen and is mediated by Vig r 1 in the majority of the patients with birch pollen-related allergy to mungbean seedlings.

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[13] - Jung P, Sesztak-Greinecker G, Wantke F, Goetz M, Jarisch R, Hemmer W. Prevalence of cross-sensitisation to soy allergens in patients with birch pollen allergy and allergenicity of different soy products. EAACI 25th Congress, Vienna, 10-14 June, 2006, Poster n°1530

Background: Soybean Gly m 4, a member of the PR-10 protein family, has been recognized as a cross-reactive food allergen in birch pollen-related food hypersensitivity with the potential to elicit severe systemic reactions. We investigated the prevalence of cross-sensitisation to soybean and the allergenicity of various soy-based food items in patients with birch pollen allergy. Method: A commercial brand of soy milk was added to our routine skin prick test panels and tested in consecutive patients with suspect inhalant or food allergy. Consumption habits concerning soy products and eventual adverse reactions were recorded by questionnaire. Additional prick-to-prick testing with different soy products was done in selected patients. Results: Among 292 patients with a positive skin prick test to birch pollen, 72 (24.7%) reacted to soy milk but only 18 (6.2%) reacted to a commercial soy skin prick test. 34/97 (35%) of birch pollen-allergic patients reported to have knowingly consumed soy milk before with 11/34 (31%) of them having experienced side effects. Mild reactions to tofu and soybean sprouts were occasionally reported. Prick-to-prick testing with different soy products in 16 patients with a positive skin test to soy milk revealed positive reactions to raw and cooked soybean sprouts (94%/50%), raw and cooked tofu (87%/40%), soy dessert (86%), and soy joghurt (21%). No significant differences in skin test responses were seen between seven different brands of soy milk (protein content 3.0-3.7g/100ml). Skin tests remained positive even after boiling soy milk für 5, 10 and 30 minutes. Conclusions: Cross-sensitisation to soy is frequent among patients with birch pollen allergy and many soy-based foods retain considerable allergenicity. As soy products are becoming increasingly popular on the market, birch pollen-allergic patients may be at growing risk of experiencing allergic reactions to these products.

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[14] - Peeters KABM, Koppelman SJ, Penninks AH, Lebens A, Bruijnzeel-Koomen CAFM, Hefle SL et al. Clinical relevance of sensitization to lupine in peanut-sensitized adults. Allergy 2009;64:549-555

BACKGROUND: The use of lupine in food has been increasing during the last decade and allergic reactions to lupine have been reported, especially in peanut-allergic patients. The frequency and the degree of cross-reactivity to other legumes are not known. The aim of the study was to investigate the frequency of sensitization to lupine, and in addition to pea and soy, and its clinical relevance, in peanut-sensitized patients. Furthermore, to determine the eliciting dose (ED) for lupine using double-blind placebo-controlled food challenges (DBPCFC) . METHODS: Thirty-nine unselected peanut-sensitized patients were evaluated by skin prick tests (SPT) and ImmunoCAP to lupine, pea, and soy. Clinical reactivity was measured by DBPCFC for lupine, and by history for pea and soy . RESULTS: Eighty-two percent of the study population was sensitized to lupine, 55% to pea, and 87% to soy. Clinically relevant sensitization to lupine, pea, or soy occurred in 35%, 29%, and 33% respectively of the study population. None of the patients was aware of the use of lupine in food. The lowest ED for lupine, inducing mild subjective symptoms, was 0.5 mg, and the no observed adverse effect level (NOAEL) was 0.1 mg. No predictive factors for lupine allergy were found . CONCLUSION: In peanut-sensitized patients, clinically relevant sensitization to either lupine or to pea or soy occurs frequently. The ED for lupine is low (0.5 mg), which is only fivefold higher than for peanut. Patients are not aware of lupine allergy and the presence of lupine in food, indicating that education is important to build awareness.

