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Supplemental Foods and Tolerance to Peanut Allergen by Race
S108 Abstracts
407
SUNDAY
Supplemental Foods and Tolerance to Peanut Allergen by Race C. L. M. Joseph1, D. R. Ownby2, S. L. Havstad1, G. R. Wegienka1, E. M. Zoratti1, C. C. Johnson1; 1Henry Ford Hospital, Detroit, MI, 2Medical College of Georgia, Augusta, GA. RATIONALE: Age at exposure to supplementary food may confer protection (tolerance) or detriment (allergy). The relationship may differ for specific allergens, such as peanut, capable of causing severe reactions. We explored the relationship between introduction of supplementary foods before age 4 months (SF < 4 months) and IgE to peanut allergen (P-IgE) at 2 years using the racially diverse WHEALS birth cohort. METHODS: Maternal interviews at 1, 6, and 12 months included questions on age at introduction of food supplementary to breast feeding or formula, specifically asking about peanuts. At infant age 2 years, blood samples were collected to assess IgE. P-IgE was defined as IgE to peanut 0.35 IU/ml or greater. RESULTS: 249 maternal-infant pairs have data sufficient for analysis. 49% of mothers are African-American (AA); mean age 5 30.0 years. 30.9% of mothers reported SF < 4 months. Cumulative incidence of PIgE at 2 years was 10.8%. In bivariate analysis, Odds Ratio (OR) and 95% Confidence Interval (95%CI) for SF < 4 months and P-IgE was 0.4 (0.1-1.1), p 5 0.06. When stratified by race, the protective relationship between SF < 4months and P-IgE was significant for AA, OR 5 0.2 (0.1-1.0), p 5 0.04, but not for Non-AA infants, OR 5 0.7 (0.1-3.6), p 5 0.67. Multivariable analysis (or stratified analyses when cell sizes were small) did not significantly change results. CONCLUSIONS: SF < 4 months seems protective for peanut allergy by age 2 years, especially for AA infants.
408
Hymenoptera Sting Allergy in Irish School Children A. Jennings1, E. Duggan1, Y. Graif2, I. J. Perry1, J. O. Houri1 1 hane ; University College Cork, Cork, Ireland, 2Pulmonary Institute, Rabin Medical centre, Petah Tiqva, Israel. RATIONALE: To generate the first epidemiological data regarding the prevalence of hymenoptera allergy among school children in Ireland. METHODS: Questionnaires including a set of 6 sting-specific questions (Graif, JACI 2006) were distributed to the parents of primary school children aged 6-8 years and 11-13 years, divided equally between rural and urban backgrounds. RESULTS: 4,112 questionnaires were returned from 110 schools. 1,544 (37.5%) children had been stung in their lifetime. 5.8% of children stung experienced a large local reaction (LLR), 3.4% had a mild (cutaneous) systemic reaction (MSR) and 0.8% experienced a moderate/severe systemic reaction (SSR); these figures respectively represent 2.2%, 1.3% and 0.2% of the total study group. On logistic regression analysis older children and rural children were at a higher risk of being stung (OR 1.7; 95% CI 1.4 2.; OR 1.6;95% CI 1.4-1.8, respectively).Rural dwellers and asthma sufferers were more likely to experience an SSR (OR 4.3; 95% CI 1.4 13.5 and OR 2.8; 95% CI 1.8 - 4.3, respectively). 5.4% of the children with an LLR attended hospital compared with 5.5% of those with an MSR and 15.4% with an SSR. CONCLUSIONS: Hymenoptera stings are more common in rural than urban dwelling Irish children. Asthma imparted a greater risk of SSR in this study population. Severe reactions are unusual overall, occurring in less than 1% of those stung, a lower prevalence than in Israel but in keeping with other European reports.
