La pomme de terre

[1] - García González MC, González Mendiola MR, Prieto Montaño P, Muñoz Martín T, Martín C, de la Hoz Caballer B. Asthma and rhinoconjunctivitis induced by potato and green bean aeroallergens. EAACI 21th Congress, Naples, 1-5 June, 2002, Poster n°280

Background: Vegetables can cause allergic symptoms after being ingested. Less frecuently their allergens act as inhalants inducing rhinoconjunctivitis and asthmatic attacks. The most affected patients are housewives whose problems usually start at the age of 30-40 years. They often have a previous history of pollinic rhinoconjunctivitis or asthma and cooked vegetables do not cause them any symptom. Method: We describe the cases of two pollinic women whith a history of rhinoconjunctivitis and asthma due to vegetable aeroallergens. The first one referred these symptoms when peeling potatoes, and the second one when peeling green beans. Both could eat the vegetable implicated if it had been cooked before. Several test were performed including skin prick test ( with raw and boiled potatoe/green bean and with some extracts prepared in our laboratory), specific IgE antibodies, rub-test, bronchial provocation, challenge test and SDS-PAGE-immunoblotting. Results: First patient: The result of the skin prick test with raw potatoe was positive, but negative with boiled potatoe. The specific Ig E was 5 KU/l for peel and 9 KU/l for pulp. Rub test with the potatoes on the patient's forearm elicited wheals and pruritus whithin 5 minutes. Challenge test was positive (rhinoconjunctivitis), and SDS-PAGE-immunoblotting showed several peptidic bands of 100,47,38.5,33.5,29 and 26KDa. Second patient: The result of the skin prick test with raw green bean was positive, but negative with boiled green bean. The specific Ig E was 13 KU/l . Bronchial provocation was positive and immunoblotting showed peptidic bands of 78,72,50.4 and 17.3 KDa. Conclusion: We present two cases in which vegetable aeroallergens cause symptoms of rhinoconjunctivitis and asthma in two patients who however are able to eat the vegetable involved without any problem. Most of the few patients described presenting this syndrome present previous pollinic symptoms and get worse in the pollinic season when peeling the implicated vegetables. These facts lead us to think about a common allergen between pollens and the vegetables implicated. According to the results of the immunoblotting peptidic bands, it seems to be a high molecular weight protein. The allergen is still unknown.

↩

[2] - de Swert LF, Cadot P, Ceuppens JL. Allergy to cooked white potatoes in infants and young children: A cause of severe, chronic allergic disease. J Allergy Clin Immunol 2002;110:524-529

BACKGROUND: Cases of allergy to cooked potato in children have been reported, some with immediate and others with late reactions. The clinical effects of chronic allergic reactions to potato and the effectiveness of diet on such reactions have not been described previously. OBJECTIVE: We sought to evaluate the importance of cooked potato as an allergenic food in individual cases of atopy in children. METHODS: Eight atopic children were selected on the basis of suspicion of allergy to cooked potatoes: all had potato-specific IgE, 2 of 8 had experienced immediate allergic reactions, and 6 of 8 had eczema that improved with a potato-elimination diet (decrease in severity scoring of atopic dermatis [SCORAD] index of >50%). The patients were evaluated by using skin prick tests with homemade cooked and noncooked potato extracts and with a commercial extract and by using IgE immunoblots from SDS-PAGE patterns of potato extract. Seven patients were challenged with cooked potato. The control group consisted of 9 age-matched atopic children, 8 of them with eczema. RESULTS: The mean SCORAD index decreased from 43.3 before to 11.5 after elimination of potato from the diet. Potato CAP values ranged from 3.71 to greater than 100 kUa/L. Potato challenge results were positive in 7 of 7 patients. Skin prick test responses were positive for cooked potato extracts in 7 of 7 patients, for noncooked extracts in 7 of 7 patients, and for the commercial extract in 8 of 8 patients compared with in 0 of 9, 1 of 9, and 1 of 9 subjects in the control group, respectively. During immunoblotting, 8 of 8 patient sera recognized one or more protein bands compared with 0 of 9 control subject sera. CONCLUSION: Allergy to cooked potatoes is a cause of severe allergic disease, with immediate reactions and eczema in some atopic infants and young children.

↩

[3] - Majamaa H, Seppälä U, Palosuo T, Turjanmaa K, Kalkkinen N, Reunala T. Positive skin and oral challenge responses to potato and occurrence of IgE antibodies to patatin (Sol t 1) in infants with atopic dermatitis. Pediatr Allergy Immunol 2001;12:283-288

The clinical significance and molecular specificity of hypersensitivity reactions to raw and cooked potatoes remain ambiguous. We therefore investigated the clinical hypersensitivity to raw and cooked potato in infants suspected to have potato allergy and compared the findings with the occurrence of immunoglobulin E (IgE) antibodies to patatin (Sol t 1), characterized as the primary allergen of potato. Twelve infants (10 to 24 months of age) suffering from atopic dermatitis (AD) and suspected to have adverse reactions to potato, were examined. As a skin exposure test we used rubbing with both raw and cooked potato, and used open oral challenge with cooked potato for 7 days. A special eczema scoring system (SCORAD) was used to assess the severity of symptoms and signs of AD. Skin-prick tests (SPTs) were performed with raw potato and natural Sol t 1, and serological studies included measurement of total serum IgE and IgE antibodies to Sol t 1, and potato radioallergosorbent testing (RAST). The skin-rubbing test with raw potato was positive in seven (58%) and the oral challenge positive in eight (67%) infants. One infant presented with an immediate reaction and seven with a delayed reaction, i.e. exacerbation of AD, after oral challenge responses to cooked potato. Nine (75%) infants had IgE antibodies to Sol t 1 in enzyme-linked immunosorbent assay (ELISA), and SPT to natural Sol t 1 was positive in six (50%) potato-allergic infants. In conclusion, we observed positive challenge responses to both raw and cooked potato in food-allergic atopic infants. The presence of IgE antibodies and concomitant positive SPTs to the heat-stable potato allergen, Sol t 1, suggest that cooked potato can be an allergenic food for infants suffering from AD

↩

[4] - Beausoleil JL, Spergel JM, Pawlowski NA. Anaphylaxis to raw potato. Ann Allergy Asthma Immunol 2001;86:68-70

BACKGROUND: Potato allergy has been described rarely, generally in relation to the Oral Allergy Syndrome (OAS). Adults with seasonal allergic rhinitis have been reported in whom peeling of raw potatoes causes oculonasal symptoms, wheezing, and contact urticaria. Skin testing with fresh fruits and vegetables has been recommended in cases of OAS, although the sensitivity of commercial potato extract is reportedly equal to that of fresh potato. CASE REPORT: This report describes a 4-year-old with raw potato-induced anaphylaxis. He rapidly developed urticaria, angioedema, respiratory distress, vomiting and diarrhea after biting into a raw potato that was being used for painting in preschool. Review of systems is significant for viral-induced wheezing, but no symptoms suggestive of seasonal allergic rhinitis were evident. His mother has a history of seasonal allergic rhinitis and contact urticaria with raw potato. Skin testing to commercial potato extract was negative and skin testing to fresh potato by the prick + prick method was markedly positive. Skin testing to birch tree was negative. An open challenge to a small amount of cooked potato was negative. Food challenge to raw potato was not considered indicated in this case of immediate anaphylaxis to a single food. CONCLUSIONS: This patient had clinical and skin test reactivity to raw and uncooked potato in the absence of OAS. The patient will be followed for the development of seasonal allergic rhinitis.

↩

[5] - Seppälä U, Majamaa H, Turjanmaa K, Vanto T, Kalkkinen N, Palosuo T, et al. Frequent skin prick test sensitivity to soy and potato in children: cross-reactivity to structurally related allergens? EAACI 21th Congress, Naples, 1-5 June, 2002, Poster n°217

Background: Frequency of allergic reactions to soy is growing. A number of soy proteins including Kunitz-type soybean trypsin inhibitor (KSTI) have been identified as allergens. Allergy to potato is also increasingly recognized, implying occurrence of IgE abntibodies to Sola t 2-4 members of the KSTI family. The purpose was to study the frequency of positive skin prick test (SPT) reactions to soy and potato in atopic children and examine whether the allergens can be cross-reactive. METHODS: 177 children (age <4 years) suspected for food allergy were prick tested with soybean and fresh potato. Sera from 17 children suspected for potato and 12 children for soy allergy were examined with ELISA for IgE antibodies to natural Sola t 2-4 and KSTI. Results: 10/177 (5%) children had positive SPT to soybean and 14 (7%) to potato. In ELISA, most (70%) potato SPT positive children showed IgE antibodies to KSTI and 75% had a positive soybean RAST. On the other hand, 9 (75%) children suspected for soy allergy had IgE antibodies to Sola t 2-4. A marked crosswise ELISA inhibition was evident for Sola t 2-4 and KSTI allergens. CONCLUSION: Children with suspected food allergy show frequently positive SPT to soybean and potato. Positive SPT and RAST to soybean may be due to cross-reactive IgE antibodies against structurally realted potato allergens, and vice versa. This cross-reactivity should be taken in account when examining children suspected for soy or potato allergy.

↩

[6] - Lee SK, Ye YM, Yoon SH, Lee BO, Kim SH, Park HS. Evaluation of the sensitization rates and identification of IgE-binding components in wild and genetically modified potatoes in patients with allergic disorders. Clin Mol Allergy 2006;4:10

ABSTRACT: BACKGROUND: The potato is one of the most common types of genetically modified (GM) food. However, there are no published data evaluating the impact of genetic manipulations on the allergenicity of GM potatoes. To compare the allergenicity of GM potatoes with that of wild-type potatoes using in vivo and in vitro methods in adult allergy patients sensitized to potatoes. METHODS: A total of 1886 patients with various allergic diseases and 38 healthy controls participated in the study. Skin-prick testing and IgE-ELISA were carried out with extracts prepared from wild-type and GM potatoes. An ELISA inhibition test was used to confirm the binding specificity. IgE-binding components in extracts from the two types of potato were identified by SDS-PAGE and IgE-immunoblotting. The effects of digestive enzymes and heat on the allergenicity of the extracts was evaluated by preincubating the potatoes with or without simulated gastric and intestinal fluids in the absence or presence of heat. RESULTS: Positive responses (ratio of the wheal size induced by the allergen to that induced by histamine (A/H) greater than or equal to 2+) to wild-type or GM potato extracts, as demonstrated by the skin-prick test, were observed in 108 patients (5.7%). Serum-specific IgE was detected in 0-88% of subjects who tested positively. ELISA inhibition tests indicated significant inhibition when extract from each type of potato was added. IgE-immunoblot analysis demonstrated the presence of 14 IgE-binding components within the wild-type potato and 9 within the GM potato, Furthermore, a common 45-kDa binding component that yielded similar IgE-binding patterns was noted in more than 80% of the reactions using sera from patients sensitized to wild-type or GM potato. Exposure to simulated gastric fluid and heat treatment similarly inhibited IgE binding by extracts from wild-type and GM potatoes, whereas minimal changes were obtained following exposure of the extracts to simulated intestinal fluid . CONCLUSION: Our results strongly suggest that genetic manipulation of potatoes does not increase their allergenic risk. The sensitization rate of adult allergy patients to both types of extract was 5.7%, and a common major allergen (45 kDa) was identified.

