- Email: [email protected]
Basophil Allergen Threshold Sensitivity, CD-sens, in Relation to DBPCFC to Peanut in Children with Suspected Peanut Allergy
Abstracts AB85
J ALLERGY CLIN IMMUNOL VOLUME 125, NUMBER 2
Basophil Allergen Threshold Sensitivity, CD-sens, in Relation to DBPCFC to Peanut in Children with Suspected Peanut Allergy S. Glaumann1, C. Nilsson1, C. Lindquist1, G. Lilja1, J. Ade´doyin2, M. Borres3, M. Berthold4, A. Nopp2, S. G. O. Johansson2; 1Department of Clinical Science and Education, So¨dersjukhuset, Karolinska Institutet, Stockholm, SWEDEN, 2Department of Medicine, Clinical Immunology and Allergy Unit, Karolinska University Hospital, Stockholm, SWEDEN, 3 Phadia AB, Uppsala, SWEDEN, 4Meira Medical Int. AB, Stockholm, SWEDEN. RATIONALE: Double blind placebo controlled food challenge (DBPCFC), the existing golden standard for diagnosing food allergy, is both time-consuming and potentially dangerous. We have related the basophil allergen threshold sensitivity (CD-sens) to the outcome of DBPCFC in children with suspected peanut allergy. METHODS: DBPCFC was performed with increasing concentrations of peanut allergen (1 mg to 5 g of peanut) in 16 children with suspected IgE-mediated peanut-allergy. At the challenges blood samples were taken for evaluation of CD-sens and quantification of IgE- and IgG4-antibodies to peanut and Ara h2. Basophils were stimulated in vitro with peanut allergen and Ara h2 in descending doses until the threshold sensitivity was reached. CD-sens was defined on the basis of the allergen dose giving 50% of maximal basophil response, measured as expression of CD63. RESULTS: Of 16 children 5 reacted with clinical allergic symptoms on DBPCFC. Absolute IgE antibody levels to peanut were 26.4-134 kUA/L and the IgE antibody fraction, (% IgE antibody to peanut of total IgE), varied between 9.5-26.0%. Remaining 11 children had low levels of IgE antibodies 0.1-1.3 kUA/L, and did not react on DBPCFC. Children with positive challenge presented reacting basophils after stimulation in contrast to none of the children with negative challenge. CONCLUSIONS: CD-sens seems to correlate with DBPCFC to peanut and could be a complement/substitute to DBPCFC and thereby save patients from cumbersome clinical procedures as well as save time and money for the medical system.
334
Specific IgE To High Molecular Weight Wheat Proteins In Wheat Sensitized Pollen Allergic Individuals C. Eriksson, F. Bernhardsson, M. Poorafshar; Phadia AB, Uppsala, SWEDEN. RATIONALE: A clinically irrelevant sensitisation to wheat flour is common among adults possibly due to cross-reactions between wheat and grass pollen. Clinically significant wheat allergens have been described and include gliadins, alpha amylase inhibitors (AAI) and lipid transfer protein (LTP). The aim of this study was to investigate the sensitisation pattern for wheat sensitised timothy grass pollen allergic patients. METHODS: Sera from timothy grass pollen allergic patients without any symptoms following intake of wheat and control subjects with wheat allergy were included. Specific IgE (sIgE) to timothy grass pollen and wheat flour was determined with ImmunoCAPÒ (Phadia AB, Sweden) and sIgE to glutenins, gliadins, AAI, wheat LTP was determined with an experimental microarray immunoassay. All sera were also subjected to RAST inhibition with grass pollen and analysed with western blot to wheat water/salt soluble proteins. RESULTS: The sera from wheat allergic patients showed IgE reactivity to the clinically significant allergens gliadins, AAI and/or wheat LTP respectively. In contrast, the sera from wheat sensitised timothy pollen allergic patients did not show IgE reactivity to any of these clinically relevant allergens. Inhibition with timothy grass pollen reduced the level of sIgE to wheat with up to 99% for the pollen allergic individuals. Western blots showed that this group of patients mainly were sensitised to high molecular weight water/salt soluble wheat proteins. CONCLUSIONS: This finding indicates the importance of measuring sIgE to different wheat components to distinguish a true wheat allergy from a clinically irrelevant wheat sensitisation.
