Hepatitis C virus in the new era:Perspectives in epidemiology,prevention,diagnostics and predictors of response to therapy

Despite the great successes achieved in the fields of virology and diagnostics,several difficulties affect improvements in hepatitis C virus(HCV)infection control and eradication in the new era.New HCV infections still occur,especially in some of the poorest regions of the world,where HCV is endemic and long-term sequelae have a growing economic and health burden.An HCV vaccine is still no available,despite years of researches and discoveries about the natural history of infection and host-virus interactions:several HCV vaccine candidates have been developed in the last years,targeting different HCV antigens or using alternative delivery systems,but viral variability and adaption ability constitute major challenges for vaccine development.Many new antiviral drugs for HCV therapy are in preclinical or early clinical development,but different limitations affect treatment validity.Treatment predictors are important tools,as they provide some guidance for the management of therapy in patients with chronic HCV infection:in particular,the role of host genomics in HCV infection outcomes in the new era of direct-acting antivirals may evolve for new therapeutic targets,representing a chance for modulated and personalized treatment management,when also very potent therapies will be available.In the present review we discuss the most recent data about HCV epidemiology,the new perspectives for the prevention of HCV infection and the most recent evidence regarding HCV diagnosis,therapy and predictors of response to it.

Predictors for Efficacy of Combination Therapy with a Nucleos(t)ide Analogue and Interferon for Chronic Hepatitis B

This study aims to explore the efficacy of interferon-α（IFN-α） combined with either entecavir（ETV） or adefovir（ADV） therapy versus IFN-α mono-therapy for chronic hepatitis B（CHB） patients, and to identify the factors associated with treatment outcomes. Totally, 159 CHB patients receiving interferon-based treatment for 48 weeks were enrolled in this retrospective study, including IFN-α mono-therapy group（group A, n=44）, IFN-α plus ADV group（group B, n=53） and IFN-α plus ETV group（group C, n=62）. The primary measures of efficacy assessments were the changes in HBs Ag. Cox regression analysis was used to identify the predictors of treatment outcomes. The predictive values of the factors were assessed by ROC analysis. For patients with baseline hepatitis B surface antigen（HBs Ag） level 〈1000 IU/m L, the reductions in mean HBs Ag levels at week 48 were greater in group C than that in group A（P〈0.05）. Higher rate of HBeAg seroconversion was achieved in the combined therapy group than in IFN-α mono-therapy group at week 48（P〈0.05）. Two factors were independently associated with HBeAg seroconversion： baseline HBeAg level 〈2.215 log10 index/m L and △HBeAg（decline in HBeAg from baseline） 〉0.175 log10 at week 12. In conclusion, interferon-α plus ETV therapy can accelerate HBs Ag decline as compared with interferon-α mono-therapy in CHB patients with lower baseline HBs Ag levels, and the combination therapy was superior to IFN-α mono-therapy in increasing the rate of HBeAg seroconversion. Baseline HBeAg and △HBeAg at week 12 can independently predict HBeAg seroconversion in patients subject to interferon-based therapy for 48 weeks.

Chinese Consensus on Combination Therapy of Chronic Hepatitis B

In May 2011,editorial boards of Chinese Journal of Experimental and Clinical Infectious Diseases (Electronic Edition),Chinese Journal of Liver Diseases (Electronic Edition) and Infection International (Electronic Edition) organized an expert committee to form an expert consensus on antiviral combination therapy of chronic hepatitis B (CHB).The consensus publication promoted and standardized the combination therapy concept of chronic hepatitis B.Clinical evidence of combination therapy for CHB is incomplete.The concept of combination therapy is gradually extended,from combination of antiviral drugs plus antiviral drugs,to antiviral drugs plus hepatoprotective drugs,and antiviral drugs plus immunomodulatory drugs.Therefore,editorial boards once again asked experts to analyze the new clinical evidence,and form the expert consensus on combination therapy of chronic hepatitis B.The formulation of this consensus is according to the principles of evidence-based medicine.Large number of clinical studies of combination therapy is still in progress.This consensus can not fully answer all the problems encountered in the combination therapy of CHB.With the progress of clinical practice of antiviral therapy,and the accumulation of evidence in combination therapy,the expert committee will update the consensus timely.

