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The Difference of Allergic Reactions Compared between BN Rats and Wistar Rats on Oral Exposure to Ovalbumin
AB174 Abstracts
657
MONDAY
Filaggrin Mutations are Associated with an Increased Risk of Infantile Food Allergy and Sensitization T. Tan1,2, J. A. Ellis1,3, J. J. Koplin1, P. E. Martin1,2, T. D. Dang1,2, M. C. Matheson4, S. Dharmage1,4, A. Lowe1,4, M. Tang1,5, M. Robinson5, A. Ponsonby1, N. Osborne6, D. Hill1, K. J. Allen1,5; 1Murdoch Childrens Research Institute, Melbourne, AUSTRALIA, 2Department of Paediatrics, University of Melbourne, Melbourne, AUSTRALIA, 3Department of Physiology, University of Melbourne, Melbourne, AUSTRALIA, 4Centre for Molecular, Environmental, Genetic and Analytic Epidemiology, University of Melbourne, Melbourne, AUSTRALIA, 5Department of Allergy and Immunology, Royal Children’s Hospital, Melbourne, AUSTRALIA, 6 European Centre for Environment and Human Health, Peninsula College of Medicine and Dentistry, University of Exeter, Exeter, UNITED KINGDOM. RATIONALE: Filaggrin is central to skin barrier maintenance and filaggrin (FLG) mutations increase the risk of eczema, a condition associated with IgE-mediated food allergy. Recently, FLG mutations were shown to increase the risk of peanut allergy (Brown et al., 2011) although other foods were not assessed. We aimed to determine whether FLG mutations increase the risk of challenge-proven food allergy (egg, peanut and/ or sesame allergy) in a population cohort of one-year-old infants. METHODS: 5302 one-year-old infants recruited from the population underwent skin prick tests (SPT) for egg, peanut and sesame and those sensitized underwent oral food challenge (OFC) to those foods. DNA from 627 Caucasian infants (n5308 with challenge-confirmed food allergy to peanut, egg and/or sesame; n5213 with positive SPT but negative OFC; and n5106 with negative SPT and negative OFC) were genotyped for five FLG mutations (R501X, 2282del4, R2447X, S3247X and 3702delG) using Sequenom MassARRAY. Logistic regression was used for case-control analyses comparing infants with negative SPT and OFC (controls) with sensitized and/or allergic infants (cases). RESULTS: The presence of at least one of the above FLG mutations was associated with an increased risk of developing both food sensitization (OR52.9; 95% CI51.1-7.3) and challenge-confirmed food allergy (OR52.8; 95% CI51.1-7.4). CONCLUSIONS: FLG mutations increase the risk of food allergy and food sensitization to egg, peanut and sesame in infants recruited from the general population. Further work elucidating the role of eczema in the association between FLG mutations and food sensitization/allergy is ongoing.
658
The Skin Is A Potent Site Of Allergic Sensitization To Multiple Food Allergens D. Dunkin, K. Jarvinen, W. Wang, H. Sampson, L. Mayer, C. Berin; The Mount Sinai School of Medicine, New York, NY. RATIONALE: We previously found that mice could be sensitized to milk allergens via the skin in the presence of an adjuvant. Our aim was to investigate the sensitizing potential of multiple food allergens through the skin, and to determine if the atopic dermatitis-associated toxin SEB could provide adjuvant activity. METHODS: Abdominal hair of mice was removed with depilatory cream before application of antigen (0.1 - 1mg) 6 SEB (10 microg) without occlusive dressings, once a week for 6 weeks. Purified antigens included ALA, ovalbumin (OVA), Arah1, and Arah2, and crude extracts included peanut and soy. Mice were challenged by oral or systemic routes, and anaphylaxis measured by body temperature. RESULTS: There was a differential response to allergens applied to the skin. Mice exposed to peanut, Arah2, and OVA developed antigen-specific IgE and IgG1 and anaphylaxis in the absence of an adjuvant. Mice exposed to soy, Arah1, and ALA alone developed weak sensitization and no anaphylaxis, however the presence of SEB enhanced sensitization to ALA and soy, and anaphylaxis to ALA. Sensitization to OVA was independent of TLR4, and unlike models using tape-stripping to abrade the skin, was independent of TSLP. CONCLUSIONS: Food antigens with known strong allergenic potential can sensitize mice in an adjuvant-independent manner through the skin. The presence of SEB can promote allergic sensitization to allergens that
J ALLERGY CLIN IMMUNOL FEBRUARY 2012
have poor sensitizing potential. These data show that the skin is a potent site of sensitization to food allergens. We speculate that in patients with atopic dermatitis, SEB can enhance sensitization to weak allergens.
659
High Molecular Weight Glutenin, Tri a 26, Is An Important Allergen Component In Children With Immediate Allergy To Wheat C. Eriksson1, M. Lundberg2, A. Tanka3, H. Takahashi4, E. Morita4, K. Ito5; 1Thermo Fisher Scientific, ImmunoDiagnostics, R&D, Uppsala, SWEDEN, 2Thermo Fisher Scientific, ImmunoDiagnostics, Uppsala, SWEDEN, 3Thermo Fisher Scientific, ImmunoDiagnostics, Tokyo, JAPAN, 4Department of Dermatology, Shimane University, Izumo, JAPAN, 5 Aichi Childrens Health and Medical Center, Obu, JAPAN. RATIONALE: Omega-5 gliadin (Tri a 19) is a major allergen component in children with immediate allergy to ingested wheat. A fraction of patients with immediate wheat allergy however lack specific IgE (sIgE) to omega-5 gliadin. The aim of this study was to evaluate the importance of the wheat component high molecular weight (HMW) glutenin (Tri a 26) in immediate wheat allergy and in particular for those patients lacking sIgE to omega-5 gliadin. METHODS: Recombinant full-length HMW glutenin was attached to the ImmunoCAP matrix. Sera from 50 Japanese children with immediate wheat allergy were analyzed for sIgE to HMW glutenin and to omega-5 gliadin. RESULTS: Sixty percent (30/50) of the children with immediate wheat allergy had sIgE to the rHMW glutenin and 80% (40/50) had sIgE to omega-5 gliadin. Six out of the 10 children (60%) without detectable levels of sIgE to omega-5 gliadin had sIgE to HMW glutenin. CONCLUSIONS: In this study HMW glutenin and omega-5 gliadin are both major allergen components for Japanese children with immediate allergy to wheat. Ninety-two percent of the patients have sIgE to either omega-5 gliadin or HMW glutenin or both. Simultaneous measurement of sIgE to omega-5 gliadin and HMW glutenin could thus be a helping tool in diagnosis of immediate allergy to wheat.
660
The Difference of Allergic Reactions Compared between BN Rats and Wistar Rats on Oral Exposure to Ovalbumin N. Sun1, C. Zhou1, Q. K. Pu2, J. Wang1, H. L. Che1,3; 1College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, CHINA, 2College of Engineering, China Agricultural University, Beijing, CHINA, 3The Supervision, Inspection and Testing Center of Genetically Modified Organisms, Ministry of Agriculture, Beijing, CHINA. RATIONALE: There is currently no validated animal model for evaluating the allergenic potential of food proteins. This study aimed to investigate the difference of allergic reactions between BN rats and Wistar rats on oral exposure to ovalbumin by studying immune responses and clinical manifestation. METHODS: Female BN and Wistar rats were orally exposed to OVA at Days 1, 14, 15-42. Sera and plasma were screened for measurement of OVA-specific antibody titers (IgE, IgG and IgG2a) and histamine measured by ELISA. After the induction period, the animals were not exposed to OVA for 1 week. On Day 49, all the OVA-sensitized animals were orally challenged with OVA and observed blood pressure, eletrocardio and histopathologic changes. RESULTS: Oral exposure of BN rats to OVA rendered IgE, IgG and IgG2a antibody responses which were generally of higher levels than those observed in Wistar rats(P<0.05). However, plasma histamine level in Wistar rats was significantly higher when compared to BN rats(P<0.05). The Wistar rat elicited more serious clinical manifestation of OVA-induced anaphylaxis. In addition, histopathologic changes detected in the BN rat mainly included diffuse steatosis in heart tissues and eosinophil infiltration in lung tissues, while the Wistar rat showed steatosis in heart and liver tissues, macrophage proliferation in spleen tissues, slight interstitial pneumonia and tubulointerstitial nephritis. CONCLUSIONS: OVA-sensitized BN and Wistar rats showed different immune responses and clinical manifestation, which suggested that the two rat strains may differ in the immunologic mechanism of allergy and there is no correlation between immune responses and the severity of clinical symptoms.
