Improvement in quality of life following peanut oral immunotherapy in a paediatric population at the Cambridge Peanut Allergy Clinic

Abstract

Shrimp allergy is the second most common food allergy in the U.S.A., affecting up to 1.2% of the pediatric population. Oral immunotherapy (OIT) to food allergy decreases the threshold of clinical reactivity to the specific food. Given the risk of clinical reactions to shrimp allergen with accidental exposures, shrimp OIT may be an effective treatment. Identification of the appropriate OIT product, major shrimp allergen, tropomyosin (Pen a 1) is critical. METHODS: Identification and characterization in a shrimp OIT product of major shrimp allergen tropomyosin (Pen a 1), compared to placebo, oat. Evaluation was made by SDS-PAGE and mass spectrometry analysis performed with digested peptides utilizing nanoHPLC-Q Exactive Mass Spectrometer. Proteome Discoverer1.4 interface with Mascot algorithm utilized to identify recovered peptides. Imunological analysis was made by western blot with anti-shrimp tropomyosin. RESULTS: SDS-PAGE gel identified shrimp tropomyosin at 37kD in the OIT shrimp but not oat product. The tropomyosin database was generated from NCBI database by selecting proteins which have tropomyosin in protein description regardless taxa (283 entries). In the oat sample, two shrimp tropomyosin peptides were identified. Data indicated,based on the area under the curve, oat has 0.01% of tropomyosin concentration compared to shrimp. Recovered tropomyosin peptides from oat may be due to contamination of insects around oat grains. Western blot analysis indicated exclusive signal of tropomyosin from the shrimp sample. CONCLUSIONS: Identification and quantification of Pen a 1 from a potential shrimp OIT product resulted in the confirmation of this product to be a potential candidate for OIT in shrimp allergy.