Liver histopathological lesions is severe in patients with normal alanine transaminase and low to moderate hepatitis B virus DNA replication

BACKGROUND Chronic hepatitis B virus(HBV)infection remains a major global public health problem.Chronic hepatitis B(CHB)patients can be divided into treatment indication and non-treatment indication individuals according to alanine transaminase(ALT),HBV DNA,serum hepatitis B e antigen status,disease status[liver cirrhosis,hepatocellular carcinoma(HCC),or liver failure],liver necroinflammation or fibrosis,patients’age,and family history of HCC or cirrhosis.For example,normal ALT patients in‘immune-tolerant’phase with HBV DNA higher than 10^(7)or 2×10^(7)IU/mL,and those in‘inactive-carrier’phase with HBV DNA lower than 2×10^(3)IU/mL do not require antiviral therapy.However,is it reasonable to set the defined values of HBV DNA as the fundamental basis to estimate the disease state and to determine whether to start treatment?In fact,we should pay more attention to those who do not match the treatment indications(grayzone patients both in the indeterminate phase and in the‘inactive-carrier’phase).AIM To analyze the correlation of HBV DNA level and liver histopathological severity,and to explore the significance of HBV DNA for CHB with normal ALT.METHODS From January 2017 to December 2021,a retrospective cross-sectional set of 1299 patients with chronic HBV infection(HBV DNA>30 IU/mL)who underwent liver biopsy from four hospitals,including 634 with ALT less than 40 U/L.None of the patients had received anti-HBV treatment.The degrees of liver necroinflammatory activity and liver fibrosis were evaluated according to the Metavir system.On the basis of the HBV DNA level,patients were divided into two groups:Low/moderate replication group,HBV DNA≤10^(7)IU/mL[7.00 Log IU/mL,the European Association for the Study of the Liver(EASL)guidelines]or≤2×10^(7)IU/mL[7.30 Log IU/mL,the Chinese Medical Association(CMA)guidelines];high replication group,HBV DNA>10^(7)IU/mL or>2×10^(7)IU/mL.Relevant factors(demographic characteristics,laboratory parameters and noninvasive models)for liver histopathological severity were analyzed by univariate analysis,logistics analysis and propensity score-matched analysis.RESULTS At entry,there were 21.45%,24.29%,and 30.28%of the patients had liver histopathological severities with≥A2,≥F2,and≥A2 or/and≥F2,respectively.HBV DNA level(negative correlation)and noninvasive model liver fibrosis 5 value(positive correlation)were independent risk factors for liver histopathological severities(liver necroinflammation,liver fibrosis,and treatment indication).The AUROCs of the prediction probabilities(PRE_)of the models mentioned above(<A2 vs≥A2,<F2 vs≥F2,<A2 and<F2 vs≥A2 or/and≥F2)were 0.814(95%CI:0.770-0.859),0.824(95%CI:0.785-0.863),and 0.799(95%CI:0.760-0.838),respectively.HBV DNA level(negative correlation)was still an independent risk factor when diagnostic models were excluded,the P values(<A2 vs≥A2,<F2 vs≥F2,<A2 and<F2 vs≥A2 or/and≥F2)were 0.011,0.000,and 0.000,respectively.For the propensity score-matched pairs,whether based on EASL guidelines or CMA guidelines,the group with significant liver histology damage(≥A2 or/and≥F2)showed much lower HBV DNA level than the group with non-significant liver histology damage(<A2 and<F2).Patients in the moderate replication group(with indeterminate phase)had the most serious liver disease pathologically and hematologically,followed by patients in the low replication group(with‘inactive-carrier’phase)and then the high replication group(with‘immune-tolerant’phase).CONCLUSION HBV DNA level is a negative risk factor for liver disease progression.The phase definition of CHB may be revised by whether the level of HBV DNA exceeds the detection low limit value.Patients who are in the indeterminate phase or‘inactive carriers’should receive antiviral therapy.