657
MONDAY
Filaggrin Mutations are Associated with an Increased Risk of Infantile Food Allergy and Sensitization T. Tan1,2, J. A. Ellis1,3, J. J. Koplin1, P. E. Martin1,2, T. D. Dang1,2, M. C. Matheson4, S. Dharmage1,4, A. Lowe1,4, M. Tang1,5, M. Robinson5, A. Ponsonby1, N. Osborne6, D. Hill1, K. J. Allen1,5; 1Murdoch Childrens Research Institute, Melbourne, AUSTRALIA, 2Department of Paediatrics, University of Melbourne, Melbourne, AUSTRALIA, 3Department of Physiology, University of Melbourne, Melbourne, AUSTRALIA, 4Centre for Molecular, Environmental, Genetic and Analytic Epidemiology, University of Melbourne, Melbourne, AUSTRALIA, 5Department of Allergy and Immunology, Royal Children’s Hospital, Melbourne, AUSTRALIA, 6 European Centre for Environment and Human Health, Peninsula College of Medicine and Dentistry, University of Exeter, Exeter, UNITED KINGDOM. RATIONALE: Filaggrin is central to skin barrier maintenance and filaggrin (FLG) mutations increase the risk of eczema, a condition associated with IgE-mediated food allergy. Recently, FLG mutations were shown to increase the risk of peanut allergy (Brown et al., 2011) although other foods were not assessed. We aimed to determine whether FLG mutations increase the risk of challenge-proven food allergy (egg, peanut and/ or sesame allergy) in a population cohort of one-year-old infants. METHODS: 5302 one-year-old infants recruited from the population underwent skin prick tests (SPT) for egg, peanut and sesame and those sensitized underwent oral food challenge (OFC) to those foods. DNA from 627 Caucasian infants (n5308 with challenge-confirmed food allergy to peanut, egg and/or sesame; n5213 with positive SPT but negative OFC; and n5106 with negative SPT and negative OFC) were genotyped for five FLG mutations (R501X, 2282del4, R2447X, S3247X and 3702delG) using Sequenom MassARRAY. Logistic regression was used for case-control analyses comparing infants with negative SPT and OFC (controls) with sensitized and/or allergic infants (cases). RESULTS: The presence of at least one of the above FLG mutations was associated with an increased risk of developing both food sensitization (OR52.9; 95% CI51.1-7.3) and challenge-confirmed food allergy (OR52.8; 95% CI51.1-7.4). CONCLUSIONS: FLG mutations increase the risk of food allergy and food sensitization to egg, peanut and sesame in infants recruited from the general population. Further work elucidating the role of eczema in the association between FLG mutations and food sensitization/allergy is ongoing.
658
The Skin Is A Potent Site Of Allergic Sensitization To Multiple Food Allergens D. Dunkin, K. Jarvinen, W. Wang, H. Sampson, L. Mayer, C. Berin; The Mount Sinai School of Medicine, New York, NY. RATIONALE: We previously found that mice could be sensitized to milk allergens via the skin in the presence of an adjuvant. Our aim was to investigate the sensitizing potential of multiple food allergens through the skin, and to determine if the atopic dermatitis-associated toxin SEB could provide adjuvant activity. METHODS: Abdominal hair of mice was removed with depilatory cream before application of antigen (0.1 - 1mg) 6 SEB (10 microg) without occlusive dressings, once a week for 6 weeks. Purified antigens included ALA, ovalbumin (OVA), Arah1, and Arah2, and crude extracts included peanut and soy. Mice were challenged by oral or systemic routes, and anaphylaxis measured by body temperature. RESULTS: There was a differential response to allergens applied to the skin. Mice exposed to peanut, Arah2, and OVA developed antigen-specific IgE and IgG1 and anaphylaxis in the absence of an adjuvant. Mice exposed to soy, Arah1, and ALA alone developed weak sensitization and no anaphylaxis, however the presence of SEB enhanced sensitization to ALA and soy, and anaphylaxis to ALA. Sensitization to OVA was independent of TLR4, and unlike models using tape-stripping to abrade the skin, was independent of TSLP. CONCLUSIONS: Food antigens with known strong allergenic potential can sensitize mice in an adjuvant-independent manner through the skin. The presence of SEB can promote allergic sensitization to allergens that
J ALLERGY CLIN IMMUNOL FEBRUARY 2012
have poor sensitizing potential. These data show that the skin is a potent site of sensitization to food allergens. We speculate that in patients with atopic dermatitis, SEB can enhance sensitization to weak allergens.