Efficacy of intramuscular matrine in the treatment of chronic hepatitis B

BACKGROUND: Hepatitis B virus (HBV) infection, a glo- bal public health problem, is the leading cause of cirrhosis and hepatocellular carcinoma (HCC) worldwide. There are more than 350 million HBV carriers in the world and up to one million die annually due to hepatitis B associated liv- er disease. So far no optimal treatment is available for pa- tients with chronic hepatitis B. In the paper we investigated the efficacy of intramuscular matrine in the treatment of chronic hepatitis B. METHODS: One hundred and twenty patients with chronic hepatitis B were randomly divided into matrine treatment group (n =60) and control group (n =60). The patients of the matrine group were given intramuscularly with matrine (an alkaloid extracted from a traditional Chinese herb Radix Sophorae Flavescentis by Guangzhou Ming Xing Pharmaceu cal Factory, Guangzhou, China) of 100 mg daily for 90 days in addition to conventional liver-protective drugs in- cluding glucurone, inosine, compound vitamin B and caryophyllin. The control group received conventional liv- er-protective drugs alone. Clinical manifestations and labo- ratory parameters including liver biochemistry and serum hepatitis B virus markers were monitored before and after treatment in the two groups. RESULTS: Significant differences were seen between the two groups in terms of improvement of clinical symptoms and signs, recovery of liver functions, and serum conver- sion from hepatitis Be antigen to HBe antibody and from positive to negative serum HBV DNA (P <0.05-0.01). The result of the matrine group was more marked than that of the control group. Serious side-effects were not observed except mild pain at the site of injection of matrine in a few patients. CONCLUSION: These results indicate that intramuscular matrine may be an economical, efficacious, safe drug for the treatment of chronic hepatitis B.

Peginterferon and ribavirin treatment for hepatitis C virus infection

Pegylated interferon α (IFNα) in combination with ribavirin is currently recommended as a standard-of-care treatment for chronic hepatitis C virus (HCV) infection. This combination therapy has drastically improved the rate of sustained virological response, specifically in difficult-to-treat patients. Recently, individualized treatment, such as response-guided therapy, is being developed based on host-, HCV- and treatment-related factors. Furthermore, modified regimens with currently available medications, novel modified IFNα and ribavirin or combinations with specifically targeted antiviral therapy for HCV agents, are currently being investigated. The purpose of this review is to address some issues and epoch-making topics in the treatment of chronic HCV infection, and to discuss more optimal and highly individualized therapeutic strategies for HCV-infected patients.

Understanding the interaction of hepatitis C virus with host DEAD-box RNA helicases

The current therapeutic regimen to combat chronic hepatitis C is not optimal due to substantial side effects and the failure of a significant proportion of patients to achieve a sustained virological response. Recently developed direct-acting antivirals targeting hepatitis C virus (HCV) enzymes reportedly increase the virologic response to therapy but may lead to a selection of drug-resistant variants. Besides direct-acting antivirals, another promising class of HCV drugs in development include host targeting agents that are responsible for interfering with the host factors crucial for the viral life cycle. A family of host proteins known as DEAD-box RNA helicases, characterized by nine conserved motifs, is known to play an important role in RNA metabolism. Several members of this family such as DDX3, DDX5 and DDX6 have been shown to play a role in HCV replication and this review will summarize our current knowledge on their interaction with HCV. As chronic hepatitis C is one of the leading causes of hepatocellular carcinoma, the involvement of DEAD-box RNA helicases in the development of HCC will also be highlighted. Continuing research on the interaction of host DEAD-box proteins with HCV and the contribution to viral replication and pathogenesis could be the panacea for the development of novel therapeutics against HCV.

New therapeutic opportunities for Hepatitis C based on small RNA

Hepatitis C virus （HCV） infection is one of the major causes of chronic liver disease, including cirrhosis and liver cancer and is therefore, the most common indication for liver transplantation. Conventional antiviral drugs such as pegylated interferon-alpha, taken in combination with ribavirin, represent a milestone in the therapy of this disease. However, due to different viral and host factors, clinical success can be achieved only in approximately half of patients, making urgent the requirement of exploiting alternative approaches for HCV therapy. Fortunately, recent advances in the understanding of HCV viral replication and host cell interactions have opened new possibilities for therapeutic intervention. The most recent technologies, such as small interference RNA mediated gene-silencing, antisense oligonucleotides （ASO）, or viral vector based gene delivery systems, have paved the way to develop novel therapeutic modalities for HCV. In this review, we outline the application of these technologies in the context of HCV therapy. In particular, we will focus on the newly defined role of cellular microRNA （miR-222） in viral replication and discuss its potential for HCV molecular therapy.

