Treatment of chronic hepatitis B: case selection and duration of therapy

siRNA nanotherapeutics: a promising strategy for anti‐HBV therapy

Chronic hepatitis B (CHB) is the most common cause of hepatocellular carcinoma (HCC) and liver cirrhosis worldwide. In spite of the numerous advances in the treatment of CHB, drugs and vaccines have failed because of many factors like complexity, resistance, toxicity, and heavy cost. New RNA interference (RNAi)‐based technologies have developed innovative strategies to target Achilles' heel of the several hazardous diseases involving cancer, some genetic disease, autoimmune illnesses, and viral disorders particularly hepatitis B virus (HBV) infections. Naked siRNA delivery has serious challenges including failure to cross the cell membrane, susceptibility to the enzymatic digestion, and excretion by renal filtration, which ideally can be addressed by nanoparticle‐mediated delivery systems. cccDNA formation is a significant problem in obtaining HBV infections complete cure because of strength, durability, and lack of proper immune response. Nano‐siRNA drugs have a great potential to address this problem by silencing specific genes which are involved in cccDNA formation. In this article, the authors describe siRNA nanocarrier‐mediated delivery systems as a promising new strategy for HBV infections therapy. Simultaneously, the authors completely represent the clinical trials which use these strategies for treatment of the HBV infections.

A modified thymosin alpha 1 inhibits the growth of breast cancer both in vitro and in vivo: suppressment of cell proliferation, inducible cell apoptosis and enhancement of targeted anticancer effects

Thymosin alpha 1 (Tα1) is commonly used for treating several diseases; however its usage has been limited because of poor penetration of the target tissue, such as tumor cells. In the present study, Tα1-iRGD, a peptide by conjugating Tα1 with the iRGD fragment, was evaluated its performance in MCF-7 and MDA-MB-231 human breast cancer cells. Compared with the wild-type peptide, Tα1-iRGD was more selective in binding tumor cells in the cell attachment assay. Furthermore, the MTT assay confirmed that Tα1-iRGD proved more effective in significantly inhibiting the growth of MCF-7 cells in contrast to the general inhibition displayed by Tα1. Further, conjugation of Tα1 with iRGD preserved the immunomodulatory activity of the drug by increasing the proliferation of mouse spleen lymphocytes. Further, compared with Tα1 treatment, Tα1-iRGD treatment of MCF-7 cells considerably increased the number of cells undergoing apoptosis, resulting in a dose-dependent inhibition of cancer cell growth, which was associated with a much better effect on up-regulation of the expression of BCL2-associated X protein (Bax), caspase 9, etc. More importantly, treatment with Ta1-iRGD was more efficacious than treatment with Ta1 in vivo. This study highlights the importance of iRGD on enhancement of cell penetration and tumor accumulation. In summary, our findings demonstrate that the novel modified Tα1 developed in this study has the potential to be used for treating breast cancer.

Prevention of hepatitis B virus-associated liver diseases by antiviral therapy

Hepatitis B virus (HBV) is a major cause of acute and chronic hepatitis, cirrhosis and hepatocellular carcinoma, particularly in Asia-Pacific countries. The major complications in HBV carriers are hepatocellular carcinoma (HCC), liver failure and esophageal varices following the progression to cirrhosis, while some develop HCC without cirrhosis. The progression to liver fibrosis and these other complications could be prevented by treatment with nucleos(t)ide analogues (NUCs); however, NUCs must be continuously administered for a long time. Peginterferon could lead to HBV surface antigen loss. It is difficult to use peginterferon in HBV-infected patients with decompensated cirrhosis. Acute liver failure due to HBV infection and acute exacerbation of chronic hepatitis B could be treated by NUCs. Universal vaccination programs against HBV could prevent new HBV infections globally. Here, we review the currently available treatments for HBV infection.