Correlation between HBeAg and Hepatitis B Virus DNA and RNA Levels in Diverse Liver Disease Cohorts

Objective:To investigate the disparities and associations between HBV DNA and HBV RNA in various liver disease groups with respect to HBeAg status.Methods:Between September 2020 and September 2023,90 patients diagnosed with chronic hepatitis B(CHB),74 patients diagnosed with liver cirrhosis(LC),and 102 patients diagnosed with hepatocellular carcinoma(HCC)from the Department of Gastroenterology or Infection at the First Affiliated Hospital of Xi’an Jiaotong University were selected.HBV DNA,HBV RNA,and HBeAg quantitative tests were conducted using serum samples from the same patients.Results:In the three groups of cases,the HBV RNA load was higher when HBeAg was positive than when HBeAg was negative,and this difference was statistically significant.Only in the HCC group was the HBV DNA load significantly higher when HBeAg was positive than when HBeAg was negative.Additionally,there was a positive correlation between HBV DNA and HBV RNA regardless of HBeAg status.Conclusion:During HBeAg conversion,HBV RNA demonstrates a more sensitive response than HBV DNA.As CHB progresses to LC or HCC,HBV RNA exhibits better diagnostic value than HBV DNA.

不同核酸提取方法对HBV-DNA检测性能验证情况分析

目的评估2种乙型肝炎病毒(HBV)-DNA提取方法及2家检测试剂的性能,有助于选择优化提取试剂和检测试剂。方法2023年4月采用达安全自动核酸提取仪提取法(磁珠法)和手工提取法(一步法),并用达安和圣湘2种HBV-DNA试剂检测,对其进行精密度、正确度、线性范围、检出限及抗干扰能力等性能进行验证和评价。结果达安全自动核酸提取仪提取达安试剂检测、手工提取达安试剂检测和手工提取圣湘试剂检测在精密度、正确度、线性范围、检出限方面验证结果均达标;达安全自动核酸提取仪提取圣湘试剂检测在低值检测中变异系数大于5%,最低检测限验证不合格;抗干扰能力方面,全自动核酸提取仪提取的2.0 g/dL血红蛋白浓度的样本用达安和圣湘试剂检测结果均不受影响。手工提取甘油三酯浓度达3000 mg/dL的样本用达安和圣湘试剂检测的结果均不受影响。结论不同厂家的提取和检测试剂避免混用,达安和圣湘试剂对HBV-DNA定量检测的结果均符合要求。

阿拉尔市某医院HBsAg阳性孕妇血清标志物模式分布与HBV-DNA载量分析

目的分析阿拉尔市某医院的乙型肝炎病毒表面抗原(HBsAg)阳性孕妇乙型肝炎病毒(HBV)感染血清标志物模式与HBV-DNA载量之间的关系,为监控孕期HBV感染和预防阻断HBV母婴传播提供理论依据。方法选取2021年10月至2023年10月期间在新疆生产建设兵团第一师阿拉尔医院产科建档及生产的HBsAg阳性孕妇为研究对象,通过磁微粒化学发光法检测孕妇五项HBV血清标志物包括测HBsAg和乙肝病毒表面抗体(HBsAb)、乙肝病毒e抗原(HBeAg)、乙肝病毒e抗体(HBeAg)以及乙肝病毒核心抗体(HBcAb),并利用荧光定量PCR检测HBV-DNA载量,分析HBV-DNA载量以及孕妇HBV感染模式对新生儿的影响。结果共纳入145例HBsAg阳性孕妇,HBV感染模式以感染模式Ⅱ[HbsAg(+)、HBeAb(+)和HBcAb(+)]为主,占62.76%。HBV-DNA阳性(>0.5×10^(3)IU/mL)阳性率为63.45%(92/145),不同HBV感染模式的HBsAg阳性孕妇HBV-DNA阳性率及载量分布情况比较差异有统计学意义(χ^(2)=16.532、64.367,P<0.05),主要表现为感染模式Ⅰ比例随HBV-DNA载量升高而增高。同时,HBV-DNA阳性组随HBeAg浓度升高而比例增高,而HBV-DNA阴性组正好相反,Spearman相关分析表明HBsAg阳性孕妇的HBeAg浓度与HBV DNA载量呈现明显正相关性(r=0.327,P<0.05)。不同HBV感染模式的HBsAg阳性孕妇的新生儿脐带血HBV阳性率比较差异有统计学意义(χ^(2)=16.851,P=0.002),同时HBsAg阳性孕妇的新生儿脐带血HBV阳性率随着HBV-DNA载量增高而明显增高,差异有统计学意义(χ^(2)=15.062,P=0.005)。结论HBsAg阳性孕妇血清标志物模式与HBV-DNA病毒载量密切相关,产前筛查对孕产妇及新生儿的乙肝预防及干预有重要意义,是母婴传播防控的重点。