Management of chronic hepatitis B in pregnancy

Pregnancy associated with chronic hepatitis B (CHB) is a common and important problem with unique challenges. Pregnant women infected with CHB are different from the general population, and their special problems need to be considered: such as the effect of hepatitis B virus (HBV) infection on the mother and fetus, the effect of pregnancy on replication of the HBV, whether mothers should take HBV antiviral therapy during pregnancy, the effect of these treatments on the mother and fetus, how to carry out immunization of neonates, whether it can induce hepatitis activity after delivery and other serious issues. At present, there are about 350 million individuals with HBV infection worldwide, of which 50% were infected during the perinatal or neonatal period, especially in HBV-endemic countries. Currently, the rate of HBV infection in thechild-bearing age group is still at a high level, and the infection rate is as high as 8.16%. Effective prevention of mother-to-child transmission is an important means of reducing the global burden of chronic HBV infection. Even after adopting the combined immunization measures, there are still 5%-10% of babies born with HBV infection in hepatitis B e antigen positive pregnant women. As HBV perinatal transmission is the main cause of chronic HBV infection, we must consider how to prevent this transmission to reduce the burden of HBV infection. In this population of chronic HBV infected women of childbearing age, specific detection, intervention and follow-up measures are particularly worthy of attention and discussion.

Characterization of hepatic progenitors from human fetal liver during second trimester

AIM： To enrich hepatic progenitors using epithelial cell adhesion molecule （EpCAM） as a marker from human fetal liver and investigate the expression of human leukocyte antigen （HLA） and their markers associated with hepatic progenitor cells. METHODS： EpCAM ＋ve cells were isolated using magnetic cell sorting （MACS） from human fetuses （n = 10） at 15-25 wk gestation. Expression of markers for hepatic progenitors such as albumin, alpha-fetoprotein （AFP）, CD29 （integrin ~1）, CD49f （integrin c^6） and CD90 （Thy 1） was studied by using flow cytometry, immunocytochemistry and RT-PCR; HLA class Ⅰ （A, B, C） and class Ⅱ （DR） expression was studied by flow cytometry only. RESULTS： FACS analysis indicated that EpCAM ＋ve cells were positive for CD29, CD49f, CD90, CD34, HLA class I, albumin and AFP but negative for HLA class Ⅱ （DR） and CD45. RT PCR showed that EpCAM ＋ve cells expressed liver epithelial markers （CK18）, biliary specific marker （CK19） and hepatic markers （albumin, AFP）. On immunocytochemical staining, EpCAM ＋ve cells were shown positive signals for CK18 and albumin. CONCLUSION： Our study suggests that these EpCAM ＋ve cells can be used as hepatic progenitors for cell transplantation with a minimum risk of alloreactivity and these cells may serve as a potential source for enrichment of hepatic progenitor.

Correlation between constitution of Yin deficiency syndrome and polymorphism of HLADQA1 / treatment response of Peg-IFNα therapy in HBeAg positive chronic hepatitis B patients

Objective To observe the correlation between constitution of yin deficiency syndrome(YDS)and polymorphism of HLA-DQA1/treatment response of Peg-IFNαtherapy in HBe Ag positive chronic hepatitis B(CHB)patients,and to explore constitution of Chinese medicine(CM)in response to interferon therapy.Methods Totally 120 HBe Ag positive CHB patients who were

Specific anti-viral effects of RNA interference on replication and expression of hepatitis B virus in mice

Background RNA interference （RNAi） is a powerful tool to silence gene expression post-transcriptionally. Our previous study has demonstrated that small interfering RNAs （siRNAs） have sufficiently inhibited hepatitis B virus （HBV） replication and expression in vitro. In this study we observed the RNAi-mediated inhibitory effects on HBV replication in mice models and accessed the specificity of these effects. Methods A mutant RNAi vector （pSI-C mut） with two base pairs different from the original target gene sequence at the RNAi vector （pSI-C） was constructed according to the method described in this study, A mouse model of acute hepatitis B virus infection was established by injecting naked plasmid pHBV1.3 via the tail vein with acute circulatory overload, pSI-C, pSI-C mut and the irrelevant RNAi control plasmid for green fluorescent protein （GFP） gene, pSIGFP were respectively delivered with pHBV1.3 by tail vein injection method. Six days post injection, enzyme-linked immunosorbent assay （ELISA） assay was used to measure the concentration of HBV surface antigen （HBsAg） in mouse serum, immunohistochemical straining method was used to visualize the expressin of HBV core protein （HBcAg） in liver tissues, and the transcriptional level of HBV C mRNA in liver tissues was detectedd by reverse transcriptase PCR （RT-PCR） analysis. Results Injection of pSI-C exerted magnificent and specific inhibitory effects on the replication and expression of HBV in the murine model. After 6-day post-injection （ p. i. ）, the OD values were shown to be 5.07 ± 1.07 in infecting group and 0.62 ± 0. 59 in pSI-C group. The concentration of HBsAg in pSI-C group was significantly lower than that in infecting group （ P 〈 0. 01 ）. Liver intracellular synthesis of viral core protein was sharply reduced to 0. 9% ±0. 1%, compared with 5.4% ± 1.2% of positive hepatocytes in infecting group （P 〈0. 01 ）, and the transcriptional level of HBV C mRNA was greatly reduced by 84. 7%. However, the irrelevant RNAi control plasmid （pSIGFP）, and the pSI-C mut did not show the same robust inhibitory effects as pSI-C. Conclusion pSI-C exert efficient and specific inhibitory effects on HBV replication and expression in mice models.