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[15] - Reis AM, Fernandes NP, Marques SL, Paes MJ, Sousa S, Carvalho F, et al. Lupine sensitisation in a population of 1,160 subjects. Allergol Immunopathol (Madr) 2007;35:162-163

Lupin is part of the Mediterranean diet and is also used as a thickener of food products. It has been recognised as a cause of serious allergic reactions. This study aims at determining the prevalence of lupin sensitisation in 1,160 subjects consulting allergologists. This population performed skin prick tests (SPT) to lupin. In case of positivity, a clinical questionnaire was applied and the subjects were tested for other legumes, common inhalants and latex. We find a 4.1% sensitisation rate to lupin, a 75% co-sensitisation between lupin and legumes, a 82.1% co-sensitisation between lupin and pollen and a 28.5% co-sensitisation between lupin and latex. To conclude, we documented a high lupin sensitisation in a selected population, thus stressing the importance of lupin as a food allergen.

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[16] - Ballmer-Weber BK, Holzhauser T, Scibilia J, Mittag D, Zisa G, Ortolani C, et al. Clinical characteristics of soybean allergy in Europe: A double-blind, placebo-controlled food challenge study. J Allergy Clin Immunol 2007;119:1489-1496

BACKGROUND: Soybean is a relevant allergenic food, but little is known about individual threshold doses in soy allergy . OBJECTIVE: We sought to determine the clinical characteristics of soy allergy in Europe, including a dose-response curve . METHODS: Patients with a history of soy allergy underwent a titrated, double-blind, placebo-controlled food challenge. A statistical model was used to calculate the risk of allergic consumers to experience an allergic reaction to soy. Sera were analyzed for specific IgE to soy, peanut, Bet v 1, and Gly m 4 . RESULTS: All patients but one responded primarily with subjective symptoms to the challenge followed by objective symptoms in 11 subjects, ranging from rhinitis up to a decrease in blood pressure. Cumulative threshold doses for allergic reactions ranged from 10 mg to 50 g for subjective symptoms and from 454 mg to 50 g for objective symptoms. The pattern of IgE reactivity against proteins with molecular weights of between approximately 10 and 70 kd was highly individual among the patients and did not correlate with the severity of symptoms . CONCLUSIONS: When data are fitted by using a normal distribution statistical model, they predict that 1% of patients with soy allergy would react subjectively and objectively with 0.21 and 37.2 mg of soy protein, respectively. CLINICAL IMPLICATIONS: Both the clinical and immunologic basis of soy allergy in Europe are highly complex, which affects the diagnosis of soy allergy and the advice given to patients with soy allergy in regard to risk management.

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[17] - Peeters KABM, Nordlee JA, Penninks AH, Chen L, Goodman RE, Bruijnzeel-Koomen CAFM, et al. Lupine allergy: Not simply cross-reactivity with peanut or soy. J Allergy Clin Immunol 2007;120:647-653

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.

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[18] - Inomata N, Sjolander S, Tatewaki S, Ikezawa Z. Microarray Analysis Of Allergen-specific IgE Detection Using Multiple Purified And Recombinant Soy Allergens Involved With Class 1 And Class 2 Food Allergy. J Allergy Clin Immunol 2008;121:S248

