135例乙型肝炎病毒感染者基因分型及其临床分布

目的研究乙型肝炎病毒（HBV）感染者中HBV基因分型及其临床分布情况。方法应用基因型和亚型特异性引物聚合酶链反应（PCR）法，对鲁西地区135例HBV感染者血清进行HBV基因型及亚型分型。结果未分型11例，已分型124例。其中C型111例（C2基因亚型87例、非C1／C2亚型24例）；B型11例，其中Ba型8例、Bj型3例；B／C混合型2例均为BaC2亚型混和感染。在肝硬化和重度慢性乙型肝炎中C型所占比例较高，分别为100％、88％；无症状携带者中B型所占比例较高为8．51％；HBV基因型分型与性别无关。结论鲁西地区HBV感染者以C基因型为主，其中C2亚型占优势。     

慢性乙型肝炎患者HBV基因型和哑型分布调查

目的研究慢性乙型肝炎患者HBV基因型和亚型流行情况。方法应用HBV基因型和亚型特异性引物PCR法对北京、长春、大连、西安、石家庄、郑州和合肥7个城市660份HBV DNA阳性慢性乙型肝炎患者血清进行基因型和亚型分析。结果在660份HBV DNA阳性血清中,B基因型、C基因型和B／C混合感染分别为16．67％（110／660）、74．54％（492／660）和8．79％（58／660）;在C基因型中,C1亚型6例（1．22％）、C2亚型473例（96．14％）、C1／C2混合基因亚型13例（2．64％）;B基因型均为Ba亚型,B基因型和C基因型混合感染者均为Ba与C2亚型混合感染,未发现其他基因型和基因亚型;不同基因型感染患者HBeAg阳性率差异无统计学意义（P=0．153）;B基因型和C基因型患者之间血清HBV DNA水平差异无统计学意义（6．37±1．62lg copies／ml对6．29±1．76lg copies／ml）,但均高于B和C基因型混合感染患者（5．25±1．65lg copies／ml）。结论这7个城市慢性乙型肝炎患者以B基因型和C基因型感染为主,有部分B／C基因型混合感染。HBV亚型以Ba和C2亚型占优势。     

中国广东地区乙型肝炎病毒基因亚型的分布

目的调查中国广东地区乙型肝炎病毒(HBV)基因型,主要是基因亚型的分布情况.方法应用聚合酶链反应-限制性片段长度多态性法以及序列测定法,对广东地区417例慢性HBV感染者血清进行研究.结果广东地区流行的HBV基因型主要为B型和C型,其中B型为Ba亚型,未发现Bj亚型的存在.C亚型有C1和C2两个亚型,其中C1占63%,C2占37%.结论广东地区流行的HBV基因型以Ba和C1亚型为主,C2亚型较少,Bj亚型极为罕见.     

云南大理白族人群乙型肝炎病毒基因型和亚型的分布

目的调查云南大理地区白族人群乙型肝炎病毒（hepatitis B virus，HBV）基因型和亚型分布情况。方法在大理地区选择100例白族慢性HBV感染者，采用基因型特异性引物分型法和聚合酶链反应-限制性片段长度多态性（PCR—RFLP）方法测定HBV感染者血清HBV基因型和亚型，并用ELISA法测定HBV血清标志物。结果100例HBV感染者中，B型41例（41％），全部为Ba亚型，未发现Bj亚型；C型25例（25％），其中Cs亚型21例（84％），Ce亚型3例（12％），未分型1例（4％）；B＋C混合型34例（34％）。B型感染者与C型感染者比较血清HBeAg阳性率差异有统计学意义（P=0．024）。结论云南大理白族人群HBV感染的基因型主要为B型、B＋C混合型和c型，以Ba和cs亚型为主要流行株，B＋C混合型感染占很大比例。     

