Association of selected human leukocyte antigen alleles (HLA-DQA1*0102, HLA-DQA1*0103 and HLA- DQB1*0301) with Helicobacter pylori infection among dyspeptic patients

Helicobacter pylori has been identified as a group I carcinogenic bacteria that infect the gastric mucosa leading to gastritis, peptic ulcer disease, lymphoma and gastric cancer. Pathogenesis of H. pylori depends on the virulence of the strain, host immune response and modulating factors like smoking and diet.
This study aimed to assess the association of selected HLA (Human Leukocyte Antigen) alleles; HLA-DQA1*0102, HLA-DQA1*0103 and HLA-DQB1*0301, with the presence of H. pylori infection and disease severity among dyspeptic patients.
Gastric tissue samples from 100 dyspeptic patients, who underwent upper gastrointestinal endoscopy at a tertiary care hospital, were collected. Presence of HLA alleles was confirmed using Polymerase Chain Reaction (PCR). H. pylori infection was determined using PCR and Histology. The histological interpretation was done according to the ‘Sydney classification’. Statistical analysis was done with the Statistical Package of Social Sciences (SPSS) (version 22; SPSS, Inc., Chicago, Illinois, USA).
Respective percentages of HLA-DQA1*0102, HLA-DQA1*0103 and HLA-DQB1*0301 were 39%, 31% and 20%. Of the 25 samples positive for H. pylori infection respectively 56% (14/25), 36% (9/25) and 12% (3/25) were positive for HLA-DQA1*0102, HLA-DQA1*0103 and HLA-DQB1*0301 alleles. Considering the association with H. pylori infection, only HLA-DQA1*0102 showed significant association (p=0.044). No significant association was found between the HLA alleles and the histological severity among the H. pylori infected patients.
In conclusion, HLA-DQA1*0102 allele has a significant association with H. pylori infection while HLA-DQA1*0103 and HLA-DQB1*0301 shows no significant association in a Sri Lankan dyspeptic patient population.