妊娠合并慢性乙型肝炎患者乙肝标志物、前S1抗原与HBV-DNA的关系研究

目的 研究妊娠合并慢性乙型肝炎(CHB)患者乙肝标志物、前S1抗原(Pre-S1Ag)与乙型肝炎病毒核酸(HBV-DNA)的关系。方法 选取2022年5月至2023年12月我院收治的100例妊娠合并CHB患者为研究对象,依据HBV-DNA定量测定结果将其分为阳性组与阴性组,每组50例。比较两组的乙肝标志物、Pre-S1Ag水平、肝功能指标及不良妊娠结局;分析妊娠合并CHB患者乙肝标志物、Pre-S1Ag以及各项肝功能指标与HBV-DNA的相关性。结果 阳性组的乙型肝炎表面抗原(HBsAg)、乙型肝炎e抗原(HBe Ag)、Pre-S1Ag水平均高于阴性组,乙型肝炎表面抗体(HBsAb)、乙型肝炎e抗体(HBeAb)、乙型肝炎核心抗体(HBcAb)水平低于阴性组(P<0.05)。阳性组的各项肝功能指标水平均高于阴性组(P<0.05)。阳性组的剖宫产、胎膜早破、产后出血及羊水粪染发生率均高于阴性组(P<0.05)。Pearson相关性分析结果显示,妊娠合并CHB患者HBsAg、HBe Ag、Pre-S1Ag及各项肝功能指标均与HBV-DNA呈正相关,HBsAb、HBeAb及HBcAb与HBV-DNA呈负相关(P<0.05)。结论 妊娠合并CHB患者的乙肝标志物、Pre-S1Ag以及肝功能指标均与HBV-DNA密切相关。

DNA-based vaccination induces humoral and cellular immune responses against hepatitis B virus surface antigen in mice without activation of Cmyc

AIM To develop a safe and effective DNAvaccine for inducing humoral and cellularimmunological responses against hepatitis Bvirus surface antigen(HBsAg).METHODS BALB/c mice were inoculated withNV-HB/s,a recombinant plasmid that had beeninserted S gene of hepatitis B virus genome andcould express HBsAg in eukaryotes.HBsAgexpression was measured by ABC immunohis-tochemical assay,generation of anti-HBs byELISA and cytotoxic T lymphocyte(CTL),byMTT method,existence of vaccine DNA bySouthern blot hybridization and activation ofoncogene C-myc by in situ hybridization,RESULTS With NV-HB/s vaccination byintramuscular injection,anti-HBs was initiallypositive 2 weeks after inoculation while all micetested were HBsAg positive in the muscles.Thetiters and seroconversion rate of anti-HBs weresteadily increasing as time went on and weredose-dependent.All the mice inoculated with100 μg NV-HB/s were anti-HBs positive onemonth after inoculation,the titer was 1:1024 ormore.The humoral immune response was similarinduced by either intramuscular or intradermalinjection.CTL activities were much stronger(45.26%)in NV-HB/s DNA immunized mice as compared with those(only 6%)in plasma-derived HBsAg vaccine immunized mice.Twomonths after inoculation,all muscle sampleswere positive by Southern-blot hybridization forNV.HB/s DNA detection,but decreased to 25%and all were undetectable by in situhybridization after 6 months.No oncogene C-myc activation was found in the muscle ofinoculation site.CONCLUSION NV-HB/s could generatehumoral and cellular immunological responsesagainst HBsAg that had been safely expressed insitu by NV-HB/s vaccination.

HBV感染相关性肝细胞癌患者血甲胎蛋白、转氨酶水平与HBV-DNA载量和病情进展的关系

目的探讨乙型肝炎病毒(HBV)感染相关性肝细胞癌(HCC)患者血甲胎蛋白(AFP)、转氨酶水平与HBV-DNA载量和病情进展的关系。方法回顾性分析2022年1月至2023年4月本院收治的50例HBV感染相关性HCC患者资料并设为HCC组,另筛选同期HBV相关肝硬化(LC)和慢性乙型肝炎(CHB)患者资料各30例设为LC组和CHB组,比较三组血AFP及转氨酶水平;比较HCC组不同HBV-DNA载量患者AFP及转氨酶水平差异,并分析肝癌组患者AFP及转氨酶水平与病情进展的关系。结果HCC组患者AFP和丙氨酸氨基转移酶(ALT)水平均高于CHB组和LC组(P<0.05);50例HCC患者中,中低分化及Ⅲ~Ⅳ期患者血AFP和ALT水平高于高分化及Ⅰ~Ⅱ期患者(P<0.05);HBV-DNA高载量患者血AFP和ALT水平高于低载量患者(P<0.05),且患者HBV-DNA载量与其血AFP和ALT水平呈正相关(P<0.05)。结论HBV感染相关性HCC患者血AFP和ALT水平显著提升,且血AFP和转氨酶水平与HBV-DNA载量、肿瘤分期分化程度关系密切,二者对临床评估HBV感染相关性HCC病情进展有一定提示作用。

