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Background: About 20% of on-treatment patients with chronic hepatitis B (CHB) experienced low-level viraemia (LLV), which is associated with persistent low-grade inflammation, fibrosis progression, and increased risk of hepatocellular carcinoma. We aimed to investigate the high-risk factors related to LLV., Methods: In this retrospective study, patients receiving entecavir (ETV) treatment from January 2018 to January 2023 were enrolled, and were divided into a LLV (HBV DNA 20-2000 IU/mL) cohort and a complete virological response (CVR) (HBV DNA < 20 IU/mL) cohort according to the virological response at week 48 posttreatment. Treatment baseline characteristics were retrieved from electronic medical records. Multivariate logistic regression was performed., Results: Totally, 1653 patients were enrolled, male patients accounted for 73.0%; the median age was 44 years; the mean HBV DNA level was 5.9 Log 10 IU/ml. Among them, 472 (28.6%) experienced LLV. Multivariate analysis showed that HBeAg positivity (OR = 2.650, 95% CI: 2.000-3.511, p < 0.001), HBV DNA ≥ 6.0 Log 10 IU/mL (OR = 1.370, 95% CI: 1.054-1.780, p = 0.019), qHBsAg ≥ 9000 IU/mL (OR = 4.472, 95% CI: 3.410-5.866, p < 0.001), cirrhosis (OR = 1.650, 95% CI: 1.234-2.207, P = 0.001), LSM ≥ 13.0 kPa (OR = 1.644, 95% CI: 1.203-2.246, p = 0.002), and PLT < 100×10 9 /L (OR = 1.450, 95% CI: 1.094-1.922, p = 0.010) at baseline were related to the development of LLV., Conclusions: High HBV DNA/HBsAg quantification/LSM, low PLT, HBeAg positivity, and liver cirrhosis were high-risk factors associated with LLV in patients receiving entecavir treatment., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Li, Chen, Jia, He, Cui, Du, Kang, Feng, He, Jin, Chen, Wang, Ji, Lau and Wu.)

Background & Aim: Hepatitis B reactivation related to the use of immunosuppressive therapy remains a major cause of liver-related morbidity and mortality in hepatitis B endemic Asia-Pacific region. This clinical practice guidelines aim to assist clinicians in all disciplines involved in the use of immunosuppressive therapy to effectively prevent and manage hepatitis B reactivation., Methods: All publications related to hepatitis B reactivation with the use of immunosuppressive therapy since 1975 were reviewed. Advice from key opinion leaders in member countries/administrative regions of Asian-Pacific Association for the study of the liver was collected and synchronized. Immunosuppressive therapy was risk-stratified according to its reported rate of hepatitis B reactivation., Recommendations: We recommend the necessity to screen all patients for hepatitis B prior to the initiation of immunosuppressive therapy and to administer pre-emptive nucleos(t)ide analogues to those patients with a substantial risk of hepatitis and acute-on-chronic liver failure due to hepatitis B reactivation., (© 2021. Asian Pacific Association for the Study of the Liver.)

Background and Aim: Cytokine storm has been reported in patients with coronavirus disease 2019 (COVID-19) due to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. We examine the incidence of acute on chronic liver failure (ACLF) in COVID-19 patients with pre-existing compensated chronic liver disease (CLD)., Methods: From 20 Jan 2020 to 7 Feb 2020, we studied 140 consecutive COVID-19 patients admitted to either Fuyang Second People's Hospital (FYSPH), Anhui or the Fifth Medical Center of Chinese PLA General Hospital (PLAGH) in Beijing, China. Pre-existing CLD includes those with liver cirrhosis assessed by APRI/FIB-4 score and /or ultrasound; NAFLD as identified by either ultrasound or hepatic steatosis index with significant liver fibrosis and chronic hepatitis B (CHB) or hepatitis C (CHC) infection. The diagnosis, grading of severity and clinical management of COVID-19 patients complied to the guideline and clinical protocol issued by the China National Health Commission. All patients had liver function test at least twice weekly till discharge with full recovery or death., Results: In total, 3 had liver cirrhosis, 6 patients had CHB, 13 had NAFLD with significant liver fibrosis (one also had CHB). On admission, none had liver decompensation. COVID-19 disease progression was significantly less frequent in non-CLD patients (10/118 8.5%) than CLD patients (13/22 59.1%, p < 0.001). One patient with CLD had acute-on-chronic liver failure (ACLF)., Conclusion: Disease progression is significantly higher in those COVID-19 patients with CLD as compared to those with no CLD. ACLF can also occur in patient with pre-existing compensated CLD who had severe COVID-19.

