乙型肝炎病毒前S基因变异与肝病进展的关系

目的探讨HBV前S基因变异与疾病进展的关系。方法收集无症状携带者（ASC）、慢性肝炎（CH）、肝炎肝硬化（LC）、肝细胞癌（HCC）患者血清138份，PCR扩增前S区基因．聚合酶链反应-限制性片段长度多态性检测前S2起始码变异，聚丙烯酰胺凝胶电泳（PAGE）分析前S缺失变异，直接测序确定前CA1896、基本核心启动子（BCP）T1762／A1764变异。数据行X^2检验。结果HCC、LC组前S缺失变异检出率分别为56．3％和42．9％，高于CH组的11．8％和ASC组的8．1％（P〈0．01）。前S2起始码变异检出率在HCC（50．0％）、LC（37．1％）组亦较CH（5．9％）、ASC（0）组高。前S缺失、前S2起始码变异在HBeAg阴性组的检出率分别为37．5％和36．1％，高于HBeAg阳性组的19．7％和7．6％（P〈0．01）。分析前S基因、T1762／A1764、A1896单独或联合变异在HCC、LC组和CH、ASC组的分布，Fisher精确检验表明，T1762／A1764和前S基因的联合变异是影响疾病进展、导致严重肝病的重要因素（P-0）。结论严重肝病患者前s基因变异发生率高，有T1762／A1764联合前S基因变异HBV感染者的肝病易进展。     

慢性乙型肝炎病毒感染者病毒前C区和基本核心启动子区变异检测及意义

目的 探讨乙型肝炎病毒（HBV）前C区和基本核心启动子（BCP）区变异与基因型及疾病进展间的关系。方法 收集HBV携带者（ASC）、慢性乙型肝炎（CHB）、肝炎肝硬化（LC）、肝细胞肝癌（HCC）患者血清148份，用半巢式聚合酶链反应扩增HBV前C／C基因部分片段，产物纯化后直接测序，检测前C区A1896及BCP区T1762／A1764变异。用S基因聚合酶链反应-限制性片段长度多态性分析（PCR-RFLP）方法确定HBV基因型。结果 有128份血清能够成功分型和测序，其中B基因型60份，C基因型68份。在B基因型感染者中前C区A1896变异检出率（48．33％）明显高于C基因型感染者（29．41％，X^2=4．83，P〈0．05）；而BCP区T1762／A1764变异检出率却明显低于C基因型感染者，差异亦有统计学意义（30．00％：73．54%，X^2=24．25。P〈0．05）。前C区A1896变异在CHB、LC、HCC中的阳性检出率分别为46．88％（15/32）、39．39％（13／33）、51．52％（17／33）。与ASC的13．33％（4／30）相比，P分别〈0．05，差异有统计学意义。BCP区T1762／A1764变异检出率在HCC、LC组分别为87．88％（29／33）和72．73％（24／33）．明显高于CHB组的37．50％（12／32）及ASC组10.00％（3／30）（P〈0．05）。结论 前C区A1896变异常见于B基因型感染者，而BCP区T1762/A1764变异C基因型感染者多见。除ASC外．前C区A1896变异与疾病进展关系不大．而BCP区T1762/A1764变异与乙型肝炎进展及顶后相关。     