厦门市乙型肝炎病毒亚基因型分布的初步研究

目的探讨厦门地区乙型肝炎患者血清乙型肝炎病毒（HBV）基因型的分布情况。方法应用混合性型特异性引物聚合酶链反应法结合琼脂糖电泳，根据PCR产物片段大小直接判定HBV基因型；应用PCR扩增全S基因序列-DNA测序-生物信息学分析方法确定部分样本的亚基因型，并探讨前前S区编码的流行情况。结果在217例可以通过混合性型特异性引物聚合酶链反应法确定基因型的感染者中，B型83例（38．2％）、C型71例（32．7％），B／C混合型63例（29．0％）。HBeAg阳性患者中感染B基因型占50％，B／C型混合感染占22％；抗-HBe阳性患者中B／C型混合感染36％，B型38％；在慢性乙型肝炎患者中，以B基因型多见（46％），在肝硬化和肝癌患者中，以C（41％和42％）或B／C混合基因型（38％和33％）感染为主；20例患者血清经过DNA测序-生物信息学分析方法确定了亚基因型，其中B2亚型2例，C2亚型18例，其中混合性型特异性引物聚合酶链反应判断为B型的4例经过测序分析为C2亚型。B2亚型不编码前前S区，18例C2亚型均编码前前S区。结论本研究提示厦门地区乙型肝炎患者群的HBV基因型B、C型的感染率大致相同，亚基因型分析提示C2亚基因型占90％，可能是B／C基因型重组的结果。C2亚基因型病毒株均编码前前S区，提示前前S区的编码可能具有亚基因型特异性。     

贵州地区慢性乙型肝炎病毒感染者病毒基因亚型研究

目的调查贵州省B、C基因型慢性HBV感染者的病毒基因亚型。方法PCR扩增HBV P区长309 bp的基因片段,扩增产物分别经限制性内切酶NciⅠ、VspⅠ、BstEⅡ酶切,琼脂糖凝胶电泳,根据酶切图谱多态性,用限制性片段长度多态性分析（PCR-RFLP）检测HBV C基因亚型。直接测序确定B基因亚型、对178例用S基因限制性片段长度多态性鉴定为B、C基因型的不同临床类型慢性HBV感染者进行亚型分析。结果84例C基因型HBV感染者中,27例（32.14%）为C1亚型、56例（66.67%）为C2亚型,1例为C1、C2亚型混合感染。94例B基因型HBV感染者中,93例（98.94%）为Ba、1例为Bj亚型感染。从无症状乙型肝炎表面抗原携带者、CHB到肝硬化/肝癌,C1亚型在各组中的比例逐渐降低,分别为60.00%、30.65%和16.67%;而C2亚型在各对应组中的分布逐渐增高,分别为40.00%、67.74%和83.33%。结论贵州地区B、C基因型慢性HBV感染者中,以Ba、C2亚型为主。C1、C2亚型在疾病中的分布有一定差异。PCR-RFLP分析HBV C1、C2亚型,方法简便、特异性强,适合较大样本分析,可用于流行病学调查。     

乙型肝炎病毒基因亚型研究进展

近年来,各国学者对乙型肝炎病毒（HBV）基因型及其亚型的研究十分关注。HBV基因型不仅能反映核酸变异程度和病毒种系发生关系,而且与感染者的临床表现、预后及疗效有关。目前,根据HBV全基因组序列差异≥8％,或S基因序列≥4％,将HBV分为A、B、C、D、E、F、G、H等8个基因型,但基因型H是否是独立于F的一个新基因型,还有待进一步证实。各基因型之间还存在混合感染,如B与C、C与D混合感染等∞。有人认为,混合感染可能与重叠感染或基因型之间的同源重组或部分转换有关。值得注意的是：近年来,除研究HBV基因型外,对HBV基因亚型也进行了深入研究,发现A基因型可进一步分为Aa和Ae亚型0;B型可分为B1（Bi）、B2（Ba）、B3和B4亚型N;C型可分为c1、c2、c3和c4亚型;D型可分为D1、D2、D3和D4亚型,F型可分为F1和F2亚型等（见表1）。     

HBV基因型的流行病学和病毒学特征及与临床的关系（上）

自1988年Okamoto发现HBV可分为不同基因型后，有许多学相继进行了这方面的研究。2003年日本学Sugauchi发现B基因型和C基因型之间还可能发生重组，依是否与C基因型重组分为HBVB基因型j亚型（HBV／Bj）和HBVB基因型a亚型（HBV／Ba）；2004年Sugauchi又对HBVA基因型（HBV／A）进行分析，发现HBV／A可分为e亚型（HBV／Ae）和a亚型（HBv／Aa）。现就HBV基因型的流行病学和病毒学特征及与临床的关系综述如下。     