Pre-existing mutations in reverse transcriptase of hepatitis B virus in treatment-naive Chinese patients with chronic hepatitis B

High rate of viral replication and lacking of proofreading activity in hepatitis B virus (HBV) polymerase lead to the generation of mutations in HBV virus. Mutations in the reverse transcriptase (RT) region of HBV polymerase are demonstrated to be strongly associated with drug resistance during antiviral treatment. However, the presence of mutations as well as its clinical significance in treatment-naïve hepatitis patients (defined as pre-existing mutations) need to be further investigated. In the present study, a total of 168 serum samples from treatment-naive chronic hepatitis B (CHB) patients were collected, and the RT region of HBV polymerase was sequenced. The results showed that pre-existing mutations in the RT region of HBV polymerase were detected in 43 of 168 (25.6%) treatment-naive CHB patients within which there were no well-characterized primary nucleotide analogs (NAs) resistance sites. Three dominant sites at rt191, rt207 and rt226 were found mutant in 7(16.28%), 8(18.60%), and 14(32.56%) samples respectively among these 43 patients. No significant correlation was found between pre-existing mutations and gender, age, HBV genotype, ALT, HBeAg or HBV DNA loads. However, patients with pre-existing RT mutations under HBeAg sero-negative status exhibited decreased HBV DNA loads, which contributed to the decreased HBV DNA loads in the total HBeAg sero-negative patients. The above investigation indicated that there was a prevalence of pre-existing mutations in RT region of HBV polymerase which might affect the serum HBV DNA level in treatment-naive CHB patients. Its effects on the occurrence of NAs resistance and the prognosis after treatment need to be further investigated.

High dose of Lamivudine and resistance in patients with chronic hepatitis B

Background. Lamivudine is the most affordable drug used for chronic hepatitis B and has a high safety profile. With the daily dose of 100 mg there is progressive appearance of resistance to lamivudine therapy. In our study we used 150 mg of lamivudine daily as a standard dose which warrants further exploration for the efficacy of the drug. Aims of the Study. To assess the efficacy of lamivudine 150 mg daily on resistance in patients with chronic hepatitis B. Methods. This retrospective study consists of 53 patients with chronic hepatitis B treated with 150 mg of lamivudine daily. The biochemical and virological response to the treatment were recorded at a 1-year and 2-, 3-, 4-, and 5-year period and time of emergence of resistance to the treatment was noted. Results. The mean age of the patients was 54 years with 80% being males. The resistance to lamivudine 150 mg daily at 1 year and 2, 3, and 5 years was 12.5%, 22.5%, 37.5%, and 60%, respectively, which is much less compared to the standard dose of 100 mg of lamivudine. Conclusions. Lamivudine is safe and a higher dose of 150 mg daily delays the resistance in patients with chronic hepatitis B.

HBV genotype B/C and response to lamivudine therapy: a systematic review

A number of nucleoside analogues such as lamivudine (LAM), actually used for the treatment of chronic hepatitis B, can suppress HBV DNA replication, improve transaminase level and liver histology, and enhance the rate of hepatitis B e antigen (HBeAg) clearance. The responses to LAM therapy involve HBeAg clearance and HBV DNA conversion of negative. However, the associations between HBV genotype B/C and response to LAM therapy remain ambiguous. The aim of this meta-analysis is to determine more precise estimations of the relationship. All the publications on the associations between HBV genotype B/C and response to LAM (HBeAg clearance and HBV DNA conversion of negative) through June 2013 were collected. Relative risk (RR) with 95% confidence intervals (95% CI) was calculated in fixed or random model, I² was calculated to examine heterogeneity, and funnel plots were plotted to examine small study effects with Stata 11 software. Overall, for HBeAg clearance and genotype B/C, the RR (95% CI) was 1.27 (0.94–1.71), while for HBV DNA conversion of negative and genotype B/C, the RR (95% CI) was 1.07 (0.98–1.17). HBV genotype B/C shows no significance associations with response to lamivudine therapy (HBeAg clearance and HBV DNA conversion of negative).

A new class of pyrimidine nucleosides: inhibitors of hepatitis B and C viruses

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are major health threats worldwide leading to liver cirrhosis, liver cancer and mortality. Herein, we report a new category of dideoxy pyrimidine nucleosides possessing a 4'-carboxyl (or carboxymethyl) function (7-9, 13, 16, 17), which are discovered as potential antiviral agents. For the first time, these nucleosides are recognized to be inhibitors of HBV and/or HCV replication. Among 4'-carboxy compounds, 3',4'-didehydrothymidine (16) was most effective against DHBV, HBV and HCV. Modification of the 4'-position in compound 7 from a carboxyl to carboxymethyl group (17) did not affect the anti-HBV activity but greatly increased the anti-HCV activity. Importantly, 17 yielded synergistic antiviral effect when combined with ribavirin without toxicity. The activity exhibited by a single agent towards both hepatitis viruses and no detectable in vitro cytotoxicity make this new class of compounds of interest.

