乙型肝炎病毒基因型C亚型和核心启动子、前C/核心区基因变异的关系

Relationship between HBV/C subgenotypes and gene mutation of core promoter, precore/core region

目的研究慢性乙型肝炎病毒(HBV)感染者中HBV基因型C亚型(HBV/C)的核心启动子、前C/核心区基因变异情况,分析HBV/C亚型的病毒学特征。方法用酶联免疫法(ELISA)筛选出79例HBV/C,再用聚合酶链反应-限制性酶长度多态性分析方法(PCR-RFLP)进行HBV/C亚型分析;同时针对HBV核心启动子、preC/核心区基因进行半巢式PCR及PCR产物直接测序。结果①79例HBV/C中,33例(41·8%)为HBV/C1亚型,46例(58·2%)为HBV/C2亚型。②HBV/C1亚型仅见于来自中国南方的患者(P<0·0001)。③A1898位点变异仅见于HBV/C1亚型(P=0·056),V1753位点变异在HBV/C1亚型中多见(P<0·05);HBV/C2以T1858(90%)、A1896(40%)位点变异多见(P<0·008)。T1762/A1764位点变异在HBV/C两种亚型中均常见。④肝细胞癌(HCC)患者中,V1753和T1762/A1764变异最常见(P<0·05)。结论HBV/C1和HBV/C2在中国有明显的地区差异;V1753合并T1762/A1764双变异与发展为HCC相关,尤其在HBV/C1患者。

Objective To study the core promoter, precore/core region mutation of HBV/C subgenotypes and to analyze the virological features. Methods A total of 79 sera of HBV/C genotype were chosen by the enzyme-linked immunosobent assay （ELISA）. Then HBV/C strains were subtyped by polymerase chain reactioin and restricion fragment length polymporphism （PCR-RFLP）, and their HBV DNA sequences bearing the core promoter, precore/core region were amplified by hemi-nested PCR, products thereof were directly sequenced. Results （1） Among 79 sera of HBV/C, 33 （41.8%） of subtype HBV/C1 and 46 （58.2%） of subtype HBV/C2 were detected. （2）The HBV/C1 was found only in patients from Southern China. （3） Prevalence of V1753 was higher in HBV/C1 strains （ P 〈 0.04）, A1898 was only found among HBV/C1. HBV/C2 distinguished by frequently found T1858 （90%） and A1896 （40%）. TI762/AI764 was frequent in both subgenotypes. （3） Mutations associated with HCC in the present study were V1753 and TI762/AI764. Conclusions HBV/C1 and HBV/C2 have distinct geographic distribution in China. V1753 in addition to TI762/AI764 double mutation would be associated with HCC development, especially among patients with HBV/C1.