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Wheat Protein Recognition Pattern in Thai Children with Wheat Allergy
AB130 Abstracts
412
J ALLERGY CLIN IMMUNOL FEBRUARY 2017
increase are warranted. Understanding the changes in peanut sensitization over time is a crucial step in determining likelihood of clinical reactivity.
Infant and Young Child Peanut Challenges, a Clinical Application of the Learning Early About Peanut Allergy Study 1
2
SUNDAY
Laura J. West, MD, PGY-3, Pediatrics Resident , Carolyn Baloh, MD , Hey Chong, MD, PhD1, Allyson S. Larkin, MD1, David R. Nash, MD1, John Broyles, CRNP1, Daniel G. Winger, MS3, Li Wang3, and Todd D. Green, MD4; 1Children’s Hospital of Pittsburgh of UPMC, Pittsburgh, PA, 2Duke Division of Allergy and Immunology, Durham, NC, 3University of Pittsburgh Clinical and Translational Science Institute, Pittsburgh, PA, 4Children’s Hospital of Pittsburgh of UPMC, Division of Pulmonary Medicine, Allergy and Immunology, Pittsburgh, PA. RATIONALE: The Learning Early About Peanut allergy (LEAP) and LEAP-On studies demonstrated decreased risk of peanut allergy with early peanut introduction in non-allergic, at-risk children. This retrospective chart review highlights a practical implementation of these findings. METHODS: Retrospective chart review of young children at risk for peanut allergy evaluated at Children’s Hospital of Pittsburgh of UPMC with a peanut food challenge between March 1, 2015 and July 31, 2016. Primary outcome was symptoms during challenge. Study was IRB exempt approved. RESULTS: Fourteen challenges have been analyzed to date. Six patients (43%) were female and 8 (57%) male. Average age was 11 months, range 6 -16 months. Seventy-one percent had eczema and 36% had egg allergy. Four (29%) had a peanut-allergic sibling. All 14 had skin prick testing performed, with mean wheal size 2.7mm (95% CI [1.7, 3.7]). Eight had serum peanut-specific IgE measured, mean 1.3 kU/L (95% CI [0.3, 2.3]). Two (14%, 95% CI [1.8, 42.8]) had symptoms during food challenge, both facial hives successfully treated with oral diphenhydramine alone. The remaining 12 were advised to consume 2 grams peanut butter or 2/3 of Bamba 1oz pack three times weekly. CONCLUSIONS: This study demonstrates a safe, practical means to implement LEAP study findings. We modified criteria to include infants with a peanut allergic sibling. We are aware this is controversial, but because of significant family anxiety around home introduction in these children, we included them. Challenges to date have been appropriate for the outpatient setting, with reactions easily managed.
413
The Role of Race in the Management of Peanut Allergy
Yasmin Hamzavi Abedi, MD1,2, Punita Ponda, MD, FAAAAI1,2, and Cristina P. Sison, PhD3; 1Division of Allergy and Immunology, Northwell Health, Great Neck, NY, 2Department of Medicine and Pediatrics, Hofstra Northwell School of Medicine, Hempstead, NY, 3Biostatistics Unit, Feinstein Institute for Medical Research, Northwell Health, Manhasset, NY. RATIONALE: Food specific IgE levels are used to predict the likelihood of clinical reactivity. Recent publications have implicated race as a factor in food sensitization, but how this may affect management of food allergy(FA) has not been elucidated. The primary objective of this study was to identify the impact of race on the rate of decline in peanut IgE. METHODS: We conducted a retrospective chart review of 250 patients, aged 0 to 17 years, of which 193 were diagnosed with peanut allergy. Peanut IgE, obtained during clinic visits between 01/01/2001 and 05/31/2016 were reviewed for each subject. A mixed models approach to repeated measures analysis of variance(RMANOVA) was used to compare race groups (white, black, asian) with respect to the patterns of change in peanut IgE over time. RESULTS: A significant increase in peanut IgE over time was observed among all races(p<0.0002). The rate of change in peanut IgE over time was not significantly different between black, white and asian children, after adjusting for age and atopic dermatitis. White and asian children showed an increasing trend in peanut IgE, while black children demonstrated a decreasing trend over time(p<0.099). CONCLUSIONS: Our data shows an increase in food allergic individuals’ peanut IgE over time across races. Although the rate of change was not significantly different between races, larger studies exploring factors (changes in testing methods, food avoidance, increasing sensitization, etc.) for the noted
