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。     

A complete genomic analysis of hepatitis B virus genotypes and mutations in HBeAg-negative chronic hepatitis B in China

Summary.  We aimed to study the distribution of hepatitis B virus (HBV) genotypes/subgenotypes in different parts of China and their clinical impact on the severity of hepatitis B e antigen (HBeAg)-negative chronic hepatitis B. Residual serum samples from a cohort of HBeAg-negative chronic hepatitis B patients in Hong Kong, Shanghai and Beijing were studied. Complete HBV genomic sequencing was performed for phylogenetic tree analysis and determination of HBV mutations was carried out. Mutations associated with severe liver fibrosis (Ishak score 4 or more) were selected by computerized information gain criteria. Genotype B (all subgenotype Ba) HBV was present in 19 of 45 (42%), 12 of 31 (39%) and 5 of 25 (20%) patients in Hong Kong, Shanghai and Beijing, respectively ( P  = 0.16). Ninety-seven per cent of genotype C HBV in Shanghai and Beijing belonged to subgenotype Ce whereas 69% of genotype C patients in Hong Kong belonged to subgenotype Cs ( P  < 0.001). Patients infected by subgenotype Cs had the lowest serum albumin and highest alanine aminotransferase levels compared with subgenotype Ce and Ba. Patients infected by subgenotype Cs also had more severe histological necroinflammation than subgenotype Ce. Two HBV mutations were identified to associate with severe liver fibrosis (G2858C and C2289A) and one mutation was protective against severe liver fibrosis (T2201C). The T2201C mutation was found exclusively among patients (21 of 46 patients, 45%) infected by HBV subgenotype Ce. The clinical differences in HBeAg-negative chronic hepatitis B in China may be influenced by different distribution of subgenotype C HBV.     

Detection of YMDD motif mutations in some lamivudine-untreated asymptomatic hepatitis B virus carriers

BACKGROUND/AIM: It is well documented that long-term lamivudine treatment induces emergence of lamivudine-resistant hepatitis B virus (HBV), namely, YMDD motif mutation in some patients chronically infected with HBV. We previously reported that there were no YMDD mutant viruses in patients with chronic hepatitis B who were not treated with lamivudine. In this series, we examined mutations in the YMDD motif gene in asymptomatic carriers who maintained normal ALT values for 1 year or more. METHODS: Serum samples obtained from 18 patients chronically infected with HBV who consulted our university were used. None of these patients had any experience of using antiviral agents. For detection of mutant viruses, a kit developed in our laboratory was used. RESULTS: Mutations were detected in five of 18 samples: YMDD+YIDD in three samples and YMDD+YVDD+YIDD in two samples. All of these five samples were positive for anit-HBe. In five samples in which mutations were observed, sequencing was carried out following subcloning. CONCLUSION: The present study demonstrates that YMDD mutant viruses are present in lamivudine-untreated asymptomatic hepatitis B virus carriers as well.     

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.     

Relationship between hepatocellular carcinoma and hepatitis B virus genotype with spontaneous YMDD mutations

AIM: To investigate the relationship between hepatitis B virus (HBV) genotype with spontaneous YMDD mu-tations and hepatocellular carcinoma (HCC) in HBV-related cirrhosis. METHODS: We investigated 264 liver cirrhosis pa-tients who were not treated with antiviral drugs, in-cluding 81 patients with HCC. YMDD mutations were detected by fluorescent hybridization bioprobe poly-merase chain reaction (PCR) and melting curve assay using the Diagnosis Kit for HBV YMDD Mutation. Serum HBV genotypes were detected by real-time PCR using genotype-specific TaqMan probes. Statistical analysis was performed according to data type using the t test, χ2 test and unconditional logistic regression analysis. RESULTS: In the HCC group, genotype C strains, spon-taneous YMDD mutations, and genotype C strains with YMDD mutations were detected in 33 (40.74%), 13 (16.05%) and 11 (13.58%) patients, respectively. In the liver cirrhosis (LC) group, HBV genotype C strains,spontaneous YMDD mutations, and genotype C strains with YMDD mutations were detected in 33 (18.03%), 7 (3.83%) and 2 (1.09%) patients, respectively. The dif-ferences in genotype C strains, spontaneous YMDD mu-tations, and genotype C strains with YMDD mutations between the two groups were statistically significant (χ2=15.441, P=0.000; χ2=11.983, P=0.001; P=0.000). In the HCC and LC groups, there were seven patients infected by genotype B strains with YMDD mutations and 13 by genotype C strains with YMDD mutations. Further research revealed that HCC oc-curred in 2 patients infected by genotype B strains with YMDD mutations and 11 infected by genotype C strains with YMDD mutations. The difference was statistically significant (P=0.000). Unconditional logistic regres-sion analysis revealed that patients infected by geno-type C strains with spontaneous YMDD mutations had a 7.775-fold higher risk for the development of HBV-related HCC than patients infected by other type HBV strains (P=0.013, 95%CI: 1.540-39.264). CONCLUSION: Genotype C strains with spontaneous YMDD mutations ar     

