title: Responses of endoscopy patients in Ladakh, India, to Helicobacter pylori whole-cell and Cag A antigens.
abstract: Although Helicobacter pylori is a cosmopolitan colonizer of the human stomach, the responses among persons in remote populations from whom H. pylori was cultured have not been studied. We report on studies of 189 persons in the Ladakh region of India in whom serum immunoglobulin G responses to H. pylori whole-cell and Cag A antigens were measured. H. pylori was isolated from 68 of these patients. An H. pylori whole-cell antigen derived from Ladakhi strains outperformed a similar antigen from U.S. strains, as determined by antigen-specific enzyme-linked immunosorbent assays. In total, 95% of the population was seropositive, including individuals responding only to the Cag A antigen. Correlation with culture results showed that these were true positives and, therefore, that the H. pylori whole-cell serology was falsely negative in some cases. In addition to establishing a collection of H. pylori isolates from a remote area in the world, we show that use of H. pylori whole-cell and Cag A serology together increases the sensitivity for the detection of colonization.
authors.affiliation: Division of Infectious Diseases, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
authors.forename: Judith
authors.initials: J
authors.lastname: Romero-Gallo
authors.forename: Guillermo I
authors.initials: GI
authors.lastname: Pérez-Pérez
authors.forename: Richard P
authors.initials: RP
authors.lastname: Novick
authors.forename: Patrick
authors.initials: P
authors.lastname: Kamath
authors.forename: Tsering
authors.initials: T
authors.lastname: Norbu
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Blaser
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial / Q000276:immunology; D001426:Bacterial Proteins / Q000276:immunology*; D002648:Child; D016099:Endoscopy, Gastrointestinal; D005260:Female; D016480:Helicobacter pylori / Q000276:immunology* / Q000302:isolation & purification; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D007074:Immunoglobulin G; C080866:cagA protein, Helicobacter pylori