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Soares JRA, Pereira E Silva A, de Souza Oliveira AL, Guimarães IM, das Neves Faccini CRJ, de Aquino Mattos EB, Rodrigues SKPM, Marmello BO, Teixeira GAPB. Allergen extraction: Factors influencing immunogenicity and sensitivity of immunoassays. J Immunol Methods 2021; 498:113125. [PMID: 34450115 DOI: 10.1016/j.jim.2021.113125] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 08/17/2021] [Accepted: 08/17/2021] [Indexed: 10/20/2022]
Abstract
Food allergy prevalence is increasing worldwide, therefore there is a high demand for reliable tests to correctly diagnose this disease. Knowledge of proteins allergenicity and how they react both in the body and in diagnostic tests is necessary to adequately assess the potential immunogenicity of both natural foods and those produced through biotechnological processes. Thus, our aim was to analyze the factors that influence the protein extraction of foods in terms of, immunogenicity and immunoassays sensitivity. Peanut proteins were extracted using four distinct extraction buffers with different pH values (physiological saline, tris buffer, borate buffer with and without β-mercaptoethanol), the protein concentration was determined by the Lowry method and polyacrylamide electrophoresis (SDS-PAGE) was used to compare the protein profile of each extract. The immunogenicity of each extract was verified by sensitizing two mouse strains (Balb/c and C57Bl/6) with a solution containing 100 μg of the extracted proteins and was determined by ELISA. Results show that extraction with the distinct buffers resulted in protein solutions with different yields and profiles. The immunogenicity of the different extracts also demonstrated distinct patterns that varied depending on the extraction methods, mouse strain and in vitro test. Immunoreactivity varied in accordance with the protein extract used to coat the microtitration plates. In conclusion, the protein profile in the extracts is critically influenced by the salt composition and pH of the extraction buffers, this in turn influences both in vivo immunogenicity and in vitro immunoreactivity.
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Affiliation(s)
- João Ricardo Almeida Soares
- Gastrointestinal Immunology Group, Department of Immunobiology, Institute of Biology, Federal Fluminense University, Niterói, Rio de Janeiro 24020-150, Brazil; Graduate Program in Pathology, Medicine School, Antônio Pedro Hospital, Federal Fluminense University, Niterói, Rio de Janeiro 24033-900, Brazil
| | - Airton Pereira E Silva
- Gastrointestinal Immunology Group, Department of Immunobiology, Institute of Biology, Federal Fluminense University, Niterói, Rio de Janeiro 24020-150, Brazil; Graduate Program in Pathology, Medicine School, Antônio Pedro Hospital, Federal Fluminense University, Niterói, Rio de Janeiro 24033-900, Brazil
| | - Ana Luísa de Souza Oliveira
- Gastrointestinal Immunology Group, Department of Immunobiology, Institute of Biology, Federal Fluminense University, Niterói, Rio de Janeiro 24020-150, Brazil; Graduate Program in Pathology, Medicine School, Antônio Pedro Hospital, Federal Fluminense University, Niterói, Rio de Janeiro 24033-900, Brazil
| | - Isabelle Mazza Guimarães
- Gastrointestinal Immunology Group, Department of Immunobiology, Institute of Biology, Federal Fluminense University, Niterói, Rio de Janeiro 24020-150, Brazil; Graduate Program in Science and Biotechnology, Federal Fluminense University, Niterói, Rio de Janeiro 24020-141, Brazil
| | - Claudia Regina Josetti das Neves Faccini