乙型肝炎病毒前S基因变异与乙型肝炎相关晚期肝病关联性的临床研究

目的研究乙型肝炎病毒(HBV)前S基因变异与乙型肝炎相关晚期肝病及慢加急性肝衰竭(ACLF)的关系。方法收集慢性乙型肝炎(CHB)、乙型肝炎相关性肝硬化(LC)、乙型肝炎相关性肝细胞癌(HCC)患者共71例的血标本及临床资料,提取血清HBV DNA,进行基因分型,PCR扩增HBV DNA前S基因,所得阳性PCR产物进行测序,分析测序结果。结果检测样本中基因型C49例,基因型B21例,混合基因型B+C1例,C为优势基因型。PreS变异率在CHB(不包括ACLF)、LC、HCC三组中分别为18.75%、48.78%、66.67%,CHB组PreS区变异率低于LC组(P0.05)和HCC组(P0.05)。ACLF组PreS区变异率(80%)明显高于CHB组(18.75%)(P0.005)。HBV DNA≥104拷贝/mL在发生PreS区变异组为30例(90.9%),未发生PreS区变异组为19例(50.0%),两组差异有显著统计学意义(P0.001)。Logistic回归分析示HBV DNA≥104拷贝/mL、HBV相关晚期肝病(LC、HCC)与PreS区变异相关(OR值:14.153,95%CI:3.412~58.701;OR值:3.924,95%CI:1.178~13.074)。结论 HBV前S区变异与乙型肝炎相关晚期肝病及肝衰竭的进展有关。     

HBV C基因启动子变异及基因型与肝硬化的相关性研究

目的探讨乙型肝炎病毒(HBV)C基因启动子(CP)和前C区基因变异及HBV基因型与肝硬化的关系。方法通过DNA扩增、基因序列分析检测44例慢性乙型肝炎(CH)、29例肝硬化(LC)患者的血清HBVS基因序列确定其基因型,测定HBVCP和前C区序列确定其变异状况。结果LC患者CP双变异(nt1762A→T和1764G→A)发生率(72.4%)显著高于CH(45.5%),P<0.05;LC患者C型检出率(69.0%)显著高于CH(43.2%),P<0.05;C型HBV感染者的CP双变异发生率(69.2%)显著高于B型感染者(44.1%),P<0.05。结论CP双变异与C基因型密切相关,并且导致病情向肝硬化发展。     

云南地区乙型肝炎病毒基因型分布与临床的相关性

目的: 了解云南地区乙型肝炎病毒基因型分布特征, 探讨其与慢性HBV感染者的性别和年龄、不同临床疾病谱、病毒复制水平的关系.方法:选择云南地区慢性HBV感染者117例, 其中慢性无症状乙型肝炎表面抗原携带者(ASC)26例、慢性乙型肝炎(CHB)55例(轻度21例、中度24例、重度10例)、慢性重型肝炎(CLF)18例、乙肝后肝硬化(LC)11例及原发性肝细胞肝癌(HCC)7例, 采用反向杂交技术(RDB)检测HBV基因型, 并对与其性别年龄、临床分型和病毒复制水平的关系进行分析.结果: 云南地区HBV基因型以B型和C型为主, 分别为41.0%(48/117)和54.7%(64/117) , 并以C型为最多(χ2 = 4.38, P = 0.036);D型1例(0.86%), B、C混合型2例(1.71%), A、C混合型2例(1.71%). B基因型在轻度慢乙肝组所占的比例显著高于中、重度慢乙肝组(χ2 = 8.27、11.98, P = 0.004、0.001)、ASC组(χ2 = 5.46, P = 0.02)、CLF组(χ2 = 4.13, P = 0.042)和LC/HCC组(χ2 = 11.3, P = 0.001). C基因型在LC/HCC组和重度慢乙肝组所占的比例均显著高于轻度慢乙肝组(χ2 = 11.3, P = 0.001;χ2 = 8.78, P = 0.003), 与其他各临床型组间的比较则无显著性差异(P>0.05). C基因型在HBV DNA( )组和HBeAg(-)组r所占的比例均分别显著高于HBV DNA(-)组(χ2 = 6.63, P = 0.01)和HBeAg( )组(χ2 = 7.12, P = 0.008). B基因型在HBV DNA低水平复制组中所占的比例显著高于高水平复制组(χ2 = 4.12, P = 0.042). C基因型在HBV DNA高水平复制组中所占的比例显著高于B基因型(χ2 = 3.89, P<0.05). C基因型在年龄≥30岁组中所占的比例(63.3%)高于年龄<30岁组(45.6%)(χ2 = 3.7, P = 0.05). HBV基因型在性别间的分布无统计学差异(P>0.05)结论:云南地区存在HBV的B、C、D、B C和A C基因型, 以B型和C型为主要基因型, 并以C型为最多. B基因型在轻度慢乙肝的比例显著高于其他各临床型HBV感染者, 并且与HBV的低水平复制和低年龄有关. C基因型主要分布于重度慢乙肝和LC/HCC、HBV DNA高水平复制、年龄≥30岁的患者中. 提示C基因型与慢乙肝重度、肝硬化、肝细胞肝癌及HBV DNA高水平复制关系密切.     

