人核苷转运蛋白1（hCNT1）及多药耐药蛋白4(MPP4)基因多态性对慢性乙型肝炎核苷类似物抗病毒治疗应答的影响

Response of antivirus treatment on chronic hepatitis B is affected by drug, virus and host.Among them, intracellular transport of drug mediated by host is an important link of drug's action, and transport efficiency is influenced by genetic polymorphism of the host. But studies of this field are few..This study select people concentration nucleoside transporters 1 (hCNT1 / SLC28A1) and multi-drug resistance associated protein 4(MRP4/ABCC4) as candidate gene according to results of cell membrane transport protein gene polymorphism in AIDS studies. Study will be done from two aspects including transportation of drugs to intracellular and transpiration of drugs to extracellular. Patients who received initial treatment with entacavir or telbivudine for at last 24 week with poor or complete response were enrolled. The Multiplex SNPshot single base extension will be done to analysis polymorphism of candidate genes and explore relevance between response and gene polymorphism..The purpose of this study is to analysis the influence of hCNT1 and MRP4 gene polymorphism on treatment response and explore action and mechanism of genetic diversity of host on antivirus treatment. The results will be foundation for large scale host gene polymorphism research in the future and provide theoretical basis and technical means for individual antivirus treatment and curative effect prediction.

慢性乙型肝炎抗病毒治疗应答与否受药物、病毒和宿主的影响。其中，由宿主介导的药物细胞内转运是药物发挥作用的重要环节，而转运效率受宿主基因多态性的影响，但该领域的相关研究较少。.本课题拟借鉴艾滋病中细胞膜转运蛋白基因多态性的研究结果，从药物向细胞内转运及向细胞外排出两个方面入手，选择人核苷转运蛋白1 （ hCNT1/ SLC28A1 ）及多药耐药蛋白4（MRP4/ABCC4）作为候选基因，纳入初始使用恩替卡韦或替比夫定治疗分别表现为应答不佳及完全应答的慢乙肝患者作为研究对象，采用Multiplex SNPshot单碱基延伸技术进行候选基因的多态性分析，探索应答与基因多态性的相关性。.本研究通过分析hCNT1及MRP4基因多态性对慢性乙肝抗病毒治疗应答的影响，探讨宿主遗传多样性在抗病毒治疗中的作用及机制，为今后大规模的宿主基因多态性研究打下基础，进一步为个体化抗病毒治疗提供理论依据及技术手段。

本课题共纳入498例我院就诊的慢性乙型肝炎初治患者，其中ETV患者324例，LdT患者174例，给予恩替卡韦0.5mg qd或替比夫定600mg qd，每三个月随访，至少随访1年。在治疗0周、12周、24周及48周采集临床资料及血样标本。根据拟定的标准将患者分为原发部分应答（PPR）及完全病毒应答（CVR）两组，排除病毒学耐药位点突变的因素，应用Multiplex SNaPshot单碱基延伸技术对两组患者的SLC28A1基因，ABCC4基因，ABCC5基因共计18个SNP位点（SLC28A1 rs2242046，rs2242047，rs2290272，rs8187758，rs59738243；ABCC4 rs3770，rs1059751，rs2274407，rs3742106，rs3751333，rs3765534，rs4148551，rs4148553，rs11568658，rs11568681；ABCC5 rs3749445，rs3805114，rs562）进行测序。.结果显示：1、多因素分析发现患者基线的性别、年龄、E抗原状态、HBV基因型等对ETV和LdT抗病毒应答无显著的影响，而基线ALT水平、基线HBV DNA水平可影响抗病毒疗效，尤其对LdT的治疗；2、ABCC4的rs3751333等位基因型及等位基因分布频率对ETV抗病毒治疗的应答有影响（P=0.005；p=0.004），rs3751333 G/G等位基因型可能会提高抗病毒治疗的应答率；3、LdT组单倍型分析发现ABCC4的单倍型A/A/C/C/G/C/C/C/A/G组合及SLC28A1的单倍型G/T/A/A/G组合有统计学意义（P=0.019；P=0.0001）。说明这两种基因的单倍体组合可能影响LdT的抗病毒应答；4、ETV组单倍型分析提示ABCC4，SLC28A1和ABCC5相关基因位点的单倍型组合均无统计学意义(P>0.05)；5、其余SNP位点无论是等位基因型还是等位基因分布频率，两组间差异无统计学意义，尚不能说明其对核苷类似物乙肝抗病毒应答有影响。.综上所述，ABCC4的rs3751333 GG等位基因型提高了ETV抗病毒治疗的应答，ABCC4的单倍型A/A/C/C/G/C/C/C/A/G组合以及SLC28A1的G/T/A/A/G组合，可能影响LdT的抗病毒应答。