Desensitization by Sublingual Immunotherapy for Crustacean Allergy

Desensitization by Sublingual Immunotherapy for Crustacean Allergy

AB88 Abstracts 316 SUNDAY Characterization of Apple Allergy in A Mediterranean Population Marıa Jose Torres, MD, PhD1, Francisca Gomez, MD, PhD1...

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AB88 Abstracts

316

SUNDAY

Characterization of Apple Allergy in A Mediterranean Population Marıa Jose Torres, MD, PhD1, Francisca Gomez, MD, PhD1, Ana Aranda, PhD2, Cristobalina Mayorga, PhD3,4, Ignacio Garcia, MD, PhD1, Araceli Diaz-Perales, PhD5, Natalia Blanca-Lopez, MD, PhD6, Elena Seoane, MD, PhD6, Arantxa Palacin, PhD5, Maria Garrido, PhD5, Stefan Vieths, PhD7, Miguel Blanca, MD, PhD1; 1Allergy Service, Carlos Haya Hospital, Malaga, Spain, 2Research Laboratory, Carlos Haya Hospital-FIMABIS, Malaga, Spain, 3Research Laboratory, Carlos Haya Hospital, Malaga, Spain, 4Pediatric Service, Carlos Haya Hospital, Malaga, Spain, 5Biotechnology Department, Center for Plant Biotechnology and Genomics, Madrid, Spain, 6Allergy Service, Infanta Leonor Hospital, Madrid, Spain, 7Paul-Ehrlich-Institut, Langen, Germany. RATIONALE: Studies from different populations have shown two different clinical entities in apple allergy, oral allergy syndrome (OAS) and systemic symptoms, reflecting different patterns of allergen sensitization. We analyzed the pattern of sensitization to a wide panel of inhalant, fruits, nuts allergens and different components (Mald1, Mald2, rMald3, rMald4, rPrup3, rBetv1 and Phold2) in a population of Mediterranean patients allergic to apple. METHODS: Patients (N581) with a clinical history of allergy to apple confirmed by positive skin prick test (SPT) and double blind placebo controlled food challenge (DBPCFC) were included. SPT and ELISA were done with a panel of inhalant, fruit, nut allergens and to the different components detailed above. ELISA inhibition studies were done for analyzing pattern of sensitization. RESULTS: Thirty-five cases (43.2%) had OAS and 46 (56.8%) systemic symptoms. SPT showed higher positive results with peach, cherry and hazelnut in those with systemic symptoms. ELISA showed significantly higher percentage of positivity in patients (OAS and systemic) when compared to controls for rMald3, rMald4, rPrup3, Olive, Birch and Tymothy grass; between those with systemic symptoms and controls for hazelnut; and between OAS and controls for Betv1. Three different patterns of recognition were detected: positive to LTP (rMald3 and/or rPrup3), to profilin (rMald4 and/or Phold2) or to both, being the latter most frequently detected in those with systemic symptoms. CONCLUSIONS: This study indicates that when analyzing a big population with apple allergy different patterns of sensitization may appear with those with systemic symptoms mainly induced by LTP.

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Food Specific IgE Levels in Children Should Be Interpreted in Context of Total IgE Tara J. Federly, MD1,2, Bridgette L. Jones, MD, FAAAAI1, Hongying Dai, PhD1, Chitra Dinakar, MD, FAAAAI1,2; 1Children’s Mercy Hospital & Clinics, Kansas City, MO, 2University of Missouri-Kansas City. RATIONALE: Food specific IgE (fsIgE) cut-points are used in the evaluation of food allergies. Concomitant measurement of total IgE (tIgE) is traditionally not performed. We have anecdotally observed elevations in fsIgE levels mirroring tIgE increases, confounding accurate interpretation. We aimed to determine if a) changes in tIgE correlated with fsIgE and b) predictions of fsIgE could be formulated based on tIgE. METHODS: Subjects were children <18 years of age who had both tIgE and fsIgE (egg, n5136; milk, n5123; peanut, n5201; soy, n555) obtained _1 occasion between 1/2008 and 2/2011 during clinical simultaneously on > evaluation. After IRB approval, log-transformed (ln) tIgE and fsIgE levels were retrospectively analyzed using univariate and multivariate regression models to assess associations and to predict fsIgE using tIgE and other covariates. RESULTS: Soy IgE levels were strongly correlated (Pearson correlation coefficient rho50.85, p<0.0001), while egg, milk and peanut IgE levels were moderately correlated (rho50.69, 0.69, and 0.66 respectively, p<0.0001) with tIgE levels. A one unit increase in ln(tIgE) was significantly associated with unit increases in ln(egg IgE) (0.77), ln(milk IgE) (0.84), ln(peanut IgE) (0.87) and ln(soy IgE) (0.89) (p<0.0001). The ln(tIgE)-based univariate model could predict fsIgE in the validation data (p<0.0001) with strong (soy) and moderate (egg, milk and peanut) predictive ability. CONCLUSIONS: Our study shows significant and parallel relationships between total IgE and food-specific IgE levels to egg, milk, peanut and soy. It underscores the importance of examining fsIgE levels in context of tIgE while making diagnostic and management decisions in children with food allergies.

