- Email: [email protected]
Comparison of Cetirizine to Diphenhydramine in the Treatment of Acute Food Allergic Reactions
AB236 Abstracts
911
Role Of Disulfide Bridges In The Proteolytic Susceptibility And Allergenicity Of Ara H 6, A Major Allergen From Peanut B. Guillon1, S. Hazebrouck1, K. Adel-Patient1, E. Paty2, P. Scheinmann2, J. M. Wal1, H. Bernard1; 1INRA, Gif sur Yvette, FRANCE, 2H^opital Necker Enfants Malades, Paris, FRANCE. RATIONALE: Five disulfide (S-S) bridges stabilize the structure of Ara h 6. We investigated the impact of each S-S bridge on Ara h 6 susceptibility to pepsin and trypsin digestion and on its immunoreactivity. METHODS: Progressive deletion of the S-S bridges by substituting alanine for cysteine was performed on a recombinant Ara h 6. Proteolysis by pepsin and trypsin were followed using SDS-PAGE and the peptides produced during digestion were identified by mass spectrometry. Immunoreactivity of the recombinant proteins and their proteolytic fragments was assessed by IgE binding studies using sera from 5 peanut-allergic patients sensitized to Ara h 6. The capacity to induce the degranulation of humanized rat mast cells passively sensitized with human specific IgE was also evaluated. RESULTS: The recombinant Ara h 6 and the mutant lacking the C-terminal (C84-C124) S-S bridge exhibited identical structure to and the same immunoreactivity as the natural counterpart. The loss of an additional S-S bridge slightly decreased the protein immunoreactivity. However, the susceptibility to proteolysis was highly dependant on the S-S bridge deleted. Complete degradation of Ara h 6 by pepsin and trypsin occurred when the central S-S bridges (C26-C58 or C59-C107) were mutated, thus leading to a total loss of allergenicity after digestion. Immunoreactivity of Ara h 6 was conserved only when a heterodimeric structure, characteristic of the 2S albumin, was preserved after digestion. CONCLUSIONS: The central S-S bridges stabilize the protease-resistant core of Ara h 6 and have a major role on its structure and biological properties. The Use of Epinephrine for the Treatment of Initial Allergic Reactions to Peanut M. Ben-Shoshan1, L. Soller2, R. Alizadehfar1, J. Fragapane3, L. Joseph3,4, Y. St. Pierre3, L. Harada5, M. Allen6, A. Clarke3,7; 1McGill University Montreal Children Hospital, Montreal, QC, CANADA, 2Division of Pediatric Allergy and Clinical Immunology, Department of Pediatrics, McGill University Health Center, Montreal, Quebec, Canada, Montreal, QC, CANADA, 3Division of Clinical Epidemiology, Department of Medicine, McGill University Health Center, Montreal, QC, CANADA, 4Departments of Epidemiology and Biostatistics, McGill University, Montreal, QC, CANADA, 5Anaphylaxis Canada, Toronto, ON, CANADA, 6Allergy/Asthma Information Association, Toronto, ON, CANADA, 7Division of Allergy and Clinical Immunology, Department of Medicine, McGill University Health Center, Montreal, QC, CANADA. RATIONALE: To assess the use of epinephrine to treat initial allergic reactions to peanut in health care facilities (HCF). METHODS: Parents of children with an allergist-confirmed peanut allergy recruited from the Montreal Children’s Hospital and from PanCanadian food allergy advocacy associations were queried on the management of the initial allergic reactions. RESULTS: Six hundred twenty-nine individuals reported an initial allergic reaction to peanut. Median age of initial reaction was 1.6 years (IQR, 1.1, 2.6) and 46.1% (95% CI, 42.2, 50.1) were brought to HCFs. Epinephrine was administered to 23.1% (95% CI, 18.4, 28.4) of those brought to HCFs. Among those with moderate/severe reactions, 55.2% (95% CI, 50.5, 59.7) were brought to HCFs, and 24.9% (95% CI, 19.7, 30.7) of these received epinephrine. Epinephrine auto-injector (EAI) was prescribed in 58.0% (95% CI, 51.5, 64.3) of cases brought to HCF. Factors associated with epinephrine treatment in a HCF were the presence of a severe reaction [OR 3.26 (95% CI, 1.72, 6.15)] and a family history of atopy [OR 2.25 (95% CI, 1.20, 4.20)]. Factors associated with EAI prescription were use of epinephrine for the initial reaction: [OR 5.23 (95% CI, 2.39, 11.45)]; living in Quebec: [OR 2.55 (95% CI, 1.43, 4.56)] and calendar year of initial reaction [OR 1.09 95% CI 1.02, 1.16)]. CONCLUSIONS: Our results reveal underuse of epinephrine and low rates of EAI prescriptions in HCFs. Guidelines prompting epinephrine use and prescription to all individuals presenting with a likely allergic reaction to peanut are required.