RATIONALE: The purpose of this study was to investigate whether a microarray-based immunoassay of soy allergen-specific IgE detection using recombinant and purified soy allergens would be useful to differentiate two classes of food allergy, i.e. class 1 food allergens that cause sensitization through the gastrointestinal tract, and class 2 allergens, which have no capacity for sensitization and cross-react to aeroallergens. METHODS: Serum of 5 adult patients with soy allergy were analyzed using a microarray along with soy class 1 allergens containing glycinin, bconglycinin, GlymTI, GlymBd30K, and Glym4 as a soy class 2 allergen, peanuts allergens, such as Ara h 1-3, and 8, and pollen allergens, such as Bet v 1 and Phl p 12. RESULTS: In the microassay, three patients showed positive response to Gly m 4, whereas all 5 patients showed negative response to all class 1 soy allergens. Positive response to Bet v 1 and Phl p 12 were found in five and two patients, respectively. In addition, all patients who were asymptomatic after ingestion of peanuts showed positive responses to some peanuts allergens. These results suggested that three of the 5 patients could be diagnosed with class 2 allergy due to soy because of negativity for class 1 soy allergens and positivity for class 2 soy allergens and pollen allergens, such as Bet v 1 and Phl p 12. CONCLUSIONS: The microassay including all relevant allergens involved with two class food allergy could be useful for differentiating the class of plant-derived food allergy. Funding: Grant-in -aid for scientific

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[19] - - Noisette. Alim'Inter 2002;7:169-170

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[20] - Ballmer-Weber BK, Holzhauser T, Scibilia J, Mittag D, Zisa G, Ortolani C, et al. Clinical characteristics of soybean allergy in Europe: A double-blind, placebo-controlled food challenge study. J Allergy Clin Immunol 2007;119:1489-1496

BACKGROUND: Soybean is a relevant allergenic food, but little is known about individual threshold doses in soy allergy . OBJECTIVE: We sought to determine the clinical characteristics of soy allergy in Europe, including a dose-response curve . METHODS: Patients with a history of soy allergy underwent a titrated, double-blind, placebo-controlled food challenge. A statistical model was used to calculate the risk of allergic consumers to experience an allergic reaction to soy. Sera were analyzed for specific IgE to soy, peanut, Bet v 1, and Gly m 4 . RESULTS: All patients but one responded primarily with subjective symptoms to the challenge followed by objective symptoms in 11 subjects, ranging from rhinitis up to a decrease in blood pressure. Cumulative threshold doses for allergic reactions ranged from 10 mg to 50 g for subjective symptoms and from 454 mg to 50 g for objective symptoms. The pattern of IgE reactivity against proteins with molecular weights of between approximately 10 and 70 kd was highly individual among the patients and did not correlate with the severity of symptoms . CONCLUSIONS: When data are fitted by using a normal distribution statistical model, they predict that 1% of patients with soy allergy would react subjectively and objectively with 0.21 and 37.2 mg of soy protein, respectively. CLINICAL IMPLICATIONS: Both the clinical and immunologic basis of soy allergy in Europe are highly complex, which affects the diagnosis of soy allergy and the advice given to patients with soy allergy in regard to risk management.

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[21] - Holzhauser T, Petrovskaya O, Kuehne Y, Wangorsch A, Ballmer-Weber B, Bindslev-Jensen C, et al. Allergenicity of soybean beta-conglycinin versus Gly m Bd 30k in patients with confirmed soybean allergy. EAACI 25th Congress, Vienna, 10-14 June, 2006, Poster n°513