乙型肝炎病毒B基因型亚型的检测

目的:建立乙型肝炎病毒(hepatitis B virus,HBV)B基因型亚型的检测方法,并对其进行临床研究.方法:根据GenBank中20株Ba亚型,10株Bi亚型以及25株C型全长基因组序列设计Ba、Bj亚型特异探针以及巢式PCR引物.采用反向杂交技术将B亚型特异探针固定在芯片上,通过与地高辛标记的扩增产物杂交检测B型HBV亚型.对镇江地区200例B基因型HBV血清样本进行亚型分析并对患者HBVDNA YMDD变异进行检测.通过对部分血清中的HBV DNA进行序列分析验证该方法的准确性.结果:200例B基因型HBV患者中,Ba亚型184例(92%),Bj亚型16例(8%).在持续使用拉米呋啶的80例患者中,Bj亚型6(0%)例,均无YMDD变异,Ba亚型74例,YMDD变异21(28.4%)例.结论:镇江地区B基因型HBV以Ba亚型为主.Ba、Bj亚型在服用拉米呋啶1年后发生YMDD变异的几率并无统计学上的显著差异.     

HBV亚基因型的临床相关性研究

科学家已经定义了8种HBV基因型和多种亚型，并且显示出它们有特征性的地理分布。基因型A已经被分为Aa／A1（亚洲／非洲型），基因型B分为Bj／B1（日本型）和Ba／B2（亚洲型）。累积的证据证明HBV基因型由于影响病毒复制率和前C区突变频率从而影响HBeAg表达方面具有临床的相关性。[第一段]     

Virological differences between patients infected with subtypes Ba and Bj of hepatitis B virus genotype B

BACKGROUND: Hepatitis B virus (HBV) genotype B is classified into subtype Ba with the recombination with genotype C in the precore region plus core gene and subtype Bj without recombination. Virological and clinical differences between infections with subtypes Ba and Bj, however, are yet to be determined. METHODS: During 1976 through 2001, 224 patients visited Toranomon Hospital in Tokyo, Japan who were infected with HBV genotype B. Subtypes of genotype B were determined by sequencing HBV-DNA recovered from sera for detecting recombination with genotype C. RESULTS: Subtype Ba was detected in 53 patients (24%) and Bj in 167 (75%); subtypes were not able to be determined in the remaining four (1%). The only virological difference was that detection of hepatitis B e antigen at the presentation was more frequent in the patients infected with subtype Ba than those with Bj (63% vs 33%, P = 0.016). There were no differences in the distribution of liver disease of various forms between the patients infected with subtypes Ba and Bj at presentation. No differences were noted, either, in the development of liver cirrhosis or hepatocellular carcinoma, or the loss of hepatitis B surface antigen from serum, between the patients infected with subtypes Ba and Bj during follow up of up to 26 years. CONCLUSIONS: Although there were some virological differences between the patients infected with subtypes Ba and Bj of HBV genotype B, they do not seem to influence the long-term clinical outcome.     

原发性肝癌患者乙型肝炎病毒基因型与突变的地区性差异分析

目的 研究原发性肝癌患者乙型肝炎病毒(HBV)基因型、亚型和突变的地区性差异.方法 HBV阳性的原发性肝癌组织标本80例,其中广西地区20例,上海、浙江、江苏(长三角地区)60例.应用聚合酶链反应(PCR)扩增患者携带的HBV DNA序列,PCR产物直接纯化测序.用NCBI在线的软件viral genotyping tool确定HBV基因型,MEGA(Molecular Evolutionary Genetics Analysis,version 3.1)软件构建系统进化树和进行亚型分型及突变分析.结果 80例肝癌标本中,17例为B基因型(21.3%),57例为C基因型(71.3%),6例为B、C基因型混合感染(7.5%).对17例B基因型和57例C基因型的亚型分型,其中B基因型的亚型全部为B2型,C基因型的亚型有C1、C2、C5等三型,其中有12例为C1型(21.1%),44例为C2型(77.2%),1例为C5型(1.8%).广西地区的C1亚型35%(7/20)明显高于长三角地区的C1亚型8.5%(5/60),而广西地区的C2亚型20%(4120)明显低于长三角地区的C2亚型66.7%(40160).两地区HBV基因亚型分布在统计学上有显著差异.比较两地区的HBV序列还发现,广西地区B基因型CP区T1762/A1764呈现更高的突变性,有6例(100%)存在突变,而长三角地区只有2例(16.7%).结论 两地区原发性肝癌患者的HBV亚型分布和基因型B的CP区T1762/A1764突变率有显著差异.     