912
J ALLERGY CLIN IMMUNOL FEBRUARY 2011
913
Food Avoidance Following Physician Diagnosis Of Food Allergy: Results From A Canadian Study L. Soller1, J. Fragapane1, M. Ben-Shoshan1, D. Harrington2, R. Alizadehfar1, L. Joseph1, Y. St-Pierre1, S. Godefroy3, S. J. Elliott4, A. E. Clarke1; 1 McGill University, Montreal, QC, CANADA, 2McMaster University, Hamilton, ON, CANADA, 3Health Canada, Ottawa, ON, CANADA, 4Waterloo University, Waterloo, ON, CANADA. RATIONALE: To identify predictors associated with avoidance of known allergens. METHODS: Individuals reporting physician-diagnosed allergy to peanut, tree-nut, fish, shellfish and/or sesame in a nationwide telephone survey conducted in 2008/9 were asked about avoidance of the food since diagnosis. Multivariate logistic regression performed to identify predictors (education, allergen, characteristics of most severe reaction) associated with avoidance. RESULTS: Of 10,596 households surveyed, 3666 responded, representing 9667 individuals, (35%) of which 208 (2.15% [95% CI, 1.86, 2.44]) reported at least one physician-diagnosed allergy to the above-mentioned foods. 202 of 208 (97%) provided sufficient information to be included in the analysis. Of these, individuals with an allergy to peanut/tree-nut/sesame were less likely to avoid compared to those with fish/shellfish (Odds Ratio (OR) 0.062 [95% CI, 0.025, 0.15]). Individuals who received epinephrine during their most severe reaction were more likely to avoid than those who did not (OR 4.51 [95% CI, 1.70, 12.0]). CONCLUSIONS: We hypothesize that those with fish/shellfish allergy are more able to avoid their known allergen as it is easily identifiable whereas many foods are labeled as containing trace amounts of peanut/ tree-nut/sesame and hence are more difficult to avoid. Those who received epinephrine presumably are better able to appreciate the potential severity of a subsequent reaction and hence were more diligent about avoidance. Given the unpredictability of allergic reactions to peanut/tree-nut/sesame, all allergic individuals, even those with a previous mild reaction, should receive education regarding importance of food avoidance. Additionally, food labels should be clearer so that allergic individuals can easily avoid foods containing peanut/tree-nut/sesame.
914
TUESDAY
Comparison of Cetirizine to Diphenhydramine in the Treatment of Acute Food Allergic Reactions J. H. Park, J. H. Godbold, D. Chung, H. A. Sampson, J. Wang; Mount Sinai Medical Center, New York, NY. RATIONALE: Cetirizine is a second generation antihistamine with a longer duration of action and less sedation than diphenhydramine. While diphenhydramine is traditionally used in the treatment of food allergic reactions, its sedating properties can interfere with the assessment of patients. Therefore, we compared the onset of symptom relief and medication-related sedation of cetirizine and diphenhydramine in the treatment of acute food allergic reactions in patients undergoing oral food challenges. METHODS: This was a randomized, double-blind study of 70 allergic reactions during food challenge (64 patients, 3 to 19 years of age, 35 reactions in each treatment arm). Informed consent was obtained. Upon reacting, patients received either liquid diphenhydramine (1mg/kg) or liquid cetirizine (0.25mg/kg). Other medication was given as indicated for the allergic reaction. Patients were monitored at 10-minute intervals for allergic symptoms and sedation by nursing staff blinded to the medication. RESULTS: The mean time to resolution of hives and pruritus was similar in both groups [42.3 (SD 23.15) min vs 40.8 (SD 22.11) min, and 28.6 (SD 20.54) min vs 31.3 (SD 20.07) min, respectively, for diphenhydramine vs cetirizine (p50.859 for hives and p50.665 for pruritus)]. In the diphenhydramine-treated group, 28.6% experienced sedation as compared to 17.1% for the cetirizine-treated group (difference in sedation of 11.4%, CI -8.4% to 30.2%). No adverse events were observed. CONCLUSIONS: Cetirizine has similar efficacy as compared with diphenhydramine in treating acute food allergic reactions. With the added benefits of longer duration of action and less sedation, cetirizine is a good treatment option for acute food allergic reactions.