Background: Soybean b-conglycinin and Gly m Bd 30k have been described as IgE-binding proteins, the latter one as putative major soybean allergen. We aimed at characterising both soybean proteins in regard to their relevance in a European patient group with confirmed soybean allergy. Methods: Twenty-five adults were included into the study on the basis of a positive DBPCFC or conclusive history of anaphylaxis to soy. Twenty-two children were included upon positive DBPCFC or open oral challenge. Natural b-conglycinin subunits (a, a', b) were extracted from soybean, recombinant subunits expressed in E.coli, and both purified by continuous-elution electrophoresis. Natural Gly m Bd 30k was enriched by an oleosin fractionation of soybean and the recombinant homologue expressed as His-tagged fusion protein in E.coli and purified by IMAC. Protein identity was proven by N-terminal sequencing and/or peptide mass fingerprinting. IgE-reactivity of the purified soy proteins was investigated by IgE-immunoblotting and/or IgE-ELISA with patients' sera. ELISA- and EAST-inhibition, and mediator release from passively sensitized humanized rat basophilic leukaemia cells was performed with selected patients' sera. Results: b-conglycinin was IgE-reactive in 54 % (12/22) of the children and 20 % (5/25) of the adults. By contrast, enriched natural Gly m Bd 30k bound IgE from less than 50 % of patients‚ sera in immunoblotting, and rGly m Bd 30k did not show any IgE-reactivity. In ELISA-inhibition, IgE-binding to b- conglycinin was fully inhibited by soybean extract and itself. IgE-reactivity to b-conglycinin was almost fully inhibited by peanut extract and purified Ara h 1 in a soybean and peanut allergic patient, however hardly inhibited in a patient allergic to soybean but not to peanut. Similar results were obtained in EAST-inhibition with soybean extract on the solid surface. Specific mediator release confirmed the cross-linking properties of b-conglycinin. Conclusion: In Europe, soybean b-conglycinin is a major allergen for soy-allergic children and an important minor allergen in adults, whereas the relevance of Gly m Bd 30k in IgE-mediated soybean allergy remains unclear and demands further investigation. In some patients cross-reactivity between peanut and soybean is limited.

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[22] - Holzhauser T, Ballmer-Weber B, Bindslev-Jensen C, Scibilia J, Zisa G, Ortolani C, et al. Identification of Soybean Allergens With Sera From Subjects Having a Positive DBPCFC or History of Anaphylaxis to Soy. J Allergy Clin Immunol 2005;115(2 suppl.):S38

RATIONALE: Soybean belongs to the „big eight‰ allergenic foods. The identification and characterization of soy allergens helps to improve diagnosis METHODS: 28 patients from Switzerland, Denmark and Italy were included on the basis of a positive DBPCFC (n=23) or a history of anaphylaxis to soy (n=5). IgE-reactive peptides were identified from a soybean cDNA expression library. Full-length purified recombinant and natural soybean allergens, and soyflakes extract were investigated in IgE-immunoblotting RESULTS: From the cDNA library the major storage proteins glycinin (A1aB1b, A2B1a), and the 3 subunits of beta-conglycinin were IgE-reactive Patients‚ IgE bound to recombinant and natural glycinin (>20%), to recombinant and natural beta-conglycinin (>20%), to natural (>50%) but not to recombinant Gly m Bd 30k CONCLUSIONS: The IgE-binding profiles in soyflakes extract were complex and highly individual. Purified natural and recombinant soy proteins improved identification of IgE-reactive soy proteins. Glycosylation and/or folding properties seem to influence IgE-binding of Gly m Bd 30k that is thought to be a major soybean allergen

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[23] - Mittag D, Vieths S, Vogel L, Becker WM, Rihs HP, Helbling A, et al. Soybean allergy in patients allergic to birch pollen: Clinical investigation and molecular characterization of allergens. J Allergy Clin Immunol 2004;113:148-154

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[24] - Mittag D, Akkerdaas J, Ballmer-Weber BK, Vogel L, Wensing M, Becker WM, et al. Ara h 8, a Bet v 1–homologous allergen from peanut, is a major allergen in patients with combined birch pollen and peanut allergy. J Allergy Clin Immunol 2004;114:1410-1417

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 1ˆhomologous peanut allergen Ara h 8. Method s : 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. Result s : 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 8ˆspecific 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.

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[25] - Jacquenet S, Moneret-Vautrin DA, Parisot L, Saint-Martin F, Rame JM, Saint-Cast MC, et al. Anaphylaxies sévères au lait de soja médiées par Gly m 4 : une augmentation d’incidence ? Enquête du réseau allergovigilance. Rev Fr Allergol Immunol Clin 2008;48:456-458

