慢性乙型肝炎病毒感染者病毒YMDD的自然变异

目的 了解慢性HBV感染患者外周血HBV YMDD自然变异情况及其影响因素.方法 采用引物特异性实时荧光PCR法检测慢性HBV感染者外周血HBV YMDD变异情况,并对影响YMDD自然变异检出率的可能因素进行单因素及多因素分析.根据不同资料分别采用χ~2检验、Fisher's确切概率法、t检验、秩和检验及Logistic回归分析进行统计学处理. 结果在196例未经抗病毒治疗的慢性HBV感染者中,检出存在YMDD自然变异株感染者21例(10.70%),其中YVDD阳性20例,YIDD阳性例1变;变异毒株占总病毒株超过50%者1例,25%～500者5例,9%～25%者15例.B基因型HBV感染病例中YMDD变异株的检出率(20.00%,12/60)显著高于C基因型HBV感染病例(7.38%,9/122),χ~2=6.28,P<0.05.患者性别、年龄、HBeAg状态、HBVDNA载量、疾病状态、病毒感染时间对YMDD自然变异株的检出率无显著影响. 结论 在未经抗病毒治疗的慢性HBV感染者中存在HBV YMDD自然变异;YMDD自然变异的发生率与患者性别、年龄、HBeAg状态,HBV DNA载量、疾病状态、感染时间无显著相关性.B基因型较C基因型HBV更易出现YMDD自然变异.     

HBeAg阳性和阴性慢性乙型肝炎患者YMDD的变异

目的研究YMDD变异在HBeAg阳性和HBeAg阴性乙型肝炎病毒（HBV）感染者中发生的情况.方法对我科接受拉米夫定治疗的247例慢性乙型肝炎患者进行定期随访,检测肝功能和HBV病毒学指标,利用聚合酶链反应-限制性片段长度多态性（PCR-RFLP）检测YMDD变异,利用实时定量PCR检测HBV DNA定量以及利用Abbott试剂检测HBV标志物,对比分析HBeAg阳性和HBeAg阴性患者中YMDD变异的发生情况.结果247例患者中共有42例出现YMDD变异,YMDD变异的累积发生率随着时间的延长逐年增加.与治疗前HBeAg阴性患者相比,治疗前HBeAg阳性患者YMDD变异的发生率明显高于治疗前HBeAg阴性患者.结论HBeAg阳性患者YMDD变异年累积发生率高于HBeAg阴性患者.     

未接受抗病毒治疗的慢性乙型肝炎患者多聚酶P基因YMDD变异检测

目的 了解未经拉米夫定及干扰素抗病毒治疗的慢性乙型肝炎患者中HBV多聚酶YMDD变异情况。方法 应用错配PCR扩增方法检测病人血清HBV的YMDD位点，选择65例病史超过半年以上、肝功能异常、HBV DNA阳性的慢性乙型肝炎患者。结果 在65例患者中，YMDD变异阳性6例(9．07％)，阴性59例，6例变异中2例为YIDD阳性，其中1例为YMDD野毒株和变异株混合存在，4例为YYDD阳性，其中1例为YMDD野毒株和变异株混合存在。结论 本检测方法简便、实用，在未经抗病毒治疗的慢性乙型肝炎患者中可存在YMDD变异株，其与野生株一样是自然存在的。     

拉米夫定耐药变异株在急性HBV感染者中的流行调查

目的:调查YMDD变异株在急性HBV感染(AHB)中的流行情况,为指导AHB的防治提供依据.方法:收集HBV感染者321例(HBV DNA≥1.0×107copies/L),其中未开始治疗的AHB患者100例和拉米夫定治疗(100 mg/d)不同时期的CHB患者221例.采集外周血标本,用荧光标记杂交双探针PCR融解曲线法(FH-PCR-MC)检测血清HBV YMDD及其变异,统计分析HBVYMDD变异在两组中的分布.结果:在AHB组,只检出HBV YMDD野生型,未检出变异型.而在CHB组,YMDD变异检出率为63.4%,其中YIDD占52.1%,YVDD占37.9%,YIDD+YVDD混合变异占10.0%:1年内、1-2年、2-3年、3-4年和4年以上疗程YMDD变异率分别为45%,66%,77%,75%和40%,YMDD变异检出率在两组中差异显著(X2=112.3,P=0.00).结论:目前在用拉米夫定治疗的CHB患者中仍有较高比率的YMDD变异株存在,但尚未发现该变异株在AHB患者中流行.     

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.     

拉米夫定与HBV YMDD耐药变异及临床相关因素分析

目的:用PCR-RFLP方法检测慢性乙型肝炎患者HBV-YMDD变异发生的情况,并分析与YMDD变异发生有关的因素。方法:从慢性乙型肝炎患者血清中提取的HBV DNA,扩增HBV多聚酶YMDD主型区核苷酸序列,用针对突变位点的特异限制性内切酶酶切扩增产物,经6％聚丙烯酰胺凝胶电泳后用限制性片段长度多态性技术鉴定HBVYMDD变异。结果:在152例慢性乙型肝炎患者中,72例单用拉米夫定治疗、41例接受拉米夫定与干扰素联合治疗、39例未接受拉米夫定治疗的患者,HBV YMDD变异检出率分别是47.2％、19.5％、7.7％;72例单用拉米夫定治疗的患者,36例治疗2周～6个月、20例治疗7～12个月、16例治疗13～27个月,HBV YMDD变异检出率分别是25％、55％、87.5％。结论:在使用拉米夫定治疗慢性乙型肝炎的过程中可发生YMDD耐药变异,且随拉米夫定治疗时间的延长,变异发生率增加,但拉米夫定与干扰素联合进行抗病毒治疗可延迟或阻滞YMDD变异的发生。HBVYMDD变异可能自然存在或发生。HBV基因组其他位点的变异也可能使HBV对拉米夫定产生耐药性。     

慢性乙型肝炎患者血清中病毒的YMDD自然变异

近年来,随着拉米夫定的广泛应用,部分患者出现YMDD变异而产生耐药性,最常见的有YVDD(M552V)和YIDD(M552I)变异.因此,服用拉米夫定后患者的YMDD变异成为近几年的研究热点[1-2];但有研究证实存在YMDD自然变异[3].国内目前尚缺乏大样本YMDD自然变异率的研究,我们对未经治疗的449例慢性乙型肝炎患者进行YMDD变异株的检测,探讨了不同慢性乙型肝炎患者血清中HBV YMDD的自然变异率及其与血清HBV DNA水平的关系.     

乙型肝炎病毒YMDD变异患者肝组织中HBsAg、HBcAg表达的比较

长期服用拉米夫定治疗慢性乙型肝炎,可引起HBV YMDD变异.HBV YMDD变异是指病毒DNA聚合酶活性区的第204位或551位甲硫氨酸(M)发生突变,被缬氨酸或异亮氨酸取代,是导致HBV对拉米夫定耐药、治疗失败或HBV无应答的原因[1-3].拉米夫定治疗失败主要表现为患者肝功能损伤、肝脏组织学病理变化和病情复发甚至加重[4,5].为了比较HBV YMDD变异患者肝组织中HBsAg、HBcAg表达的差异,我们对2004至2005年发生YMDD变异的45例慢性乙型肝炎患者进行了相关研究,现报道如下.     

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。     

YMDD motif variants in inactive hepatitis B carriers detected by Inno-Lipa HBV DR assay

INTRODUCTION: Mutations of hepatitis B virus (HBV) polymerase, especially occurring at the highly conserved YMDD region, are related to resistance to lamivudine. Although these mutations are frequently secondary to lamivudine use, they can also occur naturally. The aim of the present study was to determine the prevalence of YMDD variants that exist naturally in patients who are inactive HBV carriers. METHODS: Seventy-one adult inactive HBV carriers were studied. All of the patients were confirmed to have maintained normal alanine aminotransferase (ALT) values for one or more years by monitoring serum ALT levels at 3-monthly intervals. None of the patients received interferon or antiviral agents. YMDD variants were analyzed by the HBV Drug Resistance Line Probe assay (Inno-Lipa HBV-DR). RESULTS: YMDD variants were detected in 13 (18.3%) of the 71 anti-HBe positive inactive HBV carriers. Of the 13 patients, 10 (76.9%) also had accompanying L180M mutation. The combination of wild type and YMDD variant HBV was present in 11 of 13 patients. In two patients, only YIDD and/or YVDD variants plus L180M were detected without the presence of wild YMDD motif. CONCLUSION: Naturally occurring YMDD motif variants were detected at a high rate in a group of lamivudine-untreated inactive HBV carriers.     

