慢加急性乙型肝炎肝衰竭患者乙型肝炎病毒前C/CP区变异研究进展*

慢加急性肝衰竭（ACLF）是我国肝衰竭的主要类型,其病情发展迅速、预后不良、病死率较高。在我国,乙型肝炎病毒（HBV）感染是导致ACLF的主要病因,其中HBV前C（PC）/核心启动子（CP）区基因变异与ACLF的发生密切相关。本文重点介绍HBV PC/CP区基本结构和功能、PC/CP区变异后生物学特性的改变、ACLF的免疫病理损伤机制、PC/CP区变异与ACLF疾病进展的临床意义等方面的研究进展。     

乙型肝炎病毒e抗原阴性慢性乙型肝炎与前C基因及C基因变异关联性临床研究

目的临床观察乙型肝炎病毒e抗原（HBeAg）阴性的慢性乙型肝炎（e-CHB）与前C基因及C基因变异的关联性。方法将慢性乙型肝炎193例进行血清HBeAg、乙型肝炎病毒脱氧核糖核酸（HBV-DNA）水平、前C基因核苷酸1896G→A点突变及C基因核苷酸1762碱基A→T和1764G→A联合突变的检测。结果慢性乙型肝炎193例中,①HBeAg阴性70例（36.27%）,HBeAg阳性123名（63.73%）。②HBeAg阴性前C基因变异率76%,HBeAg阳性前C基因变异率31%,二者比较差异有统计学意义（P〈0.05）;HBeAg阴性C基因变异率51%,HBeAg阳性C基因变异率30%,二者比较差异无统计学意义（P〉0.05）。③HBeAg阳性患者中,前C基因或C基因变异群的HBV-DNA水平低于未变异群,差异比较有统计学意义（P〈0.05）,而HBeAg阴性患者中,前C基因或C基因变异群与非变异群比较,血清HBV-DNA水平差异比较均无统计学意义（P〉0.05）。结论在e-CHB中,前C基因变异与HBeAg转阴具有密切关系,而C基因变异与HBeAg转阴关系不明确;前C基因和C基因变异不能增强病毒毒性,与疾病严重程度可能无关。     

Mutations of polymerase,precore and core promoter gene in hepatitis B virus during 5-year lamivudine therapy

BACKGROUND/AIMS: The effects of long-term lamivudine therapy on changes in polymerase and precore/core promoter mutations are unknown. The aim of this study was to determine the changes in these regions in patients with chronic hepatitis B virus (HBV) infection treated with lamivudine for 5 years. METHODS: Serum samples obtained from 16 patients at the beginning of and during therapy were polymerase chain reaction-amplified, and nucleotide sequences of HBV analyzed. RESULTS: By the end of 5-year therapy, mutations in YMDD motif emerged in ten patients. Mutations in L526M, M550V and M550I in polymerase were found in seven, six and six patients, respectively. The L526M mutant was found at the time or after detection of M550V/I mutant in six of seven patients. At baseline, precore and core promoter mutations were found in eight and 12 of 16 patients, respectively. Mutants of precore and core promoter were replaced by wild-type virus in each of three patients infected with mutants at 1 year. However, at 5 years of treatment, precore and core promoter mutations reappeared in some patients. CONCLUSIONS: Our data showed that lamivudine initially selected from precore/core promoter mutants to wild-type virus, but precore mutation reappeared during prolonged therapy.     

基因芯片技术检测肝细胞癌前C区/BCP区基因突变

目的应用基因芯片技术探讨HBV慢性感染并发肝细胞癌(HCC)前C区/BCP区基因突变的临床意义。方法应用基因芯片杂交技术检测46例HBV慢性感染并发肝细胞癌前C区A1896、A1899及BCP区nt1762、nt1764四位点突变,比较各位点突变的发生率;据乙肝血清学标志熏将研究对象分为HBeAg阳性组、HBeAg阴性组两组,比较前C区/BCP区变异与HBeAg分泌障碍的关系,分析前C区/BCP区基因突变与血清HBVDNA定量的关系。结果①用基因芯片法测定46例患者,阳性率91.3%(42/46),A1896突变率52.4%,A1899突变率19%熏nt1762/nt1764联合突变率66.7%。②HBeAg阴性组与HBeAg阳性组比较,A1896突变率、nt1762nt1764联合突变率及多位点突变率明显为高,P<0.05。前C区/BCP区变异组与非变异组比较,HBVDNA定量无显著性差异。结论应用基因芯片法可一次同时检测乙型肝炎病毒多个突变位点熏HBV持续慢性感染并发的HCC前C区/BCP区变异的发生率较高,该变异与HBeAg分泌障碍有关,但与HBVDNA复制水平并无明显相关性。     

乙型肝炎病毒前C区A83变异株的临床检测及分析

目的 了解ＨＢＶ前Ｃ区Ａ８３变异的临床意义。方法 用错配ＰＣＲ－ＲＦＬＰ检测ＨＢＶ感染者血清ＨＢＶ前Ｃ区Ａ８３变异株。结果 该变异株在急性肝炎未检出;在慢性肝炎、肝硬化和重型肝炎检出率分别为６６．７％、４８．９％和４５．５％;慢性无症状ＨＢＶ携带者为３．３％;各型肝炎均以血清抗ＨＢｅ（＋）组的变异检出率最高;肝硬化血清变异株阳性者的腹水发生率和肝功功能异常率较阴性者无显著差别。结论 机体对ＨＢｅＡ     

乙型肝炎病毒前C区变异株和野生株感染者血清HBV DNA水平

为探索HBV前C区变异株和野生株感染者血清HBA水平,我们用3’末端限定引物扩增HBV变异株和野生株DNA,并采用信号引物能量转移法对50例患者进行DNA定量分析。结果显示,15例变异株患者DNA含量为1.26×10~5—8.52×10~9拷贝/ml,而野生株含量明显低于变异株(P<0.01),为3.37×10~3—9.46×10~7拷贝/ml。提示变异的病毒可以逃避宿主的免疫压力而大量复制,使感染持续。     

Epigallocatechin gallate inhibits HBV DNA synthesis in a viral replication - inducible cell line

AIM:To analyze the antiviral mechanism of Epigallocatechin gallate(EGCG)against hepatitis B virus(HBV) replication.METHODS:In this research,the HBV-replicating cell line HepG2.117 was used to investigate the antiviral mechanism of EGCG.Cytotoxicity of EGCG was analyzed by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.Hepatitis B virus e antigen(HBeAg)and hepatitis B virus surface antigen(HBsAg)in the supernatant were detected by enzyme-linked immunosorbent assay.Precore mRNA and pregeno...     

Enhanced intracellular retention of a hepatitis B virus strain associated with fulminant hepatitis

A plasmid carrying 1.3-fold HBV genome was constructed from a HBV strain that caused five consecutive cases of fulminant hepatitis (pBFH2), and HepG2 cells were transfected with pBFH2 or its variants. The pBFH2 construct with A1762T/G1764A, G1862T, and G1896A showed the largest amount of core particle-associated intracellular HBV DNA, but no significant increase of extracellular HBV DNA in comparison with the wild construct, suggesting that these mutations might work together for retention of the replicative intermediates in the cells. The retention might relate to the localization of hepatitis B core antigen (HBcAg) in the nucleus of HepG2, which was observed by confocal fluorescence microscopy. HBcAg immunohistochemical examination of liver tissue samples obtained from the consecutive fulminant hepatitis patients showed stronger staining in the nucleus than acute hepatitis patients. In conclusion, the fulminant HBV strain caused retention of the core particles and the core particle-associated HBV DNA in the cells.