↩

[7] - Majamaa H, Seppälä U, Palosuo T, Reunala T, Kalkkinen N, Turjanmaa K. Hypersensitivity to Raw Potatoes in Adults. AAAAI 58th Annual Meeting, New York, 1-6 March, 2002, Poster n°659

Previous studies have shown that hypersensitivity reaction between raw and cooked potatoes (Solanum tuberosum) are substantially different. Young infants and children suffering from food allergies may develop allergy to cooked potatoes showing specific IgE to heat-stabile potato allergens, Sola t 1-4. In general, however, hypersensitivity reactions to raw potatoes are associated with atopic adults frequently showing positive skin prick test (SPT) to birch (Betula verrucosa) pollen. Immunological basis for this phenomenon has considered to result from IgE-mediated cross-reactivity between heat-labile pollen and potato allergens. Allergic reactions to raw potatoes are usually immediate, appearing within minutes after peeling and/or handling of them. The clinical spectrum includes symptoms ranging from contact urticaria and itching of hands to non-cutaneous symptoms such as rhinitis and wheezing. In the present study 9 adults (ranging from 15 to 46 years) showing clinical history of hypersensitivity against raw potatoes were examined. Total and potato specific IgE was measured by RAST (Pharmacia, Sweden) and all the patients were SPT with purified potato allergens, Sola t 1-4, raw potato, birch pollen (ALK-Abello, Denmark), and natural rubber latex (NRL) (Stallergénes SPT reagent, France). Skin prick test to raw potato and birch pollen was positive in all the 9 patients but only 1 patient showed positive response to NRL reagent. SPT with purified potato allergen Sola t 1 was positive in 2/9 patients whereas SPT with Sola t 2-4 remained negative. Interestigly, potato RAST was positive (0.7-3.9 kU/L) in 5/9 and only 6 patients had increased total IgE levels (217-10772 kU/L). The present study with adult patients showed that clinical reactivity in handling of raw potatoes correlates well to positive SPT to raw potato and birch pollen. However, SPT results with purified heat-stabile food allergens of potato suggest that Sola t 1-4 do not play a major role in allergic reactions to raw potato. In conclusion, the heat-labile potato allergen(s), allegedly causing the clinical cross-reactivity for potato and birch pollen allergic patients, remain(s) to be identified.

↩

[8] - Seppälä U, Majamaa H, Turjanmaa K, Helin J, Reunala T, Kalkkinen N, et al. Identification of four novel potato (Solanum tuberosum) allergens belonging to the family of soybean trysin inhibitors. Allergy 2001;56:619-626

BACKGROUND: We have previously identified patatin (Sol t 1) of potato tubers as a major food allergen among atopic children. In addition to Sol t 1, concomitant IgE binding to other, then unidentified, potato proteins was observed. METHODS: Purification and identification of the putative allergens were done by both standard and advanced methods of protein chemistry. The patient series comprised 39 children with positive skin prick test (SPT) to raw potato. Immunoblotting and ELISA were used to examine IgE-binding ability and skin prick testing to assess in vivo reactivity of the purified potato proteins. RESULTS: Four IgE-binding potato proteins with molecular masses ranging from 16 to 20 kDa were purified and identified as cathepsin D-, cysteine-, and aspartic protease inhibitors belonging to the family of soybean trypsin inhibitors (Kunitz type). The proteins were designated Sol t 2, Sol t 3.0101, Sol t 3.0102, and Sol t 4. In ELISA, 51% of the sera of the 39 atopic children showed specific IgE to Sol t 2, 43% to Sol t 3.0101, 58% to Sol t 3.0102, and 67% to Sol t 4, respectively. All these four allergens were able to produce positive wheal-and-flare responses in SPT. CONCLUSION: In addition to Sol t 1, potato tubers contain several proteins belonging to the family of soybean trypsin inhibitors against which atopic children with positive SPT responses to raw potato have in vitro and in vivo reactive IgE antibodies.

↩

[9] - Majamaa H, Seppälä U, Palosuo T, Turjanmaa K, Kalkkinen N, Reunala T. Positive skin and oral challenge responses to potato and occurrence of IgE antibodies to patatin (Sol t 1) in infants with atopic dermatitis. Pediatr Allergy Immunol 2001;12:283-288

The clinical significance and molecular specificity of hypersensitivity reactions to raw and cooked potatoes remain ambiguous. We therefore investigated the clinical hypersensitivity to raw and cooked potato in infants suspected to have potato allergy and compared the findings with the occurrence of immunoglobulin E (IgE) antibodies to patatin (Sol t 1), characterized as the primary allergen of potato. Twelve infants (10 to 24 months of age) suffering from atopic dermatitis (AD) and suspected to have adverse reactions to potato, were examined. As a skin exposure test we used rubbing with both raw and cooked potato, and used open oral challenge with cooked potato for 7 days. A special eczema scoring system (SCORAD) was used to assess the severity of symptoms and signs of AD. Skin-prick tests (SPTs) were performed with raw potato and natural Sol t 1, and serological studies included measurement of total serum IgE and IgE antibodies to Sol t 1, and potato radioallergosorbent testing (RAST). The skin-rubbing test with raw potato was positive in seven (58%) and the oral challenge positive in eight (67%) infants. One infant presented with an immediate reaction and seven with a delayed reaction, i.e. exacerbation of AD, after oral challenge responses to cooked potato. Nine (75%) infants had IgE antibodies to Sol t 1 in enzyme-linked immunosorbent assay (ELISA), and SPT to natural Sol t 1 was positive in six (50%) potato-allergic infants. In conclusion, we observed positive challenge responses to both raw and cooked potato in food-allergic atopic infants. The presence of IgE antibodies and concomitant positive SPTs to the heat-stable potato allergen, Sol t 1, suggest that cooked potato can be an allergenic food for infants suffering from AD

↩

[10] - Dreborg S, Foucard T. Allergy to apple, carrot and potato in children with birch pollen allergy. Allergy 1983;38:167-172

Skin sensitivity to apple, carrot and potato, clinically related to birch pollinosis was investigated. Different skin test techniques using fresh fruit were compared. A simple prick test (SPT) technique with a lancet piercing the apple peel just before pricking the skin was shown to be the most practical and to give reproducible results. The allergenic activity in apple was found to be heat labile and deteriorated during storage at room temperature. Apple, carrot, potato, hazelnut and birch reactivity was transferable in Prausnitz-Kustner test like IgE antibodies. SPT reactivity to fresh material from apple, carrot and potato was investigated in 174 children of whom 128 suffered from pollen allergy. Positive SPT results were obtained almost exclusively in children who were SPT positive to a birch pollen extract. Children who noticed clinical symptoms when eating apple, raw carrot or potato were found to have a significantly larger SPT reaction than children with a negative history.

↩

[11] - Hannuksela M, Lahti A. Immediate reactions to fruits and vegetables. Contact Dermatitis 1977;3:79-84

Common fruits and vegetables were tested as such with the "scratch-chamber" method in 388 patients with various atopic disorders. Of the patients with hypersensitivity to birch pollen, 36% showed immediate positive responses to these natural, fresh materials. Apple, carrot, parsnip and potato elicited reactions more often than, e.g. swede, tomato, onion and parsley. On the basis of clinical data, the relevancy of the results of the skin tests was 80-90%. Both "false positive" and "false negative" responses were seen. Itching and tingling with or without oedema of the lips, mouth and tongue were the most common complaints after eating raw fruits and vegetables. In addition, laryngeal and abdominal disturbances, rhinitis and hand dermatitis were recorded. Among patients without allergy to birch pollen, reactions to fruits and vegetables were rare. The nature of the allergens could not be determined.

↩

[12] - Seppälä U, Palosuo T, Kalkkinen N, Seppälä U, Ylitalo L, Reunala T, et al. IgE reactivity to patatin-like allergen, Hev b 7, and to patatin of potato tuber, Sol t 1, in adults and children allergic to natural ruber latex. Allergy 2000;55:266-273

Patients allergic to natural rubber latex (NRL) frequently show positive skin prick tests (SPT) and hypersensitivity reactions to various fruits, such as avocado, banana, and kiwi, as well as to vegetables such as potato. METHODS: Hev b 7 was purified from NRL "C-serum" and Sol t 1 from potato extract, and they were detected by immunoblotting. IgE antibodies to Hev b 7 and Sol t 1 were measured with ELISA in sera from 35 adults and 35 children allergic to NRL. ELISA inhibition and immunoblotting were used to study allergen cross-reactivity. The in vivo reactivity of Hev b 7 and Sol t 1 were demonstrated in the SPT. RESULTS: Seventeen (49%) of the 35 NRL-allergic adults had IgE antibodies to Hev b 7, in contrast to only one of the 35 NRL-allergic children. Fifteen (43%) of the NRL-allergic adults and 29 (83%) of the NRL-allergic children had IgE antibodies to Sol t 1. Ten (29%) of the adult sera showed IgE binding to both Sol t 1 and Hev b 7, and crosswise inhibition tests with pooled sera revealed marked cross-reactivity. In the SPT, both natural Hev b 7 and Sol t 1 were able to produce a wheal and flare reaction. CONCLUSIONS: One-half of the NRL-allergic adults, but only one of the NRL-allergic children, had IgE antibodies to natural Hev b 7. These results suggest that Hev b 7 is an important NRL allergen for adults, but not for children. Elucidation of the clinical importance of the observed cross-reactivity between Hev b 7 and Sol t 1 requires further studies.

↩

[13] - Seppälä U, Majamaa H, Turjanmaa K, Vanto T, Kalkkinen N, Palosuo T, et al. Frequent skin prick test sensitivity to soy and potato in children: cross-reactivity to structurally related allergens? EAACI 21th Congress, Naples, 1-5 June, 2002, Poster n°217

Background: Frequency of allergic reactions to soy is growing. A number of soy proteins including Kunitz-type soybean trypsin inhibitor (KSTI) have been identified as allergens. Allergy to potato is also increasingly recognized, implying occurrence of IgE abntibodies to Sola t 2-4 members of the KSTI family. The purpose was to study the frequency of positive skin prick test (SPT) reactions to soy and potato in atopic children and examine whether the allergens can be cross-reactive. METHODS: 177 children (age <4 years) suspected for food allergy were prick tested with soybean and fresh potato. Sera from 17 children suspected for potato and 12 children for soy allergy were examined with ELISA for IgE antibodies to natural Sola t 2-4 and KSTI. Results: 10/177 (5%) children had positive SPT to soybean and 14 (7%) to potato. In ELISA, most (70%) potato SPT positive children showed IgE antibodies to KSTI and 75% had a positive soybean RAST. On the other hand, 9 (75%) children suspected for soy allergy had IgE antibodies to Sola t 2-4. A marked crosswise ELISA inhibition was evident for Sola t 2-4 and KSTI allergens. CONCLUSION: Children with suspected food allergy show frequently positive SPT to soybean and potato. Positive SPT and RAST to soybean may be due to cross-reactive IgE antibodies against structurally realted potato allergens, and vice versa. This cross-reactivity should be taken in account when examining children suspected for soy or potato allergy.

