Current status of drug therapy for chronic hepatitis B

In this editorial,we comment on the article by Meng et al.Chronic hepatitis B(CHB)is a significant global health problem,particularly in developing countries.Hepatitis B virus(HBV)infection is one of the most important risk factors for cirrhosis and hepatocellular carcinoma.Prevention and treatment of HBV are key measures to reduce complications.At present,drug therapy can effectively control virus replication and slow disease progression,but completely eliminating the virus remains a challenge.Anti-HBV treatment is a long-term process,and there are many kinds of antiviral drugs with different mechanisms of action,it is essential to evaluate the safety and efficacy of these drugs to reduce side effects and improve patients’compliance.We will summarize the current status of CHB drug treatment,hoping to provide a reference for the selection of clinical antiviral drugs.

Antiviral therapy for hepatitis B virus infection is beneficial for the prognosis hepatocellular carcinoma

In this editorial,we comment on the article by Mu et al,published in the recent issue of the World Journal of Gastrointestinal Oncology.We pay special attention to the immune tolerance mechanism caused by hepatitis B virus(HBV)infection,the pathogenesis of hepatocellular carcinoma(HCC),and the role of antiviral therapy in treating HCC related to HBV infection.HBV infection leads to systemic innate immune tolerance by directly inhibiting pattern recognition receptor recognition and antiviral signaling pathways,as well as by inhibiting the immune functions of macrophages,natural killer cells and dendritic cells.In addition,HBV leads to an immunosuppressive cascade by expressing inhibitory molecules to induce exhaustion of HBV-specific cluster of differentiation 8+T cells,ultimately leading to long-term viral infection.The loss of immune cell function caused by HBV infection ultimately leads to HCC.Long-term antiviral therapy can improve the prognosis of patients with HCC and prevent tumor recurrence and metastasis.

Perioperative remedial antiviral therapy in hepatitis B virus-related hepatocellular carcinoma resection:How to achieve a better outcome

BACKGROUND Although the benefits of antiviral therapy for hepatitis B virus(HBV)-related hepatocellular carcinoma(HCC)have been proven,researchers have not con-firmed the differences in patient outcomes between patients who received preoperative antiviral therapy for a period of time(at least 24 wk)and patients who received remedial antiviral therapy just before radical resection for HBV-related HCC.AIM To investigate the efficacy of perioperative remedial antiviral therapy in patients with HBV-related HCC.METHODS A retrospective study of patients who underwent radical resection for HBV-related HCC at the First Affiliated Hospital of Xi’an Jiaotong University from January 2016 to June 2019 was conducted.Considering the history of antiviral therapy,patients were assigned to remedial antiviral therapy and preoperative antiviral therapy groups.RESULTS Kaplan–Meier analysis revealed significant differences in overall survival(P<0.0001)and disease-free survival(P=0.035)between the two groups.Multivariate analysis demonstrated that a history of preoperative antiviral treatment was independently related to improved survival(hazard ratio=0.27;95%confidence interval:0.08-0.88;P=0.030).CONCLUSION In patients with HBV-related HCC,it is ideal to receive preoperative long-term antiviral therapy,which helps patients tolerate more extensive hepatectomy;however,remedial antiviral therapy,which reduces preoperative HBV-DNA levels to less than 4 Log10 copies DNA/mL,can also result in improved outcomes.

Prevention of hepatitis B reactivation in patients with hematologic malignancies treated with novel systemic therapies:Who and Why?

The risk of reactivation in patients with chronic or past/resolved hepatitis B virus(HBV)infection receiving chemotherapy or immunosuppressive drugs is a wellknown possibility.The indication of antiviral prophylaxis with nucleo(t)side analogue is given according to the risk of HBV reactivation of the prescribed therapy.Though the advent of new drugs is occurring in all the field of medicine,in the setting of hematologic malignancies the last few years have been characterized by several drug classes and innovative cellular treatment.As novel therapies,there are few data about the rate of HBV reactivation and the decision of starting or not an antiviral prophylaxis could be challenging.Moreover,patients are often treated with a combination of different drugs,so evaluating the actual role of these new therapies in increasing the risk of HBV reactivation is difficult.First results are now available,but further studies are still needed.Patients with chronic HBV infection[hepatitis B surface antigen(HBsAg)positive]are reasonably all treated.Past/resolved HBV patients(HBsAg negative)are the actual area of uncertainty where it could be difficult choosing between prophylaxis and pre-emptive strategy.

Prediction model for hepatitis B e antigen seroconversion in chronic hepatitis B with peginterferon-alfa treated based on a responseguided therapy strategy

BACKGROUND Models for predicting hepatitis B e antigen(HBeAg)seroconversion in patients with HBeAg-positive chronic hepatitis B(CHB)after nucleos(t)ide analog treatment are rare.AIM To establish a simple scoring model based on a response-guided therapy(RGT)strategy for predicting HBeAg seroconversion and hepatitis B surface antigen(HBsAg)clearance.METHODS In this study,75 previously treated patients with HBeAg-positive CHB underwent a 52-week peginterferon-alfa(PEG-IFNα)treatment and a 24-wk follow-up.Logistic regression analysis was used to assess parameters at baseline,week 12,and week 24 to predict HBeAg seroconversion at 24 wk post-treatment.The two best predictors at each time point were used to establish a prediction model for PEG-IFNαtherapy efficacy.Parameters at each time point that met the corresponding optimal cutoff thresholds were scored as 1 or 0.RESULTS The two most meaningful predictors were HBsAg≤1000 IU/mL and HBeAg≤3 S/CO at baseline,HBsAg≤600 IU/mL and HBeAg≤3 S/CO at week 12,and HBsAg≤300 IU/mL and HBeAg≤2 S/CO at week 24.With a total score of 0 vs 2 at baseline,week 12,and week 24,the response rates were 23.8%,15.2%,and 11.1%vs 81.8%,80.0%,and 82.4%,respectively,and the HBsAg clearance rates were 2.4%,3.0%,and 0.0%,vs 54.5%,40.0%,and 41.2%,respectively.CONCLUSION We successfully established a predictive model and diagnosis-treatment process using the RGT strategy to predict HBeAg and HBsAg seroconversion in patients with HBeAg-positive CHB undergoing PEG-IFNαtherapy.

Timing of antiviral therapy in patients with hepatitis B virus related hepatocellular carcinoma undergoing hepatectomy

Globally,hepatocellular carcinoma(HCC)is among the most prevalent and deadly cancers.Hepatitis B virus(HBV)infection is an important etiology and disease progression factor for HCC.Hepatectomy is a widely accepted curative treatment for HCC,but the long-term survival rate is still unsatisfactory due to the high recurrence rate after resection.Preoperative or postoperative antiviral therapy plays an important role in improving the prognosis for HBV-related HCC patients who underwent hepatectomy.However,many patients miss out on the chance to receive long-term preoperative antiviral medication because their HBV and HCC infections are discovered concurrently,necessitating the start of remedial antiviral therapy in the perioperative phase.Therefore,it is of great value to know when antiviral therapy is more appropriate and whether perioperative rescue antiviral therapy can achieve the effect of preoperative long-term antiviral therapy.

Functional cure of chronic hepatitis B-hope or hype?

Chronic hepatitis B constitutes a substantial disease burden worldwide.The steps advocated by the World Health Organization in 2016 to eradicate hepatitis B by 2030 has failed to achieve significant progress,especially with respect to immu-nization coverage and linkage to care.The lack of governmental and public awar-eness regarding the long-term implications of hepatitis B burden cause under-funding of developmental projects.The presently approved treatment modalities have limited efficacy in complete viral eradication,hence the need for newer molecules to achieve functional cure(sustained undetectable hepatitis B surface antigen(HBsAg)and hepatitis B virus DNA in peripheral blood after a finite period of therapy).However,preliminary results from trials of novel therapies show their inadequacy to achieve this end by themselves but better performance with a low baseline serum HBsAg with nucleos(t)ide analogues(NA)treatment which need to be combined with/without pegylated interferon as an immu-nomodulator.Such therapy is limited by cost and adverse events and need to show incremental benefit over the standard of care(long-term NA therapy)with respect to efficacy and drug toxicities,making the development process tenuous.Thus,while such therapies continue to be tested,strategies should still focus on prevention of transmission by non-pharmaceutical measures,vaccination and increasing linkage to care.

