title: Immunohistochemical diagnosis of the cagA-gene genotype of Helicobacter pylori with anti-East Asian CagA-specific antibody.
abstract: Cytotoxin-associated antigen A (CagA) protein produced by Helicobacter pylori is proposed to be associated with the pathogenesis of gastric cancer as well as gastritis and gastroduodenal ulcer. It has been reported that the CagA of H. pylori widespread in East Asian countries, where the mortality rate due to gastric cancer is high, is structurally different from that in Western countries, where the gastric cancer mortality rate is relatively low. In this study, we generated an antibody, East Asian CagA-specific antibody (alpha-EAS Ab), which is specifically immunoreactive with East Asian CagA but not with Western CagA. The CagA was immunohistochemically detected at the surface of the gastric mucosa. Interestingly, positive immunoreactivity was also detected in the nucleus and cytoplasm of the infected gastric epithelium, suggesting that CagA may play some pathogenic role in both the nucleus and cytoplasm. Immunohistochemistry of 47 gastric biopsy specimens detected East Asian CagA-positive H. pylori in 43 cases. In 46 of the 47 cases examined, the data obtained by immunohistochemistry were completely consistent with those obtained by sequencing of the cagA gene of the isolated strain, suggesting that our immunohistochemical method is reliable and useful for diagnosis of the cagA genotype.
authors.affiliation: Department of Molecular Pathology, Oita University, Yufu-city, Oita 879-5593, Japan.
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Uchida
authors.forename: Ryoko
authors.initials: R
authors.lastname: Kanada
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Tsukamoto
authors.forename: Naoki
authors.initials: N
authors.lastname: Hijiya
authors.forename: Keiko
authors.initials: K
authors.lastname: Matsuura
authors.forename: Shinji
authors.initials: S
authors.lastname: Yano
authors.forename: Shigeo
authors.initials: S
authors.lastname: Yokoyama
authors.forename: Tetsuko
authors.initials: T
authors.lastname: Kishida
authors.forename: Masaaki
authors.initials: M
authors.lastname: Kodama
authors.forename: Kazunari
authors.initials: K
authors.lastname: Murakami
authors.forename: Toshio
authors.initials: T
authors.lastname: Fujioka
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Moriyama
mesh_terms: D000595:Amino Acid Sequence; D000907:Antibodies, Bacterial; D000918:Antibody Specificity; D000942:Antigens, Bacterial / Q000235:genetics / Q000276:immunology*; D001208:Asia; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology*; D005753:Gastric Mucosa / Q000382:microbiology; D005798:Genes, Bacterial; D005838:Genotype; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000276:immunology; D016480:Helicobacter pylori / Q000235:genetics / Q000302:isolation & purification*; D007150:Immunohistochemistry; D008969:Molecular Sequence Data; D010437:Peptic Ulcer / Q000382:microbiology; D012698:Serologic Tests / Q000379:methods*; D012703:Serotyping / Q000379:methods; D013274:Stomach Neoplasms / Q000382:microbiology
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C080866:cagA protein, Helicobacter pylori