基因芯片技术检测在乙型肝炎病毒基因突变分析中的应用

目的:探讨DNA芯片在乙型肝炎病毒基因突变分析中的应用及临床意义。方法:用基因多态性检测芯片检测HBV DNA阳性慢性乙型肝炎(CHB)患者血清前C区1896/1814位点、基本核心启动子区(BCP区)1762/1764位点及P区528/552位点突变情况,并与血清转氨酶、血清HBV DNA复制程度、血清e系统进行对比分析。结果:未接受抗病毒药物拉米夫定治疗的12例HBsAg( )、HBeAg( )、HBeAb(-)的患者血清中未检测到病毒变异,其他患者中未检测到P区基因变异;30例接受拉米夫定治疗48-96周后的HBV DNA阳性患者中,有19例患者检测到YMDD变异,并出现血清转氨酶升高,HBV DNA复制再度活跃。结论:前C区、BCP区突变较多的出现在HBeAb( )的患者中并与HBeAg的阴性表型相关,BCP区突变与HBeAg/HBeAb血清学转换密切相关,而P区528/552位点突变更多的出现在接受拉米夫定治疗后的患者中,与拉米夫定耐药相关且加重肝损害;基因芯片技术检测乙型肝炎病毒多位点变异对临床判断病情具有一定的参考意义。     

慢性乙型肝炎治疗过程中病毒基因变异及临床意义的研究

目的研究干扰素和拉米夫定治疗慢性乙型肝炎HBV前C区A83点突变及YMDD变异的发生情况,并探讨联合治疗对慢性HBV基因变异的影响.方法90例慢性乙型肝炎病人进行随机化分组,30例肌肉注射干扰素,30例常规口服拉米夫定100 mg/d,30例给予拉米夫定和干扰素联合治疗.治疗前检测血清丙氨酸转移酶水平,HBV DNA滴度(定量)水平,前C区A83点突变和YMDD变异,治疗后第1、3、6、9个月分别进行肝功能、HBV DNA定量检测,应用错配聚合酶链反应及限制性片断长度多态性(mPCR-RFLP)检测HBV基因变异的发生情况,对干扰素治疗、拉米夫定治疗和联合治疗后的慢性HBV变异情况进行比较,进行统计学分析.结果干扰素和拉米夫定治疗慢性乙型肝炎都可引起前C区A83点突变和YMDD变异,干扰素引起的变异以前C区A83突变为主,拉米夫定引起的变异以YMDD变异为主,而联合治疗则较少引起HBV变异,差异有统计学意义(P＜0.05).结论HBV变异是药物治疗选择的结果,干扰素、拉米夫定治疗后使变异株成为优势毒株,药效下降,病毒DNA滴度反跳,拉米夫定联合干扰素治疗HBV,基因变异机会则相对较少.     

慢性乙型肝炎拉米夫定耐药患者HBV基因型及ALT变化的观察

观察慢性乙型肝炎患者用拉米夫定治疗后HBVP基因变异与不同HBV基因型感染及HBV DNA复升水平和转氨酶变化.收集51例慢性乙型肝炎患者用拉米夫定治疗52-78周后发生YMDD变异的血清标本,对照组128例未用拉米夫定治疗的慢性乙型肝炎患者血清标本,应用聚合酶链反应方法,测定HBV DNA基因型;用限制性片段长度多态性分析方法(PCR RELP)测定HBV DNA YMDD变异;同时进行HBV DNA定量分析.结果显示51例拉米夫定治疗后HBV DNA基因变异患者以B型和C型为主,分别为10例(19.6%)和39例(76.47%),B C混和型2例(3.92%),未见其它基因型.拉米夫定治疗引起HBVDNAYMDD变异可以发生在不同HBV基因型感染的慢性乙型肝炎患者中,与对照组比较二者没有显著性差异.     

乙型肝炎

包膜蛋白突变对乙型肝炎病毒包装的影响；乙型肝炎病毒YMDD变异与肝功能损伤程度的关系；实时荧光聚合酶链反应检测HBV基因型方法的建立和临床研究；拉米夫定治疗慢性乙型肝炎YMDD变异的产生与病毒载量的关系；高通量乙型肝炎病毒YMDD突变区焦磷酸测序方法的建立及其可靠性研究.     

