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The Natural History of Egg Allergy
Abstracts S115
J ALLERGY CLIN IMMUNOL VOLUME 119, NUMBER 1
Children with Multiple Food Allergies are Not More Likely to be Underweight than Other Children J. L. P. Protudjer, J. J. Liem, A. L. Kozyrskyj, A. B. Becker; University of Manitoba, Winnipeg, MB, CANADA. RATIONALE: Data suggest that children with multiple food allergies (FA) are more likely to be underweight than children with one or no food allergies because they/their parents closely monitor food choices. METHODS: 479 children born in Manitoba in 1995 were enrolled in a case-control cohort study. Based on parental report, the cohort included children with asthma (40%), children with allergy (20%) and children with neither asthma nor allergy. In 2005/6, parents completed questionnaires that queried FA in their children. We measured children’s weights and heights. RESULTS: 403 (84.13%) had no FA, 46 (9.60%) had 1 FA and 30 (6.26%) had 2 FA. Normal weight was defined as BMI > 15th %ile and <85th %ile. Overweight was defined as BMI 85th %ile. 271 (56.6%) were normal weight, 38 (7.9%) were underweight and 155 (32.4%) were overweight. There was no difference in prevalence of underweight (p<0.31) or overweight (p<0.92) when dichotomizing FA versus no FA. There is no difference in prevalence of overweight in children with 1 or 2 FA (p<0.92). However, children with 1 FA are significantly more likely to be underweight (p<0.01 OR 0.23 95% CI 0.07 - 0.78) than children with multiple FA. CONCLUSIONS: Contrary to our hypothesis and a limited number of other studies, children with no FA or those with only 1 FA are significantly more likely to be underweight than children with multiple FA. This may be due to selection bias. These data warrant further investigation into the relationship of weight and nutrition in larger pediatric populations. Funding: AllerGen, Manitoba Institute of Child Health, National Training Program in Allergy and Asthma
453
The Natural History of Egg Allergy J. H. Rabe, E. C. Matsui, K. E. Mudd, J. M. Skripak, R. A. Wood; Johns Hopkins Hospital, Baltimore, MD. RATIONALE: To describe the natural history of egg allergy and to identify predictors of oral tolerance/outgrowing egg allergy. METHODS: The records of egg allergic patients seen in a tertiary referral clinic were reviewed. Data collected included egg allergy related symptoms, history of other food allergies and atopic diseases, skin tests, eggspecific IgE levels (e-IgE), and food challenge results. RESULTS: 163 patients were studied: 110 male and 53 female. 157 (96%) had at least one other food allergy. 101 (62%) had reactive airway disease, 108 (66%) had allergic rhinitis, and 131 (80%) had atopic dermatitis. The median age at initial visit was 2.6 years; the median duration of follow-up was 3.3 years (range 0-15.8 years). Overall, 82 (50%) patients outgrew their egg allergy by the final visit. Of the 82 who outgrew egg allergy, 37 (45%) did so by age 5. Among those who outgrew egg allergy, e-IgE levels tended to peak at age 1 and decrease over time. Median e-IgE levels were significantly higher at all ages in patients with persistent versus outgrown egg allergy (eg. 7.4 vs 1.8 kU/L, p<0.001 at 2 years; 3.4 vs 1.8 kU/L, p<0.05 at 6 years) as was the median peak e-IgE (9.8 vs 1.7 kU/L, p<0.0001). CONCLUSIONS: In this referral population, 50% of children with egg allergy outgrew their allergy by age 17. Absolute e-IgE levels and their trends over time were useful predictors of outgrowing egg allergy.