Hepatitis B virus infection: pathogenesis, reactivation and management in hematopoietic stem cell transplant recipients

Hepatitis B virus (HBV) is a partially double stranded DNA virus that can integrate into host cell chromosomes as covalently closed circular DNA forms. HBV reactivation following hematopoietic stem cell transplantation in recipients with evidence of past HBV exposure, as well as exacerbation of a current HBV infection in HBV carrier recipients, secondary to chemotherapy and post-transplant immunosuppression that affect both humoral and cell-mediated control of HBV infection, are well documented in the literature. Management options include HBV-DNA screening and antiviral prophylaxis. Nucleos(t)ide analogues have been used at the start of chemotherapy and pretransplantation, with the course continuing for 6 months. However, depending on the serum HBV-DNA level, the antiviral agent might be given until a therapeutic end point is reached.

Development and validation of a model to predict advanced fibrosis in chronic hepatitis B virus-infected patients with high viral load and normal or minimally raised ALT

BACKGROUND/AIMS

Treating a group of chronic hepatitis B virus (HBV)-infected patients with high viral load and advanced fibrosis or cirrhosis, regardless of their serum alanine aminotransferase (ALT) levels, is recommended. The aim of this study was to derive and validate a model to predict advanced fibrosis in a cohort of patients with viral replication and normal or minimally raised ALT [ALT < 2 × upper normal limit (UNL)].

METHODS

Information was collected from 124 patients who underwent liver biopsy. The diagnostic value of predictors was judged using multivariate logistic modeling and area under the receiver operating characteristic curves (ROC area).

RESULTS

Advanced fibrosis (F3 or F4 on METAVIR scoring schema) was diagnosed in 45.7% (95% CI, 34-57.4%) of the patients of the derivation set (70 patients) and in 37% (95% CI, 24.2-49.9%) of the validation set (54 patients). In the derivation set, age and aspartate aminotransferase (AST) were independent clinical predictors of advanced fibrosis. The ROC areas of this Age-AST model were 0.8 (95% CI, 0.7-0.9) in the derivation set and 0.82 (95% CI, 0.71-0.93) in the validation set, respectively. Without missing a single case, this model identified 11 patients (20%) without advanced fibrosis in the validation set.

CONCLUSIONS

A substantial proportion of patients with high viral load and ALT < 2 × UNL have advanced fibrosis. A simple model including age and AST is an easily applicable tool for physicians to guide their decisions on whether or not to perform liver biopsy in individual patients.

Therapeutic vaccines and immune-based therapies for the treatment of chronic hepatitis B: perspectives and challenges

The treatment of chronic hepatitis B virus (HBV) infection has greatly improved over the last 10 years, but alternative treatments are still needed. Therapeutic vaccination is a promising new strategy for controlling chronic infection. However, this approach has not been as successful as initially anticipated for chronic hepatitis B. General impairment of the immune responses generated during persistent HBV infection, with exhausted T cells not responding correctly to therapeutic vaccination, is probably responsible for the poor clinical responses observed to date. Intensive research efforts are now focusing on increasing the efficacy of therapeutic vaccination without causing liver disease. Here we describe new approaches to use with therapeutic vaccination, in order to overcome the inhibitory mechanisms impairing immune responses. We also describe innovative strategies for generating functional immune responses and inducing sustained control of this persistent infection.