乙型肝炎病毒基因型与YMDD变异的关系

目的:了解乙型肝炎病毒(HBV)基因型与YMDD变异之间的关系.方法:多对型特异性引物PCR扩增法对238例经拉米夫定治疗的慢性乙型肝炎患者进行HBV基因分型,直接序列分析;采用基因芯片检测YMDD及前C/BCP区变异.结果:238例患者中,检测出B基因型190例(79.8%),C基因型41例(17.2%),BC混合型7例(3.0%);发生YMDD变异44例,变异率为18.5%,其中B基因型33例,变异率为17.4%,C基因型8例,变异率为19.5%,BC混合型3例,变异率为42.4%,C基因型YMDD变异的发生率与B基因型相比,差异无显著性意义(P＞0.05).44例YMDD变异者中,30例同时存在L528M变异,7例联合前C区(nt 1 896)变异,13例联合BCP区(nt 1 762/1 764)双重突变.结论:本地区慢性乙型肝炎患者中,优势基因型为B型和C型,经拉米夫定治疗后YMDD变异的发生率在B型和C型差异无显著性意义,同时伴有L528M及前C/BCP区多重变异.     

拉米夫定治疗慢性乙型肝炎36例临床观察

目的观察拉米夫定治疗慢性乙型肝炎的效果。方法36例患者,采取拉米夫定治疗,分别于12月和24个月时观察ALT复常率,HBV DNA转阴率及HBeAg转阴率,同时检测YMDD变异的情况。结果拉米夫定治疗1年的HBV DNA、HBeAg转阴率为别为54.5%、24.2%,HBeAg/抗HBe血清转换率12.1%,ALT复常率78.8%,YM-DD变异率5.6%。停药半年后血清HBV DNA复阳率为22.2%,YMDD变异率18.2%,ALT再次升高率33.3%,死亡1例。结论拉米夫定能够有效降低HBV DNA水平,随着用药时间的延长,YMDD变异的发生率逐渐升高,部份病例停药后出现病情反复或加重。     

慢性乙型肝炎病人出现YMDD变异后继续长期应用拉米夫定的疗效

目的 观察慢性乙型肝炎病人出现YMDD变异后继续治疗的结果。方法 定期观察44例出现YMDD变异后继续长期应用拉米夫定的慢性乙型肝炎病人，项目包括临床表现、ALT、SB、乙型肝炎病毒血清学标志、HBV DNA及YMDD变异情况。结果 88例病人服拉米夫定3年，共有51例出现YMDD变异。48周、104周和168周YMDD变异率分别为21．7％、48％和68．4％。44例继续用药病人按变异后ALT的变化分为3组：ALT值＜1ULN（16例）、＞1－5ULN（21例）和＞5ULN（7例）；HBV DNA中位值分别为0．88、200．93和537．70mEq/ml；血清转换分别为7、1和1例。与无病毒变异组的血清转换率61．1％相比，变异后ALT正常组43．8％（P＞0．05），变异后ALT异常组为7．1％（P＜0．01）。结论 拉米夫定对大多数YMDD变异的慢性乙型肝病人仍有效，但须在严密监测下使用。     

拉米夫定治疗慢性乙型肝炎过程中HBV YMDD变异及基因芯片检测

建立乙型肝炎病毒变异基因诊断芯片对拉米夫定治疗慢性乙型肝炎过程中出现的肝炎病毒P基因区YMDD变异进行快速准确的检测方法。设计特异性寡核苷酸探针数组 ,特殊处理芯片载体。用点样法制备乙型肝炎病毒变异基因诊断芯片。在本院住院治疗病人中选择 3 0例服用拉米夫定后 ,可能出现YMDD变异的病人进行基因芯片杂交检测分析 ;同时用PCR直接测序法对上述 3 0例病人血清标本进行双盲HBVDNA聚合酶活性区域测序对照。 3 0例服药后HBVDNA反跳病人中 ,基因芯片测得HBVYMDD变异 2 1例 ,其中YVDD变异 11例。YIDD变异 10例。HBVDNAPCR直接序列测定结果与基因芯片检测结果完全一致。乙型肝炎病毒变异基因诊断芯片可以同时检测YVDD、YIDD变异 ,同PCR直接测序法比较 ,准确率达 10 0 % ,无假阳性     