Influence of nonalcoholic fatty liver disease on the therapeutic effect of nucleoside(acid)analogs for hepatitis B virus

BACKGROUND The effect of nonalcoholic fatty liver disease(NAFLD)on the efficacy of nucleoside analogues(NAs)in antiviral therapy for patients with chronic hepatitis B(CHB)remains controversial.AIM To investigate the influence of NAFLD on virological response in CHB patients undergoing NAs treatment.METHODS Logistic regression analysis was conducted on a cohort of 465 CHB patients from two hospitals to determine whether NAFLD was a risk factor for adverse reactions to NAs.CHB patients were followed up for more than 28 months after initial antiviral treatment,and further validation was performed using different viral load populations.RESULTS NAFLD was identified as an independent risk factor for partial virological response following antiviral therapy with NAs(odds ratio=1.777,P=0.017).In our subsequent analysis focusing on CHB patients with high viral load,the NAFLD group exhibited significantly longer virus shedding time and lower proportion of the complete virological response compared with the non-NAFLD group(16.8±6.1 vs 13.0±6.8,P<0.05).During the 24-month period of antiviral treatment with NAs,hepatitis B virus(HBV)DNA levels decreased slowly in the NAFLD group,and the negative conversion rate of HBV was notably lower than that observed in non-NAFLD group(P=0.001).Similar results were obtained when analyzing patients with low baseline HBV viral load within the NAFLD group.CONCLUSION Coexistence of NAFLD may diminish virological response among CHB patients receiving antiviral treatment with NAs.

De novo combined lamivudine and adefovir dipivoxil therapy vs entecavir monotherapy for hepatitis B virus-related decompensated cirrhosis

AIM:To compare efficacy of combined lamivudine(LAM)and adefovir dipivoxil(ADV)therapy with that of entecavir(ETV)monotherapy for hepatitis B virus(HBV)-related decompensated liver cirrhosis.METHODS:A total of 120 na ve patients with HBVrelated decompensated cirrhosis participated in this study.Sixty patients were treated with combined LAM and ADV therapy(LAM+ADV group),while the other60 were treated with ETV monotherapy(ETV group)for two years.Tests for liver and kidney function,alpha-fetoprotein,HBV serum markers,HBV DNA load,prothrombin time(PT),and ultrasonography or computed tomography scan of the liver were performed every1 to 3 mo.Repeated measure ANOVA and theχ2test were performed to compare the efficacy,side effects,and the cumulative survival rates at 48 and 96 wk.RESULTS:Forty-five patients in each group were observed for 96 wk.No significant differences in HBV DNA negative rates and alanine aminotransferase(ALT)normalization rates at weeks 48(χ2=2.12 and 2.88)and96(χ2=3.21 and 3.24)between the two groups were observed.Hepatitis B e antigen seroconversion rate in the LAM+ADV group at week 96 was significantly higher in the ETV group(43.5%vs 36.4%,χ2=4.09,P<0.05).Viral breakthrough occurred in 2 cases(4.4%)by week 48 and in 3 cases(6.7%)by week 96 in the LAM+ADV group,and no viral mutation was detected.In the ETV group,viral breakthrough occurred in 1 case(2.2%)at the end of week 96.An increase in albumin(F=18.9 and 17.3),decrease in total bilirubin and in ALT(F=16.5,17.1 and 23.7,24.8),reduced PT(F=22.7 and 24.5),and improved Child-Turcotte-Pugh and the model for end-stage liver disease scores(F=18.5,17.8,and 24.2,23.8)were observed in both groups.The cumulative rates of mortality and liver transplantation were 16.7%(10/60)and 18.3%(11/60)in the LAM+ADV and ETV groups,respectively.CONCLUSION:Both LAM+ADV combination therapy and ETV monotherapy can effectively inhibit HBV replication,improve liver function,and decrease mortality.