- Gastrointestinal Immunology Group, Department of Immunobiology, Institute of Biology, Federal Fluminense University, Niterói, Rio de Janeiro 24020-150, Brazil; Graduate Program in Pathology, Medicine School, Antônio Pedro Hospital, Federal Fluminense University, Niterói, Rio de Janeiro 24033-900, Brazil
| | - Erika Bertozzi de Aquino Mattos
- Gastrointestinal Immunology Group, Department of Immunobiology, Institute of Biology, Federal Fluminense University, Niterói, Rio de Janeiro 24020-150, Brazil; Graduate Program in Pathology, Medicine School, Antônio Pedro Hospital, Federal Fluminense University, Niterói, Rio de Janeiro 24033-900, Brazil
| | - Sónia Kristy Pinto Melo Rodrigues
- Gastrointestinal Immunology Group, Department of Immunobiology, Institute of Biology, Federal Fluminense University, Niterói, Rio de Janeiro 24020-150, Brazil; Graduate Program in Pathology, Medicine School, Antônio Pedro Hospital, Federal Fluminense University, Niterói, Rio de Janeiro 24033-900, Brazil
| | - Bárbara Oliveira Marmello
- Gastrointestinal Immunology Group, Department of Immunobiology, Institute of Biology, Federal Fluminense University, Niterói, Rio de Janeiro 24020-150, Brazil; Graduate Program in Science and Biotechnology, Federal Fluminense University, Niterói, Rio de Janeiro 24020-141, Brazil
| | - Gerlinde Agate Platais Brasil Teixeira
- Gastrointestinal Immunology Group, Department of Immunobiology, Institute of Biology, Federal Fluminense University, Niterói, Rio de Janeiro 24020-150, Brazil; Graduate Program in Science and Biotechnology, Federal Fluminense University, Niterói, Rio de Janeiro 24020-141, Brazil; Graduate Program in Pathology, Medicine School, Antônio Pedro Hospital, Federal Fluminense University, Niterói, Rio de Janeiro 24033-900, Brazil.
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Differences among heat-treated, raw, and commercial peanut extracts by skin testing and immunoblotting. Ann Allergy Asthma Immunol 2011; 105:451-7. [PMID: 21130383 DOI: 10.1016/j.anai.2010.09.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Revised: 09/25/2010] [Accepted: 09/27/2010] [Indexed: 11/22/2022]
Abstract
BACKGROUND Peanut allergenicity has been reported to be influenced by heat treatment, yet the commonly available extracts for skin prick testing (SPT) are derived from raw extracts. OBJECTIVE To assess the effect of heat treatment on the SPT reactivity and specific IgE binding to peanut. METHODS Three commercial extracts and 3 laboratory-prepared extracts, including raw, roasted, and boiled, were used for SPT in 19 patients with suspected peanut allergy and in 4 individuals who eat peanut without any symptoms. Serum samples were obtained to measure total IgE in addition to specific IgE binding to the study extracts by immunoblotting. Peanut allergy was confirmed with challenge test unless the individual had a convincing history of a severe reaction. RESULTS Eleven study participants were considered peanut allergic based on a strong history or positive challenge test result. SPT with the prepared and commercial reagents showed that the boiled extract had the highest specificity (67% vs 42%-63% for the other extracts). The prepared extracts showed similar SPT sensitivity (81%). Three patients with a history of severe reaction and elevated specific IgE levels to peanut to the 3 study extracts had variable SPT reactivity to 1 or more of the commercial extracts. IgE binding to Ara h 2 was found in nearly all patients, regardless of their clinical reactivity. CONCLUSIONS None of the extracts tested showed optimal diagnostic reliability regarding both sensitivity and specificity. Perhaps testing should be performed with multiple individual extracts prepared by different methods.