↩

[14] - Sowka S, Hafner C, Radauer C, Focke M, Brehler R, Astwood JD, et al. Molecular and immunologic characterization of new isoforms of the Hevea brasiliensis latex allergen Hev b 7: evidence of no cross-reactivity between Hev b 7 isoforms and potato patatin and proteins from avocado and banana. J Allergy Clin Immunol 1999;104:1302-1310

Hev b 7 is a Hevea brasiliensis latex allergen with sequence identities of 39% to 42% to patatins recently identified as potato allergens. The complementary DNAs encoding 2 different Hev b 7 isoforms were previously reported. OBJECTIVE: The aim of this study was to determine the sequence variation of Hev b 7 and to compare the IgE reactivity of individual isoforms in vitro and in vivo. A further objective was to evaluate possible cross-reactivities between Hev b 7 and patatins and proteins from banana and avocado. METHODS: An H brasiliensis lambda ZAP complementary DNA (cDNA) library was screened with use of a Hev b 7 cDNA probe. Four Hev b 7 isoforms were produced in recombinant form and their IgE-binding capacities were compared. IgE immunoblot inhibitions and ELISA inhibition assays were used to investigate the possible cross-reactivity between Hev b 7 and recombinant potato patatin and proteins from avocado and banana. RESULTS: Two new isoforms, S2 and D2, were identified by sequencing 32 cDNA clones with full-length coding regions. All 4 recombinant isoforms displayed esterase activity and identical IgE-binding capacities. The new isoforms S2 and D2 were evaluated in skin prick tests and provoked responses equivalent to natural Hev b 7. No cross-reactivity was observed between Hev b 7 isoforms and potato patatin and proteins from avocado and banana. CONCLUSIONS: All 4 recombinant Hev b 7 isoforms have equivalent IgE-binding capacity and therefore represent suitable reagents for the development of in vitro and in vivo diagnostic tests. Hev b 7, patatins, and their homologs appear not to contribute to cross-reactivity in the latex-fruit syndrome.

↩

[15] - Sowka S, Hafner C, Radauer C, Focke M, Brehler R, Astwood JD, et al. Molecular and immunologic characterization of new isoforms of the Hevea brasiliensis latex allergen Hev b 7: evidence of no cross-reactivity between Hev b 7 isoforms and potato patatin and proteins from avocado and banana. J Allergy Clin Immunol 1999;104:1302-1310

Hev b 7 is a Hevea brasiliensis latex allergen with sequence identities of 39% to 42% to patatins recently identified as potato allergens. The complementary DNAs encoding 2 different Hev b 7 isoforms were previously reported. OBJECTIVE: The aim of this study was to determine the sequence variation of Hev b 7 and to compare the IgE reactivity of individual isoforms in vitro and in vivo. A further objective was to evaluate possible cross-reactivities between Hev b 7 and patatins and proteins from banana and avocado. METHODS: An H brasiliensis lambda ZAP complementary DNA (cDNA) library was screened with use of a Hev b 7 cDNA probe. Four Hev b 7 isoforms were produced in recombinant form and their IgE-binding capacities were compared. IgE immunoblot inhibitions and ELISA inhibition assays were used to investigate the possible cross-reactivity between Hev b 7 and recombinant potato patatin and proteins from avocado and banana. RESULTS: Two new isoforms, S2 and D2, were identified by sequencing 32 cDNA clones with full-length coding regions. All 4 recombinant isoforms displayed esterase activity and identical IgE-binding capacities. The new isoforms S2 and D2 were evaluated in skin prick tests and provoked responses equivalent to natural Hev b 7. No cross-reactivity was observed between Hev b 7 isoforms and potato patatin and proteins from avocado and banana. CONCLUSIONS: All 4 recombinant Hev b 7 isoforms have equivalent IgE-binding capacity and therefore represent suitable reagents for the development of in vitro and in vivo diagnostic tests. Hev b 7, patatins, and their homologs appear not to contribute to cross-reactivity in the latex-fruit syndrome.

↩

[16] - Beausoleil JL, Spergel JM, Pawlowski NA. Anaphylaxis to raw potato. Ann Allergy Asthma Immunol 2001;86:68-70

BACKGROUND: Potato allergy has been described rarely, generally in relation to the Oral Allergy Syndrome (OAS). Adults with seasonal allergic rhinitis have been reported in whom peeling of raw potatoes causes oculonasal symptoms, wheezing, and contact urticaria. Skin testing with fresh fruits and vegetables has been recommended in cases of OAS, although the sensitivity of commercial potato extract is reportedly equal to that of fresh potato. CASE REPORT: This report describes a 4-year-old with raw potato-induced anaphylaxis. He rapidly developed urticaria, angioedema, respiratory distress, vomiting and diarrhea after biting into a raw potato that was being used for painting in preschool. Review of systems is significant for viral-induced wheezing, but no symptoms suggestive of seasonal allergic rhinitis were evident. His mother has a history of seasonal allergic rhinitis and contact urticaria with raw potato. Skin testing to commercial potato extract was negative and skin testing to fresh potato by the prick + prick method was markedly positive. Skin testing to birch tree was negative. An open challenge to a small amount of cooked potato was negative. Food challenge to raw potato was not considered indicated in this case of immediate anaphylaxis to a single food. CONCLUSIONS: This patient had clinical and skin test reactivity to raw and uncooked potato in the absence of OAS. The patient will be followed for the development of seasonal allergic rhinitis.

↩

[17] - Majamaa H, Seppälä U, Palosuo T, Turjanmaa K, Kalkkinen N, Reunala T. Positive skin and oral challenge responses to potato and occurrence of IgE antibodies to patatin (Sol t 1) in infants with atopic dermatitis. Pediatr Allergy Immunol 2001;12:283-288

The clinical significance and molecular specificity of hypersensitivity reactions to raw and cooked potatoes remain ambiguous. We therefore investigated the clinical hypersensitivity to raw and cooked potato in infants suspected to have potato allergy and compared the findings with the occurrence of immunoglobulin E (IgE) antibodies to patatin (Sol t 1), characterized as the primary allergen of potato. Twelve infants (10 to 24 months of age) suffering from atopic dermatitis (AD) and suspected to have adverse reactions to potato, were examined. As a skin exposure test we used rubbing with both raw and cooked potato, and used open oral challenge with cooked potato for 7 days. A special eczema scoring system (SCORAD) was used to assess the severity of symptoms and signs of AD. Skin-prick tests (SPTs) were performed with raw potato and natural Sol t 1, and serological studies included measurement of total serum IgE and IgE antibodies to Sol t 1, and potato radioallergosorbent testing (RAST). The skin-rubbing test with raw potato was positive in seven (58%) and the oral challenge positive in eight (67%) infants. One infant presented with an immediate reaction and seven with a delayed reaction, i.e. exacerbation of AD, after oral challenge responses to cooked potato. Nine (75%) infants had IgE antibodies to Sol t 1 in enzyme-linked immunosorbent assay (ELISA), and SPT to natural Sol t 1 was positive in six (50%) potato-allergic infants. In conclusion, we observed positive challenge responses to both raw and cooked potato in food-allergic atopic infants. The presence of IgE antibodies and concomitant positive SPTs to the heat-stable potato allergen, Sol t 1, suggest that cooked potato can be an allergenic food for infants suffering from AD

↩

[18] - de Swert LF, Cadot P, Ceuppens JL. Allergy to cooked white potatoes in infants and young children: A cause of severe, chronic allergic disease. J Allergy Clin Immunol 2002;110:524-529

BACKGROUND: Cases of allergy to cooked potato in children have been reported, some with immediate and others with late reactions. The clinical effects of chronic allergic reactions to potato and the effectiveness of diet on such reactions have not been described previously. OBJECTIVE: We sought to evaluate the importance of cooked potato as an allergenic food in individual cases of atopy in children. METHODS: Eight atopic children were selected on the basis of suspicion of allergy to cooked potatoes: all had potato-specific IgE, 2 of 8 had experienced immediate allergic reactions, and 6 of 8 had eczema that improved with a potato-elimination diet (decrease in severity scoring of atopic dermatis [SCORAD] index of >50%). The patients were evaluated by using skin prick tests with homemade cooked and noncooked potato extracts and with a commercial extract and by using IgE immunoblots from SDS-PAGE patterns of potato extract. Seven patients were challenged with cooked potato. The control group consisted of 9 age-matched atopic children, 8 of them with eczema. RESULTS: The mean SCORAD index decreased from 43.3 before to 11.5 after elimination of potato from the diet. Potato CAP values ranged from 3.71 to greater than 100 kUa/L. Potato challenge results were positive in 7 of 7 patients. Skin prick test responses were positive for cooked potato extracts in 7 of 7 patients, for noncooked extracts in 7 of 7 patients, and for the commercial extract in 8 of 8 patients compared with in 0 of 9, 1 of 9, and 1 of 9 subjects in the control group, respectively. During immunoblotting, 8 of 8 patient sera recognized one or more protein bands compared with 0 of 9 control subject sera. CONCLUSION: Allergy to cooked potatoes is a cause of severe allergic disease, with immediate reactions and eczema in some atopic infants and young children.

