乙型肝炎病毒基因型及亚型与YMDD、前C和C基因启动子变异的关系

目的 探讨乙型肝炎病毒(HBV)基因型及亚型与YMDD变异的关系,以及前C基因区终止密码变异(A1896)、基本核心启动子(BCP)区T1762/A1764变异在Ba、C1和C2三种基因亚型中的发生情况.方法 采用聚合酶链反应-限制性片断长度多态性(PCR-RFLP)法对211例服用拉米夫定后发生YMDD耐药变异的患者HBV进行基因型、基因亚型、A1896及T1762/A1764变异检测.结果 211份标本中B基因型占50.7%(1071211),C基因型占49.3%(104/211),与广东地区对照人群HBV基因型分布情况相比无统计学差异(χ2=0.508,P=0.476).进一步亚型分析发现,107份B基因型全部为Ba亚型;C基因型有C1和C2两种亚型,其中C1亚型占64.4%(67/104),C2亚型占35.6%(37/104),与广东地区对照人群C基因亚型分布情况相比也无统计学差异(χ2=0.043,P=0.836).A1896变异在Ba亚型中的分布最高(41/107,38.3%),C2亚型次之(13/39,33.3%),C1亚型最低(9/65,13.8%),变异在不同基因亚型中的分布有统计学差异(χ2=11.839,P=0.03).T1762/A1764变异在C1亚型中的分布最高(34/65,52.3%),C2亚型次之(17/39,43.6%),Ba亚型最低(23/107,21.5%),T1762/A1764变异在不同基因亚型中的分布有统计学差异(χ2=18.384,P＜0.001).结论 HBV基因型及亚型并不影响YMDD变异的发生,但3种基因亚型发生A1896及T1762/A1764变异的模式存在明显不同.     

乙肝病毒C基因启动子变异与乙肝病情的关系

研究乙型肝炎病毒（HBV)C基因启动子（CP）变异与无症状慢性HBV携带者（AsC)肝炎发作及与慢性乙肝病情的关系。．通过PCR及其产物直接测序，检测4例AsC、27例慢性乙肝和3例慢性重型乙肝患者血清的HBV CP序列，并定量测定血清的HBV DNA。（1）CP主要变异为nt1726-1730聚集（1726A→C、1727A →T、1730C→G）和nt1762 1764双变异（1762A→T和1764G→A）。（2）CP聚集变与AsC首次肝炎 急性发作有关。11例中，8例出现CP聚集变异。且1例在AsC状态时无CP变异，肝炎发作时出现CP聚集变异。（3）CP聚集变异合并CP双突变的乙肝患者,表现为重型肝炎或迅速进展为肝硬化，HBV DNA高水平；HBeAg／抗HBe转移。CP聚集变异与AsC肝炎急性发作有关；CP聚集变异 与CP双变异同时存在，使慢性乙肝病情加重。     

乙型肝炎病毒Y(I/V)DD变异与前C及C基因启动子变异生物信息研究

目的 分析HBV反转录酶区(RT)rtM204位点Y(I/V)DD变异与前C及C基因启动子(PC-BCP)变异关系. 方法 应用MEGA4对来自GenBank/EMBL/DDBJ的人类2 849株HBV全基因序列序列重新排列,分析Y(I/V)DD变异与PC-BCP变异及模式相关性. 结果 rtM204(I/V)DD变异株217株(8.0％); PC-BCP变异株1 543株(54.2％),有(1)G1896A、(2)G 1899A、(3) G1896A+G1899A、(4) A1762T/G1764A、(5) A1762T/G1764A+G1896A、(6)A 1762T/G 1764A+G1899A、(7) A1762T/G1764A+G1896A+G1899A 7种变异模式; Y(I/V)DD与PC-BCP联合变异165株.YMDD与PC-BCP双变异率高于单纯YMDD变异率(76％比24.0％,x2=45.283,P=0.000);YIDD与PC-BCP双变异率高于YVDD与PC-BCP双变异率(85％比64.9％,x2=11.836,P=0.000)及使用LAM致YMDD与PC-BCP双变异率高于未使用LAM预存YMDD与PC-BCP双变异率(89.3％比58.9％,x2=27.084,P=0.000).二分类logistic回归分析仅对YIDD有影响而对YVDD无影响的PC-BCP变异模式有G1896A-G1899A(P=0.000,OR=7.573)、A1762T/G1764A-G1899A(P=0.000,OR=6.539)和A1762T/G 1764A-G 1896A-G1899A(P=0.000,OR=6.596). 结论 YMDD变异与PC-BCP变异相关;PC-BCP变异模式的差异与YI/VDD变异选择强度有一定的关系.     

