HLA-DQB1 locus and the development of atrophic gastritis with Helicobacter pylori infection.

Helicobacter pylori is known to be involved in digestive diseases such as peptic ulcer, atrophic gastritis, and gastric cancer. It is supposed that the incidence of these digestive diseases associated with H. pylori is influenced by the strain diversity of H. pylori, factors involving the host or environment, and the duration of infection. In this study, we directed our attention to HLA, a host factor, and investigated the relation between HLA-DQB1 genotype of H. pylori-infected patients and the development of atrophic gastritis. HLA-DQB1 genotyping was performed by the polymerase chain reaction-restriction fragment length polymorphism method on 122 H. pylori-infected patients with atrophic gastritis and 28 uninfected Japanese controls. Infected patients with developed atrophic gastritis were classified as the open type and those with undeveloped atrophic gastritis as the closed type. To estimate the grade of atrophic gastritis reliably, histological and serological evaluations were also undertaken. The allele frequency of DQB1*0401 was significantly higher in the open-type group compared to either the closed-type or the uninfected group. These results suggest that immunogenic factors play an important role in the development of atrophic gastritis in H. pylori-infected patients, and that DQB1*0401 is a useful marker for determining susceptibility to this disease.