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Specific Oral Tolerance Induction With A Weekly Updosing Schedule In Children With Ige Mediated Cow's Milk Allergy
S32 Abstracts
SATURDAY
108
Contribution of Structure to IgE Binding by Ara h 2 S. J. Maleki, R. Kado; US Dept. of Agriculture, New Orleans,
LA. RATIONALE: Ara h 2 from roasted peanut binds higher IgE levels than Ara h 2 from raw peanuts (RA2). To determine if structural epitopes are more important for IgE binding to Ara h 2 than linear epitopes, we assessed the denaturation of Ara h 2 (DA2) over time and with temperature and compared the differences in IgE binding to the various folded and unfolded forms of this allergen. METHODS: Ara h 2 was purified from raw peanuts and treated with increasing heat or a denaturing agent, di-thiothreatol (DTT, 2 mM). IgE binding to the various forms of Ara h 2 was compared using sera from peanut allergic and sensitized patients using Western blot analysis. Circular dichroism was used to monitor structural changes. RESULTS: The structure of folded Ara h 2, which is predominantly alpha helical was very similar to the Ara h 2 from roasted peanut. Ara h 2 was resistant to denaturation with heat, but was completely denatured after 24 hours of incubation with DTT and the predominance toward alpha helical secondary structure shifts to random coil. The less structured Ara h 2 with reduced alpha helical structure, the lower the level of IgE binding for majority of patients’ sera. CONCLUSIONS: The chemical modifications incurred by roasting are important for IgE binding while in the in RA2 conformational epitopes seem to be the major contributors to IgE binding. Also, differences in IgE binding to various forms of Ara h 2 by allergic versus sensitized patient sera may be useful in development of more specific diagnostic tools.
109
Specific Oral Tolerance Induction With A Weekly Updosing Schedule In Children With Ige Mediated Cow's Milk Allergy G. B. Pajno1, L. Caminiti1, S. Barberi1, D. Vita1, C. E. Baena-Cagnani2, G. Barberio1, P. Ruggeri3, G. Passalacqua4; 1Department of Pediatrics, Allergy Unit, University of Messina, Italy, 2Catholic University of Cordoba, Cordoba, Argentina, 3Department of Respiratory Diseases, University of Messina, Italy, 4Allergy & Respiratory Diseases DIMI, Genoa University, Genoa, Italy. BACKGROUND: The IgE mediated food allergy is a great burden for patients, particularly for children and their families. Desenzitization procedures have been described, but they are time-consuming and often not practical to do. We examined the possibility of the induction of a Specific Oral Tolerance with Cow’s Milk (CM) by means of a weekly up-dosing schedule. METHODS: 13 children with Immunoglobulin E (IgE) food allergy to CM confirmed by Double Blind Placebo Controlled Food Challenge (DBPCFC) were recruited. The schedule consisted of administering at weekly intervals one drop of whole CM diluted 1:25. Part of the children received a placebo (soy formula). The CM doses were doubled weekly until the 18th week in order to achieve an intake of 200 ml in about 4 months. RESULTS: 10 children received CM and 3 children received soy formula. Oral Tolerance Induction can be achieved by means of weekly administration of CM on 7 children. However in 2 children (20%) this therapeutic approach failed. and 1(10%) patient could take only limited amount f milk: 64 ml. CONCLUSIONS: We have found that specific oral tolerance induction (SOTI) should be a goal for treatment in children with IgE mediated CM Allergy.
J ALLERGY CLIN IMMUNOL FEBRUARY 2009
110
Comparative Study Of Food Allergy In Rural And Urban Chinese School Children G. W. Wong1, Y. Ma2, Y. Chan2, J. Fang3, Y. Li4, Y. Pan5, T. F. Leung1, F. Liu1; 1Chinese University of Hong Kong, Hong Kong, Hong Kong, 2Capital Institute of Pediatrics, Beijing, China, 3Institute for Environmental Hygiene, Beijing, China, 4Sun Yi Center of Disease Control, Beijing, China, 5Dongcheng School Health Care Institute, Beijing, China. RATIONALE: Epidemiological studies have suggested that the prevalence food allergies is on the rise. Research studies also suggested that the rural environment is associated with lower prevalence of asthma. The aim of the current study is to compare the prevalence of self reported food allergies and respiratory symptoms in urban and rural Chinese children. METHODS: Random samples of primary schoolchildren were recruited from Hong Kong, Beijing city and rural Beijing. Parents were asked to complete the validated Chinese version of the ISAAC core questionnaire and the Europrevall Screening questionnaire. RESULTS: A total of 16866 children (Hong Kong 6194, urban Beijing 5948, and rural Beijing 4724) agreed to enroll in the study (participation rate, 87%). The prevalence of self reported food allergies was highest in Hong Kong with 3.9% of children reported to have more than 4 episodes of adverse reaction to foods as compared to 2.0% (P < 0.01) in urban Beijing and 0.9% (P < 0.001) in rural Beijing. The most common reported food allergens in Hong Kong were shrimp (2.2%), egg (0.8%), and mango (0.7%). The prevalence of asthma diagnosis and wheeze ever was highest in Hong Kong (27%) as compared to that in urban Beijing (6%, P < 0.001), and rural Beijing (2.5%, P < 0.001). CONCLUSIONS: This study documented a lower prevalence of self-reported food allergies in rural setting as compared to the urban setting. There is also a strong relationship of asthma diagnosis and self reported food allergies. Further validation studies using skin-prick test and measurement of serum specific IgE are underway to confirm the findings of the current study.