乙型肝炎病毒感染者病毒基因型和亚型分布及其临床意义

目的研究不同类型乙型肝炎病毒（HBV）感染者中HBV基因型和亚型分布情况及其临床意义。方法应用基因型和亚型特异性引物聚合酶链反应法（PCR），对北京、长春、汉川，深圳，清远和南京等6个城市445份HBV感染者血清进行基因型及亚型分型，其中急性肝炎7例，无症状携带者36例，慢性乙型肝炎352例，肝硬化28例，肝细胞癌22例。通过对PCR产物测序确定其基因型，以验证该法的准确性。结果445份血清中，239例（53．7％）为C型，其中13例（5．4％）为C1亚型，135例（56．5％）为C2亚型，91例（38．1％）为非C1／C2亚型；145例（32．6％）B型，其中100例（69．0％）为Ba亚型，25例（17．2％）为Bj亚型，20例（13．8％）为非Ba／Bj亚型；61例（13．7％）为B型与C型混合感染，其中6例（9．8％）为Ba与C1亚型混合感染，3例（4．9％）为Bj与C1亚型混合感染，15例（24．6％）为Ba与C2亚型混合感染，8例（13．1％）为Bj与C2型混合感染，11例（18．0％）为Ba与非C1／C2亚型混合感染，7例（11．5％）为Bj与非C1／C2亚型混合感染，2例（3．3％）为非Ba／Bj亚型与C1亚型混合感染，3例（4．9％）为非Ba／Bj亚型与C2亚型混合感染，6例（9．8％）为非Ba／BJ亚型与非C1／C2亚型混合感染。未检测到其他基因型及亚型。在不同类型乙型肝炎病毒感染者中，B型，C型、B与C型混合感染及亚型分布差异有统计学意义，在肝硬化和肝细胞癌患者中C型所占比例较高（分别为78．6％和86．4％），无症状携带者中B型所占比例较高（72．2％）。但不同性别患者中，HBV基因型和亚型分布无差异。在HBeAg阳性和阴性感染者中，HBV基因型和亚型分布差异也有统计学意义。结论该6个城市HBV感染者中，以B2和C2亚型占优势，C基因型可能与肝硬化和肝细胞癌的发生有关。     

山东地区HBeAg阳性慢性乙型肝炎患者病毒基因型和亚型分布与临床

根据HBV全基因组序列差异≥8%或S基因序列差异≥4%,可将HBV分为A、B、C、D、E、F、G、H 8个基因型。目前已有报道,不同基因型可进一步分为不同的基因亚型。本研究对128例山东地区HBeAg阳性CHB患者HBV基因型、亚型及其临床意义进行了初步探讨。     

HBV S基因亚型与前C基因1896位点变异关系的初步研究

目的:研究HBV S基因亚型与前C基因1896位点变异的关系。方法:对104例病人血清用PCR技术特异性扩增前C基因1896位点突变和用PCR-RFLP技术对HBV S基因分型。结果:①1896位点变异检出率为63.46％;②武汉地区HBVS基因亚型Ⅰ感染率为68.27％,亚型Ⅱ为25.00％,亚型Ⅲ为4.81％,亚型Ⅰ Ⅱ复合感染为1.92％;③在亚型Ⅱ中,单纯野生株感染为80.77％,单纯变异株为7.7％,野生株变异株同时感染为11.54％,而占感染多数的亚型Ⅰ中,野生株和变异株的感染无差异。结论:1896位点是高频率变异位点,其变异不是随机的,而是与HBV不同的S基因亚型有关,基因亚型Ⅱ不易发生1896位点变异,受感染的机体内环境只是起促进变异的作用。     