乙型肝炎病毒基因型、YMDD变异与拉米夫定治疗后HBV DNA反弹关系的研究

目的探讨HBV基因型、YMDD变异与拉米夫定抗病毒治疗后HBV DNA反弹的关系。方法应用多引物对巢式PCR法、PCR-序列分析法检测拉米夫定治疗的27例乙型肝炎患者和19例从未用过抗病毒治疗的患者HBV基因型和P区（YMDD）的突变位点。结果在27例HBV DNA反弹的患者中，13例（48．15％）检出YMDD变异，而对照人群无YMDD变异（P〈0．05）。YMDD变异的位点为rtM204V／I（C区）±rtL180M（B区）；在治疗组YMDD变异的患者中，B、C基因型构成比（46．15％和59．26％）与对照组（53．85％和68．42％）比较无显著性差异（P〉0．05）。结论YMDD变异是拉米夫定治疗后出现耐药导致HBV DNA反弹的主要原因；YMDD变异的常见位点依然为rtM204V／I（C区）±rtL180M（B区）；YMDD变异在B、C基因型病人中无差别。     

拉米夫定治疗前后乙型肝炎病毒YMDD变异的相关因素分析

目的 了解遵义地区HBV基因型以及拉米夫定治疗前后发生YMDD变异的相关因素,及早进行拉米夫定疗效及耐药的预测. 方法 53例慢性乙型肝炎患者分别在口服拉米夫定前及治疗后3、6、12、18、24个月进行血清HBV DNA定量、乙型肝炎标志物、ALT、AST、总胆红素,白蛋白的检测.同时在接受拉米夫定治疗前采用基因测序法检测HBV基因型及YMDD变异株,治疗后HBV DNA定量下降又反弹升高,且血清HBV DNA＞1×104拷贝/ml时,再次进行YMDD变异株检测.率的比较用卡方检验及确切概率法,两组均数之间比较采用独立样本t检验,有序变量之间的比较采用秩和检验.结果 遵义地区的HBV基因型由B、C及B+C基因型构成.拉米夫定治疗后18例检出YMDD变异株,用药1年和2年的变异率分别为15.1%和34.0%.HBV突变类型有rtL180M/M204V、rtL180M/M204I、rtM204I和rtL180M四种,其中C区rtM204V全部合并rtL180M突变(100%),C基因型中rtL180M/M204V联合突变及rtL180M/M204I联合突变明显高于B基因型(77.8%比25.0%及22.2%比12.5%);C基因型中未见点突变,而rtM204I、rtL180M的点突变仅见于B基因型.YMDD变异与未变异组性别、民族、乙型肝炎家族史及HBeAg情况差异无统计学意义(P＞0.05),病程≥2年组和年龄＜35岁组变异率明显升高(X2值分别为4.707和5.853,P值均＜0.05).不同HBV DNA滴度患者YMDD变异率差异无统计学意义(X2=0.801,P＞0.05),但HBV DNA＜105拷贝/ml者未发现YMDD变异.结论 拉米夫定治疗后YMDD变异可能与HBV基因型及P基因突变类型有关,并随治疗时间的延长而增加.为了减少YMDD变异的发生,应选用病程短、HBV DNA水平较低、肝损害较重的患者进行拉米夫定治疗,有条件的应检测HBV基因型.     

Reversion from precore/core promoter mutants to wild-type hepatitis B virus during the course of lamivudine therapy

The effect of lamivudine administration on the evolution of precore/core promoter mutation is unknown. The aim of this study was to determine the changes of precore/core promoter sequences in chronic type B hepatitis patients treated with lamivudine. Serial sera were obtained from 11 patients before, at the beginning of, and during therapy. Serum samples were polymerase chain reaction-amplified, and nucleotide sequences of hepatitis B virus (HBV) were analyzed. At baseline, precore and core promoter mutations were found in 6 and 4 of 11 patients, respectively. A precore stop codon mutant was replaced by a wild-type virus in all 6 patients infected with precore mutant at a median treatment of 12 months (vs. before therapy; P =.011). Mutations in the core promoter appeared in only 1 of 10 patients (vs. before therapy; P =.021). However, precore and core promoter mutations appeared in 5 and 7 of 10 patients at a median treatment of 21 months, respectively. Acute exacerbation occurred after lamivudine withdrawal in 2 patients who had hepatitis B e antigen (HBeAg) loss or seroconversion. The serum remained HBeAg-negative throughout the study period, and each of 2 patients had precore wild-type virus during acute exacerbation. HBV mutants with core gene deletions are not eliminated completely during prolonged therapy in 2 patients in whom the HBV genomes had core gene deletions at baseline. In conclusion, lamivudine therapy resulted in reversion from precore/core promoter mutants to wild-type. However, mutations in the precore and core promoter region reappeared during prolonged therapy. HBeAg-negative wild-type precore hepatitis B virus could be selected after lamivudine withdrawal in patients who had HBeAg loss or seroconversion.     