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Bullock RJ, Barnett D, Howden MEH. Immunologic and clinical responses to parenteral immunotherapy in peanut anaphylaxis--a study using IgE and IgG4 immunoblot monitoring. Allergol Immunopathol (Madr) 2005; 33:250-6. [PMID: 16287543 DOI: 10.1157/13080927] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
BACKGROUND Specific desensitisation to food allergens, which produce anaphylaxis after ingestion, has not been considered as a treatment for food allergy until recently. The purpose of this study was to assess if a parenteral immunotherapy program, using a partially characterised crude peanut extract, could induce a state of immunological tolerance in a patient who exhibited anaphylaxis, asthma and urticaria on exposure to peanut and other legumes. A further aim was to measure the serum antibody responses to the immunotherapy. METHODS AND RESULTS We report the successful desensitisation towards all of the legumes tested of a male patient on parenteral immunotherapy using a partially characterised peanut extract. The immunologic parameters measured during treatment included specific IgE and IgG4 for peanut, soybean, pea and lentil extracts. Immunoblots of specific IgE and IgG4 were made before and after therapy. The antibody response followed the same pattern seen in successful desensitisation of patients with bee venom anaphylaxis. The IgG4 levels increased strongly from a low pre-treatment level in proportion to the antigen dose received. The antigen-specific IgE levels gradually fell from a high pretreatment level, but remained significantly elevated. Immunoblotting for specific IgE and IgG4 demonstrated that acquisition of clinical tolerance after therapy was associated with declines in the number and intensity of bands in IgE blots and the development of more bands of increasing density in the IgG4 blots. CONCLUSIONS Parenteral immunotherapy may offer an alternative treatment to lifelong dietary restriction and epinephrine injections in patients who exhibit life-threatening IgE-mediated anaphylaxis to peanut. Cross desensitisation to other legumes appears to have occurred in this study. The quality and potency of the extract used is an important factor in achieving the desired acquisition of clinical tolerance. In our patient this tolerance correlated with his ability to maintain high levels of specific IgG4, which acted as a marker of protection against anaphylaxis. The use of IgG4 immunoblotting may provide an improved level of discrimination in the assessment of correlation of clinical efficacy with the immunologic response.
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Affiliation(s)
- R J Bullock
- Department of Clinical Immunology and Allergy, Repatriation General Hospital, Concord, NSW 2139, Australia
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Pereira MJ, Belver MT, Pascual CY, Martín Esteban M. [The allergenic significance of legumes]. Allergol Immunopathol (Madr) 2002; 30:346-53. [PMID: 12464170 DOI: 10.1016/s0301-0546(02)79152-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Leguminous are a cheap source of protein that are cultivated practically throughout the world. They are the main source of food in developing countries. In the Mediterranean area and Middle East, the most commonly consumed legumes are lentils and chickpea. In the United States, United Kingdom and south-east Asia, the major legumes involved in food allergy are considered to be peanut and soy bean, respectively. The clinical manifestations of the allergy to legumes are similar for all legumes and range from oral allergy syndrome, urticaria, angioedema, rhinitis and asthmatic crises to anaphylaxis and even death. Legumes have a high degree of immunological cross-reactivity. Severals authors have described cross-reactivity among different legumes and between legumes and various vegetables. The allergenicity of legumes is mainly is mainly related to allergens from the storage proteins of seeds. Vicilins from this group of proteins could be an important common allergen in clinical allergy to legumes. Profilins are considered to be a cause of cross-reactivity among fruits, vegetables and some pollens and are believed to be a panallergen. Other panallergens of increasing importance are lipid transfer proteins. Few studies have assessed the long-term clinical course of allergy to legumes. Novel therapeutic agents are being investigated for the treatment of peanut allergy and these could be applied to other legumes.
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Affiliation(s)
- M J Pereira
- Servicio de Alergia. Hospital Infantil Universitario La Paz. Madrid. España
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Porcel S, León F, Martín Calderín P, Valero A, Botello A, Alvarez Cuesta E. Occupational asthma caused by grass pea used in the industrial processing of parquet. Allergol Immunopathol (Madr) 2001; 29:207-11. [PMID: 11720656 DOI: 10.1016/s0301-0546(01)79058-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND although grass pea belongs to the leguminoseae family, allergic reactions to its flour have rarely been described. Clinical and immunological studies were performed to confirm a type I hypersensitivity mechanism in a case of occupational asthma to grass pea flour exposure, used in the industrial processing of parquet. METHODS occupational asthma was diagnosed according to patient history, PEFR monitoring and a specific bronchial challenge test. Skin prick test with an aqueous grass pea flour extract, specific IgE determinations (CAP assay) and IgE immunoblot tests were performed. RESULTS skin prick test with the extract showed a positive immediate response, and negative response in controls. Specific IgE to grass pea was positive (9.57 KU/l). Immunoblotting demonstrated the presence of specific serum IgE that recognized 3 proteins in the extract (MW 46, 32 and 28 kDa). PEFR monitoring showed positive results. Bronchial challenge test with the extract elicited an isolated immediate response. CONCLUSIONS as far as we know this is the first time that IgE mediated occupational asthma caused by grass pea is reported and it is also the first time that its allergens are characterized. Grass pea flour might constitute a relevant occupational allergen in this unreported source of exposure in parquet manufacturers.