河南省不同地区、不同肝病患者的HBV基因型分布

采用PCR扩增技术,对河南省部分地区315例乙肝感染患者的乙型肝炎病毒(HBV)基因进行分型,并分析其基因型与HBV相关肝病的相关性.结果 显示,本组HBV DNA阳性血清248份,其中HBV基因B型占28.6%,C型占70.2%,D型占1.2%.无症状携带者(ASC)、慢性肝炎(CHB)、重型肝炎(CSL)均以B型为主要基因型;C型在肝硬化中所占比例显著高于ASC和CSL;相关分析表明,肝细胞癌(HCC)与基因D型关系密切.提示河南省部分地区的HBV基因型多数为C型,少数为B型,极少数为D型;基因C型与较严重肝病有关,D型与HCC有一定相关性.     

广东地区原发性肝癌与乙型肝炎病毒基因型的相关性

目的研究广东地区原发性肝癌（HCC）与HBV基因型的相关性。方法2003至2005年慢性HBV感染相关肝脏疾病患者共298例，其中HCC73例，肝硬化（LC）53例，慢性乙型肝炎（CHB）91例，无症状HBV携带者（ASC）81例。采用PCR-限制性片段长度多态性（PCR-RFLP）分析及克隆测序方法对血清HBVDNA进行基因分型，比较各组患者HBV基因型的分布及临床特征。结果298例患者基因型分布为B型142例，占47．65％；C型156例，占52．35％。HBVC基因型在HCC患者分布明显高于其他对照组（X^2=45．20，P〈0．01）。HCC组中男性比例明显高于女性；HCC和LC组平均年龄显著高于其他组。结论广东地区HBV相关性肝病HBV基因型主要为C型和B型，HBVC基因型感染可能为HCC的高危因素之一。     

慢性HBV感染者不同病程阶段HBV前S基因缺失突变的比较分析

目的 探讨慢性HBV感染者不同病程阶段前S(pre-S)基因缺失的临床流行特点及其临床意义. 方法 采用巢式PCR方法扩增测序146例慢性乙型肝炎(chronic hepatitis B, CHB)患者(CHB组)、111例HBV相关肝硬化(liver cirrhosis, LC)患者(LC组)、146例慢加急性肝衰竭(acute-on-chronic liver failure, ACLF)患者(ACLF组)和136例HBV相关肝细胞癌(hepatocellular carcinoma, HCC)患者(HCC组)的HBV pre-S基因(nt 2848-154).分析比较不同组pre-S基因缺失发生率、缺失热点区域和缺失片段长度. 结果 LC组和HCC组HBV pre-S基因缺失率显著高于CHB组(26.1%vs. 15.8%,P=0.040;34.6%vs. 15.8%,P<0.001);LC组pre-S1基因单独缺失率显著高于CHB组(17.1%vs. 4.8%,P=0.001);HCC组pre-S2基因单独缺失率显著高于CHB组(19.1%vs. 4.8%,P<0.001). 不同病程阶段患者发生缺失的热点区域也不相同,CHB组发生缺失的热点区域为nt 3031-3215(30.4%)和nt 24-57(30.4%);LC组为nt 2849-2866(55.2%)和nt 5-55(31.0%);ACLF组为nt 2849-2866(28.6%)和nt 1-54(25.7%);HCC组为nt 5-55(57.4%)和nt 2849-2866(12.8%).不同病程阶段患者发生pre-S基因缺失的片段长度差异无统计学意义. 结论 慢性HBV感染者中,随着疾病进展HBV pre-S基因缺失率呈上升趋势,其中pre-S1基因缺失突变在LC患者中显著增高,pre-S2基因缺失突变在HCC患者中显著增高.pre-S基因缺失可能参与驱动HBV慢性感染的疾病进展.     

