Reconstructing the Complex Evolutionary History of Hepatitis B Virus

A detailed analysis of the evolutionary history of hepatitis B virus (HBV) was undertaken using 39 mammalian hepadnaviruses for which complete genome sequences were available, including representatives of all six human genotypes, as well as a large sample of small S gene sequences. Phylogenetic trees of these data were ambiguous, supporting no single place of origin for HBV, and depended heavily on the underlying model of DNA substitution. In some instances genotype F, predominant in the Americas, was the first to diverge, suggesting that the virus arose in the New World. In other trees, however, sequences from genotype B, prevalent in East Asia, were the most divergent. An attempt was also made to determine the rate of nucleotide substitution in the C open reading frame and then to date the origin of HBV. However, no relationship between time and number of substitutions was found in two independent data sets, indicating that a reliable molecular clock does not exist for these data. Both the pattern and the rate of nucleotide substitution are therefore complex phenomena in HBV and hinder any attempt to reconstruct the past spread of this virus. Received: 5 December 1998 / Accepted: 23 February 1999     

Hepatitis B and ratio of masculinity]

Among families of blood donors from Languedoc, found to be chronic carriers of HBs antigens, the masculinity ratio of the siblings (number of boys compared to number of girls) calculated on 303 individuals is significantly higher (1,32) than that of the general population (1,05). This rise is still increased when considering only the families where the viral infection is present in the mother (1,73), whereas it is very low when in the father (1,09).     

Hepatitis B among drug addicts]

In the years 1980-1988 twenty five drug addicts were identified among 1841 patients hospitalized for acute hepatitis in the Dep. of Hepatology at the Institute of Infectious and Parasitic Diseases in Warsaw. 15 drug addicts had hepatitis B and 10 had hepatitis A. It was found, that the course of acute type B hepatitis was milder in drug addicts, than among control group consisting of non-addicts.     

Hepatitis B virus infection in alcoholics]

Chromosomal analysis has been carried out in 4 patients with the symptoms of hepatic coma. An analysis included lymphocytes cultured from peripheral blood. Chromosomal disorders have been assessed with two techniques: structural chromosomal aberrations test, and sister chromatid exchange (SCE) test. It has been shown that the extend of chromosomal damage in the form of the gaps, breaks, acentric chromosomes as well as the presence of ring and dicentric chromosomes, and micronuclear cells have been higher in the examined patients. Such changes may evidence DNA repair disorders, and the presence of micronuclear forms may seem an unfavourable prognosis.     

Biochemical typing as a method of differentiating group B streptococcus]

In epidemiological studies on the group B streptococcus the serological typing is used. The paper present the results of a study on usefulness of biochemical typing for differentiation of the group B streptococcus. For that purpose, 210 strains descended from colonized infants and pregnant women were put to typing with both of mentioned methods. We showed that each of the method distinguishes similar number of biotypes and serotypes. However, ought to be marked that significant number of strains (93.8%) belonged to the three out of eight biochemical types. Similar results were achieved in serological typing, three of the most numerous serotypes contained 81.4% strains. Analysis of the relationship between serological and biochemical types did not reveal statistical association because the strains belonged to various serotypes. Obtained results show that both methods of typing--biochemical and serological, have similar value in differentiation of the strains. The method of biochemical typing is quite simple and can be used in laboratory conditions.     

Effects of Entecavir on Hepatitis B Virus Covalently Closed Circular DNA in Hepatitis B e Antigen-Positive Patients with Hepatitis B

The aim of this study was to assess the effect of 48-week entecavir therapy on serum and intrahepatic hepatitis B virus, covalently closed circular DNA (HBV cccDNA) levels in hepatitis B e antigen (HBeAg)-positive patients. A total of 120 patients with HBeAg-positive chronic hepatitis were treated with entecavir for 48 weeks. Serum HBV markers, total HBV DNA, and HBV cccDNA levels were measured at baseline and week 48. Biopsies from 20 patients were available for both intrahepatic total HBV DNA and cccDNA testing at these timepoints. HBV cccDNA levels were decreased from a median level of 5.1×10⁶ copies/mL at baseline to a median level of 2.4×10³ copies/mL at week 48. Reduction magnitudes of HBV cccDNA in patients with normalized alanine aminotransferase levels and those undergoing HBeAg seroconversion were significantly greater than those in alanine aminotransferase-abnormal and HBeAg positive patients. Intrahepatic HBV cccDNA was decreased significantly after 48 weeks of treatment, but could not be eradicated. In conclusion, treatment of HBeAg-positive hepatitis B patients with entecavir for 48 weeks decreased serum and intrahepatic HBV cccDNA significantly, and the magnitude of HBV cccDNA reduction was related to total HBV DNA decrease, alanine aminotransferase normalization, and HBeAg seroconversion.     

