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Where To Prick The Apple For Skin Testing?
96
Release of Soluble Protein from Peanut and Its Adsorption by Activated Charcoal In Vitro and In Vivo R. A. Kopper1, S. Jones2, A. Kim1, T. Van1, C. Yue1, R. M. Helm2; 1Hendrix College, Conway, AR, 2University of Arkansas for Medical Sciences, Little Rock, AR. RATIONALE: Activated charcoal (AC) is being investigated for use in the removal of soluble proteins, including peanut allergens, following the ingestion of peanut by allergic individuals. METHODS: Factors affecting the release of soluble allergenic protein from peanut were determined by incubating chopped peanut in simulated gastric fluid under different conditions. The effect of incubation time, volume, and pH on the rate and extent of protein solubilization were investigated. Adsorption of the released protein onto AC was then optimized in vitro. The results were then confirmed under actual physiological conditions in vivo using a porcine animal model system. RESULTS: Adsorption of protein by AC is enhanced in lower reaction volumes and with longer incubation times. The insoluble peanut particulate matter does not interfere with protein binding to AC but releases a significant amount of additional protein when the pH is raised from 2 to 7 such as when stomach contents are emptied into the intestine. Other protein, lipid, and carbohydrate present compete with the protein allergens for AC binding. Pepsin is adsorbed by AC and loses its proteolytic activity. The ability of AC to bind peanut allergens in vivo was demonstrated in the porcine stomach. CONCLUSIONS: The factors affecting the release of protein allergens from peanut and the ability of AC to bind these allergens in vitro and in vivo was characterized. AC shows promise as a potential supplemental treatment for the accidental ingestion of peanuts by allergic individuals.
97
Where To Prick The Apple For Skin Testing? S. A. van der Werff1, A. E. Dubois1, S. van der Heide1, E. van de Weg2, P. Arens2, B. J. Vlieg-Boerstra1; 1University Medical Center Groningen, University of Groningen, Groningen, Netherlands, 2Plant Research International, Wageningen University and Research Center, Wageningen, Netherlands. RATIONALE: Prick-to-prick skin tests (SPTs) with fresh apple are used to assess sensitisation in subjects with oral allergy symptoms (OAS) to apple. We hypothesized that the location of pricking in the apple influences the outcome of SPT results. Aim: To study differences in SPT results taken from different locations of the apple surface in several apple cultivars. METHODS: In the fall of 2007, 20 adult apple allergic subjects were tested by SPTs with apple material obtained from both the stalk and the middle region of four different apple cultivars: Crisps Pink, Golden Delicious, Elize and Santana. These tests were repeated in the spring of 2008 in 31 subjects before the birch pollen season. Sixteen subjects participated in both test series. In the spring 2008, Santana was replaced by Modi due to the limited availability of Santana. For each apple cultivar, differences between SPTs from both regions were calculated by Wilcoxon Signed Rank test within each test series. Besides, the percentage of negative SPTs (wheal diameter 3 mm) were assessed. RESULTS: SPTs from the stalk region gave significantly greater responses than SPTs from the middle region (p values varying from 0.001 to 0.04), except for Santana (p 5 0.067) and Elize 2008 (p 5 0.228). 5% of SPTs from the middle region were negative, while only 1% of the SPTs from the stalk region were negative. CONCLUSIONS: SPT response is correlated to the location of pricking. Therefore, standardization of the location of pricking is needed. We propose the stalk region as location of choice.
98
Allergen Properties Of Salmon From Landlocked And Anadromous Habitats. Y. Kondo1, J. Ahn1, R. Komatsubara1, I. Tsuge1, T. Yasuda2, A. Urisu1; 1 Fujita Health University, Toyoake, Aichi, Japan, 2Tokyo Suisan Kaisha, Tokyo, Japan. RATIONALE: Salmon and trout are the most widely consumed seafood in Japan and many other countries around the world. Due to the confirmed cases of salmon-induced allergy, the food sanitation law in Japan stipulates salmon as one of the specific food items for which labeling is recommended when used as an ingredient of processed foods. However, trout, the landlocked form of anadromous salmon, is not subject to the allergen-labeling requirements, even though both populations belong to a single species. Since no supporting data have been demonstrated to make a clear discrimination between these two populations in terms of allergenicity, we comparatively examined their allergenic properties using sera from fish allergic patients. METHODS: Oncorhynchus nerka of different habitat types were extracted: kokanee (landlocked) and red salmon (anadromous). Control extracts were derived from four other species. This study focused on the (1) IgE-binding capacity of the fish extracts in patients’ sera (n 5 50), (2) ELISA inhibition test between the kokanee and red salmon (n 5 6), and (3) patterns of IgE-binding bands on the immunoblot analysis. RESULTS: The extracts from kokanee and red salmon showed the highest correlation with each other in terms of the IgE-binding capacity, and showed complete (100%) reciprocal cross-inhibition in the ELISA inhibition test. In the immunoblot analysis, the patterns of IgE-binding bands were slightly different between the two extracts, and these bands gradually disappeared when the patients’ sera were preincubated with the counterpart antigen in a dose-dependent manner. CONCLUSIONS: These results suggest that kokanee salmon has similar allergenic properties to red salmon.