Postoperative adjuvant antiviral therapy for hepatitis B/C virus-related hepatocellular carcinoma:A meta-analysis

AIM:To investigate the impact of postoperative antiviral treatment on tumor recurrence and survival of patients with chronic hepatitis B virus(HBV) or hepatitis C virus(HCV) infection-related primary hepatocellular carcinoma(HCC) after curative therapy.METHODS:We performed a meta-analysis of randomized and non-randomized control trials from electronic search and manual search.The fixed effect model of Mantel-Haenszel method and the random effect model of Der Simonian and Laird method were used for homogeneous and heterogeneous studies,respectively.Seven HCV-related studies,three HBV-related studies and three studies on HBV or HCV-related HCC were identified.RESULTS:A total of 1224 patients were included in this analysis.The estimated odds ratios(OR) for the 1-,2-,3-and 5-year recurrence were 0.54 [15.4% vs 24.1%,95% confidence interval(CI):0.32-0.89,P=0.02],0.42(36.9% vs 58.0%,95% CI:0.19-0.90,P=0.03),0.37(47.9% vs 63.8%,95% CI:0.19-0.71,P=0.003),and 0.32(66.7% vs 74.3%,95% CI:0.15-0.66,P=0.002),respectively;and the OR for the 1-,2-,3-,5-and 7-year mortality were 0.23(1.2% vs 9.1%,95% CI:0.07-0.71,P=0.01),0.31(6.4% vs 22.1%,95% CI:0.12-0.79,P=0.01),0.43(12.7% vs 20.8%,95% CI:0.21-0.89,P=0.02),0.42(25.1% vs 42.0%,95% CI:0.27-0.66,P=0.0002) and 0.28(31.9% vs 52.2%,95% CI:0.13-0.59,P=0.0008).CONCLUSION:This meta-analysis indicates the postoperative antiviral therapy,interferon in particular,may serve as a favorable alternative to reduce recurrence and mortality in patients with HBV/HCV related HCCs.

Antiviral therapy for hepatitis B virus associated hepatic failure

BACKGROUND: Chronic hepatitis B virus (HBV) infection remains a major global health issue, and the prognosis of patients with HBV-associated fulminant hepatic failure is extremely poor. The application of antiviral therapies has led to significant improvements in patient outcomes. This article aimed to review the current strategies in antiviral treatment of HBV-associated fulminant hepatic failure. DATA SOURCES: Literature search was conducted using PubMed on the related subjects. Part of the data was from the most recent work of the authors' laboratory. RESULTS: Hepatitis B immunoglobulin in prevention of recurrent HBV infection after orthotopic liver transplantation (OLT) has been proven effective. However, its cost is high, and significant side effects have been found to induce viral mutations. Lamivudine has a potent suppression for HBV replication and an excellent safety profile in decompensated cirrhotic patients, but its major drawback is the high rate of drug-resistance. Adefovir is effective for lamivudine-resistance strains in the post-OLT situation, and its drug-resistance rate is relatively low. Combination therapies such as hepatitis B immunoglobulin combined with lamivudine and lamivudine combined with adefovir have been widely adopted for prophylaxis against HBV recurrence of infection after OLT. Entecavir, telbivudine, tenofovir and other newer agents have been widely used in antiviral therapy. CONCLUSIONS: The prognosis of HBV-associated fulminant hepatic failure is being transformed by developments in antiviral therapy. However, it should be noticed that HBV is controlled but never eliminated, and drug-resistance still remains a major issue. Hopefully, newer strategies may help to solve these problems.

Impact of antiviral therapy on post-hepatectomy outcome for hepatitis B-related hepatocellular carcinoma

The outcome after curative resection for hepatocellular carcinoma(HCC)remains unsatisfactory due to the high recurrence rate after surgery.In patients with hepatitis B virus(HBV)-related HCC,which is the majority of patients with HCC in Asia,a high viral load is a strong risk factor for HCC recurrence.It is logical to believe that antiviral therapy may improve the postoperative outcome by promoting viral clearance and hepatocyte regeneration,as well as improving residual liver volume in HCC patients with hepatitis B.However,the effect of antiviral therapy on clinical outcomes after liver resection in patients with HBV-related HCC remains to be established.There are two main groups of antiviral treatment for HBV-oral nucleos(t)ide analogues and interferon.Interferon treatment reduces the overall incidence of HBV-related HCC in sustained re-sponders.However,side effects may limit its long-term clinical application.Nucleos(t)ide analogues carry fewer side effects and are potent in terms of viral suppression when compared to interferon and are typically implemented for patients with more advanced liver diseases.They may also improve the outcome after curative resection for HBV-related HCC.There are increasing evidence to suggest that antiviral therapy could suppress HBV,decrease the perioperative reactivation of viral replication,reduce liver injury,preserve the liver function before and after operation,and may lower the risk of HCC recurrence.After all,antiviral therapy may improve the survival after liver resection by reducing recurrence and delaying the liver damage by the virus,resulting in a higher chance of receiving aggressive salvage therapy during HCC recurrence.

