title: Genotyping of the cagA gene of Helicobacter pylori on immunohistochemistry with East Asian CagA-specific antibody.
abstract: The cytotoxin-associated antigen A (CagA) of Helicobacter pylori prevalent in East Asian countries, where the mortality rate due to gastric cancer is high, has been reported to be structurally different from that in Western countries, where the gastric cancer mortality rate is relatively low. Based on the structural features of the EPIYA motifs located at the carboxyl terminal of the protein, CagA was subdivided into two types: East Asian CagA and Western CagA. A recent study suggested that immunohistochemistry with anti-East Asian-specific antibody (alpha-EAS Ab), which was specifically immunoreactive with East Asian CagA but not with Western CagA, may be useful for diagnosis of the cagA genotype. To further evaluate the value of this diagnostic method in terms of sensitivity, specificity, and accuracy, 143 gastric biopsy specimens with alpha-EAS Ab were analyzed on immunohistochemistry and compared with the sequencing of the cagA gene. It was found that diagnosis of the cagA genotype of H. pylori on immunohistochemistry using the alpha-EAS Ab was highly sensitive (sensitivity 93.2%) and specific (specificity 72.7%), suggesting that immunohistochemical diagnosis of the cagA genotype is useful for diagnosis of the cagA genotype.
authors.affiliation: Department of Molecular Pathology, Faculty of Medicine, Oita University, Oita, Japan.
authors.forename: Ryoko
authors.initials: R
authors.lastname: Kanada
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Uchida
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Tsukamoto
authors.forename: Lam Tung
authors.initials: LT
authors.lastname: Nguyen
authors.forename: Naoki
authors.initials: N
authors.lastname: Hijiya
authors.forename: Keiko
authors.initials: K
authors.lastname: Matsuura
authors.forename: Masaaki
authors.initials: M
authors.lastname: Kodama
authors.forename: Tadayoshi
authors.initials: T
authors.lastname: Okimoto
authors.forename: Kazunari
authors.initials: K
authors.lastname: Murakami
authors.forename: Toshio
authors.initials: T
authors.lastname: Fujioka
authors.forename: Shigetaka
authors.initials: S
authors.lastname: Yanagisawa
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Moriyama
mesh_terms: D020816:Amino Acid Motifs / Q000235:genetics; D000595:Amino Acid Sequence; D000918:Antibody Specificity; D000942:Antigens, Bacterial / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D015415:Biomarkers / Q000378:metabolism; D005753:Gastric Mucosa / Q000378:metabolism / Q000382:microbiology / Q000473:pathology; D005798:Genes, Bacterial; D005838:Genotype; D016481:Helicobacter Infections / Q000175:diagnosis / Q000378:metabolism / Q000382:microbiology; D016480:Helicobacter pylori / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification; D006801:Humans; D007150:Immunohistochemistry; D008969:Molecular Sequence Data; D011110:Polymorphism, Genetic; D017422:Sequence Analysis, DNA
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D015415:Biomarkers; C080866:cagA protein, Helicobacter pylori