Covalently closed-circular hepatitis B virus DNA reduction with entecavir or lamivudine

AIM: To investigate the reduction in hepatitis B virus(HBV) covalently closed-circular DNA(ccc DNA) with entecavir(ETV) or lamivudine(LAM). METHODS: This analysis included patients who had participated in the randomized Phase Ⅲ study ETV-022 comparing ETV vs LAM in nucleos(t)ide-naive, HBe Agpositive patients. Patients received ETV(0.5 mg daily) or LAM(100 mg daily) for a minimum of 52 wk. Patients were eligible to participate in this sub-study if they had paired biopsies at baseline and week 48 with evaluable measurements for hepatic HBV ccc DNA and total hepatic HBV DNA. The main objective was to compare changes in hepatic HBV ccc DNA and total hepatic HBV DNA at week 48 of ETV or LAM treatment, which was a secondary endpoint of study ETV-022. Additional post hoc analyses included linear regression analyses to assess associations of baseline levels and on-treatment changes of ccc DNA with other baseline factors [sex,age, serum HBV DNA, alanine aminotransferase(ALT), Knodell necroinflammatory score, Ishak fibrosis score, total hepatic HBV DNA, and HBV genotype], or ontreatment factors(changes from baseline at week 48 in serum HBV DNA, ALT, Knodell necroinflammatory score, Ishak fibrosis score, total hepatic HBV DNA, and HBe Ag loss at week 48).RESULTS: Overall, 305 patients(ETV = 159; LAM = 146) of ETV-022 had paired baseline and week 48 liver biopsies with evaluable measurements for hepatic HBV ccc DNA and total hepatic HBV DNA, and were included in this analysis. Baseline demographics and disease characteristics were comparable between the two arms. After 48 wk, ETV resulted in significantly greater reductions in hepatic HBV ccc DNA [-0.9 log10 copies/human genome equivalent(HGEq) vs-0.7 log10 copies/HGEq; P = 0.0033] and total hepatic DNA levels(-2.1 log10 copies/HGEq vs-1.6 log10 copies/HGEq; P < 0.0001) than LAM. Virologic, biochemical, and histologic response rates at week 48 were also greater with ETV than with LAM. Baseline HBV ccc DNA levels were positively associated with baseline levels of serum HBV DNA and total hepatic HBV DNA, and negatively associated with HBV genotype F. On-treatment changes in HBV ccc DNA levels were negatively associated with baseline levels of serum HBV DNA and baseline ALT, and were positively associated with on-treatment changes in the levels of serum HBV DNA, total hepatic HBV DNA levels, and ALT, change in Knodell necroinflammatory score, and HBe Ag loss.CONCLUSION: Forty-eight weeks of ETV resulted in greater reductions in ccc DNA and total hepatic HBV DNA than LAM, but long-term therapy may be needed for ccc DNA elimination.

Individualized management of pregnant women with high hepatitis B virus DNA levels

Hepatitis B is a major health concern in the Asia-Pacific region, and is endemic in China, Southeast Asia, and Africa. Chronic hepatitis B virus (HBV) infection may cause hepatic cirrhosis and liver cancer. It is estimated that there are more than 350 million chronic HBV carriers worldwide, of whom approximately one quarter will die of chronic hepatitis B-related liver diseases. HBV is transmitted horizontally through blood and blood products or by sexual transmission, and vertically from mother to infant. Perinatal infection is the predominant mode of transmission in countries with a high prevalence of hepatitis B surface antigen (HBsAg) carriage, and perinatal transmission leads to high rates of chronic infection. Therefore, it is important to prevent the mother-to-child transmission (MTCT) of HBV. Research has shown that pregnant women with high HBV DNA levels have an increased risk of MTCT. However, most of the obstetrics guidelines do not make a distinction between pregnant women with high HBV DNA levels and those who are HBsAg positive only. This review addresses the management of pregnant women with high levels of HBV viremia, in terms of antiviral therapy, use of hepatitis B immunoglobulin (HBIG), the combined application of hepatitis B vaccine and HBIG, choice of delivery mode and feeding practices. (C) 2014 Baishideng Publishing Group Inc. All rights reserved.

