乙型肝炎病毒基因型与病毒复制的关系

检测慢性乙型肝炎患者血清乙型肝炎病毒(HBV)基因型和病毒载量(HBV-DNA定量),探讨它们之间的关系。用微板核酸杂交-ELISA方法对HBV进行基因分型,用PCR荧光定量检测血清HBV-DNA水平,共318例。检测到HBV B型111例(35％);C型128(40％);混合型(B+C,C+D,B+C+D)45例(14％);D型2例;F型2例;未分型30例(9.4％);没有发现A、E型。结果发现,C型和混合型HBV的血清DNA水平高于B型(1.14×107vs2.2×107vsl.60×106拷贝/ml,P<0.05);而混合型HBV的血清DNA水平与C型无差别(P=0.127)。研究提示,我国HBV以B,C两基因型为主,HBV基因型可能是影响HBV复制的重要因素之一。     

Clinicopathological differences between hepatitis B viral genotype B- and C-related resectable hepatocellular carcinoma

Clinical and pathogenic differences exist between hepatitis B viral (HBV) genotypes B and C, and genotype C has a higher risk of hepatocellular carcinoma (HCC) development than genotype B. The aim of this study was to investigate whether HBV genotypes B and C influence the clinicopathological features of patients with resectable HCC. Stored serum samples from 193 patients with resectable HBV-related HCC were tested for HBV genotypes by a molecular method. Of 193 patients undergoing resection of HCC, 107 (55%) and 86 (45%) were infected with genotypes B and C, respectively. Compared with genotype C patients, genotype B patients were less likely to be associated with liver cirrhosis (33%vs 51%, P = 0.01). Pathologically, genotype B patients had a higher rate of solitary tumour (94%vs 86%, P = 0.048) and more satellite nodules (22%vs 12%, P = 0.05) than genotype C patients. Our results indicate that genotype B-related HCC is less associated with liver cirrhosis and has a higher frequency of solitary tumour as well as more satellite nodules than genotype C-related HCC. These characteristics may contribute to the recurrence patterns and prognosis of HBV-related HCC in patients with genotype B or C infection.     

Distribution and characteristics of hepatitis B virus genotype C subgenotypes in China

Genetic diversity within the same hepatitis B virus (HBV) genotype indicates the presence of several subgenotypes. We have found that genotype C is the most common in China, and this study aimed to determine the geographical distribution and characteristics of HBV-C subgenotypes in the country. A cohort of 534 patients with chronic HBV genotype C infection, collected across China, was analysed by nucleotide sequencing or polymerase chain reaction-restriction fragment length polymorphism. HBV-C1/Cs (n = 112, 21%) and HBV-C2/Ce (n = 397, 74%) were the most common HBV-C subgenotypes and showed different geographical distribution in China. No significant differences were found between patients infected with HBV-C1 and HBV-C2 when comparing liver function tests, hepatitis B e antigen positive rate and clinical manifestations. We identified two other types of HBV-C provisionally designated as HBV-CD1 and HBV-CD2, which have particular virological features and clustered in one geographic area. These two types of C/D hybrids have emerged through recombination with genotype D and encode serotype ayw2 hepatitis B surface antigen. In conclusion, there are at least four subtypes of HBV genotype C: subgenotypes C1, C2 and two types of C/D recombinants CD1 and CD2 in China, which have a distinct geographic distribution. Whether HBV-C subgenotypes differ in their impact on liver disease progression requires prospective studies.     

Incidence of development of hepatocellular carcinoma in Japanese patients infected with hepatitis B virus is equivalent between genotype B and C in long term

Hepatitis B virus (HBV) genotypes B (HBV/B) and C (HBV/C) are the most prevalent genotypes among Japanese patients with hepatitis. Reportedly, HBV/C infection has been associated with more severe disease progression, manifesting as developing cirrhosis and hepatocellular carcinoma (HCC), than HBV/B infection. However, no long‐term studies have examined the development of HCC in HBV/B‐infected patients in Japan. The aims of our study were to compare the incidence of HCC in HBV/B‐ or HBV/C‐infected patients. A total of 241 patients were followed up among 295 hepatitis B surface antigen (HBsAg)‐positive carriers. Genotypes of HBV were A in 1% (4/295), B in 61% (179/295), C in 37% (110/295) and D in 1% (2/295) patients, and 96% of HBV/B were infected with subgenotype Bj. The mean age at HCC diagnosis was significantly higher in HBV/B than in HBV/C (67.0 ± 10.0 vs 57.7 ± 8.0 years, P < 0.001). The value of FIB‐4 index was significantly higher in HBV/B than in HBV/C (P < 0.01). The rate of HCC was higher in HBV/C than in HBV/B, and a significant difference was observed until the 20‐year observation period (P = 0.048). However, thereafter, HCC associated with HBV/B increased, and no significant difference was observed between HBV/B and HBV/C. HCC development was consistently observed even in HBV/B infection, especially among elderly patients with advanced fibrosis compared with HBV/C. HBV/B‐infected patients developed HCC later in life, and in the long term, we found no differences in incidence of HCC development rates between these two genotypes.     