YMDD耐药变异与HLA等位基因多态性的相关性

目的：初步探讨慢性乙型肝炎(CHB)患者拉米夫定治疗中YMDD变异与HLA-A,B,DRB1各位点等位基因分布频率的相关性．方法：对142例CHB患者,采用荧光标记杂交双探针PCR融解曲线法(FH-PCR-MC)检测血浆HBV YMDD变异；对其中56例患者的外周血白细胞,采用序列特异性引物/聚合酶链式反应(PCR-SSP)技术检测人类白细胞表面抗原等位基因(HLA-A-B,DRB1)分型．结果：在用拉米夫定治疗的142例CHB患者中,YMDD变异率为56．3％．HLA-B~*58和DRB1~*03等位基因分布频率在YMDD变异组与YMDD野生组比较有显著性降低(0．013 vs 0．094,P=0．036；0．000 vs 0．063,P=0．024)；HLA-A~*30等位基因分布频率在YIDD组明显增高,与YVDD组比较差异显著(0．158 vs 0．024,P=0．034)；HLA-A~*33等位基因分布频率在YVDD变异组明显增高,与YIDD变异组比较差异显著(0．119 vs 0．000,P=0．028)．结论：YMDD耐药变异与HLA等位基因多态性有一定相关性．携有HLA-B~*58和DRB1~*03等位基因的个体感染的HBV可能不易发生YMDD变异；携有HLA-A~*30等位基因的个体感染的HBV可能易发生YIDD变异：携有HLA-A~*33等位基因的个体感染的HBV可能易发生YVDD变异．     

Hepatitis B virus genotypes and hepatitis B surface antigen mutations in family contacts of hepatitis B virus infected patients with occult hepatitis B virus infection

Background:  The association and profile of surface gene mutations with viral genotypes have been studied in patients with chronic hepatitis B virus (HBV) but not in subjects with occult HBV infection.
Aim:  This study aimed to investigate the association of surface gene mutations with viral genotypes in occult HBV infection.
Materials & Methods:  Of 293 family contacts of 90 chronic HBV index patients, 110 consented for the study. Of 110 subjects, 97 were hepatitis B surface antigen (HBsAg) negative. HBV genotyping was done using direct DNA sequencing. The S-gene was also sequenced in 13 chronic hepatitis B patients to serve as controls.
Results:  Twenty-eight (28.8%) of the 97 subjects had occult HBV infection. Bidirectional sequencing of partial S-gene was successful in 13 of them. Seven (53.8%) of the viral sequences are genotype A1, two (15.3%) each having genotypes D5&D2 and one each (7.6%) having D1&G genotypes. Seven (53.8%) of the 13 HBsAg positive patients, had genotype D&6 (46.1%) genotype A. A128V & T143M mutations were observed in 5 of 13 (38.4%) subjects and A128V & P127S in 2 of 13 (15.3%) patients ( P  = 0.385). A128V mutation was seen in two (15.3%) subjects with D2 genotype, while T143M mutation was seen in three (23.07%) subjects with A1genotype. At aa125, three (23.07%) subjects with D5 genotype had methionine instead of threonine. There were wild type sequences in five (38.4%) subjects, one each of D1, G genotypes (20%) and four A1 (80%) genotypes. None of the subjects had G145R mutation.
Conclusions:  Occult HBV infection may be common in household contacts of chronic HBV infected patients. Equal prevalence of A&D sub-genotypes was present in occult HBV subjects and in chronic HBV patients. Mutations of the S-gene are genotype specific in both occult as well as chronic HBV infection.     