十堰地区乙肝病毒基因型分布及其临床意义

目的:了解十堰地区乙肝病毒基因型分布情况以及基因型与临床特征的关系,探讨其临床意义。方法:采用型特异性引物巢式PCR方法对本地区244例乙型肝炎患者进行基因型检测,同时对部分PCR产物进行测序,确定其基因型。结果:在244例乙型肝炎患者中,B型165例(67.62%)、BC混合型74例(30.33%)、C型5例(2.05%),未发现A、D、E、F型;AsC中,B型36例,占76.60%;HF、AHB、HCC中B基因型占绝对优势,分别为95.96%、100%、81.82%,显著高于LC的57.69%和CHB的60.00%,其中HF与LC、CHB之间差异显著(P<0.05,P<0.01);CHB中BC混合型51例(37.38%),与AsC中10例(21.28%)比较有统计学意义(P<0.05);B基因型患者血清ALT(323.57±596.83IU/L)、AST(254.88±460.94IU/L)、TBil(100.67±137.09μmol/L)均高于BC混合型(160.70±235.62IU/L、137.57±201.95IU/L、50.97±78.93μmol/L),差异有显著性意义(P<0.05);基因型分布在年龄、性别及HBeAg阳性率上均无差异;B基因型HBV DNA水平处于高度复制状态(>108copies/ml)的比例占49.12%(56/114),比BC混合型32.14%(18/56)高,BC混合型中中度复制(105~108copies/ml)和低度复制(<105copies/ml)占67.86%(38/56),比B型50.88%(58/114)高(P<0.05)。结论:本地区基因型以B型为主,BC混合型次之,C型少见;B型在AsC、HF、AHB、HCC中占优势,与疾病的活动度及预后密切相关;BC混合型在CHB和LC中多见,与乙型肝炎慢性化相关。     

感染两种HBV C基因亚型患者病毒变异特点比较

目的调查乙型肝炎病毒C1和C2亚型感染者的临床、病理和前C基因区的变异特点。方法运用聚合酶链反应-限制性片段长度多态性法，并结合HBV前C／C区序列测定，对广东地区63例慢性乙型肝炎患者C基因亚型和前C区变异特点进行分析，并对两种基因亚型感染者的多项临床和病理检测指标进行比较。结果所选C1和C2亚型感染者的年龄和性别构成无差异，其肝功能指标、HBV DNA水平以及肝组织炎症活动度和纤维化分期评分也无显著性差异。在前C基因区变异方面，C1亚型毒株发生C基因核心启动子变异机率高于C2亚型，C2亚型毒株发生前C终止密码变异的机率显著高于C1亚型，但两种变异的总发生率在两种亚型间并无显著性差别。结论两种C基因亚型的临床致病性并无明显差异，但在形成HBeAg阴性HBV感染方面两种毒株会采取不同的变异模式。     

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.     

HBeAg阳性慢性乙型肝炎初治患者BCP区A1762T/G1764A变异株定量检测结果分析

目的探讨HBeAg阳性慢性乙型肝炎初治患者BCP区A1762T/G1764A变异株定量检测的临床意义。方法通过单标记探针联合选择性阻断实时荧光定量PCR法精确定量检测97例HBV DNA阳性慢性乙型肝炎初治患者BCP区A1762T/G1764A变异株,并进行统计学分析。结果 97例HBeAg阳性患者变异株的含量会随着HBV DNA水平的升高而降低(P0.01)。变异株含量同时与HBeAg水平呈显著相关,随着HBeAg水平的升高,变异株含量降低(P0.01)。结论对HBV感染者的BCP区A1762T/G1764A变异株进行定量检测,可对患者病情的可能发展进行预测,从而可以采取有效的防治措施。     

