Interaction between gene A-positive Helicobacter pylori and human leukocyte antigen II alleles increase the risk of Graves disease in Chinese Han population: An association study

ObjectiveThe current study explored the correlation of Helicobacter pylori and the polymorphisms of human leukocyte antigen II (HLA-II) alleles with Graves disease (GD).MethodsA total of 216 patients with GD were recruited. 102 healthy volunteers constituted the control group. Levels of H. pylori immunoglobulin G (IgG) antibodies and H. pylori cytotoxin-associated gene A (CagA) IgG antibodies were detected using enzyme-linked immunosorbent assays. Molecular typing of the HLA-II alleles was conducted using polymerase chain reaction with sequence specific primers.ResultsH. pylori, particularly CagA-positive strains, HLA-DQA1*0201, and HLA-DQA1*0501 were associated with GD (P = 0.015, OR = 1.811; P = 0.000, OR = 3.085; P = 0.000, OR = 0.315; and P = 0.004, OR = 2.844, respectively). Patients with CagA-positive H. pylori and negative HLA-DQA1*0201 or positive HLA-DQA1*0501 were more likely exposed to GD compared with those with only one of these indices.ConclusionCagA-positive H. pylori, negative HLA-DQA1*0201, or positive HLA-DQA1*0501 may increase the risk of GD.