Relationship between hepatitis B virus DNA levels and liver histology in patients with chronic hepatitis B

AIM： To study the relationship between hepatitis B virus （HBV） DNA levels and liver histology in patients with chronic hepatitis B （CHB） and to determine the prevalence and characteristics of hepatitis B e antigen （HBeAg） negative patients.METHODS： A total of 213 patients with CHB were studied, and serum HBV DNA levels were measured by the COBAS Amplicor HBV Monitor test. All patients were divided into two groups according to the HBeAg status.The correlation between serum HBV DNA levels and liver damage （liver histology and biochemistry） was explored.RESULTS： Of the 213 patients with serum HBV DNA levels higher than 10^5 copies/mL, 178 （83.6%） were HBeAg positive, 35 （16.4%） were HBeAg negative. The serum HBV DNA levels were not correlated to the age,history of CHB, histological grade and stage of liver disease in either HBeAg negative or HBeAg positive patients. There was no correlation between serum levels of HBV DNA and alanine aminotransferanse （ALT）,aspartate aminotrans-ferase （AST） in HBeAg positive patients. In HBeAg negative patients, there was no correlation between serum levels of HBV DNA and AST,while serum DNA levels correlated with ALT （r = 0.351, P = 0.042）. The grade （G） of liver disease correlated with ALT and AST （P 〈 0.05, r = 0.205, 0.327 respectively）in HBeAg positive patients. In HBeAg negative patients,correlations were shown between ALT, AST and the G （P 〈 0.01, and r = 0.862, 0.802 respectively）. HBeAg negative patients were older （35 ± 9 years vs 30 ±9 years, P 〈 0.05 ） and had a longer history of HBV infection （8 ± 4 years vs 6 ± 4 years, P 〈 0.05） and a lower HBV DNA level than HBeAg positive patients （8.4± 1.7 Log HBV DNA vs 9.8 ± 1.3 Log HBV DNA, P 〈0.001）. There were no significant differences in sex ratio,ALT and AST levels and liver histology between the two groups.CONCLUSION： Serum HBV DNA level is not correlated to histological grade or stage of liver disease in CHB patients with HBV DNA more than 10^5 copies/mL.Compared to HBeAg positive patients, HBeAg negative patients are older and have a lower HBV DNA level and a longer HBV infection history. There is no significant difference in sex ratio, ALT and AST levels and liver histology between the two groups.

Hepatitis B virus DNA is more powerful than HBeAg in predicting peripheral T-lymphocyte subpopulations in chronic HBV-infected individuals with normal liver function tests

AIM:To investigate the peripheral T-lymphocyte subpopulation profile,and its correlations with hepatitis B virus(HBV) replication level in chronic HBV-infected(CHI) individuals with normal liver function tests(LFTs) . METHODS:Frequencies of T-lymphocyte subpopu-lations in peripheral blood were measured by flow cytometry in 216 CHI individuals. HBV markers were detected with ELISA. Serum HBV DNA load was assessed with quantitative real-time PCR. Information of age at HBV infection,and maternal HBV infection status was collected. ANOVA linear trend test and linear regression were used in statistical analysis. RESULTS:CHI individuals had significantly decreased relative frequencies of CD3+,CD4+ subpopulationsand CD4+/CD8+ ratio,and increased CD8+ subset percentage compared with uninfected individuals(all P < 0.001) . There was a significant linear relationship between the load of HBV DNA and the parameters of T-lymphocyte subpopulations(ANOVA linear trend test P < 0.01) . The parameters were also significantly worse among individuals whose mothers were known to be HBV carriers,and those having gained infection before the age of 8 years. In multiple regressions,after adjustment for age at HBV infection and status of maternal HBV infection,log copies of HBV DNA maintained its highly significant predictive coefficient on T-lymphocyte subpopulations,whereas the effect of HBeAg was not significant. CONCLUSION:HBV DNA correlates with modification in the relative T-lymphocyte subpopulation frequencies. High viral load is more powerful than HBeAg in predicting the impaired balance of T-cell subsets.

