Mapping of the hepatitis B virus attachment site by use of infection-inhibiting preS1 lipopeptides and tupaia hepatocytes

BACKGROUND & AIMS: Studies on the early steps in the life cycle of hepatitis B virus have been hampered by the lack of readily available target cells. In this study, we mapped a defined virus attachment site to primary hepatocytes that is essential for infection. METHODS: We used purified virus particles from human carrier plasma as an inoculum and primary cultures of tupaia hepatocytes as susceptible target cells and studied the inhibitory effect of amino-terminally acylated preS1-derived lipopeptides on infection interference. RESULTS: Infectivity of virus could be blocked efficiently in this system by amino-terminally acylated peptides containing amino acids 2-18 from the preS1 domain. The addition of amino acids 28-48 enhanced the inhibitory capacity, whereas amino acids 49-78 did not contribute to inhibition. Myristoylated preS1 peptides 2-48 bound strongly to tupaia hepatocytes but not to nonhepatic cells or rodent hepatocytes and thereby inhibited infection even at concentrations of 1 nmol/L completely. Particles consisting only of the small hepatitis B surface protein-the active component of current hepatitis B vaccines-did not bind at all to tupaia hepatocytes, but the addition of the preS1 domain to the particles allowed binding. CONCLUSIONS: The preS1 sequence 2-48 mediates attachment of the virus to its target cells, whereas the small surface protein seems to be involved in other steps. These findings indicate that the current subunit hepatitis B vaccines may be improved by the addition of distinct preS1 epitopes. Moreover, preS1 lipopeptides are promising candidates for specific antiviral therapy against hepatitis B infections.     

Expression of hepatitis B surface antigen subtypes in liver of patients with hepatocellular carcinoma; comparison of subtypes in serum and liver

ABSTRACT— To clarify the discrepancy in hepatitis B surface antigen (HBsAg) subtypes present in the serum and liver, as well as among hepatocytes, liver specimens which were resected from 37 HBsAg-positive patients with hepatocellular carcinoma (HCC) were examined. We evaluated HBsAg and the subtypic determinants of HBsAg and hepatitis B core antigen (HBcAg) using the peroxidase-antiperoxidase (PAP) staining method. Hepatitis B antigens were more frequently detected in small tumors (HBsAg in 67%, HBcAg in 40%) than in large ones (HBsAg in 36%, HBcAg in 14%). The prevalence of each subtypic determinant in the HBsAg positive non-tumorous vs. tumorous areas was 100% vs. 67% in a, 100% vs. 57% in d, 100% vs. not tested in y, 100% vs. 53% in r and 25% vs. 0% in w (a, d, y, r and w represent subtypic determinants). There was virtually no difference in a set of subtypic determinants between the serum and liver. However, there were some variations in a set of subtypic determinants among the hepatocytes. On the other hand, liver tissue of compound subtype adyr in serum contained both cells with a,d,r and with a,y,r as well as a few cells with a,d,y,r. These findings suggest that HBV genomes in hepatocytes of type B chronic liver disease may differ genetically among cells even in the same liver tissue.     

产妇血清表面抗原定量与乳汁中乙肝病毒载量的相关性分析

目的 探讨携带乙型肝炎病毒(HBV)的产妇血清表面抗原(HBsAg)含量与乳汁中HBV-DNA含量的相关性,并指导母乳喂养.方法 对140例产妇采用荧光定量PCR法测定乳汁中HBV-DNA和化学发光法测定表面抗原含量,并进行相关性分析.结果 A组乳汁HBV-DNA阳性组表面抗原含量为(58 183.2±39 147.8) IU/ml,B组HBV-DNA阴性组表面抗原含量为(1848.8±2458.3) IU/ml.A组血清中表面抗原含量比B组高,差异有统计学意义(P＜0.01),乳汁中HBV-DNA含量与血清中表面抗原含量呈正相关(r=0.799,P＜0.01).结论 慢性HBV感染孕产妇血清中乙肝表面抗原的定量的测定及检测其乳汁中HBV-DNA含量,对阻断母婴传播和预防家庭内水平传播及对HBV感染孕产妇的诊治和疗效评估有着重要意义,特别是为HBV感染产妇选择是否母乳喂养提供了指导依据.     