拉米夫定相关性HBV变异对乙型肝炎预后的影响

目的 进一步探讨拉米夫定相关性ＨＢＶ变异对患者临床经过的影响。方法 将接受拉米夫定治疗１００ｍｇ／ｄ的８２例患者在第１０４周按其发生变异程序分为完全变异、部分变异和无变异３组,分别进行肝功能和血清学指标比较。结果 在第１０４周,Ｆ和Ｍ组无１例ＨＢｃＡｇ阴国专,而Ｎ组有１８例ＨＢｅＡｇ阴转 ,１１例ｃＡｇ／抗－ＨＢｅ血清转换;拉米夫定相关性ＨＢＶ变异发生后ＡＬＴ可增高,完全变异组Ｈ ＢＶＤＮＡ水平明     

乙型肝炎病毒前C基因区变异对YMDD变异毒株复制活性的影响

目的调查接受拉米夫定治疗的乙型肝炎病毒（HBV）感染者中HBV前C基因区终止密码变异（A1896，PC）和基本核心启动子变异（BCP，T1762／A1764）对YMDD变异毒株复制活性的影响。方法应用聚合酶链反应-限制性片断长度多态性（PCR—RFLP）法对197例接受拉米夫定治疗后发生YMDD耐药变异的患者进行HBV基因型、PC及BCP变异检测，并用实时荧光定量法对所有患者血清HBVDNA进行定量。结果197例YMDD变异株感染者中B基因型占51．8％，C基因型占48．2％；有61例（31．0％）发生PC变异，69例（35．0％）发生BCP变异；PC变异在B基因型中的发生率明显高于C基因型（X^2=8．433，P=0．004），而BCP变异在C基因型中的发生率显著高于B基因型（X^2=16．83，P〈O．001）；发生PC或BCP变异的HBV感染者，其血清中HBVDNA水平与野生株相比差异均无统计学意义。结论HBV前C基因区的PC或BCP变异与基因型具有相关性，但这两种变异对YMDD变异株感染者的血清病毒水平均无影响。     

Occult HBV infection and YMDD variants in hemodialysis patients with chronic HCV infection

BACKGROUND/AIMS: End-stage renal disease patients on chronic hemodialysis are at risk for both hepatitis B virus (HBV) and hepatitis C virus (HCV) infection. Although the prevalence is unknown in hemodialysis patients, occult HBV infection is frequent in subjects with chronic HCV infection. We aimed to investigate (1) the prevalence and clinical impact of occult HBV infection in hemodialysis patients with chronic HCV infection, and (2) the frequency of YMDD variants (tyrosine-methionine-aspartate-aspartate amino acid motif of HBV polymerase) in this setting. METHODS: Thirty-three anti-HCV and HCV-RNA-positive, HBsAg-negative hemodialysis patients (mean age 36.9+/-10.4 years, 22 male) were admitted to this study. HBV-DNA (Innogenetics kit) and HCV-RNA (Cobas Amplicor HCV kit) were investigated by polymerase chain reaction technique (PCR). YMDD mutation was studied in all HBV-DNA-positive patients by the BOOM method. RESULTS: HBV-DNA was detected in 12 of 33 patients (36.4%) by PCR. Their mean age was 33.0+/-9.0 years. Age, dialysis period (years) and biochemical parameters were not significantly different in patients with and without occult HBV infection. YMDD variants were identified in six of 12 (50%) patients with occult HBV infection. CONCLUSIONS: Occult HBV infection is frequent in hemodialysis patients with chronic HCV infection. YMDD variants are common in this setting.     

慢性乙型肝炎YMDD变异患者的临床与病理诊断分析

目的探讨慢性乙型肝炎发生YMDD变异时临床诊断与病理诊断的符合性,血清HBV DNA与病理分度的关系。方法对42例YMDD变异的慢性乙型肝炎患者进行测定HBV DNA、肝活检;进行临床诊断与病理诊断对比,作Kappa分析。设37例没有服用拉米夫定无YMDD变异患者为对照组,比较两组间病毒复制情况与病理分度。结果YMDD变异患者临床诊断与病理诊断总符合率为66.7%,慢性乙型肝炎轻度、中度、重度分别为83.3%、40.0%、66.7%,Kappa值=0.346,P<0.01。与对照组比较,肝组织病变程度轻,病理诊断中、重度肝炎少。结论发生YMDD变异时,慢性乙型肝炎病情活动的临床诊断与病理诊断一致性不强,因此,对没有禁忌证的患者应行肝活检,特别是中、重度肝炎患者更应该接受肝活检。慢性乙型病毒性肝炎抗病毒治疗是重要和有效的治疗手段。     