Hepatitis B virus reactivation associated with antirheumatic therapy: risk and prophylaxis recommendations

Accompanying the increased use of biological and non-biological antirheumatic drugs,a greater number of cases of hepatitis B virus(HBV) reactivation have been reported in inactive hepatitis B surface antigen(HBs Ag) carriers and also in HBs Ag-negative patients who have resolved HBV infection. The prevalence of resolved infection varies in rheumatic disease patients,ranging from 7.3% to 66%. Through an electronic search of the Pub Med database,we found that among 712 patients with resolved infection in 17 observational cohort studies,12 experienced HBV reactivation(1.7%) during biological antirheumatic therapy. Reactivation rates were 2.4% for etanercept therapy,0.6% for adalimumab,0% for infliximab,8.6% for tocilizumab,and 3.3% for rituximab. Regarding non-biological antirheumatic drugs,HBV reactivation was observed in 10 out of 327 patients with resolved infection from five cohort studies(3.2%). Most of these patients received steroids concomitantly. Outcomes were favorable in rheumatic disease patients. A number of recommendations have been established,but most of the supporting evidence was derived from the oncology and transplantation fields. Compared with patients in these fields,rheumatic disease patients continue treatment with multiple immunosuppressants for longer periods. Optimal frequency and duration of HBV-DNA monitoring and reliable markers for discontinuation of nucleoside analogues should be clarified for rheumatic disease patients with resolved HBV infection.

Antiviral therapy and resistance with hepatitis B virus infection

Hepatitis B virus （HBV） infection is still the most common cause of hepatocellular carcinoma and liver drrhosis world wide. Recently, however, there has been quite dramatic improvement in the understanding of HBV assodated liver disease and its treatment. It has become dear that high viral replication is a major risk factor for the development of both cirrhosis and hepatocellular carcinoma. Early studies have shown lamivudine lowers the risk of HBV associated complications. There are currently three nucleos（t）ides licensed, in addition to interferon, and there are more drugs coming to the market soon. Interferon or its pegylated counterpart are still the only options for treatment with defined end points, while nudeos（t）ides therapy is used mostly for long term treatment. Combination therapies have not been shown to be superior to monotherapy in naive patients, however, the outcome depends on how the end point is defined. Interferon plus lamivudine achieves a higher viral suppression than either treatment alone, even though Hbe-seroconversion was not different after a one year treatment. HBV-genotypes emerge as relevant factors, with genotypes ＂A＂ and ＂B＂ responding relatively well to interferon, achieving up to 20% HBsAg clearance in the case of genotype ＂A＂. In addition to having a defined treatment duration, interferon has the advantage of lack- ing resistance selection, which is a major drawback for lamivudine and the other nucleos（t）ides. The emergence of resistance against adefovir and entecavir is some- what slower in na＇fve compared to lamivudine resistant patients. Adefovir has a low resistance profile with 3%, 9%, 18%, and 28% after 2, 3, 4, and 5 years, respectively, while entecavir has rarely produced resistance in naive patients for up to 3 years.

Antiviral therapy for chronic hepatitis B: Combination of nucleoside analogs and interferon

The ideal goal of chronic hepatitis B(CHB) treatment should be suppression of emergence of hepatocellular carcinoma through the disappearance of hepatitis B s antigen(HBs Ag) rather than the control of serum hepatitis B virus-DNA level. For this purpose, various types of combination therapies using nucleoside analogs(NAs) and interferon(IFN) have been conducted. The therapeutic effects of combination of two different kinds of agents are better than those of the monotherapy using NAs or IFN alone, probably because different pharmaceutical properties might act in a coordinated manner. Recently, combination therapies with NAs and IFN and sequential therapies with NAs administration followed by IFN therapy have been routinely employed. We previously reported that combination therapy using entecavir(ETV) and pegylated(PEG)-IFN showed antiviral effects in 71% of CHB patients; the effect of this combination was better than that using lamivudine(LAM) and PEG-IFN. This is partially explained by the better antiviral effects of ETV than those of LAM. In our analysis, the cohort of CHB consisted of the patients who showed a flare-up of hepatitis before antiviral therapy, and their baseline HBs Ag levels were relatively low. Therefore, in addition to the combination of the agents, the appropriate selection of patients is critical to achieve a good viral response.