Hepatitis B virus genotypes and subgenotypes in China

Eight Hepatitis B virus (HBV) genotypes (A to H) have been identified based on an intergenotype divergence of 8% or more in the entire nucleotide sequence. Subgenotypes have also been identified in different HBV genotypes. As a highly endemic area for HBV infection, the prevalence of chronic HBV infection in China is between 8 and 20% of the general population. Genotypes B and C were identified as the most common HBV strains and account for approximately 95% of Chinese patients. Further study confirmed all genotype B strains belong to subgenotype Ba. Two of genotype C subgenotypes, C1 (Cs) and C2 (Ce), were found in China and they showed different geographic distributions. Genotype A was very rarely found, while genotypes E, F, G and H have not beenreported until now. Two types of HBV C/Drecombinant viruses have been identified in west China and distinct geographic and ethnic distributions were observed. Significant differences were observed ( P  < 0.001) in the prevalence of A1896 and T1762/A1764 mutations among HBV Ba, C1 and C2 subgenotypes in Chinese patients. Accumulating evidence showed the response rate to antiviral therapy in Chinese patients is higher in genotype B than genotype C patients on interferon treatment, but no difference was observed on nucleoside/nucleotide analog treatment.     

Hepatitis B virus genotypes, subgenotypes, precore, and basal core promoter mutations in the two largest provinces of Pakistan

Background and Aim:  Hepatitis B virus (HBV) genotyping has been done in most countries, but unfortunately, in Pakistan, HBV genotypic distribution is still unclear. The aim of the present study was to determine the prevalent genotype and subgenotype in the two most populated provinces in Pakistan: Punjab and Sind.
Methods:  In total, 236 HBV DNA-positive samples were selected for genotyping by polymerase chain reaction–restriction fragment length polymorphism (RFLP). The RFLP results were further confirmed with whole genome and partial genome sequencing.
Results:  Genotype D was detected as the most prevalent (93.22%) genotype in all eight cities of both provinces; genotype C was present in 5.93% and genotype A was present in 0.85% of the samples. The D1 subtype was present in 84%, and D2 was present in 8% of 25 whole genome-sequenced samples. The C2 subtype was detected in 58.33% of S gene-sequenced samples, while D1 was detected in the remaining 41.67% of 24 samples sequenced for the S gene. Subtype D1 is the most dominant in D, while C2 is dominant in genotype C. Eight- and 15-bp deletion mutations were also detected in genotype D samples. Other precore and basal core promoter (BCP) mutations included T1915 (100%), A1679 (86.96%), T1762 (39.13%), and A1764 (30.43%), which were also detected in the genotype D samples.
Conclusion:  Genotype D subtype D1 is the most prevalent HBV strain in Pakistan with 8-bp deletion mutants the most common in HBV carriers.     

Hepatitis B virus genotypes in Europe

There are eight genotypes of hepatitis B virus (HBV). Most genotypes can be further divided into subgenotypes. HBV genotypes influence the course of disease and treatment, and show geographic preferences. In Europe, A and D are the main genotypes found. Genotype A is more prevalent in northern Europe, where genotype D is mainly found in countries surrounding the Mediterranean Sea and in Eastern Europe. Subgenotype A2 is the dominant subgenotype in Europe, but the geographic prevalence of the four subgenotypes found in genotype D is not yet clear. On treatment with interferon HBV, genotype A, compared to genotype D, showsbetter virological response and in a large proportion of patients, even development of anti-HBs. However, in the first year of treatment with lamivudine, higher rates of emergence of YMDD variants are observed in genotype A. This work summarizes the current knowledge on HBV genotypes in countries with low and intermediate HBV carriership from Europe.     

