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In Vitro Safety Profile of a Depigmented-Polymerized Peanut Allergenic Extract
AB258 Abstracts
808
In Vitro Safety Profile of a DepigmentedPolymerized Peanut Allergenic Extract
Jeronimo Carnes1, Mayte Gallego1, Maria Morales Esteban1, Raquel Moya1, Victor Iraola1, Marta Taules2, and Philippe A. Eigenmann, MD, FAAAAI3; 1R&D Department. Laboratorios LETI S.L., Madrid, Spain, 2 Centres Cientıfics i Tecnologics, Universidad de Barcelona, Barcelona, Spain, 3Geneva University Hospitals, Geneva, Switzerland. RATIONALE: Several alternatives have been developed for the treatment of peanut allergy. Safety is the most challenging issue and the main reason why subcutaneous immunotherapy has not been more extensively studied. This study aims to develop and characterize a depigmented-polymerized peanut extract designed according to their safety profile. METHODS: Peanut native extract (NE) was manufactured after the extraction of the protein fraction from roasted peanuts. This fraction was dialyzed and freeze-dried. Afterwards, the NE was purified (mild acid treatment) to remove low MW substances (depigmentation) and finally polymerized with glutaraldehyde (PE). Both extracts were characterized by: Size exclusion chromatography to determine their protein profile. Allergenic activity was compared by ELISA inhibition. IgE-binding stability was measured by surface plasmon resonance (Biacore T100) using sera from allergic patients. RESULTS: The chromatogram of the NE showed the presence of several peaks in a distribution between 9 to 100 kDa while the PE showed a clear modification. ELISA inhibition confirmed the reduction of the IgE binding capacity of PE (10 times). The stability of the IgE in complex with Ara h 1 (Kd50.00183 s-1 and t½5377.8 s), NE (Kd50.00203 s-1 and t½5341.8 s) and PE (Kd50.0042 s-1 and t ½5156.8 s) was significantly lower in PE, confirming the safety profile. CONCLUSIONS: A depigmented-polymerized peanut extract with an excellent profile of safety has been developed. The in vitro results demonstrated a reduction of the allergenicity while maintaining the allergen composition. Further studies are under development to confirm the safety profile in animal models.
MONDAY
809
Fraction of Exhaled Nitric Oxide (FeNO) As A Predictor Of GI Symptoms During Food Allergen Updosing
Madeleine B. Chollet, MD, PhD, Kari C. Nadeau, MD, PhD, FAAAAI, Natasha Purington, MS, Manisha Desai, PhD, and R. Sharon Chinthrajah, MD; Stanford University, Stanford, CA. RATIONALE: FeNO is used as a marker for eosinophilic inflammation in the management of asthma. An elevated FeNO has also been shown to be a predictor of abdominal pain and vomiting in double-blind placebocontrolled food challenges. The purpose of this study was to determine if FeNO could be used to predict patients who would experience GI symptoms during the updosing phase of an oral immunotherapy clinical trial. METHODS: Twenty-seven patients who consented to participate in an IRB-approved oral immunotherapy clinical trial conducted at the Sean N. Parker Center for Allergy Research were included in this study. We measured FeNO prior to the patient’s scheduled updosing in clinic during the desensitization period of the trial. FeNO was obtained according to ATS guidelines using Niox Mino. RESULTS: Twelve (44%) of the twenty-seven patients experienced at least one GI symptom defined as nausea, vomiting, and/or abdominal pain. FeNO was significantly higher in patients with GI symptoms than in patients without these symptoms as revealed by a two-sample t-test (p 5 0.04). Mean FeNO was 40 ppb in patients with GI symptoms compared to 20 ppb in patients without GI symptoms. The Wilcoxon rank-sum test revealed no significant differences between groups in regards to sex, age, history of asthma, and history of allergic rhinitis (p > 0.05). CONCLUSIONS: These results suggest that an elevated FeNO may be associated with abdominal pain, nausea, and/or vomiting during updosing.
J ALLERGY CLIN IMMUNOL FEBRUARY 2017
If confirmed by a larger sample, this study would indicate that FeNO can be used to guide updosing decisions.