Expression, purification and characterization of a novel soluble human thymosin alpha1 concatemer exhibited a stronger stimulation on mice lymphocytes proliferation and higher anti-tumor activity

Thymosin alpha 1 (Tα1) has immunomodulatory and anti-tumor effects in patients and has been commercialized in worldwide. An innovative technique is therefore impending to achieve high-yield expression and purification of Tα1 to meet the increasing requirements for clinical applications. Tα1 can enhance T cells, dendritic cells and antibody responses, and also augment an anti-tumor immune response. In the current study, we developed a novel technique to produce Tα1 concatemer and investigated its capability in anti-tumor immunotherapy. We expressed the recombinant 2×Tα1 concatemer protein (Tα1② protein) in Escherichia coli. The purity of Tα1② was higher than 95% as assessed by HPLC analysis. In vitro, Tα1② could stimulate the proliferation of mouse splenic lymphocyte, and increase the apoptosis of tumor cell lines. In vivo, Tα1② significantly inhibited the tumor growth in B16 tumor-bearing mice. Compared with Tα1, the Tα1② is of more effective bioactivity than Tα1. The purified Tα1② is a promising substitute for synthetic Tα1 because of its potent anti-tumor effects. We concluded that the expression system for Tα1 concatemer was constructed successfully, which could serves as a highly efficient tool for the production of large quantities of the highly active protein.

Molecular methods in the diagnosis and management of chronic hepatitis B

Chronic hepatitis B (CHB) infection remains a major global problem but the recent advances in molecular methods have revolutionized the diagnosis and management of CHB. Hepatitis B virus (HBV) DNA quantitation is the most useful molecular marker for the diagnosis and management of CHB. There is increasing evidence that the clinical outcome and efficacy of antiviral therapy for CHB could vary with the infecting HBV genotype, core promoter and precore mutations. Early identification of drug resistance is imperative in the management of CHB. The molecular methods for HBV DNA quantitation, HBV genotyping, the identification of mutants, genotypic and phenotypic methods for monitoring drug resistance and their utility and limitations for use in the diagnosis and monitoring of CHB are discussed in this article.

Differential transcriptional responses to interferon-alpha and interferon-gamma in primary human hepatocytes

Interferon (IFN) plays a central role in the innate and adaptive antiviral immune responses. While IFN-alpha is currently approved for treating chronic hepatitis B and hepatitis C, in limited studies, IFN-gamma has not been shown to be effective for chronic hepatitis B or C. To identify the potential mechanism underlying the differential antiviral effects of IFN-alpha and IFN-gamma, we used cDNA microarray to profile the global transcriptional response to IFN-alpha and IFN-gamma in primary human hepatocytes, the target cell population of hepatitis viruses. Our results reveal distinct patterns of gene expression induced by these 2 cytokines. Overall, IFN-alpha induces more genes than IFN-gamma at the transcriptional level. Distinct sets of genes were induced by IFN-alpha and IFN-gamma with limited overlaps. IFN-alpha induces gene transcription at an early time point (6 h) but not at a later time point (18 h), while the effects of IFN-gamma are more prominent at 18 h than at 6 h, suggesting a delayed transcriptional response to IFN-gamma in the hepatocytes. These findings indicate differential actions of IFN-alpha and IFN-gamma in the context of therapeutic intervention for chronic viral infections in the liver.

Bioactivity and pharmacokinetics of two human serum albumin-thymosin alpha1-fusion proteins, rHSA-Talpha1 and rHSA-L-Talpha1, expressed in recombinant Pichia pastoris

Thymosin-alpha1 (Talpha1) is indicated for the treatment of certain viral infections, including hepatitis B and C, and cancers, such as melanoma. In this paper, the fusion genes encoding human serum albumin (HSA) and Talpha1 with (rHSA-L-Talpha1) and without a linker peptide (rHSA-Talpha1) were constructed and overexpressed in P. pastoris. Through the process of ion interaction chromatography (Q-Sepharose F.F), hydrophobic interaction chromatography (Phenyl Sepharose HP) and affinity chromatography (Blue Sepharose F.F), the purity of fusion proteins was greater than 97%. In contrast to the reactivity of normal spleen cells to Con A, the data of in vitro murine spleen lymphocytes proliferation experiment suggested that spleen cells achieved a higher degree of T cell maturation after rHSA-L-Talpha1, rHSA-Talpha1 and Talpha1 treatments, respectively. Moreover, rHSA-L-Talpha1, rHSA-Talpha1 and Talpha1 can also antagonize dexamethasone-induced apoptosis of thymocyte sub-populations. In hydrocortisone-induced immunosuppression mice (in vivo experiments), after subcutaneous injections with two fusion proteins and Talpha1 for seven consecutive days, the net increment of body weight, the spleen index and the thymus index were significantly improved. Simultaneously, the increase in SOD level and the decrease in MDA level in plasma were observed. The pharmacokinetic data of rHSA-L-Talpha1 and rHSA-Talpha1 administered in rats showed an improved pharmacokinetic profile with a conspicuous prolonged half life. The analysis of bioactivity and pharmacokinetics suggested that fusion proteins rHSA-L-Talpha1 and rHSA-Talpha1 were new drug candidates.