99
Impact of Pancreatic Enzymes on Ovalbumin Excretion in Human Breastmilk. A. Des Roches1, L. Paradis1, M. Abbott2, S. Singer1, J. Paradis1, S. Benrejeb-Godefroy2; 1Hoˆpital Sainte-Justine, Montre´al, QC, Canada, 2Bureau of Chemical Safety, Food Directorate, Health Canada, Ottawa, ON, Canada. RATIONALE: Food allergens could be excreted in human breastmilk. The mothers of food allergic children should completely avoid allergens in their diet during the breastfeeding period. Full compliance of maternal restriction diets is often difficult to obtain. We have examined the usefulness of pancreatic enzymes to maximize the elimination diet of the breastfed children. METHODS: Breastmilk was collected hourly for 8 hours following the ingestion of a whole egg. The procedure was repeated after the ingestion of pancreatic enzymes (Cotazym ECS 20ä) and a whole egg. Detection of ovalbumin in the breastmilk samples was accomplished using a sandwich ELISA method with commercially available reagents. The detection limit of this method varied from 0.8 ng/ml to 3.1 ng/ml of ovalbumin in the breastmilk. RESULTS: The breastmilk from 25 mothers were collected. Ovalbumin was detected in 16 (64%) of these mothers. The level of ovalbumin excretion ranged between 2.1 and 262.1 ng/ml. Ovalbumin excretion was reduced in 69% (11/16) of the excreting mothers. In 64% (7/11) of these mothers, ovalbumin was no longer detectable after the ingestion of pancreatic enzymes. CONCLUSIONS: Pancreatic enzymes are useful to decrease the excretion of ovalbumin in the breastmilk of a significant proportion of mothers.
SATURDAY
Abstracts S29
J ALLERGY CLIN IMMUNOL VOLUME 123, NUMBER 2
Release of Soluble Protein from Peanut and Its Adsorption by Activated Charcoal In Vitro and In Vivo R. A. Kopper1, S. Jones2, A. Kim1, T. Van1, C. Yue1, R. M. Helm2; 1Hendrix College, Conway, AR, 2University of Arkansas for Medical Sciences, Little Rock, AR. RATIONALE: Activated charcoal (AC) is being investigated for use in the removal of soluble proteins, including peanut allergens, following the ingestion of peanut by allergic individuals. METHODS: Factors affecting the release of soluble allergenic protein from peanut were determined by incubating chopped peanut in simulated gastric fluid under different conditions. The effect of incubation time, volume, and pH on the rate and extent of protein solubilization were investigated. Adsorption of the released protein onto AC was then optimized in vitro. The results were then confirmed under actual physiological conditions in vivo using a porcine animal model system. RESULTS: Adsorption of protein by AC is enhanced in lower reaction volumes and with longer incubation times. The insoluble peanut particulate matter does not interfere with protein binding to AC but releases a significant amount of additional protein when the pH is raised from 2 to 7 such as when stomach contents are emptied into the intestine. Other protein, lipid, and carbohydrate present compete with the protein allergens for AC binding. Pepsin is adsorbed by AC and loses its proteolytic activity. The ability of AC to bind peanut allergens in vivo was demonstrated in the porcine stomach. CONCLUSIONS: The factors affecting the release of protein allergens from peanut and the ability of AC to bind these allergens in vitro and in vivo was characterized. AC shows promise as a potential supplemental treatment for the accidental ingestion of peanuts by allergic individuals.