L‚anaphylaxie alimentaire au soja est peu fréquente. Le réseau d‚allergovigilance a colligé sept cas durant les deux dernières années. Ces réactions sévères présentent la particularité d‚être survenues à la suite d‚ingestion de boissons à base de lait de soja chez des patients non allergiques à l‚arachide. La recherche d‚IgE spécifiques par ImmunoCap® soja (Phadia) est négative dans cinq sur sept cas, inférieure à 0,7kU/l dans deux cas. Un taux fort d‚IgE spécifiques anti-Gly m 4 est mis en évidence dans quatre cas avec négativité du Cap® au soja. Les auteurs discutent sur la façon de conduire le diagnostic biologique d‚une allergie au soja chez des sujets sensibilisés à Bet v 1. Ils soulignent que la sensibilisation croisée à un homologue de Bet v 1 peut engendrer une anaphylaxie sévère. Il n‚est pas actuellement possible de déterminer s‚il y a une augmentation de l‚incidence de ce type d‚allergie ou si des cas émergent, grâce à la mise à disposition de l‚ImmunoCap® rGly m 4.

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[26] - Mortz CG, Andersen KE, Bindslev-Jensen C. The prevalence of peanut sensitization and the association to pollen sensitization in a cohort of unselected adolescents – The Odense Adolescence Cohort Study on Atopic Diseases and Dermatitis (TOACS). Pediatr Allergy Immunol 2005;16:501-506

In the last decade an increased occurrence of peanut hypersensitivity and severe anaphylactic reactions to peanut have been reported. However, few prevalence studies have been performed in unselected populations. This study evaluated the point prevalence of peanut hypersensitivity in Danish adolescents. The point prevalence of peanut allergy confirmed by oral challenge was estimated to 0.5%. The number of adolescents sensitized to peanut by specific immunoglobulin E (IgE) (CAP FEIA) and skin prick test (SPT) were higher (5.8% resp. 3.4%). In adolescents without clinically relevant peanut sensitization most cases were sensitized to grass pollen and the IgE class for grass was higher than for peanut. A correlation between peanut and pollen (grass) sensitization is therefore plausible. Before a positive SPT or specific IgE measurement to peanut is considered clinically relevant in a patient, the case history should be evaluated together with examination for pollen sensitization.

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[27] - Boehncke WH, Loeliger C, Kuehnl P, Kalbacher H, Bohm BO, Gall H. Identification of HLA-DR and -DQ alleles conferring susceptibility to pollen allergy and pollen associated food allergy. Clin Exp Allergy 1998;28:434-441

BACKGROUND: Allergenic crossreactivity of pollen and foods due to the antigeneic similarity of oligopeptides is a well established clinical phenomenon. OBJECTIVE: To determine the immunopathological relevance of antigen presentation, we analysed the HLA class-II genotype of patients with either pollen allergy or pollen associated food allergy. METHODS: One hundred and twenty patients with pollen allergy and 80 patients with pollen associated food allergy were evaluated by skin- prick tests, RAST, and HLA class-II genotyping. The control population comprised 4251 healthy blood and bone marrow donors. RESULTS: Monovalent pollen allergy was observed in 57% (n=68) of patients with pollinosis (57x grass pollen, 11x birch pollen), but only in 15% (n=12) of patients with food allergy (9x grass pollen, 3x birch pollen). Hazelnut (71%), almond (65%), walnut (44%) and apple (41%) were the most common food allergens and frequently associated with birch pollen allergy. Grass pollen allergy was associated with an increased frequency of HLA-DQB1*0301 (RR=2.3; EF=0.4; P=0.0016) when compared with the control population. HLA-DRB *08 conferred a sixfold higher risk for peanut allergy (EF=0.3; P=0.0013) and -DRB1*12 a 13-fold higher risk for carrot allergy (EF=0.3; P<0.000001). The differences on allele frequencies detected among patients with food allergies diminished or turned statistically insignificant when their genotypes were directly compared to those of patients with the corresponding pollen allergies. This was found in the case of birch pollen associated hazel nut allergy for the extended haplotype HLA-DRB1*01, -DQA1*0101, -DQB1*0501 as well as in grass pollen associated peanut allergy for HLA-DRB1*08 (from RR=6, P=0.0013 to insignificant) and in birch pollen associated carrot allergy for HLA-DRB1*12 (from RR=13, P < 0.000001 to insignificant). CONCLUSION: We were able to identify HLA class-II alleles associated with some allergies thus indicating that these alleles might confer susceptibility to the respective allergens. Similarities at the level of the HLA class-II genotype parallel the empirical finding of distinct cross-reactivity patterns thus complementing investigations of IgE specificities. Our observations provide evidence for the major importance of antigen presentation on the manifestation of distinct crossreactivity patterns.

