109A Peanut Allergoid with Increased Safety and MaintainedImmunogenicityH. P. M. van der Kleij1, J. Smit2, H. Sleijster-Selis1, R. van den Hout1, L.Gilmartin3, R. Pieters2, E. Kerkvliet1, S. Koppelman1;1HAL Allergy,Leiden, NETHERLANDS,2Institute for Risk Assessment Sciences, Im-munotoxicology, Utrecht University, Utrecht, NETHERLANDS,3CharlesRiver Laboratories Preclinical Services, Ballina, IRELAND.RATIONALE:Peanutsareoneofthe mostcommonfoodsresponsibleforfood-induced anaphylaxis. A curative treatment is not yet available forpeanut-allergic patients. Therefore, a preparation of Ara h2 and Ara h6,the most potent natural peanut allergens, is being developed forimmunotherapy.METHODS: Ara h2 and Ara h6 were co-purified by extraction from de-fattedpeanutpowderandchemicallymodifiedbyreductionoftheintramo-lecular disulfide bonds and alkylation of the resulting free sulfhydrylgroups of Ara h2 and Ara h6, in some cases followed by modificationwith glutaraldehyde. The allergoid was adsorbed to aluminium hydroxide.The allergen-specific IgE binding activity was measured using an inhibi-tion ELISA. An immunogenicity model was set up in mice to study theinduction of IgG antibodies. In addition, an Ara h2/6-specific allergymodel was developed.RESULTS: The IgE bindingcapacityof the allergoid preparationsin vitrowasreducedby>99%ascomparedtothebindingofthenativepreparation.In an Ara h2/6-specific allergy model, C3H/HeOuJ mice sensitized andchallenged with native Ara h2/6 suffered from anaphylactic shock symp-tomsincludingadecreaseinbodytemperature.Sensitizedmicechallengedwith the modified Ara h2/6 preparation did not develop anaphylactic man-ifestations.Finally,IgGresponsesinimmunizedBALB/cmicewerecross-reactive with the native Ara h2/h6 preparation.CONCLUSIONS: In vivo and in vitro models demonstrated that we havebeencapableofpreparinganallergoidpreparationwithanincreasedsafetyprofilecomparedtoitsnativecounterpartthatisreducedinitsallergenicitybut retained its immunogenicity profile.110Characterization of IgG and IgE Binding to ParvalbuminDerived from Commercially Important Fish SpeciesP. Lee, J. A. Nordlee, S. J. Koppelman, J. L. Baumert, S. L. Taylor; Uni-versity of Nebraska, Lincoln, NE.RATIONALE:Parvalbuminisrecognizedaspan-allergeninfishandfrog.However,previousstudiesdemonstratedthattheIgE-andIgG-bindingpat-ternstoparvalbuminsvarydependingonthefishspecies.Weaimedtouse3anti-parvalbumin IgG and human IgE to investigate the contributingfactors for the binding differences.METHODS: Indirect enzyme-linked immunosorbent assay (ELISA) andIgG immunoblotting were used to determine the reactivity of the polyclo-nal anti-cod parvalbumin antibody, and the commercially-available,monoclonal anti-frog and anti-carp parvalbumin antibodies against rawmuscle extracts of 25 fish species. Additionally, sera from 46 individualswith clinical history offish allergy were analyzed for IgE reactivity to par-valbumin using indirect ELISA. Inhibition ELISAwas performed to deter-mine the effects of heating and calcium on IgG-binding to parvalbumin.RESULTS:The3 IgGantibodiesdemonstratedvaryingspecificityfor dif-ferentfishspecies.Polyclonalanti-codparvalbuminantibodyshowedreac-tivity to a wider range of species, whereas the monoclonal anti-frogparvalbumin antibody showed the least cross-reactivity. The binding ofthe 3 IgG antibodies to parvalbumin was unaffected by heating, butthe ab-sence of calcium abolished the binding. IgE reactivity to cod parvalbuminor cod extracts were observed in >50% of individual’s sera, whereas<0.1% of the sera showed reactivity to tuna and swordfish extracts. BothIgG and IgE antibodies showed low reactivity to tuna and swordfish thatare apparently deficient in parvalbumin.CONCLUSIONS: These results suggested that the antibodies specificityto parvalbumins in various fish species is associated with the parvalbuminexpression, its