慢性乙型肝炎患者HBV前C区G1896A、核心启动子1762/1764变异与乙型肝炎自然史、血清HBsAg定量及疾病程度的相关性

目的研究HBV前C区G1896A、核心启动子1762/1764变异与HBV自然史、血清HBsAg水平间的相关性及对疾病严重程度的影响。方法分别各选取40例HBV野生株、前C区G1896A或核心启动子1762/1764变异以及两者联合变异的慢性乙型肝炎感染者为研究对象。采用PCR反向点杂交技术检测HBV前C区G1896A位点、核心启动子1762/1764变异及HBV基因分型。同时检测HBsAg定量、HBeAg、HBV DNA定量、肝脏生化指标等。结果(1)HBV前C区G1896A、核心启动子1762/1764变异患者的年龄、ALT高于野生株感染者(P0.001),Alb低于野生株感染者(P0.001)。(2)HBV自然史免疫耐受期以野生株感染为主(P0.001),免疫清除期、低(非)复制期野生株及PC G1896A或/和BCP1762/1764变异株差异无统计学意义(P0.05),再活动期以PC G1896A或/和BCP1762/1764变异株为主(P0.001)。(3)PC G1896A或/和BCP1762/1764变异株的HBsAg水平(lgIu/mL)、HBeAg阳性率较野生株组降低(P0.001),基因C型、HBV DNA水平(≥6 lg拷贝/mL)较野生株组差异无统计学意义(P0.05)。(4)HBV PC G1896A或/和BCP1762/1764变异中肝硬化患者多于野生株(P0.05)。结论慢性HBV感染者前C区G1896A、核心启动子1762/1764变异与乙型肝炎自然史、HBsAg水平、HBeAg的状态及疾病严重程度相关。     

慢性乙型肝炎患者HBV C基因启动子变异的临床意义

目的:探讨慢性乙型肝炎中C基因启动子(BCP)变异的临床意义。方法:采用错配PCR与限制性长度片段多态性分析(RFLP)相结合,检测35例慢性乙型肝炎患者BCP区核苷酸(nt)1762碱基A→T和1764G→A联合突变及前C区nt1896G→A终止变异。结果:在35例慢性乙型肝炎中检出BCP区T1762A1764变异8例(23％),其中6例血清HBeAg( ),2例抗HBe( ),而7例前C区A1896变异中HBeAg( )2例,抗HBe( )5例,未见T1762A1764变异和A1896变异同时出现者。结论:提示HBV毒株BCP区T1762A1764变异可能与前C区A1896变异不同,它的出现不足以导致HBeAg(—)型的慢性肝炎。     

慢性HBV感染者抗病毒治疗前HBV基本核心启动子及前C区突变的检测及意义

目的研究慢性乙型肝炎病毒（HBV）感染者抗病毒治疗前HBV基本核心启动子（BCP）突变和前C区（PreC）突变与HBeAg、HBV DNA水平和慢性肝病进展的关系。方法收集283例慢性HBV感染者抗病毒治疗前的血清标本,其中慢性乙型肝炎（CHB）185例,肝硬化（LC）98例。采用PCR后直接测序法检测HBV BCP和PreC区突变,同时确定基因型。结果在HBeAg阴性和HBeAg阳性CHB患者中,前C区A1896变异率分别为44.6%（37/83）和21.6%（22/102）（χ2=11.154,P=0.001）,LC患者分别为43.4%（23/53）和17.0%（8/47）（χ2=8.101,P=0.004）。在HBeAg阳性患者中,BCP T1762/A1764双突变率LC组和CHB组分别为89.4%（42/47）和70.6%（72/102）（χ2=6.310,P=0.012）。在单变量分析中,只有年龄（≥45岁）（χ2=27.861,P〈0.001）、BCP T1762/A1764双突变（χ2=8.675,P=0.003）和HBV DNA（≥105拷贝/ml）（χ2=20.499,P〈0.001）与LC进展有关。多因素Logistic回归分析（匹配年龄和性别）发现,BCP T1762/A1764双突变（OR=3.260,95%CI：1.401～7.586;wald=7.517,P=0.006）和HBV DNA（≥105拷贝/ml）（OR=4.640,95%CI：2.331～9.237;wald=19.089,P〈0.001）是LC进展的危险因素。结论前C区A1896突变与HBeAg的消失有关;年龄（≥45岁）、BCP T1762/A1764双突变和HBV DNA高载量（≥105拷贝/ml）与肝硬化进展有关。     

乙型肝炎病毒前C区和BCP区突变及基因型对HBeAg表达的影响

研究乙型肝炎病毒前C区和BCP区突变及基因型对HBeAg表达的影响。分别用基因芯片和基因测序的方法检验HBV DNA阳性的乙型肝炎病毒前C区和BCP区突变及基因型,应用时间分辨免疫荧光法检测HBeAg含量,按照有无HBV前C区1896、BCP区1762、1764双突变、基因型等指标进行分组分析。无前C区1896和BCP区1762/1764双突变组、单纯1762、1764双突变和1896突变组以及1896、1762、1764联合突变组之间相互比较,HBeAg含量相差显著,F=6.47,P〈0.01;B、C基因型间HBeAg含量相比,相差无显著性,t=0.1394,P〉0.05。乙型肝炎病毒前C区和BCP区突变能显著影响HBeAg量的表达,从而导致乙型肝炎病毒致病能力的变化。     

乙型肝炎病毒基因型、BCP及PC区变异与拉米夫定治疗后HBV DNA反弹的关系

目的:探讨HBV基因型、C区基本核心启动子(BcP)及前C(PC)区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27例乙型肝炎患者(治疗组),以及19例从未用过抗病毒治疗患者(对照组)的HBV基因型PC区,BCP的突变位点.结果:27例HBV DNA反弹的患者9例检出G1896A变异率高于对照组(33.33% vs 5.26%,P<0.05),4例检出C1856T变异(14.81%).治疗组4份治疗前标本未检出G1896A、C1856T和BCP变异.与对照组比较,治疗组PC(G1896A)及BCP(A1762T G1764A)双变异的患者中B基因型的构成比增高,分别为75%和50%,C基因型的构成比下降,分别为25%和50%.其中在BCP(A1762T G1764A)变异患者中B、C基因型构成比与对照组比较有显著性差异(P<0.05).4例HBV DNA反弹患者治疗前未检出有基因变异,治疗后有2例检出变异,BCP变异1例,BCP PC变异1例.27例HBV DNA反弹患者BCP变异4例,PC变异2例,BCP PC变异8例.结论:BCP(T1762/A1764)变异、PC区(G1896A)变异可能与拉米夫定治疗后HBV DNA反弹有关.病毒变异导致的HBV DNA反弹可以是单基因变异引起,也可以是多个基因联合变异引起,拉米夫定治疗后B基因型患者更易发生A1762T G1764A变异.     

海南汉族乙型肝炎病毒基因型与BCP区和前C区基因突变的关系

目的探讨海南汉族乙型肝炎病毒（HBV）基因型与前C区G1896A和BCP区A1762T／G1764A基因突变的关系。方法采用RT-PCR方法检测乙型肝炎患者的HBV基因型,PCR方法扩增包含C启动子和前C区基因核苷酸（nt1643-nt2112）,对PCR产物进行DNA测序。结果基因型C的BCP区A1762T／G1764A突变率（58．82％）显著地高于基因型B（10．53％）（P〈0．05）。基因型CG1896A突变率为29．41％,基因型BG1896A突变率为47．37％,两者比较差异无统计学意义（P〉0．05）。结论不同基因型HBV致病能力可能与病毒基因组BCP区A1762T／G1764A突变率的不同有关,而与前C区G1896A突变无关。     

HBV前-C区和BCP区变异与肝细胞癌的相关性分析

目的探讨HBV前-C区G1896A和BCP区A1762T/G1764A变异与肝细胞癌(HCC)的关系及其可能的机制。方法选择于青岛市传染病医院住院的HBV DNA104拷贝/ml的慢性HBV感染者82例,其中慢性乙型肝炎(CHB)29例,乙型肝炎肝硬化(LC)27例,HBV相关肝细胞癌(HCC)26例,采用实时荧光PCR法检测其HBV前-C区1896位变异和BCP区1762/1764位变异,并采用ELISA法检测血清肿瘤坏死因子α(TNF-α)水平。结果 HCC组和LC组前-C区G1896A和BCP区A1762T/G1764A变异率、血清TNF-α水平均显著高于CHB组,但HCC组和LC组间无显著差异。前-C区G1896A和BCP区A1762T/G1764A变异者血清TNF-α水平均显著高于非变异组。结论 HBV前-C区G1896A和BCP区A1762T/G1764A变异与HCC形成有关,机制是否与HBV变异和TNF-α水平间的因果关系相关,有待进一步研究。     

乙型肝炎病毒BCP变异与拉米夫定治疗后HBVDNA反弹关系的研究

目的 探讨HBV BCP变异与拉米夫定抗病毒治疗后HBVDNA反弹的关系.方法 应用PCR-序列分析法,检测拉米夫定治疗(100mg/d)1年以上,达到病毒学应答半年以上,再出现HBV DNA反弹(HBV DNA拷贝数≥1.0×104拷贝/ml)的27例乙型肝炎患者(治疗组),以及19例从未用过抗病毒治疗患者(对照组)的HBV C区基本核心启动子(BCP)的突变位点.结果 1.治疗组HBVDNA反弹的27例BCP(A1762T G1764A)变异检出率44.44%(12/27)高于对照组26.32%(5/19),但无统计学差异,P>0.05.2.4例HBVDNA反弹患者治疗前未检出BCP(A1762T G1764A)变异,治疗后有2例检出BCP(A1762T G1764A)变异.结论 BCP(T1762/A1764)变异可能与拉米夫定治疗后HBVDNA反弹有关.     

家系感染乙型肝炎病毒基因变异与HLA-Ⅱ类等位基因的关系

目的研究家系内慢性乙型肝炎病毒基因变异特征及与HLA-II类分子基因多态性的关系。方法采用PCR扩增和产物测序检测HBV前C区1896位及BCP区1762/1764位变异,分析家系内慢性HBV感染者121例（实验组）病毒变异特征及与非家系慢性乙肝患者83例（对照组）病毒变异频率差异;用PCR/SSP对家系内慢性HBV感染者的HLA-DQA1和DQB1等位基因多态性进行测定;分析HLA-II类分子基因多态性与家系内慢性乙型肝炎病毒基因变异的关系。结果实验组前C区1896位变异、BCP区1762/1764位双变异及联合变异率均高于对照组;HLA-DQA1＊0501和DQB1＊0301等位基因频率和家系慢性HBV感染者前C区1896位、BCP区1762/1764位及联合变异有关;母亲为第一代的感染家系中,子女的前C区1896位及BCP区1762/1764位变异与母亲是否有该位点变异差异无显著性。结论家系感染HBV患者中,HBV前C区1896位、BCP区1762/1764位双突变及联合变异频率明显高于无家系感染的慢性乙型肝炎患者;家系内感染HBV前C区1896位、BCP区1762和1764位变异并非都是由上一代遗传或传播而来,而主要是与个体的免疫状况有关。     

慢性重型乙型肝炎前C区及BCP区基因突变的临床意义

应用基因芯片杂交技术检测慢性重型乙型肝炎（慢重肝）及非重型肝炎（包括慢乙肝及肝硬化）患者血清中HBV前C区A1896、A1899及BCP区T1762/A1764联合突变的发生率,比较慢重肝好转或治愈患者及恶化或死亡患者前C区及BCP区基因突变情况。结果慢重肝前C区A1896、A1899,BCP区T1762/A1764联合突变率及两区多位点突变率与慢乙肝或肝硬化患者比较均有显著统计学差异（P均〈0.01）;慢重肝好转或治愈患者A1896、A1899及多位点变异率与恶化或死亡患者比较均有统计学差异（P均〈0.05）。提示HBV前C区及BCP区基因变异为慢重肝的重要发病机制之一。     

慢性重型乙型肝炎患者HBVDNA前C／BCP区突变基因分析

目的分析慢性重型乙型肝炎（慢重乙肝）患者HBVDNA前C区和基本核心启动子（前C／BCP）区突变特点与意义。方法收集87例慢重乙肝和196例慢性乙型肝炎（慢乙肝）患者血清，提取HBVDNA，用巢式PCR扩增HBVDNA前C／BCP区基因，PCR产物进行DNA测序，用NBI软件比对结果，重点分析G1896、G1862、G1899、A1762、G1764、T17536个位点突变。结果慢重乙肝组和慢乙肝组6个位点突变全阴率分别为3．4％和28．1％（P〈0．01）；慢重乙肝组在其中5个位点上的突变检出率显著高于慢乙肝组。此外，慢重乙肝组和慢乙肝组≥三联突变检出率分别为56．3％和35．2％（P〈0．01），≥四联突变检出率分别为25.3％和8．7％（P〈0．01），插入／缺失突变检出率分别为10．3％和1．0％（P〈0．01）。结论HBVDNA前c／BcP区基因突变发生频率的增加与慢乙肝发生重症化相关，结合临床资料分析突变的意义将有助于认识慢乙肝重症化的发生机制。     

乙型肝炎病毒前核心区及基本核心启动子变异的检测及其对患者疾病谱的影响

目的探讨乙型肝炎病毒(HBV)前核心区(前C区,nt1896)及基本核心启动子(BCP,nt1762/1764)变异在慢性HBV感染者疾病谱的分布及对患者疾病谱的影响。方法416例血清HBsAg阳性、HBVDNA定量大于1.0×104拷贝/毫升的患者,采用微流基因芯片检测HBV前C区及BCP变异。结果416例HBV感染者中302例为HBeAg(-)患者,其中248例(82.12%)有前C区或BCP变异,41.06%为前C区变异,31.12%BCP变异,2种同时变异为9.94%。HBeAg(-)的慢性乙型肝炎和肝硬化患者前C区变异分别为64.72%和83.33%(x2=0.89,P>0.05),均大于HBeAg(-)无症状携带者的28.47%(x2=54.20,P<0.01;x2=5.29,P<0.05);而HBeAg(-)无症状携带者BCP变异达77.19%,大于HBeAg(-)慢性乙型肝炎和肝硬化患者(x2=69.73,P<0.01;x2=10.58,P<0.01)。而在114例HBeAg(+)患者中28.95%有前C区或BCP变异。结论前C区或BCP变异在慢性HBV感染者疾病谱的分布不同,在HBeAg(-)/HBVDNA(+)与HBeAg(+)/HBVDNA(+)患者变异率差异显著。HBV前C区可能是该病变反复及加重的一个重要原因,但BCP变异临床意义不明确。     

孕妇中乙型肝炎病毒前C区和核心启动子区热点变异研究

目的研究乙型肝炎病毒（HBV）携带产妇体内HBV前C区和核心启动子（CP）区热点变异情况。方法82例无症状慢性HBV携带临产孕妇采用HBV核酸扩增荧光定量检测试剂盒抽提孕妇血清HBVDNA,血清HBsAg、HBeAg采用EIA法检测,半巢式PCR法扩增产妇HBV前C区、CP区核苷酸片段,ABI3730型DNA自动荧光测序仪对PCR产物直接测序。结果82例无症状HBV携带临产孕妇中HBsAg单阳性52例,HBsAg、HBeAg双阳性30例;单阳性孕妇中1896G→A变异的检出率为21．2％（11／52）,仅测到1例双阳性孕妇存在1896G→A变异,1899G→A变异仅发生在1例单阳性孕妇,且与1896G→A变异连锁出现。1762A→／1764G→A变异总是连锁出现,且仅发生于单阳性孕妇,单阳性孕妇中双变异的检出率为17．3％（9／52）。结论HBV前C区、CP区1896G→A及1762A→T／1764G→A热点变异在无症状HBV携带单阳性孕妇中有较高的检出率,HBV前C区和核心启动子区的热点变异可能与肝损伤的严重程度无关。     

Precore and core promoter mutations,hepatitis B virus DNA levels and progressive liver injury in chronic hepatitis B

