Sensitivity of L-(-)2,3-dideoxythiacytidine resistant hepatitis B virus to other antiviral nucleoside analogues.

L-(-)2',3'-Dideoxythiacytidine (L(-)SddC, Lamivudine) resistant hepatitis B virus (HBV) develops in patients after prolonged treatment. Point mutations detected in the viral genome from these patients have been shown to be responsible for L(-)SddC resistance. Therefore, new drugs active against L(-)SddC resistant HBV are needed. Using a transient transfection system, we studied the sensitivity of L(-)SddC resistant HBV to other anti-HBV nucleoside analogues. It was found that the L526M mutation alone caused greater resistance to penciclovir (PCV) than did the V553I mutation alone. Both mutations also caused the virus to be less sensitive to L(-)SddC and 2'-fluoro-5-methyl-beta-L-arabinofuranosyluracil (L-FMAU), although the degree of resistance was much less than that to PCV. The A546V mutation had no impact on the sensitivity to L(-)SddC, L-FMAU, and PCV. When these single mutations were coupled with the M550V/I mutation, all the double mutants were resistant to those drugs. Although 2',3'-dideoxy-2',3'-didehydro-beta-L(-)-5-fluorocytidine (L(-)Fd4C) was also less active, the IC50 of L(-)Fd4C against the L(-)SddC resistant mutant was at least fifty times lower than that against cell growth in culture. DNA polymerase associated with L(-)SddC resistant virions was also found to be less sensitive than that with wild-type HBV to those L-nucleoside triphosphates. All the L(-)SddC resistant mutants were still sensitive to 9-(2-phosphonylmethoxyethyl)-adenine (PMEA). These results suggest that different mutations in the HBV genome have a different impact on its sensitivity to those compounds, and L(-)SddC resistant HBV may also be resistant to PCV, L-FMAU, and L(-)Fd4C. A nucleoside analogue less toxic than PMEA could be developed against L(-)SddC resistant HBV.     

乙型肝炎病毒前C区及基本核心启动子区变异的临床研究

目的 研究慢性乙型肝炎病毒(HBV)前C区G1896A变异、基本核心启动子(BCP)A 1762T/G1764A变异及二者联合变异在HBeAg阴性和HBeAg阳性慢性乙型肝炎(CHB)患者中的变异特点及与病情进展的关系.方法 将120例HBV DNA阳性CHB患者分为A、B两组,A组为HBeAg阴性CHB患者60例,B组为HBeAg阳性CHB患者60例,用荧光定量PCR检测A、B两组HBV DNA水平,用直接测序法检测A、B两组前C区G1896A及BCP区A1762T/G1764A变异的发生率.根据前C区及BCP区测序结果又分为变异组和无变异组,分析前C区及BCP区变异发生与病情进展的关系.结果 120例HBV DNA阳性CHB患者中A组检出变异株47例,B组检出变异株15例,A组和B组CHB患者中G1896A变异检出率分别为40.0％和10.0％ (x2=14.40,P=0.000);A1762T/G 1764A变异检出率分别为38.3％和15.0％(x2=8.35,P=0.003);联合变异的检出率分别为21.7％和0％(x2=14.58,P=0.000).120例CHB患者中G1896A、A1762/G1764A、联合变异的变异组HBV DNA含量明显高于无变异组HBV DNA含量,P＜0.05,差异有统计学意义.HBeAg阴性CHB患者轻、中、重度不同病情中,G1896A变异、A1762T/G1764A变异及联合变异的变异组与无变异组比较,差异有统计学意义(P＜0.05).结论 (1 )HBV前C区G1896A变异和BCP区A1762T/G 1764A变异是导致HBeAg阴性、HBV DNA持续阳性的主要机制之一.(2) HBV前C区G1896A变异和BCP区A1762T/G 1764A变异可能加重HBeAg阴性CHB患者病情的发展.     