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[28] - Wensing M, Akkerdaas JH, van Leeuwen A, Stapel SO, Bruijnzeel-Koomen CAFM, Aalberse RC, et al. IgE to Bet v 1 and profilin: Crossreactivity patterns and clinical relevance. J Allergy Clin Immunol 2002;110:435-442

BACKGROUND: Individuals with pollen allergy often have IgE against plant-derived foods. This can be due to cross-reactive IgE against Bet v 1 and homologues, profilins, and/or cross-reactive carbohydrate determinants . OBJECTIVE: The aim of this study was to correlate sensitization to Bet v 1 and profilin with individual recognition patterns to plant foods and clinical relevance . METHODS: Fifty-two patients with pollen allergy and IgE against at least one plant-derived food were included in the study. Adverse reactions to plant-derived foods were documented by using standardized interviews. Skin prick tests were performed for pollen (grass, birch, and mugwort) and 14 plant-derived foods. In addition, recombinant (r) Bet v 1 and rBet v 2 (profilin) were tested intracutaneously. Specific IgE against the abovementioned allergens were determined by means of RAST. Cross-reactivity was studied by means of RAST inhibition . RESULTS: Eighty-five percent of patients were sensitized to Bet v 1, and 71% were sensitized to profilin. Profilin was associated with a higher number of positive RAST results to plant-derived foods than Bet v 1. In contrast, Bet v 1 was associated with more positive skin prick test responses and more food-related symptoms. Sensitization to Bet v 1 was associated with IgE against apple, hazelnut, and peach, whereas sensitization to profilin was associated with positive RAST results to all investigated plant-derived foods except apple, peach, and melon . CONCLUSIONS: IgE antibodies against Bet v 1 have a more limited spectrum of cross-reactivity than those against profilin, but they frequently give rise to clinically relevant cross-reactivities to food. In analogy to anticarbohydrate IgE, cross-reactive IgE against food profilins have no or very limited clinical relevance.

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[29] - de Martino M, Novembre E, Cozza G, de Marco A, Bonazza P, Vierruci A. Sensitivity to tomato and peanut allergens in children monosensititized to grass pollen. Allergy 1988;43:206-213

Possible associations between allergy to grass pollen and positive skin tests to food allergens were studied in 102 children monosensitized (as to inhalant allergens) to grass pollen, and in 117 children monosensitized (as to inhalant allergens) to Dermatophagoides. Thirty-two foods were tested by an epicutaneous method. Positive skin tests to food allergens were more frequent in children with allergy to grass pollen (59.8%) than in children with allergy to Dermatophagoides (9.4%). A considerably high frequency of positive reactions to tomato (39.2%), peanut (22,5%), green pea (13.7%), and wheat (11.7%) was observed in children with allergy to grass pollen. Positive skin tests to peanut closely correlated with positive RAST results and nasal provocation tests, whereas in children with skin test positivity to tomato a close correlation with nasal provocation tests but a 45% correlation with a positive RAST result were observed. RAST inhibition experiments were carried out, and the results may suggest the presence of cross-reacting IgE to grass pollen, tomato, and peanut antigens. Clinical implications of these findings are discussed in the light of histories of food hypersensitivity, urticaria-angioedema, and atopic dermatitis in children with allergy to grass pollen.

