Investigation of the relationship between apolipoprotein E gene polymorphisms and hepatitis B virus infection in northern China.

BACKGROUND: Certain genetic polymorphisms can lead to differences in immunity function, resulting in different clinical outcomes for hepatitis B virus (HBV) patients. The aim of this study was to investigate the association between apolipoprotein E (ApoE) gene polymorphisms and HBV infection status in northern Chinese individuals. METHODS: Genomic DNA was extracted using an improved sodium iodide (NaI) method from the peripheral blood of 270 patients with hepatitis B and 112 healthy controls. Multiplex Amplification Refractory Mutation System (Multi-ARMS) was performed to analyze ApoE gene polymorphisms with three alleles (ɛ2, ɛ3, ɛ4) in patients and controls. A chemiluminescence assay was used to detect serological markers for hepatitis B infection status. RESULTS: An improved PCR system for the detection of ApoE gene polymorphisms was established successfully. The frequency of the ɛ2 allele in patients with HBV infection was higher than that of normal controls (p<0.05). The ɛ2 allele, compared with the ɛ3 and ɛ4 alleles, showed positive correlation with the different HBV infection models [odds ratio (OR)=1.735, 95% confidence interval (CI): 1.509-1.999, p<0.01; OR=1.768, 95% CI: 1.554-2.011, p<0.01]. The OR for the ApoE ɛ2 allele was 1.503 in a multivariate unconditional logistic regression model (OR=1.503, 95% CI: 1.212-1.754, p<0.01). CONCLUSIONS: Our results indicated that the ApoE gene polymorphism was associated with HBV infection, and the ɛ2 allele showed positive correlation with HBV infection in northern China.