核苷类药与慢性HBV感染者病毒P基因准种及变异特点的关系

目的观察核苷类药治疗不同时间段慢性HBV感染患者血清乙肝病毒聚合酶(HBV P)基因准种变化及变异特点。方法运用焦磷酸测序仪器配套的软件Assay Design SW在目的区域两端保守区域设计PCR引物及测序引物,采用套式PCR方法检测血清中HBV DNA,按照Pyro-Mark ID遗传分析系统用SNP模式进行PCR产物(HBV P基因相关位点)的焦磷酸测序和突变频率检测。108例慢性HBV感染患者中用药史明确者同期测定HBV DNA、HBV标志物、ALT。结果108例患者中,61例发生变异,变异模式以经典突变L180M、M204V/I、A181V/T、N236T突变为主,有少量V173L、S202G、T184G突变;其中40例用药史明确患者中,18例发生变异,发生变异者耐药突变型在样本中所占比例为20%-100%,HBV P基因变异可以在HBV DNA、ALT发生突变前、中、后检出。结论焦磷酸测序可以快速检测HBV P基因变异;变异株突变频率变化可初步反映HBVP基因准种异质性;HBV P基因变异模式、突变频率与核苷类药物敏感性密切相关。     

HBV-前C区基因变异与乙肝病毒复制的相关性

目的 研究乙型肝炎病毒(HBV)前C区G1896A变异与乙肝病毒复制的相关性.方法 选取38例慢性轻度,57例慢性中度,29例慢性重度的乙型肝炎患者为研究对象.采用突变特异PCR技术检测HBV前C基因nt1896位点突变情况,并对血清中HBVDNA进行测序.同时检测乙型肝炎病毒HBeAg/抗-Hbe、HBVDNA定量、肝纤维化指标.结果 (1)抗Hbe阳性者在单纯变异株感染的慢性乙型肝炎患者中所占的比例(84.61%)高于单纯野生株感染者(24.32%).(2)随着变异株感染率的增加,HBVDNA的含量增高.(3)随着变异株感染率增加,肝脏纤维化分期的逐渐加重.结论 前C区G1896A变异与乙肝病毒的复制程度相关.     

Inhibition of hepatitis B virus production by modified 2',3'-dideoxy-thymidine and 2',3'-dideoxy-5-methylcytidine derivatives. In vitro and in vivo studies.

The effect of analogues of both 2',3'-dideoxy-3'-fluorothymidine (FddThd) [2',3'-dideoxy-3'-fluorouridine (FddUrd), 2',3'-dideoxy-3'-fluoro-5-chlorouridine (FddClUrd), 2',3'-dideoxy-3'- fluoro-5-bromouridine (FddBrUrd) and 2',3'-dideoxy-3'-fluoro-5-bromovinyluridine (FddBVUrd)] and 2',3'-dideoxy-3'-fluorocytidine (FddCyt) [2',3'-dideoxy-3'-fluoro-5-fluorocytidine (FddFCyt), 2',3'-dideoxy-3'-fluoro-5-chlorocytidine (FddClCyt), 2',3'-dideoxy-3'-fluoro-5-methylcytidine (FddMeCyt), 2',3'-dideoxy-3'-fluoro-5-ethylcytidine (FddEtCyt), 2',3'-dideoxy-3'-chloro-5-methylcytidine (ClddMeCyt), 2',3'-dideoxy-3'-amino-5-methylcytidine (AmddMeCyt), 2',3'-dideoxy-3'-azido-5- methylcytidine (AzddMeCyt) and arabinosyl-5-methylcytosine (AraMeCyt)] were tested for their potential antiviral activity in vitro using the human hepatoblastoma cell line, Hep G2 2.2.15, which was transfected with a vector containing hepatitis B virus (HBV). It was found that FddThd, FddMeCyt, FddEtCyt, ClddMeCyt, AmddMeCyt and AraMeCyt display cytostatic activity at concentrations (CD50 values) between 0.54 (FddMeCyt) and 3.93 microM (FddEtCyt), while FddUrd, FddClUrd, FddBrUrd, FddBVUrd, FddCyt, FddFCyt, FddClCyt and AzddMeCyt do not affect cell growth at concentrations of up to 25 microM. Among the thymidine analogues tested, FddThd is the most effective antiviral agent: at a concentration of 0.03 microM a more than 90% reduction of HBV DNA synthesis was measured. On the other hand, the antiviral indexes displayed by FddClUrd, FddBrUrd and FddBVUrd are higher than tht of FddThd; FddUrd was completely inactive. The most powerful antiviral agents in the group of cytidine analogues tested in vitro were FddMeCyt (more than 90% reduction of HBVDNA synthesis at 0.10 microM) and ClddMeCyt (0.10 microM); FddClCyt, FddEtCyt, AmddMeCyt and AraMeCyt were of intermediate activity. None of the negligible antiviral activity was determined for FddUrd, FddCyt, FddFCyt and AzddMeCyt. FddThd and FddMeCyt displayed in vivo an antiviral effect in the duck/duck HBV (DHBV) animal system. Administration of 10 or 20 mg/kg (total daily dose) of FddThd and 5 or 10 mg/kg of FddMeCyt (i.m. daily) to ducks infected with DHBV for 12 days blocked virus production. Termination of treatment with FddThd of infected animals led to reappearance of the virus in the serum though at lower levels. The in vitro and the in vivo data suggest that FddThd and FddMeCyt might be promising antiviral agents for the treatment of infection caused by HBV in humans.     