414
Relative Value of Skin Prick, Specific Peanut Specific IgE and Component Tests in Predicting the Outcome of Oral Peanut Challenge
Shelly Rajput1, Peter D. Arkwright, MD, PhD, FAAAAI1, Carol Ewing2, Stephen Hughes2, and Vibha Sharma2; 1University of Manchester, Manchester, United Kingdom, 2Royal Manchester Children’s Hospital, Manchester, United Kingdom. RATIONALE: Although an oral food challenge is the gold standard for confirming peanut allergy, skin prick tests and peanut specific IgE and component testing are often used as surrogates. We studied the relative predictive value of these surrogate tests in predicting the outcome of peanut oral challenge of children attending a specialist pediatric allergy service in the U.K. METHODS: All children completing a formal peanut oral food challenge (OFC) at Royal Manchester Children’s Hospital, United Kingdom who had skin prick tests and blood taken to determine specific peanut IgE and Ara h 1, 2, 3, 8, 9 components were prospectively studied. RESULTS: 130 children (62% male) aged 1 - 18 (median 7) years were challenged with peanut between 2012 and 2016. 32% (42) failed the oral challenge. Previous history of peanut avoidance or reactions were poor predictors of OFC outcome. Only one child suffered anaphylaxis requiring _0.4 KIU/L epinephrine. Of the peanut allergen components, an Ara h2 of > had the highest predictive values (positive 94%, negative 97%); signifi_3mm (positive 75%, negative 76%) and cantly greater than skin prick tests > _0.4KIU/L (positive 81%, negative 84%). Two of 64 peanut specific IgE > children who had a negative Ara h 2 but failed the challenge, failed only after consuming >5 g of peanut. CONCLUSIONS: The Ara h 2 peanut component, although not completely perfect, provides an excellent surrogate test of clinical peanut allergy in children, and should replace specific peanut IgE as a standard test.
415
Wheat Protein Recognition Pattern in Thai Children with Wheat Allergy
Thatchai Wirodwanich, MD, Wipa Jessadapakorn, Araya Yuenyongviwat, MD, and Pasuree Sangsupawanich; Department of Pediatrics, Faculty of Medicine, Prince of Songkla University, Songkhla, Thailand. RATIONALE: Wheat is one of the most common food allergens in childhood. In contrast to other food allergies, wheat-specific immunoglobulin E (sIgE) correlates badly with clinical symptoms and omega-5 gliadin was identified mostly with wheat-dependent exercise-induced anaphylaxis (WDEIA). The aim of this study was to investigate a recognition pattern against wheat protein and omega-5 gliadin in Thai children with wheat allergy. METHODS: Children with IgE-mediated wheat allergy were enrolled from the pediatric allergy clinic of Songklanagarind Hospital from March 2014 to June 2016. Clinical reactions were determined and the levels of sIgE against wheat and omega-5 gliadin were measured. RESULTS: Thirty wheat allergic patients were characterized. Thirteen presented with anaphylaxis or WDEIA, while the others presented with acute urticarial (9/30) and atopic dermatitis (8/30). Twenty-two (73%) patients were sensitized to omega-5 gliadin. The correlation between the levels of sIgE to omega-5 gliadin and the skin prick test (SPT) was good (R50.66, p50.001) but there was no correlation between wheat sIgE and SPT (R50.34, p50.14). The levels of omega-5 gliadin-sIgE in the systemic reaction group (anaphylaxis and WDEIA) tended to be higher than the cutaneous group (urticaria and atopic dermatitis) (median 4.1 kUA/L vs 0.6 kUA/L, p50.155). Conversely patients in the cutaneous group had a higher level of wheat sIgE than patients in the systemic reaction group (median 10 kUA/L vs 2.5 kUA/L, p50.209). CONCLUSIONS: Detection of sIgE to omega-5 gliadin seems to be associated with wheat anaphylaxis. Testing for sIgE to omega-5 gliadin might be considered in wheat allergic patients presenting with IgEmediated systemic reaction.