乙型肝炎病毒YMDD变异后果及原因分析

目的分析乙型肝炎病毒YMDD变异的原因及后果,探讨YMDD变异后应采取的措施,为变异后临床治疗提供依据。方法对乙型肝炎病毒YMDD变异的79例患者变异前后的临床及实验室资料进行回顾性分析。结果在拉米夫定抗病毒治疗者YMDD变异中,YVDD较YIDD变异多见;无拉米夫定治疗史者与有拉米夫定治疗史者YMDD变异后拉米夫定抗病毒治疗结果有显著性差异;YMDD变异前后肝功能损害有显著性差异;YVDD变异和YIDD变异比较,肝功能损害无显著性差异。结论未使用拉米夫定抗病毒者出现YMDD变异后,拉米夫定治疗有效;拉米夫定抗病毒治疗者,YMDD变异后患者肝功能损害明显;肝功能损害与YMDD变异的亚型无关。     

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.     

慢性HBV感染YMDD自然变异的研究进展

HBV DNA聚合酶(polymerase,P)的变异主要发生在YMDD区域,并与拉米夫定的耐药有关.尽管这些变异株会在应用拉米夫定之后出现,但是他们也会"自然产生".很多学者都已证实了YMDD自然变异株的存在.目前检测YMDD变异的方法有多种,但还没有一个完全统一的方法.HBV YMDD变异可能与HBVDNA水平及其基因型等有一定的关系.     

乙型肝炎病毒基本核心启动子突变与基因型的关系

目的研究乙型肝炎病毒（HBV）基本核心启动子（BCP）突变与HBV基因型的关系。方法随机选取我院68例慢性乙型肝炎患者外周血,采用荧光定量PCR结合TaqmanMGB探针技术检测HBV基因型,并用基因扩增和DNA测序方法检测BCPT1762／A1764双突变。结果68例患者HBV分型中,B基因型20例,C基因型46例,B、C混合型1例,未分型（非B非C型）1例。66例B、C两基因型中,B基因型组T1762／A1764双突变5例,突变率25．0％（5／20）,C基因型组T1762／A1764双突变24例,突变率52．2％（24／46）,C基因型T1762／A1764双突变率明显高于B基因型（P〈0．05）。结论苏州地区慢性乙型肝炎患者基因型以C型和B型为主,C基因型比B基因型更易发生T1762／A1764双突变。     

拉米夫定治疗无良好应答患者乙型肝炎病毒P区突变与基因型的关系

目的 观察拉米夫定治疗后无良好应答的慢性乙型肝炎患者HBV P区变异情况与基因型的关系.方法 对631例拉米夫定治疗后无良好应答的慢性乙型肝炎患者进行研究.通过荧光定量PCR或核酸测序确定HBV基因型,直接测序观察P区突变,实时荧光定量PCR方法检测患者病毒载量,比较不同基因型患者的HBV DNA水平及HBV P区变异情况.计量资料采用成组设计资料t检验,计数资料采用x~2检验或Fisher精确检验.结果 631例慢性乙型肝炎患者中,B基因型HBV感染者272例,C基因型感染者359例,C基因型感染者患者年龄为(39.1±11.4)岁,明显大于B基因型感染患者的(33.7±9.7)岁(t=-6.55,P<0.01).C基因患者病毒载量为(5.96±1.22)log_(10)拷贝/ml,高于B基因型患者的(5.58±1.21)log_(10)拷贝/ml,t=-2.01,P<0.05.A181V/T变异在C基因型的发生率高于B基因型(0.4%比5.3%,χ~2=12.23,P<0.01),M204I/V,L180M、T184A/G/I/S、S202G/I和V173L变异发生率在B、C基因型之间差异无统计学意义(P值均>0.05).M204I在B基因型的发生率为20.6%,高于C基因型的13.9%(χ~2=4.91,P<0.05);M204V和M201Ⅳ变异在B、C基因型中的发生率差异无统计学意义(χ~2值分别为1.70和2.21,P值均>0.05).拉米夫定耐药发生率在B、C基因型间差异无统计学意义(χ~2=0.00,P>0.05).结论 拉米夫定常见耐药位点在B、C基因型之间无明显差异,但是C基因HBV感染患者病毒载量高于B基因型HBV感染患者;M204I变异在B基因型中出现频率高于C基因型,拉米夫定加用或改用阿德福韦酯后可能会使A181V/T变异在C基因型出现的概率高于B基因型;年龄、免疫因素和非常见位点的变异或许是影响拉米夫定疗效的重要因素.     