Assessment of the effect of phosphorylated metabolites of anti-human immunodeficiency virus and anti-hepatitis B virus pyrimidine analogs on the behavior of human deoxycytidylate deaminase

Deoxycytidylate deaminase, catalyzing the conversion of dCMP to dUMP, is an important enzyme in the de novo synthesis of thymidine nucleotides. It also may be involved in the action, as well as the metabolism of anticancer agents. Recently, several L- and D-configuration pyrimidine deoxynucleoside analogs were found to be potent antiviral and antitumor agents. Their interaction with dCMP deaminase as a monophosphate or a triphosphate metabolite is not clear. These include D-nucleoside analogs such as beta-D-2',3'-dideoxycytidine (ddC), beta-2'-fluoro-5-methyl-arabinofuranosyluracil (FMAU), 3'-azido-2',3'-dideoxythymidine (AZT), and 2',3'-didehydro-2',3'-dideoxythymidine (D4T) as well as L-nucleoside analogs such as beta-L-dioxolane-cytidine (L-OddC), beta-L-2',3'-dideoxy-3'-thiacytidine, beta-L-2',3'-dideoxy-5'-fluoro-3'-thia-cytidine (L-FSddC), beta-L-2',3'-dideoxy-2',3'-didehydro-5-fluorocytidine, and L-FMAU. None of the L-deoxycytidine analog monophosphates act as substrates or inhibitors. Among these pyrimidine deoxynucleoside analog monophosphates, D-FMAU monophosphate (MP) is the most potent competitive inhibitor, whereas L-FMAUMP has no inhibitory activity. Interestingly, AZTMP and D4TMP also have potent inhibitory activities on dCMP deaminase. Among the dCTP and TTP analogs examined, D- and L-FMAUTP were the most potent inhibitors and had the same extent of inhibitory effect. These results suggest that a chiral specificity for the substrate-binding site may exist, but there is no chiral specificity for the regulator-binding site. This is also supported by the observation that L-OddC and L-FSddC have inhibitory activities as triphosphates but not as monophosphates. None of the D- and L-dCTP analogs activated dCMP deaminase as dCTP. The biological activities of AZT and D4T could be partially attributable to their inhibitory activity against dCMP deaminase by their phosphorylated metabolites, whereas that of ddC and the L-deoxycytidine analogs may not involve dCMP deaminase directly.     

乙型肝炎病毒C基因启动子区及前C区突变与乙型肝炎病情的关系

目的分析乙型肝炎病毒(HBV)C基因启动子(BCP)双突变及前C区nt1896位点突变与乙型肝炎临床表现及e抗原(HBeAg)表型的关系。方法采用巢式聚合酶链反应(PCR)扩增nt1660~1935的HBVDNA片段及PCR产物直接测序的方法检测BCP区及前C区基因的变异情况。结果130例经证实为HBVDNA阳性的急慢性肝炎患者中共有75例BCP区nt1762、nt1764双突变,HBeAg阳性组BCP突变者32例(58.2%),而HBeAg阴性组43例(57.3%)。检出前C区nt1896突变者20例,其中慢性肝炎10例(12.8%)、重型肝炎2例(25.0%)、肝硬化8例(22.2%);nt1896突变者在HBeAg阳性组3例(5.5%),HBeAg阴性组17例(22.7%),两组比较差异有统计学意义。nt1896突变组丙氨酸转氨酶(ALT)及HBV DNA水平较无突变组差异均有统计学意义。结论BCP双突变及前C nt1896均与肝炎的慢性化、重型化及肝硬化的发生密切相关,前者对HBeAg的表达及HBV-DNA水平并无明显影响;后者影响HBeAg的表达,并且增强病毒复制水平。     