[Comparison of various noninvasive serum markers of liver fibrosis in chronic viral liver disease]

BACKGROUND/AIMS

The aim of this study was to determine the clinical performances of noninvasive serum markers for the prediction of liver fibrosis in chronic viral liver diseases.

METHODS

We analyzed a total of 225 patients with chronic viral liver diseases (180 with hepatitis B virus, 43 with hepatitis C virus, and 2 with hepatitis B+C virus) who underwent a liver biopsy procedure at the Hanyang University Guri Hospital between March 2002 and February 2007. Serum was also obtained at the time of liver biopsy. Liver fibrosis was staged according to the scoring system proposed by the Korean Study Group for the Pathology of Digestive Diseases. Various noninvasive serum markers were evaluated, including the aspartate aminotransferase (AST)/alanine aminotransferase (ALT) ratio (AAR), age-platelet (AP) index, AST/platelet ratio index (APRI), cirrhosis discriminant score (CDS), platelet count, hyaluronic acid (HA), and type IV collagen.

RESULTS

There were 17, 40, 61, 74, and 33 patients at stages F0, F1, F2, F3, and F4, respectively. The overall diagnostic accuracies of each marker, as determined by the area under receiver operating characteristics curves, were APRI=0.822, CDS=0.776, platelet count=0.773, AP index=0.756, HA=0.749, type IV collagen=0.718, and AAR=0.642 for predicting significant fibrosis (> or =F2); and CDS=0.835, platelet count=0.795, AP index=0.794, HA=0.766, AAR=0.711, type IV collagen=0.697, and APRI=0.691 for predicting extensive fibrosis (> or =F3).

CONCLUSIONS

All noninvasive serum markers evaluated in this study were useful for predicting significant or extensive liver fibrosis in chronic viral liver diseases. In particular, APRI was most useful for the prediction of significant fibrosis, and CDS was most useful for the prediction of extensive fibrosis.

Inhibition of the replication of hepatitis B virus in vitro by oxymatrine

This study investigated the inhibitory capacity of oxymatrine on in vitro hepatitis B virus (HBV) replication. HepG2.2.15 cells were treated with oxymatrine 50, 100, 200, 400, 800 or 1000 mg/l, or with human interferon-alpha2b (IFN-alpha2b 1000 U/l) as a positive control. Levels of hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg) and HBV-DNA in cell supernatants were determined by enzyme-linked immunosorbent assay and fluorescent quantitative-polymerase chain reaction, respectively. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometric analysis and terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick-end labelling were used to evaluate the cytotoxicity of oxymatrine. The inhibitory effects of oxymatrine gradually increased as the concentration increased from 200 to 1000 mg/l for HBsAg and HBeAg, and from 200 to 400 mg/l for HBV-DNA. There was no inhibitory effect of oxymatrine at concentrations < 200 mg/l. No significant difference was seen between human IFN-alpha2b (positive control) and oxymatrine >or= 200 mg/l. It is concluded that oxymatrine can inhibit in vitro HBV replication and antigen expression at concentrations >or= 200 mg/l.

Rapid HBV DNA decrease (week 12) is an important prognostic factor for first-line treatment with adefovir dipivoxil for chronic hepatitis B

BACKGROUND

The aim of the study was to estimate the effect of viral factors (HBV genotype, viral load and kinetics) to treatment response in chronic hepatitis B (CHB) and first-line therapy with adefovir dipivoxil (ADV).

METHODS

Sixty-six patients (60% males, 65% HBeAg negative) were treated with 10 mg ADV QD. Quantitative HBV DNA and ALT levels were determined at weeks 4, 12, 24, 48, 72 and 96. Nonresponse or viral resistance to ADV was assessed in patients with either persistent elevated HBV DNA levels (week 24) or with an increase in HBV DNA of at least 1 log after initial decline.