Hepatitis B virus taxonomy and hepatitis B virus genotypes

Hepatitis B virus (HBV) is a member of the hepadnavirus family. Hepadnaviruses can be found in both mammals (orthohepadnaviruses) and birds (avihepadnaviruses).The genetic variability of HBV is very high. There are eight genotypes of HBV and three clades of HBV isolates from apes that appear to be additional genotypes of HBV. Most genotypes are now divided into subgenotypes with distinct virological and epidemiological properties. In addition, recombination among HBV genotypes increases the variability of HBV. This review summarises current knowledge of the epidemiology of genetic variability in hepadnaviruses and, due to rapid progress in the field,updates several recent reviews on HBV genotypes and subgenotypes.     

Detection of hepatitis B virus genotypes using oligonucleotide chip among hepatitis B virus carriers in Eastern China

AIM： TO determine the genotype distribution of hepatitis B virus （HBV） with a newly oligonucleotide chip assay among the HBV carriers in Eastern China. METHODS： An assay using oligonucleotide chip was developed for detection of HBV genotypes in serum samples from HBV DNA-positive patients in Eastern China. This method is based on the principle of reverse hybridization with Cy5-labeled amplicons hybridizing to type-specific oligonucleotide probes that are immobilized on slides. The results of 80 randomly chosen sera were confirmed by direct sequencing. RESULTS： HBV genotype B, C and mixed genotype were detected in 400 serum samples, accounting for 8.3% （n = 33）, 83.2% （n = 333）, and 8.5% （n = 34）, respectively. The evaluation of the oligonucleotide assay showed 100% concordance with the amplicon phylogenetic analysis except 9 mixed genotype infections undetected by sequencing. CONCLUSION： The study indicates that HBV genotype C and B prevail in the Eastern China. It is suggested that the oligonucleotide chip is a reliable and convenient tool for the detection of HBV genotyping.     

Characteristics of general distribution of hepatitis B virus genotypes in China

BACKGROUND:Based on differences in the virus nucleotide sequence,hepatitis B virus(HBV)genotypes are presently divided into genotypes A-H.The geographic distributions of HBV genotypes differ in countries and regions.To determine the general characteristics of their distributions in the mainland of China,we reviewed articles on HBV genotypes published in China. METHODS:The Wanfang Database and the CNKI Database were searched for original articles involving HBV in China,and then the data from the articles wer...     

我国南北两城市乙型肝炎病毒血清型和基因型的调查研究

用S基因序列测定法对我国南北两城市530例乙型肝炎表面抗原(HBsAg)阳性血清进行乙型肝炎病毒(HBV)血清型和基因型测定,以明确其构成情况并对之进行比较。 1.资料与方法:(1)血清标本:随机采取哈尔滨医科大学附属第二临床医学院门诊及住院HBsAg阳性患者246例和广东省廉江市人民医院门诊及住院HBsAg阳性患者284例。患者均排除了丙型肝炎病毒感染及其它可能导致肝脏病变的疾病。     

未经拉米夫定治疗的乙型肝炎病毒YMDD变异检测

乙型肝炎病毒(HBV)YMDD变异被认为与拉米夫定治疗有关。为证实YMDD变异是由药物所致,还是因为其本身与野生株病毒共存,在药物作用下逐渐成为优势株,对未经治     

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.