抗—HBe阳性慢性乙肝临床研究

报告34例抗-HRe阳性慢性乙型肝炎(CHB),占同期住院抗-HBe阳性者的38％。这些患者于3—9年内肝炎再活动2—4次,累计80次。肝炎再活动时的临床表现及肝功损害与同期住院的HBeAg阳性CHB相似,但抗-HBe阳性CHB者肝硬化及肝癌发生比例显著高于HBeAg阳性者(P<0.05)。血清乙肝病毒标志(HBVM)检测发现,80次肝炎再活动中,38次(47.5％)有HBV活跃复制,提示HBV活跃复制是部分抗-HBe阳性CHB肝炎再活动的根本原因,另一部要考虑是其它肝炎病毒重叠感染的结果。     

Familial Clustering of Hepatitis B Antigen: A Study in Relatives of Patients with Liver Diseases and Hepatitis B Antigenaemia

Twelve of the 100 family contacts of 29 patients with transient and persistent hepatitis B antigenaemia were found to be positive for hepatitis B antigen (HBAg). No relation was found between familial clustering and the nature of liver disease or the duration of antigenaemia in the index cases.Eight affected relatives were apparently healthy carriers of HBAG, one had cirrhosis, and three (in the same family) developed acute viral hepatitis.The absence of parenteral exposure in the HBA,-positive family contacts and the identity in antigenic determinants d or y with those of the index cases, suggest a non-parenteral spread of HBAg in families of patients with HBAg-associated liver diseases.     

The Impact of Vaccination and Antiviral Therapy on Hepatitis B and Hepatitis D Epidemiology

The major cause of liver cancer around the globe is hepatitis B virus (HBV), which also contributes to a large number of deaths due to liver failure alone. Hepatitis delta virus (HDV) is as potentially alarming as HBV since life threatening cases are 10 times more likely with HBV-HDV dual infection compared to HBV monoinfection. So far, there is no established effective treatment against HDV and the only preventive action suggested by the World Health Organization is to introduce HBV vaccination for children immediately after birth (newborns) and thus reduce the available pool for HDV infection. Here the main objective is to understand the complex dynamics of HBV-HDV infection in a human population that can inform public health policy makers on the level of different preventive measures required to eliminate HBV and HDV infections. Model simulations suggest that HBV vertical transmission and HBV vaccination rates for newborns are instrumental in determining HBV and HDV prevalence. A decrease in HBV prevalence is observed as vaccination coverage increases and it is possible to eradicate both HBV and HDV using high vaccination coverage of ≥80% in the long term. We further found that HDV presence results in lower HBV prevalence. An application of our model to China revealed that vaccinating every newborn in China will further prevent 1.69 million new infections by 2028 as compared to the current 90% vaccination coverage. Although, higher vaccination coverage of newborns should eliminate both HBV and HDV over a long time period, any short term strategy to eradicate HDV must include additional preventive measures such as HBV adult vaccination. Implementation of HBV adult vaccination programs at a rate of 10% per year over 15 years will further prevent 39 thousand new HDV infections in China by 2028 as compared to HBV vaccination programs solely for newborns.     

慢性乙型肝炎抗病毒治疗研究进展

乙肝病毒的慢性感染是肝纤维化、肝细胞癌的重要病因,积极有效地抗病毒治疗,可显著改善HBV感染者的生活质量。干扰素、核苷（酸）类药物的抗乙肝病毒疗效已得到全球公认,本文就上述两类药物的研究进展进行综述。     

乙肝病毒PreSl片段与乙肝表面抗原羧端的融合表达

我们利用聚合酶链反应法（ＰＣＲ）得到了编码乙肝病毒肝细胞受体结合位点ＰｒｅＳｌ（２１￣４７）的基因片段,并将它分别融合到Ｓ基因中相应于第１７５,１８８和２２３位氨基酸残基处。所得到的融合基因插入痘苗病毒表达载体ｐＧＪＰ－５后,在哺乳动物细胞ＣＶ－１中进行了暂时表达,对融合蛋白的表达、分泌和抗原性的研究表明,３种融合基因均能表达具有Ｓ和ＰｒｅＳｌ双重抗原性的融合蛋白,但融合位点对表达水平和分泌性质有     