Curcumin inhibits hepatitis B virus infection by downregulating ccc DNA-bound histone acetylation

AIM To investigate the potential effect of curcumin on hepatitis B virus(HBV) covalently closed circular DNA(ccc DNA) and the underlying mechanism.METHODS A Hep G2.2.15 cell line stably transfected with HBV was treated with curcumin, and HBV surface antigen(HBs Ag) and e antigen(HBe Ag) expression levels were assessed by ELISA. Intracellular HBV DNA replication intermediates and ccc DNA were detected by Southern blot and real-time PCR, respectively. The acetylation levels of histones H3 and H4 were measured by Western blot. H3/H4-bound ccc DNA was detected by chromatin immunoprecipitation(Ch IP) assays. The deacetylase inhibitors trichostatin A and sodium butyrate were used to study the mechanism of action for curcumin. Additionally, short interfering RNAs(si RNAs) targeting HBV were tested along with curcumin.RESULTS Curcumin treatment led to time-and dose-dependent reductions in HBs Ag and HBe Ag expression and significant reductions in intracellular HBV DNA replication intermediates and HBV ccc DNA. After treatment with 20 μmol/L curcumin for 2 d, HBs Ag and ccc DNA levels in Hep G2.2.15 cells were reduced by up to 57.7%(P < 0.01) and 75.5%(P < 0.01), respectively, compared with levels in non-treated cells. Meanwhile, time-and dose-dependent reductions in the histone H3 acetylation levels were also detected upon treatment with curcumin, accompanied by reductions in H3-and H4-bound ccc DNA. Furthermore, the deacetylase inhibitors trichostatin A and sodium butyrate could block the effects of curcumin. Additionally, transfection of si RNAs targeting HBV enhanced the inhibitory effects of curcumin.CONCLUSION Curcumin inhibits HBV gene replication via downregulation of ccc DNA-bound histone acetylation and has the potential to be developed as a ccc DNA-targeting antiviral agent for hepatitis B.

Novel therapeutic approaches for hepatitis B virus covalently closed circular DNA

Hepatitis B virus(HBV) infection is a major global health problem. Although current therapies, such as the use of nucleos(t)ide analogs, inhibit HBV replication efficiently, they do not eliminate covalently closed circular DNA(ccc DNA), which persists in hepatocyte nuclei. As HBV ccc DNA is a viral transcription template, novel therapeutic approaches to directly target HBV ccc DNA are necessary to completely eradicate persistent HBV infections. HBV ccc DNA levels in HBV-infected human liver cells are extremely low; thus, more reliable and simple measurement methods are needed to correctly monitor their levels during therapeutic treatment. Although reverse transcription-polymerase chain reaction or Southern blot procedures are currently used in research studies, these methods are not completely reliable and are also time-consuming and labor-intensive. Genome editing technologies, such as zinc finger nucleases, transcription activator-like effector nucleases, and the clustered regularly interspaced short palindromic repeats/Cas9(CRISPR/Cas9) system, which are designed to target specific DNA sequences, represent highly promising potential therapeutic tools. In particular, the CRISPR/Cas9 system is an easily customizable sequencespecific nuclease with high flexibility and may be the most feasible approach to target HBV ccc DNA. Further research to develop easier, safer, and more effective protocols should be pursued.

Detection of hepatitis B virus DNA by real-time PCR using TaqMan-MGB probe technology

AIM: To develop a real-time PCR for detecting hepatitis B virus-(HBV) DNA based on TaqMan technology using a new MGB probe.METHODS: Plasmid containing the sequence of X gene (1414-1744 nt) was constructed as HBV-DNA standard for quantitative analysis. A TaqMan-MGB probe between primers for amplification was designed to detect PCR products. The interested sequence contained in the plasmid and in clinical specimens was quantitatively measured.RESULTS: The detection limit of the assay for HBV DNA was 1 genome equivalent per reaction. A linear standard curve was obtained between 100 and 109 DNA copies/reaction (r＞0.990). None of the negative control samples showed false-positive reactions in duplicate. HBV DNA was detected in 100% (50/50) of HBV patients with HbeAg, and in 72.0% (36/50) with HBsAg, HBeAb and HBcAb. The coefficient of variation for both intra- and inter-experimental variability demonstrated high reproducibility and accuracy.CONCLUSION: Real-time PCR based on TaqMan-MGB probe technology is an excellent method for detection of HBV DNA.

