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Assessment of Dietary Restrictions in New Referrals to Pediatric Allergy Clinic
Abstracts AB235
J ALLERGY CLIN IMMUNOL VOLUME 127, NUMBER 2
Hemocyanin, Troponin C and Fatty Acid-binding Protein (FABP) May be Cross-reactive Allergens Between Crustaceans, Cockroach and Dust Mites R. Ayuso1, G. Grishina1, M. Pascal2, S. Sanchez-Garcia3, D. Towle4, nez3, H. A. Sampson1; 1Mount Sinai Medical Center, C. Smith4, M. Iba~ 2 New York, NY, Hospital Clinic Barcelona, Barcelona, SPAIN, 3Hospital Universitario Ni~ no Jesus, Madrid, SPAIN, 4MDI Biological Lab, Maine, ME. RATIONALE: There is important cross-reactivity between shrimp, dust mites and cockroach allergens, which may be responsible for non-clinically relevant sensitization. In immunoblot inhibition, other allergens than tropomyosin and arginine kinase appear to be cross-reactive. We aimed to characterize other potential cross-reacting allergens among arthropods. METHODS: Sera from 34 subjects with immediate allergic reactions and elevated serum IgE to shrimp were used for allergen characterization. Shrimp, crab and lobster proteins were separated by SDS-PAGE and tested by immunoblotting. Allergens were identified by MS/MS in gel tryptic digests. cDNA clones from Troponin C, Hemocyanin and FABP were isolated and cloned into expression vectors. Recombinant proteins were used for Dot blot and inhibition assays. RESULTS: Immunoblotting demonstrated IgE-binding to crustacean proteins of 60 kDa, and 15-20 kDa. Tryptic digestion followed by MS/MS analysis identified the proteins as Troponin C, Hemocyanin and FABP. Amplified cDNAs encoding for the three proteins were isolated and sequenced. Open reading frame translation provided the complete amino acid sequence of three potential crustacean allergens. Recombinant Troponin C and Hemocyanin were recognized by shrimp-allergic sera by dot blot. FABP showed very mild recognition by patient’s sera. Dot blot Inhibition assays demonstrated inhibition of recombinant Hemocyanin by cockroach extract and from Troponin C by dust mite extract. CONCLUSIONS: Troponin C and Hemocyanin are characterized as novel crustacean allergens, while the role of FABP still needs to be determined. The cross-reactivity of multiple allergens, including Troponin C and Hemocyanin (and possibly FABP) among arthropods emphasizes the need for a component-based diagnosis of shellfish allergy.
908
Assessment of Dietary Restrictions in New Referrals to Pediatric Allergy Clinic M. Szymanska, Y. Yanishevsky, D. Daly, C. Cullinane, J. Hourihane; University College Cork, Cork, IRELAND. RATIONALE: Many food allergic children have unnecessarily broad dietary restrictions, due to parental or professional uncertainty of their sensitization and clinical allergy profiles. The aim of the study was to assess pre- and post-assessment dietary restrictions in new referrals to allergy clinic. METHODS: Prospective questionnaire review of dietary restrictions filled by parents immediately before allergy clinic and by an experienced allergist immediately after the first allergy assessment. 23 common allergenic foods were assessed. RESULTS: 50 new cases were studied; mean age 5.9 years (range 1-16). 47 patients had dietary restrictions at arrival to the clinic (94%). The main foods avoided were peanut (n532, 64%), brazil (n531, 62%) and walnut (n531, 62%). 37 patients (74%) had dietary restrictions decreased after clinic (p50.0001). In 13 (26%) patients no change was made. 12% of children had no restrictions after clinic compared to 6 before clinic (p50.023). Peanut restrictions did not change (from n532 to n526, p50.3), but in all other nut groups advice to avoid decreased significantly. Shellfish avoidance decreased from 36% to 2% (p50.0001). Soy restrictions changed from 20% to 4% (p50.02). CONCLUSIONS: Dietary restrictions in food allergic patients can be reduced rapidly by professional assessment. Identification of confirmed allergens and appropriate nutritional education are essential for food allergic children and their families.