乙肝相关性肾炎治疗的研究进展

乙型肝炎病毒相关性肾炎(HBV-GN)是临床常见的继发性肾脏病,它的治疗尚无明确、统一的原则可循.目前国内外对现有的治疗HBV-GN药物的疗效,进行了多个大规模随机、对照的临床研究并对其进行相关系统评价及Mate分析,以期对HBV-GN的治疗选择更合适的治疗药物,减少治疗上的盲目性,提高治疗HBV的临床疗效,延缓HBV-GN进展到终末期肾衰竭的进程.本文以国内外研究文献为基础,对文献资料进行分析、归纳和总结,综述乙肝相关性肾炎治疗的研究现状.现已有多种药物被用于治疗乙肝相关性肾炎,但迄今为止最佳的治疗方案尚无定论.综合现有研究发现由于单独使用一种抗病毒药物或免疫抑制剂治疗效果有限且易复发,因此联合或序贯使用两种或两种以上药物,抑制病毒更快,耐药发生较少,肾脏损伤进展较慢,临床结局较好.     

Impact of Genetic Heterogeneity in Polymerase of Hepatitis B Virus on Dynamics of Viral Load and Hepatitis B Progression

Objective

The hepatitis B virus (HBV)-polymerase region overlaps pre-S/S genes with high epitope density and plays an essential role in viral replication. We investigated whether genetic variation in the polymerase region determined long-term dynamics of viral load and the risk of hepatitis B progression in a population-based cohort study.

Methods

We sequenced the HBV-polymerase region using baseline plasma from treatment-naïve individuals with HBV-DNA levels≥1000 copies/mL in a longitudinal viral-load study of participants with chronic HBV infection followed-up for 17 years, and obtained sequences from 575 participants (80% with HBV genotype Ba and 17% with Ce).

Results

Patterns of viral sequence diversity across phases (i.e., immune-tolerant, immune-clearance, non/low replicative, and hepatitis B e antigen (HBeAg)-negative hepatitis phases) of HBV-infection, which were associated with viral and clinical features at baseline and during follow-up, were similar between HBV genotypes, despite greater diversity for genotype Ce vs. Ba. Irrespective of genotypes, however, HBeAg-negative participants had 1.5-to-2-fold higher levels of sequence diversity than HBeAg-positive participants (P<0.0001). Furthermore, levels of viral genetic divergence from the population consensus sequence, estimated by numbers of nucleotide substitutions, were inversely associated with long-term viral load even in HBeAg-negative participants. A mixed model developed through analysis of the entire HBV-polymerase region identified 153 viral load-associated single nucleotide polymorphisms in overall and 136 in HBeAg-negative participants, with distinct profiles between HBV genotypes. These polymorphisms were most evident at sites within or flanking T-cell epitopes. Seven polymorphisms revealed associations with both enhanced viral load and a more than 4-fold increased risk of hepatocellular carcinoma and/or liver cirrhosis.

Conclusions

The data highlight a role of viral genetic divergence in the natural course of HBV-infection. Interindividual differences in the long-term dynamics of viral load is not only associated with accumulation of mutations in HBV-polymerase region, but differences in specific viral polymorphisms which differ between genotypes.     

Hepatocellular Carcinoma in The Gambia and the role of Hepatitis B and Hepatitis C

Objectives

Hepatocellular Carcinoma is the commonest form of cancer in The Gambia, and although Hepatitis B and Hepatitis C are known risk factors, accurate baseline data on Hepatitis B and Hepatitis C distribution in the region are limited. Similarly data including information on the involvement of the viruses in HCC remains unknown. The current study was undertaken to estimate the risk of HCC in relation to HCV and HBV in The Gambia.

Methods

Thirteen patients with histological proven history of HCC and 39 healthy controls were enrolled in the study. Each subject blood was screened individually for anti-HCV using ORTHO HCV 3.0 ELISA test system (Ortho-Clinical Diagnostics, Inc, U.S.A) and for HBsAg using QUADRATECH CHECK 4-HBs one step generation hepatitis B surface antigen test kit (VEDALAB, France) following the manufacturers instructions.

Results

HBsAg and anti-HCV was detected in 38.5 %(5/13) and 7.7% (1/39) of the persons with a history of HCC respectively. HBsAg but not anti-HCV was detected in 12.8% (5/39 of the case control subjects. HBsAg and HCV rates among the HCC patients were higher in men than women. Rates were highest in patients 48 years and above (37.5%; 3/8). No patient was found with anti-HCV and anti-HBV.