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[30] - Mittag D, Batori V, Neudecker P, Wiche R, Friis EP, Ballmer-Weber BK, et al. A novel approach for investigation of specific and cross-reactive IgE epitopes on Bet v 1 and homologous food allergens in individual patients. Mol Immunol 2006;43:268-278

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.

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[31] - Mittag D, Vieths S, Vogel L, Wagner-Loew D, Starke A, Hunziker P, et al. Birch pollen-related food allergy to legumes: identification and characterization of the Bet v 1 homologue in mungbean (Vigna radiata), Vig r 1. Clin Exp Allergy 2005;35:1049-1055

BACKGROUND: Recently allergic reactions to legumes mediated by Bet v 1-homologous food allergens were described for soy and peanut. In this study we assessed allergic reactions to another legume, to mungbean seedlings, and identified its Bet v 1-homologous allergen Vig r 1 . METHODS: Ten patients were selected who had a history of allergic reactions to mungbean seedlings and a respiratory allergy to birch pollen. The Bet v 1 homologue in mungbean seedlings, Vig r 1, was cloned by a PCR strategy, expressed in Escherichia coli, and purified by preparative SDS-PAGE. In all sera, specific IgE against birch pollen, Bet v 1, Bet v 2, Vig r 1, and the Bet v 1 homologues in soy (Gly m 4) and cherry (Pru av 1) was determined by CAP-FEIA. Cross-reactivity of specific IgE with Vig r 1, Bet v 1, Gly m 4, and Pru av 1 was assessed by immunoblot inhibition. Expression of Vig r 1 during development of mungbean seedlings and under wounding stress was analysed by immunoblotting. The Vig r 1 double band was analysed by matrix-assisted laser desorption/ionization time-of-flight and liquid chromatography/tandem mass spectrometry (LC/MS/MS) . RESULTS: All patients were sensitized to birch pollen and Bet v 1, 20% to Bet v 2, and 90% to Gly m 4. Seventy percent of the patients showed IgE binding to a double band at 15 kDa in mungbean extract that was inhibited after pre-incubation of sera with rBet v 1. PCR cloning revealed that the mungbean homologue of Bet v 1 had a molecular weight of 16.2 kDa, a calculated pI of 4.6% and 42.8% amino acid sequence identity with Bet v 1. MS analysis confirmed similarity of the double band with the deduced Vig r 1 sequence, but also indicated the existence of other Vig r 1 isoforms. ImmunoCAP analysis detected IgE against Vig r 1 in 80% of the sera. IgE binding to Vig r 1 was inhibited with Gly m 4 in six of six and with rPru av 1 in four of six patients. Vig r 1 expression occurred during development of seedlings and was increased by wounding stress . CONCLUSIONS: Food allergy to mungbean seedlings can be caused by primary sensitization to birch pollen and is mediated by Vig r 1 in the majority of the patients with birch pollen-related allergy to mungbean seedlings.

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[32] - Mittag D, Akkerdaas J, Ballmer-Weber BK, Vogel L, Wensing M, Becker WM, et al. Ara h 8, a Bet v 1–homologous allergen from peanut, is a major allergen in patients with combined birch pollen and peanut allergy. J Allergy Clin Immunol 2004;114:1410-1417

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 1ˆhomologous peanut allergen Ara h 8. Method s : 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. Result s : 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 8ˆspecific 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.

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[33] - Mittag D, Batori V, Neudecker P, Wiche R, Friis EP, Ballmer-Weber BK, et al. A novel approach for investigation of specific and cross-reactive IgE epitopes on Bet v 1 and homologous food allergens in individual patients. Mol Immunol 2006;43:268-278

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.

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Rubriques

Dans la même rubrique

Les Fabacées : généralités

Le lupin

Le soja

L’arachide

Réactivités croisées entre Fabacées

Fabacées et LTP