Shrimp Allergic Patients Research Articles

Effect of high intensity ultrasound on the allergenicity of shrimp

The tropomyosin fraction of shrimp proteins is potentially responsible for allergic reaction in individuals with genetic predisposition to allergy. However, there are no efficient and safe methods to reduce its allergenicity. High intensity ultrasound is known to change the structure of proteins. This study is aimed at assessing high intensity ultrasound's effect on the allergenicity of shrimp allergen. Shrimp and purified shrimp allergen were treated with high intensity ultrasound for 30-180 min. Extracts of treated samples were analyzed by enzyme-linked immunosorbent assay (ELISA) with pool serum of shrimp allergy patients and polyclonal anti-allergen antibodies and by immunoblotting after polyacrylamide gel electrophoresis. Shrimp treated with high intensity ultrasound showed a decrease in allergenicity measured with ELISA. A linear relationship between the immune response induced by treated shrimp allergen and the applied treatment time was observed. The decrease in allergenicity was confirmed by immunoblot assays with shrimp allergic patients serum. Allergenicity of shrimp allergen extracted from treated shrimp was higher than that of purified shrimp allergen with the same treatment time. Gel-filtration HPLC was applied for analysis of shrimp allergen after treatment with high intensity ultrasound. Some fractions were appeared with increasing treatment time. The results suggested that high intensity ultrasound could be used to reduce the allergenicity of shrimp.

Reduction of allergenic properties of shrimp (Penaeus Vannamei) allergens by high intensity ultrasound

The tropomyosin fraction of shrimp proteins is potentially responsible for an allergic reaction in individuals with a genetic predisposition to allergy. However, there are no efficient and safe methods to reduce its allergenicity. High-intensity ultrasound is known to change the structure of proteins. The aim of this study was to assess the effect of high-intensity ultrasound on the IgE-binding capacity of shrimp protein extracts (PE) and of major shrimp allergen Pen a 1(tropomyosin). Peeled shrimp (Penaeus vannamei) muscle was sealed in a plastic bag and treated with high-intensity ultrasound (30 Hz, 800 W) for 1.5 h at 0 and 50 °C, respectively; others were treated with boiling water for 15 min. Then PE and Pen a 1 were made with treated shrimp muscle. The allergenicity of PE and purified allergen from different-treated shrimp were analyzed by the enzyme allergosorbent test (EAST) and competitive inhibition ELISA (Ci-ELISA) using sera of 15 shrimp-allergic patients. PE from high-intensity ultrasonic treatment at 50 °C (treated 2) shrimp was 2.2-fold, 2.5-fold lower respectively than that of untreated shrimp and high-intensity ultrasonic treatment at 0 °C (treated 1) shrimp. While PE from heated (treated 3) shrimp was 1.2-fold lower than that of untreated shrimp. The (Concentration of the different-treated sample that inhibit 50% of the IgE binding to coated untreated sample) IC50 ratios of Pen a 1 prepared from treated 2 shrimp, treated 1 shrimp and treated 3 shrimp to untreated shrimp were 1/15, 1/1.1 and 1/1, respectively. The results suggest that high-intensity ultrasound at 50 °C may reduce the allergenicity of shrimp.

Proteomics and immunological analysis of a novel shrimp allergen, Pen m 2.

Shellfish are a common cause of adverse food reactions in hypersensitive individuals and shrimp is one of the most frequently reported causes of allergic reactions. A novel allergen from Penaeus monodon, designated Pen m 2, was identified by two-dimensional immunoblotting using sera from subjects with shrimp allergy, followed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry analysis of the peptide digest. This novel allergen was then cloned and the amino acid sequence deduced from the cDNA sequence. The cloned cDNA encoded a 356-aa protein with an acetylated N terminus at Ala2, identified by postsource decay analysis. Comparison of the Pen m 2 sequence with known protein sequences revealed extensive similarity with arginine kinase (EC 2.7.3.3) from crustaceans. Pen m 2 was purified by anion exchange chromatography and shown to have arginine kinase activity and to react with serum IgE from shrimp allergic patients and induce immediate type skin reactions in sensitized patients. Using Pen m 2-specific antisera and polyclonal sera from shrimp-sensitive subjects in a competitive ELISA inhibition assay, Pen m 2 was identified as a novel cross-reactive Crustacea allergen. This novel allergen could be useful in allergy diagnosis and in the treatment of Crustacea-derived allergic disorders.

Identification of a cross-reactive allergen (presumably tropomyosin) in shrimp, mite and insects.

A monoclonal antibody to Dermatophagoides pteronyssinus is described that cross-reacts with an IgE-binding antigen present in insects, Crustacea (e.g. shrimp) and other invertebrates. By means of sodium dodecyl sulfate-polyacrylamide gel electrophoresis, gel filtration and immunofluorescence it was shown that this monoclonal antibody presumably recognizes tropomyosin. Tropomyosin was shown to be involved in cross-reactivity between mite, shrimp and insects in shrimp-allergic patients.