335
Introduction of Allergenic Food after Positive Oral Food Challenge Test K. Otsuji1, M. Hirayama1, N. Kando1, K. Ito1, T. Muto2, T. Sakamoto2; 1 Aichi Children’s Health and Medical Center, Obu, JAPAN, 2Nagoya University Graduate School of Medicine, Nagoya, JAPAN. RATIONALE: Strict food elimination is generally advised after a positive oral food challenge (OFC). However, small amounts of allergenic foods may be tolerated even after a positive OFC. METHODS: Children with negative (n510) and positive (mild symptoms) (n510) OFC with boiled egg white were instructed to introduce heated egg products in their diet twice a week. Based on the total dose and severity of symptoms in the OFC, the amounts of heated egg to be ingested were established as: levels 0 (trace), 1 (1/20), 2 (1/8), 3 (1/4) and 4 (1/2). A handmade booklet with information about the egg contents in commercial processed foods was provided to the parents. The outcomes were evaluated after 2 to 3 months, based on the recordings in a food diary. RESULTS: Twelve patients (including 6 with positive OFC) ingested recommended levels of egg products. Although allergic symptoms initially appeared in 7 (including 4 with a positive OFC), all subsequently tolerated to the levels. The remaining 8 patients ingested lesser than advised or unknown amounts of the egg products, and 2 of them reported trivial symptoms. Among the 14 allergic events observed, 8 occurred after intake of an unknown amount of the egg products or insufficiently heated egg, and 6 occurred after intake at the levels advised. All symptoms were mild and transient, and did not require any visits to the emergency department. CONCLUSIONS: Patients with egg allergy do not always have to completely eliminate eggs from their diets, even after positive OFC.
336
Clinical Characteristics of Children with Food ProteinInduced Enterocolitis (FPIES) K. M. Jarvinen-Seppo, L. Sickles, A. H. Nowak-Wegrzyn; Mt. Sinai Medical Center, New York, NY. RATIONALE: The clinical characteristics of children with FPIES have not been described in large patient populations. METHODS: We analyzed records of children with FPIES evaluated in the Allergy Clinics between 2001 and 2009. RESULTS: Seventy six children with FPIES were identified. The median age at 1st reaction was 4 months (range; 1 day, 14 months); milk at 2 months, soy at 2 months, rice at 5 months, oat at 6 months. Foods responsible for reactions included: milk 44 (58%), soy 36 (47%), rice 18 (24%), oat 12 (16%), beef 4 (5%), egg and barley 3 each (4%), peanut 2 (3%); wheat, chicken, turkey, and fish- 1 each (1%). Forty two (55%) children reacted to a single food, 16 (21%) reacted to solid foods only; 15 (20%) reacted to soy and milk (no solid foods), and 13 (17%) reacted to milk and or soy and at least one solid food. Among 44 children with milk-FPIES, 45% had soy-FPIES and 25% had solid food-FPIES. Among 36 children with soy-FPIES, 56% had milk-FPIES and 19% had solid food-FPIES. Percentage of children who became tolerant at a median age was: milk55% at 32 months, soy-28% at 34.5 months, rice-50% at 42 months, oat58% at 45 months. CONCLUSIONS: Milk, soy, rice, and oat are the most common foods implicated in FPIES; beef, egg, and peanut might also induce FPIES. Children with milk/soy-FPIES are at high risk for reacting to other foods. For milk, oat and rice, the majority of children become tolerant by 3 to 4 years.
SUNDAY
333
J ALLERGY CLIN IMMUNOL VOLUME 125, NUMBER 2
Basophil Allergen Threshold Sensitivity, CD-sens, in Relation to DBPCFC to Peanut in Children with Suspected Peanut Allergy S. Glaumann1, C. Nilsson1, C. Lindquist1, G. Lilja1, J. Ade´doyin2, M. Borres3, M. Berthold4, A. Nopp2, S. G. O. Johansson2; 1Department of Clinical Science and Education, So¨dersjukhuset, Karolinska Institutet, Stockholm, SWEDEN, 2Department of Medicine, Clinical Immunology and Allergy Unit, Karolinska University Hospital, Stockholm, SWEDEN, 3 Phadia AB, Uppsala, SWEDEN, 4Meira Medical Int. AB, Stockholm, SWEDEN. RATIONALE: Double blind placebo controlled food challenge (DBPCFC), the existing golden standard for diagnosing food allergy, is both time-consuming and potentially dangerous. We have related the basophil allergen threshold sensitivity (CD-sens) to the outcome of DBPCFC in children with suspected peanut allergy. METHODS: DBPCFC was performed with increasing concentrations of peanut allergen (1 mg to 5 g of peanut) in 16 children with suspected IgE-mediated peanut-allergy. At the challenges blood samples were taken for evaluation of CD-sens and quantification of IgE- and IgG4-antibodies to peanut and Ara h2. Basophils were stimulated in vitro with peanut allergen and Ara h2 in descending doses until the threshold sensitivity was reached. CD-sens was defined on the basis of the allergen dose giving 50% of maximal basophil response, measured as expression of CD63. RESULTS: Of 16 children 5 reacted with clinical allergic symptoms on DBPCFC. Absolute IgE antibody levels to peanut were 26.4-134 kUA/L and the IgE antibody fraction, (% IgE antibody to peanut of total IgE), varied between 9.5-26.0%. Remaining 11 children had low levels of IgE antibodies 0.1-1.3 kUA/L, and did not react on DBPCFC. Children with positive challenge presented reacting basophils after stimulation in contrast to none of the children with negative challenge. CONCLUSIONS: CD-sens seems to correlate with DBPCFC to peanut and could be a complement/substitute to DBPCFC and thereby save patients from cumbersome clinical procedures as well as save time and money for the medical system.