Existence and significance of hepatitis B virus DNA in kidneys of IgA nephropathy

AIM: To investigate the existence and significance of hepatitis B virus (HBV) DNA in the pathogenesis of IgA nephropathy(IgAN).METHODS: Fifty cases of IgAN with HBV antigenaemia and/or hepatitis B virus antigens (HBAg, or HBsAg, HBcAg)detected by immunohistochemistry in renal tissues were enrolled in our study. The distribution and localization of HBV DNA were observed using in situ hybridization.Southern blot analysis was performed to reveal the state of renal HBV DNA.RESULTS: Among the 50 patients with IgAN, HBs antigenemia was detected in 17 patients (34%). HBAg in renal tissues was detected in 48 patients (96%), the positive rate of HBAg, HBsAg, and HBcAg was 82% (41/50), 58% (29/50),and 42% (21/50) in glomeruli, respectively; and was 94%(47/50), 56% (28/50) and 78% (39/50) in tubular epithelia,respectively. Positive HBV DNA was detected in 72% (36/50)and 82% (41/50) cases in tubular epithelia and glomeruli respectively by in Situ hybridization, and the positive signals were localized in the nuclei of tubular epithelial cells and glomerular mesangial cells as well as infiltrated interstitial lymphocytes. Moreover, 68% (34/50) cases were proved to be HBV DNA positive by Southern blot analysis, and all were the integrated form.CONCLUSION: HBV infection might play an important role in occurrence and progress of IgAN. In addition to humoral immune damages mediated by HBAg-HBAb immune complex,renal tissues of some IgAN are directly infected with HBV and express HBAg in situ, and the cellular mechanism mediated by HBV originating from renal cells in situ may also be involved in the pathogenesis of IgAN.

Cellular DNA repair cofactors affecting hepatitis B virus infection and replication

AIM： To investigate whether hepatitis B virus （HBV） infection activates DNA damage response and DNA repair cofactors inhibit HBV infection and replication. METHODS： Human hepatocyte cell line HL7702 was studied. Immunoblotting was performed to test the expression of ataxia telangiectasia-mutated （ATM）- Rad3-related protein （ATR）, p21 and the level of phosphorylation of Chkl, p53, H2AX, ATM in HBV-infected or non-infected-cells. Special short RNAi oligos was transfected to induce transient ATR knockdown in HL7702. ATR-ATN chemical inhibitors caffeine （CF） and theophylline （TP）, or Chkl inhibitor 7-hydroxystaurosporine （UCN01） was studied to determine whether they suppress cellular DNA damage response and NG132 inhibits proteasome. RESULTS： The ATR checkpoint pathway, responding to single-strand breaks in DNA, was activated in response to HBV infection. ATR knockdown cells decreased the HBV DNA yields, implying that HBV infection and replication could activate and exploit the activated DNA damage response. CF/TP or UCN01 reduced the HBV DNA yield by 70% and 80%, respectively. HBV abrogated the ATR-dependent DNA damage signaling pathway by degrading p21, and introduction of the p21 protein before HBV infection reduced the HBV DNA yield. Consistent with this result, p21 accumulation after NG132 treatment also sharply decreased the HBV DNA yield. CONCLUSION： HBV infection can be treated with therapeutic approaches targeting host cell proteins by inhibiting a cellular gene required for HBV replication or by restoring a response abrogated by HBV, thus providing a potential approach to the prevention and treatment of HBV infection.

Rapid quantification of hepatitis B virus DNA by real-time PCR using efficient TaqMan probe and extraction of virus DNA

AIM： To rapidly quantify hepatitis B virus （HBV） DNA by real-time PCR using efficient TaqMan probe and extraction methods of virus DNA. METHODS： Three standards were prepared by cloning PCR products which targeted S, C and X region of HBV genome into pGEM-T vector respectively. A pair of primers and matched TaqMan probe were selected by comparing the copy number and the Ct values of HBV serum samples derived from the three different standard curves using certain serum DNA. Then the efficiency of six HBV DNA extraction methods including guanidinium isothiocyanate, proteinase K, NaI, NaOH lysis, alkaline lysis and simple boiling was analyzed in sample A, B and C by real-time PCR. Meanwhile, 8 clinical HBV serum samples were quantified. RESULTS： The copy number of the same HBV serum sample originated from the standard curve of S, C and X regions was 5.7 × 10^4/mL, 6.3 × 10^2/mL and 1.6 × 10^3/ mL respectively. The relative Ct value was 26.6, 31.8 and 29.5 respectively. Therefore, primers and matched probe from S region were chosen for further optimization of six extraction methods. The copy number of HBV serum samples A, B and C was 3.49 × 10^9/mL, 2.08 × 10^6/mL and 4.40 × 10^7/mL respectively, the relative Ct value was 19.9, 30 and 26.2 in the method of NaOH lysis, which was the efficientest among six methods. Simple boiling showed a slightly lower efficiency than NaOH lysis. Guanidinium isothiocyanate, proteinase K and NaI displayed that the copy number of HBV serum sample A, B and C was around 10^S/mL, meanwhile the Ct value was about 30. Alkaline failed to quantify the copy number of three HBV serum samples. Standard deviation （SD） and coefficient variation （CV） were very low in all 8 clinical HBV serum samples, showing that quantification of HBV DNA in triplicate was reliable and accurate. CONCLUSION： Real-time PCR based on optimized primers and TaqMan probe from S region in combination with NaOH lysis is a simple, rapid and accurate method for quantification of HBV serum DNA.