Evolution of hepatitis B virus precore/basal core promoter gene in HBeAg‐positive chronic hepatitis B patients receiving lamivudine therapy

Aim: Lamivudine is effective in hepatitis B e antigen (HBeAg)‐positive chronic hepatitis B, but the relapse rate after cessation of treatment is high. The evolution of viral genome may contribute to the viral replication under antiviral pressure of lamivudine. We therefore determined the evolution of hepatitis B virus (HBV) precore/basal core promoter and polymerase genes in HBeAg‐positive chronic hepatitis B patient during lamivudine therapy. Method: Thirteen patients with HBeAg‐positive chronic hepatitis who had received short‐term lamivudine therapy (mean, 30 weeks) during 1999–2001 were enrolled. The precore/basal core promoter region and polymerase gene were amplified and directly sequenced before, during and post lamivudine treatment. Result: HBeAg loss or seroconversion occurred in 11, but eight relapsed after stopping therapy and five had reversion of HBeAg. Before treatment, basal core promoter mutation was found in 1. In the first 3 months of therapy, a rapid decline of serum HBV DNA level accompanied with basal core promoter mutation appeared in 11 of 13 patients (vs. before therapy; P=0.003). However, this mutant was replaced by wild‐type virus in four of eight patients who relapsed after treatment. There was no significant change of precore sequences before and during therapy. Conclusions: Lamivudine therapy may result in the rapid development of basal core promoter mutation of HBV, but this mutation may revert to wild type gradually after cessation of therapy.     

Association of mutations in the core promoter and precore region of hepatitis virus with fulminant and severe acute hepatitis in Japan

It was recently reported that mutations in the precore and core promoter region of hepatitis B virus (HBV) are associated with fulminant hepatitis. The aim of this study was to investigate the association of mutations in the precore and core promoter region of HBV with fulminant and severe acute hepatitis. We studied Japanese patients with acute HBV infection, including seven patients with fulminant hepatitis, 12 with severe acute hepatitis and 41 with acute self-limited hepatitis. The presence of HBV mutants was examined by using a point mutation assay to detect a G to A transition at position 1896 in the precore region and an A to T transition at position 1762 and a G to A transition at position 1764 in the core promoter region. Significant differences in the proportion of mutations in the precore or core promoter region were present between patients with fulminant hepatitis and self-limited acute hepatitis (7/7 (100%) vs 4/41 (9.8%), P < 0.01) and between severe acute hepatitis and self-limited acute hepatitis (6/12 (50.0%) vs 4/41 (9.8%), P < 0.01). The frequency of mutation increased proportionately with the severity of disease in patients with acute HBV infection. Fulminant hepatitis B in Japan is closely associated with mutations in the core promoter and precore gene of HBV. Point mutation assays for HBV precore and core promoter analysis may be useful to predict the outcome of liver disease in patients with acute HBV infection.     

Evolution of hepatitis B virus polymerase gene mutations in hepatitis B e antigen-negative patients receiving lamivudine therapy

Lamivudine has been shown to be effective in patients with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B, but its long-term efficacy and the rate of resistant mutations in patients with HBeAg-negative chronic hepatitis B is less clear. Twenty-nine patients with HBeAg-negative chronic hepatitis B, who have received lamivudine for at least 1 year were studied to determine the antiviral response, the rate and pattern of lamivudine-resistant mutations, and the effect of lamivudine-resistant mutations on HBeAg status. The mean duration of treatment was 21 +/- 7 months. Before treatment, core promoter variant was detected in 16 (55%) patients and precore stop codon variant in 18 (62%) patients. Serum hepatitis B virus (HBV) DNA was detected by solution hybridization assay in 62%, 4%, and 24% and by polymerase chain reaction (PCR) assay in 100%, 31%, and 40% at months 0, 6, and 24, respectively. The cumulative rates of detection of lamivudine-resistant mutations after 1 and 2 years of treatment were 10% and 56%, respectively. In addition to the duration of treatment, core promoter mutation was associated with the selection of lamivudine-resistant mutants. Three patients with lamivudine-resistant mutations had reversion of the precore stop codon mutation; in 2 patients this was accompanied by the reappearance of HBeAg. We found that lamivudine-resistant mutants were detected at similar rates in patients with HBeAg-negative as in patients with HBeAg-positive chronic hepatitis B. Additional changes in other parts of the HBV genome may restore the replication fitness of lamivudine-resistant mutants.     