RESULTS

Most patients were infected with genotype D (66.7%; genotype A: 27.3%; genotype E: 6%); 86.4% achieved a virological (VR) and 54.5% a biochemical response (BR) in week 48, more often in patients with genotype A (P < 0.01). In week 96, BR increased to 60.5%, whereas a negative HBV DNA was observed in 83.3%. In 3% an ADV-induced viral resistance was detected. As an important predictive parameter for VR, a rapid decline of viral load at week 12 was observed. Of the patients with a negative PCR or drop of viral load of at least 3 log, 96% were still HBV DNA negative at the end of week 96; 77% of patients with a partial response achieved a VR. In contrast, no patient with nonresponse (week 12) reached a negative PCR at week 96 (P < 0.0001).

CONCLUSIONS

These results underline the importance of early viral kinetics to assess treatment response in CHB. In ADV nonresponders (week 12), an advanced antiviral therapy or switch to another nucleoside analogue should be considered.

Efficacy of pre-S-containing HBV vaccine combined with lamivudine in the treatment of chronic HBV infection

Treatment of chronic hepatitis B (CHB) is difficult. The response rate to interferon (IFN) as well as nucleoside analogs is not more than 30% in general. While interferon has many side effects, development of resistance in most of the nucleoside analogs precludes long-term use. Both groups of drugs are most efficacious in patients who already had or develop strong cellular immunity with treatment. A pre-S2-containing vaccine was shown to enhance cellular immunity and suppress hepatitis B virus (HBV)-DNA in subjects with chronic hepatitis B. We aimed to test the efficacy of short-term use of a nucleoside analog in combination with a pre-S2-containing vaccine in patients with CHB. In this open study, 48 consecutive patients (32 males and 16 females, mean age +/- SD: 33 +/- 12 years) with CHB without cirrhosis were treated with 100 mg/day lamivudine and four weekly intramuscular injections of Genhevac B 20 mcg (six doses) for 24 weeks. While 19 patients were hepatitis B e antigen (HBeAg) positive (+ve), 29 patients were Anti-HBe/HBV-DNA +ve at the outset. Response was defined as seroconversion to anti-HBe in HBeAg +ve subjects and normalization of alanine aminotransferase (ALT) with loss of HBV-DNA in anti-HBe/HBV-DNA +ve subjects. HBeAg seroconversion occurred in 5/19 subjects (26%). Eighteen of 29 anti-HBe/HBV-DNA +ves responded. In the follow-up, while relapse was not observed in any of the patients who seroconverted, 11/18 from the anti-HBe/HBV-DNA +ve group relapsed, resulting in a sustained response (SR) rate of 24% in this group. All the relapses happened in the first 48 weeks of follow-up, with no relapse thereafter. Pretreatment high serum HBV-DNA was a strong negative predictor of sustained response (SR) in HBeAg +ve group. Pretreatment serum ALT over 2 x upper limit of normal and HBV-DNA less than 200 pg/ml appeared positive predictors. None of HBeAg +ve previous interferon failures responded. Twenty-four weeks of lamivudine and hepatitis B vaccine treatment induces SR in around 1/4 of the patients with CHB. Most of the responders had high ALT and relatively low DNA.

Treatment with lamivudine versus lamivudine and thymosin alpha-1 for e antigen-positive chronic hepatitis B patients: a meta-analysis

BACKGROUND

Currently, there is no evidence on the combination of lamivudine and thymosin alpha-1 on chronic hepatitis B patients. The aim of this study was to compare the effect of lamivudine monotherapy with that of lamivudine and thymosin alpha-1 combination therapy for the treatment of hepatitis B e antigen (HBeAg)-positive hepatitis B patients.

