阿德福韦酯耐药慢性乙型肝炎患者HBsAg变异分析

HBs Ag mutations in patients with chronic hepatitis B undergoing adefovir dipivoxil resistance

目的探讨阿德福韦酯耐药慢性乙型肝炎患者相关S抗原变异、疫苗逃逸相关变异以及部分已知特异性T细胞表位变异情况。方法收集2007年12月至2011年9月于首都医科大学附属北京地坛医院收治的阿德福韦酯治疗失败的慢性乙型肝炎患者70例,并随机选择ADV治疗非耐药患者70例作为对照。采用PCR产物直接测序法获得患者HBV反转录酶区与S抗原序列。应用PCR产物直接测序法与焦磷酸测序法明确阿德福韦酯耐药情况。比较阿德福韦酯耐药患者与无阿德福韦酯耐药患者耐药相关S抗原变异、疫苗逃逸相关变异以及HBV特异性T细胞表位变异情况。结果 ADV耐药组与对照组患者人口学等指标差异无统计学意义。本组患者中42例rt A181T耐药变异关联的HBs Ag变异均为s W172*。在rt A181T/s W172*变异患者体内,该变异株在病毒准种中所占平均比率为(42.6±22.1)%(12.2%~100%)。与非ADV耐药组患者相比,ADV耐药组患者发生HBs Ag疫苗逃逸变异(χ2=12.8736、P=0.0003)以及T细胞抗原表位变异(χ2=4.8344、P=0.0279)几率显著升高。结论我国ADV耐药患者rt A181T变异关联的HBs Ag变异主要为s W172*变异,HBs Ag抗原疫苗逃逸变异以及T细胞抗原表位变异与ADV耐药相互影响,相关机制尚待进一步研究。

Objective To investigate adefovir dipivoxil（ADV） resistant mutation related HBs Ag mutation, vaccine escape mutation and T cell epitope mutations in Chinese patients with chronic hepatitis B（CHB） who underwent adefovir resistance. Methods Seventy CHB patients who underwent ADV resistance from December 2007 to September 2011 in Beijing Ditan Hospital, Capital Medical Unversity were enrolled. While 70 ADV treated patients without ADV resistance were randomly selected as control group. HBV Rt/S ORF were sequenced with PCR product Sanger sequencing and pyrosequencing. ADV resistant mutation related HBs Ag mutation, vaccine escape mutation and T cell epitope mutations were compared between ADV treated CHB patients with and without ADV resistance. Results Total of 70 ADV resistant patients with CHB were enrolled, while 70 ADV treated CHB patients without ADV resistance were set as control. Baseline characteristics were comparable between the two groups. All 42 rt A181 T mutations were related to s W172＊mutations. Mean ratio of rt A181 T/s W172＊ mutations in quasispecies was（42.6 ± 22.1）%（12.2%-100%）. More patients in resistance group showed vaccine escape mutation（χ2 = 12.8736, P = 0.0003） and T cell epitope mutations（χ2 = 4.8344, P = 0.0279） than control group. Conclusions In Chinese patients with CHB, rt A181 T is mainly related to s W172＊ mutations. ADV resistance is related to vaccine escape mutation and T cell epitope mutations. Further studies should focus on the possible mechanism.