BACKGROUND/AIMS: To elucidate the viral factors responsible for progressive liver injury in chronic hepatitis B. METHODS: We analyzed 179 persistently infected patients (21 asymptomatic carriers, 126 with chronic hepatitis and 32 with cirrhosis) with genotype C hepatitis B virus (HBV). HBeAg/anti-HBe, levels of HBV DNA, mutations in the basic core promoter (BCP) region at nucleotides 1762/1764 and mutation in the precore (preC) region at nucleotide 1896 were determined. Serial samples from 18 patients also were analyzed. RESULTS: HBeAg/anti-HBe and HBV DNA levels per se were not related to liver fibrosis. The frequency of BCP mutations increased with progression of liver fibrosis. Although the preC mutation was detected more often among the LC group, the role of this mutation in progression of fibrosis seems less than that of the BCP mutations. Sequential analysis showed that (1) rapidly progressing cases were positive continuously for double mutations in the BCP with a wild-type precore sequence, and (2) asymptomatic cases with anti-HBe acquired the preC mutation during their clinical course. CONCLUSIONS: Double mutations in the BCP region at nucleotide 1762/1764 are closely related to progression of chronic liver disease. Acquisition of mutation in the preC region at nucleotide 1896 may contribute to inactivation of chronic liver disease.     

HBsAg, HBeAg and HBV DNA level changes and precore/basal core promoter mutations in the natural history of chronic hepatitis B in Indonesian patients

Introduction

Chronic hepatitis B (CHB) is a state of complex interactions between the hepatitis B virus (HBV) and host. We studied the changes in hepatitis B surface antigen (HBsAg), hepatitis B ‘e’ antigen (HBeAg) and HBV DNA levels, considering the implications of HBV genotype, basal core promoter (BCP) A1762T/G1764A and precore G1896A mutations in CHB.

Methods

One hundred fifty-two treatment-naïve CHB patients were classified into immune-tolerant (IT), immune-clearance (IC), low/non-replicative (LR) and ‘e’-negative hepatitis B (ENH) phases, based on HBeAg status, HBV DNA and ALT levels. HBV DNA was detected and quantified by polymerase chain reaction, then analyzed by sequencing. HBsAg and HBeAg levels were measured serologically.

Results

HBsAg and HBV DNA levels varied between CHB phases, with HBsAg highest in IT and lowest in LR, and HBV DNA high in IT and IC, and lowest in LR. Both markers increased in ENH. Correlation between HBsAg and HBV DNA was significant in IT and IC, modest in ENH, but missing in LR. HBeAg and HBV DNA levels were dissociated in HBeAg-positive patients. Genotypes B and C were similarly distributed, with precore mutations higher in HBeAg-negative patients and BCP mutations comparable in all phases. Temporal association between HBeAg seroconversion and an increase of BCP/precore mutations was observed.

Conclusion

HBsAg and HBV DNA levels were high and correlated in early CHB phases and dissociated after HBeAg seroconversion, indicating different controls affecting HBV replication and HBsAg production. Selection of BCP/precore mutants may affect disease course and explain the HBeAg–HBV DNA dissociation, a precaution for clinical application of quantitative HBeAg.     

Incidence and clinical significance of hepatitis B virus precore gene translation initiation mutations in e antigen-negative patients

Hepatitis Be antigen (HBeAg)-negative chronic hepatitis B (CHB) is associated with hepatitis B virus (HBV) variants harbouring changes in the precore region. Most commonly, a G to A point mutation at nucleotide 1896 (m1896) creates a novel translation stop codon that prevents HBeAg production. In the Mediterranean region the m1896 mutation prevails in greater than 98% of HBeAg-negative CHB patients. In this study the prevalence of additional mutations in the precore region was investigated among patients with chronic HBV infection. Precore sequences were determined by sequencing serum HBV DNA amplified by polymerase chain reaction (PCR) with primers flanking the precore/core region. Thirty-one HBeAg-negative and five HBeAg-positive individuals were studied. All HBeAg-negative patients (100%) harboured the m1896 mutation and 20 (64.5%) also had a G to A mutation at nucleotide 1899 (m1899). Additional mutations affecting the translation initiation of the precore gene were found in seven (22.5%) patients, all with active liver disease, five of whom had episodes of HBV reactivation. HBeAg-positive patients had no mutations in these positions and neither did any of the five HBeAg-negative patients with normal levels of liver enzymes, representing the healthy carrier state of HBV infection. Serial sample analysis from one patient revealed that the initiation codon mutation developed following HBeAg seroconversion and the appearance of m1896. During periods of high HBV replication, the ratio of mutant to wild-type ATG was found to increase in parallel with HBV DNA levels. These data show that a significant proportion of HBeAg-negative patients who already harbour the 1896 stop codon mutation may subsequently develop precore translation initiation mutations, which appear to be associated with enhanced HBV replication and severe liver disease.     