慢性乙型肝炎患者拉米夫定治疗24周时YMDD变异对疗效的影响

目的 使用基因芯片方法检测乙型肝炎病毒(HBV)YMDD变异的发生情况,研究YMDD变异发生与肝功能损伤和HBV复制水平指标之间的关系。方法 120例以常规剂量(100mg/d)口服拉米夫定的慢性乙型肝炎患者,治疗前和治疗第24周抽取血清检测丙氨酸氨基转移酶(ALT)、HBV DNA(定量)水平,对24周HBV DNA阳性的17例患者血清样本,以基因芯片方法检测其治疗前和治疗24周时血清中YMDD变异是否存在,并分析该变异发生和ALT、HBV DNA的关系。结果 (1)120例入选患者治疗24周时有17例患者HBV DNA仍为阳性,除外治疗前已存在的1例感染变异病毒,基因芯片共检出7例变异,变异率为5.8％。其中纯变异2例,YIDD变异1例,YVDD变异1例,混合变异5例,其中YMDD/YVDD变异3例,YVDD/YMDD变异2例。(2)变异组在治疗前和治疗24周时ALT定量水平与非变异组相比,差异无显著性,P>0.05。(3)变异组在治疗前和治疗24周时HBV DNA定量水平与非变异组相比,差异无显著性,P>0.05。结论 在拉米夫定治疗过程中,YMDD基因变异发生对肝脏炎症活动度和病毒复制的抑制作用无显著影响。     

A 7‐year study of lamivudine therapy for hepatitis B virus e antigen‐positive chronic hepatitis B patients in China

OBJECTIVE: To evaluate the long‐term efficacy and safety of lamivudine treatment for chronic hepatitis B and the impact of emergence of YMDD mutation of hepatitis B virus (HBV). METHODS: A total of 429 patients with serum HBsAg, HBeAg and HBV DNA positive were randomized to receive either lamivudine 100 mg daily or a placebo in a 3:1 ratio for the first 12 weeks. Thereafter, all patients were administered with lamivudine 100 mg/d for 5 years and followed up for 2 years. RESULTS: After 12 weeks of the lamivudine treatment, serum HBV DNA levels decreased rapidly and HBV DNA negativity (<1.6 pg/mL) was 92.2%, whereas it was only 14.1% (P < 0.01) in the placebo group. At the end of 5 years, serum HBV DNA continued to be substantially suppressed. The loss of HBeAg and seroconversion were significantly correlated with baseline alanine aminotransferase (ALT) levels, in patients with baseline ALT > 2 × upper limits of normal, the loss of HBeAg was 54% and seroconversion rate was 50%, respectively. YMDD mutation developed in 70.8% of the patients at years 5. In YMDD mutant patients, HBV DNA levels were increased moderately and with mild to moderate elevations of ALT. ALT flares (ALT > 5ULN) occurred in 22 patients, 16 with YMDD variants and six with non‐variants. One year durability of seroconversion after stopping lamivudine was 80%. CONCLUSION: Lamivudine is effective and tolerable for chronic hepatitis B.     

Acute, hepatitis-A super-infection in HBV carriers, or chronic liver disease related to HBV or HCV

The impact of acute super-infection with hepatitis A virus (HAV) was determined in 20 asymptomatic carriers of the surface antigen (HBsAg) of hepatitis B virus (HBV), eight patients with HBV-related chronic liver disease (CLD), and four patients with CLD related to hepatitis C virus (HCV). For comparison, 100 patients with isolated HAV infection were also studied. The HBsAg carriers and patients with CLD related to HBV or HCV were significantly older than the patients with isolated HAV infection, with mean (S.D.) ages of 43.9 (14.1), 46.4 (16.0), 52.5 (8.6) and 28.4 (10.7) years, respectively (P < or = 0.02). There were no significant between-group differences in the baseline serum concentrations of alanine aminotransferase. All the patients with isolated HAV infection fully recovered. Fulminant or submassive hepatitis occurred in 11 (55%) of the HBsAg carriers and four (33%) of the 12 patients with CLD related to either HBV or HCV. Nine of the 15 patients with severe hepatitis died and the mortality rate among the HBsAg carriers was not significantly different from that among the CLD patients (25% v. 33%; P = 0.15). These fatal cases were all aged > 50 years and were significantly older [59.0 (2.1) years] than the six severe cases who recovered [43.2 (10.7) years] as well as the remaining 17 uncomplicated cases with CLD or HBsAg [40.3 (13.0) years] (P < or = 0.001). The results indicate that acute HAV is rarely fatal in young adults but may be severe and potentially fatal in patients with underlying chronic HBV or HCV infection, especially among the elderly. Vaccination against HAV should be considered for the patients at high risk who are negative for anti-HAV.     

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