Mechanism of the dependence of hepatitis B virus genotype G on co‐infection with other genotypes for viral replication

Hepatitis B virus (HBV) is classified into several genotypes. Genotype G (HBV/G) is characterised by worldwide dispersion, low intragenotypic diversity and a peculiar sequence of the precore and core region (stop codon and 36‐nucleotide insertion). As a rule, HBV/G is detected in co‐infection with another genotype, most frequently HBV/A2. In a previous in vivo study, viral replication of HBV/G was significantly enhanced by co‐infection with HBV/A2. However, the mechanism by which co‐infection with HBV/A2 enhances HBV/G replication is not fully understood. In this study, we employed 1.24‐fold HBV/A2 clones that selectively expressed each viral protein and revealed that the core protein expressing construct significantly enhanced the replication of HBV/G in Huh7 cells. The introduction of the HBV/A2 core promoter or core protein or both genomic regions into the HBV/G genome showed that both the core promoter and core protein are required for efficient HBV/G replication. The effect of genotype on the interaction between foreign core protein and HBV/G showed that HBV/A2 was the strongest enhancer of HBV/G replication. Furthermore, Western blot analysis of Dane particles isolated from cultures of Huh7 cells co‐transfected by HBV/G and a cytomegalovirus (CMV) promoter–driven HBV/A2 core protein expression construct indicated that HBV/G employed HBV/A2 core protein during particle assembly. In conclusion, HBV/G could take advantage of core proteins from other genotypes during co‐infection to replicate efficiently and to effectively package HBV DNA into virions.     

Chronic hepatitis B: early viral suppression and long‐term outcomes of therapy with oral nucleos(t)ides

Summary. Chronic hepatitis B is a serious health problem worldwide with a substantial minority of patients experiencing premature death due to end‐stage liver disease and/or hepatocellular carcinoma. Antiviral therapy may help prevent complications of chronic hepatitis B, and seven agents are currently approved in many countries. Of these agents, five are nucleos(t)ide analogs that all have a risk of antiviral drug resistance with long‐term use. Efforts have been made in the recent years to prevent or to reduce the risk of viral resistance in patients treated with oral nucleos(t)ides as the majority of these patients will require therapy for 3–5 years or longer. One approach is to identify patients who would most likely develop antiviral resistance on long‐term therapy using predictors obtainable early in the course of treatment, when intervention with new or additional therapy can be instituted. The most important predictors of treatment outcomes are serum HBV DNA levels at baseline and during the first 6 months of therapy. The purpose of this synopsis is to review the recent literature regarding the importance of serum HBV DNA levels in association with treatment outcomes in chronic hepatitis B, particularly the association of complete viral suppression early in the course of oral therapy with long‐term treatment outcomes, particularly the incidence of antiviral drug resistance.     

Long‐term RNA interference and its application to hepatitis B virus

RNA interference (RNAi) is an ancient defensive mechanism in eukaryotes to control gene expressing and defend their genomes from foreign invaders. It refers to the phenomenon that double‐stranded RNA results in the sequence‐specific silencing of target gene expression. Although it was documented in a relatively short time ago, intensive research has facilitated making its mechanism clear. Researchers have found that it was a powerful tool for analyzing the functions of genes and treating tumors, infectious diseases and genetic abnormalities that are associated with a dominant gene defect. However, delivery in vivo, low blood stability and poor intracellular uptake present significant challenges for the development of RNAi reagents in clinical use. Thus, long‐term inducible RNAi was designed. There are hundreds of millions of hepatitis B virus (HBV) carriers in the world at present, a portion of whom will lose their lives after several years due to chronic complications such as cirrhosis, hepatocellular carcinomas or both. Although a preventive vaccine is now available, the present therapeutic options for chronically infected patients are limited and of low efficiency. Admittedly, to date most RNAi experiments have been done in vitro, but it is hoped that they may be developed into a therapeutic strategy for HBV in the near future. In this article the principles and construction of long‐term RNA are discussed. Its therapeutic potentiality and attention to the potential hazards will also outlined. We conclude that this ancient defensive mechanism can be recruited as a powerful weapon in the fight against HBV.     