J ALLERGY CLIN IMMUNOL FEBRUARY 2009
409
Exploring Risk Factors for Food Sensitization in a Racially Diverse Birth Cohort C. C. Johnson1, C. L. M. Joseph1, D. R. Ownby2, S. L. Havstad1, G. R. Wegienka1, E. M. Zoratti1; 1Henry Ford Hospital, Detroit, MI, 2Medical College of Georgia, Augusta, GA. RATIONALE: Factors related to food sensitization have not been extensively explored in diverse birth cohorts. Breastfeeding, early exposure to supplementary food (SF < 4months), and African-American (AA) race are potential risk factors for food sensitization. We explored the association of these factors to egg, milk, and peanut sensitization at 2 years using the WHEALS birth cohort. METHODS: Mothers were interviewed at 1, 6, and 12 months about infant feeding and age at exposure to foods supplementary to breastfeeding and formula. Blood samples were collected at infant age 2 years to measure IgE. Food sensitization (food-IgE) was defined as serum IgE for milk, egg, or peanut 0.35 UL/ml or greater. RESULTS: 249 maternal-infant pairs were included in this analysis. Mean age of cohort mothers was 30.0 years and 49% were AA. Prevalence of any food-IgE was 35.7%, 30.9% of mothers reported SF6months. In bivariate analyses, SF < 4months and breastfeeding were not related to food IgE, but the Relative Risk (95% Confidence Interval) for AA race and food-IgE was 1.4 (1.0-1.9), and was 1.6 (1.0-2.7) for egg, p 5 0.03; 1.6 (1.0-2.4) for milk, p 5 0.04 and 2.0 (1.0-4.3) for peanut, p 5 0.06. In multivariable analysis, only AA race was significantly related to food IgE (p 5 0.01). CONCLUSIONS: In this study population, AA race was the only variable related to food-IgE at 2 years.
410
Prevalence and Environmental Predictors of Food Allergy in Infants K. J. Allen1,2, J. Koplin2,3, L. Gurrin4, M. Gibson2, L. Thiele2, L. Miles2, K. Aurich2, D. Hill2, A. Lowe4, M. Matheson4, A. Ponsonby2, M. Tang1, S. Dhamage4, M. Wake2, N. Osborne2,4; 1Department of Allergy and Immunology, Royal Children’s Hospital, Melbourne, Australia, 2Murdoch Childrens Research Institute, Melbourne, Australia, 3Department of Paediatrics, The University of Melbourne, Melbourne, Australia, 4The Centre for Molecular, Environment, Genetic and Analytic (MEGA) Epidemiology, School of Population Health, The University of Melbourne, Melbourne, Australia. RATIONALE: We aim to measure the prevalence, and environmental and genetic risk factors for the development of food allergy in 12 month old infants prior to ingestion of peanuts. METHODS: 5000 participants will be recruited at immunisation clinics over 2.5 years. Parental questionnaires assessed potential environmental risk factors and were administered prior to knowledge of infant’s sensitisation status. Skin prick tests were performed for egg white, peanut, sesame and shrimp. Participants found to have any sensitisation (i.e. wheal > 5 1 mm) were formally assessed by inpatient oral food challenge. RESULTS: 310/419 approached (73% response rate) agreed to participate and 295 undertook SPT. There were no significant difference between nonsensitised and sensitised infants for birth weights (3416.8 6 SD582.9 versus 3455.1 6 SD460.2), not initially breast fed (10.5% versus 2.5%), LUSCS (32.9% versus 31.7%) but there was a difference between those still breast fed at 12 month (25.3% versus 38.7%). Rates of sensitisation (wheal > 5 3 mm) differed between egg (17.1%), peanut (6.2%), sesame (1.4%) and shellfish (0.4%). Of those with SPT > 5 3 mm, 87% attended food challenge clinics. Of the 13% who did not attend the follow up clinic, 40% were already tolerating the food in their diet. Based on negative challenge or history of intake, rates of allergy to egg were 7.1%, peanut 3.2%, and sesame <1%. Only one of 31 (3%) with SPT of 1 or 2 mm reacted to the food challenge. CONCLUSIONS: High rates of food sensitisation and allergy have been found in a cohort recruited from the general population in Australia.