111
Sesame Food Allergy and Sensitization in Children: A Growing Concern in the USA A. Alexis, B. Safier, D. W. Rosenthal, M. A. Cavuoto; Schneider Children’s Hospital, Long Island Jewish Hospital-North Shore University Medical Center, Great Neck, NY. RATIONALE: Sesame allergy has been described as a common food allergen affecting both children and adults mostly in Europe, Canada, Australia and Asia (Israel, Japan). Yet, there is limited data describing sesame allergy in the USA. METHODS: We conducted a retrospective chart review of patients from our Allergy Clinic that had CAP-RAST Class 2 to sesame (f10) and either a strong clinical history of an adverse reaction to sesame or atopic dermatitis. Charts were screened for gender, age at presentation, clinical presentation, CAP-RAST to f10 IgE, concurrent food allergies, history of atopy, and family history of atopy. RESULTS: Seventeen patients (35% Male) were identified. The mean age at first presentation was 6.9 6 11.1 years (range 8 months-44 years). The patients presented with a strong clinical history of an IgE-medicated reaction after the ingestion of sesame (13/17) or a history of atopic dermatitis (4/17). The most common presentation of the patients with a clinical history (13/17) was urticaria (46%), followed by angioedema (31%), gastrointestinal (15%) and respiratory (8%) manifestations. Of these patients 94% had a strong family history of atopy, 70% were also diagnosed with tree nut allergy, 65% with peanut allergy, 50% with asthma, and 30% with allergic rhinitis. CONCLUSIONS: Sesame allergy can cause severe IgE-mediated reactions and its prevalence is increasing worldwide. In our study we present seventeen patients with sesame allergy and characterize their presentation. Unlike peanut allergy there is little awareness of this allergen in the USA. It is imperative to educate patients, parents as well as providers about the risks associated with sesame allergy in the USA.
SATURDAY
108
Contribution of Structure to IgE Binding by Ara h 2 S. J. Maleki, R. Kado; US Dept. of Agriculture, New Orleans,
LA. RATIONALE: Ara h 2 from roasted peanut binds higher IgE levels than Ara h 2 from raw peanuts (RA2). To determine if structural epitopes are more important for IgE binding to Ara h 2 than linear epitopes, we assessed the denaturation of Ara h 2 (DA2) over time and with temperature and compared the differences in IgE binding to the various folded and unfolded forms of this allergen. METHODS: Ara h 2 was purified from raw peanuts and treated with increasing heat or a denaturing agent, di-thiothreatol (DTT, 2 mM). IgE binding to the various forms of Ara h 2 was compared using sera from peanut allergic and sensitized patients using Western blot analysis. Circular dichroism was used to monitor structural changes. RESULTS: The structure of folded Ara h 2, which is predominantly alpha helical was very similar to the Ara h 2 from roasted peanut. Ara h 2 was resistant to denaturation with heat, but was completely denatured after 24 hours of incubation with DTT and the predominance toward alpha helical secondary structure shifts to random coil. The less structured Ara h 2 with reduced alpha helical structure, the lower the level of IgE binding for majority of patients’ sera. CONCLUSIONS: The chemical modifications incurred by roasting are important for IgE binding while in the in RA2 conformational epitopes seem to be the major contributors to IgE binding. Also, differences in IgE binding to various forms of Ara h 2 by allergic versus sensitized patient sera may be useful in development of more specific diagnostic tools.