412
J ALLERGY CLIN IMMUNOL FEBRUARY 2017
increase are warranted. Understanding the changes in peanut sensitization over time is a crucial step in determining likelihood of clinical reactivity.
Infant and Young Child Peanut Challenges, a Clinical Application of the Learning Early About Peanut Allergy Study 1
2
SUNDAY
Laura J. West, MD, PGY-3, Pediatrics Resident , Carolyn Baloh, MD , Hey Chong, MD, PhD1, Allyson S. Larkin, MD1, David R. Nash, MD1, John Broyles, CRNP1, Daniel G. Winger, MS3, Li Wang3, and Todd D. Green, MD4; 1Children’s Hospital of Pittsburgh of UPMC, Pittsburgh, PA, 2Duke Division of Allergy and Immunology, Durham, NC, 3University of Pittsburgh Clinical and Translational Science Institute, Pittsburgh, PA, 4Children’s Hospital of Pittsburgh of UPMC, Division of Pulmonary Medicine, Allergy and Immunology, Pittsburgh, PA. RATIONALE: The Learning Early About Peanut allergy (LEAP) and LEAP-On studies demonstrated decreased risk of peanut allergy with early peanut introduction in non-allergic, at-risk children. This retrospective chart review highlights a practical implementation of these findings. METHODS: Retrospective chart review of young children at risk for peanut allergy evaluated at Children’s Hospital of Pittsburgh of UPMC with a peanut food challenge between March 1, 2015 and July 31, 2016. Primary outcome was symptoms during challenge. Study was IRB exempt approved. RESULTS: Fourteen challenges have been analyzed to date. Six patients (43%) were female and 8 (57%) male. Average age was 11 months, range 6 -16 months. Seventy-one percent had eczema and 36% had egg allergy. Four (29%) had a peanut-allergic sibling. All 14 had skin prick testing performed, with mean wheal size 2.7mm (95% CI [1.7, 3.7]). Eight had serum peanut-specific IgE measured, mean 1.3 kU/L (95% CI [0.3, 2.3]). Two (14%, 95% CI [1.8, 42.8]) had symptoms during food challenge, both facial hives successfully treated with oral diphenhydramine alone. The remaining 12 were advised to consume 2 grams peanut butter or 2/3 of Bamba 1oz pack three times weekly. CONCLUSIONS: This study demonstrates a safe, practical means to implement LEAP study findings. We modified criteria to include infants with a peanut allergic sibling. We are aware this is controversial, but because of significant family anxiety around home introduction in these children, we included them. Challenges to date have been appropriate for the outpatient setting, with reactions easily managed.
413
The Role of Race in the Management of Peanut Allergy
Yasmin Hamzavi Abedi, MD1,2, Punita Ponda, MD, FAAAAI1,2, and Cristina P. Sison, PhD3; 1Division of Allergy and Immunology, Northwell Health, Great Neck, NY, 2Department of Medicine and Pediatrics, Hofstra Northwell School of Medicine, Hempstead, NY, 3Biostatistics Unit, Feinstein Institute for Medical Research, Northwell Health, Manhasset, NY. RATIONALE: Food specific IgE levels are used to predict the likelihood of clinical reactivity. Recent publications have implicated race as a factor in food sensitization, but how this may affect management of food allergy(FA) has not been elucidated. The primary objective of this study was to identify the impact of race on the rate of decline in peanut IgE. METHODS: We conducted a retrospective chart review of 250 patients, aged 0 to 17 years, of which 193 were diagnosed with peanut allergy. Peanut IgE, obtained during clinic visits between 01/01/2001 and 05/31/2016 were reviewed for each subject. A mixed models approach to repeated measures analysis of variance(RMANOVA) was used to compare race groups (white, black, asian) with respect to the patterns of change in peanut IgE over time. RESULTS: A significant increase in peanut IgE over time was observed among all races(p<0.0002). The rate of change in peanut IgE over time was not significantly different between black, white and asian children, after adjusting for age and atopic dermatitis. White and asian children showed an increasing trend in peanut IgE, while black children demonstrated a decreasing trend over time(p<0.099). CONCLUSIONS: Our data shows an increase in food allergic individuals’ peanut IgE over time across races. Although the rate of change was not significantly different between races, larger studies exploring factors (changes in testing methods, food avoidance, increasing sensitization, etc.) for the noted