454
Identification of a MnSOD-like Protein as a New Major Pistachio Allergen R. Ayuso, G. Grishina, K. Ahn, L. Bardina, K. Beyer, H. Sampson; Mt Sinai Medical Center, New York, NY. RATIONALE: Among tree nuts, Pistachio is frequently responsible for food-induced allergic reactions in allergic individuals. Pistachio (Pistacia vera) belongs to the Anacardiacea family, which also includes mango and cashew. In contrast to other tree nuts, little is know about the allergenic proteins in pistachio. AIM: Identify and characterize new pistachio allergens. METHODS: 1D- and 2D-electrophoresis followed by immunoblotting for IgE detection were done using sera from 27 well-characterized pistachioallergic subjects. Each patient had history of an immediate allergic reaction following ingestion of pistachio and pistachio-specific IgE by CAP-RAST. Protein identification was done from a database using LC-MS/MS (nanocapillary HPLC ion trap mass spectrometry) of 2D in-gel tryptic digest. RESULTS: Immunolabeling of 1D and 2D membranes demonstrated IgEbinding to a 23 kD pistachio protein by 16 out of 27 sera (59%). 2D electrophoresis revealed that this protein had an isoelectric point of 6. Tryptic digestion of the 23 kD band followed by LC-MS/MS analysis of the peptides showed high homology with sequences present in Hevea braziliensis (latex) IgE-binding MnSOD (manganese superoxide dismutase), indicating that this 23 kD pistachio protein is a new allergenic MnSOD-like molecule. CONCLUSIONS: A MnSOD-like protein appears to be a novel major pistachio allergen, which may be responsible for IgE cross-reactivity with latex. Funding: Segal Family
455
Immunochemical and Biological Methods for Estimation of Allergen Content Used for Soy Allergy Risk Assessments of Biotechnologically Derived Products M. H. Pedersen1, P. S. Skov1, T. Holzhauser2, C. Bindslev-Jensen3, D. S. Brinch4, L. K. Poulsen1; 1National university hospital of Denmark, Copenhagen, DENMARK, 2Paul-Ehrlich-Institut, Langen, GERMANY, 3 Odense university hospital, Odense, DENMARK, 4Novozymes A/S, Bagsværd, DENMARK. RATIONALE: Heat-sterilized soybean is widely used as nitrogen source in production of proteins made by fermentation by microorganisms. Some of these are enzymes used as processing aids in human foods. METHODS: Five soy detection methods were used: 1. Sandwich-ELISA based on polyclonal rabbit antibodies (abs) to native soy, 2. Commercial ELISA kit (Tepnel Biosystems) based on abs to denatured, refolded protein, 3. Competitive ELISA based on a commercial rabbit anti soy (Sigma) also to denatured, refolded protein, 4. Enzyme-AllergoSorbentTest (EAST) Inhibition based on a serum from a soy allergic patient and 5. Histamine Release (HR) using passively sensitized basophils with the same serum. Samples were taken of soybean being sterilized at 25, 50, 75, 100 and 1308C (t 5 10, 30, 60 and 90 minutes). Moreover, 21 commercial enzyme products obtained from fermentation of soybeans were tested for soy residue in assays 1 and 3. RESULTS: Almost no soy was detected by the sandwich ELISA in the sample taken after 90 min of sterilization. About 86% of the initial amount of soy before autoclaving had disappeared when tested in the commercial kit, and the competitive ELISA, and approximately 90% of the allergenicity of soy had disappeared according to results obtained from HR. Twentyone enzymes tested negative for soy in the sandwich ELISA and the competitive ELISA, showing that soy is either consumed during fermentation or removed by down-stream purification. CONCLUSIONS: More than a single method should be used for allergen testing. No safety concerns were identified with regard to soy in these enzymes. Funding: Novozymes A/S
SUNDAY
452
J ALLERGY CLIN IMMUNOL VOLUME 119, NUMBER 1
Children with Multiple Food Allergies are Not More Likely to be Underweight than Other Children J. L. P. Protudjer, J. J. Liem, A. L. Kozyrskyj, A. B. Becker; University of Manitoba, Winnipeg, MB, CANADA. RATIONALE: Data suggest that children with multiple food allergies (FA) are more likely to be underweight than children with one or no food allergies because they/their parents closely monitor food choices. METHODS: 479 children born in Manitoba in 1995 were enrolled in a case-control cohort study. Based on parental report, the cohort included children with asthma (40%), children with allergy (20%) and children with neither asthma nor allergy. In 2005/6, parents completed questionnaires that queried FA in their children. We measured children’s weights and heights. RESULTS: 403 (84.13%) had no FA, 46 (9.60%) had 1 FA and 30 (6.26%) had 2 FA. Normal weight was defined as BMI > 15th %ile and <85th %ile. Overweight was defined as BMI 85th %ile. 271 (56.6%) were normal weight, 38 (7.9%) were underweight and 155 (32.4%) were overweight. There was no difference in prevalence of underweight (p<0.31) or overweight (p<0.92) when dichotomizing FA versus no FA. There is no difference in prevalence of overweight in children with 1 or 2 FA (p<0.92). However, children with 1 FA are significantly more likely to be underweight (p<0.01 OR 0.23 95% CI 0.07 - 0.78) than children with multiple FA. CONCLUSIONS: Contrary to our hypothesis and a limited number of other studies, children with no FA or those with only 1 FA are significantly more likely to be underweight than children with multiple FA. This may be due to selection bias. These data warrant further investigation into the relationship of weight and nutrition in larger pediatric populations. Funding: AllerGen, Manitoba Institute of Child Health, National Training Program in Allergy and Asthma
453
The Natural History of Egg Allergy J. H. Rabe, E. C. Matsui, K. E. Mudd, J. M. Skripak, R. A. Wood; Johns Hopkins Hospital, Baltimore, MD. RATIONALE: To describe the natural history of egg allergy and to identify predictors of oral tolerance/outgrowing egg allergy. METHODS: The records of egg allergic patients seen in a tertiary referral clinic were reviewed. Data collected included egg allergy related symptoms, history of other food allergies and atopic diseases, skin tests, eggspecific IgE levels (e-IgE), and food challenge results. RESULTS: 163 patients were studied: 110 male and 53 female. 157 (96%) had at least one other food allergy. 101 (62%) had reactive airway disease, 108 (66%) had allergic rhinitis, and 131 (80%) had atopic dermatitis. The median age at initial visit was 2.6 years; the median duration of follow-up was 3.3 years (range 0-15.8 years). Overall, 82 (50%) patients outgrew their egg allergy by the final visit. Of the 82 who outgrew egg allergy, 37 (45%) did so by age 5. Among those who outgrew egg allergy, e-IgE levels tended to peak at age 1 and decrease over time. Median e-IgE levels were significantly higher at all ages in patients with persistent versus outgrown egg allergy (eg. 7.4 vs 1.8 kU/L, p<0.001 at 2 years; 3.4 vs 1.8 kU/L, p<0.05 at 6 years) as was the median peak e-IgE (9.8 vs 1.7 kU/L, p<0.0001). CONCLUSIONS: In this referral population, 50% of children with egg allergy outgrew their allergy by age 17. Absolute e-IgE levels and their trends over time were useful predictors of outgrowing egg allergy.