J ALLERGY CLIN IMMUNOL FEBRUARY 2013

318

Threshold Dose for Shrimp: A Risk Characterization Based On Objective Reactions in Clinical Studies Julie A. Nordlee, MS1, Benjamin C. Remington, BS1, Barbara K. Ballmer-Weber, MD2, Samuel B. Lehrer, PhD, FAAAAI3, Joe L. Baumert, PhD1, Steve L. Taylor, PhD1; 1Food Allergy Research and Resource Program, University of Nebraska-Lincoln, Lincoln, NE, 2University Hospital of Zurich, Zurich, Switzerland, 3Tulane University Medical Center, New Orleans, LA. RATIONALE: A DBPCFC of shrimp-allergic adults was conducted to obtain individual threshold doses. Results of this study and published research were combined and a population threshold for shrimp was determined from dose-distribution modeling. METHODS: Twenty-four shrimp allergic individuals were orally challenged with increasing doses of brown shrimp (Penaeus aztecus). The shrimp was incorporated into a seasoned ground beef matrix and cooked. Seven doses ranging from 100 micrograms to 4 g shrimp were randomly interspersed with three placebo doses. If objective reactions were not observed, open challenges of 4 g and 16 g were given. The population threshold was estimated using interval-censoring survival analysis and the log-normal, log-logistic, and Weibull statistical distributions. The estimated population threshold for shrimp used data from subjects who experienced objective allergic reactions to shrimp in this DBPCFC as well as from published clinical research. RESULTS: A total of 48 shrimp-allergic individuals with objective symptoms contributed threshold data. The most sensitive two individuals reacted at 2.5 mg shrimp protein (11 mg whole shrimp) with mild objective symptoms. The ED05’s (the dose predicted to provoke reactions in 5% of the shrimp-allergic population) were respectively 73.6, 127, and 110 mg (shrimp protein) for the log-normal, log-logistic, and Weibull distributions, respectively. The ED05, ED10, and ED50 estimates for shrimp were significantly higher than estimates determined for peanut, milk, and egg. CONCLUSIONS: The shrimp-allergic population seems to have a higher threshold compared to other populations for other food allergens. Additional shrimp challenges should be done to confirm these initial results.

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Desensitization by Sublingual Immunotherapy for Crustacean Allergy Maged Refaat, MD1, Khalid El-Damhougy, MD2, Adham Sadiq, MD2, Mohamed Attia, PhD1, Mabrouk Mabrouk2; 1Department of Allergy and Clinical immunology,Ain Shams university, Cairo, Egypt, 2Department of Zoology and Entomology, Faculty of Science, Al-Azhar university, Egypt. RATIONALE: Crustaceans, such as shrimp, crab, crayfish and lobster, play important role in human nutrition; they also can be important causes of severe acute hypersensitivity reactions. For patients diagnosed with a crustacean allergy, strict avoidance is the only proven therapy, highlighting the need for more specific treatment. Our aim was to evaluate the efficacy and tolerance of sublingual shrimp immunotherapy in Egyptian patients allergic to shrimp. METHODS: A randomized ,double blind, placebo-controlled study investigating 60 patients (subdivided to 3 groups 28 urticarial, 18 rhinitis and 14 asthmatic patients)allergic to shrimp, Inclusion criteria were a history of shrimp allergy and positive skin prick test to crude shrimp extract from two species (Penaeussemisulcatus and Metapenaeusstebbingi) at allergy and clinical immunology unit, in-Shams Hospitals. They underwent immunotherapy with extract of shrimp species, administered sublingually (SLIT). Skin tests, measurement of specific IgE, IgG4 for shrimp allergen on the start and 6 months after immunotherapy, as compared to placebo, were performed. RESULTS: Results obtained up to 6 months after start of treatment achieved a significant reduction of allergic symptoms in daily life compared to placebo (p<0.001) . The clinical response of the patients was correlated with a highly significant decline in specific IgE test (p<0.001) and with increased IgG4 (p<0.001). A subgroup analysis of patients revealed that most responsive desensitized group was rhinitis group followed by urticarial group. CONCLUSIONS: Sublingual immunotherapy for shrimp allergy was safe, well tolerated and efficacious, gave a good results especially in the treatment of patients with allergic rhinitis.