810
''Real Life'' Outcome of Oral Immunotherapy for Severe Food Allergy
Keiko Kameda1, Junya Hirayama1, Mizuho Nagao, MD1, Naoka Itoh-Nagato2, Naoki Shimojo, MD3, Tsutomu Iwata4, and Takao Fujisawa, MD, PhD1; 1Institute for Clinical Research, Mie National Hospital, Tsu, Japan, 2Department of Pediatrics, Shimoshizu National Hospital, Yotsukaido, Japan, 3Department of Pediatrics Graduate School of Medicine Chiba University, Chiba, Japan, 4Department of Education for Childcare, Tokyo Kasei University, Sayama, Japan. RATIONALE: Oral immunotherapy (OIT) is expected to be a promising intervention for severe food allergy and recent clinical studies have demonstrated high achievement of sustained unresponsiveness by OIT. The results, however, obtained under well-designed, strict protocol. ‘‘Real life’’ outcome after off-protocol of OIT is not well known. METHODS: The study initially enrolled 45 and 32 children (5-15 years old) with severe IgE-mediated hen’s egg and milk allergy, respectively, to prove desensitization induction by rush OIT in a randomized delayed control fashion. Protocol-based allergenic food intake was maintained for 12 months, then the subjects were allowed to take ‘‘freely’’ the food under vigilance of anaphylaxis. We surveyed actual daily intake of the food at 2, 3, 4 and 5 years off-protocol and measured specific IgE and IgG4 levels RESULTS: On protocol at 1 year of maintenance OIT, 82% of egg allergy patients were able to eat half-boiled egg and 66% of milk allergy patients ate 200ml of milk. At 2 years off-protocol, the number decreased to 42% and 43% in egg and milk allergy, respectively. At 3 years and thereafter, about 30 % and 35% maintained initially achieved doses, respectively. All other patients maintained small amount of the allergenic food. No patients experienced anaphylaxis requiring epinephrine. Many patients admitted that the food tasted ‘‘bad’’. There were no differences in specific IgE and IgG4 levels between patients with high and low intake. CONCLUSIONS: OIT hardly induced high-dose unresponsiveness in real life but achieved small but safe intake levels of allergenic food.
808
In Vitro Safety Profile of a DepigmentedPolymerized Peanut Allergenic Extract
Jeronimo Carnes1, Mayte Gallego1, Maria Morales Esteban1, Raquel Moya1, Victor Iraola1, Marta Taules2, and Philippe A. Eigenmann, MD, FAAAAI3; 1R&D Department. Laboratorios LETI S.L., Madrid, Spain, 2 Centres Cientıfics i Tecnologics, Universidad de Barcelona, Barcelona, Spain, 3Geneva University Hospitals, Geneva, Switzerland. RATIONALE: Several alternatives have been developed for the treatment of peanut allergy. Safety is the most challenging issue and the main reason why subcutaneous immunotherapy has not been more extensively studied. This study aims to develop and characterize a depigmented-polymerized peanut extract designed according to their safety profile. METHODS: Peanut native extract (NE) was manufactured after the extraction of the protein fraction from roasted peanuts. This fraction was dialyzed and freeze-dried. Afterwards, the NE was purified (mild acid treatment) to remove low MW substances (depigmentation) and finally polymerized with glutaraldehyde (PE). Both extracts were characterized by: Size exclusion chromatography to determine their protein profile. Allergenic activity was compared by ELISA inhibition. IgE-binding stability was measured by surface plasmon resonance (Biacore T100) using sera from allergic patients. RESULTS: The chromatogram of the NE showed the presence of several peaks in a distribution between 9 to 100 kDa while the PE showed a clear modification. ELISA inhibition confirmed the reduction of the IgE binding capacity of PE (10 times). The stability of the IgE in complex with Ara h 1 (Kd50.00183 s-1 and t½5377.8 s), NE (Kd50.00203 s-1 and t½5341.8 s) and PE (Kd50.0042 s-1 and t ½5156.8 s) was significantly lower in PE, confirming the safety profile. CONCLUSIONS: A depigmented-polymerized peanut extract with an excellent profile of safety has been developed. The in vitro results demonstrated a reduction of the allergenicity while maintaining the allergen composition. Further studies are under development to confirm the safety profile in animal models.