Hepatitis B virus genotype and basal core promoter/precore mutations are associated with hepatitis B‐related acute‐on‐chronic liver failure without pre‐existing liver cirrhosis

Summary. The study was undertaken to investigate the features and clinical implications of hepatitis B virus (HBV) genotypes, basal core promoter (BCP) and precore (PC) mutations in hepatitis B‐related acute‐on‐chronic liver failure (HB‐ACLF). Samples from 75 patients with HB‐ACLF and without pre‐existing liver cirrhosis and 328 age‐matched patients with chronic hepatitis B (CHB) were analyzed. HBV genotype and BCP/PC mutations were determined by direct sequencing. Mutations at 8 sites of the BCP/PC region were compared between the two groups of patients. A significantly higher ratio of genotype B to C was found in patients with HB‐ACLF than in patients with CHB (30.7–69.3%vs16.5–82.6%, P < 0.01). Single mutations including T1753V (C/A/G), A1762T, G1764A, G1896A and G1899A and triple mutations T1753V/A1762T/G1764A and A1762T/G1764A/C1766T (or T1768A) were more frequently detected in patients with HB‐ACLF than in patients with CHB. Correspondingly, BCP/PC wild‐type sequences were absent in patients with HB‐ACLF in contrast to 27.1% in patients with CHB. The BCP/PC mutations were found to be associated with increased HBeAg negativity, higher alanine aminotransferase level and lower viral load. Patients with HB‐ACLF infected with the PC mutant virus had a higher mortality. The findings suggest that patients with CHB infected with genotype B with BCP/PC mutations were more likely to develop HB‐ACLF than those with genotype C with wild‐type BCP/PC regions, and patients with HB‐ACLF with the PC mutation had increased risk of a fatal outcome.     

Association of core promoter/precore mutations and viral load in e antigen-negative chronic hepatitis B patients

Apart from core promoter A1762T/G1764A and precore G1896A mutations, other hepatitis B virus (HBV) mutants are detected in hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (CHB). The aim of this study was to determine the effects of those mutants on clinical manifestation and viral loads of genotypes B and C HBV. Seventy-nine HBeAg-negative CHB patients with hepatitis flare were enrolled in this study and their HBV precore/core region were sequenced. Serial biochemical profiles and viral loads were assessed and compared. Fifty-three patients (67%) were infected by genotype B HBV and 26 (33%) were infected by genotype C HBV. The clinical manifestation and HBV viral loads were comparable between the two groups. However, genotype B was significantly associated with precore G1896A mutation (92.5%), and more mutations within nucleotide 1809-1817 were detected in patients infected by genotype B as compared with those infected by genotype C (18.9%vs 3.8%). Most of the cases had mutations at the -2, -3 or -5 position from the precore AUG initiation codon. Triple core promoter mutations T1753C/A1762T/G1764A [corrected] appeared to be linked to genotype C rather than genotype B HBV (19.2%vs 1.9%; P = 0.013). In multivariate analysis, the presence of either triple core promoter 1753/1762/1764 mutation or nucleotide 1809-1817 mutation was the only factor associated with lower HBV viral load (<70 Meq/mL) (odds ratio = 9.01; 95% CI 1.11-71.43; P = 0.04). In conclusion, minor HBV variants with mutations in the core promoter and precore region were detectable in genotypes B and C. Such HBV variants are genotype specific and related to viraemia levels.