反义抑制PCR检测乙肝病毒G1896A变异株方法的研究

目的:研究和评估反义抑制PCR检测乙型肝炎病毒(HBV)基因前C区1896位点变异株的方法。方法:根据HBV DNA前C区1896位点碱基的突变,设计一系列引物,其中之一是针对该HBV DNA1896位点野生型碱基的反义引物,PCR扩增时,通过对1896位点野生型碱基序列的竞争性抑制,而阻滞野生株DNA的扩增,从而仅对HBV DN A1896位变异的碱基序列扩增,特异性检测变异株。为了评估该方法的特异性,使用限制性内切酶方法对检测结果进行对比。结果:该方法检测HBV G1896A变异株具有特异性,而且检测的最低值可达5×104IU/ml。对慢性乙肝病例82份,检出突变型样本21例,阳性率25.61%,与限制性内切酶方法检测比较,经统计学处理,χ2检验评价两者无显著意义。结论:该法在对HBV临床标本1896位点变异株检测中特异和灵敏,是一种有效的检测方法。     

Establishment of drug-resistant HBV small-animal models by hydrodynamic injection

In antiviral therapy of hepatitis B virus (HBV) infection, drug resistance remains a huge obstacle to the long-term effectiveness of nucleoside/tide analogs (NAs). Primary resistance mutation (rtM204V) contributes to lamivudine (LAM)-resistance, and compensatory mutations (rtL180M and rtV173L) restore viral fitness and increase replication efficiency. The evaluation of new anti-viral agents against drug-resistant HBV is limited by the lack of available small-animal models. We established LAM-resistance HBV replication mice models based on clinical LAM-resistant HBV mutants. Double (rtM204V+rtL180M) or triple (rtM204V+rtL180M+rtV173L) lamivudine-resistant mutations were introduced into HBV expression vector, followed by hydrodynamic injection into tail vein of NOD/SCID mice. Viremia was detected on days 5, 9, 13 and 17 and liver HBV DNA was detected on day 17 after injection. The serum and liver HBV DNA levels in LAM-resistant model carrying triple mutations are the highest among the models. Two NAs, LAM and entecavir (ETV), were used to test the availability of the models. LAM and ETV inhibited viral replication on wild-type model. LAM was no longer effective on LAM-resistant models, but ETV retains a strong activity. Therefore, these models can be used to evaluate anti-viral agents against lamivudine-resistance, affording new opportunities to establish other drug-resistant HBV small-animal models.Key words: Drug-resistance, Animal models, Hepatitis B virus, Hydrodynamic injection     

拉米夫定耐药慢性乙型肝炎患者HBV多聚酶区基因突变分析

目的探讨拉米夫定（LAM）耐药慢性乙型肝炎（CHB）患者多聚酶区序列突变特点。方法收集63例接受拉米夫定治疗且耐药的CHB患者的临床资料,采用PCR产物直接测序法检测HBVP基因多聚酶区序列耐药变异。结果 63例诊断为耐药的患者中,51例患者检测到LAM相关的HBV多聚酶区基因突变,其中rtM204V/I变异46例（73.0%）,rtL180M变异25例（39.7%）,rtV173L/M变异5例（7.9%）,rtQ214E变异1例（1.6%）,rtS213T变异2例（2.%）12,rtV207L/M/I变异2例（3.2%）,rtA181T变异3例（4.8%）,rtT184I/S/M变异1例（1.6%）。结论对拉米夫定治疗患者的耐药检测除HBV多聚酶区常见的rtLl80M和rtM204V/I位点变异外,还应考虑其他位点的耐药变异。     

基因芯片技术检测肝细胞癌前C区/BCP区基因突变

目的应用基因芯片技术探讨HBV慢性感染并发肝细胞癌(HCC)前C区/BCP区基因突变的临床意义。方法应用基因芯片杂交技术检测46例HBV慢性感染并发肝细胞癌前C区A1896、A1899及BCP区nt1762、nt1764四位点突变,比较各位点突变的发生率;据乙肝血清学标志熏将研究对象分为HBeAg阳性组、HBeAg阴性组两组,比较前C区/BCP区变异与HBeAg分泌障碍的关系,分析前C区/BCP区基因突变与血清HBVDNA定量的关系。结果①用基因芯片法测定46例患者,阳性率91.3%(42/46),A1896突变率52.4%,A1899突变率19%熏nt1762/nt1764联合突变率66.7%。②HBeAg阴性组与HBeAg阳性组比较,A1896突变率、nt1762nt1764联合突变率及多位点突变率明显为高,P<0.05。前C区/BCP区变异组与非变异组比较,HBVDNA定量无显著性差异。结论应用基因芯片法可一次同时检测乙型肝炎病毒多个突变位点熏HBV持续慢性感染并发的HCC前C区/BCP区变异的发生率较高,该变异与HBeAg分泌障碍有关,但与HBVDNA复制水平并无明显相关性。     