structural conformation, and the primary structure of anti-genic determinations on parvalbumin.111Possible Causes Of New Onset Food Allergies In AdultPatientsP. Amin, S. Mithani, P. Ponda; North Shore Long Island Jewish HealthSystem, Manhasset, NY.RATIONALE: Although prevalence of adult food allergies is increasing,demographic characteristics and specific mechanisms of adverse foodreactions in adults is lacking. Food triggered cellular and IgE-mediatedresponsescancauseaninflammatorycascaderesultinginclinicalmanifes-tations of food hypersensitivity. Since infectious pathogens also cause in-flammatory responses, it is possible that an infection may subsequentlypredispose individuals to develop immunological intolerance to ingestedfood proteins. In this study we sought to determine if adult patients withnew onset food allergy are more likely to have antecedent systemic or en-teric infections.METHODS: A retrospective analysis of medical records and telephoneinterview of patients age >_ 18 years seen at a large academic centerbetween 2000-2010 with diagnosis codes V15.01-V15.05, 995.6-7,995.60-69, or 693.1 was performed. Adult patients diagnosed with firsttime food allergy were included in our study.RESULTS:Twenty six patients metthe above criteriawithan average ageof 49 6 17.7 years. Four percent of the subjects reported a viral infectionantecedenttothedevelopmentofanallergicreaction,31%reportedhavinga new onset foodreaction to shellfish, 27% to fish, 12% to peanuts, and 8%to treenuts.19% of the subjects self reported a new reactionto rice, apples,cantaloupe, or strawberries. 27 % of the subjects self reported concurrentallergic rhinitis.CONCLUSIONS: Although the data about patient characteristics andcausative foods of new onset adult food allergy is revealing, a prospectivestudywouldbetteraddresstherelationshipbetweenantecedentviralillnessand the development of food allergy in adults.112The Role of Breast Milk Immunoglobulins in the Developmentof Oral Tolerance in a Murine Model of Peanut AllergyK. M. Jarvinen, I. Lopez-Exposito, A. E. Seppo, Y. Song, X. Li; MountSinai School of Medicine, New York, NY.RATIONALE: Role of maternal peanut (PN) avoidance during preg-nancy/lactation in prevention of allergy in the offspring is controversial.Using a mouse model we have previously shown that maternal ingestionofPNindosesbelowtheclinicalthresholdthroughoutpregnancy/lactationwas sufficient to prevent PN-induced anaphylaxis in offspring born to PN-sensitized mothers. Protected offspring had higher levels of PN-specificIgG2a antibodyand lower ratio of PN-IgG1 to IgG2a, reflecting the mater-nal serum concentrations. The mechanism of this protection is unknown,although transfer of immunoglobulins either through placenta or via mu-rine milk may play a role.METHODS:Utilizingamousemilkingmachine,milkfrommothersof10to 21-day-old pups was collected from PN-sensitized mothers who contin-ued feeding a low dose of PN and from thosewho stopped feeding PN dur-ing pregnancy/lactation, and from naive mothers, n53/group. PN-specificIgG1, IgG2a and IgA levels in milk were measured using ELISA.RESULTS: Higher levels of PN-specific IgA and lower ratio of PN-spe-cific IgG1 to IgG2a were detected in milk from mothers who continuedfeeding PN throughout pregnancy/lactation than in those who stoppedfeeding PN during the same time period or in naive mothers (p<0.05).CONCLUSIONS: Higher levels of antigen-specific IgA and IgG2a arepresent in milk from mothers who fed peanut throughout pregnancy/lacta-tion. Their pups were protected from peanut-induced anaphylaxis. Theseimmunoglobulins together with peanut antigen in the milk may contributeto the development of antigen-specific oral tolerance in their offspring,which is not seen in those offspring born to mothers avoiding peanut.J ALLERGY CLIN IMMUNOLFEBRUARY 2011AB32 AbstractsSATURDAY