911
Role Of Disulfide Bridges In The Proteolytic Susceptibility And Allergenicity Of Ara H 6, A Major Allergen From Peanut B. Guillon1, S. Hazebrouck1, K. Adel-Patient1, E. Paty2, P. Scheinmann2, J. M. Wal1, H. Bernard1; 1INRA, Gif sur Yvette, FRANCE, 2H^opital Necker Enfants Malades, Paris, FRANCE. RATIONALE: Five disulfide (S-S) bridges stabilize the structure of Ara h 6. We investigated the impact of each S-S bridge on Ara h 6 susceptibility to pepsin and trypsin digestion and on its immunoreactivity. METHODS: Progressive deletion of the S-S bridges by substituting alanine for cysteine was performed on a recombinant Ara h 6. Proteolysis by pepsin and trypsin were followed using SDS-PAGE and the peptides produced during digestion were identified by mass spectrometry. Immunoreactivity of the recombinant proteins and their proteolytic fragments was assessed by IgE binding studies using sera from 5 peanut-allergic patients sensitized to Ara h 6. The capacity to induce the degranulation of humanized rat mast cells passively sensitized with human specific IgE was also evaluated. RESULTS: The recombinant Ara h 6 and the mutant lacking the C-terminal (C84-C124) S-S bridge exhibited identical structure to and the same immunoreactivity as the natural counterpart. The loss of an additional S-S bridge slightly decreased the protein immunoreactivity. However, the susceptibility to proteolysis was highly dependant on the S-S bridge deleted. Complete degradation of Ara h 6 by pepsin and trypsin occurred when the central S-S bridges (C26-C58 or C59-C107) were mutated, thus leading to a total loss of allergenicity after digestion. Immunoreactivity of Ara h 6 was conserved only when a heterodimeric structure, characteristic of the 2S albumin, was preserved after digestion. CONCLUSIONS: The central S-S bridges stabilize the protease-resistant core of Ara h 6 and have a major role on its structure and biological properties. The Use of Epinephrine for the Treatment of Initial Allergic Reactions to Peanut M. Ben-Shoshan1, L. Soller2, R. Alizadehfar1, J. Fragapane3, L. Joseph3,4, Y. St. Pierre3, L. Harada5, M. Allen6, A. Clarke3,7; 1McGill University Montreal Children Hospital, Montreal, QC, CANADA, 2Division of Pediatric Allergy and Clinical Immunology, Department of Pediatrics, McGill University Health Center, Montreal, Quebec, Canada, Montreal, QC, CANADA, 3Division of Clinical Epidemiology, Department of Medicine, McGill University Health Center, Montreal, QC, CANADA, 4Departments of Epidemiology and Biostatistics, McGill University, Montreal, QC, CANADA, 5Anaphylaxis Canada, Toronto, ON, CANADA, 6Allergy/Asthma Information Association, Toronto, ON, CANADA, 7Division of Allergy and Clinical Immunology, Department of Medicine, McGill University Health Center, Montreal, QC, CANADA. RATIONALE: To assess the use of epinephrine to treat initial allergic reactions to peanut in health care facilities (HCF). METHODS: Parents of children with an allergist-confirmed peanut allergy recruited from the Montreal Children’s Hospital and from PanCanadian food allergy advocacy associations were queried on the management of the initial allergic reactions. RESULTS: Six hundred twenty-nine individuals reported an initial allergic reaction to peanut. Median age of initial reaction was 1.6 years (IQR, 1.1, 2.6) and 46.1% (95% CI, 42.2, 50.1) were brought to HCFs. Epinephrine was administered to 23.1% (95% CI, 18.4, 28.4) of those brought to HCFs. Among those with moderate/severe reactions, 55.2% (95% CI, 50.5, 59.7) were brought to HCFs, and 24.9% (95% CI, 19.7, 30.7) of these received epinephrine. Epinephrine auto-injector (EAI) was prescribed in 58.0% (95% CI, 51.5, 64.3) of cases brought to HCF. Factors associated with epinephrine treatment in a HCF were the presence of a severe reaction [OR 3.26 (95% CI, 1.72, 6.15)] and a family history of atopy [OR 2.25 (95% CI, 1.20, 4.20)]. Factors associated with EAI prescription were use of epinephrine for the initial reaction: [OR 5.23 (95% CI, 2.39, 11.45)]; living in Quebec: [OR 2.55 (95% CI, 1.43, 4.56)] and calendar year of initial reaction [OR 1.09 95% CI 1.02, 1.16)]. CONCLUSIONS: Our results reveal underuse of epinephrine and low rates of EAI prescriptions in HCFs. Guidelines prompting epinephrine use and prescription to all individuals presenting with a likely allergic reaction to peanut are required.