88例乙型肝炎病毒携带者前C区1 896位变异分析

目的 研究乙型肝炎病毒(HBV)携带者前C区1 896位变异情况.方法 采用聚合酶链反应(PCR)和酶联定量检测法分析,检测88例HBV携带者(其中HBeAg阳性50例,HBeAg阴性38例,HBV DNA均阳性)前C区1 896位变异.结果 50例HBeAg阳性患者中前C区1 896位变异率为8%,38例HBeAg阴性患者中,其前C区1 896位变异率为31.5%,88例HBV携带者总变异检出率为18.2%.HBV携带者HBeAg阴性组变异率明显高于HBeAg阳性组(P＜0.05).结论 HBV携带者普遍存在前C区1 896变异.     

乙型肝炎病毒基因型与肝细胞癌的关系

目的 研究乙型肝炎病毒(HBV)基因型与肝细胞癌(HCC)相关性的病毒分子基础.方法 应用PCR-RFLP法或测序法测定回顾性随机配对的124例HBsAg阳性HCC患者和124例慢性HBV感染者的HBV基因型;比较HCC患者中不同HBV基因型的临床资料;检测HBV的HBx、Enh2与Bcp基因序列的变异.结果 慢性HBV感染者中HBV基因型B型占62.1%,C型占37.9%,HCC患者中基因B型占41.5%,C型占58.5%,未见其他基因型.基因B、C型的HCC患者平均年龄均在50岁左右.在≤35岁的HCC患者,感染的HBV以B型为主;在36～50岁组中, C型比例明显大于B型;而在50岁以上组中二者无明显差别.感染HBV基因B型HCC患者的血清总胆红素水平高于C型[分别为(56.3±79.5)μmol/L和(23.7±18.3) μmol/L,P=0.015];感染C型者HBeAg阳性率高于B型(分别为34.1%和9.74%,P=0.024);所有发生肝外转移的HCC患者的HBV基因型均为B型.在整个HBx、Enh2与Bcp区,基因B、C型HBV株氨基酸水平变异无明显差别.70.0%基因B型和96.2%C型HBV株发生nt1762/1764的双位点变异.此外,在反式激活区和增强子II区,B型HBV的基因变异明显,C型HBV株共有64个氨基酸发生热点变异,而B型HBV株仅有23个氨基酸发生热点变异.结论 福建省HCC患者HBV基因型以C型为主.C型HBV株在反式激活区的基因变异较大,这可能与感染C型HBV株者更易发生HCC有关.感染基因B型HBV的HCC患者较易发生肝外转移的现象值得进一步探讨.     

Clinical significance of pre-S mutations in patients with genotype C hepatitis B virus infection

We investigated the overall and site-specific prevalence of pre-S mutations and its clinical significance in patients with genotype C hepatitis B virus (HBV) infection. Three hundred subjects were included: 50 asymptomatic carriers (AC), 87 chronic hepatitis (CH), 91 liver cirrhosis (LC) and 72 hepatocellular carcinoma (HCC). Pre-S mutations were determined by nucleotide sequence analysis. Possible correlations between pre-S mutations and clinical/virological parameters were examined. Pre-S mutations were detected in 82 cases (27.3%); it was more frequently found in HCC (43.1%) and LC (35.2%) group than in the CH (20.7%) and AC (2.0%) group. Pre-S2 deletion was the most commonly found mutation (10.7%), followed by pre-S2 start codon mutation (9.7%), pre-S1-S2 deletion (3.0%) and both pre-S2 deletion and start codon mutation (2.7%). Pre-S2 deletion and pre-S2 start codon mutation were more frequently detected in advanced diseases (LC and HCC). Pre-S mutations were associated with older age and higher rates of positive HBV DNA (>/=0.5 pg/mL). Advanced disease and positive HBV DNA were shown to be independent predictors of pre-S mutations by logistic regression analysis. These findings suggest that pre-S mutations, especially pre-S2 deletions and pre-S2 start codon mutations, are common in patients with genotype C HBV infection and are associated with advanced liver disease and active viral replication.     