97
Where To Prick The Apple For Skin Testing? S. A. van der Werff1, A. E. Dubois1, S. van der Heide1, E. van de Weg2, P. Arens2, B. J. Vlieg-Boerstra1; 1University Medical Center Groningen, University of Groningen, Groningen, Netherlands, 2Plant Research International, Wageningen University and Research Center, Wageningen, Netherlands. RATIONALE: Prick-to-prick skin tests (SPTs) with fresh apple are used to assess sensitisation in subjects with oral allergy symptoms (OAS) to apple. We hypothesized that the location of pricking in the apple influences the outcome of SPT results. Aim: To study differences in SPT results taken from different locations of the apple surface in several apple cultivars. METHODS: In the fall of 2007, 20 adult apple allergic subjects were tested by SPTs with apple material obtained from both the stalk and the middle region of four different apple cultivars: Crisps Pink, Golden Delicious, Elize and Santana. These tests were repeated in the spring of 2008 in 31 subjects before the birch pollen season. Sixteen subjects participated in both test series. In the spring 2008, Santana was replaced by Modi due to the limited availability of Santana. For each apple cultivar, differences between SPTs from both regions were calculated by Wilcoxon Signed Rank test within each test series. Besides, the percentage of negative SPTs (wheal diameter 3 mm) were assessed. RESULTS: SPTs from the stalk region gave significantly greater responses than SPTs from the middle region (p values varying from 0.001 to 0.04), except for Santana (p 5 0.067) and Elize 2008 (p 5 0.228). 5% of SPTs from the middle region were negative, while only 1% of the SPTs from the stalk region were negative. CONCLUSIONS: SPT response is correlated to the location of pricking. Therefore, standardization of the location of pricking is needed. We propose the stalk region as location of choice.
98
Allergen Properties Of Salmon From Landlocked And Anadromous Habitats. Y. Kondo1, J. Ahn1, R. Komatsubara1, I. Tsuge1, T. Yasuda2, A. Urisu1; 1 Fujita Health University, Toyoake, Aichi, Japan, 2Tokyo Suisan Kaisha, Tokyo, Japan. RATIONALE: Salmon and trout are the most widely consumed seafood in Japan and many other countries around the world. Due to the confirmed cases of salmon-induced allergy, the food sanitation law in Japan stipulates salmon as one of the specific food items for which labeling is recommended when used as an ingredient of processed foods. However, trout, the landlocked form of anadromous salmon, is not subject to the allergen-labeling requirements, even though both populations belong to a single species. Since no supporting data have been demonstrated to make a clear discrimination between these two populations in terms of allergenicity, we comparatively examined their allergenic properties using sera from fish allergic patients. METHODS: Oncorhynchus nerka of different habitat types were extracted: kokanee (landlocked) and red salmon (anadromous). Control extracts were derived from four other species. This study focused on the (1) IgE-binding capacity of the fish extracts in patients’ sera (n 5 50), (2) ELISA inhibition test between the kokanee and red salmon (n 5 6), and (3) patterns of IgE-binding bands on the immunoblot analysis. RESULTS: The extracts from kokanee and red salmon showed the highest correlation with each other in terms of the IgE-binding capacity, and showed complete (100%) reciprocal cross-inhibition in the ELISA inhibition test. In the immunoblot analysis, the patterns of IgE-binding bands were slightly different between the two extracts, and these bands gradually disappeared when the patients’ sera were preincubated with the counterpart antigen in a dose-dependent manner. CONCLUSIONS: These results suggest that kokanee salmon has similar allergenic properties to red salmon.
99
Impact of Pancreatic Enzymes on Ovalbumin Excretion in Human Breastmilk. A. Des Roches1, L. Paradis1, M. Abbott2, S. Singer1, J. Paradis1, S. Benrejeb-Godefroy2; 1Hoˆpital Sainte-Justine, Montre´al, QC, Canada, 2Bureau of Chemical Safety, Food Directorate, Health Canada, Ottawa, ON, Canada. RATIONALE: Food allergens could be excreted in human breastmilk. The mothers of food allergic children should completely avoid allergens in their diet during the breastfeeding period. Full compliance of maternal restriction diets is often difficult to obtain. We have examined the usefulness of pancreatic enzymes to maximize the elimination diet of the breastfed children. METHODS: Breastmilk was collected hourly for 8 hours following the ingestion of a whole egg. The procedure was repeated after the ingestion of pancreatic enzymes (Cotazym ECS 20ä) and a whole egg. Detection of ovalbumin in the breastmilk samples was accomplished using a sandwich ELISA method with commercially available reagents. The detection limit of this method varied from 0.8 ng/ml to 3.1 ng/ml of ovalbumin in the breastmilk. RESULTS: The breastmilk from 25 mothers were collected. Ovalbumin was detected in 16 (64%) of these mothers. The level of ovalbumin excretion ranged between 2.1 and 262.1 ng/ml. Ovalbumin excretion was reduced in 69% (11/16) of the excreting mothers. In 64% (7/11) of these mothers, ovalbumin was no longer detectable after the ingestion of pancreatic enzymes. CONCLUSIONS: Pancreatic enzymes are useful to decrease the excretion of ovalbumin in the breastmilk of a significant proportion of mothers.
SATURDAY
Abstracts S29
J ALLERGY CLIN IMMUNOL VOLUME 123, NUMBER 2