Localization On Caprine b-casein Of The Epitopes Specifically Recognized By Ige From Patients Allergic To Goat's Milk And Tolerant To Cow's Milk S. Ah-Leung1, S. Tilleul1, 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: Patients allergic to goat’s milk (GM) but tolerant to cow’s milk (CM) display a much higher IgE specificity to caprine caseins than to bovine caseins, especially to the b-casein despite a sequence homology of 90%. We aimed to identify the IgE-binding epitopes of the caprine b-casein involved in this restricted specificity. METHODS: First, b-caseins were subjected to a mild proteolysis by plasmin to generate three peptides: f(1-29), f(29-105/7) and f(106/8-207/9). In a second approach, recombinant goat and bovine caseins were produced in Escherichia coli. Chimeric proteins were generated by substituting domains of the caprine b-casein by the corresponding domains of the bovine b-casein. Immunoreactivity of the different proteins and peptides was assessed by IgE binding studies using sera of 9 GM-allergic patients tolerant to CM and 5 CM-allergic patients. RESULTS: The bovine and caprine b-caseins, either natural or recombinant, or the peptides obtained by proteolysis of both natural b-caseins were similarly recognized by IgE from CM-allergic patients. In contrast, the bovine b-casein and its derived peptides were not recognized by IgE of CM-tolerant patients while the caprine b-casein and its fragments f(29-105/7) and, to a lesser extent, f(106/8-207) were highly immunoreactive. Substitution of the caprine domain 44-88 by the corresponding bovine domain in a chimeric bcasein induced a great loss of immunoreactivity. When the domain 130-177 was additionally substituted, immunoreactivity was abolished CONCLUSIONS: The specificity of the IgE response toward the caprine b-casein in patients allergic to GM but tolerant to CM was mainly directed against epitopes localized on domains 44-88 and 130-177.
909
910
Sensitization to Profilin in Japanese Patients with PollenFood Allergy Syndrome: Its Source of Sensitization and Clinical Relevance Y. Fukutomi1,2, M. Taniguchi1, S. Nakayama3, A. Tanaka3, A. Saito1, H. Yasueda1, T. Nakazawa1, M. Hasegawa1, H. Nakamura2, K. Akiyama1; 1 Clinical Research Center for Allergy and Rheumatology, Sagamihara National Hospital, Sagamihara Kanagawa, JAPAN, 2Department of Environmental and Preventive Medicine, Graduate School of Medical Science, Kanazawa University, Kanazawa, Ishikawa, JAPAN, 3Phadia K.K., Tokyo, JAPAN. RATIONALE: Profilin is a pan-allergen which contributes to IgE cross-sensitization between pollen and plant-derived foods. However, the clinical relevance of profilin as a food allergen is still controversial, and pollen as an allergen source contributing to profilin sensitization has not been established. METHODS: To identify the source pollen causing profilin sensitization and elucidate the clinical relevance of profilin as a food allergen among Japanese population, 46 Japanese patients with pollen-food allergy syndrome were studied in terms of their sensitization to various allergen components using ImmunoCAP ISAC (Phadia). Patients sensitized to Phl p 12, timothy profilin (n517, P1 patients), were compared with those not sensitized to Phl p 12 (n529, P- patients), with respect to cosensitization to other allergen components, types of offending food, number of offending food, and symptoms provoked after eating such foods. RESULTS: P1 patients were more likely than P- patients to be sensitized to Phl p 1 (71% vs 45%, p50.13) and Phl p 5 (47% vs 21%, p50.10), marker allergens of genuine sensitization to grass pollen, whereas the prevalences of sensitization to Bet v 1, Amb a 1, and Art v 1 were not different between the two patient groups. P1 patients were more likely to have allergic symptoms to melon, cucumber, tomato, banana, and orange and had a significantly larger number of offending foods (11.6 vs 5.0, p<0.001) than P- patients. CONCLUSIONS: These findings suggest that, in this study population, the main source of profilin sensitization was grass pollen, and profilin sensitization was related to clinically relevant cross-sensitization to plant-derived foods.