407
SUNDAY
Supplemental Foods and Tolerance to Peanut Allergen by Race C. L. M. Joseph1, D. R. Ownby2, S. L. Havstad1, G. R. Wegienka1, E. M. Zoratti1, C. C. Johnson1; 1Henry Ford Hospital, Detroit, MI, 2Medical College of Georgia, Augusta, GA. RATIONALE: Age at exposure to supplementary food may confer protection (tolerance) or detriment (allergy). The relationship may differ for specific allergens, such as peanut, capable of causing severe reactions. We explored the relationship between introduction of supplementary foods before age 4 months (SF < 4 months) and IgE to peanut allergen (P-IgE) at 2 years using the racially diverse WHEALS birth cohort. METHODS: Maternal interviews at 1, 6, and 12 months included questions on age at introduction of food supplementary to breast feeding or formula, specifically asking about peanuts. At infant age 2 years, blood samples were collected to assess IgE. P-IgE was defined as IgE to peanut 0.35 IU/ml or greater. RESULTS: 249 maternal-infant pairs have data sufficient for analysis. 49% of mothers are African-American (AA); mean age 5 30.0 years. 30.9% of mothers reported SF < 4 months. Cumulative incidence of PIgE at 2 years was 10.8%. In bivariate analysis, Odds Ratio (OR) and 95% Confidence Interval (95%CI) for SF < 4 months and P-IgE was 0.4 (0.1-1.1), p 5 0.06. When stratified by race, the protective relationship between SF < 4months and P-IgE was significant for AA, OR 5 0.2 (0.1-1.0), p 5 0.04, but not for Non-AA infants, OR 5 0.7 (0.1-3.6), p 5 0.67. Multivariable analysis (or stratified analyses when cell sizes were small) did not significantly change results. CONCLUSIONS: SF < 4 months seems protective for peanut allergy by age 2 years, especially for AA infants.
408
Hymenoptera Sting Allergy in Irish School Children A. Jennings1, E. Duggan1, Y. Graif2, I. J. Perry1, J. O. Houri1 1 hane ; University College Cork, Cork, Ireland, 2Pulmonary Institute, Rabin Medical centre, Petah Tiqva, Israel. RATIONALE: To generate the first epidemiological data regarding the prevalence of hymenoptera allergy among school children in Ireland. METHODS: Questionnaires including a set of 6 sting-specific questions (Graif, JACI 2006) were distributed to the parents of primary school children aged 6-8 years and 11-13 years, divided equally between rural and urban backgrounds. RESULTS: 4,112 questionnaires were returned from 110 schools. 1,544 (37.5%) children had been stung in their lifetime. 5.8% of children stung experienced a large local reaction (LLR), 3.4% had a mild (cutaneous) systemic reaction (MSR) and 0.8% experienced a moderate/severe systemic reaction (SSR); these figures respectively represent 2.2%, 1.3% and 0.2% of the total study group. On logistic regression analysis older children and rural children were at a higher risk of being stung (OR 1.7; 95% CI 1.4 2.; OR 1.6;95% CI 1.4-1.8, respectively).Rural dwellers and asthma sufferers were more likely to experience an SSR (OR 4.3; 95% CI 1.4 13.5 and OR 2.8; 95% CI 1.8 - 4.3, respectively). 5.4% of the children with an LLR attended hospital compared with 5.5% of those with an MSR and 15.4% with an SSR. CONCLUSIONS: Hymenoptera stings are more common in rural than urban dwelling Irish children. Asthma imparted a greater risk of SSR in this study population. Severe reactions are unusual overall, occurring in less than 1% of those stung, a lower prevalence than in Israel but in keeping with other European reports.