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Affiliation(s)
- S Porcel
- Department of Allergy, Hospital Ramón y Cajal, Madrid, Spain.
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Li XM, Serebrisky D, Lee SY, Huang CK, Bardina L, Schofield BH, Stanley JS, Burks AW, Bannon GA, Sampson HA. A murine model of peanut anaphylaxis: T- and B-cell responses to a major peanut allergen mimic human responses. J Allergy Clin Immunol 2000; 106:150-8. [PMID: 10887318 DOI: 10.1067/mai.2000.107395] [Citation(s) in RCA: 326] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Peanut allergy affects 0.6% of the US population. At the present time, allergen avoidance is the only therapeutic option. Animal models of food-induced anaphylaxis would facilitate attempts to design novel immunotherapeutic strategies for the treatment of peanut allergy. OBJECTIVE The purpose of this study was to develop a murine model of IgE-mediated peanut hypersensitivity that closely mimics human peanut allergy. METHODS C3H/HeJ mice sensitized orally with freshly ground whole peanut and cholera toxin as adjuvant were challenged orally 3 and 5 weeks later with crude peanut extract. Anaphylactic reactions were determined. T- and B-cell responses to Ara h 1 and Ara h 2, the major peanut allergens, were characterized by evaluating splenocyte proliferative responses and IgE antibody concentrations. Furthermore, IgE antibodies in the sera of patients with peanut allergy and mice were compared for antibody binding to Ara h 2 isoforms and allergenic epitopes. RESULTS Peanut-specific IgE was induced by oral peanut sensitization, and hypersensitivity reactions were provoked by feeding peanut to sensitized mice. The symptoms were similar to those seen in human subjects. Ara h 1- and Ara h 2-specific antibodies were present in the sera of mice with peanut allergy. Furthermore, these Ara h 2-specific IgE antibodies bound the same Ara h 2 isoforms and major allergenic epitopes as antibodies in the sera of human subjects with peanut allergy. Splenocytes from mice with peanut allergy exhibited proliferative responses to Ara h 1 and Ara h 2. CONCLUSION This murine model of peanut allergy mimics the clinical and immunologic characteristics of peanut allergy in human subjects and should be a useful tool for developing immunotherapeutic approaches for the treatment of peanut allergy.
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Affiliation(s)
- X M Li
- Department of Pediatrics, Mount Sinai School of Medicine, New York, USA
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Matheu V, de Barrio M, Sierra Z, Gracia-Bara MT, Tornero P, Baeza ML. Lupine-induced anaphylaxis. Ann Allergy Asthma Immunol 1999; 83:406-8. [PMID: 10582721 DOI: 10.1016/s1081-1206(10)62838-4] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
BACKGROUND Legumes are one of the most common foods causing allergic reactions in children and adults. Cross-reacting antibodies are frequently demonstrated in this family but the real clinical cross-reactivity is uncommon. OBJECTIVE To report a case of lupine-induced anaphylaxis and to elucidate in vivo and in vitro cross-reactivity with some legumes. METHODS Skin prick test (SPT) with some legumes were performed. Cap-IgE, ELISA-IgE, and immunoblotting were carried out. Open oral challenges with some legumes were performed. Cross-reactivity was studied by ELISA and immunoblotting inhibition. RESULTS The results demonstrated type-I hypersensitivity reactions with lupine and some other legumes. Cap-IgE with peanut was positive but the SPT and ELISA-IgE were negative and the patient tolerated a peanut challenge. ELISA inhibition revealed a partial inhibition (62%) using lupine as the solid phase. Partial inhibition was demonstrated by immunoblotting inhibition. Open oral challenge with peanut and green bean were negative but positive with pea. CONCLUSION We present a lupine sensitized patient with positive SPT and in vitro cross-reactivity with other legumes. Clinical cross-reactivity progressively developed over a 5-year period. Discrepancies were found between the clinical aspect and in vitro study of peanut allergy. Factors determining the wide variability in cross-reactivity among individuals are still obscure.