454
Identification of a MnSOD-like Protein as a New Major Pistachio Allergen R. Ayuso, G. Grishina, K. Ahn, L. Bardina, K. Beyer, H. Sampson; Mt Sinai Medical Center, New York, NY. RATIONALE: Among tree nuts, Pistachio is frequently responsible for food-induced allergic reactions in allergic individuals. Pistachio (Pistacia vera) belongs to the Anacardiacea family, which also includes mango and cashew. In contrast to other tree nuts, little is know about the allergenic proteins in pistachio. AIM: Identify and characterize new pistachio allergens. METHODS: 1D- and 2D-electrophoresis followed by immunoblotting for IgE detection were done using sera from 27 well-characterized pistachioallergic subjects. Each patient had history of an immediate allergic reaction following ingestion of pistachio and pistachio-specific IgE by CAP-RAST. Protein identification was done from a database using LC-MS/MS (nanocapillary HPLC ion trap mass spectrometry) of 2D in-gel tryptic digest. RESULTS: Immunolabeling of 1D and 2D membranes demonstrated IgEbinding to a 23 kD pistachio protein by 16 out of 27 sera (59%). 2D electrophoresis revealed that this protein had an isoelectric point of 6. Tryptic digestion of the 23 kD band followed by LC-MS/MS analysis of the peptides showed high homology with sequences present in Hevea braziliensis (latex) IgE-binding MnSOD (manganese superoxide dismutase), indicating that this 23 kD pistachio protein is a new allergenic MnSOD-like molecule. CONCLUSIONS: A MnSOD-like protein appears to be a novel major pistachio allergen, which may be responsible for IgE cross-reactivity with latex. Funding: Segal Family
455
Immunochemical and Biological Methods for Estimation of Allergen Content Used for Soy Allergy Risk Assessments of Biotechnologically Derived Products M. H. Pedersen1, P. S. Skov1, T. Holzhauser2, C. Bindslev-Jensen3, D. S. Brinch4, L. K. Poulsen1; 1National university hospital of Denmark, Copenhagen, DENMARK, 2Paul-Ehrlich-Institut, Langen, GERMANY, 3 Odense university hospital, Odense, DENMARK, 4Novozymes A/S, Bagsværd, DENMARK. RATIONALE: Heat-sterilized soybean is widely used as nitrogen source in production of proteins made by fermentation by microorganisms. Some of these are enzymes used as processing aids in human foods. METHODS: Five soy detection methods were used: 1. Sandwich-ELISA based on polyclonal rabbit antibodies (abs) to native soy, 2. Commercial ELISA kit (Tepnel Biosystems) based on abs to denatured, refolded protein, 3. Competitive ELISA based on a commercial rabbit anti soy (Sigma) also to denatured, refolded protein, 4. Enzyme-AllergoSorbentTest (EAST) Inhibition based on a serum from a soy allergic patient and 5. Histamine Release (HR) using passively sensitized basophils with the same serum. Samples were taken of soybean being sterilized at 25, 50, 75, 100 and 1308C (t 5 10, 30, 60 and 90 minutes). Moreover, 21 commercial enzyme products obtained from fermentation of soybeans were tested for soy residue in assays 1 and 3. RESULTS: Almost no soy was detected by the sandwich ELISA in the sample taken after 90 min of sterilization. About 86% of the initial amount of soy before autoclaving had disappeared when tested in the commercial kit, and the competitive ELISA, and approximately 90% of the allergenicity of soy had disappeared according to results obtained from HR. Twentyone enzymes tested negative for soy in the sandwich ELISA and the competitive ELISA, showing that soy is either consumed during fermentation or removed by down-stream purification. CONCLUSIONS: More than a single method should be used for allergen testing. No safety concerns were identified with regard to soy in these enzymes. Funding: Novozymes A/S
SUNDAY
452