新疆维吾尔族慢性乙型肝炎病毒感染者病毒基因型及亚型分布特点

目的 了解新疆维吾尔自治区(简称新疆)维吾尔族慢性HBV感染者基因型、基因亚型分布情况及其与预后的关系.方法 采用聚合酶链反应限制性片段长度多态性分析方法,分析109例新疆维吾尔族慢性HBV感染者感染病毒的基因型及基因亚型.多标本均数比较采用单向方差分析.结果 109例新疆维吾尔族慢性HBV感染者,其中慢性乙型肝炎88例,乙型肝炎肝硬化17例,肝癌4例.13基因型HBV感染者9例,占8.3%,C基因型感染者50例,占45.9%,C/D基因型重组体32例,占29.4%,D基因型感染者18例,占16.5%,C基因型、C/D基因型重组体为主要基因型.经过聚合酶链反应限制性片段长度多态性分析及测序检测,鉴定9份B基因型HBV,均为Ba亚型.50例C基因型HBV感染者病毒基因亚型分布情况:Cl亚型27例,占54%,C2亚型23例,Cl亚型比C2亚型感染者多.在慢性乙型肝炎、乙型肝炎肝硬化、肝癌患者中,HBV Ba基因亚型感染者分别为8例(9.1%)、1例(5.8%)和0例;C2基因亚型感染者分别为17例(19.3%)、8例(47.5%)和2例(50%);C/D基因型感染者分别为29例(33.0%)、2例(11.9%)和1例(25%),随着病情加重,Ba基因亚型和C/D基因型感染者所占比例呈下降趋势,C2基因亚型感染者所占比例增加.结论 新疆地区维吾尔族慢性HBV感染者以Cl基因亚型为主,新疆维吾尔族慢性HBV感染者存在C/D基因型重组体.C2基因亚型HBV感染预示病情严重,预后差.     

A case-control study of response to lamivudine therapy for 2 years in Japanese and Chinese patients chronically infected with hepatitis B virus of genotypes Bj, Ba and C.

BACKGROUND/AIMS: In eastern Asian countries, hepatitis B virus (HBV) genotype Ba (HBV/Ba), HBV/Bj and HBV/C are prevalent. The aim was to investigate the response or resistance to lamivudine therapy among patients with different HBV genotypes. METHODS: Of 67 Japanese and Chinese patients with chronic hepatitis B, 18 patients with HBV/Bj, 15 with HBV/Ba and 34 with HBV/C were selected for a case-control study matched according to gender and age. All the patients were treated with lamivudine for 2 years and evaluated the response or emergence of the YMDD mutation at year 2 during the treatment. HBV genotypes were detected by the restriction fragment length polymorphism. The YMDD mutation was detected by the direct sequencing after amplification by PCR. RESULTS: At year 2 during therapy, 44.8% of the patients showed normalization of ALT and undetectable HBV DNA (favorable response), 35.8% developed the YMDD mutation. There was no significant difference of response to the therapy among the three genotype groups. The emergence of the YMDD mutation was associated with HBV/C. By the multiple logistic regression analysis, however, the significant factor of a favorable response was a higher pretreatment ALT level and negative HBeAg status and the significant factor of the emergence of the YMDD mutation was HBV/C. CONCLUSIONS: Higher pretreatment ALT level, HBeAg status or HBV genotype may affect the response or resistance to lamivudine therapy.     

Epidemiologic and virologic characteristics of hepatitis B virus genotype B having the recombination with genotype C

BACKGROUND & AIMS: Hepatitis B virus (HBV) isolates of genotype B (HBV/B) with or without the recombination with genotype C over the precore region plus core gene have been reported. METHODS: All the 41 HBV/B isolates having the recombination with genotype C (HBV/Ba) possessed the nucleotide 1838 of A in contrast to that of G in all 29 of those without the recombination (HBV/Bj). Taking advantage of this single nucleotide polymorphism, a restriction fragment length polymorphism method was developed that distinguished HBV/Ba from HBV/Bj. RESULTS: HBV/Bj was detected in 90 of the 97 (93%) carriers of HBV/B from Japan, whereas HBV/Ba occurred in all 177 carriers of HBV/B from other countries (China, 20; Hong Kong, 45; Taiwan, 32; Thailand, 30; Vietnam, 30; and the United States, 20 [all of an Asian ethnicity]). In a case-control study, hepatitis B e antigen (HBeAg) and the double mutation in the core promoter (T1762/A1764) were significantly more frequent in 80 carriers each of HBV/Ba than HBV/Bj (35% vs. 18%, P < 0.05 and 33% vs. 15%, P < 0.05, respectively). Differences in the prevalence of HBeAg were more conspicuous between the carriers of HBV/Bj and HBV/Ba older than 30 years (5 of 66 or 8% vs. 16 of 62 or 26%, P < 0.01). CONCLUSIONS: HBV/B having the recombination with genotype C is frequent in Asia, except in Japan, and HBeAg is more prevalent in carriers of HBV/Ba than HBV/Bj.     