Management of chronic hepatitis B during pregnancy

Chronic hepatitis B is globally prevalent and is a major cause of cirrhosis and hepatocellular carcinoma.Despite immunoprophylaxis against hepatitis B in pregnancy,perinatal transmission still occurs in at least 10%of the children born to a mother with high level of viremia.Decisions regarding hepatitis B therapy during pregnancy must take into account the benefits and safety for both the mother and the unborn baby.In this review,we summarize the current treatment options for chronic hepatitis B with a focus on management during pregnancy and the evidence-based strategies to prevent vertical transmission of hepatitis B virus(HBV).

Risk assessment and management of hepatitis B reactivation from direct-acting antivirals for hepatitis C

Although hepatitis B virus(HBV)reactivation has been reported in hepatitis C patients who received interferon therapy,rare cases of HBV reactivation occur in the context of direct-acting antiviral(DAA)agent therapy for treatment of hepatitis C virus(HCV)infection.Recent studies observed that the reactivations were predominantly in hepatitis B surface antigen(HBsAg)positive patients,but reactivation can rarely occur in patients who are HBsAg negative and hepatitis B core antibody(HBcAb)positive.The severity of an HBV flare varies.In some cases,severe liver injury or fulminant hepatic failure may occur.HBV reactivation may occur regardless of HCV genotype and type of DAA regimens.The onset of HBV reactivation can range from 4 to 48 weeks after initiating DAA therapy.These patients may have undetectable levels of HBV deoxyribonucleic acid(DNA)prior to DAA treatment.Pre-emptive antiviral therapy for HBV should be considered in HBsAg-positive patients with high levels of viremia who are not receiving HBV treatment.If HBV DNA viral load is less than the guideline criteria for HBV treatment,one should consider pre-emptive HBV antiviral versus HBV DNA monitoring during DAA therapy.For patients who are HBsAg negative but HBcAb positive,close monitoring of serum alanine aminotransferase(ALT)levels during/post-treatment is highly recommended.The current review summarizes the recommendations of different society guidelines and discusses the appropriate management strategies in various patient profiles.

Inhibitory effect of retroviral vector containing anti-sense Smad_4 gene on Ito cell line, LI90

Background Transforming growth factor-β1 (TGF-β1) exerts strong fibrogenic potential in culture-activated HSCs Smad 4 is a key intracellular mediator for the transforming growth factor-β (TGF-β) superfamily of growth factors The aim of this study was to assess the effects of the antisense Smad 4 gene on Ito cell line, LI90 Methods The recombinant retroviral vector pLXSN-Smad 4 was constructed by cloning the rat antisense Smad 4 cDNA into the retroviral vector pLXSN Retroviruses with or without the antisense gene were obtained by transfecting pLXSN-Smad 4 and pLXSN vectors into PA317 cells Human hepatic stellate cells (HSCs) LI90 were infected with these retroviruses followed by selection with G418 The expression of Smad 4 was detected by Northern and Western blots Cell biological characteristics, including cell growth curve, 3H-TdR and 3H-proline uptake by HSCs and the production of extracellular matrix were assessed Results mRNA and protein expressions of Smad 4 in LI90 cells transfected with retrovirus containing the antisense Smad 4 gene were much lower than those in LI90 cells transfected with empty vector or parental LI90 cells Cells hypoexpressing the Smad 4 gene exhibited a slower rate of growth, a lower uptake of 3H-TdR and 3H-proline ( P <0 01), and smaller production of th extracellular matrix, compared with parental LI90 cells and cells transfected with empty retrovirus Conclusions The antisense Smad 4 gene can suppress the expression of the Smad 4 gene, reduce endogenous production of Smad 4 mRNA and protein, block TGF-β1 signaling pathway, inhibit activation of Ito cells, obstruct the growth of Ito cells, decrease the production of the extracellular matrix (ECM) Our results may provide a basis for the development of antifibrotic gene therapy