Interferon and lamivudine combination therapy versus lamivudine monotherapy for hepatitis B e antigen-negative hepatitis B treatment:a meta-analysis of randomized controlled trials

BACKGROUND: It has been demonstrated that only a minority of patients with hepatitis B e antigen (HBeAg) negative chronic hepatitis B (CHB) obtain a sustained response after either interferon (IFN) or nucleos (t)ide analogue monotherapy. Therefore, combination therapy of drugs with synergistic antiviral effects was proposed to have a sustained response in these patients. We compared the effect and safety of lamivudine monotherapy and its combination with IFN including conventional interferon (CON-IFN) and pegylated interferon (PEG-IFN) for HBeAg-negative CHB patients. DATA SOURCES: A group of three independent reviewers identified 9 eligible randomized controlled trials through electronic searches (MEDLINE, OVID, EMBASE, the Cochrane Library Clinical Trials Registry, and the Chinese Medical Database), manual searches, and contact with experts. Sustained virological and biochemical responses were defined as primary efficacy measures. We performed quantitative meta-analyses to assess differences between CON-IFN plus lamivudine combination and lamivudine monotherapy groups. RESULTS: No greater sustained virological and biochemical rates were found in patients receiving CON-IFN/lamivudine combination therapy [29.1% vs. 26.7%, odds ratio (OR)=0.98, 95% confidence interval (CI) 0.65-1.50, P=0.94, and 41.8% vs. 40.3%, OR=1.13, 95% CI 0.78-1.65, P=0.51, respectively],though a reduced YMDD mutation rate was achieved in the combination group [8.39% vs. 30.0%, OR=0.16, 95% CI 0.076-0.33, P<0.001]. However, data from one PEG-IFN trial showed greater sustained virological and biochemical rates in patients receiving combination therapy [response rate 19.5% vs. 6.6%, OR=3.42, 95% CI 1.71-6.84, P<0.001 and 60.0% vs. 44.2%, OR=1.88, 95% CI 1.23-2.85, P=0.003, respectively]. CONCLUSIONS: Addition of CON-IFN to lamivudine did not improve treatment efficacy but suppressed YMDD mutation by lamivudine. Combination of PEG-IFN and lamivudine might increase the sustained response, and further clinical trials are needed for confirmation.

Current and future antiviral drug therapies of hepatitis B chronic infection

Despite significant improvement in the management of chronic hepatitis B virus(HBV) it remains a public health problem, affecting more than 350 million people worldwide. The natural course of the infection is dynamic and involves a complex interplay between the virus and the host's immune system. Currently the approved therapeutic regimens include pegylated-interferon(IFN)-α and monotherapy with five nucleos(t)ide analogues(NAs). Both antiviral treatments are not capable to eliminate the virus and do not establish long-term control of infection after treatment withdrawal. IFN therapy is of finite duration and associates with low response rates, liver decompensating and numerous side effects. NAs are well-tolerated therapies but have a high risk of drug resistance development that limits their prolonged use. The imperative for the development of new approaches for the treatment of chronic HBV infection is a challenging issue that cannot be over-sided. Research efforts are focusing on the identification and evaluation of various viral replication inhibitors that target viral replication and a number of immunomodulators that aim to restore the HBV specific immune hyporesponsiveness without inducing liver damage. This review brings together our current knowledge on the available treatment and discusses potential therapeutic approaches in the battle against chronic HBV infection.