Since the registration of the first effective nucleoside analogue against the hepatitis B virus almost two decades ago, major progress has been made in the management of chronic hepatitis B infection. However, hepatitis B-related morbidity and mortality remain a major global health threat. This is partly due to the escalating costs and the decrease in compliance related to the need for prolonged therapy for most patients who cannot be "cured". New biomarkers such as quantitative hepatitis B surface antigen might help to determine if hepatitis B e antigen negative patients can be taken off nucleos(t)ide analogues. On the other hand, novel compounds that target the viral life cycle or modulate host immune response are in the pipeline. In the next few years, one should expect breakthrough advancement to be made leading to a "cure" for patients with chronic hepatitis B infection by inducing hepatitis surface antigen loss with or without the development of the hepatitis B surface antibody. In addition, attention and necessary actions should also be taken in patients with hepatitis B infection who are being treated with immunosuppressive therapy and direct anti-viral (DAAs) agents for hepatitis C infection to prevent hepatitis from hepatitis B reactivation., (© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Worldwide, some 240 million people have chronic hepatitis B virus (HBV), with the highest rates of infection in Africa and Asia. Our understanding of the natural history of HBV infection and the potential for therapy of the resultant disease is continuously improving. New data have become available since the previous APASL guidelines for management of HBV infection were published in 2012. The objective of this manuscript is to update the recommendations for the optimal management of chronic HBV infection. The 2015 guidelines were developed by a panel of Asian experts chosen by the APASL. The clinical practice guidelines are based on evidence from existing publications or, if evidence was unavailable, on the experts' personal experience and opinion after deliberations. Manuscripts and abstracts of important meetings published through January 2015 have been evaluated. This guideline covers the full spectrum of care of patients infected with hepatitis B, including new terminology, natural history, screening, vaccination, counseling, diagnosis, assessment of the stage of liver disease, the indications, timing, choice and duration of single or combination of antiviral drugs, screening for HCC, management in special situations like childhood, pregnancy, coinfections, renal impairment and pre- and post-liver transplant, and policy guidelines. However, areas of uncertainty still exist, and clinicians, patients, and public health authorities must therefore continue to make choices on the basis of the evolving evidence. The final clinical practice guidelines and recommendations are presented here, along with the relevant background information.

Background & Aims: Noninvasive techniques are needed to assess hepatic fibrosis in patients with chronic hepatitis B. We developed a scoring system to determine the degree of fibrosis in patients with genotype B or genotype C hepatitis B virus (HBV) infection and positive for the hepatitis B e antigen., Methods: We performed a retrospective study to identify baseline variables associated with the severity of fibrosis (METAVIR scores, F0-F4) in a large phase 3 clinical trial of predominantly Asian patients (n = 710), using multivariate logistic regression analyses. Significant variables were used to construct predictive models using optimal cut-off values. The final model was validated in similar patients from a large phase 4 clinical trial (n = 465)., Results: We developed 2 prediction scoring systems (PSs). PS1 analyzed data on HBV genotype (B vs. C), patient age (<30 vs. ≥30 y), level of hepatitis B surface antigen (≤17,500 vs. >17,500 IU/mL), and level of alanine aminotransferase (≤3-fold vs. >3-fold the upper limit of normal). PS2 analyzed data on only age and level of hepatitis B surface antigen. PS1 identified patients with F0 to F1 vs. F2 to F4 fibrosis with more than 87% specificity and a positive predictive value greater than 75; it identified patients with F0 to F2 vs. F2 to F4 fibrosis with approximately 95% specificity and a positive predictive value (PPV) of approximately 97%. PS2 identified patients with F0 to F1 fibrosis with less accuracy than PS1, but identified patients with F0 to F2 fibrosis with an almost identical level of sensitivity and PPV., Conclusions: We developed a simple scoring system to determine the severity of fibrosis in patients with genotypes B or C HBV infection who are hepatitis B e antigen positive. Our system differentiated patients with no or mild fibrosis (F0-F1) from those with marked or severe (F2-F4) fibrosis with a high PPV. The high level of specificity for the identification of nonsevere fibrosis (F0-F2) limits the risk of overlooking patients with severe fibrosis (F3-F4)., (Copyright © 2015 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Background & Aims: This study investigated the antiviral efficacy and safety of telbivudine in combination with pegylated interferon (PegIFN) alpha-2a in chronic hepatitis B (CHB) patients., Methods: This was a randomized, open-label, multicentre study, in treatment-naïve patients with HBeAg-positive CHB, comparing the efficacy and safety of telbivudine in combination with PegIFN alpha-2a with telbivudine monotherapy and PegIFN alpha-2a monotherapy. The study was terminated early due to increased rates of peripheral neuropathy in the combination-therapy group., Results: Of the 159 patients randomized (from 300 planned) 50 were assigned to combination therapy, 55 to telbivudine, 54 to PegIFN, and 110 (18, 49, and 43, respectively) reached week 24. Peripheral neuropathy occurred in 7/50, 1/54, and 0/54 patients in the three groups of safety populations, respectively. No relationship between the occurrence of peripheral neuropathy and other variables (e.g., pharmacokinetic data, treatment efficacy, ALT levels, creatine kinase elevations) were observed. At week 24, undetectable HBV DNA (<300 copies/ml) was achieved by 71% (12/17), 35% (17/48), and 7% (3/42) of patients, with available data receiving combination therapy, telbivudine monotherapy and PegIFN monotherapy, respectively (p = 0.022 for combination therapy vs. telbivudine; p<0.0001 for combination therapy vs. PegIFN)., Conclusions: Combination therapy carried an increased risk of peripheral neuropathy. Despite the rapid and profound reductions in HBV DNA levels, combination therapy with telbivudine and PegIFN should not be used., (Copyright © 2014. Published by Elsevier B.V.)

Background & Aims: Little is known about the benefit of antiviral therapy for hepatitis B e antigen (HBeAg)-positive patients with high viral load and normal levels of alanine aminotransferase. We evaluated the effects of single and combination therapies in immune-tolerant patients with chronic hepatitis B., Methods: In a double-blind study, nucleos(t)ide-naïve patients with high levels of hepatitis B virus (HBV) DNA who were positive for HBeAg and had normal levels of alanine aminotransferase were randomly assigned to groups given either oral tenofovir disoproxil fumarate (TDF, 300 mg) and placebo (n = 64) or a combination of TDF (300 mg) and emtricitabine (200 mg, n = 62) for 192 weeks. The primary end point was proportion of patients with serum levels of HBV DNA <69 IU/mL at week 192., Results: The study population (mean age was 33 years; 89% were Asian) was predominantly infected with HBV genotypes B and C (93%), 99% were HBeAg positive with a mean baseline level of HBV DNA of 8.41 log10 IU/mL. At week 192, 55% of patients (35 of 64) in the TDF+placebo group and 76% of patients (47 of 62) in the TDF+emtricitabine group had levels of HBV DNA <69 IU/mL (P = .016). No patients were found to have viral resistance to therapy. HBeAg seroconversion occurred in 3 patients (5%), all in the TDF+placebo group; no patient had loss of hepatitis B surface antigen. In multivariate analysis, female sex (odds ratio = 7.05; P = .002) and TDF+emtricitabine treatment (odds ratio = 3.9; P = .01) were associated with a favorable response. Both regimens were well tolerated., Conclusions: In HBeAg-positive patients with chronic HBV infection, high viral loads, normal levels of alanine aminotransferase, and therapy with the combination of TDF and emtricitabine provided better viral suppression than TDF alone, although rates of HBeAg seroconversion and hepatitis B surface antigen loss were low., (Copyright © 2014 AGA Institute. Published by Elsevier Inc. All rights reserved.)

HIV infection has a significant impact on the natural progression of hepatitis B virus (HBV) related liver disease. In HIV-HBV co-infected patients, little is known about mutations in the HBV genome, which can influence severity of liver disease. The aim of this study was to characterize and to determine the frequency of known clinically significant mutations in the HBV genomes from HIV-HBV co-infected patients and from HBV mono-infected patients. To accomplish this, genomic length HBV sequencing was performed in highly-active anti-retroviral therapy (HAART)-naïve HIV-HBV co-infected patients (n=74) and in anti-HBV therapy-naïve HBV mono-infected patients (n=55). The frequency of HBV mutations differed between the co-infected and mono-infected patients when comparing patients with the same genotype. BCP mutations A1762T and G1764A were significantly more frequent in HBV genotype C mono-infection and the -1G frameshift was significantly more frequent in co-infection and was only observed in HBV genotype A co-infection. PreS2 deletions were observed more frequently in the setting of co-infection. Further work is needed to determine if these mutational patterns influence the differences in liver disease progression in HIV-HBV co-infected and HBV mono-infected patients., (Copyright 2010 Elsevier Inc. All rights reserved.)

It remains uncertain whether hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) and pregenomic RNA (pgRNA) can be detected in the serum or peripheral blood mononuclear cells (PBMC) of patients with chronic hepatitis B (CHB) infection. We examined HBV cccDNA and pgRNA in the serum and PBMC, and investigated the effect of lamivudine therapy on the viral loads in the PBMC of CHB patients. Paired serum and PBMC samples from 50 treatment-naïve CHB patients [25 hepatitis B e antigen (HBeAg) positive and 25 HBeAg negative] were quantified for total HBV DNA, cccDNA and pgRNA by real time polymerase chain reaction. HBV cccDNA and pgRNA were below the lower detection limit in all serum samples, and in 84% of PBMC. HBV DNA (r = 0.889, P < 0.001) and pgRNA (r = 0.696, P < 0.001) in PBMC correlated with the HBV DNA in serum. In the longitudinal study, 30 patients treated with lamivudine therapy for a median duration of 34 weeks (range 12-48 weeks) were examined. The median HBV DNA reduction in PBMC before and after treatment was 1.318 (range -0.471 to 3.846) log units, which was significantly lower than serum HBV DNA reduction [3.371 (range -0.883 to 9.454) log units, P < 0.05]. HBV cccDNA and pgRNA were undetectable in the serum of CHB patients. HBV viral loads in PBMC correlated with serum HBV DNA. Lamivudine therapy had less effect on the HBV viral loads in PBMC compared with the serum viral loads.

Unlabelled: Defective hepatitis B virus DNA (dDNA) is reverse-transcribed from spliced hepatitis B virus (HBV) pregenomic messenger RNA (pgRNA) and has been identified in patients with chronic HBV (CH-B). The major 2.2-kb spliced pgRNA encodes a novel HBV gene product, the hepatitis B splice protein (HBSP) via a deletion and frame shift within the polymerase. Although spliced RNA and HBSP expression have been associated with increased HBV DNA levels and liver fibrosis, the role of dDNA in HBV-associated disease is largely undefined. Our aims were to (1) compare the relative proportions of dDNA (% dDNA) in a range of HBV-infected serum samples, including patients with human immunodeficiency virus (HIV)/HBV coinfection and HBV-monoinfected persons with differing severities of liver disease, and (2) determine the effect of mutations associated with drug resistance on defective DNA production. Defective DNA was detected in 90% of persons with CH-B. There was no significant difference in the relative abundance of dDNA between the monoinfected and HIV/HBV-coinfected groups. We also found no association between the % dDNA and alanine aminotransferase, hepatitis B e antigen status, HBV DNA levels, fibrosis levels, compensated or decompensated liver cirrhosis, genotype, or drug treatment. However, the % dDNA was significantly lower in individuals infected with lamivudine-resistant (LMV-R) HBV compared with wild-type HBV (P < 0.0001), indicating that antiviral drug resistance alters the balance between defective and genomic length DNA in circulation. Experiments in vitro using HBV encoding LMV-R mutations confirmed these results., Conclusion: Our results identified no association between dDNA and parameters associated with disease status and suggested that the relative abundance of dDNA is largely dependent on the integrity of the HBV polymerase and is unrelated to the severity of liver disease.

Background: Clevudine is a polymerase inhibitor that has the unusual feature of delayed viral rebound after therapy in some patients which may be related to its pharmacokinetics., Aim: To characterize pharmacokinetic and pharmacodynamic profile of clevudine, a potent hepatitis B polymerase inhibitor., Methods: A multicenter, randomized study comparing 10, 30 and 50 mg clevudine once daily for 12 weeks with 24 weeks off-treatment follow-up. Patients had chronic HBV infection, were nucleoside-naïve without co-infection. HBV viral load (VL) was assayed using Digene Hybrid Capture II with a lower limit of detection of 4700 copies/mL (940 IU/mL). Clevudine levels were measured using a liquid chromatography/mass spectrometery method., Results: A total of 31 patients were enrolled into the 10 mg (n = 10), 30 mg (n = 11) and 50 mg (n = 10) groups, respectively. At week 12, the median VL change was -3.2, -3.7 and -4.2 log(10) copies/mL (-0.64, -0.74 and -0.84 log(10) IU/mL) in the 10, 30 and 50 mg groups, respectively (P = 0.012). At week 12, one of 10, five of 11 and two of 10 patients had VL below the assay lower limit of detection. Clevudine was well tolerated with no severe/serious adverse events. The mean plasma half-life of clevudine was 70 h and consequently is not the cause of the delayed viral rebound seen in some patients. Through modelling, 97% of the maximal treatment effect was reached with a 30 mg daily dose. Six patients had genomic changes without viral rebound., Conclusion: Clevudine appears to be a potent and tolerable (over 12 weeks) anti-viral and the optimal dosage appears to be 30 mg once daily.

Objective: In a trial of patients with hepatitis B e antigen (HBeAg)-negative chronic hepatitis B, 24 week post-treatment biochemical and virological response rates with peginterferon alpha-2a with or without lamivudine were significantly higher than with lamivudine alone. The effect of pre-treatment factors on post-treatment responses was investigated., Methods: Multivariate analyses were performed using available data from 518 patients treated with peginterferon alpha-2a with or without lamivudine, or with lamivudine alone. A post-treatment response was defined as alanine aminotransferase (ALT) normalisation and hepatitis B virus (HBV) DNA level of <20,000 copies/ml., Results: In logistic regression analyses across all treatment arms, peginterferon alpha-2a (with or without lamivudine) therapy, younger age, female gender, high baseline ALT, low baseline HBV DNA and HBV genotype were identified as significant predictors of combined response at 24 weeks post-treatment. In the peginterferon alpha-2a and lamivudine monotherapy arms, patients with genotypes B or C had a higher chance of response than genotype D infected patients (p<0.001), the latter responding better to the combination than to peginterferon alpha-2a monotherapy (p = 0.015). At 1 year post-treatment, response rates by intention-to-treat analysis were 19.2% for the peginterferon alpha-2a, 19.0% for the combination, and 10.0% for the lamivudine groups, with genotypes B or C associated with a sustained combined response to peginterferon alpha-2a with or without lamivudine therapy., Conclusions: Baseline ALT and HBV DNA levels, patient age, gender, and infecting HBV genotype significantly influenced combined response at 24 weeks post-treatment, in patients treated with peginterferon alpha-2a and/or lamivudine. At 1 year post-treatment HBV genotype was significantly predictive of efficacy for patients treated with peginterferon alpha-2a with or without lamivudine.

Lamivudine monoprophylaxis against hepatitis B virus (HBV) reinfection after liver transplantation is associated with recurrence due to escape mutants and second generation recombinant HBV vaccine is not effective. We studied the efficacy of two courses each of three double-doses (20 microg) of third-generation recombinant pre-S containing vaccine (Sci-B-Vac) in 20 patients on lamivudine prophylaxis at a median of 637 days (range, 390-2666 days) after transplantation. At enrollment, all patients were seronegative for HBsAg, anti-HBs and HBVDNA (by qPCR). Lamivudine (100 mg/day) was continued throughout the study. Five patients (25%) responded to the first course and five additional patients responded after the second course (overall response rate 50%). The response rate was 88% in patients younger than 50 years old and 25% in older patients (p = 0.02). The median peak anti-HBs titer was 153 mIU/mL with six responders having a titer >100 mIU/mL and seven sustained >6 months. Among seven previous nonresponders to second generation recombinant vaccine, three (44%) responded. At the end of the study, all patients remained seronegative for HBsAg. In conclusion, Sci-B-Vac is effective in about 50% of patients receiving lamividine prophylaxis and may prevent recurrence due to escape mutants.

Background/aim: Although 48-week therapy with pegylated-interferons has been shown to be effective for the treatment of chronic hepatitis B virus infection, the efficacy of a shorter duration of therapy with pegylated interferons is unknown., Method: We reviewed 53 hepatitis B e antigen positive Chinese patients treated with 48 weeks of pegylated interferon alpha-2a or 24 weeks of pegylated interferon alpha-2b. Sustained virological response was defined as hepatitis B e antigen seroconversion and hepatitis B virus DNA <10(5) copies/mL at week 72., Results: Twenty-nine patients were treated with 48 weeks of pegylated-interferon-alpha-2a and 24 patients with 24 weeks of pegylated-interferon-alpha-2b. At the end-of-therapy, hepatitis B e antigen seroconversion and hepatitis B virus DNA <10(5) copies/mL were similar between the two groups of patients [9/29 (31.0%) vs. 2/24 (8.3%), respectively, P = 0.09]. At week 72, 10 of the 29 patients (34.5%) treated with 48 weeks of pegylated-interferon-alpha-2a compared with two of the 24 patients (8.3%) treated with 24 weeks of pegylated-interferon-alpha-2b had sustained virological response (P = 0.04). By logistic analysis, 48 weeks of pegylated-interferon-alpha-2a was independently associated with sustained virological response (P = 0.04 adjusted hazards-ratio 9.37)., Conclusion: Further studies are required to determine the optimal duration of therapy with pegylated interferons in chronic hepatitis B.

Background & Aims: Hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) is a unique episomal replicative intermediate responsible for persistent infection of hepatocytes. Technical constraints have hampered the direct study of cccDNA maintenance and clearance mechanisms in patients. The aim of this study was to develop a sensitive and specific assay for quantifying cccDNA in biopsy samples from chronic hepatitis B patients during different natural history phases and in patients undergoing antiviral therapy., Methods: Intrahepatic cccDNA levels were quantified by a specific real-time PCR assay. Ninety-eight liver biopsy samples from patients in the major phases of the natural history of chronic hepatitis B and 32 pairs of samples from patients receiving adefovir dipivoxil (ADV) therapy were assessed., Results: cccDNA was detected, at levels ranging over 3 orders of magnitude, in patients in different phases of the natural history of chronic hepatitis B. cccDNA levels were strongly correlated with levels of total intracellular HBV DNA and serum HBV DNA. Forty-eight weeks of ADV therapy resulted in a significant 0.8 log decrease in cccDNA copies/cell. Changes in cccDNA were correlated with a similar reduction in serum HBsAg titer but not with a decrease in the number of HBV antigen-positive cells during ADV treatment., Conclusions: cccDNA persists throughout the natural history of chronic hepatitis B, even in patients with serologic evidence of viral clearance. Long-term ADV therapy significantly decreased cccDNA levels by a primarily noncytolytic mechanism.

Background: Lamivudine (LMV) is the only nucleoside analogue approved for the treatment of chronic hepatitis B (CHB). LMV, as with other nucleoside analogues including Famciclovir (FCV), suppresses the replication of hepatitis B virus (HBV) by targeting the viral polymerase. However, prolonged antiviral therapy results in the emergence of drug resistance HBV which can contribute to virological breakthroughs and recurrent hepatitis flares., Objectives: A 38-year-old hepatitis B e antigen (HBeAg) positive Chinese female infected with genotype B HBV commenced treatment with FCV and LMV combination therapy but was later maintained on LMV monotherapy. The patient remained HBeAg positive throughout treatment. Virological breakthrough occurred with the emergence of drug resistant HBV. This coincided with worsening liver function and the patient died of subacute fulminant hepatitis. This study evaluated the virological factors that contributed to the clinical decline of the patient., Study Design: Biochemical analysis and full-length HBV genomic sequencing were performed on serial serum samples collected from the patient before and during antiviral therapy., Results: Virological analysis revealed that the pre-treatment dominant HBV quasispecies in the patient had a number of non-consensus genotype B mutations which were located in the basal core promoter (BCP), polymerase, X, core and S genes. Subsequent to the instigation of antiviral therapy, the dominant drug resistant HBV which caused virological breakthrough and was associated with hepatic failure displayed a series of unique mutations particularly in the BCP (A1762T and G1764A) and in the polymerase (rtL180M, rtM204V, rtA222T and rtL336V), core (cP5T, cS26A, cV85I and cP135A), surface (sI195M and sM213I) and X (xK95Q, xN118T, xK130M and xV131I) proteins., Conclusions: Monitoring for the accumulation of unique mutations within the genome of drug resistant HBV mutants isolated during long term antiviral therapy appears warranted in the clinical management of patients with CHB.

We examined whether combination therapy with thymosin-alpha1 and famciclovir would induce hepatitis B e antigen seroconversion in patients with chronic hepatitis B infection in the immune-tolerant phase without inducing significant hepatic necro-inflammation. We studied 32 hepatitis B e antigen positive patients in the immune-tolerant phase of infection, treated with 26-weeks combination therapy of famciclovir and thymosin-alpha1 (group 1). Thirty-two patients who received 26-weeks famciclovir monotherapy (group 2) and another 32 patients who received no treatment (group 3), served as controls. Peripheral blood mononuclear cell proliferation and cytokine secretion in response to recombinant HBV core and surface antigen and serial serum HBV-DNA, were assayed. No significant difference in adverse events were observed among the three groups. By week 26, the median reduction in group 1 (0.94 log10 copies/mL) was greater than group 2 (0.70 log10 copies/mL, P < 0.001). Five (15.6%) patients in group 1 at 52 weeks (median range 13-78 weeks) and none in group 2 or 3 experienced hepatitis B e antigen seroconversion (P = 0.053). Sustained serological clearance of hepatitis B e antigen was associated with activation of CD4 positive HBV-specific T-cell reactivity and were of T-helper 1. Hence combination therapy with immunomodulatory agents and nucleoside analogues should be explored.

In an endemic area for chronic hepatitis B infection, reactivation of this virus is a serious cause of morbidity and mortality in patients undergoing cytotoxic or immunosuppressive therapy. Careful prospective serological testing has shown that hepatitis B virus reactivation is a two-staged process. The initial stage occurs during intense cytotoxic or immunosuppressive therapy and is characterised by enhanced viral replication, as reflected by increases in the serum levels of hepatitis B virus DNA, hepatitis B e antigen, hepatitis B virus DNA polymerase and infection of naïve hepatocytes with hepatitis B virus. The second stage is related to restoration of immune function following withdrawal of cytotoxic or immunosuppressive therapy, which causes rapid immune-mediated destruction of infected hepatocytes. Clinically, this can lead to hepatitis, hepatic failure and even death. The occurrence and severity of hepatitis B virus reactivation after various cytotoxic or immunosuppressive therapy is unpredictable and treatment has been disappointing, largely due to the late administration of therapy. Recently, pre-emptive treatment of chronic hepatitis B patients undergoing cytotoxic or immunosuppressive therapy, with potent nucleoside analogues has shown some promising results. Further controlled studies are needed to define the incidence and risk factors of hepatitis B reactivation so that pre-emptive treatment with nucleoside analogues could be administered to those patients at high risk of disease., (Copyright 2001 John Wiley & Sons, Ltd.)

Chronic HBV infection is a serious health threat in the Asian-Pacific region. The introduction of lamivudine has greatly improved the hope of these patients and is undoubtly a milestone in the management of chronic HBV infection. The combination of lamivudine with another nucleotide or nucleoside analogue or immunomodulatory agent to improve its therapeutic efficacy further must be investigated. Also, the use of lamivudine to prevent HBV reactivation on withdrawal of immunosuppressive therapy should be explored.

In vitro studies have shown that lamivudine and penciclovir (the active metabolite of famciclovir) act synergistically to inhibit hepatitis B virus (HBV) replication. We compared the effectiveness of HBV viral suppression by lamivudine monotherapy versus lamivudine plus famciclovir combination therapy in Chinese patients with chronic HBV infection. Twenty-one Chinese hepatitis B e antigen (HBeAg)-positive patients, with detectable HBV DNA (Digene Hybrid Capture II), were randomized to receive either lamivudine 150 mg/d orally (group 1, 9 patients) or lamivudine 150 mg/d plus famciclovir 500 mg 3 times a day orally (group 2, 12 patients) for 12 weeks, with a follow-up period of at least 16 weeks. Serial serum HBV-DNA levels were determined and a mathematical model with provision for incomplete inhibition of virus production during therapy was applied to analyze the dynamics of viral clearance. The mean antiviral efficacy was significantly greater in group 2 than in group 1 (0.988 +/- 0.012 vs. 0.94 +/- 0.03, P =.0012). HBV DNA returned to pretreatment level within 16 weeks after the end of initial treatment in 4 patients (66.7%) in group 1 and none in group 2 (P =.08), who remained HBeAg positive and received no further treatment after week 12. Hence, in Chinese chronic HBeAg-positive patients, combination therapy using lamivudine and famciclovir was superior to lamivudine monotherapy in inhibiting HBV replication. Further studies of longer duration are needed to define whether combination therapy will increase the HBeAg seroconversion rate and decrease the rate of emergence of lamivudine-resistant variants.

Chronic hepatitis B virus (HBV) infection is a major health threat in Asia. In order to design a better therapeutic regimen, the underlying mechanism of HBV viral persistence must be understood. Immunological studies have found that impaired HBV virus-specific T cell reactivity is the major cause of chronic infection, whereas strong and multispecific T cell responses to HBV are associated with long-term control, but not elimination of the virus. Furthermore, in the serological clearance of hepatitis B surface antigen (HBsAg) in allogeneic haematopoietic cell transplantation, HBsAg seroconversion is associated with activation of the donor's hepatitis B core antigen-specific CD4+ T lymphocytes. This suggests that the donor's hepatitis B core antigen-specific CD4+ T cells provide 'intermolecular T cell help' for the HBsAg seroconversion. These findings are relevant to the future development of therapeutic vaccines or DNA vaccine as immunotherapy for chronic hepatitis B. Apart from interferon-alpha, thymosin alpha1 (Talpha1) has been investigated for treatment of chronic hepatitis B. Meta-analysis of 4 randomized controlled studies investigating the safety and efficacy of Talpha1 monotherapy for the treatment of chronic hepatitis B showed that 6 months treatment with Talpha1 (1.6 mg twice weekly) almost doubles the sustained response rate (36%) compared with controls (19%; P=0.04). However, more specific immunological approaches are being developed; notably, hepatitis B core antigen-based therapeutic vaccine was found to induce T cell proliferative responses in chronically infected hepatitis B patients to the T helper epitope included in the construct. However, the cytokine profile observed suggested the induction of a T helper 0/T helper 2 CD4+ T cell response rather than T helper 1 response. Thus, its combination with interferon-gamma or interleukin-12, which might reverse the CD4+T cell response, should be considered. In the future, it is likely that different types of combination therapy may have to be tailor-made for chronic HBV infection with different virological and immunological profiles and different degrees of liver damage.

Background: A double variant in the basal core promoter, converting nucleotide 1762 from A to T (T1762) and nucleotide 1764 from G to A (A[764), has been described in patients with chronic hepatitis B infection. Its prevalence and significance in Chinese chronic HBV carriers are unknown., Methods: We studied 177 Chinese patients with chronic HBV infection (chronic hepatitis/asymptomatic: 89/88; hepatitis B e antigen positive/negative: 84/93). The double variant was detected by mismatched polymerase chain reaction and restriction fragment length polymorphism analysis. The reliability of this method was verified by sequencing in 41 serum samples with 100% matching., Results: The double variant T1762/ A1764 was found in 52 of 89 patients with chronic hepatitis, but in only 6 of 59 asymptomatic carriers (p<0.001). The prevalence was significantly lower in hepatitis B e antigen positive patients (23/84) than in hepatitis B e antigen negative patients (35/64) (p<0.005). Precore variant, A1896 was detected in 40 individuals; 31 of them suffered from chronic hepatitis and 9 were asymptomatic (p<0.001). A combination of both variants T1762/A1764 and A1896 was seen in 3 of 59 asymptomatic and 22 of 89 patients with chronic hepatitis (p<0.005)., Conclusions: Mismatched polymerase chain reaction with restriction fragment length polymorphism provides a reliable, easy and fast method for detection of the presence of the T1762/A1764 variant. In Chinese chronic hepatitis B carriers, T1762/A1764 variant was associated with both active liver disease and hepatitis B e antigen negativity.

Background: Serological clearance of hepatitis B surface antigen (HBsAg) has been described after reception of hepatitis B surface antibody positive marrow, via allogeneic bone marrow transplantation (BMT). Histological changes during the clearance of HBsAg are unknown., Methods and Results: We described two chronic hepatitis B carriers (both hepatitis B e antigen negative), who cleared HBsAg after allogeneic bone marrow transplantation. Both received hepatitis B surface and core antibody positive human leucocyte antigen identical donors' marrow and had serological clearance of HBsAg 15 and 7 weeks after allogeneic BMT, respectively. Both events were preceded by hepatic flare. Both patients were also treated with famciclovir for the prevention of hepatitis B reactivation after BMT. Histological examination during the flare showed only mild necroinflammatory activity with multiple foci of confluent necrosis, associated with moderate lymphocytic infiltration. The majority of these lymphocytes were cluster of differentiation (CD) 8 positive. Using immunohistochemistry, there was no detectable hepatic expression of hepatitis B core antigen. However, HBsAg was positive, mainly in the area of confluent necrosis. Using in situ hybridization, hepatitis B virus (HBV) DNA was detected in the nucleus of 5% of hepatocytes, but not in the cytoplasm., Conclusions: At their last follow up, 22 and 16 months after BMT, the serum of both patients remained HBsAg negative, hepatitis B surface antibody positive and HBV-DNA negative by branched DNA assay.

In places where hepatitis B virus (HBV) infection is endemic, it is often necessary to give chemotherapy to or perform bone marrow transplantation for cancer patients who are also chronic HBV carriers. When standard chemotherapy was given to lymphoma patients, elevation of liver transaminases was observed in nearly half of those who were chronic HBV carriers. Ten percent of them became jaundiced, and the overall liver-related mortality was about 5%. There is currently no reliable way to predict the severity of HBV reactivation after chemotherapy. The risk is probably higher when the chemotherapy used is significantly immunosuppressive and the viral load in the liver is high. Different strategies have been used in an attempt to reduce the risk of HBV reactivation after chemotherapy, but they have not been very successful. Further studies will be required to determine the impact of newly available antiviral agents that are active against HBV. Recipients who are carriers of HBV or who receive hepatitis B surface antigen (HBsAg)-positive marrow are at increased risk of hepatitis B-related morbidity and mortality after bone marrow transplantation (BMT). There is evidence to suggest that prophylactic use of an active antiviral agent, such as famciclovir, may result in a significant decrease in the incidence and severity of HBV reactivation after BMT. Sustained serologic clearance of chronic HBV infection has also been reported in many HBsAg-positive marrow recipients receiving hepatitis B surface antibody-positive marrow from their allogeneic donors. There seems to be a transfer of both humoral and cellular immunity against HBV from donors to recipients. Further prospective studies are required to define the best approach to manage HBsAg-positive cancer patients receiving chemotherapy or BMT. It is recommended that all cancer patients be checked for their hepatitis B status before receiving chemotherapy or a bone marrow transplant, especially if they reside in or come from endemic areas of HBV infection.

In chimpanzees and in vitro cell culture studies, hepatitis C infection has been shown to suppress hepatitis B virus expression. In addition, hepatitis C infection can cause much more severe liver disease in patients chronically infected with hepatitis B virus. The aims of the present study were to determine the prevalence of hepatitis C infection in asymptomatic chronic hepatitis B Hong Kong Chinese patients and the histological changes and hepatic expression of hepatitis B virus and hepatitis C virus. Five hundred and seventy-one Hong Kong Chinese asymptomatic chronic hepatitis B patients were studied. Only four (0.7%) were hepatitis C virus antibody positive; they were also all positive for hepatitis C viral RNA in serum by reverse transcription-polymerase chain reaction (RT-PCR). Portal lymphoid aggregates and bile duct damage was noted in the liver sections of three of the four patients. Hepatic expression of hepatitis B surface antigen was detected in three patients; none had detectable hepatitis B core antigen. By branched DNA assay, serum hepatitis B DNA could not be detected in any of the four patients, but three had hepatitis C RNA. By in situ RT-PCR, hepatitis C RNA was detected in the cytoplasm of three of the four patients. These findings suggest that hepatitis C coinfection in asymptomatic chronic hepatitis B patients is uncommon in Hong Kong Chinese and active hepatitis B viral replication is absent in these patients.