Molecular epidemiological study of hepatitis B virus in Thailand based on the analysis of pre-S and S genes.

Aims: This study was undertaken to determine the prevalence and characteristics of hepatitis B virus (HBV) genotypes, antigen subtypes, "a" determinant variants and pre-S gene mutations circulating on a large scale in Thailand. Methods: The sequences of the Pre-S1, Pre-S2 and S regions were determined in serum samples of 147 HBsAg and HBV DNA-positive subjects who had been enrolled from the nationwide seroepidemiological survey conducted on 6213 individuals in 2004. Results: The results showed that genotypes C, B and A accounted for 87.1%, 11.6% and 1.3%, respectively. The distribution of the HBV antigen subtypes was: adr (84.4%), adw (14.2%) and ayw (1.4%). Regarding the "a" determinant, 2/43 (4.65%) and 2/104 (1.92%) samples of vaccinated and non-vaccinated subjects, respectively, displayed mutations, all ofwhich were Thr126Asn. Sequencing analysis showed the pre-S mutations in 14 (9.5%) samples, with pre-S2 deletion as the most common mutant (4.1%) followed by pre-S2 start codon mutation (2.9%), both pre-S2 deletion and start codon mutation (2.0%), and pre-S1 deletion (0.7%). The pre-S mutations were associated with older age and higher mean serum HBsAg level. Conclusion: This study demonstrated that HBV genotype/subtype C/adr and B/adw were the predominant strains circulating in Thailand. The "a" determinant variants seemed to be uncommon, and might not be attributed to vaccine-induced mutation.     

Different pre-S deletion patterns and their association with hepatitis B virus genotypes

AIMTo investigate the associations of different types of pre-S deletions with hepatitis B virus (HBV) genotypes.METHODSThe sequences of the pre-S region, basal core promoter (BCP) mutation, and precore (PC) mutation were examined through direct DNA sequencing or clonal analysis and sequencing in 273 HBV carriers, namely 55 asymptomatic carriers, 55 carriers with chronic hepatitis (CH), 55 with liver cirrhosis (LC), 53 with liver cirrhotic hepatocellular carcinoma (LC-HCC), and 55 with noncirrhotic HCC. A total of 126 HBV carriers (46.2%) harbored pre-S deletions. The DNA sequences of pre-S deletion mutants from 43 age-matched genotype B (HBV/B)-infected carriers and 43 age-matched genotype C (HBV/C)-infected carriers were further examined, aligned, and compared.RESULTSNo significant difference was observed in the mean age distribution (P = 0.464), male sex (P = 0.805), viral load (P = 0.635), or BCP mutation (P = 0.117) between the HBV/B and HBV/C groups. However, the rate of PC mutation was significantly higher in the HBV/B-infected carriers than in the HBV/C-infected carriers (P = 0.003). Both genotypes exhibited a high rate of deletion in the C-terminal half of the pre-S1 region and N-terminus of the pre-S2 region (86.0% and 79.1% in the HBV/B group; 69.8% and 72.1% in the HBV/C group, respectively). Epitope mapping showed that deletion in several epitope sites was frequent in both genotypes, particularly pS1-BT and pS2-B2. Conversely, the rate of pS2-B1 deletion was significantly higher in the HBV/B group (72.1% vs 37.2%, P = 0.002), and the rate of pS2-T deletion was significantly higher in the HBV/C group (48.8% vs 25.6%, P = 0.044). Functional mapping showed that the rate of deletion in three functional sites (the nucleocapsid binding site, start codon of M, and site for viral secretion) located in the N-terminus of the pre-S2 region was significantly higher in the HBV/B group (P < 0.05). One type of N-terminus pre-S1 deletion mutant with deletion of the start codon of the L protein was frequently observed in the HBV/C group (20.9% vs 9.3%, P = 0.228), particularly in the LC patients (42.9% vs 12.5%). Different patterns of pre-S deletions were also found between the HBV/B and HBV/C groups according to different clinical outcomes. In CH patients, deletion in the site for polymerized human serum albumin was more frequent in the HBV/B group (88.9% vs 36.4%, P = 0.028). In the LC-HCC patients, the rate of deletion in the pre-S2 region was significantly higher in the HBV/B group than in the HBV/C group (P < 0.05).CONCLUSIONHBV/B- and HBV/C-infected carriers exhibit different patterns of pre-S deletion, which may be associated with the progression of liver diseases.     