Prevention of perinatal hepatitis B transmission in Haimen City,China: Results of a community public health initiative

In regions where hepatitis B virus (HBV) is endemic, perinatal transmission is common. Infected newborns have a 90% chance of developing chronic HBV infection, and 1 in 4 will die prematurely from HBV-related liver disease. In 2010, the Hepatitis B Foundation and the Haimen City CDC launched the Gateway to Care campaign in Haimen City, China to improve awareness, prevention, and control of HBV infection citywide. The campaign included efforts to prevent perinatal HBV transmission by screening all pregnant women for hepatitis B surface antigen (HBsAg), following those who tested positive, and administering immunoprophylaxis to their newborns at birth. Of 5407 pregnant women screened, 185 were confirmed HBsAg-positive and followed until delivery. At age one, 175 babies were available for follow up testing. Of those, 137 tested negative for HBsAg and positive for antibodies to HBsAg, indicating protection. An additional 34 HBsAg-negative babies also tested negative for antibodies to HBsAg or had indeterminate test results, were considered to have had inadequate immune responses to the vaccine, and were given a booster dose. A higher prevalence of nonresponse to HBV vaccine was observed among babies born to hepatitis B e antigen (HBeAg)-positive mothers and mothers with high HBV DNA titers. The remaining 4 babies tested positive for HBsAg and negative for antibodies, indicative of active HBV infection. The mothers of all 4 had viral loads ≥8 × 10⁶ copies/ml in the third trimester. Although inadequate response or nonresponse to HBV vaccine was more common among babies born to HBeAg-positive and/or high viral load mothers, these risk factors did not completely predict nonresponsiveness. All babies born to HBV-infected mothers should be tested upon completion of the vaccine series to ascertain adequate protection. Some babies of HBeAg-positive mothers with high viral load may still become HBV infected despite timely immunoprophylaxis with HBV vaccine and HBIG.     

2006年新疆库尔勒市1 311名中学生HBsAg检测分析

为了解新疆库尔勒市在校学生乙型肝炎病毒携带情况,更好地采取预防为主和防治并举的措施,于2006年4月对库尔勒市某中学的在校学生进行了HBsAg检测。1对象与方法2006年4月对库尔勒市某中学在校中学生进行了HBsAg检测,共计1 311人,其中男生612人,女生699人。采用酶联免疫法检测Hb     

Occult infection with HBV intergenotypic A2/G recombinant following acute hepatitis B caused by an HBV/A2 isolate

Viral and host factors leading to occult hepatitis B virus (HBV) infection (OBI) are not fully understood. Whether HBV genotype may influence the occurrence and course of OBIs is unknown. Here, we describe the case of a patient infected with HBV genotype A2 who developed symptomatic acute hepatitis and did not seroconvert after loss of HBsAg and HBeAg. The acute phase of hepatitis B was followed by a period of more than 2 years during which the DNA of an intergenotypic HBV/A2/G recombinant was intermittently detected in serum.     

定量检测710例肝病患者HBsAg和H BeAg临床意义

目的：了解乙型肝炎与肝硬化患者表面抗原（HBsAg）与e抗原（HBeAg）定量变化规律,探讨分层次联合抗病毒治疗并争取满意效果的可行性。方法采用荧光磁微粒酶免法检测710例 HBV 相关肝病患者 HBsAg 和HBeAg,用SPSS19．0软件包进行统计学处理。结果 HBsAg＜0．2 IU/mL 61例,占8．5％;HBsAg＞0．2 IU/mL～＜100 IU/mL 为低水平 HBsAg组,55例,占7．7％;HBsAg ＞100 IU/mL～＜1000 IU/mL 为中等水平 HBsAg 组,142例,占20％;HBsAg 1000～5000 IU/mL为高水平 HBsAg 组,211例,占29．7％;HBsAg＞5000 IU/mL 为超高水平HBsAg组,241例,占33．9％;各型肝炎随年龄增大,HBsAg 定量值逐步下降,转阴高峰集中在46岁左右;HBeAg 阴性组（＜1．0 CI）453例,占63．8％;低水平 HBeAg阳性组（＞1．0 CI～＜10 CI）96例,占13．5％;中等量水平 HBeAg 阳性组（＞10 CI～＜100 CI）55例,占7．7％;高水平 HBeAg 阳性组（＞100 CI～＜500 CI）23例,占3．2％;超高水平HBeAg阳性组（＞500 CI）83例,占11．6％;从慢性 HBV携带者,慢性乙型肝炎,代偿期肝硬化到失代偿期肝硬化,年龄逐步增大,HBsAg和 HBeAg定量秩均值逐步下降,卡方检验有显著性差异。结论 HBsAg 和 HBeAg 定量随年龄增加与病情发展逐步下降,根据 HBsAg,HBeAg 和 HBV DNA定量进行分层次联合抗病毒治疗可争取较满意效果。     

