AASLD 2013:调查HBV rtA181T突变在大量中国慢性HBV患者

StephenW

TITLE: Investigation of HBV rtA181T mutation in a large number of Chinese patients with chronic HBV infection

AUTHORS (FIRST NAME, LAST NAME): Xiaodong Li1, Yan Liu1, Liming Liu1, Pan Zhao1, Jiuzeng Dai1, Zengtao Yao1, Shaojie Xin1, Dongping Xu1
Institutional Author(s):
INSTITUTIONS (ALL): 1. Institute of Infectious Diseases and Liver Failure Research Center, Beijing 302 Hospital, Beijing, China.
ABSTRACT BODY: Aim: The study aimed to investigate HBV rtA181T mutation profile in clinical practice and its clinical implications.
Methods: Serum samples from 18,419 patients collected from July 2007 to June 2012 in Beijing 302 Hospital were investigated. Around 92% patients experienced nucleos(t)ide analogs. The rtA181T mutation and HBV genotype were determined by direct sequence analysis. Viral replication capacity, drug susceptibility and HBsAg secretion were determined in HepG2 cells that had been transfected with replication-competent HBV vectors containing reverse-transcriptase/S genes.
Results: rtA181T was detected from 750 patients. The incidence escalated in the past five years (1.97%, 2.47%, 3.84%, 5.21%, and 6.35%); rtA181T emerged either alone or with other drug-resistant mutations (37.3% alone, 48.6% with adefovir-resistant mutation rtA181V/N236T, 12.1% with lamivudine-resistant mutation rtM204V/rtM204I, and 2.0% with entecavir- or multidrug-resistant mutations, respectively). In patients harboring rtA181T, 96.7% experienced adefovir and/or lamivudine, including 19.5% experienced single adefovir, 12.0% experienced single lamivudine, 49.4% experienced both adefovir and lamivudine, and 15.8% experienced adefovir/lamivudine plus telbivudine/entecavir). Only four patients with rtA181T were antivirals-naive. HBV genotype C/B were 93.0%/7.0% for rtA181T positive patients, and 84.6%/15.4% for rtA181T negative patients (P <0.01), suggesting there was a positive link between rtA181T with genotype C HBV. Most but not all rtA181T led to sW172* (stop codon) mutation on overlapping S-gene and coexistence of rtA181T/sW172* with wild-type sequence was frequently detected (22.0% presented as sW172* alone, 69.9% presented as sW172* concomitant with the wild-type, 5.7% presented as sW172* with sW172/L or sW172S, etc). Phenotypic analysis of representative rtA181T/sW172* strains showed that the 50% effective concentration (EC50) values of adefovir for the mutants were 1.8-fold to 2.9-fold higher than that of wild-type strain. By contrast, the EC50 of adefovir for rtA181V or rtN236T mutants was at least 3.5-fold higher than that of wild-type strain. A defect in HBsAg secretion and a decreased replication capacity of rtA181T (sW172*) strain were observed in comparison with wild-type strain in vitro; while no significant difference in average serum HBsAg and HBV DNA levels was observed between patients with and without rtA181T/sW172*.
Conclusions: The emergence of HBV rtA181T mutation is closely associated with adefovir and lamivudine exposure, but it may not directly cause adefovir resistance. The clinical significance of rtA181T should be properly interpreted.

StephenW

目的：研究旨在探讨HBV rtA181T突变在临床实践中的档案及其临床意义。
方法： 18,419收集了从2007年7月至2012年6月北京302医院的患者的血清样本进行了调查。大约92 ％的患者经历了核苷（酸）类似物。 rtA181T突变与HBV基因型的测定采用直接序列分析。已复制能力的HBV逆转录/ S基因载体转染的HepG2细胞中病毒的复制能力，药敏测定HBsAg的分泌。
的结果：使用， rtA181T检测从750名患者。发病率在过去的五年中升级（ 1.97％ ，2.47 ％ ，3.84 ％ ， 5.21 ％和6.35％ ） ; rtA181T出现单独或与其他药物的耐药性突变（ 37.3％ ，仅48.6 ％，阿德福韦耐药突变的rtA181V / N236T ， 12.1％拉米夫定耐药突变rtM204V/rtM204I ，与恩替卡韦或多重耐药性的突变和2.0 ％ ，分别） 。 rtA181T ，经验丰富的阿德福韦96.7 ％和/或拉米夫定，包括经验丰富的单阿德福韦19.5％ ， 12.0％，经验丰富的单拉米夫定窝藏在患者中，49.4 ％经历阿德福韦酯和拉米夫定，和15.8％，经验丰富的阿德福韦/拉米夫定加替比夫定/恩替卡韦） 。 rtA181T仅有4例患者抗病毒药物天真。 HBV基因型C / B分别为93.0 ％ / 7.0 ％ rtA181T阳性的患者中， 84.6 ％ / 15.4 ％ rtA181T阴性患者（P <0.01 ） ，提示有一个rtA181T HBV C基因型之间的积极联系。大部分但不是全部rtA181T SW172 * （终止密码子）突变导致经常被发现与野生型序列（ 22.0％ SW172 *单独的S-基因和共存rtA181T/sW172 *重叠， 69.9％表现为SW172 *伴随与野生型，5.7％ SW172 SW172 / L或sW172S ，等） * 。代表rtA181T/sW172 *菌株的表型分析表明，阿德福韦的突变体的50％有效浓度（ EC50 ）值分别为1.8倍至2.9倍，高于野生型菌株。与此相反，阿德福韦酯的rtA181V或rtN236T突变体的EC50是高于野生型菌株的至少3.5倍。乙肝表面抗原分泌的缺陷和复制能力下降rtA181T （ SW172 * ）株与野生型菌株在体外相比，平均血清HBsAg和HBV DNA水平，而没有显着的差异，观察患者之间并没有rtA181T / SW172 * 。
结论：阿德福韦酯和拉米夫定曝光rtA181T突变HBV的出现密切相关，但它可能不会直接导致阿德福韦耐药。 rtA181T的临床意义，应适当的解释。