Association Of Polymorphisms Of HLA-DQA1 And DQB1 Allele With Chronic Hepatitis B Virus Infection, Liver Cirrhosis And Hepatocellular Carcinoma

[Objective] To investigate whether HLA class II DQA1 and DQB1 gene polymorphisms are associated with development of chronic hepatitis B virus (HBV) infection in Shandong province and provide clues to seeking for the susceptible and protective genes for chronic HBV infection, HBV-related liver cirrhosis (LC), and hepatocellular carcinoma (HCC).[Methods] (1) To collect peripheral blood samples: 168 chronic HBV infection patients (including 48 chronic hepatitis B, 42 LC and 78 HCC patients) and 100 controls who had recovered from HBV infection. All patients and controls are Han Chinese from Shandong province. (2) Lymphocytes were isolated from peripheral blood with lymphocytes separation medium. Genomic DNA was isolated from lymphocytes by phenol-chloroform extractions. (3) HLA-DQA1 and DQB1 alleles typing were performed by using polymerase chain reaction amplification with sequence-specific primers (PCR-SSP) in all the patients and controls. The phenotype frequencies were compared between groups divided according to clinical parameters. [Results] (1) We first compared the phenotype frequencies of HLA-DQA1 and DQB1 alleles between chronic HBV infection patients and controls. In chronic HBV infection patients, the phenotype frequency of HLA-DQA1*0102 was significantly decreased(25.6% vs 47.0%, OR = 0.39, P=0.0003 ), while the frequency of DQB1*0201 was significantly increased(37.5% vs 17.0%, OR = 2.93,P=0.0004) compared with controls. Both of the differences were significant even after Bonferroni correction(P_c=0.003, P_c=0.008 ). In addition, the frequencies of DQA1*0601 and DQB1*0601 were significantly increased compared with controls (4.2% vs 0.0%, OR=0.96, P=0.039; 26.8% vs 15.0%, OR=2.07, P=0.025). But neither of the differences was significant after Bonferroni correction (P_c>0.05). There were no significant differences in other DQA1 and DQB1 alleles between chronic HBV infection patients and controls (P>0.05).(2) Secondly, we compared the phenotype frequencies of HLA-DQAl and DQB1 alleles between chronic HBV infection patients with and without LC. The phenotype frequency of DQA1*0104 was significantly decreased in chronic HBV infection patients with LC compared to those without LC (6.4% vs 28.4%, OR=0.17, P=0.0001). This difference is significant even after Bonferroni correction (P_c= 0.001, OR = 0.17). Conversely, in chronic HBV infection patients with LC, the frequency of DQAl*0201 was significantly increased compared with those without LC (27.7% vs 12.2%, P = 0.014, OR = 2.76). However, this association did not achieve statistical significance when Bonferroni correction was applied (P_c>0.05). No other HLA-DQAl and DQB1 allele associations were found (P>0.05).(3) Finally, we compared the phenotype frequencies of HLA-DQAl and DQB1 alleles between chronic HBV infection patients with and without HCC. Our data showed that there was no significant association between HLA-DQA1 and DQB1 gene polymorphisms and the presence of HCC(P>0.05).[Conclusion] HLA-DQA1*0102 and DQA1*0104 are associated with protection from chronic HBV infection and development of LC, respectively, whereas DQB1*0201 confers susceptible effect on chronic HBV infection. There was no significant association between HLA-DQA1 and DQB1 gene polymorphisms and development of HCC in chronic HBV infection patients.