Longitudinal evaluation of viral interactions in treated HIV-hepatitis B co-infected patients with additional hepatitis C and D virus

Summary  Virological interactions of hepatitis B (HBV), hepatitis C (HCV) and hepatitis D (HDV) viruses in HIV-infected patients have been poorly characterized especially under treatment influences. Undetection rates of hepatitis viruses were longitudinally analyzed in a 3-year cohort of 308 HIV–HBV co-infected patients and compared using Generalized Estimating Equation models adjusted for age, HIV-RNA, CD4 cell-count and antiviral treatment. Chronic hepatitis co-infection in HIV-infected patients (age years, SD) was: 265 HBV (40.7, 8.2); 19 HBV–HCV (39.7, 4.1); 12 HBV–HDV (35.2, 9.9); 12 HBV–HCV–HDV (39.2, 5.2). At inclusion, treatment with lamivudine/tenofovir was not significantly different between co-infection groups. HBV suppression was significantly associated with HDV (aOR = 3.85, 95%CI 1.13–13.10, P  =   0.03) and HCV tri-infection (aOR = 2.65, 95%CI 1.03–6.81, P  =   0.04), but marginally associated with HIV–HBV–HCV–HDV (aOR = 2.32, 95%CI 0.94–5.74, P  =   0.07). In quad-infection, lower HDV-undetectability ( vs HIV–HBV–HDV, P  =   0.2) and higher HCV-undetectability ( vs HIV–HBV–HCV, P  =   0.1) were demonstrated. The degree of HBV suppression varied between visits and co-infection groups [range of aOR during follow-up ( vs HIV–HBV co-infection): HIV–HBV–HCV = 2.23–5.67, HIV–HBV–HDV = 1.53–15.17]. In treated co-infected patients, HDV expressed continuous suppression over HCV- and HBV-replications. Peaks and rebounds from undetectable hepatitis B, C and/or D viremia warrant closer follow-up in this patient population. HDV-replication was uncontrolled even with antiviral treatment.     

Highly active antiretroviral therapy improved persistent lamivudine‐resistant viremia in acute hepatitis B virus genotype Ae infection with coinfection of human immunodeficiency virus

A 57‐year‐old man developed acute hepatitis B virus (AHB), caused by HBV genotype Ae. Lamivudine (LAM) therapy was started at 8 months after the disease onset, because the infection was persistent, but not self‐limited. Despite LAM therapy, the hepatitis became chronic. Further, virological breakthrough developed due to the emergence of LAM‐resistant YMDD mutants at 11 months after LAM therapy. Adefovir dipivoxil (ADV) was combined with LAM against breakthrough hepatitis at 28 months after LAM therapy. Sequential genetic analysis revealed that rtL217R, a mutation potentially diminishing the ADV efficacy, was detected before and after the combination therapy. During the follow‐up period, the patient unexpectedly turned out coinfected with human immunodeficiency virus (HIV) by measuring anti‐HIV‐1 antibody. At that time, LAM‐resistant HIV mutation, M184V, had been already detected. We switched from the combination therapy with LAM plus ADV to highly active antiretroviral therapy (HAART), which included tenofovir disoproxil fumarate. HAART drastically improved LAM‐resistant viremia and breakthrough hepatitis as well as HIV viremia and CD4 counts. Even in Japan, HBV genotype and HIV coinfection should be determined early in the treatment of AHB, and early induction of nucleotide analogs should be taken into consideration, because the proportion of AHB patients with HBV genotype A and the number of patients horizontally coinfected with HBV and HIV are increasing.     

