日本質量分析学会 第66回質量分析総合討論会

Program

Oral Sessions

Day 4, May 18(Fri.) 13:00-13:10 Room A (OrBit Hall)

Development of ELISA assay by eiptope mapping of CagA protein recognized by antibodies in sear for the prevention of Japanese children from chronic infection of Helicobacter pylori

(1Tokuyama Ishikai Hosp., 2DENKA SEIKEN Co. Ltd., 3Tokuyama ishikai Hosp., 4Tanimura Clinic for Paediatrics)
oKazuyuki Nakamura1, Takamichi Takahashi2, Toshiko Fujii3, Satoshi Tanimura4

Chronic infection with East-Asian strains of pathogenic bacteria of Helicobacter pylori (Hp) is a risk factor for not only atrophic gastritis causing gastric cancer in adult but also idiopathic thrombocytopenic purpura or iron deficient anemia in children. An ELISA assay with protein antigenic epitopes of cytotoxin associated gene A (CagA) can be a powerful tool for the diagnosis of Hp infection to prevent chronic infection. Those epitopes were identified by catalogue antigenic proteins of a Japanese strain CPY2052 by two-dimensional electrophoresis followed by immunoblot and LC-MS/MS analysis. Each of the major epitopes of RDLEDKLWAKGLSpQEANK and QKITDKVDNLNQAVSETKL determined by peptide/protein-combined array chip method was found to contain amino acid residues in domain II and III unique to the East-Asian strains of Hp, respectively. (PLoS One. 2014 9(8) e104611) We developed a new ELISA assay using synthetic peptides mimicry of those major epitopes recognized by antibodies in sera and examined the availability of ELIA assay with sear from 225 children of 0-12 y-o in the comparison with a commercially available method of H. pylori-Latex SEIKEN (No. 22800EZX00031000). The rate of infection with Hp was also estimated by H. pylori-Latex SEIKEN with sera from 890 children living in Shunan area to be 1.24%.