Identification of hepatitis B virus A1762T/G1764A double mutant strain in patients in Southern Brazil

Infection by hepatitis B virus (HBV) is a worldwide public health problem. Chronic HBV infection with high viral replication may lead to cirrhosis and/or hepatocellular carcinoma. Mutant HBV strains, such as the HBV A1762T/G1764A double mutant, have been associated with poor prognosis and higher risk of the patient for developing cirrhosis and/or hepatocellular carcinoma. This study analyzed the presence of the HBV A1762T/G1764A double mutant in patients with chronic HBV and its association with clinical parameters such as viral load, aminotransferases, and HBV antigens. A total of 49 patients with chronic hepatitis B were included in the study, and the HBV A1762T/G1764A double mutant strain was detected in four samples (8.16%) by polymerase chain reaction followed by restriction fragment length analysis (PCR-RFLP). The viral load was not significantly different between patients with or without the double mutant strain (p = 0.43). On the other hand, carriers of the HBV A1762T/G1764A double mutant had higher levels of ALT (p = 0.0028), while AST levels did not differ between groups (p = 0.051). In this study, 75% of the samples with the HBV A1762T/G1764A double mutation were HBeAg negative and anti-HBe positive, reflecting seroconversion even though they still displayed high viral loads. Our study has shown that the HBV A1762T/G1764A double mutant strain circulates in Brazilian patients, and is associated with elevated levels of ALT and HBeAg seroconversion.     

泉州地区慢性乙型肝炎患者HBV基因型、基因亚型及血清型分布调查

目的调查泉州地区慢性乙型肝炎患者HBV基因型、基因亚型及血清型的分布。方法采用巢式PCR法对48例样本S基因扩增后进行测序,应用Neighbor Joining构建系统进化树并分析其基因型和基因亚型,应用Magnius和Norder法进行血清型分析。结果48例慢性乙型肝炎患者中,检测出B基因型35例（68.8%）,C型13例（31.2%）;B基因型中Ba亚型占97.0%,adw2血清型占93.9%;C基因型中C2亚型占93.3%,adrq+血清型占80.0%。结论泉州地区慢性乙型肝炎患者以B基因型为主,其次是C基因型;B基因型样本中,以Ba亚型和adw2血清型为主,C基因型样本中,以C2亚型和adrq+血清型为主。     

Distribution of hepatitis B virus genotypes： Phylogenetic analysis and virological characteristics of Genotype C circulating among HBV carriers in Kolkata, Eastern India

INTRODUCTION Hepatitis B virus (HBV) belongs to the Hepadnaviridae family of enveloped viruses with double-stranded DNA genome of nearly 3200 bp lengths. The HBV genome consists of four major overlapping open reading frames named surface (S), core (C), po…     

乙型肝炎病毒基因型对乙型肝炎病毒变异的影响

目的探讨乙型肝炎病毒(HBV)基因型对病毒前核心区(前C区,nt1896)及基本核心启动子(BCP,nt1762/1764)变异的影响.方法416例血清HBsAg阳性、HBV DNA定量大于1.0×104拷贝/ml的患者,采用微流基因芯片检测HBV基因型、前C区及BCP变异.结果416例HBV感染者中406例有基因分型结果:B型20.9%、C型65.9%、BC混合型10.8%,10例患者未分出基因型.302例为HBeAg(-)且HBV DNA( )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?P变异,2种同时变异为9.94%.B型患者前C区变异率为22.9%(20/87),与C型患者前C区变异率39.4%(108/274)及B、C混合型变异率40.0%相比均有显著差异(P＜0.01).在BCP变异及双变异,C型患者变异率均大于B型患者,但差异无统计学意义(P＞0.05).B、C混合型患者前C区及BCP变异率与C型相似.结论HBV基因型可影响病毒前C区及BCP变异,以C型为著.     

微流芯片检测HBV前C区nt1896/BCP区nt1762基因突变的临床意义

目的探讨HBV前C区nt1896/BCPnt1762基因突变的临床意义。方法在418例血清HBeAg阴性/抗-HBe阳性的慢性乙型肝炎患者,采用微流基因芯片检测HBV前C区nt1896/BCPnt1762基因突变。同时观察血清ALT患者、HBV DNA水平和临床表现。结果nt1896变异195例(46.7%),1762变异192例(45.9%),ALT>正常上限值198例(47.4%),HBV DNA>1×105copiel/ml150例(35.8%),乏力,纳差,肝区胀痛213例(50.9%)。结论HBV前C区nt1896/BCP1762基因突变与HBeAg阴性患者ALT异常,HBV DNA升高及其临床表现具有相关性。