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Affiliation(s)
- V Matheu
- Allergy Section, Gregorio Marañón University General Hospital, Madrid, Spain.
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Affiliation(s)
- S L Bahna
- Department of Pediatrics, University of South Florida, All Children's Hospital, St. Petersburg, FL 33701, USA
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Metcalfe DD, Astwood JD, Townsend R, Sampson HA, Taylor SL, Fuchs RL. Assessment of the allergenic potential of foods derived from genetically engineered crop plants. Crit Rev Food Sci Nutr 1996; 36 Suppl:S165-86. [PMID: 8959382 DOI: 10.1080/10408399609527763] [Citation(s) in RCA: 322] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
This article provides a science-based, decision tree approach to assess the allergenic concerns associated with the introduction of gene products into new plant varieties. The assessment focuses on the source from which the transferred gene was derived. Sources fall into three general categories: common allergenic food proteins; less common allergenic foods or other known allergen sources; and sources with no history of allergenicity. Information concerning the amino acid sequence identity to known allergenic proteins, in vitro and/or in vivo immunologic assays, and assessment of key physiochemical properties are included in reaching a recommendation on whether food derived from the genetically modified plant variety should be labeled as to the source of the transferred gene. In the end, a balanced judgement of all the available data generated during allergenicity assessment will assure the safety of foods derived from genetically engineered crops. Using the approaches described here, new plant varieties generated by genetic modification should be introduced into the marketplace with the same confidence that new plant varieties developed by traditional breeding have been introduced for decades.
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Affiliation(s)
- C Loza
- Department of Immunology, University College London Medical School, UK
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12
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Abstract
The clinical laboratory has a well defined role to play in the diagnosis and management of patients with allergy. Elevated serum levels of total IgE and/or allergen-specific IgE indicate that an IgE mediated event has occurred. Methods such as basophil degranulation and basophil or leukocyte histamine release can provide similar information. Sensitive and precise methods suitable for automation are available for quantitation of histamine in whole blood or plasma. Methyl histamine can be assayed in urine. Eosinophil cationic protein levels in serum can be used as an indicator of eosinophil activation in disorders such as asthma and atopic dermatitis. Similarly, serum mast cell tryptase levels can confirm or exclude an anaphylactic reaction both in life and as a cause of death. This review documents and compares commercially available methods for these assays and discusses their application to screening, diagnosis, and management of patients with allergy.
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Affiliation(s)
- M L Salkie
- Department of Laboratory Medicine and Pathology, University of Alberta Hospitals, Edmonton, Canada
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Igea JM, Fernandez M, Quirce S, de la Hoz B, Diez Gomez ML. Green bean hypersensitivity: an occupational allergy in a homemaker. J Allergy Clin Immunol 1994; 94:33-5. [PMID: 8027496 DOI: 10.1016/0091-6749(94)90068-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
As a member of the legume family, the green bean is frequently associated with food allergy. However, allergic reactions caused by skin contact or by inhalation of vapors from boiling legumes are rare. This article presents a case of occupational asthma in a homemaker; symptoms occurred during preparation and cooking of raw green beans. Skin prick, rub, and bronchial provocation tests were performed on the patient. In vitro tests were done with the serum samples of the patient and 10 control subjects (5 atopic and 5 nonatopic). Test results indicate that the patient has type I hypersensitivity to raw green bean antigen(s). This case is of interest because it demonstrates that a food allergen, when inhaled, can induce respiratory symptoms in sensitized patients and may even be the source of primary sensitization.