↩

[19] - Majamaa H, Seppälä U, Palosuo T, Turjanmaa K, Kalkkinen N, Reunala T. Positive skin and oral challenge responses to potato and occurrence of IgE antibodies to patatin (Sol t 1) in infants with atopic dermatitis. Pediatr Allergy Immunol 2001;12:283-288

The clinical significance and molecular specificity of hypersensitivity reactions to raw and cooked potatoes remain ambiguous. We therefore investigated the clinical hypersensitivity to raw and cooked potato in infants suspected to have potato allergy and compared the findings with the occurrence of immunoglobulin E (IgE) antibodies to patatin (Sol t 1), characterized as the primary allergen of potato. Twelve infants (10 to 24 months of age) suffering from atopic dermatitis (AD) and suspected to have adverse reactions to potato, were examined. As a skin exposure test we used rubbing with both raw and cooked potato, and used open oral challenge with cooked potato for 7 days. A special eczema scoring system (SCORAD) was used to assess the severity of symptoms and signs of AD. Skin-prick tests (SPTs) were performed with raw potato and natural Sol t 1, and serological studies included measurement of total serum IgE and IgE antibodies to Sol t 1, and potato radioallergosorbent testing (RAST). The skin-rubbing test with raw potato was positive in seven (58%) and the oral challenge positive in eight (67%) infants. One infant presented with an immediate reaction and seven with a delayed reaction, i.e. exacerbation of AD, after oral challenge responses to cooked potato. Nine (75%) infants had IgE antibodies to Sol t 1 in enzyme-linked immunosorbent assay (ELISA), and SPT to natural Sol t 1 was positive in six (50%) potato-allergic infants. In conclusion, we observed positive challenge responses to both raw and cooked potato in food-allergic atopic infants. The presence of IgE antibodies and concomitant positive SPTs to the heat-stable potato allergen, Sol t 1, suggest that cooked potato can be an allergenic food for infants suffering from AD

↩

[20] - Sánchez C, Chacón P, Pineda F. Potato allergy: changes by heat. EAACI 25th Congress, Vienna, 10-14 June, 2006, Poster n°518

Background:The potato allergy is uncommon in our area, although it is a basic food in Mediterranean diet. We present one case of potato allergy in which the application of different levels of heat change the allergic properties of the Major Protein Patatin (Solt t 1) Method:Male of 5 years old diagnosed of polialimentary allergy, with reaction of Atopic Dermatitis after eating some foods. In this case, potato allergy, he presented a general dermic reaction with OAS (oral allergy syndrome) and minimum difficulty for breathing with a cough, disnea and mouth edema after feeding during the first months of life. We do PRICK by PRICK with raw and cooked potato being positives both (10 and 12 mm). After we determined RAST to potato than resulted positive in 4th class. During a familiar lunch the patient ate, accidentally, fried potatoes and he didn‚t suffer anyone reaction. We tried to study what factor had influence in this tolerance, heat when frying or the importance of oil in decreasing absorption of protein Sol t 1. In the first place we analyzed the patient serum, determinating IgE antibody specifics against potato peel, potato pulp, boiled and fried potato (separated by sodium dodecacyl sulphat-polyacrylamide gel electrophoresis, SDS-PAGE). The binding of IgE antibody to allergens was analyzed by Western blot using serum from the allergic patient and a biotinilated mouse monoclonal antihuman IgE antibody, followed by streptavidin-horseradish peroxidase-labeled antimouse IgG antibody. Chemiluminiscence detection reagents were added following the manufacturer`s instructions. Results:In the inmunodetection made with potato peel we observed an identification of high and low Pm allergens (45 kDa-17kDa). After with potato pulp restricted all two bindings in 20.1 and 25 kDa. When we used heat during 30 min and with a temperature of 60°C we got denaturalized the allergens and we observed only two recognition at 30 and 21 kDa. Finally, if the heat is high (120 °C) and only during for 10 min we got the total elimination of potato allergens (4th band) Conclusion:We demonstrate how the use of heat can change the allergy potential of Major Protein of potato (Sol t 1) and high heat is more effective during a little time than low heat during more time, and moreover we eliminate the fact of the oil effect in this food.

↩

[21] - Hirschberg HJ, Simons JW, Dekker N, Egmond MR. Cloning, expression, purification and characterization of patatin, a novel phospholipase A. Eur J Biochem 2001;268:5037-5044

Patatin is the major protein constituent of potato tubers and displays broad esterase activity. The native enzyme actually belongs to a highly homologous multigene family of vacuolar glycoproteins. From these, the patB2 patatin gene was selected and cloned into pUC19 without its signal sequence but with an N-terminal histidine-tag. This patatin was overexpressed under the control of the lac promotor in Escherichia coli strain DH5alpha. The protein was recovered as inclusion bodies, folded into its native state by solubilization in urea and purified to homogeneity. Starting with one gram of inclusion bodies, 19 mg of pure and active recombinant patatin was isolated, with even higher specific activity than the glycosylated wild-type patatin purified from potato tubers. The purified enzyme showed esterolytic activity with p-nitrophenylesters dissolved in Triton X-100 micelles. The activity of patatin on p-nitrophenylesters with different carbon chain lengths showed an optimum for p-nitrophenylesters with 10 carbon atoms. Besides general esterolytic activity, the pure enzyme was found to display high phospholipase A activity in particular with the substrates 1,2-dioctanoyl-sn-glycero-3-phosphocholine (diC(8)PCho) (127 U.mg(-1)) and 1,2-dinonanoyl-sn-glycero-3-phosphocholine (diC(9)PCho) (109 U.mg(-1)). Recently, the structure of human cytosolic PLA(2) (cPLA(2)) was solved, showing a novel Ser-Asp active site dyad [1]. Based on a partial sequence alignment of patatin with human cPLA(2), we propose that patatin contains a similar active site dyad. To verify this assumption, conserved Ser, Asp and His residues in the family of patatins have been modified in patatin B2. Identification of active site residues was based on the observation of correctly folded but inactive variants. This led to the assignment of Ser54 and Asp192 as the active site serine and aspartate residues in patatin B2, respectively.

↩

[22] - Shewry PR. Tuber storage proteins. Ann Bot (Lond) 2003;91:755-769

A wide range of plants are grown for their edible tubers, but five species together account for almost 90 % of the total world production. These are potato (Solanum tuberosum), cassava (Manihot esculenta), sweet potato (Ipomoea batatus), yams (Dioscorea spp.) and taro (Colocasia, Cyrtosperma and Xanthosoma spp.). All of these, except cassava, contain groups of storage proteins, but these differ in the biological properties and evolutionary relationships. Thus, patatin from potato exhibits activity as an acylhydrolase and esterase, sporamin from sweet potato is an inhibitor of trypsin, and dioscorin from yam is a carbonic anhydrase. Both sporamin and dioscorin also exhibit antioxidant and radical scavenging activity. Taro differs from the other three crops in that it contains two major types of storage protein: a trypsin inhibitor related to sporamin and a mannose-binding lectin. These characteristics indicate that tuber storage proteins have evolved independently in different species, which contrasts with the highly conserved families of storage proteins present in seeds. Furthermore, all exhibit biological activities which could contribute to resistance to pests, pathogens or abiotic stresses, indicating that they may have dual roles in the tubers.

↩

[23] - Lee SK, Ye YM, Yoon SH, Lee BO, Kim SH, Park HS. Evaluation of the sensitization rates and identification of IgE-binding components in wild and genetically modified potatoes in patients with allergic disorders. Clin Mol Allergy 2006;4:10

ABSTRACT: BACKGROUND: The potato is one of the most common types of genetically modified (GM) food. However, there are no published data evaluating the impact of genetic manipulations on the allergenicity of GM potatoes. To compare the allergenicity of GM potatoes with that of wild-type potatoes using in vivo and in vitro methods in adult allergy patients sensitized to potatoes. METHODS: A total of 1886 patients with various allergic diseases and 38 healthy controls participated in the study. Skin-prick testing and IgE-ELISA were carried out with extracts prepared from wild-type and GM potatoes. An ELISA inhibition test was used to confirm the binding specificity. IgE-binding components in extracts from the two types of potato were identified by SDS-PAGE and IgE-immunoblotting. The effects of digestive enzymes and heat on the allergenicity of the extracts was evaluated by preincubating the potatoes with or without simulated gastric and intestinal fluids in the absence or presence of heat. RESULTS: Positive responses (ratio of the wheal size induced by the allergen to that induced by histamine (A/H) greater than or equal to 2+) to wild-type or GM potato extracts, as demonstrated by the skin-prick test, were observed in 108 patients (5.7%). Serum-specific IgE was detected in 0-88% of subjects who tested positively. ELISA inhibition tests indicated significant inhibition when extract from each type of potato was added. IgE-immunoblot analysis demonstrated the presence of 14 IgE-binding components within the wild-type potato and 9 within the GM potato, Furthermore, a common 45-kDa binding component that yielded similar IgE-binding patterns was noted in more than 80% of the reactions using sera from patients sensitized to wild-type or GM potato. Exposure to simulated gastric fluid and heat treatment similarly inhibited IgE binding by extracts from wild-type and GM potatoes, whereas minimal changes were obtained following exposure of the extracts to simulated intestinal fluid . CONCLUSION: Our results strongly suggest that genetic manipulation of potatoes does not increase their allergenic risk. The sensitization rate of adult allergy patients to both types of extract was 5.7%, and a common major allergen (45 kDa) was identified.

↩

[24] - Koppelman SJ, van Koningsveld GA, Knulst AC, Gruppen H, Pigmans IG, de Jongh HH. Effect of Heat-Induced Aggregation on the IgE Binding of Patatin (Sol t 1) Is Dominated by Other Potato Proteins. J Agric Food Chem 2002;50:1562-1568

The interaction of the major potato allergen patatin, Sol t 1, with IgE was investigated on a quantitative level as a function of heat treatment at different temperatures. On the basis of a number of publications, potato is considered to be a heat-labile allergen, but the molecular explanation for this behavior was not given. In this work, heat treatment of patatin in the absence and presence of other potato proteins mimicking the proteinaceous environment of the potato was studied. Using far-UV circular dichrosim spectroscopy, tryptophan fluorescence spectroscopy, and differential scanning calorimetry, the molecular transitions during heating of patatin were investigated. It was found that as long as patatin is not aggregated, denaturation of patatin on a secondary or tertiairy folding level is reversible with only a minor effect on the IgE affinity. Aggregation of patatin results in a nonreversible unfolding and a concomitant important decrease in affinity for IgE (25-fold). Aggregation of patatin in the presence of other potato proteins results in a less condensed aggregate compared to the situation of isolated patatin, resulting in a more pronounced decrease of affinity for IgE (110-fold). It is concluded that the heat lability of patatin-IgE interaction is explained by aggregation of patatin with other potato proteins rather than by denaturation of patatin itself.

↩

[25] - van Koningsveld GA, Gruppen H, de Jongh HH, Wijngaards G, van Boekel MA, Walstra P, et al. Effects of pH and heat treatments on the structure and solubility of potato proteins in different preparations. J Agric Food Chem 2001;49:4889-4897

The soluble potato proteins are mainly composed of patatin and protease inhibitors. Using DSC and both far-UV and near-UV CD spectroscopy, it was shown that potato proteins unfold between 55 and 75 degrees C. Increasing the ionic strength from 15 to 200 mM generally caused an increase in denaturation temperature. It was concluded that either the dimeric protein patatin unfolds in its monomeric state or its monomers are loosely associated and unfold independently. Thermal unfolding of the protease inhibitors was correlated with a decrease in protease inhibitor activities and resulted in an ionic strength dependent loss of protein solubility. Potato proteins were soluble at neutral and strongly acidic pH values. The tertiary structure of patatin was irreversibly altered by precipitation at pH 5. At mildly acidic pH the overall potato protein solubility was dependent on ionic strength and the presence of unfolded patatin.

