The Role of HLA Class II Gene DQB1 in the Development of Duodenal Ulcer in Helicobacter pylori Infected Patients

Background/Aims: Helicobacter pylori (H. pylori) infection is associated with gastroduodenal ulcer and gastric cancer only in a small proportion of infected subjects. Both virulence factors of H. pylori strains and host immune responses have been suggested to play an important role in the development of such lesions. HLA has been considered as an important host factor in many diseases. The aim of this study was to examine the HLA-DQ loci among duodenal ulcer patients with H. pylori infection as potential host genetic factors related to the development of duodenal ulcer. Methods: Thirty-two duodenal ulcer patients and 74 controls who had endoscopic chronic gastritis were studied. HLA-DQA1 and HLA-DQB1 genotypes were determined by polymerase chain reaction using sequence specific oligonucleotide probes (PCR-SSOP) with peripheral bloods obtained from the patients and controls. Results: HLA-DQA1 distribution pattern of the patients showed no significant difference from that of the controls. However, the frequency of HLA DQB1* 04 was quite lower in the patients than in the controls (p=0.02). Conclusions: The HLA-DQA1 does not seem to contribute to the diseasesusceptibility, whereas HLA DQB1* 04may contribute to the protection from duodenal ulcer in H. pylori infected subjects.