912
J ALLERGY CLIN IMMUNOL FEBRUARY 2011
913
Food Avoidance Following Physician Diagnosis Of Food Allergy: Results From A Canadian Study L. Soller1, J. Fragapane1, M. Ben-Shoshan1, D. Harrington2, R. Alizadehfar1, L. Joseph1, Y. St-Pierre1, S. Godefroy3, S. J. Elliott4, A. E. Clarke1; 1 McGill University, Montreal, QC, CANADA, 2McMaster University, Hamilton, ON, CANADA, 3Health Canada, Ottawa, ON, CANADA, 4Waterloo University, Waterloo, ON, CANADA. RATIONALE: To identify predictors associated with avoidance of known allergens. METHODS: Individuals reporting physician-diagnosed allergy to peanut, tree-nut, fish, shellfish and/or sesame in a nationwide telephone survey conducted in 2008/9 were asked about avoidance of the food since diagnosis. Multivariate logistic regression performed to identify predictors (education, allergen, characteristics of most severe reaction) associated with avoidance. RESULTS: Of 10,596 households surveyed, 3666 responded, representing 9667 individuals, (35%) of which 208 (2.15% [95% CI, 1.86, 2.44]) reported at least one physician-diagnosed allergy to the above-mentioned foods. 202 of 208 (97%) provided sufficient information to be included in the analysis. Of these, individuals with an allergy to peanut/tree-nut/sesame were less likely to avoid compared to those with fish/shellfish (Odds Ratio (OR) 0.062 [95% CI, 0.025, 0.15]). Individuals who received epinephrine during their most severe reaction were more likely to avoid than those who did not (OR 4.51 [95% CI, 1.70, 12.0]). CONCLUSIONS: We hypothesize that those with fish/shellfish allergy are more able to avoid their known allergen as it is easily identifiable whereas many foods are labeled as containing trace amounts of peanut/ tree-nut/sesame and hence are more difficult to avoid. Those who received epinephrine presumably are better able to appreciate the potential severity of a subsequent reaction and hence were more diligent about avoidance. Given the unpredictability of allergic reactions to peanut/tree-nut/sesame, all allergic individuals, even those with a previous mild reaction, should receive education regarding importance of food avoidance. Additionally, food labels should be clearer so that allergic individuals can easily avoid foods containing peanut/tree-nut/sesame.
914
TUESDAY
Comparison of Cetirizine to Diphenhydramine in the Treatment of Acute Food Allergic Reactions J. H. Park, J. H. Godbold, D. Chung, H. A. Sampson, J. Wang; Mount Sinai Medical Center, New York, NY. RATIONALE: Cetirizine is a second generation antihistamine with a longer duration of action and less sedation than diphenhydramine. While diphenhydramine is traditionally used in the treatment of food allergic reactions, its sedating properties can interfere with the assessment of patients. Therefore, we compared the onset of symptom relief and medication-related sedation of cetirizine and diphenhydramine in the treatment of acute food allergic reactions in patients undergoing oral food challenges. METHODS: This was a randomized, double-blind study of 70 allergic reactions during food challenge (64 patients, 3 to 19 years of age, 35 reactions in each treatment arm). Informed consent was obtained. Upon reacting, patients received either liquid diphenhydramine (1mg/kg) or liquid cetirizine (0.25mg/kg). Other medication was given as indicated for the allergic reaction. Patients were monitored at 10-minute intervals for allergic symptoms and sedation by nursing staff blinded to the medication. RESULTS: The mean time to resolution of hives and pruritus was similar in both groups [42.3 (SD 23.15) min vs 40.8 (SD 22.11) min, and 28.6 (SD 20.54) min vs 31.3 (SD 20.07) min, respectively, for diphenhydramine vs cetirizine (p50.859 for hives and p50.665 for pruritus)]. In the diphenhydramine-treated group, 28.6% experienced sedation as compared to 17.1% for the cetirizine-treated group (difference in sedation of 11.4%, CI -8.4% to 30.2%). No adverse events were observed. CONCLUSIONS: Cetirizine has similar efficacy as compared with diphenhydramine in treating acute food allergic reactions. With the added benefits of longer duration of action and less sedation, cetirizine is a good treatment option for acute food allergic reactions.