334
Specific IgE To High Molecular Weight Wheat Proteins In Wheat Sensitized Pollen Allergic Individuals C. Eriksson, F. Bernhardsson, M. Poorafshar; Phadia AB, Uppsala, SWEDEN. RATIONALE: A clinically irrelevant sensitisation to wheat flour is common among adults possibly due to cross-reactions between wheat and grass pollen. Clinically significant wheat allergens have been described and include gliadins, alpha amylase inhibitors (AAI) and lipid transfer protein (LTP). The aim of this study was to investigate the sensitisation pattern for wheat sensitised timothy grass pollen allergic patients. METHODS: Sera from timothy grass pollen allergic patients without any symptoms following intake of wheat and control subjects with wheat allergy were included. Specific IgE (sIgE) to timothy grass pollen and wheat flour was determined with ImmunoCAPÒ (Phadia AB, Sweden) and sIgE to glutenins, gliadins, AAI, wheat LTP was determined with an experimental microarray immunoassay. All sera were also subjected to RAST inhibition with grass pollen and analysed with western blot to wheat water/salt soluble proteins. RESULTS: The sera from wheat allergic patients showed IgE reactivity to the clinically significant allergens gliadins, AAI and/or wheat LTP respectively. In contrast, the sera from wheat sensitised timothy pollen allergic patients did not show IgE reactivity to any of these clinically relevant allergens. Inhibition with timothy grass pollen reduced the level of sIgE to wheat with up to 99% for the pollen allergic individuals. Western blots showed that this group of patients mainly were sensitised to high molecular weight water/salt soluble wheat proteins. CONCLUSIONS: This finding indicates the importance of measuring sIgE to different wheat components to distinguish a true wheat allergy from a clinically irrelevant wheat sensitisation.
335
Introduction of Allergenic Food after Positive Oral Food Challenge Test K. Otsuji1, M. Hirayama1, N. Kando1, K. Ito1, T. Muto2, T. Sakamoto2; 1 Aichi Children’s Health and Medical Center, Obu, JAPAN, 2Nagoya University Graduate School of Medicine, Nagoya, JAPAN. RATIONALE: Strict food elimination is generally advised after a positive oral food challenge (OFC). However, small amounts of allergenic foods may be tolerated even after a positive OFC. METHODS: Children with negative (n510) and positive (mild symptoms) (n510) OFC with boiled egg white were instructed to introduce heated egg products in their diet twice a week. Based on the total dose and severity of symptoms in the OFC, the amounts of heated egg to be ingested were established as: levels 0 (trace), 1 (1/20), 2 (1/8), 3 (1/4) and 4 (1/2). A handmade booklet with information about the egg contents in commercial processed foods was provided to the parents. The outcomes were evaluated after 2 to 3 months, based on the recordings in a food diary. RESULTS: Twelve patients (including 6 with positive OFC) ingested recommended levels of egg products. Although allergic symptoms initially appeared in 7 (including 4 with a positive OFC), all subsequently tolerated to the levels. The remaining 8 patients ingested lesser than advised or unknown amounts of the egg products, and 2 of them reported trivial symptoms. Among the 14 allergic events observed, 8 occurred after intake of an unknown amount of the egg products or insufficiently heated egg, and 6 occurred after intake at the levels advised. All symptoms were mild and transient, and did not require any visits to the emergency department. CONCLUSIONS: Patients with egg allergy do not always have to completely eliminate eggs from their diets, even after positive OFC.
336
Clinical Characteristics of Children with Food ProteinInduced Enterocolitis (FPIES) K. M. Jarvinen-Seppo, L. Sickles, A. H. Nowak-Wegrzyn; Mt. Sinai Medical Center, New York, NY. RATIONALE: The clinical characteristics of children with FPIES have not been described in large patient populations. METHODS: We analyzed records of children with FPIES evaluated in the Allergy Clinics between 2001 and 2009. RESULTS: Seventy six children with FPIES were identified. The median age at 1st reaction was 4 months (range; 1 day, 14 months); milk at 2 months, soy at 2 months, rice at 5 months, oat at 6 months. Foods responsible for reactions included: milk 44 (58%), soy 36 (47%), rice 18 (24%), oat 12 (16%), beef 4 (5%), egg and barley 3 each (4%), peanut 2 (3%); wheat, chicken, turkey, and fish- 1 each (1%). Forty two (55%) children reacted to a single food, 16 (21%) reacted to solid foods only; 15 (20%) reacted to soy and milk (no solid foods), and 13 (17%) reacted to milk and or soy and at least one solid food. Among 44 children with milk-FPIES, 45% had soy-FPIES and 25% had solid food-FPIES. Among 36 children with soy-FPIES, 56% had milk-FPIES and 19% had solid food-FPIES. Percentage of children who became tolerant at a median age was: milk55% at 32 months, soy-28% at 34.5 months, rice-50% at 42 months, oat58% at 45 months. CONCLUSIONS: Milk, soy, rice, and oat are the most common foods implicated in FPIES; beef, egg, and peanut might also induce FPIES. Children with milk/soy-FPIES are at high risk for reacting to other foods. For milk, oat and rice, the majority of children become tolerant by 3 to 4 years.
SUNDAY
333