Hepatitis B virus pre-S2 start codon mutations in Indonesian liver disease patients

AIM: To identify the prevalence of pre-S2 start codon mutations and to assess their association with liver disease progression. METHODS: The mutations were identified by direct sequencing from 73 asymptomatic carriers, 66 chronic hepatitis (CH), 66 liver cirrhosis (LC) and 63 hepatocellular carcinoma (HCC) patients. Statistical significances were determined using Fisher's exact test, χ 2 test, and t -test analyses whenever appropriate. Pre-S mutation as a risk factor for advanced liver disease was estimated by unconditional logistic regression model adjusted with age, sex, and hepatitis B e antigen (HBeAg). P 0.05 was considered significant. RESULTS: Mutation of the hepatitis B virus (HBV) pre-S2 start codon was found in 59 samples from 268 subjects (22.0%), with higher prevalence in patients with cirrhosis 27/66 (40.9%) followed by HCC 18/63 (28.6%), chronic hepatitis 12/66 (18.2%) and asymptomatic carriers 2/73 (2.7%) (P 0.001). Logistic regression analysis showed that pre-S2 start codon mutation was an independent factor for progressive liver disease. Other mutations, at T130, Q132, and A138, were also associated with LC and HCC, although this was not statistically significant when adjusted for age, sex, and HBeAg. The prevalence of pre-S2 start codon mutation was higher in HBV/B than in HBV/C (23.0% vs 19.1%), whilst the prevalence of T130, Q132, and A138 mutation was higher in HBV/C than in HBV/B. The prevalence of pre-S2 start codon mutation was higher in LC (38.9%) and HCC (40.0%) than CH (5.6%) in HBeAg(+) group, but it was similar between CH, LC and HCC in HBeAg(-) group. CONCLUSION: Pre-S2 start codon mutation was higher in Indonesian patients compared to other Asian countries, and its prevalence was associated with advanced liver disease, particularly in HBeAg(+) patients.     

Mutations in <Emphasis Type="Italic">preS</Emphasis> genes of genotype C hepatitis B virus in patients with chronic hepatitis B and hepatocellular carcinoma