Mutations of polymerase,precore and core promoter gene in hepatitis B virus during 5-year lamivudine therapy

BACKGROUND/AIMS: The effects of long-term lamivudine therapy on changes in polymerase and precore/core promoter mutations are unknown. The aim of this study was to determine the changes in these regions in patients with chronic hepatitis B virus (HBV) infection treated with lamivudine for 5 years. METHODS: Serum samples obtained from 16 patients at the beginning of and during therapy were polymerase chain reaction-amplified, and nucleotide sequences of HBV analyzed. RESULTS: By the end of 5-year therapy, mutations in YMDD motif emerged in ten patients. Mutations in L526M, M550V and M550I in polymerase were found in seven, six and six patients, respectively. The L526M mutant was found at the time or after detection of M550V/I mutant in six of seven patients. At baseline, precore and core promoter mutations were found in eight and 12 of 16 patients, respectively. Mutants of precore and core promoter were replaced by wild-type virus in each of three patients infected with mutants at 1 year. However, at 5 years of treatment, precore and core promoter mutations reappeared in some patients. CONCLUSIONS: Our data showed that lamivudine initially selected from precore/core promoter mutants to wild-type virus, but precore mutation reappeared during prolonged therapy.     

Hepatitis B genotypes and precore/basal core promoter mutants in HBeAg-negative chronic hepatitis B

Background. Mutations in the precore stop codon (G1896A) and the basal core promoter (A1762T and G1764A) are frequently found in hepatitis B envelope antigen (HBeAg)-negative chronic hepatitis B. However, the clinical significance of these mutations remains controversial. We therefore investigated the influence of hepatitis B virus (HBV) genotypes, as well as precore/basal core promoter mutants, on the clinical and virological features of patients with HBeAg-negative chronic hepatitis B. Methods. Serum samples from 37 patients with HBeAg-negative chronic hepatitis B were collected for serological and molecular assays. The precore and basal core promoter regions were amplified by polymerase chain reaction and the amplicons were directly sequenced and analyzed. HBV geno-type was determined by polymerase chain reaction-restriction fragment length polymorphism. Results. Most of the patients had detectable serum HBV DNA, and genotypes B and C were the predominant strains. The overall prevalence of the precore stop codon mutant and basal core promoter mutant was 67% and 60%, respectively. The baseline clinical and virological features of patients with genotype B and genotype C infection were comparable. However, in the patients with precore/basal core promoter dual mutations there was a significantly lower proportion of individuals with a high detectable serum HBV DNA level (>100 pg/ml) than in the patients with either the precore stop codon mutation alone or the basal core promoter mutation alone (P = 0.04 by the logistic regression test for the trend). Conclusions. Our data suggest a high prevalence of precore stop codon and basal core promoter mutation in Taiwanese patients with HBeAg-negative chronic hepatitis B, and the influence of the basal core promoter mutation on HBV replication is modulated by the emergence of the precore stop codon mutation. Received: May 14, 2001 / Accepted: September 14, 2001     

Different hepatitis B virus genotypes are associated with different mutations in the core promoter and precore regions during hepatitis B e antigen seroconversion

Mutations in the core promoter and precore regions are frequently found in hepatitis B e antigen (HBeAg)-negative patients, but precore stop codon mutation is restricted to hepatitis B virus (HBV) genotypes that have T at nucleotide 1858. The aims of this study were to determine the role of core promoter and/or precore mutations in HBeAg seroconversion and their impact on the subsequent course of liver disease, and to determine if core promoter mutations are more frequently selected in patients with HBV genotypes that preclude the development of precore stop codon mutation. Serial sera from 45 patients with chronic HBV infection were polymerase chain reaction (PCR)-amplified, and the HBV core promoter and precore regions were sequenced. Ninety-two percent of patients had core promoter or precore mutations after HBeAg seroconversion: 42% had core promoter changes only, 38% had precore stop codon mutations only, and 12% had changes in both regions. Seventy-three percent of the patients had persistently normal aminotransferases, and only 8% had multiple flares in aminotransferases after HBeAg seroconversion. Core promoter changes were significantly more common in patients infected with HBV who have C at nucleotide 1858 (91% vs. 27%; P <.01), while precore stop codon changes were exclusively found in patients infected with HBV who have T at nucleotide 1858 (87% vs. 0; P <.01). The vast majority of our patients had core promoter and/or precore mutations after HBeAg seroconversion. Nevertheless, most patients had sustained remission of liver disease. Our data suggest that core promoter changes are preferentially selected in patients infected with HBV genotypes that preclude the development of precore stop codon mutation.     