Novel DNA vaccine based on hepatitis B virus core gene induces specific immune responses in Balb/c mice

AIM： To investigate the immunogenidty of a novel DNA vacoine, pSW3891/HBc, based on HBV core gene in Balb/c mice. METHODS： A novel DNA vaccine, pSW3891/HBc, encoding HBV core gene was constructed using a vector plasmid pSW3891. Balb/c mice were immunized with either pSW3891/HBc or empty vector DNA via gene gun. IgG anti-HBc responses in mouse sera were demonstrated by ELISA. Specific cytotoxicity of cytotoxic T lymphocytes （CTLs） of mice was quantitatively measured by lactate dehydrogenase release assay. RESULTS： HBcAg was expressed effectively in 293T cell line transiently transfected with pSW3891/HBc. Strong IgG anti-HBc responses were elicited in mice immunized with pSW3891/HBc. The end-point titers of anti-HBc reached the highest 1：97 200, 4 wk after the third immunization. The specific CTL killing with the highest specific lysis reached 73.25% at effector：target ratio of 20：1 in mice that received pSW3891/HBc DNA vaccine. CONCLUSION： pSW3891/HBc vaccination elicits specific anti-HBc response and induces HBc-specific CTL response in immunized Balb/c mice.

Combination of small interfering RNAs mediates greater suppression on hepatitis B virus cccDNA in HepG2.2.15 cells

AIM： To observe the inhibition of hepatitis B virus （HBV） replication and expression in HepG2.2.15 cells by combination of small interfering RNAs （siRNAs）. METHODS： Recombinant plasmid psiI-HBV was constructed and transfected into HepG2.2.15 cells. At 48 h, 72 h and 96 h after transfection, culture media were collected and cells were harvested for HBV replication assay. HBsAg and HBeAg in the cell culture medium were detected by enzyme-linked immunoadsorbent assay （ELISA）. Intracellular viral DNA and covalently closed circular DNA （cccDNA） were quantified by real-time polymerase chain reaction （PCR）. HBV viral mRNA was reverse transcribed and quantified by reverse-transcript PCR （RT-PCR）. RESULTS： siRNAs showed marked anti-HBV effects. siRNAs could specifically inhibit the expression of HBsAg and the replication of HBV DNA in a dosedependent manner. Furthermore, combination of siRNAs, compared with individual use of each siRNA, exerted a stronger inhibition on antigen expression and viral replication. More importantlycombination of siRNAs significantly suppressed HBV cccDNA amplification. CONCLUSION： Combination of siRNAs mediates a stronger inhibition on viral replication and antigenexpression in HepG2.2.15 cells, especially on cccDNA amplification.

Comparison of real-time polymerase chain reaction with the COBAS Amplicor test for quantitation of hepatitis B virus DNA in serum samples

AIM:To compare the clinical performance of a real-time PCR assay with the COBAS Amplicor Hepatitis B Virus (HBV) Monitor test for quantitation of HBV DNA in serum samples. METHODS: The reference sera of the Chinese National Institute for the Control of Pharmaceutical and Biological Products and the National Center for Clinical Laboratories of China, and 158 clinical serum samples were used in this study. The linearity, accuracy, reproducibility, assay time, and costs of the real-time PCR were evaluated and compared with those of the Cobas Amplicor test. RESULTS: The intra-assay and inter-assay variations of the real-time PCR ranged from 0.3% to 3.8% and 1.4% to 8.1%, respectively. The HBV DNA levels measured by the real-time PCR correlated very well with those obtained with the COBAS Amplicor test (r = 0.948). The real-time PCR HBV DNA kit was much cheaper and had a wider dynamic range. CONCLUSION: The real-time PCR assay is an excellent tool for monitoring of HBV DNA levels in patients with chronic hepatitis B.