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Continuing Avoidance Diets after Negative Food Challenges
S44 Abstracts
SATURDAY
Risk-taking and Coping Strategies of Food Allergic Adolescents and Young Adults M. Sampson1, A. Munoz-Furlong2, S. H. Sicherer1; 1Pediatrics, Mt Sinai School Of Medicine, New York, NY, 2Food Allergy & Anaphylaxis Network, Fairfax, VA. RATIONALE: To identify factors to explain why adolescents and young adults are at high risk for fatal food anaphylaxis. METHODS: Web-based questionnaire based upon focus groups. RESULTS: Participants (174 subjects; 49% male) were 13-21 yrs of age (mean, 16 yrs) and reported: peanut allergy (75%), milk allergy (20%), >2 food allergies (75%), anaphylaxis (82%) and >3 lifetime reactions (52%). Regarding risk-taking, 74% report always carrying epinephrine, but frequencies varied during certain activities: traveling (94%), restaurants (81%), friends’ homes (67%), school dance (61%), wearing tight clothes (53%) and sports (43%). While 75% “always” read labels, 42% would eat a food labeled “may contain” an allergen. We designated 29 participants as “High Risk” (HR) because they do not always carry epinephrine and ate foods that “may contain” allergens. The HR group, compared to the rest of the group (p<.05), was less concerned with their allergy, less likely to consider “may contain” labels a risk, had more recent reactions, and felt “different” because of their allergy. The HR group was not distinguishable (p=ns) by age, gender, number of lifetime reactions, or severity of symptoms. Teens variably (60%) tell their friends about their allergy and 68% feel education of their friends would make living with food allergy easier. CONCLUSIONS: A sizeable number of food-allergic teens admit to risk-taking that varies by social circumstances and perceived risks. The results imply that educations of teens, and importantly those around them during social activities, may reduce risk-taking and its consequences. Funding: Food Allergy & Anaphylaxis Network, Food Allergy Initiative
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Continuing Avoidance Diets after Negative Food Challenges
P. A. Eigenmann, J. C. Caubet, S. A. Zamora; Children’s University Hospital, Geneva, SWITZERLAND. RATIONALE: Patients with a negative food challenge do not always reintroduce the food at home after the challenge. This study aimed to evaluate why the food is not later eaten, and which families have to be convinced that the food is safe. METHODS: Patients/families with a negative food challenge between 1999 and 2003 were contacted my mail and were invited to fill out a questionnaire comprising items on the reaction at diagnosis, the fear of an accidental reaction, and the consumption of the food after the negative food challenge. Informed consent was obtained, and the study was approved by the IRB. RESULTS: A total of 74 questionnaires from 55 patients were collected. Mostly egg and milk (21 each), and peanuts (13) were tested negative. The food was not reintroduced into the patient’s diet after one third of the negative challenges. Ten patients reported allergic symptoms, but investigation of the reported reactions suggested unspecific flares of atopic dermatitis or reactions suggestive of intolerance. The length of the eviction diet, the severity of the initial reaction, or the food tested did not influence the decision to reintroduce the food. CONCLUSIONS: Recent studies suggest, that patients should regularly eat the food tested negative in order to avoid reoccurrence of food allergy. In this study we did not identify a specific risk group, which avoids reintroduction. After a negative food challenge, the importance of reintroducing the food should be emphasized in all patients. IgE from Some Green Kiwifruit Allergic Individuals Binds to Proteins in Hardy Kiwifruit, a Third Cultivated Species of the Genus Actinidia R. E. Goodman1, L. Chen1, J. Lucas2, J. O. Hourihane2, S. L. Taylor1; 1Food Science & Technology, University of Nebraska, Lincoln, NE,
175
J ALLERGY CLIN IMMUNOL FEBRUARY 2006
2Allergy
and Inflammation Sciences, University of Southampton, Southampton, UNITED KINGDOM. RATIONALE: Since hardy kiwifruit (Acintinidia arguta) is now cultivated in western North America, we tested protein extracts of hardy, green (Actinidia deliciosa) and gold (Actinidia chinensis) kiwifruit for IgE binding using sera from individuals with clinically diagnosed food allergies to green kiwifruit, to evaluate potential cross-reactivity. METHODS: Sera from twelve green kiwifruit-allergic subjects (eight were positive by DBPCFC, four severe reactors were not challenged but had positive ImmunoCAP) and control subjects were assayed for IgE binding to soluble proteins in green, gold and hardy kiwifruits using reducing and non-reducing SDS-PAGE immunoblots and direct enzyme linked immunosorbent assays (ELISA). RESULTS: IgE-ELISA results of all kiwi-allergic subjects were positive compared to controls for one or more kiwifruit extracts. Immunoblot results demonstrated individual patient