Precore/core promoter mutations and hepatitis B virus genotype in hepatitis B and C dually infected patients treated with interferon-based therapy

We studied the prevalence and distribution of precore/basal core promoter (BCP) mutations and hepatitis B virus (HBV) genotypes in HBV/hepatitis C virus (HCV) dually-infected patients, and evaluated their impact on long-term HBV response of interferon (IFN)-based therapy. The HBV genotypes and sequences of the precore/BCP regions were determined in 180 HBV/HCV dually-infected patients and were compared with 90 age, sex and hepatitis B e antigen-matched chronic hepatitis B controls. Serum HBV DNA and hepatitis B surface antigen (HBsAg) were assessed every 3-6 months after therapy with IFN or pegylated-IFN plus ribavirin in 135 dually-infected patients with active hepatitis C. Dually-infected patients had a higher prevalence of genotype C HBV (P = 0.022) and a lower frequency of G1896A mutation (P = 0.004) as compared with controls. Among dually-infected patients, genotype C was associated with a higher frequency of A1762T/G1764A mutation (P < 0.001), but with lower HBV DNA (P < 0.001) and a lower frequency of A1752T/G (P = 0.008), C1799G (P < 0.001) and G1896A mutation (P < 0.001) than genotype B. Based on Cox proportional hazards model, young age (hazard ratio (HR) = 0.952, P = 0.001), sustained virological response to HCV (HR = 4.638, P = 0.044), C1766T mutation (HR = 5.216, P = 0.003) and A1846T mutation (HR = 2.332, P = 0.031) correlated with HBV DNA reactivation (?2000 IU/ml) after therapy. Age (HR = 1.068, P = 0.020), G1896A mutation (HR = 0.140, P = 0.01) and A1846T mutation (HR = 0.086, P = 0.018) were associated with HBsAg seroclearance independently. In conclusion, specific mutations in the precore/BCP regions could be useful in predicting long-term HBV response in HBV/HCV dually-infected patients treated with IFN-based therapy.     

Changes in different regions of hepatitis B virus gene in hepatitis B 'e' antigen-negative patients with chronic hepatitis B: the effect of long-term lamivudine therapy

BACKGROUND: Lamivudine therapy for chronic hepatitis B has been associated with changes in different regions of the hepatitis B virus nucleotide sequence. AIM: To study changes in the sequences of polymerase and precore/core promoter regions of hepatitis B virus, before and during 5 years of therapy with lamivudine. METHODS: Eighty consecutive samples were taken from 10 chronic hepatitis B 'e' antigen-negative patients. RESULTS: Nine patients carried hepatitis B virus precore mutations during the study. Before therapy, wild type was replaced by A1896 in two (20%) cases. During treatment, A1896 reverted transitory to wild type in five cases (50%) and in one case wild type was replaced by A1896. The continuous detection of precore mutations during therapy was associated with a lower response rate. YMDD mutations were observed in nine cases and both, L180M and M204V/I mutations were simultaneously detected in six cases. About 75% of the patients with M204V mutations were responders and none with M204I or mixed pattern sustained response. CONCLUSION: Hepatitis B 'e' antigen-negative patients exhibit changes in the precore regions both spontaneously and under lamivudine therapy, the transitory reversion to wild type being most frequently witnessed. Patients carrying M204V mutations are more likely to respond to therapy. If, in further studies, these results are confirmed some patients with YMDD mutations could benefit from prolonging the duration of lamivudine therapy.     

Dynamics of hepatitis B virus resistance to entecavir in a nucleoside/nucleotide-naïve patient

The genotypic evolution of HBV quasi-species was analyzed in a nucleoside/nucleotide-na?ve patient who developed resistance to entecavir. The lamivudine resistant quasi-species (rtM204V+/-rtL180M), absent at baseline, were emerged as early as 48 weeks after entecavir administration. Entecavir-resistant quasi-species (rtM204V+/-rtL180M plus S202G) were found after week 112 and gradually became the predominant mutations afterwards. The lamivudine- and entecavir-resistant mutations emerged closely in combination with the rtV207L, rtA222T, rtP237T or rtI163V substitutions. Our results indicated that the lamivudine-resistant mutations were developed first and may serve as a prequisite for subsequent entecavir-resistant mutations in this nucleoside/nucleotide-na?ve patient.     

