title: Association of the HLA-DRB1 gene locus with gastric adenocarcinoma in Japan.
abstract: OBJECTIVE
  Helicobacter pylori infection is associated with gastric adenocarcinoma, however, the odds ratio is relatively low. The aim of the present study was to investigate host genetic factors that increase the risk of gastric adenocarcinoma among H. pylori-infected individuals.
  
  
  METHODS
  A total of 70 patients with early gastric adenocarcinoma and 121 unrelated healthy controls were examined for H. pylori infection and HLA-DRB1 genotyping. The frequencies of HLA-DRB1 alleles were compared among groups.
  
  
  RESULTS
  The allele frequency of DRB1*04051 was significantly higher in patients with gastric adenocarcinoma (17.9%) than in controls (7.9%) (P(correct) = 0.045). The odds ratio of gastric adenocarcinoma associated with the presence of the HLA-DRB1*04051 allele compared with its absence was 2.55 (95% confidence limits, 1.35-4.83). This genetic risk was not associated with H. pylori infection. There was no significant difference in the HLA-DRB1 allele frequency between H. pylori-positive and H. pylori-negative controls. The frequency of genotypes that possessed the DRB1*04051 allele in gastric adenocarcinoma patients (34.3%) was significantly higher than that in H. pylori-negative controls (11.9%) (p = 0.0089) and H. pylori-positive controls (15.2%) (p = 0.0066).
  
  
  CONCLUSIONS
  These findings suggest that immunogenetic factors for susceptibility to gastric adenocarcinoma are present in the host, the HLA-DRB1*04051 allele is a host genetic risk factor for gastric adenocarcinoma, and that this genetic risk is independent of H. pylori infection.
authors.affiliation: Second Department of Internal Medicine, Fukui Medical University, Matsuoka-cho, Yoshida-gun, Fukui 910-1193, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Ohtani
authors.forename: T
authors.initials: T
authors.lastname: Azuma
authors.forename: S
authors.initials: S
authors.lastname: Yamazaki
authors.forename: A
authors.initials: A
authors.lastname: Yamakawa
authors.forename: Y
authors.initials: Y
authors.lastname: Ito
authors.forename: A
authors.initials: A
authors.lastname: Muramatsu
authors.forename: M
authors.initials: M
authors.lastname: Dojo
authors.forename: Y
authors.initials: Y
authors.lastname: Yamazaki
authors.forename: M
authors.initials: M
authors.lastname: Kuriyama
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics / Q000276:immunology / Q000382:microbiology*; D016022:Case-Control Studies; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D015798:HLA-DR1 Antigen / Q000235:genetics*; D016481:Helicobacter Infections / Q000150:complications / Q000235:genetics*; D016480:Helicobacter pylori / Q000235:genetics* / Q000276:immunology; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D013274:Stomach Neoplasms / Q000235:genetics / Q000276:immunology / Q000382:microbiology*
chemical_list: D015798:HLA-DR1 Antigen