Extraction of Crab (Scylla Serrata) Myofibrillar and Sarcoplasmic Proteins to Create a Skin Prick Test Reagent for Crab Allergy Diagnosis

The major and minor allergens in fish and shellfish that have been identified are broadly spread in the myofibrillar and sarcoplasmic proteins. This study aimed to create a skin prick test reagent of crab myofibrillar and sarcoplasmic proteins to improve sensitivity and specificity diagnosis of allergy. Myofibrillar protein fraction was composed of 19 protein bands with the molecular weights of 9.6-111.6 kDa and sarcoplasmic protein fraction was composed of 19 protein bands with the molecular weights of 9.5-104.6 kDa. The allergenic myofibrillar protein has the molecular weights of 13.9-155.4 kDa while the allergenic sarcoplasmic protein has the molecular weights of 8.4-129.4 kDa. Crab myofibrillar and sarcoplasmic reagents met the requirements of the European Pharmacopoeia Monograph on Allergen Products 7 (2010:1063) for the parameters of moisture content, protein content, sterility and microbiology. A skin prick test to the respondents indicated that the sensitivity value of crab myofibrillar reagent was 85% and crab sarcoplasmic reagent was 69% with a negative error rate for each myofibrillar and sarcoplasmic reagents was 15% and 31%, respectively. The result diagnosis of crab myofibrillar and sarcoplasmic sensitivities would generate sensitivity value at 100%. The separation of crab proteins into myofibrils and sarcoplasm for skin prick test could improve its sensitivity value and lowered the negative misdiagnosis. The specificity of each myofibrillar and sarcoplasmic proteins was 100% with an error rate of positive diagnosis occurrence at 0%.