109
Specific Oral Tolerance Induction With A Weekly Updosing Schedule In Children With Ige Mediated Cow's Milk Allergy G. B. Pajno1, L. Caminiti1, S. Barberi1, D. Vita1, C. E. Baena-Cagnani2, G. Barberio1, P. Ruggeri3, G. Passalacqua4; 1Department of Pediatrics, Allergy Unit, University of Messina, Italy, 2Catholic University of Cordoba, Cordoba, Argentina, 3Department of Respiratory Diseases, University of Messina, Italy, 4Allergy & Respiratory Diseases DIMI, Genoa University, Genoa, Italy. BACKGROUND: The IgE mediated food allergy is a great burden for patients, particularly for children and their families. Desenzitization procedures have been described, but they are time-consuming and often not practical to do. We examined the possibility of the induction of a Specific Oral Tolerance with Cow’s Milk (CM) by means of a weekly up-dosing schedule. METHODS: 13 children with Immunoglobulin E (IgE) food allergy to CM confirmed by Double Blind Placebo Controlled Food Challenge (DBPCFC) were recruited. The schedule consisted of administering at weekly intervals one drop of whole CM diluted 1:25. Part of the children received a placebo (soy formula). The CM doses were doubled weekly until the 18th week in order to achieve an intake of 200 ml in about 4 months. RESULTS: 10 children received CM and 3 children received soy formula. Oral Tolerance Induction can be achieved by means of weekly administration of CM on 7 children. However in 2 children (20%) this therapeutic approach failed. and 1(10%) patient could take only limited amount f milk: 64 ml. CONCLUSIONS: We have found that specific oral tolerance induction (SOTI) should be a goal for treatment in children with IgE mediated CM Allergy.
J ALLERGY CLIN IMMUNOL FEBRUARY 2009
110
Comparative Study Of Food Allergy In Rural And Urban Chinese School Children G. W. Wong1, Y. Ma2, Y. Chan2, J. Fang3, Y. Li4, Y. Pan5, T. F. Leung1, F. Liu1; 1Chinese University of Hong Kong, Hong Kong, Hong Kong, 2Capital Institute of Pediatrics, Beijing, China, 3Institute for Environmental Hygiene, Beijing, China, 4Sun Yi Center of Disease Control, Beijing, China, 5Dongcheng School Health Care Institute, Beijing, China. RATIONALE: Epidemiological studies have suggested that the prevalence food allergies is on the rise. Research studies also suggested that the rural environment is associated with lower prevalence of asthma. The aim of the current study is to compare the prevalence of self reported food allergies and respiratory symptoms in urban and rural Chinese children. METHODS: Random samples of primary schoolchildren were recruited from Hong Kong, Beijing city and rural Beijing. Parents were asked to complete the validated Chinese version of the ISAAC core questionnaire and the Europrevall Screening questionnaire. RESULTS: A total of 16866 children (Hong Kong 6194, urban Beijing 5948, and rural Beijing 4724) agreed to enroll in the study (participation rate, 87%). The prevalence of self reported food allergies was highest in Hong Kong with 3.9% of children reported to have more than 4 episodes of adverse reaction to foods as compared to 2.0% (P < 0.01) in urban Beijing and 0.9% (P < 0.001) in rural Beijing. The most common reported food allergens in Hong Kong were shrimp (2.2%), egg (0.8%), and mango (0.7%). The prevalence of asthma diagnosis and wheeze ever was highest in Hong Kong (27%) as compared to that in urban Beijing (6%, P < 0.001), and rural Beijing (2.5%, P < 0.001). CONCLUSIONS: This study documented a lower prevalence of self-reported food allergies in rural setting as compared to the urban setting. There is also a strong relationship of asthma diagnosis and self reported food allergies. Further validation studies using skin-prick test and measurement of serum specific IgE are underway to confirm the findings of the current study.
111
Sesame Food Allergy and Sensitization in Children: A Growing Concern in the USA A. Alexis, B. Safier, D. W. Rosenthal, M. A. Cavuoto; Schneider Children’s Hospital, Long Island Jewish Hospital-North Shore University Medical Center, Great Neck, NY. RATIONALE: Sesame allergy has been described as a common food allergen affecting both children and adults mostly in Europe, Canada, Australia and Asia (Israel, Japan). Yet, there is limited data describing sesame allergy in the USA. METHODS: We conducted a retrospective chart review of patients from our Allergy Clinic that had CAP-RAST Class 2 to sesame (f10) and either a strong clinical history of an adverse reaction to sesame or atopic dermatitis. Charts were screened for gender, age at presentation, clinical presentation, CAP-RAST to f10 IgE, concurrent food allergies, history of atopy, and family history of atopy. RESULTS: Seventeen patients (35% Male) were identified. The mean age at first presentation was 6.9 6 11.1 years (range 8 months-44 years). The patients presented with a strong clinical history of an IgE-medicated reaction after the ingestion of sesame (13/17) or a history of atopic dermatitis (4/17). The most common presentation of the patients with a clinical history (13/17) was urticaria (46%), followed by angioedema (31%), gastrointestinal (15%) and respiratory (8%) manifestations. Of these patients 94% had a strong family history of atopy, 70% were also diagnosed with tree nut allergy, 65% with peanut allergy, 50% with asthma, and 30% with allergic rhinitis. CONCLUSIONS: Sesame allergy can cause severe IgE-mediated reactions and its prevalence is increasing worldwide. In our study we present seventeen patients with sesame allergy and characterize their presentation. Unlike peanut allergy there is little awareness of this allergen in the USA. It is imperative to educate patients, parents as well as providers about the risks associated with sesame allergy in the USA.