title: In the European population HLA-class II genes are not associated with Helicobacter pylori infection.
abstract: OBJECTIVE
  Genetic variability influences susceptibility to several diseases and depends on the specific ethnic background of individuals. HLA-class II genes have repeatedly been investigated as candidate genes for predisposition to Helicobacter pylori infection. Certain HLA-DQA1 alleles have been reported to be associated with gastric and duodenal ulcer disease in infected patients in the Japanese population. But conflicting results were reported on European and Japanese populations.
  
  
  METHODS
  HLA-DRB1 typing of 382 German individuals with well-defined H. pylori status and different clinical course of the disease was performed by polymerase chain reaction and allele-specific oligonucleotide hybridization.
  
  
  RESULTS
  No association with the infection status itself was observed in the German cohort. Similar results have been found in other European populations. In contrast, re-analysis of published data in a Japanese cohort revealed a highly significant association of DRB1*1501 with uninfected controls (P = 0.00035). In the German population, the carrier frequency of DRB1*15 was higher in H. pylori-positive individuals with gastric or duodenal ulcer but without statistical significance (gastric ulcer: odds ratio, 2.13; chi2 = 3.77; P = 0.05; Bonferroni correction, Pc = not significant; and duodenal ulcer: odds ratio, 2.15; chi2 = 3.4; P = 0.06; Pc = not significant). In infected individuals, autoantibodies to gastric mucosa were investigated, but no statistical significant difference in carrier frequencies of HLA-DRB1 alleles was evident.
  
  
  CONCLUSIONS
  The DRB1*1501-DQA1*01021-DQB1*0602 haplotype seems to provide protection from H. pylori infection in the Japanese population, whereas genetic variability in HLA-class II genes has only a minor impact on H. pylori infection and its clinical course in the European population.
authors.affiliation: Department of Molecular Human Genetics, Ruhr-University, Bochum, Germany. Erdmute.M.Kunstmann@ruhr-uni-bochum.de
authors.forename: Erdmute
authors.initials: E
authors.lastname: Kunstmann
authors.forename: Cornelia
authors.initials: C
authors.lastname: Hardt
authors.forename: Hartmut
authors.initials: H
authors.lastname: Treitz
authors.forename: Sebastian
authors.initials: S
authors.lastname: Suerbaum
authors.forename: Gerhard
authors.initials: G
authors.lastname: Faller
authors.forename: Ulrich
authors.initials: U
authors.lastname: Peitz
authors.forename: Wolff
authors.initials: W
authors.lastname: Schmiegel
authors.forename: Jörg T
authors.initials: JT
authors.lastname: Epplen
mesh_terms: D005060:Europe; D005802:Genes, MHC Class II; D005858:Germany; D006684:HLA-DR Antigens / Q000235:genetics*; D059811:HLA-DRB1 Chains; D016481:Helicobacter Infections / Q000208:ethnology / Q000235:genetics* / Q000276:immunology; D016480:Helicobacter pylori; D006801:Humans; D044465:White People / Q000235:genetics*
chemical_list: D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains