Long-term therapy of chronic hepatitis B with lamivudine

Application of the woodchuck animal model for the treatment of hepatitis B virus-induced liver cancer

This review describes woodchucks chronically infected with the woodchuck hepatitis virus (WHV) as an animal model for hepatocarcinogenesis and treatment of primary liver cancer or hepatocellular carcinoma (HCC) induced by the hepatitis B virus (HBV). Since laboratory animal models susceptible to HBV infection are limited, woodchucks experimentally infected with WHV, a hepatitis virus closely related to HBV, are increasingly used to enhance our understanding of virus-host interactions, immune response, and liver disease progression. A correlation of severe liver pathogenesis with high-level viral replication and deficient antiviral immunity has been established, which are present during chronic infection after WHV inoculation of neonatal woodchucks for modeling vertical HBV transmission in humans. HCC in chronic carrier woodchucks develops 17 to 36 mo after neonatal WHV infection and involves liver tumors that are comparable in size, morphology, and molecular gene signature to those of HBV-infected patients. Accordingly, woodchucks with WHV-induced liver tumors have been used for the improvement of imaging and ablation techniques of human HCC. In addition, drug efficacy studies in woodchucks with chronic WHV infection have revealed that prolonged treatment with nucleos(t)ide analogs, alone or in combination with other compounds, minimizes the risk of liver disease progression to HCC. More recently, woodchucks have been utilized in the delineation of mechanisms involved in innate and adaptive immune responses against WHV during acute, self-limited and chronic infections. Therapeutic interventions based on modulating the deficient host antiviral immunity have been explored in woodchucks for inducing functional cure in HBV-infected patients and for reducing or even delaying associated liver disease sequelae, including the onset of HCC. Therefore, woodchucks with chronic WHV infection constitute a well-characterized, fully immunocompetent animal model for HBV-induced liver cancer and for preclinical evaluation of the safety and efficacy of new modalities, which are based on chemo, gene, and immune therapy, for the prevention and treatment of HCC in patients for which current treatment options are dismal.

Rapid Turnover of Hepatitis B Virus Covalently Closed Circular DNA Indicated by Monitoring Emergence and Reversion of Signature-Mutation in Treated Chronic Hepatitis B Patients

BACKGROUND AND AIMS

Hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) plays a pivotal role in the establishment and persistence of HBV infection. Understanding the turnover time of preexisting cccDNA pools would be helpful in designing strategies to clear HBV by fully blocking the de novo generation of cccDNA.

APPROACH AND RESULTS

In this study, we retrospectively monitored the emergence and reversion of the rtM204I/V mutant, a signature lamivudine resistance (LAMR ) mutation serving as a biomarker of cccDNA turnover in liver biopsies and longitudinal serum samples from two clinical trials. Methodologies were optimized to differentially isolate and sequence HBV virion DNA, cccDNA, and HBV RNA from clinical samples. A strong correlation was observed between LAMR composition of cccDNA with that of serum and intrahepatic HBV RNA in paired liver and serum samples (r = 0.96 and 0.90, respectively), suggesting that serum HBV RNA can serve as a surrogate marker of cccDNA genetic composition when liver biopsies are unavailable. LAMR mutations emerged and increased from undetectable to 40%-90% within 16-28 weeks in serum HBV RNA from telbivudine-treated patients experiencing virological breakthrough. Similarly, in lamivudine-resistant patients who switched to interferon therapy, serum HBV-RNA population bearing 100% LAMR mutations fully reversed back to wild type within 24-48 weeks.

CONCLUSIONS

The genetic composition dynamics of serum HBV RNA and biopsy cccDNA in treated HBV patients indicates that cccDNA turnover occurs relatively rapidly (several months), offering a possibility of HBV cure with finite therapy through completely blocking cccDNA replenishment.

Hepatitis B-related glomerulonephritis and optimization of treatment

Introduction: Multiple studies have revealed a strong relationship between the development of nephropathy and hepatitis B virus (HBV) infection. The underlying pathogenesis of hepatitis B-related glomerulonephritis (HBV-GN) involves immune complexes, which can be isolated from kidney tissues. Clearance of HBV antigenemia improves renal impairment and proteinuria in HBV-GN patients.Areas covered: In this review, we present our current understanding of the epidemiology, pathogenesis, pathology, diagnosis, and treatment of HBV-GN. We discuss the advantages and disadvantages of oral nucleoside/nucleotide analogs (NAs), and the main pharmaceutical treatment for hepatis B.Expert opinion: Currently, antiviral agents are the main HBV-GN therapeutic agents. Although no randomized controlled clinical trials have compared the efficacy of interferon (IFN) and NA, we suggest IFN treatment for pediatric patients (IFN-α in patients ≥1 year; pegIFN-α in patients ≥3 years) considering treatment duration and absence of resistance. Novel NAs have brought about promising treatment options involving high efficacy viral suppression and low resistance rates. NAs with a high barrier to resistance (e.g. entecavir) are recommended as first-line therapy of HBV-GN. Immunosuppression monotherapy, such as corticosteroids, is of little benefit and potentially harmful to HBV-GN patients due to the possibility of viral reactivation.

Adverse events of nucleos(t)ide analogues for chronic hepatitis B: a systematic review

Nucleos(t)ide analogues (NAs) are the main drug category used in chronic hepatitis B (CHB) treatment. Despite the fact that NAs have a favourable safety profile, undesired adverse events (AEs) may occur during the treatment of CHB. Given the eminent number of patients currently receiving NAs, even a small risk of any of these toxicities can represent a major medical issue. The main objective of this review was to analyse information available on AEs associated with the use of NAs in published studies. We choose the following MesH terms for this systematic review: chronic hepatitis B, side effects and treatment. All articles published from 1 January 1990 up to 19 February 2018 in MEDLINE of PubMed, EMBASE, the Cochrane Library and LILACS databases were searched. A total of 120 articles were selected for analysis, comprising 6419 patients treated with lamivudine (LAM), 5947 with entecavir (ETV), 3566 with tenofovir disoproxil fumarate (TDF), 3096 with telbivudine (LdT), 1178 with adefovir dipivoxil (ADV) and 876 with tenofovir alafenamide (TAF). The most common AEs in all NAs assessed were abdominal pain/discomfort, nasopharyngitis/upper respiratory tract infections, fatigue, and headache. TAF displays the highest density of AEs per patient treated among NAs (1.14 AE/treated patient). In conclusion, treatment of CHB with NAs is safe, with a low incidence of AEs. Despite the general understanding TAF being safer than TDF, the number of patients treated with TAF still is too small in comparison to other NAs to consolidate an accurate safety profile. PROSPERO Registration No. CRD42018086471.

The Removal of HBV in Plasma by Extracorporeal Immunoadsorption from Plasma: A Potential Therapy of Hepatitis B Patients

Objective

To establish a novel HBV specific immunoadsorbent for the removing of HBV particles.

Methods

The anti-HBsAg monoclonal antibody was immobilized on sepharose beads to produce a sepharose anti-HBs column. Then the immunoadsorbent was evaluated and characterized by scanning electron microscopy. In addition, time-dependent effects of the eradication capacity of anti-HBsAg functionalized sepharose beads against HBV were investigated.

Results

Proposed immunoadsorbents exhibited a favorable biocompatibility as well as specificity. With the optimized recycle time, the decontamination performance of HBV particles and quantity of HBsAg were assessed either by real-time quantitative PCR or ELISA, which showed that the immunoadsorbent could remove approximately 90% of the HBV and 90% of the HBsAg from human plasma samples.

Conclusions

All these results indicated that the novel immunoadsorbent could effectively remove HBV particles and likely serve as a novel therapy option or at least supplementary for the treatment regimen of HBV.

Prophylactic effect of lamivudine on chemotherapy-induced hepatitis B virus reactivation in patients with solid tumour: A meta-analysis

Hepatitis B virus (HBV) reactivation is a remarkable risk during the chemotherapy for solid tumour patients. Nucleos(t)ide analogues (NAs) are recommended as prophylaxis for the reactivation of HBV infection in some cancer patients prior to systemic chemotherapy. Therefore, we performed a meta-analysis aiming to determine the efficacy of prophylactic lamivudine on prevention of HBV reactivation and its related negative outcomes among solid tumour patients with chronic HBV infection receiving systemic chemotherapy. The primary outcome was HBV reactivation, and the secondary outcomes were HBV-related hepatitis, chemotherapy disruption, mortality and tyrosine-methio-nine-aspartate-aspartate (YMDD) mutations. Twelve original researches involving 1,101 patients were analysed in this study. The relative risk of HBV reactivation in patients with lamivudine prophylaxis was significantly lower than that without prophylaxis (RR = 0.17, 95% CL: 0.10-0.29, p < .00001). Lamivudine prophylaxis reduced the relative risk of hepatitis (p < .00001), chemotherapy disruptions (p = .01) and mortality (p = .08) due to HBV reactivation. Lamivudine prophylaxis is effective in reducing HBV reactivation and its related negative outcomes, such as hepatitis and chemotherapy disruption and mortality among chemotherapeutic solid tumour patients with chronic HBV infection. Future studies should lay more emphasis on the early HBV screening, mode of treatment and duration of NAs prophylaxis among solid tumour patients receiving chemotherapy.

Factors Associated With Persistent Increase in Level of Alanine Aminotransferase in Patients With Chronic Hepatitis B Receiving Oral Antiviral Therapy

BACKGROUND & AIMS

Despite complete suppression of viral DNA with antiviral agents, in some patients with chronic hepatitis B (CHB), serum levels of alanine aminotransferase (ALT) do not normalize. We investigated factors associated with persistent increases in ALT level in patients with CHB given long-term tenofovir disoproxil fumarate.

METHODS

We analyzed data from 471 hepatitis B e antigen (HBeAg)-positive and HBeAg-negative patients with CHB participating in 2 phase 3 trials. We identified patients with an increased level of ALT (above the upper limit of normal range) after 5 years (240 weeks) of tenofovir disoproxil fumarate therapy. We analyzed findings from liver biopsy specimens collected from 467 patients (99%) at baseline and 339 patients (72%) at year 5 of treatment; biopsy specimens were evaluated by an independent pathologist. We performed stepwise, forward, multivariate regression analyses of specified baseline characteristics and on-treatment response parameters to identify factors associated with persistent increases in ALT level.

RESULTS

Of the 471 patients, 87 (18%) still had an increased ALT level at year 5 of treatment. Factors associated significantly with a persistent increase in ALT level were a steatosis score of 5% or greater (grade 1 or more) at baseline (odds ratio [OR], 2.236; 95% confidence interval [CI], 1.031-4.852; P = .042) and at year 5 (OR, 3.392; 95% CI, 1.560 ≥ 7.375; P = .002), HBeAg seropositivity at baseline (OR, 3.297; 95% CI, 1.653-6.576; P < .001), and age 40 years or older (OR, 2.099; 95% CI, 1.014-4.342; P = .046). Of the 42 HBeAg-positive patients with steatosis at baseline, 21 (50%) had an increased ALT level at year 5 of treatment. Patients with persistent increases in ALT level were more likely to have an increase in steatosis at year 5 than those with a normal ALT level.

CONCLUSIONS

HBeAg seropositivity and hepatic steatosis contribute to persistent increases in ALT level in patients with CHB receiving suppressive antiviral treatment. ClinicalTrials.gov registration numbers: NCT00117676 and NCT00116805.

In-host modeling

Understanding the mechanisms governing host-pathogen kinetics is important and can guide human interventions. In-host mathematical models, together with biological data, have been used in this endeavor. In this review, we present basic models used to describe acute and chronic pathogenic infections. We highlight the power of model predictions, the role of drug therapy, and advantage of considering the dynamics of immune responses. We also present the limitations of these models due in part to the trade-off between the complexity of the model and their predictive power, and the challenges a modeler faces in determining the appropriate formulation for a given problem.

Long-term lamivudine therapy in chronic hepatitis B

BACKGROUND

One to 5 years of therapy of chronic hepatitis B with oral nucleoside analogues result in significant clinical improvements, but effects of more prolonged therapy are not well defined.

AIM

To describe outcomes of chronic hepatitis B with long-term lamivudine therapy.

METHODS

Forty-two patients with chronic hepatitis B treated with lamivudine were followed for 3.2-19.5 (median = 16.1) years. Therapy was switched to other agents (n = 16) if patients developed lamivudine resistance and relapse of disease.

RESULTS

Among 22 HBeAg-positive patients, 17 (77%) became HBeAg negative, of whom 5 (23%) subsequently cleared HBsAg. Among 20 HBeAg-negative patients, 10 (50%) cleared HBsAg. The time to HBsAg clearance ranged from 0.9 to 16.8 (median = 9.3) years. Lamivudine resistance arose in 24 patients (57%) of whom 6 (25%) lost HBsAg. HBsAg clearance was not always accompanied by seroconversion; anti-HBs appearing concurrently in only five patients (33%). Nevertheless, HBsAg loss allowed for stopping therapy in all patients, none re-developing HBsAg or suffering relapse; all having normal alanine aminotransferase levels and no (n = 13) or unquantifiable HBV DNA levels (n = 2) when last seen. In contrast, seven of 27 patients (26%) who remained HBsAg-positive died of liver disease or liver cancer or underwent liver transplantation, all of whom had cirrhosis.

CONCLUSIONS

Long-term viral suppression with nucleoside analogues leads to HBsAg loss in a substantial proportion of patients, particularly if HBeAg-negative. Serious outcomes during the first 10-20 years of treatment occur largely among patients with pre-existing cirrhosis who do not clear HBsAg with therapy.

The suppressive effect of nucleos(t)ide analogue treatment on the incidence of hepatocellular carcinoma in chronic hepatitis B patients

The development of nucleos(t)ide analogues (NA) has influenced hepatitis B virus management. However, the annual incidence rate during NA treatment has been reported to be 0.3-1.2% in non-cirrhosis cases and 1.8-6.0% in cirrhosis cases, indicating that the suppressive effect of NA treatment on hepatocellular carcinoma (HCC) would be insufficient. Past studies, including one randomized control trial that compared lamivudine treatment with placebo, have revealed that NA treatment could suppress the incidence of HCC in patients with advanced fibrosis. However, it remains unknown whether NA treatment can suppress the incidence of HCC in chronic hepatitis patients without advanced fibrosis. The HCC incidence in patients treated with entecavir was similar to that of those treated with lamivudine, although entecavir exhibits a stronger viral suppression than lamivudine. The following risk factors related to the incidence of HCC during NA treatment have been identified: older age, male gender, pre-existing cirrhosis, a family clustering of hepatitis B virus, lower platelet counts, and higher hepatitis B core-related antigens as baseline factors and higher alpha fetoprotein levels as an on-treatment factor. Conversely, the loss of the hepatitis B surface antigen (HBsAg) by interferon or NA was correlated with a lower HCC incidence rate. Because interferon treatment has much more effects on reducing HBsAg levels compared with NA treatment, a combination treatment with NA and pegylated interferon can bring additional reduction of HBsAg levels compared with NA monotherapy. Further study is needed to clarify this.

Identification of the transcriptional regulators by expression profiling infected with hepatitis B virus

BACKGROUND

The molecular pathogenesis of infection by hepatitis B virus with human is extremely complex and heterogeneous. To date the molecular information is not clearly defined despite intensive research efforts. Thus, studies aimed at transcription and regulation during virus infection or combined researches of those already known to be beneficial are needed.

AIMS

With the purpose of identifying the transcriptional regulators related to infection of hepatitis B virus in gene level, the gene expression profiles from some normal individuals and hepatitis B patients were analyzed in our study.

METHODS

In this work, the differential expressed genes were selected primarily. The several genes among those were validated in an independent set by qRT-PCR. Then the differentially co-expression analysis was conducted to identify differentially co-expressed links and differential co-expressed genes. Next, the analysis of the regulatory impact factors was performed through mapping the links and regulatory data. In order to give a further insight to these regulators, the co-expression gene modules were identified using a threshold-based hierarchical clustering method. Incidentally, the construction of the regulatory network was generated using the computer software.

RESULTS

A total of 137,284 differentially co-expressed links and 780 differential co-expressed genes were identified. These co-expressed genes were significantly enriched inflammatory response. The results of regulatory impact factors revealed several crucial regulators related to hepatocellular carcinoma and other high-rank regulators. Meanwhile, more than one hundred co-expression gene modules were identified using clustering method.

CONCLUSIONS

In our study, some important transcriptional regulators were identified using a computational method, which may enhance the understanding of disease mechanisms and lead to an improved treatment of hepatitis B. However, further experimental studies are required to confirm these findings.

Liver transplantation for viral hepatitis in 2015

Liver transplantation (LT) is a life-saving treatment for patients with end-stage liver disease and for patients with liver cell cancer related to liver disease. Acute and chronic liver diseases related to hepatitis viruses are between the main indications for liver transplantation. The risk of viral reinfection after transplantation is the main limiting factor in these indications. Before the availability of antiviral prophylaxis, hepatitis B virus (HBV) recurrence was universal in patients who were HBV DNA-positive before transplantation. The natural history of recurrent HBV was accelerated by immunosuppression, and it progressed rapidly to graft failure and death. Introduction of post-transplant prophylaxis with immunoglobulin alone first, and associated to antiviral drugs later, drastically reduced HBV recurrence, resulting in excellent long-term outcomes. On the contrary, recurrence of hepatitis C is the main cause of graft loss in most transplant programs. Overall, patient and graft survival after LT for hepatitis C virus (HCV)-associated cirrhosis is inferior compared with other indications. However, successful pretransplant or post transplant antiviral therapy has been associated with increased graft and overall survival. Until recently, the combination of pegylated interferon and ribavirin was the standard of care for the treatment of patients with chronic hepatitis C. Highly active antiviral compounds have been developed over the past decade, thanks to new in vitro systems to study HCV entry, replication, assembly, and release.

Backs against the wall: novel and existing strategies used during the 2014-2015 Ebola virus outbreak

The 2014-2015 outbreak of Ebola virus (EBOV), originating from Guinea, is now responsible for the infection of >20,000 people in 9 countries. Whereas past filovirus outbreaks in sub-Saharan Africa have been rapidly brought under control with comparably few cases, this outbreak has been particularly resistant to containment efforts. Both the general population and primary health care workers have been affected by this outbreak, with hundreds of doctors and nurses being infected in the line of duty. In the absence of approved therapeutics, several caregivers have turned to investigational new drugs as well as experimental therapies in an effort to save lives. This review aims to summarize the candidates currently under consideration for postexposure use in infected patients during the largest EBOV outbreak in history.

Prophylactic Effect of Lamivudine for Chemotherapy-Induced Hepatitis B Reactivation in Breast Cancer: A Meta-Analysis

Background

Three strategies using lamivudine have been proposed to prevent chemotherapy-induced HBV (hepatitis B virus) reactivation in the clinical setting. The purpose of this meta-analysis is to evaluate the efficacy of the early preemptive strategy, deferred preemptive strategy and therapeutic strategy in patients with HBsAg-positive breast cancer during chemotherapy.

Methods

Clinical studies published from database inception until Nov 1, 2014, were included for analysis. The primary outcomes were overall survival, rate of chemotherapy disruption and virological and clinical reactivation. The secondary outcomes were the rates of HBV-related chemotherapy disruption, HBV-related mortality, YMDD mutations and withdrawal hepatitis.

Results

Four hundred and thirty patients in four studies that compared the early preemptive strategy with a therapeutic strategy were included. Application of early preemptive lamivudine was superior in reducing HBV recurrence (pooled OR: 0.12, 95% CI, 0.04 to 0.31, P< 0.0001), the incidence of HBV-related hepatitis (pooled OR: 0.13, 95% CI, 0.04 to 0.37, P< 0.0001) and the rate of chemotherapy disruption (pooled OR: 0.37, 95% CI, 0.23 to 0.60, P< 0.0001). In these two groups, no significant difference was found in overall mortality (P = 0.32), YMDD mutant rate (P = 0.13) or incidence of withdrawal hepatitis (P = 0.38). Of the two studies that compared the efficacy of an early and a deferred preemptive strategy, one showed that an early preemptive strategy significantly reduced the incidence of hepatitis (P = 0.046), whereas the other showed no significant difference (P = 0.7).

Conclusions

An early preemptive strategy is superior to a therapeutic strategy in decreasing the incidence of HBV reactivation, incidence of HBV-related hepatitis and rate of chemotherapy disruption in patients with breast cancer. A deferred preemptive strategy might be an alternative approach to controlling viral replication.

Prophylactic lamivudine to improve the outcome of HBsAg-positive lymphoma patients during chemotherapy: a systematic review and meta-analysis

Hepatitis B viral (HBV) reactivation in lymphoma patients undergoing chemotherapy is associated with significant morbidity and mortality. Increasingly, lamivudine is being used to prevent hepatitis B reactivation. To assess the effects of prophylactic lamivudine on reactivation and mortality following chemotherapy in lymphoma patients who are hepatitis B surface antigen (HBsAg)-positive, we searched Medline/PubMed, Ovid MEDLINE, EMBASE, Web of Knowledge and the Cochrane Library for studies through November 2013. Statistical analysis was performed using REVMAN. Fourteen studies consisting of 636 patients were included in the analysis. The rate of HBV reactivation, incidence of hepatitis and incidence of hepatitis due to HBV reactivation in patients with lamivudine prophylaxis was significantly lower than those with no prophylaxis. Risk ratios [RRs] were 0.25 (95% confidence intervals [CI] 0.13-0.51; P=0.0001), 0.40 (95% CI 0.26-0.63; P<0.0001), and 0.21 (95% CI 0.09-0.51; P=0.0005) respectively. In addition, patients given prophylactic lamivudine had significant reductions in overall mortality and mortality attributable to HBV reactivation compared with control group. Risk ratios [RRs] were 0.45 (95% CI 0.29-0.70; P=0.0004) and 0.41 (95% CI 0.20-0.84; P=0.01) respectively. Chemotherapy disruption was not significantly different between the two groups. Risk ratios [RRs] were 0.34 (95% CI 0.09-1.26; P=0.11). Prophylactic therapy with lamivudine for HBsAg-positive lymphoma patients who are undergoing chemotherapy may reduce the risk for HBV reactivation, hepatitis due to HBV reactivation, overall mortality and mortality attributable to HBV reactivation. Additionally, patients with preventive lamivudine had a trend towards the decreased incidence of chemotherapy disruption.

Recent advances in micro/nanotechnologies for global control of hepatitis B infection

The control of hepatitis B virus (HBV) infection is a challenging task, specifically in developing countries there is limited access to diagnostics and antiviral treatment mainly due to high costs and insufficient healthcare infrastructure. Although the current diagnostic technologies can reliably detect HBV, they are relatively laborious, impractical and require expensive resources that are not suitable for resource-limited settings. Advances in micro/nanotechnology are pioneering the development of new generation methodologies in diagnosis and screening of HBV. Owing to combination of nanomaterials (metal/inorganic nanoparticles, carbon nanotubes, etc.) with microfabrication technologies, utilization of miniaturized sensors detecting HBV and other viruses from ultra-low volume of blood, serum and plasma is realized. The state-of-the-art microfluidic devices with integrated nanotechnologies potentially allow for inexpensive HBV screening at low cost. This review aims to highlight recent advances in nanotechnology and microfabrication processes that are employed for developing point-of-care (POC) HBV assays.

Partial virological response to three different nucleotide analogues in naive patients with chronic hepatitis B

BACKGROUND

The definition of partial virological response (PVR) was proposed because of its clinical relevance. PVR relates to subsequent therapeutic failure which results in the modification of the regimen. Whether this rationale can be applied to all nucleotide analogues (NA) is not clear. This study was undertaken to analyze PVR influence on therapeutic outcomes during lamivudine, entecavir or tenofovir monotherapy in NA-naive patients with chronic hepatitis B in routine clinical practice.

METHODS

We retrospectively analyzed 150 NA-naive patients with chronic hepatitis B. These subjects received lamivudine, entecavir or tenofovir monotherapy between February 2001 and July 2013.

RESULTS

Sixty-nine patients were treated with lamivudine, 35 with entecavir, and 46 with tenofovir. The median therapeutic duration was 19.5 (6-147) months. PVR rates at 24 weeks were similar among three NAs (lamivudine 33.3%, entecavir 35.0%, tenofovir 32.4%, P=0.981). For all three NAs, patients with a higher baseline viral load or HBeAg-positive status had a higher serum viral positive rate tested by polymerase chain reaction at week 24 and 48. Cumulative probability of virological breakthrough (VBR) for patients treated with lamivudine was 67% at 5 years, and PVR at 24 weeks was the independent risk factor for VBR (HR: 3.09; 95% CI: 1.09-8.74; P=0.034); also lamivudine treated patients older than 50 years seemed to have a tendency for VBR (HR: 2.80; 95% CI: 0.99-8.18; P=0.052). A majority of entecavir and tenofovir partial responders achieved and maintained virological response with prolonged monotherapy, except one entecavir treated patient who experienced VBR due to resistance mutations.

CONCLUSIONS

Management strategy for lamivudine treatment should include adaptation of regimen according to PVR as an on-treatment response parameter due to its relation with unacceptably high VBR probability. Similar conclusion should not be directly related to entecavir or tenofovir treatment.

Lamivudine treatment and outcome in pregnant women with high hepatitis B viral loads

Perinatal transmission is the most common mode of hepatitis B virus (HBV) transmission and is a leading cause of chronic infection worldwide. Maternal treatment with lamivudine (LAM) can result in a rapid and significant reduction in HBV viral load (VL) and, thus, mitigate the risk of mother-to-child transmission (MTCT). The aim of this study was to retrospectively evaluate the safety of LAM treatment administered in the third trimester of pregnancy and determine the influence, if any, on infant outcome. The medical charts of all HBV surface antigen (HBsAg)-positive women eligible for treatment with LAM and who registered for antenatal care between 2007 and 2012 were retrospectively reviewed. During the 6-year period, 45 women met the criteria for LAM treatment. Thirty-six women (80 %) accepted treatment; the remaining women declined treatment (5), defaulted from care (3) or transferred to another maternity unit (1). The median duration of treatment was 11.4 weeks (range 5.3-17.4) and the median baseline VL was 1.4 × 10(8) IU/mL (range 1.8 × 10(7)-1.7 × 10(8)). The median VL at delivery was 2.3 × 10(5) IU/mL and 60 % of women achieved a VL reduction >2 log10 IU/mL before delivery. No cases of perinatal transmission occurred in the infants born to mothers who received treatment; however, one infant, born to a mother who defaulted from care, was HBV-infected at 8 months. The results suggest that LAM therapy in highly viraemic HBV-infected pregnant women could lower the rate of vertical transmission.

Prediction of prognosis to lamivudine in patients with spontaneous reactivation of hepatitis B virus-related acute-on-chronic liver failure: using virologic response at week 4

BACKGROUND/AIMS

Current results had demonstrated lamivudine (LAM) contributed to improve liver function and short-term prognosis in patients with hepatitis B virus-related acute-on-chronic liver failure (ACLF), but data concerning the outcome of long-term prognosis are limited. Our objective was to explore the prediction value of early viral response for prognosis and LAM resistance in ACLF patients with lamivudine treatment within 96weeks.

METHODS

One hundred and forty consecutive subjects were recruited, 76 patients were treated with LAM and supportive treatment (LAM group) and 64 patients only received supportive treatment (non-NAs group). All the patients were followed up until death or 96weeks. The primary end point was overall survival rate at 96weeks, as well as the relationship between the virologic response at weeks 4 or 12 and prognosis and resistance at 96weeks.

RESULTS

At 96weeks, the cumulative survival was higher in the LAM group than that in the non-NA group (43/76 (56.58%) vs 9/64 (14.06%), respectively, p=0.000). The survival rate of patients achieved complete viral response (CVR) at week 4 was higher than that of those with partial virologic response (PVR) during the 96-week follow-up (27/29 [93.10%] vs 16/45 [35.56%], p=0.000). In CVR patients, there was a significant improvement in model for end-stage liver failure (MELD) scores compared to PVR. Logistic recurrence indicated that both 4-week CVR and MELD scores were an independent predictor of the 96-week survival. Twelve patients developed LAM resistance (22.22%); all of them came from the PVR at 4weeks.

CONCLUSION

LAM can significantly improve the long-term survival rate, and 4weeks CVR can predict the long-term clinical outcome and LAM-resistant in patients with HBV-related ACLF.

Acute exacerbation of chronic hepatitis B virus infection in renal transplant patients

INTRODUCTION

There is scarce information regarding clinical evolution of HBV infection in renal transplant patients.

AIMS

To evaluate the prevalence of acute exacerbation in HBV-infected renal transplant patients and its association with the time after transplantation, presence of viral replication, clinical evolution, and use of antiviral prophylaxis.

MATERIALS AND METHODS

HBV infected renal transplant patients who underwent regular follow-up visits at 6-month intervals were included in the study. The criteria adopted to characterize exacerbation were: ALT >5× ULN and/or >3× baseline level. Predictive factors of exacerbation evaluated were age, gender, time on dialysis, type of donor, post-transplant time, ALT, HBeAg, HBV-DNA, HCV-RNA, immunosuppressive therapy, and use of antiviral prophylaxis.

RESULTS

140 HBV-infected renal transplant patients were included (71% males; age 46 ± 10 years; post-renal transplant time 8 ± 5 years). During follow-up, 25% (35/140) of the patients presented exacerbation within 3.4 ± 3 years after renal transplant. Viral replication was observed in all patients with exacerbation. Clinical and/or laboratory signs of hepatic insufficiency were present in 17% (6/35) of the patients. Three patients died as a consequence of liver failure. In univariate analysis variables associated with exacerbation were less frequent use of prophylactic/preemptive lamivudine and of mycophenolate mofetil. Lamivudine use was the only variable independently associated with exacerbation, with a protective effect.

CONCLUSIONS

Acute exacerbation was a frequent and severe event in HBV-infected renal transplant patients. Prophylactic/preemptive therapy with antiviral drugs should be indicated for all HBsAg-positive renal transplant patients.

Effect of prophylactic versus preemptive lamivudine treatment and tenofovir on HBsAg+ kidney transplant recipients

OBJECTIVES

Chronic hepatitis B virus infection remains a clinical problem for HBsAg (+) kidney transplant recipients. Lamivudine is the approved treatment; however, there are contrary views about optimal initiation. In case of resistance, novel nucleoside analogs should be considered but experience is limited.

MATERIALS AND METHODS

The study was a retrospective cohort study that included 58 HBsAg (+) kidney transplant recipients. Medical records were reviewed for nucleoside analogs, viral replication, and graft/hepatic functions. Prophylactic and preemptive lamivudine modalities were compared to reveal optimal initiation. Additionally, novel nucleoside analogs were evaluated for safety and efficacy.

RESULTS

The graft/patient survival rates for HBsAg (+) recipients were the same as those of hepatitis-free recipients (P = .18). Prophylactic group had 24 and the preemptive had 34 patients. In the prophylactic group, there were fewer hepatic dysfunctions (12.5% vs. 30%, P = .12), viral breakthroughs (16% vs. 32%, P = .17) and elevated alanine aminotransferase concentrations (37% vs. 52%, P = .24), however these did not reach statistical significance. Progressive hepatic dysfunction was observed in 5 patients. Treatment was altered to tenofovir (n = 4) and adefovir (n = 1), and adequate virologic/biochemical response was achieved. These nucleoside analogs were almost as safe as lamivudine, as there were no significant differences among proteinuria (4740 ± 9480 vs 1250 ± 430 mg/L; P = .60) and estimated glomerular filtration rate (1.23 ± 0.37 vs 1.10 ± 0.35 mL/s; P = .33) CONCLUSIONS: Lamivudine is an efficient means of providing comparable graft/patient survival with hepatitis-free kidney transplant recipients. The prophylactic initiation of lamivudine may be better in preventing hepatic dysfunction. Tenofovir can be an effective and safe treatment for lamivudine-resistant kidney transplant recipients.

Effect of matrine on primary human hepatocytes in vitro

Matrine is a bioactive component of the traditional Chinese medical herb Sophora flavescens that has been used in China to treat various kinds of diseases including virus hepatitis. However, the molecular mechanisms underlying its hepatoprotective effects remains elusive. In the present study, primary human hepatocytes were employed to elucidate the protective effects and molecular mechanisms of matrine. We observed that low concentrations of matrine had no significant impact on albumin secretion, but high concentrations (>140 mg/L) of matrine decreased the albumin secretion in hepatocytes. Western blot data indicated that matrine at 140 mg/L at 72 h induced protein expression of CYP2A6, CYP2B6 and CYP3A4. Furthermore, high concentrations of matrine reduced LDH and AST levels and were cytotoxic to hepatocytes, leading to a decreased cell viability and total protein amount. Moreover, low concentrations of matrine, enhanced the ECOD activity and decreased the level of NO2 (-) induced by cytokines in human hepatocytes. Taken together, the present study sheds novel light on the molecular mechanisms of matrine and potential application of matrine in hepatic diseases.

Clinical utility of entecavir for chronic hepatitis B in Chinese patients

The People's Republic of China has one of the highest rates of hepatitis B virus (HBV) infection. This review summarizes recent data from studies of entecavir, one of the recommended first-line oral therapies for treating chronic hepatitis B, in Chinese HBV-infected patients. Long-term treatment with entecavir is efficacious and well tolerated, and studies comparing entecavir with other nucleos(t)ide therapies, such as lamivudine, adefovir, and telbivudine, demonstrate superior antiviral effects for entecavir therapy and comparable safety profiles. Entecavir monotherapy and combination treatment with other nucleos(t) ide analogs has been shown to be efficacious in the treatment of lamivudine-resistant and adefovir-resistant patients with HBV infection, as well as in patients with multidrug-resistant disease. Entecavir has also been shown to be effective in patients with HBV-associated clinical morbidity, including cirrhosis and liver failure, as well as in preventing recurrence of HBV following liver transplantation and in preventing reactivation of HBV after immunosuppres-sive therapy. Although the cost of anti-HBV therapy is a particular concern in the People's Republic of China, a number of studies have recently demonstrated that entecavir (particularly long-term therapy) represents a more cost-effective treatment strategy compared with other nucleos(t)ide therapies. Further research is required to assess the effects of entecavir combination therapy on hepatitis B surface antigen clearance, and in drug-resistant patients in the People's Republic of China.

Excellent liver transplantation survival and prevention of hepatitis B recurrence using hepatitis B immunoglobulin and nucleoside or nucleotide analogue along with treating physician adherence to treatment protocol

INTRODUCTION

The introduction of hepatitis B immunoglobulin (HBIG) in the early 1990s dramatically reduced recurrence of hepatitis B after orthotopic liver transplantation (OLT) and thus improved survival. Today a combination of HBIG and a nucleoside or nucleotide analogue (NUC) is recommended as prophylaxis. The optimal protocol is yet to be commonly agreed upon. The aim of this study was to review our results over 25 years.

PATIENTS AND METHODS

All 56 patients (45 males and 11 females) who underwent OLT due to hepatitis B infection between 1985-2009 were included in the review. Median age at transplantation was 51 years (range, 18-66). Seventeen patients (30%) had hepatocellular carcinoma (HCC) at transplantation.

RESULTS

The 1- and 5-year overall survival rates were 89% and 77%, respectively. The 23 patients who underwent transplantation before 2000 showed 1- and 5-year survival rates of 82% and 61%, respectively; the 33 who underwent transplantation between 2000 and 2009, the rates were 94% and 90%, respectively (P < .01). There was no difference in the 5-year survival rate between patients who had or did not have been HCC (75% vs 78%, respectively). Recurrence of hepatitis B, defined as seroconversion to HBsAg positivity, was observed in 9 patients. Three transplantation cases before 1992 consequently did not receive HBIG. The remaining 6, who all underwent OLT between 1993 and 2001, were administered HBIG. In all 6 cases periods of low anti-HBs titers were registered prior to recurrence; treating physician noncompliance with the protocol may have contributed to the low anti-HBs titers. No recurrence was registered after 2001.

CONCLUSION

With a combination of HBIG and NUC, excellent OLT results can be achieved for hepatitis B. It is, however, still important to maintain sufficient anti-HBs titers to prevent recurrence.

Evaluation and management of hepatitis B virus infection in hematopoietic stem cell transplantation: before and after transplantation

HBV infection remains a major global health problem and continues to be a common cause of liver-related morbidity and mortality in both immunocompetent and immunosuppressed individuals. Reactivation of HBV is a serious complication of chemotherapy/immunosuppressive therapy in patients with HBV infection. In this article, we aim to describe the diagnosis, prevention and management of HBV infection in allogeneic hematopoietic stem cell transplant candidates, from the pre- to post-transplant period. The data currently available suggest that all individuals with hemato-/onco-logical malignancies who undergo chemotherapy/immunosuppressive therapy should be screened for hepatotropic viruses such as HBV and HCV. HBV surface antigen-positive individuals who receive chemotherapy/immunosuppressive therapy are at considerable risk of HBV reactivation. Antiviral prophylaxis prevents HBV reactivation, decreases reactivation-related morbidity and mortality, and prevents interruptions in chemotherapy/immunosuppressive therapy in such individuals. The optimal duration of antiviral prophylaxis remains to be elucidated. The vaccination of HBV-naive recipients and their donors against HBV infection prior to transplantation plays an important role in preventing acquired HBV infection. The presence of hepatitis B surface antigen positivity is not an absolute contraindication for allogeneic hematopoietic stem cell transplantation.

Current role of Lamivudine regarding therapeutic response and resistance in children with chronic hepatitis B

PURPOSE

To identify the predictive factors of long-term therapeutic response or resistance to lamivudine treatment in children and adolescents with chronic hepatitis B.

METHODS

Eighty one children and adolescents with chronic hepatitis B were included, who received lamivudine treatment for at least 6 months. Their condition was monitored for at least 12 months (12-88 months) thereafter. Twenty one (25.9%) were preschool children (age≤6). For patients who had developed HBeAg seroconversion or breakthrough, univariate and multivariate analyses were used to identify the effects of age, gender, pretreatment alanine aminotransferase (ALT) and hepatitis B virus DNA levels.

RESULTS

HBeAg seroconversion occurred in 49 (60.5%) of the 81 patients after the initiation of the lamivudine therapy. In 65 patients whom were monitored for over 24 months, the seroconversion rate was significantly higher in younger patients (p=0.040), especially in those patients of preschool age (age≤6, p=0.031). The seroconversion rate was significantly higher in higher pretreatment ALT (p=0.003). The breakthrough occurred in 21 (25.9%) of the 81. The breakthrough rate was lower in younger aged patients (age≤6), and with higher pretreatment ALT levels, but no significant difference.

CONCLUSION

Younger age is a good predictor of HBeAg seroconversion in children with long-term lamivudine treatment as well as high pretreatment ALT levels.

Prophylactic Lamivudine to Improve the Outcome of Breast Cancer Patients With HBsAg Positive During Chemotherapy: A Meta-Analysis

CONTEXT

Raising the chemotherapy-induced HBV reactivation is parallel to the increment of chemotherapy treatments in breast cancer patients. This meta-analysis aims to evaluate the efficacy of prophylactic use of lamivudine in breast cancer patients with HBsAg positive during chemotherapy.

EVIDENCE ACQUISITION

MEDLINE, Pubmed, Ovid and Embase were used to search for clinical studies comparing with or without prophylactic use of lamivudine for HBV reactivation in breast cancer patients receiving chemotherapy. Outcomes of interest were the rate of HBV reactivation, incidence of hepatitis and incidence of hepatitis attributable to HBV reactivation, severity of hepatitis and severity of hepatitis attributable to HBV reactivation, the rate of chemotherapy disruption, and the rate of chemotherapy disruption attributable to HBV reactivation, overall mortality, and mortality attributable to HBV reactivation.

RESULTS

Four studies with 285 patients were included in this meta-analysis. The rate of HBV reactivation, incidence of hepatitis and incidence of hepatitis related to HBV reactivation were reduced by use of prophylactic lamivudine compared to control group. Pooled Odds Ratios (ORs) were 0.09 (95% confidence intervals [CI] 0.03-0.26; P < 0.0001), 0.23 (95% CI 0.06-0.92; P = 0.04), and 0.10 (95% CI 0.03-0.32; P < 0.0001) respectively. There was a reduction in chemotherapy disruption related to HBV reactivation by use of prophylactic lamivudine (pooled OR = 0.11; 95% CI 0.02-0.58; P = 0.01). Chemotherapy disruption, overall mortality, and mortality attributable to HBV reactivation were not significantly different between two groups. Pooled ORs were 0.42 (95% CI 0.11-1.58; P = 0.20), 0.37 (95% CI 0.07-2.04; P = 0.25), and 0.25 (95% CI 0.01-6.82; P = 0.41) respectively. Lamivudine was well-tolerated, and no additional toxicity was observed.

CONCLUSIONS

Use of prophylactic lamivudine may have positive effect on the outcome of breast cancer patients with HBsAg positive during chemotherapy.

The efficacy of lamivudine prophylaxis against hepatitis B reactivation in breast cancer patients undergoing chemotherapy: a meta-analysis

BACKGROUND/PURPOSE

Lamivudine has been recommended as prophylaxis for the reactivation of hepatitis B virus (HBV) infection in patients undergoing chemotherapy. However, information on breast cancer patients in particular has been lacking. The purpose of this meta-analysis was to assess the overall efficacy of lamivudine prophylaxis compared to untreated patients with hepatitis B S-antigen (HBsAg) seropositive breast cancer who had undergone chemotherapy.

METHODS

Studies that compared the efficacy of treatment with lamivudine prophylaxis versus no prophylaxis in HBsAg seropositive breast cancer patients were identified through Medline, Cochrane, and Embase databases.

RESULTS

Six studies involving 499 patients were analyzed. The rates of HBV reactivation in patients with lamivudine prophylaxis were significantly lower than those with no prophylaxis (risk ratio [RR] = 0.23, 95% confidence interval [CI]: 0.13-0.39, p < 0.00001). Patients given lamivudine prophylaxis had significant reductions in the rates of hepatitis attributable to HBV compared with those not given treatment (RR = 0.20, 95% CI: 0.08-0.47, p = 0.002). The rates of moderate and severe hepatitis in patients with lamivudine prophylaxis were significantly lower compared with those patients who had not received prophylaxis (RR = 0.25, 95% CI: 0.10-0.62, p < 0.003; RR = 0.25, 95% CI: 0.10-0.59, p = 0.002). Patients given lamivudine prophylaxis had significantly fewer disruptions of chemotherapy (RR = 0.36, 95% CI: 0.21-0.64, p = 0.0004). There was no significant heterogeneity in the comparisons.

CONCLUSION

Lamivudine prophylaxis in HBsAg seropositive breast cancer patients undergoing chemotherapy is effective in reducing HBV reactivation and HBV-associated morbidity and mortality.

Antiviral therapy against chronic hepatitis B in Brazil: high rates of lamivudine resistance mutations and correlation with HBV genotypes

The effectiveness of antiviral treatments of chronic hepatitis B has been poorly studied in Brazil. Here, hepatitis B virus (HBV) DNA positivity, drug resistance mutations and their association with HBV genotypes were evaluated in chronically HBV-infected patients under different drug regimens in Brazil. The study involved 129 patients under interferon or nucleos(t)ide analogue therapy for a median treatment time of 12 months. One hundred and five (81%) of these patients were treated with lamivudine (LAM), either in monotherapy or in combination with newer drugs, such as entecavir (ETV) or tenofovir (TDF). High (37.5-100%) rates of HBV DNA positivity were observed with all but one drug regimen (LAM + ETV). However, patients that were treated with ETV alone, TDF alone or with LAM combination therapies had a mean viral load that was 3-4 log lower than patients treated with LAM monotherapy. Of the patients treated with LAM, 47% developed resistance mutations. HBV genotypes A (59.1%), D (30.3%) and F (9.1%) were found. There was no association between the presence of LAM resistance mutations and genotypes, HBeAg status or treatment duration. Nevertheless, the rtM204V mutation was observed more frequently (12/13, 92%) in genotype A than in the others (p = 0.023). Six out of nine isolates that contained the rtM204I mutation belonged to genotype D and half of them displayed a single mutation. Genotype D isolates with the rtM204V variant preferentially displayed a triple mutation, while genotype A preferentially displayed a double mutation (p = 0.04).

Experience of anti-viral therapy in hepatitis B-associated membranous nephropathy, including Lamivudine-resistant strains

BACKGROUND/AIMS

Chronic hepatitis B infection is a common cause of secondary membranous nephropathy (MN) in endemic areas. Lamivudine treatment improves renal outcome in patients with hepatitis B virus-associated MN (HBV-MN), but prolonged use leads to the emergence of lamivudine-resistant variants. We describe our experience treating lamivudine-resistant and other strains of HBV-MN with new antiviral drugs.

METHODS

Of the 89 patients biopsied and diagnosed with MN from 1996 to 2011, 10 positive for hepatitis B surface antigen were recruited for this study. We investigated the clinical courses, therapeutic responses, and prognoses of patients with HBV-MN.

RESULTS

The incidence of HBV-MN among the original 89 patients was 11.2%. Of these patients, four were treated with supportive care and six with antiviral drugs. One of the four patients treated with supportive care had a spontaneous remission. Four of the six patients treated with antiviral drugs were given lamivudine, and the other two were given entecavir. Two of the four patients treated with lamivudine achieved complete remission with seroconversion (i.e., development of anti-hepatitis B e antigen antibodies), whereas the other two had lamivudine-resistant strains, which were detected at 22 and 23 months after lamivudine treatment, respectively. We added adefovir to the treatment regimen for one of these patients, and for the other patient we substituted clevudine for lamivudine. Both of these patients experienced complete remission, as did the two patients initially treated with entecavir, neither of whom showed resistance to the drug.

CONCLUSIONS

New nucleoside analogues, such as entecavir, adefovir, and clevudine, can be effective for treatment of HBV-MN, including lamivudine-resistant strains.

Successful establishment and evaluation of a new animal model for studying the hepatitis B virus YVDD mutant

The treatment of infection with lamivudine-resistant mutants of hepatitis B virus (HBV) with mutations in the YMDD motif has become a crucial issue in the clinic. In this work, the plasmids pcDNA3.1 (+)-HBV/C-YVDD and pcDNA3.1 (+)-HBV/C-YMDD were constructed and injected into BALB/c mice using a hydrodynamics-based procedure to investigate viral replication and expression of HBV lamivudine-resistant YVDD mutants in vivo. Compared with the YMDD group, HBsAg levels were higher in sera of mice in the YVDD group, but HBeAg levels were lower on day 1 after injection. Levels of HBcAg in hepatocytes were higher in the YVDD group on day 1, whereas the HBsAg levels were lower. The levels of HBV mRNA in the liver were higher in mice in the YVDD group on day 1 after injection. The results showed that injection with these plasmids resulted in efficient initiation of replication of HBV in mice and also suggested that the combined mutations in YVDD mutants could affect the replication process.

Viral quasispecies evolution

Evolution of RNA viruses occurs through disequilibria of collections of closely related mutant spectra or mutant clouds termed viral quasispecies. Here we review the origin of the quasispecies concept and some biological implications of quasispecies dynamics. Two main aspects are addressed: (i) mutant clouds as reservoirs of phenotypic variants for virus adaptability and (ii) the internal interactions that are established within mutant spectra that render a virus ensemble the unit of selection. The understanding of viruses as quasispecies has led to new antiviral designs, such as lethal mutagenesis, whose aim is to drive viruses toward low fitness values with limited chances of fitness recovery. The impact of quasispecies for three salient human pathogens, human immunodeficiency virus and the hepatitis B and C viruses, is reviewed, with emphasis on antiviral treatment strategies. Finally, extensions of quasispecies to nonviral systems are briefly mentioned to emphasize the broad applicability of quasispecies theory.

Chronic hepatitis B infection

The management of chronic hepatitis B virus (HBV) infection requires understanding the natural history of the disease as well as the risks, benefits, and limitations of the therapeutic options. This article covers the principles governing when to start antiviral therapy, discusses recent advances using hepatitis B surface antigen quantification to better define various phases of infection, describes the use of HBV core, precore, and viral genotyping as well as host IL28B genotyping to predict response to interferon therapy, and reports on the management of HBV in 3 special populations (pregnancy, postliver transplantation, and in the setting of chemotherapy or immunosuppression).

Randomised clinical trial: the benefit of combination therapy with adefovir and lamivudine for chronic hepatitis B

BACKGROUND

Combination antiviral therapy holds the promise of increasing response rates while decreasing antiviral resistance, but has yet to be shown to be beneficial or necessary in chronic hepatitis B.

AIM

To evaluate the benefit of combination therapy with adefovir and lamivudine versus adefovir alone in maintaining virological, biochemical and histological responses.

METHODS

Patients with chronic hepatitis B with and without previous lamivudine therapy were randomised to receive adefovir alone (10 mg/daily) or adefovir and lamivudine (100 mg/daily) for up to 192 weeks. Study endpoints were (i) maintained virological (HBV DNA <500 copies/mL), biochemical and histological response, (ii) loss of HBeAg and (iii) loss of HBsAg.

RESULTS

A total of 41 patients were enrolled, including 31 HBeAg -positive and 31 treatment-naïve subjects. 30 patients remained on assigned therapy at 192 weeks. The percentage of patients achieving a combined maintained response was higher in the combination than the monotherapy arm, both at week 48 (59% vs. 26%, P = 0.06) and 192 (68% vs. 31%, P = 0.03). At week 192, 76% of the combination vs. 36% of the monotherapy group had loss of HBeAg (P = 0.03). One patient receiving adefovir cleared HBsAg. Adefovir resistance developed in 6 of 19 (32%) monotherapy but none of 22 combination treated patients (P = 0.03).

CONCLUSIONS

Extended combination therapy with lamivudine and adefovir is associated with a high rate of long-term virological and biochemical response. Adefovir monotherapy appears to be less effective mainly because of poor initial response and the ultimate development of antiviral resistance (www.Clinical. Trials.gov NCT00023309).

Characterization of resistance to the nonnucleoside NS5B inhibitor filibuvir in hepatitis C virus-infected patients

Filibuvir (PF-00868554) is an investigational nonnucleoside inhibitor of the hepatitis C virus (HCV) nonstructural 5B (NS5B) RNA-dependent RNA polymerase currently in development for treating chronic HCV infection. The aim of this study was to characterize the selection of filibuvir-resistant variants in HCV-infected individuals receiving filibuvir as short (3- to 10-day) monotherapy. We identified amino acid M423 as the primary site of mutation arising upon filibuvir dosing. Through bulk cloning of clinical NS5B sequences into a transient-replicon system, and supported by site-directed mutagenesis of the Con1 replicon, we confirmed that mutations M423I/T/V mediate phenotypic resistance. Selection in patients of an NS5B mutation at M423 was associated with a reduced replicative capacity in vitro relative to the pretherapy sequence; consistent with this, reversion to wild-type M423 was observed in the majority of patients following therapy cessation. Mutations at NS5B residues R422 and M426 were detected in a small number of patients at baseline or the end of therapy and also mediate reductions in filibuvir susceptibility, suggesting these are rare but clinically relevant alternative resistance pathways. Amino acid variants at position M423 in HCV NS5B polymerase are the preferred pathway for selection of viral resistance to filibuvir in vivo.

Treatment of chronic hepatitis B with nucleos(t)ide analogues

Recently antiviral therapies for chronic hepatitis B using nucleos(t)ide analogues have become standard treatment modalities on the basis of several independent guidelines, starting with those of the American Association for the Study of Liver Diseases (AASLD) and other such organizations and bodies, including the European Association for the Study of the Liver (EASL), the Asian Pacific Association for the Study of the Liver (APASL), and the Japanese Ministry of Health, Labour and Welfare (MHLW)'s research team. The philosophies underlying such treatment strategies are considered basically equivalent. MHLW's guidelines define subjects for medical intervention to be cases measuring alanine aminotransferase (ALT) ≥31 IU/L, with serological hepatitis B virus (HBV) DNA level ≥5 log copies/mL for hepatitis B e antigen (HBeAg)-positive cases, and serological HBV DNA level ≥4 log copies/mL for HBeAg-negative cases. These Japanese guidelines advocate entecavir as the first-line treatment option for nucleos(t)ide-naïve patients, and combination treatment of lamivudine and adefovir as the basis of treatment for patients with lamivudine- and/or entecavir-resistant viruses. Of particular note for patients undergoing lamivudine treatment with persistent HBV DNA level < 2.1 log copies/mL is the recommendation of a switch to entecavir. Early detection of drug-resistant virus is desirable after initiation of nucleos(t)ide analogue treatment, but such a procedure is not uniformly available at all medical institutions. Nevertheless, timely estimation of potential early-stage drug-resistant virus development is crucial for getting a head start on treatment. HBV core-related antigen (HBcrAg) level or HBV DNA level are considered useful markers for the appearance of such drug-resistant viruses.

Comparison of entecavir and lamivudine in preventing hepatitis B reactivation in lymphoma patients during chemotherapy

During chemotherapy for lymphoma, the administration of cytotoxic agents and rituximab often results in hepatitis B reactivation (incidence, 14-72%). This study was designed to compare the efficacy of entecavir and lamivudine in preventing hepatitis B reactivation in lymphoma patients. Between January 2007 and February 2009, patients treated in four hospitals in China were screened to identify those most appropriate for analysis. These patients received either entecavir or lamivudine during chemotherapy and for 6 months after completion of chemotherapy. A total of 34 patients received entecavir and 89 patients received lamivudine. Compared with the lamivudine group, the entecavir group had significantly lower rates of hepatitis (5.9 vs 27.0%, P = 0.007), hepatitis B reactivation (0 vs 12.4%, P = 0.024) and disruption of chemotherapy (5.9 vs 20.2%, P = 0.042). All patients with hepatitis B reactivation had B-cell non-Hodgkin's lymphoma (stage III-IV). In lymphoma patients under chemotherapy treatment, entecavir is more effective than lamivudine in preventing hepatitis B reactivation. For patients with advanced stage disease, entecavir should be considered the primary preventive therapy.

HBV DNA level at 24 weeks is the best predictor of virological response to adefovir add-on therapy in patients with lamivudine resistance

BACKGROUND

The aim of this study was to investigate the relationship between HBV DNA levels at baseline and on-treatment and the virological response at 96 weeks after adefovir add-on therapy in chronic hepatitis B (CHB) patients with lamivudine resistance.

METHODS

Lamivudine and adefovir combination therapy was administered to 122 CHB patients for >24 months.

RESULTS

Virological response (HBV DNA negativity) was achieved in 53 (43.3%) and 62 patients (50.8%) at 48 and 96 weeks, respectively. The receiver operating characteristic curve analysis showed that the HBV DNA level at week 24 had a greater power (area under the receiver operating characteristic curve 0.978; 95% CI 0.949, 1.000; P<0.001) to predict the virological response at week 96 of treatment than did the pre-treatment HBV DNA level (area under the receiver operating characteristic curve 0.771; 95% CI 0.640, 0.902; P<0.001). The best cutoff value for the HBV DNA level, at week 24, for the prediction of the virological response at week 96 was 200 IU/ml (3 log(10) copies/ml), with a sensitivity and specificity of 90.3% and 95.0%, respectively. Using this time frame and cutoff value, 56 (90.3%) out of 62 patients that had a virological response at 96 weeks had <200 IU/ml HBV DNA at 24 weeks.

CONCLUSIONS

Although the HBV DNA level at baseline is often used to predict the antiviral potency of lamivudine and adefovir combination treatment in CHB patients with lamivudine resistance, the results of this study suggest that the HBV DNA level at 24 weeks is a better marker for the virological response.

High rate of complete viral suppression with combination therapy in patients with chronic hepatitis B and prior treatment failure

BACKGROUND

Combination therapy for chronic hepatitis B virus (HBV) infection is recommended for patients with antiviral resistance (AVR) or partial response (PR) to earlier antiviral therapy; however, data on outcomes are limited.

GOALS

To determine the rate of complete viral suppression (CVS) with combination therapy and to compare CVS among different indications and treatment regimens.

METHODS

A cohort of 109 consecutive patients with chronic hepatitis B from 3 liver clinics in Northern California was retrospectively studied. All patients started combination therapy between April 2004 and August 2009 for the following indications: AVR (n = 29), PR (n = 60), or others (n = 20). Combination treatments included lamivudine (LAM), adefovir (ADV), telbivudine (LdT), entecavir (ETV), tenofovir (TDF), and emtricitabine (FTC). CVS was defined as undetectable serum HBV DNA <100 IU/mL.

RESULTS

Among the patients, who were nearly all Asian (99%), 73% had ≥ 2 prior treatments and 82% had treatment failure (AVR or PR). Median treatment duration of combination therapy was 21 months (range, 6 to 50 mo). The majority (77%) achieved CVS after 6 months of various combination regimens: 80% for ETV+TDF, 76% for TDF+LAM or FTC or LdT, 75% for ETV+ADV, and 69% for ADV+LAM or LdT (P = 0.86). After 6 months of therapy, CVS was observed in a similar proportion of patients treated for PR and AVR (72% and 74%, respectively).

CONCLUSIONS

Although the majority of 109 treatment-experienced patients had prior treatment failure, high rates of CVS were rapidly achieved and did not significantly differ between indications of AVR and PR or between ETV-based and TDF-based regimens.

Inhibitory effect of locked nucleic acid antisense oligonucleotides versus lamivudine on HBV replication in HepG2.2.15 cells

AIM: To compare the inhibitory effect of locked nucleic acid antisense oligonucleotides (antisense-LNA) and lamivudine on HBV replication in HepG2.2.15 cells.

METHODS: Antisense-LNA was introduced into HepG2.2.15 cells by cationic liposome-mediated transfection. Supernatants were collected 2, 4, 6, 8, 10 days after medication. The concentrations of HBsAg and HBeAg in cell supernatants were tested by ELISA. HBV DNA levels in cell supernatants were determined by FQ-PCR. Cell toxicity of antisense-LNA and lamivudine was detected by MTT assay.

RESULTS: Lamivudine only inhibited viral DNA synthesis. Antisense-LNA effectively inhibited the expression of HBsAg and HBeAg and the replication of HBV DNA (67.69%, 59.71%, 62.96%, P < 0.05) in a time-dependent manner. Both antisense-LNA and lamivudine showed no obvious cell toxicity.

CONCLUSION: The anti-HBV effect of antisense-LNA is more effective than that of lamivudine in HepG2.2.15 cells.

HBV lamivudine resistance among hepatitis B and HIV coinfected patients starting lamivudine, stavudine and nevirapine in Kenya

Widespread use of lamivudine in antiretroviral therapy may lead to hepatitis B virus resistance in HIV-HBV coinfected patients from endemic settings where tenofovir is not readily available. We evaluated 389 Kenyan HIV-infected adults before and for 18 months after starting highly active antiretroviral therapy with stavudine, lamivudine and nevirapine. Twenty-seven (6.9%) were HBsAg positive and anti-HBs negative, 24 were HBeAg negative, and 18 had HBV DNA levels ≤ 10,000 IU/mL. Sustained HBV suppression to <100 IU/mL occurred in 89% of 19 evaluable patients. Resistance occurred in only two subjects, both with high baseline HBV DNA levels. Lamivudine resistance can emerge in the setting of incomplete HBV suppression but was infrequently observed among HIV-HBV coinfected patients with low baseline HBV DNA levels.

Current status of antiviral therapy for hepatitis B

Chronic hepatitis B (CHB) is a major public health problem affecting up to 400 million people globally. Complications of CHB including liver failure and hepatocellular carcinoma result in 1.2 million deaths per year, making CHB the 10th leading cause of mortality worldwide. The natural history of CHB is variable and complex. The past decade witnessed important developments for the therapy of hepatitis B and marked the new era of oral therapy. The ultimate goal of CHB therapy is to arrest the progression of liver injury and to prevent the development of liver failure and hepatocellular carcinoma. Currently, six agents are approved for the treatment of CHB. Each of these agents, given as monotherapy, has been shown to produce virological, biochemical, and histological benefits for both HBeAg positive and negative CHB. There are, however, limitations in spite of their efficacy. The significant side-effect profile of interferon, for example, limits its long-term use. The approved oral agents are tolerable with prolonged use but drug resistance could limit long-term monotherapy. To date, combination therapy with nucleoside analogue and pegylated interferon or two nucleos(t)ide analogues given for one year does not show superiority in durability of response compared to monotherapy. Ongoing research effort is critical to identify the ideal hepatitis B therapy that is safe, effective, and produces durable response with a finite course of therapy. It is equally important to conduct a well designed, prospective natural history study to identify predictors of disease progression. This will accurately guide treatment strategy for this important disease.