414
Relative Value of Skin Prick, Specific Peanut Specific IgE and Component Tests in Predicting the Outcome of Oral Peanut Challenge
Shelly Rajput1, Peter D. Arkwright, MD, PhD, FAAAAI1, Carol Ewing2, Stephen Hughes2, and Vibha Sharma2; 1University of Manchester, Manchester, United Kingdom, 2Royal Manchester Children’s Hospital, Manchester, United Kingdom. RATIONALE: Although an oral food challenge is the gold standard for confirming peanut allergy, skin prick tests and peanut specific IgE and component testing are often used as surrogates. We studied the relative predictive value of these surrogate tests in predicting the outcome of peanut oral challenge of children attending a specialist pediatric allergy service in the U.K. METHODS: All children completing a formal peanut oral food challenge (OFC) at Royal Manchester Children’s Hospital, United Kingdom who had skin prick tests and blood taken to determine specific peanut IgE and Ara h 1, 2, 3, 8, 9 components were prospectively studied. RESULTS: 130 children (62% male) aged 1 - 18 (median 7) years were challenged with peanut between 2012 and 2016. 32% (42) failed the oral challenge. Previous history of peanut avoidance or reactions were poor predictors of OFC outcome. Only one child suffered anaphylaxis requiring _0.4 KIU/L epinephrine. Of the peanut allergen components, an Ara h2 of > had the highest predictive values (positive 94%, negative 97%); signifi_3mm (positive 75%, negative 76%) and cantly greater than skin prick tests > _0.4KIU/L (positive 81%, negative 84%). Two of 64 peanut specific IgE > children who had a negative Ara h 2 but failed the challenge, failed only after consuming >5 g of peanut. CONCLUSIONS: The Ara h 2 peanut component, although not completely perfect, provides an excellent surrogate test of clinical peanut allergy in children, and should replace specific peanut IgE as a standard test.
415
Wheat Protein Recognition Pattern in Thai Children with Wheat Allergy
Thatchai Wirodwanich, MD, Wipa Jessadapakorn, Araya Yuenyongviwat, MD, and Pasuree Sangsupawanich; Department of Pediatrics, Faculty of Medicine, Prince of Songkla University, Songkhla, Thailand. RATIONALE: Wheat is one of the most common food allergens in childhood. In contrast to other food allergies, wheat-specific immunoglobulin E (sIgE) correlates badly with clinical symptoms and omega-5 gliadin was identified mostly with wheat-dependent exercise-induced anaphylaxis (WDEIA). The aim of this study was to investigate a recognition pattern against wheat protein and omega-5 gliadin in Thai children with wheat allergy. METHODS: Children with IgE-mediated wheat allergy were enrolled from the pediatric allergy clinic of Songklanagarind Hospital from March 2014 to June 2016. Clinical reactions were determined and the levels of sIgE against wheat and omega-5 gliadin were measured. RESULTS: Thirty wheat allergic patients were characterized. Thirteen presented with anaphylaxis or WDEIA, while the others presented with acute urticarial (9/30) and atopic dermatitis (8/30). Twenty-two (73%) patients were sensitized to omega-5 gliadin. The correlation between the levels of sIgE to omega-5 gliadin and the skin prick test (SPT) was good (R50.66, p50.001) but there was no correlation between wheat sIgE and SPT (R50.34, p50.14). The levels of omega-5 gliadin-sIgE in the systemic reaction group (anaphylaxis and WDEIA) tended to be higher than the cutaneous group (urticaria and atopic dermatitis) (median 4.1 kUA/L vs 0.6 kUA/L, p50.155). Conversely patients in the cutaneous group had a higher level of wheat sIgE than patients in the systemic reaction group (median 10 kUA/L vs 2.5 kUA/L, p50.209). CONCLUSIONS: Detection of sIgE to omega-5 gliadin seems to be associated with wheat anaphylaxis. Testing for sIgE to omega-5 gliadin might be considered in wheat allergic patients presenting with IgEmediated systemic reaction.