Long‐term hepatitis B surface antigen (HBsAg) kinetics during entecavir treatment in Korean patients—Functional cure unlikely

The aim of this study was to investigate the on‐treatment kinetics of quantitative HBsAg during entecavir therapy to predict the treatment period needed to achieve functional cure. From a cohort of 1009 CHB treatment‐naïve patients who were started on entecavir, the kinetics of quantitative HBsAg decline was assessed in 410 patients by a linear mixed model. The difference in the kinetics of quantitative HBsAg was determined based on the HBeAg positivity, HBeAg seroclearance and presence of baseline liver cirrhosis. Among the 410 patients, 213 patients (52.0%) were HBeAg‐positive and 217 patients (66.1%) were male with a median age of 48 years. During a median follow‐up of 53.5 months, the quantitative HBsAg level showed a slow but consistent decrease. The expected log qHBsAg levels as a function of time during entecavir treatment in HBeAg(+) and HBeAg(?) patients were 3.4773‐0.0039 × Months and 3.1853‐0.0036 × Months, respectively. The estimated time to clearance of quantitative HBsAg in our study was greater than 74.1 years in HBeAg‐positive patients and 73.5 years in HBeAg‐negative patients. The calculated time to achieve functional cure is lifelong without regard to HBeAg seroclearance or presence of liver cirrhosis. The mathematical modelling from a long‐term follow‐up of chronic hepatitis B patients on entecavir shows that HBsAg clearance requires decades of treatment. Thus, lifelong therapy is inevitable in entecavir‐treated patients to achieve functional cure.     

The efficacy of hepatitis B treatments in achieving HBsAg seroclearance: A systematic review and meta‐analysis

Current therapies for chronic hepatitis B (CHB) include nucleos(t)ide analogues (NAs) and interferon (IFN), but their relative efficacy as monotherapy or in combination has not been examined systematically for HBsAg loss (functional cure). Hence, we systematically reviewed the evidence for HBsAg loss in CHB patients treated with IFN, NA or the combination. We searched PubMed, EMBASE and abstracts from EASL, Asia Pacific Association for study of the Liver and American Association for the Study of Liver Disease for randomized controlled trials of CHB patients, comparing NA, IFN or the combination. The Cochrane Risk of Bias tool v2.0 and GRADE method were used. Analyses were stratified by NA genetic barrier, cirrhosis, type of combination therapy, HBeAg, treatment naivety, IFN dosage/duration and outcome duration. Sensitivity analysis was performed for selected strata, and HBsAg loss was measured at the end‐of‐study (EOS), end‐of‐treatment (EOT) or end‐of‐follow‐up (EOF). Effects were reported as risk differences (RD) with 95% confidence intervals (CI) using a random‐effects model. Forty‐five studies were included, all with low risk of bias. For HBsAg loss at EOS, when comparing combination vs IFN, RD = 1%, 95%CI‐1%, 2%; combination vs NA, RD = 5%, 95%CI 3%,7%; IFN vs NA, RD = 3%, 95%CI 2%,5%. Subgroup analysis showed a significant effect of standard IFN dose vs nonstandard; IFN duration ≥48 weeks vs <48 weeks, and loss of efficacy >2 years of follow‐up. Similar findings were seen in HBsAg seroconversion, but only three studies reported HBsAg seroreversion. In conclusion, IFN monotherapy/combination had a small but significant increase in HBsAg loss over NA, associated with standard dose of IFN and ≥48 weeks of therapy, although this effect faded over time.