↩

[26] - Arif SAM, Hamilton RG, Yusof F, Chew NP, Loke YH, Nimkar S, et al. Isolation and characterization of the Early Nodule Specific Protein homologue (Hev b 13), an allergenic lipolytic esterase from Hevea brasiliensis latex. J Biol Chem 2004;279:23933-23941

Recurring reports of a highly allergenic 42-46-kDa protein in Hevea brasiliensis latex appeared to have been resolved with the discovery of a 43-kDa allergenic latex protein that was a homologue to patatin. However, the low to moderate prevalence of sensitization to the protein, designated Hev b 7, among latex-allergic patients could not adequately explain the frequent observations of the 42-46-kDa allergen. This led to the hypothesis that another, more allergenic protein of a similar molecular mass existed in Hevea latex. We report the isolation and purification of a 42.98-kDa latex glycoprotein showing homology to the early nodule-specific protein (ENSP) of the legumes Medicago sativa, Medicago truncatula, and Glycine max. The protein is allergenic, being recognized by immunoglobulin E (IgE) in sera from latex-allergic patients. The IgE epitope resides on the carbohydrate moiety of the protein, and the presence of a similar carbohydrate component on potato tuber patatin enables the latter to inhibit IgE binding to the ENSP homologue. The cDNA encoding the ENSP homologue was isolated by reverse transcription-PCR and cloned. The protein predicted from the cDNA sequence has 391 amino acids, the first 26 of which constitute a putative signal peptide. The deduced molecular mass of the mature protein is 40.40 kDa, while its isoelectric point is estimated at 5.0. The discrepancy between the predicted and observed molecular mass might be due to glycosylation, for which three N-sites on the protein are predicted. The purified protein showed lipase and esterase activities and may be involved in plant defense.

↩

[27] - Seppälä U, Palosuo T, Kalkkinen N, Seppälä U, Ylitalo L, Reunala T, et al. IgE reactivity to patatin-like allergen, Hev b 7, and to patatin of potato tuber, Sol t 1, in adults and children allergic to natural ruber latex. Allergy 2000;55:266-273

Patients allergic to natural rubber latex (NRL) frequently show positive skin prick tests (SPT) and hypersensitivity reactions to various fruits, such as avocado, banana, and kiwi, as well as to vegetables such as potato. METHODS: Hev b 7 was purified from NRL "C-serum" and Sol t 1 from potato extract, and they were detected by immunoblotting. IgE antibodies to Hev b 7 and Sol t 1 were measured with ELISA in sera from 35 adults and 35 children allergic to NRL. ELISA inhibition and immunoblotting were used to study allergen cross-reactivity. The in vivo reactivity of Hev b 7 and Sol t 1 were demonstrated in the SPT. RESULTS: Seventeen (49%) of the 35 NRL-allergic adults had IgE antibodies to Hev b 7, in contrast to only one of the 35 NRL-allergic children. Fifteen (43%) of the NRL-allergic adults and 29 (83%) of the NRL-allergic children had IgE antibodies to Sol t 1. Ten (29%) of the adult sera showed IgE binding to both Sol t 1 and Hev b 7, and crosswise inhibition tests with pooled sera revealed marked cross-reactivity. In the SPT, both natural Hev b 7 and Sol t 1 were able to produce a wheal and flare reaction. CONCLUSIONS: One-half of the NRL-allergic adults, but only one of the NRL-allergic children, had IgE antibodies to natural Hev b 7. These results suggest that Hev b 7 is an important NRL allergen for adults, but not for children. Elucidation of the clinical importance of the observed cross-reactivity between Hev b 7 and Sol t 1 requires further studies.

↩

[28] - Majamaa H, Seppälä U, Palosuo T, Turjanmaa K, Kalkkinen N, Reunala T. Positive skin and oral challenge responses to potato and occurrence of IgE antibodies to patatin (Sol t 1) in infants with atopic dermatitis. Pediatr Allergy Immunol 2001;12:283-288

The clinical significance and molecular specificity of hypersensitivity reactions to raw and cooked potatoes remain ambiguous. We therefore investigated the clinical hypersensitivity to raw and cooked potato in infants suspected to have potato allergy and compared the findings with the occurrence of immunoglobulin E (IgE) antibodies to patatin (Sol t 1), characterized as the primary allergen of potato. Twelve infants (10 to 24 months of age) suffering from atopic dermatitis (AD) and suspected to have adverse reactions to potato, were examined. As a skin exposure test we used rubbing with both raw and cooked potato, and used open oral challenge with cooked potato for 7 days. A special eczema scoring system (SCORAD) was used to assess the severity of symptoms and signs of AD. Skin-prick tests (SPTs) were performed with raw potato and natural Sol t 1, and serological studies included measurement of total serum IgE and IgE antibodies to Sol t 1, and potato radioallergosorbent testing (RAST). The skin-rubbing test with raw potato was positive in seven (58%) and the oral challenge positive in eight (67%) infants. One infant presented with an immediate reaction and seven with a delayed reaction, i.e. exacerbation of AD, after oral challenge responses to cooked potato. Nine (75%) infants had IgE antibodies to Sol t 1 in enzyme-linked immunosorbent assay (ELISA), and SPT to natural Sol t 1 was positive in six (50%) potato-allergic infants. In conclusion, we observed positive challenge responses to both raw and cooked potato in food-allergic atopic infants. The presence of IgE antibodies and concomitant positive SPTs to the heat-stable potato allergen, Sol t 1, suggest that cooked potato can be an allergenic food for infants suffering from AD

↩

[29] - Seppälä U, Alenius H, Turjanmaa K, Reunala T, Palosuo T, Kalkkinen N. Identification of patatin as a novel allergen for children with positive skin prick test responses to raw potato. J Allergy Clin Immunol 1999;103:165-171

BACKGROUND: Peeling of raw potatoes may cause allergic symptoms, such as sneezing, wheezing, and contact urticaria, for adults. For children, potatoes as food may cause various allergic reactions. However, the identity and molecular structure of the putative allergens in potato have remained unknown. OBJECTIVE: The aim of our study was to identify possible major allergens in potato by using sera of atopic children suspected of having food allergy and having positive skin prick test responses to raw potato. METHODS: Potato proteins were purified by standard methods of protein chemistry and characterized with amino-terminal sequencing and mass spectrometry. The IgE-binding ability of the purified proteins was verified by immunoblotting and ELISA with IgE antibodies from the sera of atopic children having positive skin prick test responses to raw potato. RESULTS: Immunoblotting showed strong IgE binding to a 43-kd protein, identified as patatin, the main storage protein of potato tubers. In ELISA, 20 of 27 (74%) children with positive skin prick test responses to potato and none of the control subjects showed specific binding of IgE antibodies to purified patatin. A positive wheal-and-flare reaction was seen in 8 of 14 children prick tested with purified patatin. CONCLUSION: These results show that patatin in potatoes is a significant, previously unrecognized,IgE-binding protein for children with a positive skin prick test response to raw potato. Further studies are needed to confirm the clinical importance of potatoes, and especially patatin, as a food allergen.

↩

[30] - Seppälä U, Majamaa H, Turjanmaa K, Helin J, Reunala T, Kalkkinen N, et al. Identification of four novel potato (Solanum tuberosum) allergens belonging to the family of soybean trysin inhibitors. Allergy 2001;56:619-626

BACKGROUND: We have previously identified patatin (Sol t 1) of potato tubers as a major food allergen among atopic children. In addition to Sol t 1, concomitant IgE binding to other, then unidentified, potato proteins was observed. METHODS: Purification and identification of the putative allergens were done by both standard and advanced methods of protein chemistry. The patient series comprised 39 children with positive skin prick test (SPT) to raw potato. Immunoblotting and ELISA were used to examine IgE-binding ability and skin prick testing to assess in vivo reactivity of the purified potato proteins. RESULTS: Four IgE-binding potato proteins with molecular masses ranging from 16 to 20 kDa were purified and identified as cathepsin D-, cysteine-, and aspartic protease inhibitors belonging to the family of soybean trypsin inhibitors (Kunitz type). The proteins were designated Sol t 2, Sol t 3.0101, Sol t 3.0102, and Sol t 4. In ELISA, 51% of the sera of the 39 atopic children showed specific IgE to Sol t 2, 43% to Sol t 3.0101, 58% to Sol t 3.0102, and 67% to Sol t 4, respectively. All these four allergens were able to produce positive wheal-and-flare responses in SPT. CONCLUSION: In addition to Sol t 1, potato tubers contain several proteins belonging to the family of soybean trypsin inhibitors against which atopic children with positive SPT responses to raw potato have in vitro and in vivo reactive IgE antibodies.

↩

[31] - Majamaa H, Seppälä U, Palosuo T, Reunala T, Kalkkinen N, Turjanmaa K. Hypersensitivity to Raw Potatoes in Adults. AAAAI 58th Annual Meeting, New York, 1-6 March, 2002, Poster n°659

Previous studies have shown that hypersensitivity reaction between raw and cooked potatoes (Solanum tuberosum) are substantially different. Young infants and children suffering from food allergies may develop allergy to cooked potatoes showing specific IgE to heat-stabile potato allergens, Sola t 1-4. In general, however, hypersensitivity reactions to raw potatoes are associated with atopic adults frequently showing positive skin prick test (SPT) to birch (Betula verrucosa) pollen. Immunological basis for this phenomenon has considered to result from IgE-mediated cross-reactivity between heat-labile pollen and potato allergens. Allergic reactions to raw potatoes are usually immediate, appearing within minutes after peeling and/or handling of them. The clinical spectrum includes symptoms ranging from contact urticaria and itching of hands to non-cutaneous symptoms such as rhinitis and wheezing. In the present study 9 adults (ranging from 15 to 46 years) showing clinical history of hypersensitivity against raw potatoes were examined. Total and potato specific IgE was measured by RAST (Pharmacia, Sweden) and all the patients were SPT with purified potato allergens, Sola t 1-4, raw potato, birch pollen (ALK-Abello, Denmark), and natural rubber latex (NRL) (Stallergénes SPT reagent, France). Skin prick test to raw potato and birch pollen was positive in all the 9 patients but only 1 patient showed positive response to NRL reagent. SPT with purified potato allergen Sola t 1 was positive in 2/9 patients whereas SPT with Sola t 2-4 remained negative. Interestigly, potato RAST was positive (0.7-3.9 kU/L) in 5/9 and only 6 patients had increased total IgE levels (217-10772 kU/L). The present study with adult patients showed that clinical reactivity in handling of raw potatoes correlates well to positive SPT to raw potato and birch pollen. However, SPT results with purified heat-stabile food allergens of potato suggest that Sola t 1-4 do not play a major role in allergic reactions to raw potato. In conclusion, the heat-labile potato allergen(s), allegedly causing the clinical cross-reactivity for potato and birch pollen allergic patients, remain(s) to be identified.

↩

[32] - Sowka S, Hafner C, Radauer C, Focke M, Brehler R, Astwood JD, et al. Molecular and immunologic characterization of new isoforms of the Hevea brasiliensis latex allergen Hev b 7: evidence of no cross-reactivity between Hev b 7 isoforms and potato patatin and proteins from avocado and banana. J Allergy Clin Immunol 1999;104:1302-1310

Hev b 7 is a Hevea brasiliensis latex allergen with sequence identities of 39% to 42% to patatins recently identified as potato allergens. The complementary DNAs encoding 2 different Hev b 7 isoforms were previously reported. OBJECTIVE: The aim of this study was to determine the sequence variation of Hev b 7 and to compare the IgE reactivity of individual isoforms in vitro and in vivo. A further objective was to evaluate possible cross-reactivities between Hev b 7 and patatins and proteins from banana and avocado. METHODS: An H brasiliensis lambda ZAP complementary DNA (cDNA) library was screened with use of a Hev b 7 cDNA probe. Four Hev b 7 isoforms were produced in recombinant form and their IgE-binding capacities were compared. IgE immunoblot inhibitions and ELISA inhibition assays were used to investigate the possible cross-reactivity between Hev b 7 and recombinant potato patatin and proteins from avocado and banana. RESULTS: Two new isoforms, S2 and D2, were identified by sequencing 32 cDNA clones with full-length coding regions. All 4 recombinant isoforms displayed esterase activity and identical IgE-binding capacities. The new isoforms S2 and D2 were evaluated in skin prick tests and provoked responses equivalent to natural Hev b 7. No cross-reactivity was observed between Hev b 7 isoforms and potato patatin and proteins from avocado and banana. CONCLUSIONS: All 4 recombinant Hev b 7 isoforms have equivalent IgE-binding capacity and therefore represent suitable reagents for the development of in vitro and in vivo diagnostic tests. Hev b 7, patatins, and their homologs appear not to contribute to cross-reactivity in the latex-fruit syndrome.