Long‐term observation on hepatitis B surface antigen seroclearance in therapy experienced HIV/HBV co‐infected Chinese

The aim of this retrospective study was to observe hepatitis B surface antigen (HBsAg) seroclearance and explore predictors of HBsAg loss in HIV/HBV‐co‐infected patients receiving long‐term lamivudine or both tenofovir and lamivudine containing therapies. Quantification of HBsAg, hepatitis B e antigen and HBV DNA before and after initiation of HBV‐active antiretroviral therapy in a total of 268 HIV/HBV‐co‐infected patients started treatment between 2005 and 2017 were performed. Over a median of 65.63 months of follow‐up, 10 (3.7%) were observed HBsAg loss and the quantification of HBsAg in 7 (2.6%) patients were less than 50 IU/mL. With the prolongation of antiretroviral therapy duration time, the rates of HBsAg seroclearance tended to increase gradually, rising from 1.8% (3/163) during 2‐4 years treatment to 29.4% (10/34) after antiretroviral therapy for up to 10 years. Lower baseline qHBsAg and HBV DNA levels and strong 12‐month declines in qHBsAg were significantly associated with HBsAg seroclearance. The event of HBsAg seroclearance is uncommon among Chinese individuals with HIV/HBV co‐infection who have been treated with anti‐HBV containing antiretroviral therapy, and lifelong therapy for HBV is needed for HIV/HBV co‐infected patients. Baseline qHBsAg and HBV DNA levels and qHBsAg decline rate were predictors for HBsAg seroclearance.     

十堰地区乙肝病毒基因型分布及其临床意义

目的:了解十堰地区乙肝病毒基因型分布情况以及基因型与临床特征的关系,探讨其临床意义。方法:采用型特异性引物巢式PCR方法对本地区244例乙型肝炎患者进行基因型检测,同时对部分PCR产物进行测序,确定其基因型。结果:在244例乙型肝炎患者中,B型165例(67.62%)、BC混合型74例(30.33%)、C型5例(2.05%),未发现A、D、E、F型;AsC中,B型36例,占76.60%;HF、AHB、HCC中B基因型占绝对优势,分别为95.96%、100%、81.82%,显著高于LC的57.69%和CHB的60.00%,其中HF与LC、CHB之间差异显著(P<0.05,P<0.01);CHB中BC混合型51例(37.38%),与AsC中10例(21.28%)比较有统计学意义(P<0.05);B基因型患者血清ALT(323.57±596.83IU/L)、AST(254.88±460.94IU/L)、TBil(100.67±137.09μmol/L)均高于BC混合型(160.70±235.62IU/L、137.57±201.95IU/L、50.97±78.93μmol/L),差异有显著性意义(P<0.05);基因型分布在年龄、性别及HBeAg阳性率上均无差异;B基因型HBV DNA水平处于高度复制状态(>108copies/ml)的比例占49.12%(56/114),比BC混合型32.14%(18/56)高,BC混合型中中度复制(105~108copies/ml)和低度复制(<105copies/ml)占67.86%(38/56),比B型50.88%(58/114)高(P<0.05)。结论:本地区基因型以B型为主,BC混合型次之,C型少见;B型在AsC、HF、AHB、HCC中占优势,与疾病的活动度及预后密切相关;BC混合型在CHB和LC中多见,与乙型肝炎慢性化相关。     

Virological differences between patients infected with subtypes Ba and Bj of hepatitis B virus genotype B

BACKGROUND: Hepatitis B virus (HBV) genotype B is classified into subtype Ba with the recombination with genotype C in the precore region plus core gene and subtype Bj without recombination. Virological and clinical differences between infections with subtypes Ba and Bj, however, are yet to be determined. METHODS: During 1976 through 2001, 224 patients visited Toranomon Hospital in Tokyo, Japan who were infected with HBV genotype B. Subtypes of genotype B were determined by sequencing HBV-DNA recovered from sera for detecting recombination with genotype C. RESULTS: Subtype Ba was detected in 53 patients (24%) and Bj in 167 (75%); subtypes were not able to be determined in the remaining four (1%). The only virological difference was that detection of hepatitis B e antigen at the presentation was more frequent in the patients infected with subtype Ba than those with Bj (63% vs 33%, P = 0.016). There were no differences in the distribution of liver disease of various forms between the patients infected with subtypes Ba and Bj at presentation. No differences were noted, either, in the development of liver cirrhosis or hepatocellular carcinoma, or the loss of hepatitis B surface antigen from serum, between the patients infected with subtypes Ba and Bj during follow up of up to 26 years. CONCLUSIONS: Although there were some virological differences between the patients infected with subtypes Ba and Bj of HBV genotype B, they do not seem to influence the long-term clinical outcome.     