TUESDAY
907
J ALLERGY CLIN IMMUNOL VOLUME 127, NUMBER 2
Hemocyanin, Troponin C and Fatty Acid-binding Protein (FABP) May be Cross-reactive Allergens Between Crustaceans, Cockroach and Dust Mites R. Ayuso1, G. Grishina1, M. Pascal2, S. Sanchez-Garcia3, D. Towle4, nez3, H. A. Sampson1; 1Mount Sinai Medical Center, C. Smith4, M. Iba~ 2 New York, NY, Hospital Clinic Barcelona, Barcelona, SPAIN, 3Hospital Universitario Ni~ no Jesus, Madrid, SPAIN, 4MDI Biological Lab, Maine, ME. RATIONALE: There is important cross-reactivity between shrimp, dust mites and cockroach allergens, which may be responsible for non-clinically relevant sensitization. In immunoblot inhibition, other allergens than tropomyosin and arginine kinase appear to be cross-reactive. We aimed to characterize other potential cross-reacting allergens among arthropods. METHODS: Sera from 34 subjects with immediate allergic reactions and elevated serum IgE to shrimp were used for allergen characterization. Shrimp, crab and lobster proteins were separated by SDS-PAGE and tested by immunoblotting. Allergens were identified by MS/MS in gel tryptic digests. cDNA clones from Troponin C, Hemocyanin and FABP were isolated and cloned into expression vectors. Recombinant proteins were used for Dot blot and inhibition assays. RESULTS: Immunoblotting demonstrated IgE-binding to crustacean proteins of 60 kDa, and 15-20 kDa. Tryptic digestion followed by MS/MS analysis identified the proteins as Troponin C, Hemocyanin and FABP. Amplified cDNAs encoding for the three proteins were isolated and sequenced. Open reading frame translation provided the complete amino acid sequence of three potential crustacean allergens. Recombinant Troponin C and Hemocyanin were recognized by shrimp-allergic sera by dot blot. FABP showed very mild recognition by patient’s sera. Dot blot Inhibition assays demonstrated inhibition of recombinant Hemocyanin by cockroach extract and from Troponin C by dust mite extract. CONCLUSIONS: Troponin C and Hemocyanin are characterized as novel crustacean allergens, while the role of FABP still needs to be determined. The cross-reactivity of multiple allergens, including Troponin C and Hemocyanin (and possibly FABP) among arthropods emphasizes the need for a component-based diagnosis of shellfish allergy.
908
Assessment of Dietary Restrictions in New Referrals to Pediatric Allergy Clinic M. Szymanska, Y. Yanishevsky, D. Daly, C. Cullinane, J. Hourihane; University College Cork, Cork, IRELAND. RATIONALE: Many food allergic children have unnecessarily broad dietary restrictions, due to parental or professional uncertainty of their sensitization and clinical allergy profiles. The aim of the study was to assess pre- and post-assessment dietary restrictions in new referrals to allergy clinic. METHODS: Prospective questionnaire review of dietary restrictions filled by parents immediately before allergy clinic and by an experienced allergist immediately after the first allergy assessment. 23 common allergenic foods were assessed. RESULTS: 50 new cases were studied; mean age 5.9 years (range 1-16). 47 patients had dietary restrictions at arrival to the clinic (94%). The main foods avoided were peanut (n532, 64%), brazil (n531, 62%) and walnut (n531, 62%). 37 patients (74%) had dietary restrictions decreased after clinic (p50.0001). In 13 (26%) patients no change was made. 12% of children had no restrictions after clinic compared to 6 before clinic (p50.023). Peanut restrictions did not change (from n532 to n526, p50.3), but in all other nut groups advice to avoid decreased significantly. Shellfish avoidance decreased from 36% to 2% (p50.0001). Soy restrictions changed from 20% to 4% (p50.02). CONCLUSIONS: Dietary restrictions in food allergic patients can be reduced rapidly by professional assessment. Identification of confirmed allergens and appropriate nutritional education are essential for food allergic children and their families.