↩

[33] - Seppälä U, Palosuo T, Kalkkinen N, Seppälä U, Ylitalo L, Reunala T, et al. IgE reactivity to patatin-like allergen, Hev b 7, and to patatin of potato tuber, Sol t 1, in adults and children allergic to natural ruber latex. Allergy 2000;55:266-273

Patients allergic to natural rubber latex (NRL) frequently show positive skin prick tests (SPT) and hypersensitivity reactions to various fruits, such as avocado, banana, and kiwi, as well as to vegetables such as potato. METHODS: Hev b 7 was purified from NRL "C-serum" and Sol t 1 from potato extract, and they were detected by immunoblotting. IgE antibodies to Hev b 7 and Sol t 1 were measured with ELISA in sera from 35 adults and 35 children allergic to NRL. ELISA inhibition and immunoblotting were used to study allergen cross-reactivity. The in vivo reactivity of Hev b 7 and Sol t 1 were demonstrated in the SPT. RESULTS: Seventeen (49%) of the 35 NRL-allergic adults had IgE antibodies to Hev b 7, in contrast to only one of the 35 NRL-allergic children. Fifteen (43%) of the NRL-allergic adults and 29 (83%) of the NRL-allergic children had IgE antibodies to Sol t 1. Ten (29%) of the adult sera showed IgE binding to both Sol t 1 and Hev b 7, and crosswise inhibition tests with pooled sera revealed marked cross-reactivity. In the SPT, both natural Hev b 7 and Sol t 1 were able to produce a wheal and flare reaction. CONCLUSIONS: One-half of the NRL-allergic adults, but only one of the NRL-allergic children, had IgE antibodies to natural Hev b 7. These results suggest that Hev b 7 is an important NRL allergen for adults, but not for children. Elucidation of the clinical importance of the observed cross-reactivity between Hev b 7 and Sol t 1 requires further studies.

↩

[34] - Seppälä U, Majamaa H, Turjanmaa K, Helin J, Reunala T, Kalkkinen N, et al. Identification of four novel potato (Solanum tuberosum) allergens belonging to the family of soybean trysin inhibitors. Allergy 2001;56:619-626

BACKGROUND: We have previously identified patatin (Sol t 1) of potato tubers as a major food allergen among atopic children. In addition to Sol t 1, concomitant IgE binding to other, then unidentified, potato proteins was observed. METHODS: Purification and identification of the putative allergens were done by both standard and advanced methods of protein chemistry. The patient series comprised 39 children with positive skin prick test (SPT) to raw potato. Immunoblotting and ELISA were used to examine IgE-binding ability and skin prick testing to assess in vivo reactivity of the purified potato proteins. RESULTS: Four IgE-binding potato proteins with molecular masses ranging from 16 to 20 kDa were purified and identified as cathepsin D-, cysteine-, and aspartic protease inhibitors belonging to the family of soybean trypsin inhibitors (Kunitz type). The proteins were designated Sol t 2, Sol t 3.0101, Sol t 3.0102, and Sol t 4. In ELISA, 51% of the sera of the 39 atopic children showed specific IgE to Sol t 2, 43% to Sol t 3.0101, 58% to Sol t 3.0102, and 67% to Sol t 4, respectively. All these four allergens were able to produce positive wheal-and-flare responses in SPT. CONCLUSION: In addition to Sol t 1, potato tubers contain several proteins belonging to the family of soybean trypsin inhibitors against which atopic children with positive SPT responses to raw potato have in vitro and in vivo reactive IgE antibodies.

↩

[35] - Seppälä U, Majamaa H, Turjanmaa K, Helin J, Reunala T, Kalkkinen N, et al. Identification of four novel potato (Solanum tuberosum) allergens belonging to the family of soybean trysin inhibitors. Allergy 2001;56:619-626

BACKGROUND: We have previously identified patatin (Sol t 1) of potato tubers as a major food allergen among atopic children. In addition to Sol t 1, concomitant IgE binding to other, then unidentified, potato proteins was observed. METHODS: Purification and identification of the putative allergens were done by both standard and advanced methods of protein chemistry. The patient series comprised 39 children with positive skin prick test (SPT) to raw potato. Immunoblotting and ELISA were used to examine IgE-binding ability and skin prick testing to assess in vivo reactivity of the purified potato proteins. RESULTS: Four IgE-binding potato proteins with molecular masses ranging from 16 to 20 kDa were purified and identified as cathepsin D-, cysteine-, and aspartic protease inhibitors belonging to the family of soybean trypsin inhibitors (Kunitz type). The proteins were designated Sol t 2, Sol t 3.0101, Sol t 3.0102, and Sol t 4. In ELISA, 51% of the sera of the 39 atopic children showed specific IgE to Sol t 2, 43% to Sol t 3.0101, 58% to Sol t 3.0102, and 67% to Sol t 4, respectively. All these four allergens were able to produce positive wheal-and-flare responses in SPT. CONCLUSION: In addition to Sol t 1, potato tubers contain several proteins belonging to the family of soybean trypsin inhibitors against which atopic children with positive SPT responses to raw potato have in vitro and in vivo reactive IgE antibodies.

↩

[36] - Seppälä U, Majamaa H, Turjanmaa K, Helin J, Reunala T, Kalkkinen N, et al. Identification of four novel potato (Solanum tuberosum) allergens belonging to the family of soybean trysin inhibitors. Allergy 2001;56:619-626

BACKGROUND: We have previously identified patatin (Sol t 1) of potato tubers as a major food allergen among atopic children. In addition to Sol t 1, concomitant IgE binding to other, then unidentified, potato proteins was observed. METHODS: Purification and identification of the putative allergens were done by both standard and advanced methods of protein chemistry. The patient series comprised 39 children with positive skin prick test (SPT) to raw potato. Immunoblotting and ELISA were used to examine IgE-binding ability and skin prick testing to assess in vivo reactivity of the purified potato proteins. RESULTS: Four IgE-binding potato proteins with molecular masses ranging from 16 to 20 kDa were purified and identified as cathepsin D-, cysteine-, and aspartic protease inhibitors belonging to the family of soybean trypsin inhibitors (Kunitz type). The proteins were designated Sol t 2, Sol t 3.0101, Sol t 3.0102, and Sol t 4. In ELISA, 51% of the sera of the 39 atopic children showed specific IgE to Sol t 2, 43% to Sol t 3.0101, 58% to Sol t 3.0102, and 67% to Sol t 4, respectively. All these four allergens were able to produce positive wheal-and-flare responses in SPT. CONCLUSION: In addition to Sol t 1, potato tubers contain several proteins belonging to the family of soybean trypsin inhibitors against which atopic children with positive SPT responses to raw potato have in vitro and in vivo reactive IgE antibodies.

↩

[37] - Lee SK, Ye YM, Yoon SH, Lee BO, Kim SH, Park HS. Evaluation of the sensitization rates and identification of IgE-binding components in wild and genetically modified potatoes in patients with allergic disorders. Clin Mol Allergy 2006;4:10

ABSTRACT: BACKGROUND: The potato is one of the most common types of genetically modified (GM) food. However, there are no published data evaluating the impact of genetic manipulations on the allergenicity of GM potatoes. To compare the allergenicity of GM potatoes with that of wild-type potatoes using in vivo and in vitro methods in adult allergy patients sensitized to potatoes. METHODS: A total of 1886 patients with various allergic diseases and 38 healthy controls participated in the study. Skin-prick testing and IgE-ELISA were carried out with extracts prepared from wild-type and GM potatoes. An ELISA inhibition test was used to confirm the binding specificity. IgE-binding components in extracts from the two types of potato were identified by SDS-PAGE and IgE-immunoblotting. The effects of digestive enzymes and heat on the allergenicity of the extracts was evaluated by preincubating the potatoes with or without simulated gastric and intestinal fluids in the absence or presence of heat. RESULTS: Positive responses (ratio of the wheal size induced by the allergen to that induced by histamine (A/H) greater than or equal to 2+) to wild-type or GM potato extracts, as demonstrated by the skin-prick test, were observed in 108 patients (5.7%). Serum-specific IgE was detected in 0-88% of subjects who tested positively. ELISA inhibition tests indicated significant inhibition when extract from each type of potato was added. IgE-immunoblot analysis demonstrated the presence of 14 IgE-binding components within the wild-type potato and 9 within the GM potato, Furthermore, a common 45-kDa binding component that yielded similar IgE-binding patterns was noted in more than 80% of the reactions using sera from patients sensitized to wild-type or GM potato. Exposure to simulated gastric fluid and heat treatment similarly inhibited IgE binding by extracts from wild-type and GM potatoes, whereas minimal changes were obtained following exposure of the extracts to simulated intestinal fluid . CONCLUSION: Our results strongly suggest that genetic manipulation of potatoes does not increase their allergenic risk. The sensitization rate of adult allergy patients to both types of extract was 5.7%, and a common major allergen (45 kDa) was identified.

↩

[38] - Hoffmann-Sommergruber K, Vanek-Krebitz M, Radauer C, Wen J, Ferreira F, Scheiner O, et al. Genomic characterization of members of the Bet v1 family: genes coding for allergens and PR-proteins share intron positions. Gene 1997;197:91-100

Bet v 1, the major birch pollen allergen, is a member of a multigene family; a number of isoforms and homologous proteins from closely related species (alder, hazel and hornbeam) has been isolated and their cDNAs cloned and characterized. Genomic clones coding for Bet v 1 and homologues from apple and hazel were isolated and sequenced. Some of these clones contained intervening sequences. The exon-intron formation is highly conserved throughout this family of pathogenesis-related proteins in dicot plants and is also found in Aopr1 (Asparagus officinalis), a monocol species. Phylogenetic analysis suggested a possible common origin of the intron position in these homologous proteins at codon 62 in various families of flowering plants, including Fagaceae, Rosaceae and Apiaceae. This conserved 'proto-splice site' may point to a structure/function relationship. A conserved sequence motif (P-loop) was also found in all members of this protein family. Moreover, there is a certain degree of sequence similarity among the proteins derived from various species throughout the dicots and the only monocot examined. This fact is reflected by cross-reactivity from monoclonal and polyclonal antibodies raised against Bet v 1.