659
High Molecular Weight Glutenin, Tri a 26, Is An Important Allergen Component In Children With Immediate Allergy To Wheat C. Eriksson1, M. Lundberg2, A. Tanka3, H. Takahashi4, E. Morita4, K. Ito5; 1Thermo Fisher Scientific, ImmunoDiagnostics, R&D, Uppsala, SWEDEN, 2Thermo Fisher Scientific, ImmunoDiagnostics, Uppsala, SWEDEN, 3Thermo Fisher Scientific, ImmunoDiagnostics, Tokyo, JAPAN, 4Department of Dermatology, Shimane University, Izumo, JAPAN, 5 Aichi Childrens Health and Medical Center, Obu, JAPAN. RATIONALE: Omega-5 gliadin (Tri a 19) is a major allergen component in children with immediate allergy to ingested wheat. A fraction of patients with immediate wheat allergy however lack specific IgE (sIgE) to omega-5 gliadin. The aim of this study was to evaluate the importance of the wheat component high molecular weight (HMW) glutenin (Tri a 26) in immediate wheat allergy and in particular for those patients lacking sIgE to omega-5 gliadin. METHODS: Recombinant full-length HMW glutenin was attached to the ImmunoCAP matrix. Sera from 50 Japanese children with immediate wheat allergy were analyzed for sIgE to HMW glutenin and to omega-5 gliadin. RESULTS: Sixty percent (30/50) of the children with immediate wheat allergy had sIgE to the rHMW glutenin and 80% (40/50) had sIgE to omega-5 gliadin. Six out of the 10 children (60%) without detectable levels of sIgE to omega-5 gliadin had sIgE to HMW glutenin. CONCLUSIONS: In this study HMW glutenin and omega-5 gliadin are both major allergen components for Japanese children with immediate allergy to wheat. Ninety-two percent of the patients have sIgE to either omega-5 gliadin or HMW glutenin or both. Simultaneous measurement of sIgE to omega-5 gliadin and HMW glutenin could thus be a helping tool in diagnosis of immediate allergy to wheat.
660
The Difference of Allergic Reactions Compared between BN Rats and Wistar Rats on Oral Exposure to Ovalbumin N. Sun1, C. Zhou1, Q. K. Pu2, J. Wang1, H. L. Che1,3; 1College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, CHINA, 2College of Engineering, China Agricultural University, Beijing, CHINA, 3The Supervision, Inspection and Testing Center of Genetically Modified Organisms, Ministry of Agriculture, Beijing, CHINA. RATIONALE: There is currently no validated animal model for evaluating the allergenic potential of food proteins. This study aimed to investigate the difference of allergic reactions between BN rats and Wistar rats on oral exposure to ovalbumin by studying immune responses and clinical manifestation. METHODS: Female BN and Wistar rats were orally exposed to OVA at Days 1, 14, 15-42. Sera and plasma were screened for measurement of OVA-specific antibody titers (IgE, IgG and IgG2a) and histamine measured by ELISA. After the induction period, the animals were not exposed to OVA for 1 week. On Day 49, all the OVA-sensitized animals were orally challenged with OVA and observed blood pressure, eletrocardio and histopathologic changes. RESULTS: Oral exposure of BN rats to OVA rendered IgE, IgG and IgG2a antibody responses which were generally of higher levels than those observed in Wistar rats(P<0.05). However, plasma histamine level in Wistar rats was significantly higher when compared to BN rats(P<0.05). The Wistar rat elicited more serious clinical manifestation of OVA-induced anaphylaxis. In addition, histopathologic changes detected in the BN rat mainly included diffuse steatosis in heart tissues and eosinophil infiltration in lung tissues, while the Wistar rat showed steatosis in heart and liver tissues, macrophage proliferation in spleen tissues, slight interstitial pneumonia and tubulointerstitial nephritis. CONCLUSIONS: OVA-sensitized BN and Wistar rats showed different immune responses and clinical manifestation, which suggested that the two rat strains may differ in the immunologic mechanism of allergy and there is no correlation between immune responses and the severity of clinical symptoms.