Prevalence of HLA-DQ among Patients with H. Pylori and cytotoxic-associated gene (Cag A)

Background: Helicobacter pylori is an important intestinal bacterium associated with gastritis, peptic ulcer disease, and gastric cancer. Antibodies produced against its cytotoxin-binding gene A (CagA) are protective. The host immunological response to H. pylori antigens may be significantly influenced by human leukocyte antigens. Objective: This study was designed to investigate the relation between HLA-DQ genotypes and H. pylori Methodology: One hundred fifty patients have H. pylori and one hundred healthy. H. pylori infection was determined by urea breath test (UBT). Serum concentrations of anti-Cag A IgG were analyzed by ELISA method and HLA-DQ genotypes were analyzed by SSP-PCR. Results: The study showed that patients aged 25-34 years were the most susceptible age group to H. pylori infection. Furthermore, the current study showed a higher incidence of H. pylori infection among females (63.33%), while 36.66% of males were infected with H. pylori. The current study also showed that approximately 72% (48%) of the total number of H. pylori patients were CagA positive (t = 45.00, p = 0.0001). Furthermore, the current study showed that when comparing H. pylori -positive patients with healthy controls, we detected a significantly higher frequency of the HLA-DQA1*05:01 allele (p = 0.0001). The prevalence of the HLA-DQB1*05:02 allele was also found to be not statistically significant in H. pylori patients compared to healthy individuals (P = 0.895). Conclusion: The study showed no significant correlation between the HLA-DQB1*0502 genotype and H. pylori infection; however, HLA-DQA1*0501 may make patients more susceptible to superficial gastritis.