title: Serologic detection of infection with cagA+ Helicobacter pylori strains.
abstract: Approximately 60% of Helicobacter pylori isolates possess the cagA gene and express its 120- to 140-kDa product (CagA). In this study, the cagA gene was detected in H. pylori isolates from 26 (81.3%) of 32 patients with duodenal ulcers (DU), 17 (68.0%) of 25 patients with gastric ulcers, and 23 (59.0%) of 39 patients with nonulcer dyspepsia (NUD). By Western blotting (immunoblotting) with antiserum to CagA, in vitro CagA expression was demonstrated for 95.5% of cagA+ strains compared with 0% of strains lacking cagA. Sera from patients infected with cagA+ strains (n = 66) reacted with recombinant CagA in an enzyme-linked immunosorbent assay to a significantly greater extent than either sera from patients infected with strains lacking cagA (n = 30) or sera from uninfected persons (n = 25) (P < 0.001). A strain lacking cagA was isolated from eight patients who had serum immunoglobulin G antibodies to CagA, which suggests that these patients were infected with multiple strains. Serum immunoglobulin G antibodies to CagA were present in 87.5, 76.0, and 56.4% of patients with DU, gastric ulcers, and NUD, respectively (odds ratio, 5.41; 95% confidence interval, 1.44 to 24.72; P = 0.004 [DU versus NUD]). These data demonstrate an association between infection with cagA+ H. pylori and the presence of duodenal ulceration and indicate that serologic testing is a sensitive method for detecting infection with cagA+ strains.
authors.affiliation: Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232-2605, USA.
authors.forename: T L
authors.initials: TL
authors.lastname: Cover
authors.forename: Y
authors.initials: Y
authors.lastname: Glupczynski
authors.forename: A P
authors.initials: AP
authors.lastname: Lage
authors.forename: A
authors.initials: A
authors.lastname: Burette
authors.forename: M K
authors.initials: MK
authors.lastname: Tummuru
authors.forename: G I
authors.initials: GI
authors.lastname: Perez-Perez
authors.forename: M J
authors.initials: MJ
authors.lastname: Blaser
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000907:Antibodies, Bacterial / Q000097:blood; D000942:Antigens, Bacterial; D001426:Bacterial Proteins / Q000235:genetics* / Q000276:immunology; D004381:Duodenal Ulcer / Q000175:diagnosis / Q000276:immunology / Q000382:microbiology; D005260:Female; D005756:Gastritis / Q000175:diagnosis* / Q000276:immunology / Q000382:microbiology; D005798:Genes, Bacterial; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000276:immunology / Q000382:microbiology; D016480:Helicobacter pylori / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D008875:Middle Aged; D012698:Serologic Tests; D013045:Species Specificity; D013276:Stomach Ulcer / Q000175:diagnosis / Q000276:immunology / Q000382:microbiology
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D007074:Immunoglobulin G; C080866:cagA protein, Helicobacter pylori