Human Leukocyte Antigen Class I Association with Occult Hepatitis B Virus Infection in Shaanxi Han Group: Analysis at the Haplotype Level.

BACKGROUND Previous researches have confirmed that human leucocyte antigen (HLA) class I genes and haplotypes were correlation with hepatitis B virus (HBV) infection. Occult HBV infection (OBI), a special type of chronic HBV infection, is defined as HBV surface antigen (HBsAg) negative patients with or without serologic markers by the means of HBV DNA detection in human plasma or in liver tissue by diagnostic test. So far, the associations of HLA I haplotypes with OBI have not been reported previously in China. METHODS A case-control study between 107 OBI subjects and 280 healthy controls from blood donors in Blood Center of the Shaanxi Province was conducted in present association analysis. The HLA-A, -B, -C loci of case-control subjects were detected and genotyped by polymerase chain reaction-sequence based typing (PCR-SBT). And the HLA-A, -B, -C haplotypic frequencies were calculated by maximum likelihood method. RESULTS The HLA-A*33:03-C*07:01G (Pc=0.039, OR=8.996, 95%CI=1.825-44.338), B*44:03-C*07:01G (Pc=0.0069, OR=12.000, 95%CI=2.507-57.436), A*33:03-B*44:03-C*07:01G (Pc=0.04, OR=7.094, 95%CI=1.387-36.288) haplotypes showed significant positive associated with OBI. Independent effects demonstrated that HLA-B*44:03 and HLA-C*07:01G gave the main contribution to risk, whereas HLA-A*33:03 was associated only by linkage disequilibrium (LD). CONCLUSIONS This study for the first time demonstrated that HLA I haplotypes were associated with OBI in Shaanxi Han population. The present results suggest that HLA-B*44:03-C*07:01G might be a potential risk factor for OBI.