MONDAY
809
Fraction of Exhaled Nitric Oxide (FeNO) As A Predictor Of GI Symptoms During Food Allergen Updosing
Madeleine B. Chollet, MD, PhD, Kari C. Nadeau, MD, PhD, FAAAAI, Natasha Purington, MS, Manisha Desai, PhD, and R. Sharon Chinthrajah, MD; Stanford University, Stanford, CA. RATIONALE: FeNO is used as a marker for eosinophilic inflammation in the management of asthma. An elevated FeNO has also been shown to be a predictor of abdominal pain and vomiting in double-blind placebocontrolled food challenges. The purpose of this study was to determine if FeNO could be used to predict patients who would experience GI symptoms during the updosing phase of an oral immunotherapy clinical trial. METHODS: Twenty-seven patients who consented to participate in an IRB-approved oral immunotherapy clinical trial conducted at the Sean N. Parker Center for Allergy Research were included in this study. We measured FeNO prior to the patient’s scheduled updosing in clinic during the desensitization period of the trial. FeNO was obtained according to ATS guidelines using Niox Mino. RESULTS: Twelve (44%) of the twenty-seven patients experienced at least one GI symptom defined as nausea, vomiting, and/or abdominal pain. FeNO was significantly higher in patients with GI symptoms than in patients without these symptoms as revealed by a two-sample t-test (p 5 0.04). Mean FeNO was 40 ppb in patients with GI symptoms compared to 20 ppb in patients without GI symptoms. The Wilcoxon rank-sum test revealed no significant differences between groups in regards to sex, age, history of asthma, and history of allergic rhinitis (p > 0.05). CONCLUSIONS: These results suggest that an elevated FeNO may be associated with abdominal pain, nausea, and/or vomiting during updosing.
J ALLERGY CLIN IMMUNOL FEBRUARY 2017
If confirmed by a larger sample, this study would indicate that FeNO can be used to guide updosing decisions.
810
''Real Life'' Outcome of Oral Immunotherapy for Severe Food Allergy
Keiko Kameda1, Junya Hirayama1, Mizuho Nagao, MD1, Naoka Itoh-Nagato2, Naoki Shimojo, MD3, Tsutomu Iwata4, and Takao Fujisawa, MD, PhD1; 1Institute for Clinical Research, Mie National Hospital, Tsu, Japan, 2Department of Pediatrics, Shimoshizu National Hospital, Yotsukaido, Japan, 3Department of Pediatrics Graduate School of Medicine Chiba University, Chiba, Japan, 4Department of Education for Childcare, Tokyo Kasei University, Sayama, Japan. RATIONALE: Oral immunotherapy (OIT) is expected to be a promising intervention for severe food allergy and recent clinical studies have demonstrated high achievement of sustained unresponsiveness by OIT. The results, however, obtained under well-designed, strict protocol. ‘‘Real life’’ outcome after off-protocol of OIT is not well known. METHODS: The study initially enrolled 45 and 32 children (5-15 years old) with severe IgE-mediated hen’s egg and milk allergy, respectively, to prove desensitization induction by rush OIT in a randomized delayed control fashion. Protocol-based allergenic food intake was maintained for 12 months, then the subjects were allowed to take ‘‘freely’’ the food under vigilance of anaphylaxis. We surveyed actual daily intake of the food at 2, 3, 4 and 5 years off-protocol and measured specific IgE and IgG4 levels RESULTS: On protocol at 1 year of maintenance OIT, 82% of egg allergy patients were able to eat half-boiled egg and 66% of milk allergy patients ate 200ml of milk. At 2 years off-protocol, the number decreased to 42% and 43% in egg and milk allergy, respectively. At 3 years and thereafter, about 30 % and 35% maintained initially achieved doses, respectively. All other patients maintained small amount of the allergenic food. No patients experienced anaphylaxis requiring epinephrine. Many patients admitted that the food tasted ‘‘bad’’. There were no differences in specific IgE and IgG4 levels between patients with high and low intake. CONCLUSIONS: OIT hardly induced high-dose unresponsiveness in real life but achieved small but safe intake levels of allergenic food.