and species variability. Two sera with strong ELISA positive results to both hardy and green, but not gold kiwifruit did not show marked IgE binding to kiwifruit proteins on immunoblots with reduced, heat denatured extracts, but clearly bound two or more proteins from non-reduced, unheated extracts of hardy, but not green kiwifruit. One kiwifruit-allergic individual had marked binding to non-reduced, unheated gold kiwifruit proteins. Only one kiwifruit-allergic individual had marked binding to proteins of all species on the reduced gel blot. Some control sera showed marked IgE binding to high molecular weight proteins on immunblots. CONCLUSIONS: These results suggest some kiwifruit-allergic individuals may suffer allergic cross-reactions if they consume hardy kiwifruit. They also demonstrate the difficulty in developing in vitro reagents for accurate diagnosis of kiwifruit allergy and for correctly identifying major allergens. Funding: Efficas, Inc. Establishing a Milk Specific IgE Decision Point in IgE Mediated Cow’S Milk Allergy (CMA) Patients from a Tertiary Pediatric Brazilian Center A. K. F. Gushken, A. P. M. Castro, A. C. Pastorino, E. Ciccone, R. F. F. Gonçalves, C. M. A. Jacob; Department of Pediatrics, University of Sao Paulo, Sao Paulo, BRAZIL. RATIONALE: An optimal milk specific IgE decision point had been establish for CMA diagnosis but this cut off should be evaluated in different populations. METHODS: We evaluated 23 patients (14male, mean age 4y 2mo, ranging from 11mo to 14y) with cow milk IgE mediated allergy confirmed by anaphylaxis or positive double blind placebo controlled food challenge (DBPCFC) . All of them performed Pharmacia ImmunoCAP® system to milk IgE. A group of 23 equivalent healthy children was considered as control. Sensitivity (Se), specificity (Sp), PPV, NPV for all levels from 0,35 to 15 kU/L were determined. As the objective of this analysis was to consider the diagnosis and not only a screening test, PPV and NPV were the main valorized measures. RESULTS: Levels under 11kU/L did not show adequate PPV neither NPV. The best values were obtained with ImmunoCap levels from 11 to 13 kU/L (Se =78,2%, Sp= 100%, PPV = 100%, NPV= 82,1%). ImmunoCap level 14 showed : Se =69,5%, Sp= 100%, PPV = 100%, NPV= 76,6% and level 15 showed Se =65,2%, Sp= 100, PPV = 100%, NPV= 74,1%. CONCLUSIONS: In this study, the most adequate concentration of whole milk IgE was 11 suggesting that these levels vary from different population, but it is necessary more studies to evaluate these findings. Funding: University of Sao Paulo
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SATURDAY
Risk-taking and Coping Strategies of Food Allergic Adolescents and Young Adults M. Sampson1, A. Munoz-Furlong2, S. H. Sicherer1; 1Pediatrics, Mt Sinai School Of Medicine, New York, NY, 2Food Allergy & Anaphylaxis Network, Fairfax, VA. RATIONALE: To identify factors to explain why adolescents and young adults are at high risk for fatal food anaphylaxis. METHODS: Web-based questionnaire based upon focus groups. RESULTS: Participants (174 subjects; 49% male) were 13-21 yrs of age (mean, 16 yrs) and reported: peanut allergy (75%), milk allergy (20%), >2 food allergies (75%), anaphylaxis (82%) and >3 lifetime reactions (52%). Regarding risk-taking, 74% report always carrying epinephrine, but frequencies varied during certain activities: traveling (94%), restaurants (81%), friends’ homes (67%), school dance (61%), wearing tight clothes (53%) and sports (43%). While 75% “always” read labels, 42% would eat a food labeled “may contain” an allergen. We designated 29 participants as “High Risk” (HR) because they do not always carry epinephrine and ate foods that “may contain” allergens. The HR group, compared to the rest of the group (p<.05), was less concerned with their allergy, less likely to consider “may contain” labels a risk, had more recent reactions, and felt “different” because of their allergy. The HR group was not distinguishable (p=ns) by age, gender, number of lifetime reactions, or severity of symptoms. Teens variably (60%) tell their friends about their allergy and 68% feel education of their friends would make living with food allergy easier. CONCLUSIONS: A sizeable number of food-allergic teens admit to risk-taking that varies by social circumstances and perceived risks. The results imply that educations of teens, and importantly those around them during social activities, may reduce risk-taking and its consequences. Funding: Food Allergy & Anaphylaxis Network, Food Allergy Initiative
173
174
Continuing Avoidance Diets after Negative Food Challenges