Random mutagenesis of the human adenosine A2B receptor followed by growth selection in yeast. Identification of constitutively active and gain of function mutations

To gain insight in spontaneous as well as agonist-induced activation of the human adenosine A2B receptor, we applied a random mutagenesis approach in yeast to create a large number of receptor mutants and selected mutants of interest with a robust screening assay based on growth. The amino acid sequence of 14 mutated receptors was determined. All these mutated receptors displayed constitutive activity. In particular, single-point mutations at T42A, V54L, and F84S and a triple-point mutation at N36S, T42A, and T66A resulted in high constitutive activity. In addition, a C-terminally truncated (after Lys269) mutant, Q214L I230N V240M V250M N254Y T257S K269stop, was highly constitutively active. The T42A, V54L, and F84S mutants showed a considerable decrease, 4.9- to 6.9-fold, in the EC50 value of 5'-N-ethylcarboxamidoadenosine (NECA), an adenosine analog. Combined mutation of I242T, K269R, V284A, and H302Q, as well as F84L together with S95G, resulted in an even greater potency of NECA of 10- and 18-fold, respectively. In fact, all constitutively active mutants had an increased potency for NECA. This suggests that the wild-type (wt) human A2B receptor itself is rather silent, which may explain the low affinity of agonists for this receptor. To verify the ability of the mutant receptors to activate mammalian second messenger systems, cAMP experiments were performed in CHO cells stably expressing the wt and T42A receptors. These experiments confirmed the increased sensitivity of T42A for NECA, because the EC50 values of T42A and the wt receptor were 0.15 +/- 0.04 and 1.3 +/- 0.4 microM, respectively.     

Synthesis and antiviral evaluation of some beta-L-2', 3'-dideoxy-5-chloropyrimidine nucleosides and pronucleotides

The synthesis and in vitro anti human immunodeficiency virus (HIV) and anti-hepatitis B virus (HBV) activities of some unnatural beta-L-nucleoside enantiomers related to the anti-HIV compound 2', 3'-dideoxy-3'-fluoro-5-chlorouridine (beta-D-3'Fdd5ClU) are reported. In contrast to beta-D-3'Fdd5ClU, beta-L-3'Fdd5ClU and the other L-congeners were devoid of significant anti-HIV effects, but beta-L-2',3'-dideoxy-5-chlorocytidine (beta-L-dd5ClC) and beta-L-2', 3'-dideoxy-3'-fluoro-cytidine (beta-L-3'FddC) showed a distinct anti-HBV activity. Three mononucleoside phosphotriester derivatives with S-pivaloyl-2-thioethyl (t-BuSATE) groups as biolabile phosphate protective groups were also synthesized. The bis(t-BuSATE) derivative of beta-D-3'Fdd5ClU retained anti-HIV activity in thymidine kinase deficient (TK(-)) CEM cells.     

石家庄地区乙型肝炎病毒基因分型及P区耐药基因突变分析

目的:分析石家庄地区乙型肝炎病毒(HBV)基因型分布以及核苷(酸)类似物耐药基因突变状况。 方法:对2011年1月-2013年12月在石家庄市五医院就诊的遵医嘱口服核苷(酸)类似物6个月以上的354例慢性乙型肝炎患者进行HBV P区基因序列测定。结果:HBV B型为17例(4.8%),C型为337例(95.2%);共检出突变182例,在B型中检测出有10例突变(58.8%),在C型中检测出有172例突变(51.1%),两组间突变率无显著差别;182例HBV P区存在突变的病例中以rtL180M+rtM204I/V/S联合突变最多,占突变比例24.2%;其次是rtM204I/V/S单位点突变,占突变比例20.3%,这两种突变模式的比例达到44.5%;第3位是rtL180M+rtM204I/V/S 再加上其他一个或多个位点的突变,占突变比例12.6%。结论:石家庄地区HBV基因型以C型为主;核苷(酸)类似物耐药基因突变以拉米夫定和替比夫定耐药最常见。