Precore and core promoter mutations of hepatitis B virus and hepatitis B e antigen-negative chronic hepatitis B in Korea

BACKGROUND/AIMS: The aims of this study were to determine the frequency of precore/core promoter mutations and hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (e-CHB) in Korea. METHODS: Patients with chronic hepatitis B virus (HBV) infection were tested for HBeAg, anti-HBe, liver profile and HBV-DNA by a branched DNA (bDNA) assay. Serum HBV-DNA was amplified by a polymerase chain reaction and the precore/core promoter sequence was determined. RESULTS: Among the 413 consecutive HBeAg-negative patients, 19.6% were bDNA-positive. Evidence of liver disease was found in 90.1% of bDNA-positive and 41.7% of bDNA-negative patients. Overall, 17.7% of HBeAg-negative patients had e-CHB. Precore mutation (A1896) was detected in 93.7% of HBeAg-negative bDNA-positive and 93.9% of HBeAg-negative bDNA-negative patients. In 59 HBeAg-positive patients, 78% had wild-type and 22% had a mixture of wild-type and A1896 mutant. Core promoter TA mutation was detected in 89.9% of HBeAg-negative bDNA-positive patients, 89.8% of HBeAg-negative bDNA-negative patients, and 74.6% of HBeAg-positive patients. No correlation was found between the presence of precore/core promoter mutations and HBV-DNA levels or disease severity. CONCLUSIONS: In Korean patients infected with HBV genotype C, precore mutation occurred almost invariably along with HBeAg seroconversion and core promoter TA mutation was frequent irrespective of viral replication levels or disease severity.     

Lamivudine resistance in patients with chronic hepatitis B: role of clinical and virological factors

BACKGROUND: Lamivudine resistance is associated with long-term monotherapy for chronic hepatitis B and can lead to potentially serious clinical consequences. Scant information exists regarding the influence of hepatitis B virus variants in the development of resistance. The present study was designed to identify factors predictive of lamivudine resistance, with a particular focus on the role of precore and basal core promoter variants in the setting of hepatitis B e antigen-negative disease. METHODS: Eighty-five patients, representing four major genotypes, were followed prospectively on lamivudine therapy. Resistance was defined as an increase in viral load, with polymerase gene sequencing confirming a lamivudine resistance mutation. Median follow up was 19 months (6-54 months). The Cox proportional hazards model was used to determine variables independently predicting for the early onset of lamivudine resistance. RESULTS: The rate of lamivudine resistance was 6%, 31% and 51% at 12, 24 and 48 months, respectively. Multivariate analysis identified the precore variant, high baseline alanine aminotransferase (ALT), and persistent viremia (at 6 months) as independent predictors of the early development of lamivudine resistance, with rate ratios of 4.93 (95% confidence interval [CI]: 1.32-18.5), 1.22 (95%CI: 1.08-1.49), and 4.73 (95%CI: 1.49-15.0), respectively (P < 0.05). Female sex predicted early resistance (rate ratio 5.27 [95%CI: 1.23-22.5, P < 0.05]) although numbers were small (n = 12). Genotype did not influence treatment response nor time to onset of resistance. CONCLUSION: Patients with precore variant hepatitis B virus are likely to develop lamivudine resistance early and should be considered for alternate first-line monotherapy. In the future, combination antiviral therapy may limit the development of resistance.     

HBV C基因启动子变异及基因型与肝硬化的相关性研究

目的探讨乙型肝炎病毒(HBV)C基因启动子(CP)和前C区基因变异及HBV基因型与肝硬化的关系。方法通过DNA扩增、基因序列分析检测44例慢性乙型肝炎(CH)、29例肝硬化(LC)患者的血清HBVS基因序列确定其基因型,测定HBVCP和前C区序列确定其变异状况。结果LC患者CP双变异(nt1762A→T和1764G→A)发生率(72.4%)显著高于CH(45.5%),P<0.05;LC患者C型检出率(69.0%)显著高于CH(43.2%),P<0.05;C型HBV感染者的CP双变异发生率(69.2%)显著高于B型感染者(44.1%),P<0.05。结论CP双变异与C基因型密切相关,并且导致病情向肝硬化发展。