P. A. Eigenmann, J. C. Caubet, S. A. Zamora; Children’s University Hospital, Geneva, SWITZERLAND. RATIONALE: Patients with a negative food challenge do not always reintroduce the food at home after the challenge. This study aimed to evaluate why the food is not later eaten, and which families have to be convinced that the food is safe. METHODS: Patients/families with a negative food challenge between 1999 and 2003 were contacted my mail and were invited to fill out a questionnaire comprising items on the reaction at diagnosis, the fear of an accidental reaction, and the consumption of the food after the negative food challenge. Informed consent was obtained, and the study was approved by the IRB. RESULTS: A total of 74 questionnaires from 55 patients were collected. Mostly egg and milk (21 each), and peanuts (13) were tested negative. The food was not reintroduced into the patient’s diet after one third of the negative challenges. Ten patients reported allergic symptoms, but investigation of the reported reactions suggested unspecific flares of atopic dermatitis or reactions suggestive of intolerance. The length of the eviction diet, the severity of the initial reaction, or the food tested did not influence the decision to reintroduce the food. CONCLUSIONS: Recent studies suggest, that patients should regularly eat the food tested negative in order to avoid reoccurrence of food allergy. In this study we did not identify a specific risk group, which avoids reintroduction. After a negative food challenge, the importance of reintroducing the food should be emphasized in all patients. IgE from Some Green Kiwifruit Allergic Individuals Binds to Proteins in Hardy Kiwifruit, a Third Cultivated Species of the Genus Actinidia R. E. Goodman1, L. Chen1, J. Lucas2, J. O. Hourihane2, S. L. Taylor1; 1Food Science & Technology, University of Nebraska, Lincoln, NE,
175
J ALLERGY CLIN IMMUNOL FEBRUARY 2006
2Allergy
and Inflammation Sciences, University of Southampton, Southampton, UNITED KINGDOM. RATIONALE: Since hardy kiwifruit (Acintinidia arguta) is now cultivated in western North America, we tested protein extracts of hardy, green (Actinidia deliciosa) and gold (Actinidia chinensis) kiwifruit for IgE binding using sera from individuals with clinically diagnosed food allergies to green kiwifruit, to evaluate potential cross-reactivity. METHODS: Sera from twelve green kiwifruit-allergic subjects (eight were positive by DBPCFC, four severe reactors were not challenged but had positive ImmunoCAP) and control subjects were assayed for IgE binding to soluble proteins in green, gold and hardy kiwifruits using reducing and non-reducing SDS-PAGE immunoblots and direct enzyme linked immunosorbent assays (ELISA). RESULTS: IgE-ELISA results of all kiwi-allergic subjects were positive compared to controls for one or more kiwifruit extracts. Immunoblot results demonstrated individual patient and species variability. Two sera with strong ELISA positive results to both hardy and green, but not gold kiwifruit did not show marked IgE binding to kiwifruit proteins on immunoblots with reduced, heat denatured extracts, but clearly bound two or more proteins from non-reduced, unheated extracts of hardy, but not green kiwifruit. One kiwifruit-allergic individual had marked binding to non-reduced, unheated gold kiwifruit proteins. Only one kiwifruit-allergic individual had marked binding to proteins of all species on the reduced gel blot. Some control sera showed marked IgE binding to high molecular weight proteins on immunblots. CONCLUSIONS: These results suggest some kiwifruit-allergic individuals may suffer allergic cross-reactions if they consume hardy kiwifruit. They also demonstrate the difficulty in developing in vitro reagents for accurate diagnosis of kiwifruit allergy and for correctly identifying major allergens. Funding: Efficas, Inc. Establishing a Milk Specific IgE Decision Point in IgE Mediated Cow’S Milk Allergy (CMA) Patients from a Tertiary Pediatric Brazilian Center A. K. F. Gushken, A. P. M. Castro, A. C. Pastorino, E. Ciccone, R. F. F. Gonçalves, C. M. A. Jacob; Department of Pediatrics, University of Sao Paulo, Sao Paulo, BRAZIL. RATIONALE: An optimal milk specific IgE decision point had been establish for CMA diagnosis but this cut off should be evaluated in different populations. METHODS: We evaluated 23 patients (14male, mean age 4y 2mo, ranging from 11mo to 14y) with cow milk IgE mediated allergy confirmed by anaphylaxis or positive double blind placebo controlled food challenge (DBPCFC) . All of them performed Pharmacia ImmunoCAP® system to milk IgE. A group of 23 equivalent healthy children was considered as control. Sensitivity (Se), specificity (Sp), PPV, NPV for all levels from 0,35 to 15 kU/L were determined. As the objective of this analysis was to consider the diagnosis and not only a screening test, PPV and NPV were the main valorized measures. RESULTS: Levels under 11kU/L did not show adequate PPV neither NPV. The best values were obtained with ImmunoCap levels from 11 to 13 kU/L (Se =78,2%, Sp= 100%, PPV = 100%, NPV= 82,1%). ImmunoCap level 14 showed : Se =69,5%, Sp= 100%, PPV = 100%, NPV= 76,6% and level 15 showed Se =65,2%, Sp= 100, PPV = 100%, NPV= 74,1%. CONCLUSIONS: In this study, the most adequate concentration of whole milk IgE was 11 suggesting that these levels vary from different population, but it is necessary more studies to evaluate these findings. Funding: University of Sao Paulo
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