Localization On Caprine b-casein Of The Epitopes Specifically Recognized By Ige From Patients Allergic To Goat's Milk And Tolerant To Cow's Milk S. Ah-Leung1, S. Tilleul1, 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: Patients allergic to goat’s milk (GM) but tolerant to cow’s milk (CM) display a much higher IgE specificity to caprine caseins than to bovine caseins, especially to the b-casein despite a sequence homology of 90%. We aimed to identify the IgE-binding epitopes of the caprine b-casein involved in this restricted specificity. METHODS: First, b-caseins were subjected to a mild proteolysis by plasmin to generate three peptides: f(1-29), f(29-105/7) and f(106/8-207/9). In a second approach, recombinant goat and bovine caseins were produced in Escherichia coli. Chimeric proteins were generated by substituting domains of the caprine b-casein by the corresponding domains of the bovine b-casein. Immunoreactivity of the different proteins and peptides was assessed by IgE binding studies using sera of 9 GM-allergic patients tolerant to CM and 5 CM-allergic patients. RESULTS: The bovine and caprine b-caseins, either natural or recombinant, or the peptides obtained by proteolysis of both natural b-caseins were similarly recognized by IgE from CM-allergic patients. In contrast, the bovine b-casein and its derived peptides were not recognized by IgE of CM-tolerant patients while the caprine b-casein and its fragments f(29-105/7) and, to a lesser extent, f(106/8-207) were highly immunoreactive. Substitution of the caprine domain 44-88 by the corresponding bovine domain in a chimeric bcasein induced a great loss of immunoreactivity. When the domain 130-177 was additionally substituted, immunoreactivity was abolished CONCLUSIONS: The specificity of the IgE response toward the caprine b-casein in patients allergic to GM but tolerant to CM was mainly directed against epitopes localized on domains 44-88 and 130-177.
909
910
Sensitization to Profilin in Japanese Patients with PollenFood Allergy Syndrome: Its Source of Sensitization and Clinical Relevance Y. Fukutomi1,2, M. Taniguchi1, S. Nakayama3, A. Tanaka3, A. Saito1, H. Yasueda1, T. Nakazawa1, M. Hasegawa1, H. Nakamura2, K. Akiyama1; 1 Clinical Research Center for Allergy and Rheumatology, Sagamihara National Hospital, Sagamihara Kanagawa, JAPAN, 2Department of Environmental and Preventive Medicine, Graduate School of Medical Science, Kanazawa University, Kanazawa, Ishikawa, JAPAN, 3Phadia K.K., Tokyo, JAPAN. RATIONALE: Profilin is a pan-allergen which contributes to IgE cross-sensitization between pollen and plant-derived foods. However, the clinical relevance of profilin as a food allergen is still controversial, and pollen as an allergen source contributing to profilin sensitization has not been established. METHODS: To identify the source pollen causing profilin sensitization and elucidate the clinical relevance of profilin as a food allergen among Japanese population, 46 Japanese patients with pollen-food allergy syndrome were studied in terms of their sensitization to various allergen components using ImmunoCAP ISAC (Phadia). Patients sensitized to Phl p 12, timothy profilin (n517, P1 patients), were compared with those not sensitized to Phl p 12 (n529, P- patients), with respect to cosensitization to other allergen components, types of offending food, number of offending food, and symptoms provoked after eating such foods. RESULTS: P1 patients were more likely than P- patients to be sensitized to Phl p 1 (71% vs 45%, p50.13) and Phl p 5 (47% vs 21%, p50.10), marker allergens of genuine sensitization to grass pollen, whereas the prevalences of sensitization to Bet v 1, Amb a 1, and Art v 1 were not different between the two patient groups. P1 patients were more likely to have allergic symptoms to melon, cucumber, tomato, banana, and orange and had a significantly larger number of offending foods (11.6 vs 5.0, p<0.001) than P- patients. CONCLUSIONS: These findings suggest that, in this study population, the main source of profilin sensitization was grass pollen, and profilin sensitization was related to clinically relevant cross-sensitization to plant-derived foods.
TUESDAY
907