↩

[39] - Ebner C, Hirschwehr R, Bauer L, Breiteneder H, Valenta R, Ebner H, et al. Identification of allergens in fruits and vegetables: IgE cross-reactivities with the important birch pollen allergens Bet v 1 and Bet v 2 (birch profilin). J Allergy Clin Immunol 1995;95:962-969

In this study serum samples collected from 20 patients with birch pollen allergy were investigated. All patients had experienced allergic symptoms after contact with or ingestion of particular fresh fruits and vegetables known as birch pollen-related foods. METHODS: Serum samples were tested by means of immunoblotting for IgE reactivities with proteins in extracts of birch pollen, apple, pear, celery, carrot, and potato. Anti-Bet v 1 and anti-Bet v 2 antibodies were used to investigate cross-reactivity. Inhibition studies were performed by preincubation of sera with recombinant Bet v 1 and Bet v 2. RESULTS: IgE binding to proteins, corresponding to the major birch pollen allergen Bet v 1 and to Bet v 2 (birch pollen profilin) could be observed. An allergen homologous to Bet v 1 could be detected in apple, pear, and celery when a Bet v 1-specific monoclonal antibody was used. Testing a polyclonal rabbit anti-Bet v 2 antibody with extracts of the respective plants revealed the presence of profilins in every source tested. Inhibition with recombinant Bet v 1 and Bet v 2 led to complete blocking or marked reduction of IgE binding to proteins of comparable molecular weights in the respective food extracts, indicating IgE cross-reactivity. CONCLUSION: Our results indicate that many plant-derived food agents contain proteins with high homology to the birch pollen allergens Bet v 1 and Bet v 2 and must therefore be considered as potentially threatening for patients with tree pollen allergy.

↩

[40] - Ebner C, Hirschwehr R, Bauer L, Breiteneder H, Valenta R, Hoffmann K, et al. Identification of allergens in apple, pear, celery, carrot and potato: cross-reactivity with pollen allergens. Monogr Allergy 1996;32:73-77

↩

[41] - Palomares O, Villalba M, Quiralte J, Polo F, Rodriguez R. 1,3-beta-glucanases as candidates in latex-pollen-vegetable food cross-reactivity. Clin Exp Allergy 2005;35:345-351

Summary Background 1,3-beta-glucanases (group 2 of pathogenesis-related proteins) are enzymes widely distributed among higher plants and have been recently proven to be significant allergens. Objective The aim of this work was to study the potential implication of 1,3-beta-glucanases in cross-reactivities among latex, pollen and vegetable foods. Methods The cDNA encoding the N-terminal domain (NtD) of Ole e 9, a major allergenic 1,3-beta-glucanase from olive pollen, was amplified by polymerase chain reaction and produced as a recombinant protein in Pichia pastoris (recombinant N-terminal domain, rNtD). Circular dichroism, ELISA, immunoblotting and immunoblotting inhibition experiments were carried out. Sera from olive pollen allergic patients and a rNtD-specific polyclonal antiserum were used. Results The NtD of Ole e 9 has been produced at high yield in the yeast P. pastoris and possesses 1,3-beta-glucanase activity. The expressed polypeptide conserves IgE and IgG immunodominant epitopes of the whole Ole e 9. A rNtD-specific polyclonal antiserum and sera from olive pollen allergic patients allowed detection of IgG and IgE reactive peptidic epitopes common to 1,3-beta-glucanase Ole e 9 in extracts from ash and birch pollen, tomato, potato, bell-pepper, banana and latex. Conclusion rNtD and homologous glucanases are new molecules to be used in diagnostic protocols as they could help to identify allergic pollen patients who are at risk for developing allergic symptoms to fruits, vegetables and latex.

↩

[42] - Asero R, Mistrello G, Roncarolo D, Amato S. Detection of Some Safe Plant-Derived Foods for LTP-Allergic Patients. Int Arch Allergy Immunol 2007;144:57-63

BACKGROUND: Lipid transfer protein (LTP) is a widely cross-reacting plant pan-allergen. Adverse reactions to Rosaceae, tree nuts, peanut, beer, maize, mustard, asparagus, grapes, mulberry, cabbage, dates, orange, fig, kiwi, lupine, fennel, celery, tomato, eggplant, lettuce, chestnut and pineapple have been recorded . OBJECTIVE: To detect vegetable foods to be regarded as safe for LTP-allergic patients . METHODS: Tolerance/intolerance to a large spectrum of vegetable foods other than Rosaceae, tree nuts and peanut was assessed by interview in 49 subjects monosensitized to LTP and in three distinct groups of controls monosensitized to Bet v 1 (n = 24) or Bet v 2 (n = 18), or sensitized to both LTP and birch pollen (n = 16), all with a history of vegetable food allergy. Patients and controls underwent skin prick test (SPT) with a large spectrum of vegetable foods. The absence of IgE reactivity to foods that were negative in both clinical history and SPT was confirmed by immunoblot analysis and their clinical tolerance was finally assessed by open oral challenge (50 g per food) . RESULTS: All patients reported tolerance and showed negative SPT to carrot, potato, banana and melon; these foods scored positive in SPT and elicited clinical symptoms in a significant proportion of patients from all three control groups. All patients tolerated these four foods on oral challenge. Immunoblot analysis confirmed the lack of IgE reactivity to these foods by LTP-allergic patients . CONCLUSION: Carrot, potato, banana and melon seem safe for LTP-allergic patients. This finding may be helpful for a better management of allergy to LTP.

↩

[43] - Schubert S, Steinhart H, Paschke A. The Influence of Different Potato (Solanum tuberosum) Strains and Technological Processing on Allergenicity. Food Agric Immunol 2003;15:41-53

This study was undertaken to investigate the distinctions between different horticultural strains of potato and the influence of technological treatment on allergenicity. The allergenic potencies of raw and processed fruit extracts were determined by means of electrophoretical and immunological methods. For immunological assays sera of 12 patients with a sensibilization to raw potato (EAST-classes 2) were pooled. The examinations of extracts from six different potato strains showed differences in the pattern of the IgE-binding proteins, but no distinctions could be observed in the allergenic potency by EAST-inhibition experiments. The technological influence on allergenicity was investigated on a model-production of potato-flakes and different heating processes. The data show only a slight decrease of allergenic activity by raising the temperature. In spite of this it proved possible to determine a new protein band in SDS-PAGE with molecular weight of approximately 50 kDa in extracts resulting from heated potatoes, which also showed an IgE binding activity. The application of additives had no influence on allergenic potency.

↩

[44] - Majamaa H, Seppälä U, Palosuo T, Reunala T, Kalkkinen N, Turjanmaa K. Hypersensitivity to Raw Potatoes in Adults. AAAAI 58th Annual Meeting, New York, 1-6 March, 2002, Poster n°659

Previous studies have shown that hypersensitivity reaction between raw and cooked potatoes (Solanum tuberosum) are substantially different. Young infants and children suffering from food allergies may develop allergy to cooked potatoes showing specific IgE to heat-stabile potato allergens, Sola t 1-4. In general, however, hypersensitivity reactions to raw potatoes are associated with atopic adults frequently showing positive skin prick test (SPT) to birch (Betula verrucosa) pollen. Immunological basis for this phenomenon has considered to result from IgE-mediated cross-reactivity between heat-labile pollen and potato allergens. Allergic reactions to raw potatoes are usually immediate, appearing within minutes after peeling and/or handling of them. The clinical spectrum includes symptoms ranging from contact urticaria and itching of hands to non-cutaneous symptoms such as rhinitis and wheezing. In the present study 9 adults (ranging from 15 to 46 years) showing clinical history of hypersensitivity against raw potatoes were examined. Total and potato specific IgE was measured by RAST (Pharmacia, Sweden) and all the patients were SPT with purified potato allergens, Sola t 1-4, raw potato, birch pollen (ALK-Abello, Denmark), and natural rubber latex (NRL) (Stallergénes SPT reagent, France). Skin prick test to raw potato and birch pollen was positive in all the 9 patients but only 1 patient showed positive response to NRL reagent. SPT with purified potato allergen Sola t 1 was positive in 2/9 patients whereas SPT with Sola t 2-4 remained negative. Interestigly, potato RAST was positive (0.7-3.9 kU/L) in 5/9 and only 6 patients had increased total IgE levels (217-10772 kU/L). The present study with adult patients showed that clinical reactivity in handling of raw potatoes correlates well to positive SPT to raw potato and birch pollen. However, SPT results with purified heat-stabile food allergens of potato suggest that Sola t 1-4 do not play a major role in allergic reactions to raw potato. In conclusion, the heat-labile potato allergen(s), allegedly causing the clinical cross-reactivity for potato and birch pollen allergic patients, remain(s) to be identified.

↩

[45] - Majamaa H, Seppälä U, Palosuo T, Turjanmaa K, Kalkkinen N, Reunala T. Positive skin and oral challenge responses to potato and occurrence of IgE antibodies to patatin (Sol t 1) in infants with atopic dermatitis. Pediatr Allergy Immunol 2001;12:283-288

The clinical significance and molecular specificity of hypersensitivity reactions to raw and cooked potatoes remain ambiguous. We therefore investigated the clinical hypersensitivity to raw and cooked potato in infants suspected to have potato allergy and compared the findings with the occurrence of immunoglobulin E (IgE) antibodies to patatin (Sol t 1), characterized as the primary allergen of potato. Twelve infants (10 to 24 months of age) suffering from atopic dermatitis (AD) and suspected to have adverse reactions to potato, were examined. As a skin exposure test we used rubbing with both raw and cooked potato, and used open oral challenge with cooked potato for 7 days. A special eczema scoring system (SCORAD) was used to assess the severity of symptoms and signs of AD. Skin-prick tests (SPTs) were performed with raw potato and natural Sol t 1, and serological studies included measurement of total serum IgE and IgE antibodies to Sol t 1, and potato radioallergosorbent testing (RAST). The skin-rubbing test with raw potato was positive in seven (58%) and the oral challenge positive in eight (67%) infants. One infant presented with an immediate reaction and seven with a delayed reaction, i.e. exacerbation of AD, after oral challenge responses to cooked potato. Nine (75%) infants had IgE antibodies to Sol t 1 in enzyme-linked immunosorbent assay (ELISA), and SPT to natural Sol t 1 was positive in six (50%) potato-allergic infants. In conclusion, we observed positive challenge responses to both raw and cooked potato in food-allergic atopic infants. The presence of IgE antibodies and concomitant positive SPTs to the heat-stable potato allergen, Sol t 1, suggest that cooked potato can be an allergenic food for infants suffering from AD

↩

[46] - Beezhold DH, Sussman GL, Liss GM, Chang NS. Latex allergy can induce clinical reactions to specific foods. Clin Exp Allergy 1996;26:416-422

The purpose of this study was to investigate crossreactivity between latex and foods, to identify crossreacting IgE binding proteins, and to assess the clinical significance. METHODS: Forty-seven latex allergic patients and 46 non-latex allergic patient controls were studied. Allergen sensitization was determined by skin-prick testing (SPT) and allergenic proteins were identified by immunoblot reactivity and amino acid sequence analysis. RESULTS: Immunological reactivity to foods was found to be common, occurring in 33 latex-allergic individuals but in only seven controls (P < 0.000001); 100 of 376 (27%) food skin-prick tests were positive in the latex-allergic subjects. Twenty-seven out of 100 positive food SPTs were associated with clinical symptoms. Seventeen patients manifested a clinical allergy to at least one food including 11 with anaphylaxis, and 14 with local sensitivity reactions. Positive food skin tests occurred most frequently with avocado (53%), potato (40%), banana (38%), tomato (28%), chestnut (28%), and kiwi (17%). Latex-allergic patients (23%) recognize a protein that had sequence homology to a broad class of plant proteins known as patatins. Crossreactivity between latex and several potato proteins was observed by immunoblot inhibition analysis. CONCLUSIONS: Sensitization to latex has extensive crossreactivity with certain foods and leads to clinical allergic reactions. Potatoes and tomatoes are newly reported cross-reacting foods. Plant proteins with structural homology to latex proteins may predispose to food allergy.