慢性乙型肝炎病毒基因型和亚型分布及与临床关系的探讨

目的了解乙型肝炎病毒(HBV)基因型和亚型分布情况,探讨其与临床的关系。方法采用聚合酶链反应-限制性片段长度多态性分析(PCR-RFLP)对2006年1月至4月邯郸市传染病医院收集的108份HBV感染者的血清进行乙型肝炎病毒基因型和亚型分型,分析乙型肝炎病毒基因型与患者临床特点的相关性。结果108例慢性乙型肝炎患者感染的HBV主要以C基因型为主,占93.5%,B基因型占6.5%;B基因型中均为Ba型,C基因型中C2亚型为主,占C基因型的88.1%。不同性别感染基因型和C1、C2亚型分布差异无显著性意义。肝生化指标丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)、总胆红素(TBil)比较提示C基因型患者的肝脏炎症较B基因型患者重,但差异无显著性意义。C基因型患者血清乙型肝炎病毒e抗原(HBeAg)阳性率显著高于B基因型患者。C基因型患者血清HBV-DNA略高于B基因型,但差异无显著性意义。C1、C2亚型间在肝功能、HBeAg阳性率和血清HBV-DNA载量方面差异均无显著性意义。结论慢性乙型肝炎患者感染的HBV主要以C基因型(C2亚型)为主。C基因型的患者血清HBeAg阳性率高于B基因型,C基因型患者与B基因型相比肝脏炎症程度、HBV-DNA载量差异无显著性意义。C1和C2亚型患者的临床特点相似。     

乙型肝炎病毒基因型与病情轻重的关系

目的研究乙型肝炎病毒(HBV)基因型与肝脏损伤程度的相关性。方法随机选取87例慢性无症状乙型肝炎表面抗原携带者(ASC)、157例慢性乙型肝炎(CHB)、22例肝硬化(LC)和18例肝细胞癌(HCC)患者外周血测定HBV S基因序列以明确其基因型。结果基因型以B型和C型为主,分别为26.1％和73.2％。在B型与C型中,ASC、CHB、LC和HCC的构成比差异有非常显著性(X2=15.09,P<0.001),C型与B型相比,C型发展致CHB和HCC所占百分比显著高于B型,分别为59.6％比43.2％,X2=10.87,P<0.001;和7.7％比1.4％,X2=7.41,P<0.001。而LC所占百分比差异无显著性。结论基因型C型与B型相比,C型HBV感染易引起较重肝脏损伤。     

Genotype B hepatitis B virus is associated with severe icteric flare-up of chronic hepatitis B virus infection in Hong Kong

OBJECTIVE: We aimed to investigate the association of viral genotype and the development of icteric flare-up (IF) in chronic hepatitis B virus (HBV) infection. METHODS: Twenty-one consecutive patients suffering from IF of chronic HBV infection, defined as elevation of ALT over five times the upper limit of normal, together with either bilirubin > 50 IU/L or elevated bilirubin plus PT > 3 s prolonged, were studied. Patients from three stages of HBV-related chronic liver disease were studied as controls: 1) asymptomatic carriers (31 patients), defined as persistent normal ALT for at least 2 yr; 2) active early cirrhosis (49 patients), defined as Child's A liver cirrhosis plus HBV DNA > 106 Eq/ml; and 3) decompensated cirrhosis (31 patients), defined as Child's B or C liver cirrhosis with complications. Restriction fragment length polymorphism was used for genotyping. RESULTS: Only genotype B and C HBV were identified in our studied cohort. Ninety-one percent of patients suffering from IF were infected by genotype B HBV (p < 0.001 vs asymptomatic carriers, early cirrhosis patients, and decompensated cirrhosis patients). On the contrary, genotype C HBV was the predominant strain at different stages of chronic liver disease; no statistical difference was found on the relative prevalence of genotype B/C HBV among asymptomatic carriers, early cirrhosis patients, and decompensated cirrhosis patients. CONCLUSIONS: Genotype B HBV is associated with IF among chronic HBV-infected patients in Hong Kong, whereas genotype C HBV is more prevalent at all stages of chronic liver disease. Our findings suggested that the two different HBV genotypes might have different pathogenic mechanisms of liver damage.