Background Hepatitis B virus (HBV) preS mutations are frequently isolated from patients with severe forms of liver disease. Meanwhile, genotype C has been shown to cause more serious liver disease than genotype B. This study assesses the frequency of preS mutation in Chinese patients with genotype C chronic HBV infection and its relation to liver damage. Methods Seventy-nine persistently infected patients (25 asymptomatic carriers, 28 with chronic hepatitis, and 26 with hepatocellular carcinoma) with genotype C HBV were analyzed. Levels of HBV DNA, hepatitis B e antigen (HBeAg), alanine aminotransferase, and aspartate transaminase and mutations in the preS region were determined. Results The correlations of preS deletion with disease progression were distinct: preS deletion mutations were more commonly found in the hepatocellular carcinoma (HCC) group than in the chronic hepatitis B (CHB) or asymptomatic carrier (ASC) groups, with the frequencies of 38.46% (10/26) in the HCC, 7.14% (2/28) in the CHB, and 4.00% (1/25) in the ASC (P = 0.001) groups. The HBeAg-positive rate and HBV DNA levels were comparable between patients with the preS mutation and those without. Conclusions PreS deletion mutations of genotype C HBV might play a role in HBV-related hepatocarcinogenesis.     

The clinical implications of hepatitis B virus genotype: Recent advances

Outcomes of chronic hepatitis B virus (HBV) infection are heterogeneous. Estimates of annual incidence of cirrhosis and hepatocellular carcinoma (HCC) are 2-10% and 1-3%, respectively. Several viral factors, including HBV genotype, viral load and specific viral mutations, have been associated with disease progression. Among these, HBV genotype is not only predictive of clinical outcomes but has also been associated with response to interferon treatment. Currently, at least 10 HBV genotypes and several subtypes have been identified; they have distinct geographic distribution. Acute infection with genotypes A and D results in higher rates of chronicity than genotypes B and C. Compared to genotype A and B cases, patients with genotypes C and D have lower rates of spontaneous hepatitis B e antigen (HBeAg) seroconversion; when this occurs, it tends to be delayed. HBV genotype C has a higher frequency of basal core promoter (BCP) A1762T/G1764A mutation, pre-S deletion and is associated with higher viral load than genotype B. Similarly, genotype D has a higher prevalence of BCP A1762T/G1764A mutation than genotype A. These observations suggest important pathogenic differences between HBV genotypes. These may contribute to more severe liver disease, including cirrhosis and HCC with genotypes C and D HBV infection. In addition, genotype A and B patients have better responses to interferon-based therapy than genotypes C and D, but there are few consistent differences for direct HBV antivirals. In conclusion, genotyping of chronic HBV infections can help practicing physicians identify those at risk of disease progression and determine optimal anti-viral therapy.     

乙型肝炎病毒家族聚集性感染者的基因型和基因变异特征分析

目的:研究HBV家族聚集性感染者的基因型和基因变异特征．方法:选择HBV聚集性感染家族成员内部基因型完全相同的共27个家族84人,其中HBV 携带者(ASC)29例;慢性活动性肝炎(CAH)23 例;肝硬化(LC)21例;肝细胞癌(HCC)11例;用基因芯片法检验前C1896和BCP1762,1764双突变;用测序法检验HBV基因型,并设相应基因型的HBV感染对照组．结果:B型HBV家族聚集感染者ASC率显著大于C型家族(X2=5．0734,P=0．0243,P<0．05); 其BCP1762．1764双突变的发生率也显著低于 C基因型(X2=22．4000,P=0．0000,P<0．001)．两种基因型的家族聚集感染者组与相应的对照组相比在疾病临床类型方面均无显著差异．结论:检验HBV家族聚集感染者的基因型和／或BCP区1762、1764基因的双突变可以协助疾病的预测分析．     

The predominant genotypes of hepatitis B virus in Thailand

In Thailand, chronic liver disease (CLD) as a consequence of infection with hepatitis B virus (HBV) constitutes a public-health burden. Control and treatment are complicated by the virus exhibiting an unusually high mutation rate, with some genotypes apparently causing more severe disease than others. Restriction-fragment-length-polymorphism (RFLP) analysis of the pre-S region of the viral genome, amplified by PCR, was used to determine which genotypes were most prevalent among Thai patients chronically infected with the virus. The patients were chronic HBV carriers (40) or cases of chronic hepatitis (34), cirrhosis (14) or hepatocellular carcinoma (30). As indicated by the results of earlier studies on CLD patients in South-east Asia, genotype C (68.6%) was clearly predominant. RFLP patterns permitted the C1 (12.7%), C7 (45.7%), C8 (10.2%) and B1 (29.7%) subtypes to be identified. Two samples that could not be typed by RFLP were analysed by direct sequencing, categorized as type C, and tentatively designated as subtype C9. As comparison of the present data with those previously obtained by direct sequencing of PCR products indicates that RFLP analysis is as specific and reliable as sequencing and less expensive and time-consuming, RFLP analysis may be particularly useful for epidemiological studies.     

