拉米夫定治疗后慢性乙肝患者HBV基因组RT区和S区变异分析  

Variability of Reverse Transcriptase Gene and S Gene in Lamivudine-treated Chronic Hepatitis B Patients

作　　者：钱福初[1] 秦基取[1] 李栋立 王伟洪[1] 戴利成[1] 

机构地区：[1]浙江省湖州市中心医院,湖州313000

出　　处：《病毒学报》2015年第4期433-439,共7页Chinese Journal of Virology

基　　金：湖州市公益性技术应用研究(一般)项目(No.2014GY12)

摘　　要：为了解拉米夫定治疗后发生酪氨酸-蛋氨酸-天冬氨酸-天冬氨酸(Tyrosine(Y)-methionine(M)-aspartic acid(D)-aspartic acid(D),YMDD)基序变异慢性乙肝患者乙肝病毒逆转录基因(Reverse transcriptase,RT)变异特点及对与之相重叠的表面抗原基因区(Surface antigen region,S)变异的影响,为乙肝的诊断和治疗理论提供依据。本研究应用聚合酶链反应(Polymerase chain reaction,PCR)方法对25例发生YMDD变异慢性乙肝患者和30例未进行抗病毒治疗的慢性乙肝患者乙肝病毒(Hepatitis B virus,HBV)基因组RT基因进行扩增,扩增产物进行直接测序分析。结果显示发生YMDD变异患者rt204位点变异类型分布以rtM204I为主(20/25,80%),多伴有rtL80I变异(14/20,70%);rtM204V变异同时伴有rtL180M变异(5/5,100%)。YMDD变异患者RT区变异发生率高于未治疗患者(P<0.05)。YMDD变异患者在5个经典核苷类耐药相关位点(rtL80,rtV173,rtL180,rtM204和rtM250)存在变异。两组患者在其它19个潜在核苷类耐药相关位点存在变异,而YMDD变异患者RT区潜在核苷类耐药相关位点变异频率显著高于未治疗患者(P<0.05),而且还存在对其它(拉米夫定以外)核苷类药物耐药相关位点的变异。发生YMDD变异患者S区变异发生率高于未治疗患者(P<0.05),在YMDD变异患者的S区"a"决定簇中还出现了sM133L和sG145R变异。研究表明拉米夫定治疗后发生YMDD变异患者HBV基因组RT区除发生rtM204I/V变异外还发生了其它耐药相关位点变异,可能导致对其它核苷类的交叉耐药。同时RT区变异影响重叠的S基因区造成HBsAg变异,可能造成对HBsAg检测的影响和免疫逃避的发生。We wished to undertake molecular characterization of the reverse transcriptase（RT）gene and overlapping surface（S）gene in lamivudine-treated patients with chronic infection with the hepatitis B virus（HBV）.Sequencing analyses of the HBV RT/S gene of isolates from 25 chronic hepatitis B（CHB）patients with the YMDD mutation and 30treatment-nave CHB patients were undertaken.In patients with the YMDD mutation,rtM204 Iwas the major type of mutation（20/25,80%）.rtL80 Iwas present in most of the patients with rtM204I（14/20,70%）.rtL180 M coexisted with rtM204V（5/5,100%）.Patients with the YMDD mutation had a significantly higher prevalence of mutation of the RT gene than treatmentnave CHB patients（P〈0.05）.Classical primary resistance and secondary/compensatory mutations were detected at only five sites（rtL80,rtV173,rtL180,rtM204,rtM250）in CHB patients with the YMDD mutation.The frequency of nucleos（t）ide analog resistance（NAr）mutation within the RT gene in patients with the YMDD mutation was significantly higher than that in treatment-nave patients（P〈0.05）.Amino-acid mutations within the RT gene were also associated with other types of NAr in patients with the YMDD mutation.The rate of amino-acid variants within the S gene region was significantly higher in patients with the YMDD mutation than that in treatment-naive patients（P〈0.05）.sM133 Land sG145Rvariants were also present in patients with the YMDD mutation.These observations suggest that CHB patients with the YMDD mutation also have NAr mutations related to other NA drugs,which might lead to cross-resistance in CHB patients.Variants present in the S gene region could cause changes in the antigenicity of HBsAg,which could result in a false-negative diagnosis of HBsAg and immune in escape of the HBV.

关 键 词：乙型肝炎病毒 拉米夫定 逆转录酶 乙肝表面抗原 变异 

分 类 号：R512.62[医药卫生—内科学]