J ALLERGY CLIN IMMUNOL FEBRUARY 2009
409
Exploring Risk Factors for Food Sensitization in a Racially Diverse Birth Cohort C. C. Johnson1, C. L. M. Joseph1, D. R. Ownby2, S. L. Havstad1, G. R. Wegienka1, E. M. Zoratti1; 1Henry Ford Hospital, Detroit, MI, 2Medical College of Georgia, Augusta, GA. RATIONALE: Factors related to food sensitization have not been extensively explored in diverse birth cohorts. Breastfeeding, early exposure to supplementary food (SF < 4months), and African-American (AA) race are potential risk factors for food sensitization. We explored the association of these factors to egg, milk, and peanut sensitization at 2 years using the WHEALS birth cohort. METHODS: Mothers were interviewed at 1, 6, and 12 months about infant feeding and age at exposure to foods supplementary to breastfeeding and formula. Blood samples were collected at infant age 2 years to measure IgE. Food sensitization (food-IgE) was defined as serum IgE for milk, egg, or peanut 0.35 UL/ml or greater. RESULTS: 249 maternal-infant pairs were included in this analysis. Mean age of cohort mothers was 30.0 years and 49% were AA. Prevalence of any food-IgE was 35.7%, 30.9% of mothers reported SF6months. In bivariate analyses, SF < 4months and breastfeeding were not related to food IgE, but the Relative Risk (95% Confidence Interval) for AA race and food-IgE was 1.4 (1.0-1.9), and was 1.6 (1.0-2.7) for egg, p 5 0.03; 1.6 (1.0-2.4) for milk, p 5 0.04 and 2.0 (1.0-4.3) for peanut, p 5 0.06. In multivariable analysis, only AA race was significantly related to food IgE (p 5 0.01). CONCLUSIONS: In this study population, AA race was the only variable related to food-IgE at 2 years.
410
Prevalence and Environmental Predictors of Food Allergy in Infants K. J. Allen1,2, J. Koplin2,3, L. Gurrin4, M. Gibson2, L. Thiele2, L. Miles2, K. Aurich2, D. Hill2, A. Lowe4, M. Matheson4, A. Ponsonby2, M. Tang1, S. Dhamage4, M. Wake2, N. Osborne2,4; 1Department of Allergy and Immunology, Royal Children’s Hospital, Melbourne, Australia, 2Murdoch Childrens Research Institute, Melbourne, Australia, 3Department of Paediatrics, The University of Melbourne, Melbourne, Australia, 4The Centre for Molecular, Environment, Genetic and Analytic (MEGA) Epidemiology, School of Population Health, The University of Melbourne, Melbourne, Australia. RATIONALE: We aim to measure the prevalence, and environmental and genetic risk factors for the development of food allergy in 12 month old infants prior to ingestion of peanuts. METHODS: 5000 participants will be recruited at immunisation clinics over 2.5 years. Parental questionnaires assessed potential environmental risk factors and were administered prior to knowledge of infant’s sensitisation status. Skin prick tests were performed for egg white, peanut, sesame and shrimp. Participants found to have any sensitisation (i.e. wheal > 5 1 mm) were formally assessed by inpatient oral food challenge. RESULTS: 310/419 approached (73% response rate) agreed to participate and 295 undertook SPT. There were no significant difference between nonsensitised and sensitised infants for birth weights (3416.8 6 SD582.9 versus 3455.1 6 SD460.2), not initially breast fed (10.5% versus 2.5%), LUSCS (32.9% versus 31.7%) but there was a difference between those still breast fed at 12 month (25.3% versus 38.7%). Rates of sensitisation (wheal > 5 3 mm) differed between egg (17.1%), peanut (6.2%), sesame (1.4%) and shellfish (0.4%). Of those with SPT > 5 3 mm, 87% attended food challenge clinics. Of the 13% who did not attend the follow up clinic, 40% were already tolerating the food in their diet. Based on negative challenge or history of intake, rates of allergy to egg were 7.1%, peanut 3.2%, and sesame <1%. Only one of 31 (3%) with SPT of 1 or 2 mm reacted to the food challenge. CONCLUSIONS: High rates of food sensitisation and allergy have been found in a cohort recruited from the general population in Australia.