乙型肝炎病毒X基因变异和慢性乙型肝炎患者临床与组织病理学指标的相关性

 目的 探讨慢性乙型肝炎患者肝组织内乙型肝炎病毒（HBV）X基因部分区段的变异与HBV相关各临床与组织病理学指标的关系。方法 以83例慢性乙型肝炎肝穿刺活检标本作为研究对象，20例HBV相关性肝细胞癌作为对照；HBV X基因变异的研究采用PCR扩增和直接双向测序。免疫组化二步法显示肝组织内四种病毒蛋白的表达；荧光实时定量PCR检测肝组织内HBV DNA含量。结果 HBV X基因nt1583～1793区段错义突变主要出现在对应的X蛋白aa87（nt1632、1633）、88（nt1635、1636）、116（nt1719）、118（nt1726、1727）、119（nt1730）、127（nt1752）、130（nt1762）和131（nt1764）位氨基酸。nt1725～1730（aa118/119）突变与肝组织内HBcAg显著低表达（P=0.006），和HBV DNA低拷贝数（P=0.004）明显相关，尤以ACTGAC（TD）型突变最为明显；相反，nt1762/1764（aa130/131）位点突变则伴肝组织内HBcAg显著高表达（P=0.005）和高水平的HBV DNA含量（P=0.006）。同时，肝癌组中nt1725～1730 野生型所占比率明显高于慢性肝炎（P<0.05），而nt1762/1764 突变型所占比率肝癌组与肝炎组相比显著增高（P<0.01）。结论 肝组织内，在nt1725～1730突变能显著降低HBcAg 的表达和HBV DNA水平，nt1762/1764突变则相反。肝组织内HBV的高负载可能与肝细胞癌的发生有关

Hepatitis B virus X mutations affect clinicopathological or histopathological characteristics in patients with chronic hepatitis B virus infection

Objective To study the relationship between the mutations of hepatitis B virus X gene and the HBV-related clinicopathological or histopathological characteristics in patients with chronic hepatitis B. Methods Eighty-three cases of chronic hepatitis B with liver biopsy were enrolled, and 20 HBV-related hepatocellular carcinoma cases were taken as a control. Sequence analysis was performed by polymerase chain reaction (PCR) and the direct sequencing method. Two-step immunohistochemical staining showed the expression of four HBV antigens in situ. HBV DNA level in liver was determined by fluorescence quantitative real-time PCR. Results Missense mutations from nt1583 to nt1793 of HBV X gene were detected in position aa87 (nt1632,1633),88 (nt1635,1636),116 (nt1719),118 (nt1726,1727),119 (nt1730),127 (nt1752),130 (nt1762) and 131 (nt1764). Mutation at nt1725-1730 correlated significantly with the decreased expression of HBcAg in situ (P=0.006), as well as lower HBV DNA levels in liver (P=0.004). Especially CTGAC mutation had the strongest decrease of the viral load (P=0.007). On the contrary, nt1762/1764 mutation correlated with the increased HBcAg (P=0.005) and higher HBV DNA levels (P=0.006). The mutants with the wild-type of nt1725-1730 or nt1762/1764 mutation were more prevalent in patients with hepatocellular carcinoma than in patients with chronic hepatitis B. Conclusions Mutations at nt1725-1730 and nt1762/1764 are associated with in situ expression of HBcAg and viral load. Higher HBV DNA levels in liver is possibly associated with hepatocarcinogenesis.