title: IgG antibody titer against Helicobacter pylori correlates with presence of cytotoxin associated gene A-positive H. pylori strains.
abstract: The level of the IgG antibody titer against Helicobacter pylori correlates with the severity of gastritis. H. pylori strains can harbor the so-called pathogenicity island, containing the cytotoxin associated gene (cagA). Since cagA-positive strains are more virulent it can be postulated that the gastritis will be more severe and hence the IgG antibody titer higher. In a cross-sectional study the correlation of IgG antibody titer and cagA status was studied from patients undergoing upper gastrointestinal endoscopy. Biopsy specimens were obtained to determine the H. pylori status. In addition a serum sample was taken for detection of IgG antibodies against H. pylori as well as CagA. A total of 290 patients positive for IgG antibodies against H. pylori were included. Of these 153 were cagA-positive and 137 were cagA-negative. The mean IgG antibody titer was significantly higher in cagA-positive patients compared to cagA-negatives, 0.75 (S.D. 0.22) versus 0.69 (S.D. 0.24) (P=0.033). It is concluded that the IgG antibody titer is significantly higher in patients harboring cagA-positive H. pylori strains. However, in daily practice the level in IgG antibody titer cannot predict whether or not an individual carries a cagA-positive H. pylori strain since major overlap in IgG antibody titer between cagA-positive and cagA-negative patients is present.
authors.affiliation: Department of Internal Medicine, Ziekenhuis De Heel, P.O. Box 210, 1500 EE, Zaandam, The Netherlands. r.loffeld@chello.nl
authors.forename: R J
authors.initials: RJ
authors.lastname: Loffeld
authors.forename: B F
authors.initials: BF
authors.lastname: Werdmuller
authors.forename: J G
authors.initials: JG
authors.lastname: Kusters
authors.forename: E J
authors.initials: EJ
authors.lastname: Kuipers
mesh_terms: D000328:Adult; D000368:Aged; D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial; D001426:Bacterial Proteins / Q000235:genetics; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D016481:Helicobacter Infections / Q000276:immunology / Q000382:microbiology*; D016480:Helicobacter pylori / Q000276:immunology* / Q000472:pathogenicity; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008875:Middle Aged; D014774:Virulence
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D007074:Immunoglobulin G; C080866:cagA protein, Helicobacter pylori