Association of pre-S deletion mutant of hepatitis B virus with risk of hepatocellular carcinoma

BACKGROUND: Pre-S deletion mutant of hepatitis B virus (HBV) affects the expression of middle and small surface proteins, resulting in intracellular accumulation of large surface protein. The correlation between pre-S deletion mutant and risk of hepatocellular carcinoma (HCC) in hepatitis B virus carriers remains unclear. METHODS: Using molecular assays, pre-S deletion mutant of HBV were determined in 266 patients with chronic HBV genotype B or C infection. They included 202 asymptomatic carriers and 64 HCC patients. RESULTS: The overall prevalence of pre-S deletion mutant was 16.5%. Hepatocellular carcinoma (odds ratio [OR], 3.23; 95% confidence interval [CI], 1.23-8.48, P = 0.02) and genotype C (OR, 3.19; 95%CI, 1.54-6.62, P = 0.002) were independently associated with the presence of pre-S deletion mutant. The prevalence of pre-S deletion mutant was comparable between HCC patients with genotype B and C infection. Nevertheless, in asymptomatic carriers, patients with genotype C infection were significantly associated with the presence of pre-S deletion mutant compared to those with genotype B infection (20.8% vs 7.2%, P = 0.007). Compared with age- and genotype B-matched asymptomatic carriers, young HCC patients (<50 years of age) had a significantly higher frequency of pre-S deletion (3.4% vs 20%, P = 0.04). CONCLUSIONS: Pre-S deletion mutant is more frequent in HBV carriers with genotype C infection, and those with pre-S deletion mutant may be associated with the development of HCC, irrespective of HBV genotype.     

Viral genotype and hepatitis B virus DNA levels are correlated with histological liver damage in HBeAg-negative chronic hepatitis B virus infection

OBJECTIVES: We aimed to study the relationship between the hepatitis B virus (HBV) genotypes, core promoter/precore stop codon mutations, and histological liver damage among hepatitis B e antigen (HBeAg)-negative patients. METHODS: Liver biopsy specimens of 55 HBeAg-negative chronic HBV-infected patients were studied. A histological activity index was scored for degree of necroinflammation (HAI-NI) and fibrosis (HAI-F) as described by Knodell et al. HBV DNA was determined by a cross-linking assay and polymerase chain reaction (PCR) at the core promoter/precore region and the S region. PCR-positive samples were directly sequenced for core promoter and precore mutations and examined by restriction fragment length polymorphism for genotyping. RESULTS: Forty-one males and 14 females at a median age of 43 were studied. HBV DNA was detectable in 32 (58%) and 37 (67%) patients by the cross-linking assay and PCR, respectively, at the time of liver biopsy. The median (range) HAI-NI and HAI-F scores were 5 (1-10) and 2 (0-4), respectively. HBV DNA detectable by either the cross-linking assay or PCR was associated with a higher HAI-NI score. Eleven and 31 patients had genotypes B and C HBV, respectively. Genotype C HBV was associated with higher HAI-NI than genotype B HBV. Core promoter mutations and precore stop codon mutation were detected in 74% and 40% patients, respectively, but they were not associated with higher HAI-NI or HAI-F scores. CONCLUSIONS: Detectable HBV DNA and genotype C HBV, but not core promoter or precore stop codon mutations, are associated with more severe liver damage in HBeAg-negative patients.