HLA-DRB1 and primary biliary cholangitis: The results indicate that the frequency of the HLA-DRB1*13 allele in PBC patients is significantly higher than in controls, but this relationship was not observed in individuals who carried the HLA-DRB1*13 allele between the PBC group and control group (OR = 0.668, 95%CI: 0.428–1.043; I2 = 59.0%, P = 0.045).