↩

[47] - Seppälä U, Palosuo T, Kalkkinen N, Seppälä U, Ylitalo L, Reunala T, et al. IgE reactivity to patatin-like allergen, Hev b 7, and to patatin of potato tuber, Sol t 1, in adults and children allergic to natural ruber latex. Allergy 2000;55:266-273

Patients allergic to natural rubber latex (NRL) frequently show positive skin prick tests (SPT) and hypersensitivity reactions to various fruits, such as avocado, banana, and kiwi, as well as to vegetables such as potato. METHODS: Hev b 7 was purified from NRL "C-serum" and Sol t 1 from potato extract, and they were detected by immunoblotting. IgE antibodies to Hev b 7 and Sol t 1 were measured with ELISA in sera from 35 adults and 35 children allergic to NRL. ELISA inhibition and immunoblotting were used to study allergen cross-reactivity. The in vivo reactivity of Hev b 7 and Sol t 1 were demonstrated in the SPT. RESULTS: Seventeen (49%) of the 35 NRL-allergic adults had IgE antibodies to Hev b 7, in contrast to only one of the 35 NRL-allergic children. Fifteen (43%) of the NRL-allergic adults and 29 (83%) of the NRL-allergic children had IgE antibodies to Sol t 1. Ten (29%) of the adult sera showed IgE binding to both Sol t 1 and Hev b 7, and crosswise inhibition tests with pooled sera revealed marked cross-reactivity. In the SPT, both natural Hev b 7 and Sol t 1 were able to produce a wheal and flare reaction. CONCLUSIONS: One-half of the NRL-allergic adults, but only one of the NRL-allergic children, had IgE antibodies to natural Hev b 7. These results suggest that Hev b 7 is an important NRL allergen for adults, but not for children. Elucidation of the clinical importance of the observed cross-reactivity between Hev b 7 and Sol t 1 requires further studies.

↩

[48] - Sowka S, Hafner C, Radauer C, Focke M, Brehler R, Astwood JD, et al. Molecular and immunologic characterization of new isoforms of the Hevea brasiliensis latex allergen Hev b 7: evidence of no cross-reactivity between Hev b 7 isoforms and potato patatin and proteins from avocado and banana. J Allergy Clin Immunol 1999;104:1302-1310

Hev b 7 is a Hevea brasiliensis latex allergen with sequence identities of 39% to 42% to patatins recently identified as potato allergens. The complementary DNAs encoding 2 different Hev b 7 isoforms were previously reported. OBJECTIVE: The aim of this study was to determine the sequence variation of Hev b 7 and to compare the IgE reactivity of individual isoforms in vitro and in vivo. A further objective was to evaluate possible cross-reactivities between Hev b 7 and patatins and proteins from banana and avocado. METHODS: An H brasiliensis lambda ZAP complementary DNA (cDNA) library was screened with use of a Hev b 7 cDNA probe. Four Hev b 7 isoforms were produced in recombinant form and their IgE-binding capacities were compared. IgE immunoblot inhibitions and ELISA inhibition assays were used to investigate the possible cross-reactivity between Hev b 7 and recombinant potato patatin and proteins from avocado and banana. RESULTS: Two new isoforms, S2 and D2, were identified by sequencing 32 cDNA clones with full-length coding regions. All 4 recombinant isoforms displayed esterase activity and identical IgE-binding capacities. The new isoforms S2 and D2 were evaluated in skin prick tests and provoked responses equivalent to natural Hev b 7. No cross-reactivity was observed between Hev b 7 isoforms and potato patatin and proteins from avocado and banana. CONCLUSIONS: All 4 recombinant Hev b 7 isoforms have equivalent IgE-binding capacity and therefore represent suitable reagents for the development of in vitro and in vivo diagnostic tests. Hev b 7, patatins, and their homologs appear not to contribute to cross-reactivity in the latex-fruit syndrome.

↩

[49] - Sowka S, Hafner C, Radauer C, Focke M, Brehler R, Astwood JD, et al. Molecular and immunologic characterization of new isoforms of the Hevea brasiliensis latex allergen Hev b 7: evidence of no cross-reactivity between Hev b 7 isoforms and potato patatin and proteins from avocado and banana. J Allergy Clin Immunol 1999;104:1302-1310

Hev b 7 is a Hevea brasiliensis latex allergen with sequence identities of 39% to 42% to patatins recently identified as potato allergens. The complementary DNAs encoding 2 different Hev b 7 isoforms were previously reported. OBJECTIVE: The aim of this study was to determine the sequence variation of Hev b 7 and to compare the IgE reactivity of individual isoforms in vitro and in vivo. A further objective was to evaluate possible cross-reactivities between Hev b 7 and patatins and proteins from banana and avocado. METHODS: An H brasiliensis lambda ZAP complementary DNA (cDNA) library was screened with use of a Hev b 7 cDNA probe. Four Hev b 7 isoforms were produced in recombinant form and their IgE-binding capacities were compared. IgE immunoblot inhibitions and ELISA inhibition assays were used to investigate the possible cross-reactivity between Hev b 7 and recombinant potato patatin and proteins from avocado and banana. RESULTS: Two new isoforms, S2 and D2, were identified by sequencing 32 cDNA clones with full-length coding regions. All 4 recombinant isoforms displayed esterase activity and identical IgE-binding capacities. The new isoforms S2 and D2 were evaluated in skin prick tests and provoked responses equivalent to natural Hev b 7. No cross-reactivity was observed between Hev b 7 isoforms and potato patatin and proteins from avocado and banana. CONCLUSIONS: All 4 recombinant Hev b 7 isoforms have equivalent IgE-binding capacity and therefore represent suitable reagents for the development of in vitro and in vivo diagnostic tests. Hev b 7, patatins, and their homologs appear not to contribute to cross-reactivity in the latex-fruit syndrome.

↩

[50] - Reche M, Pascual CY, Vicente J, Caballero T, Muñoz FM, Sanchez S, et al. Tomato allergy in children and young adults: cross-reactivity with latex and potato. Allergy 2001;56:1197-1201

Background: Several studies have shown that allergy to natural rubber latex is associated with cross-reactivity to certain foods such as tomato and potato. The objective was to investigate the clinical and immunologic differences between a group of patients with clinical allergy to tomato and latex and another which had only clinical allergy to tomato. We also aimed to assess, in vitro, the relationship of tomato and latex allergens, which could explain the cross-reactivity. Methods: Forty patients with histories of adverse reactions to tomato and IgE-mediated hypersensitivity were enrolled in the study. Tomato, latex, and potato components were analyzed by SDSˆPAGE immunoblotting. CAP and immunoblot inhibition were used to study allergen cross-reactivity. Results: Patients from group A had a mean age of 13.2 years, and in group B the mean age was 21.7 years. In group B, 9/10 patients belonged to the latex-fruits syndrome. All patients of both groups tolerated potato. Immunoblotting patterns obtained with patients' sera from pool A showed IgE-binding bands to tomato ranging from 44 to 46 kDa and a triple band at 67 kDa. For latex, there was a strong binding at 44 kDa, and potato showed a strong band of 44 kDa and a 67-kDa triple band. In pool B, the binding to the band of 44 kDa in latex and tomato was more intense than in pool A. In pool A, immunoblot inhibition with potato allergen showed an intense inhibition of the three allergens (potato, latex, and tomato); with latex, inhibition was partial and with tomato, a complete inhibition of tomato and latex was observed, and a partial inhibition of potato. In pool B, the inhibition pattern followed a similar tendency to pool A. The CAP inhibition confirmed the high rate of cross-reactivity between tomato, potato, and latex. Conclusions: In our study, tomato, potato, and latex showed a common band of 44ˆ46 kDa probably corresponding to patatin. This protein could be implicated in the high cross-reactivity between tomato, latex, and potato observed in the immunoblot and CAP inhibition.

↩

[51] - Schmidt MH, Raulf-Heimsoth M, Posch A. Evaluation of patatin as a major cross-reactive allergen in latex-induced potato allergy. Ann Allergy Asthma Immunol 2002;89:613-618

BACKGROUND: Potential cross-reactions between natural rubber latex and fruit/vegetable specific immunoglobulin (Ig)E antibodies have been reported for many years. This study was designed to investigate the molecular basis of acquired food sensitization focusing on the storage protein patatin and the patatin-like latex protein Hev b 7. OBJECTIVE: The amount of potato-specific IgE in the serum of latex-allergic health care workers and children with atopic dermatitis was determined to evaluate cross-reactivity between Hev b 7 and patatin. Additionally, the stability of potato patatin to digestion was investigated. METHODS: Human serum was tested on its reactivity to latex and potato proteins by IgE immunoblotting after one-dimensional (1-D) and 2-D electrophoresis. Latex- and potato-specific IgE concentrations were measured in fluorescence enzyme immunoassays (CAP, Pharmacia, Uppsala, Sweden). Further, potato patatin was chromatographically isolated to perform auto-inhibition tests. Stability of patatin to degradation was determined by digestion in vitro. RESULTS: Patatin was identified as major cross-reactive potato allergen by N-terminal sequencing. Seventy-five percent of the potato-sensitized people reacted with patatin in 1-D immunoblots, and 25% of the positive reactions to Hev b 7 could be blocked by preincubation of the patients' sera with purified potato patatin. Examination of children with atopic dermatitis showed that most sera contained patatin-specific IgE, whereas no Hev b 7-specific IgE was detected. Finally, patatin has been found partially stable to digestion in vitro. CONCLUSIONS: Patatin was identified as a major cross-reactive protein in latex-associated potato allergy and appears to be relevant for atopic dermatitis. Therefore, patatin could be a suitable marker for the determination of potato sensitization, and it may also constitute an important food allergen. Cross-reactivity between Hev b 7 and patatin was restricted to primarily latex-sensitized adults, suggesting a different mechanism of sensitization in children with atopic dermatitis

↩

Les allergènes de pomme de terre

Latex et pomme de terre

Rubriques

Dans la même rubrique

Les Solanacées : généralités

La tomate