Long‐term entecavir therapy results in falls in serum hepatitis B surface antigen levels and seroclearance in nucleos(t)ide‐naïve chronic hepatitis B patients

Entecavir (ETV) is reported to result in suppression of hepatitis B virus DNA (HBV DNA) replication with minimal drug resistance. However, information on the long‐term effect of such therapy on serum hepatitis B surface antigen (HBsAg) level and elimination of HBsAg is not available. ETV therapy was started in 553 nucleos(t)ide‐naïve patients with chronic hepatitis B infection (HBeAg positive: 45%) in our hospital. Serum HBsAg levels were measured serially by the Architect assay. The median baseline HBsAg was 2180 IU/mL (0.12–243 000 IU/mL), and median follow‐up period was 3.0 years, with 529, 475, 355, 247 and 163 patients followed‐up for 1, 2, 3, 4 and 5 years, respectively. At year 5, the mean log HBsAg decline from baseline was −0.48 log IU/mL, and the cumulative HBsAg clearance rate was 3.5%. Multivariate analysis identified HBV DNA level at baseline (<3.0 log copies IU/mL, odd ratio = 10.2; 95% confidence interval = 1.87–55.5, P = 0.007) and HBsAg level (<500 IU/mL, odd ratio = 29.4; 95% confidence interval = 2.80–333, P = 0.005) as independent predictors of HBsAg seroclearance. These results indicate that although serum HBsAg level declines gradually during ETV therapy, HBsAg seroclearance remains a rare event.     

Maternal viral load and hepatitis B virus mother‐to‐child transmission risk: A systematic review and meta‐analysis

Aim

The aim of this study was to assess the relationship between maternal viral load and mother‐to‐child transmission (MTCT) risk in hepatitis B envelope antigen (HBeAg)‐positive mothers.

Methods

PubMed and Web of Science were systematically searched. We compared MTCT incidence between maternal hepatitis B virus (HBV)‐DNA‐positive and HBV‐DNA‐negative groups. We also examined the dose–response effect of this relationship.

Results

Twenty‐one studies with 10 142 mother–child pairs were included in the studies. The mean MTCT incidence was 13.1% in the maternal HBV‐DNA‐positive group, compared with 4.2% in the negative group. The summary MTCT odds ratio of maternal HBV‐DNA positive compared with negative was 9.895 (95% confidence interval [CI], 5.333 to 18.359; Z = 7.27, P < 0.00001) by random‐effects model. In maternal HBV‐DNA <6 log10 copies/mL, 6–8 log10 copies/mL, and >8 log₁₀ copies/mL level stratifications, the pooled MTCT incidences were 2.754% (95% CI, 1.198–4.310%; Z = 3.47, P = 0.001), 9.932% (95% CI, 6.349–13.516%; Z = 5.43, P < 0.00001), and 14.445% (95% CI, 8.317–20.572%; Z = 4.62, P < 0.00001), respectively. A significant linear dose–response association was found between maternal viral load and MTCT risk, with the points estimate of increased MTCT risk 2.705 (95% CI, 1.808–4.047) at 6 log10 copies/mL compared with reference (3 log10 copies/mL), and 7.316 (95% CI, 3.268–16.378) at 9 log₁₀ copies/mL. A significant non‐linear dose–response association was also found between maternal viral load and HBV MTCT risk (model χ² = 23.43, P < 0.00001).

Conclusion

Our meta‐analysis indicated that maternal viral load was an important risk factor for MTCT in HBeAg‐positive mothers, and maternal viral load was dose‐dependent with HBV MTCT incidence.     

HBV基因型与HBeAg的表达关系及其临床意义

目的观察慢性乙型肝炎病毒（HBV）感染者HBV基因型与HBeAg表达和病情轻重的关系。方法利用型特异性引物多重PCR方法检测HBV基因型,时间分辨荧光法检测HBV DNA。结果在120例慢性乙型肝炎病毒感染者中HBV基因型C型84例（70%）、B型31例（25.8%）,BC混合型5例（4.2%）,未发现A、D、E、F基因型;C型在慢性重型肝炎组最高（P〈0.05）;在C基因型中HBeAg（＋）患者较HBeAg（-）患者多见（P〈0.05）,在B基因型中,HBeAg（＋）和HBeAg（-）患者分布无明显差别。结论徐州地区HBV基因型以C型和B型多见,e抗原的表达率在C型中较高;基因型B型与C型相比,C型引起肝脏损伤重。