Detection of hyper-conserved regions in hepatitis B virus X gene potentially useful for gene therapy

AIM To detect hyper-conserved regions in the hepatitis B virus(HBV) X gene(HBX) 5' region that could be candidates for gene therapy.METHODS The study included 27 chronic hepatitis B treatmentnaive patients in various clinical stages(from chronic infection to cirrhosis and hepatocellular carcinoma, both HBeA g-negative and HBeA g-positive), and infected with HBV genotypes A-F and H. In a serum sample from each patient with viremia > 3.5 log IU/m L, the HBX 5' end region [nucleotide(nt) 1255-1611] was PCRamplified and submitted to next-generation sequencing(NGS). We assessed genotype variants by phylogenetic analysis, and evaluated conservation of this region by calculating the information content of each nucleotide position in a multiple alignment of all unique sequences(haplotypes) obtained by NGS. Conservation at the HBx protein amino acid(aa) level was also analyzed.RESULTS NGS yielded 1333069 sequences from the 27 samples, with a median of 4578 sequences/sample(2487-9279, IQR 2817). In 14/27 patients(51.8%), phylogenetic analysis of viral nucleotide haplotypes showed a complex mixture of genotypic variants. Analysis of the information content in the haplotype multiple alignments detected 2 hyper-conserved nucleotide regions, one in the HBX upstream non-coding region(nt 1255-1286) and the other in the 5' end coding region(nt 1519-1603). This last region coded for a conserved amino acid region(aa 63-76) that partially overlaps a Kunitz-like domain.CONCLUSION Two hyper-conserved regions detected in the HBX 5' end may be of value for targeted gene therapy, regardless of the patients' clinical stage or HBV genotype.

Immune therapy including dendritic cell based therapy in chronic hepatitis B virus infection

Hepatitis B virus （HBV） infection is a global public health problem. Of the approximately 2 billion people who have been infected worldwide, more than 400 million are chronic carriers of HBV. Considerable numbers of chronic HBV carriers suffer from progressive liver diseases. In addition, all HBV carriers are permanent source of this virus. There is no curative therapy for chronic HBV carriers. Antiviral drugs are recommended for about 10% patients, however, these drugs are costly, have limited efficacy, and possess considerable side effects. Recent studies have shown that immune responses of the host to the HBV are critically involved at every stage of chronic HBV infection： （1） These influence acquisition of chronic HBV carrier state, （2） They are important in the context of liver damages, （3） Recovery from chronic HBV-related liver diseases is dependent on nature and extent of HBV-specific immune responses. However, induction of adequate levels of HBV-specific immune responses in chronic HBV carriers is difficult. During the last one decade, hepatitis B vaccine has been administered to chronic HBV carriers as a therapeutic approach （vaccine therapy）. The present regimen of vaccine therapy is safe and cheap, but not so effective. A dendritic cell-based therapeutic vaccine has recently been developed for treating chronic HBV infection. In this review, we will discuss about the concept, scientific logics, strategies and techniques of development of HBV- specific immune therapies including vaccine therapy and dendritic cell-based vaccine therapy for treating chronic HBV infection.

WJG 20^(th) Anniversary Special Issues(1): Hepatocellular carcinoma Risk prediction of hepatitis B virus-related hepatocellular carcinoma in the era of antiviral therapy

Chronic hepatitis B(CHB)-related hepatocellular carcinoma(HCC)is a major health problem in AsianPacific regions.Antiviral therapy reduces,but does not eliminate the risk of HCC.It would be a heavy financial burden in most low and middle economic countries if all CHB patients received antiviral therapy and HCC surveillance.Thus,there is a need for accurate risk prediction to assist prognostication,decisions on the need for antiviral therapy and HCC surveillance.A few wellestablished risk factors for HCC,namely advanced age,male gender,high viral load,cirrhosis etc.,are the core components of three HCC risk scores:CU-HCC,GAGHCC and REACH-B scores.These 3 scores were confirmed to be accurate in predicting HCC up to 10 years in treatment-na ve patients.Their validity and applicability have recently been demonstrated in a large cohort of entecavir treatment patients.A decrease in risk scores after antiviral therapy translates to a lower risk of HCC.These findings support the application of HCC risk scores in all CHB patients.Different levels of care and different intensities of HCC surveillance should be offered according to the risk profile of patients.Patients at risk of HCC should undergo regular HCC surveillance,even when they are receiving antiviral treatment.