Conclusion

These results indicate that the involvement of HBV and HCV in HCC in the country is in a ratio of 5:1 and that these two viruses might be independently involved in the pathogenesis of the disease. The study revealed a statistically significant association (p = 0.04) between HBsAg and HCC patients.The results also indicate that up to 50% of HCC cases in the country may be due to non viral factors and calls for further studies in this regard. These findings call for provision of diagnostic facilities for these viruses in hospitals and for their routine screening in blood banks while intervention programmes should be put in place.

     

Epidemic History and Evolutionary Dynamics of Hepatitis B Virus Infection in Two Remote Communities in Rural Nigeria

Background

In Nigeria, hepatitis B virus (HBV) infection has reached hyperendemic levels and its nature and origin have been described as a puzzle. In this study, we investigated the molecular epidemiology and epidemic history of HBV infection in two semi-isolated rural communities in North/Central Nigeria. It was expected that only a few, if any, HBV strains could have been introduced and effectively transmitted among these residents, reflecting limited contacts of these communities with the general population in the country.

Methods and Findings

Despite remoteness and isolation, ∼11% of the entire population in these communities was HBV-DNA seropositive. Analyses of the S-gene sequences obtained from 55 HBV-seropositive individuals showed the circulation of 37 distinct HBV variants. These HBV isolates belong predominantly to genotype E (HBV/E) (n = 53, 96.4%), with only 2 classified as sub-genotype A3 (HBV/A3). Phylogenetic analysis showed extensive intermixing between HBV/E variants identified in these communities and different countries in Africa. Quasispecies analysis of 22 HBV/E strains using end-point limiting-dilution real-time PCR, sequencing and median joining networks showed extensive intra-host heterogeneity and inter-host variant sharing. To investigate events that resulted in such remarkable HBV/E diversity, HBV full-size genome sequences were obtained from 47 HBV/E infected persons and P gene was subjected to Bayesian coalescent analysis. The time to the most recent common ancestor (tMRCA) for these HBV/E variants was estimated to be year 1952 (95% highest posterior density (95% HPD): 1927–1970). Using additional HBV/E sequences from other African countries, the tMRCA was estimated to be year 1948 (95% HPD: 1924–1966), indicating that HBV/E in these remote communities has a similar time of origin with multiple HBV/E variants broadly circulating in West/Central Africa. Phylogenetic analysis and statistical neutrality tests suggested rapid HBV/E population expansion. Additionally, skyline plot analysis showed an increase in the size of the HBV/E-infected population over the last ∼30–40 years.

Conclusions

Our data suggest a massive introduction and relatively recent HBV/E expansion in the human population in Africa. Collectively, these data show a significant shift in the HBV/E epidemic dynamics in Africa over the last century.     

A Mechanism To Explain the Selection of the Hepatitis e Antigen-Negative Mutant during Chronic Hepatitis B Virus Infection

Hepatitis B virus (HBV) expresses two structural forms of the nucleoprotein, the intracellular nucleocapsid (hepatitis core antigen [HBcAg]) and the secreted nonparticulate form (hepatitis e antigen [HBeAg]). The aim of this study was to evaluate the ability of HBcAg- and HBeAg-specific genetic immunogens to induce HBc/HBeAg-specific CD4⁺/CD8⁺ T-cell immune responses and the potential to induce liver injury in HBV-transgenic (Tg) mice. Both the HBcAg- and HBeAg-specific plasmids primed comparable immune responses. Both CD4⁺ and CD8⁺ T cells were important for priming/effector functions of HBc/HBeAg-specific cytotoxic T-lymphocyte (CTL) responses. However, a unique two-step immunization protocol was necessary to elicit maximal CTL priming. Genetic vaccination did not prime CTLs in HBe- or HBc/HBeAg-dbl-Tg mice but elicited a weak CTL response in HBcAg-Tg mice. When HBc/HBeAg-specific CTLs were adoptively transferred into HBc-, HBe-, and HBc/HBeAg-dbl-Tg mice, the durations of the liver injury and inflammation were significantly greater in HBeAg-Tg recipient mice than in HBcAg-Tg mice. Importantly, liver injury in HBc/HBeAg-dbl-Tg mice was similar to the injury observed in HBeAg-Tg mice. Loss of HBeAg synthesis commonly occurs during chronic HBV infection; however, the mechanism of selection of HBeAg-negative variants is unknown. The finding that hepatocytes expressing wild-type HBV (containing both HBcAg and HBeAg) are more susceptible to CTL-mediated clearance than hepatocytes expressing only HBcAg suggest that the HBeAg-negative variant may have a selective advantage over wild-type HBV within the livers of patients with chronic infection during an immune response and may represent a CTL escape mutant.