title: Helicobacter pylori infection, anti-cagA antibodies and peptic ulcer: a case-control study in Italy.
abstract: OBJECTIVE
  To evaluate the association between infection with specific strains of Helicobacter pylori and peptic ulcer in patients referred for upper gastrointestinal endoscopy.
  
  
  METHODS
  One thousand, six hundred and twenty-six consecutive dyspeptic patients, referred to one Endoscopy Unit in Bologna, Italy, were enrolled. For each participant, a blood sample was obtained for the measurement of distinct immunoglobulin G antibodies against H. pylori lysate and cytotoxin associated gene A (cagA). A case-control study included the whole series: patients diagnosed with duodenal (n=275) or gastric (n=71) ulcer were identified and independently compared with controls with non-ulcer dyspepsia (n=1280).
  
  
  RESULTS
  H. pylori seroprevalence (at least one positive marker) was associated with increasing age, male sex and a diagnosis of peptic ulcer. This association was stronger with duodenal ulcer (multivariate odds ratio (OR), 5.2; 95% confidence interval (CI), 3.5-7.9) than with gastric ulcer (OR, 2.3; 95% CI, 1.2-4.4). Further analyses showed that H. pylori lysate+/cagA- subjects had a moderately increased risk of duodenal (OR, 3.2), but not gastric (OR, 1.1), ulcer. When cagA+ subjects were separately compared with seronegative patients, there was a six-fold increased risk for duodenal ulcer and a three-fold increased risk for gastric ulcer.
  
  
  CONCLUSIONS
  A strong positive association between infection with a cagA+ H. pylori strain and the presence of peptic disease was found. The seroprevalence of anti-cagA antibodies among patients with non-ulcer dyspepsia is so high (41%) to preclude its use as a pre-endoscopic screening test.
authors.affiliation: Epidemiology Unit, CSPO, Florence, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Palli
authors.forename: M
authors.initials: M
authors.lastname: Menegatti
authors.forename: G
authors.initials: G
authors.lastname: Masala
authors.forename: C
authors.initials: C
authors.lastname: Ricci
authors.forename: C
authors.initials: C
authors.lastname: Saieva
authors.forename: J
authors.initials: J
authors.lastname: Holton
authors.forename: L
authors.initials: L
authors.lastname: Gatta
authors.forename: M
authors.initials: M
authors.lastname: Miglioli
authors.forename: D
authors.initials: D
authors.lastname: Vaira
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000907:Antibodies, Bacterial / Q000302:isolation & purification*; D016022:Case-Control Studies; D004381:Duodenal Ulcer / Q000453:epidemiology* / Q000382:microbiology; D005260:Female; D005773:Gastroscopy; D016481:Helicobacter Infections / Q000453:epidemiology*; D016480:Helicobacter pylori / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D010437:Peptic Ulcer / Q000453:epidemiology* / Q000382:microbiology; D016036:Seroepidemiologic Studies
chemical_list: D000907:Antibodies, Bacterial; D007074:Immunoglobulin G