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Affiliation(s)
- J M Igea
- Servicio de Alergia, Hospital Ramon y Cajal, Madrid, Spain
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Zimmerman B, Forsyth S, Gold M. Highly atopic children: formation of IgE antibody to food protein, especially peanut. J Allergy Clin Immunol 1989; 83:764-70. [PMID: 2708736 DOI: 10.1016/0091-6749(89)90012-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Highly atopic infants often form IgE antibodies toward multiple food protein in the first 2 years of life. They begin producing IgE antibody to inhalant allergens between the first and second year of life. We hypothesized that highly atopic children would be at significant risk of sensitization to peanut. We defined high atopy as serum IgE greater than or equal to 10 times 1 SD from normal plus multiple positive RASTs. In this study we have characterized the immunologic status of 141 patients by measuring total serum IgE and specific IgE to several allergens, including peanut. These data demonstrated that, independent of clinical history, a positive RAST to peanut was more common in the highly atopic category compared to the low atopy category. Significantly more patients who were highly atopic and had a positive peanut RAST had a positive RAST for egg or milk compared to low atopic patients. More significantly, 33 of the patients had never knowingly received peanut, yet 21 (63.6%) had a positive RAST for peanut, whereas seven (21.2%) had a peanut antibody in the highest RAST category. All these seven patients were considered highly atopic according to the definition above, and three were younger than 2 years of age. These results suggest that highly atopic infants are at special risk for sensitization to peanut, even when they have never received peanut, and that characterization of immunologic sensitization to milk, egg, and peanut will identify the highly atopic infant.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- B Zimmerman
- Hospital for Sick Children, Toronto, Ontario, Canada
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Bernhisel-Broadbent J, Sampson HA. Cross-allergenicity in the legume botanical family in children with food hypersensitivity. J Allergy Clin Immunol 1989; 83:435-40. [PMID: 2918186 DOI: 10.1016/0091-6749(89)90130-9] [Citation(s) in RCA: 218] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Sixty-nine patients with one or more positive prick skin tests to legumes (peanut, soybean, green bean, pea, and lima bean) were evaluated for food hypersensitivity with in-hospital oral food challenges. Of the 280 prick skin tests to legumes performed, 130 were positive. Forty-three positive food challenges occurred in 41 patients. The prevalence of legume allergy was not statistically different in those patients (N = 36) with two or more positive legume prick skin test (64% positive) compared to those patients (N = 33) with only one positive legume prick skin test (55% positive; p greater than 0.10). Even in this selected patient population, only two patients had symptomatic hypersensitivity to two legumes. Among patients with a positive prick skin test to peanut (N = 60), the mean wheal size was larger in patients with a positive versus a negative oral food challenge to peanut (p less than 0.001). Results of oral food challenges demonstrate that clinically important cross-reactivity to legumes in children is very rare. Clinical hypersensitivity to one legume does not warrant dietary elimination of all legumes. Results of prick skin tests should not be used to determine prolonged food restriction diets.
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Affiliation(s)
- J Bernhisel-Broadbent
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD 21205
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Barnett D, Bonham B, Howden ME. Allergenic cross-reactions among legume foods--an in vitro study. J Allergy Clin Immunol 1987; 79:433-8. [PMID: 3493279 DOI: 10.1016/0091-6749(87)90359-9] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The specific IgE binding by protein extracts of 11 food legumes, including soybean, was examined by RAST and RAST inhibition. Sera from 15 peanut-sensitive patients were, with very few exceptions, positive in the RAST to all the legumes. RAST-inhibition testing of each extract against RAST discs of the other legumes indicated considerable cross-reactivity of IgE binding between the legumes. Cross-allergenicity was demonstrated to be most marked between the extracts of peanut, garden pea, chick pea, and soybean. The results have important implications for selection of effective hypoallergenic diets and for the diagnosis of patients hypersensitive to foods.
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Abstract
While progress has been made in the areas of food allergen characterization, both the complexity of the biochemical constituents of food and the body's normal physiologic (digestion) and immunologic responses to food ingestion provide challenging obstacles to efforts aimed at developing standardized food extracts. As indicated above, while currently available food extracts can be useful in the evaluation of food hypersensitivity, the results obtained using these reagents are far from optimal. Indeed, in some cases, skin testing after rubbing a small amount of the food on the skin may be more inciteful than using commercially prepared extracts. While this approach may provide physicians with help in terms of diagnosis, purified food components will be necessary to comprehensively study the complex issues of food allergen digestion and absorption; immune response and tolerance to food allergens; and hopefully, treatment and prevention of food hypersensitivity.
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