RESULTS

We searched PUBMED (from 1966 onwards), EMBASE (from 1966), CBMdisk (Chinese Biomedical Database, from 1978), CNKI (National Knowledge Infrastructure, from 1980), the Cochrane Central Register of Controlled Trials and the Cochrane Database of Systematic Reviews. Eight trials (583 patients in total) were identified. The lamivudine and thymosin alpha-1 combination treatment was significantly superior to lamivudine treatment in terms of ALT normalization rate (80.2% vs. 68.8%, P = 0.01), virological response rate (84.7% vs. 74.9%, P = 0.002), and HBeAg seroconversion rate (45.1% vs. 15.2%, P < 0.00001).

CONCLUSION

Among HBeAg-positive patients, thymosin alpha-1 and lamivudine combination therapy may be more effective than lamivudine monotherapy, providing superior rates of biochemical response, virological response, and HBeAg seroconversion.

Sustained response to peginterferon alfa-2a (40 kD) with or without lamivudine in Asian patients with HBeAg-positive and HBeAg-negative chronic hepatitis B

PURPOSE

The 2 reported trials investigated the effectiveness of treatment with peginterferon alfa-2a in Asian patients with chronic hepatitis B (CHB).

METHODS

Patients with HBeAg-positive (n = 708) or HBeAg-negative (n = 332) CHB were enrolled in 2 randomized, double blind, placebo-controlled studies. Patients received peginterferon alfa-2a 180 mug once weekly, peginterferon plus lamivudine 100 mg per day, or lamivudine alone for 48 weeks. Patients were followed up at 6 and 12 months posttreatment.

RESULTS

Peginterferon alfa-2a provided significantly higher rates of HBeAg seroconversion (31%) in HBeAg-positive patients than did lamivudine (19%, P = 0.005) 6 months posttreatment, irrespective of genotype. Of these, 83% achieving seroconversion during treatment or early posttreatment sustained their response at 12 months posttreatment. In patients who seroconverted, 69% maintained HBV DNA suppression at <10,000 copies/ml and alanine aminotrasferase (ALT) normalization. In HBeAg-negative patients, peginterferon produced a significantly higher combined response of HBV DNA at <20,000 copies/ml and ALT normalization (45%) than lamivudine (31%, P = 0.032), irrespective of genotype. Almost 80% of these patients sustained their response at 12 months posttreatment.

CONCLUSIONS

In conclusion, a finite course of peginterferon alfa-2a provides significant and sustained treatment benefit in Asian CHB patients, who have traditionally been regarded as difficult to treat.

HBeAg and hepatitis B virus DNA as outcome predictors during therapy with peginterferon alfa-2a for HBeAg-positive chronic hepatitis B

The aims of this study were to evaluate the usefulness of quantitative hepatitis B e antigen (HBeAg) values for predicting HBeAg seroconversion in patients treated with peginterferon alfa-2a and to assess the dynamic changes in quantitative HBeAg during therapy, compared with conventional measures of serum hepatitis B virus DNA. Data were analyzed from a large, randomized, multinational phase III registration trial involving 271 HBV-infected HBeAg-positive patients who received peginterferon alfa-2a plus oral placebo for 48 weeks. HBeAg levels were measured serially during therapy using a microparticle enzyme immunoassay validated with in-house reference standards obtained from the Paul Ehrlich Institute (PEIU/mL). In patients who achieved HBeAg seroconversion, levels of HBeAg consistently decreased during treatment and remained at their lowest level during the 24 weeks of posttreatment follow-up. After 24 weeks of treatment, 4% of patients with the highest levels of HBeAg (>or=100 PEIU/mL) achieved HBeAg seroconversion, yielding a negative predictive value of 96%, which was greater than that obtained for levels of HBV DNA (86%). Late responders to peginterferon alfa-2a could also be differentiated from nonresponders by continued decrease in HBeAg values, which were not evident by changes in HBV DNA.

CONCLUSION

These analyses suggest quantitative HBeAg is a useful adjunctive measurement for predicting HBeAg seroconversion in patients treated with peginterferon when considering both sensitivity and specificity compared with serum HBV DNA.

Therapeutic efficacy of sequential and simultaneous treatments with interferon-alpha and lamivudine in children with chronic hepatitis B

BACKGROUND

Interferon (IFN)-alpha and lamivudine (LAM), a nucleoside analog, are frequently used drugs for the treatment of chronic hepatitis B (CHB), and their combined therapy has been shown to be effective. The purpose of the present study was to examine the therapeutic efficacy of sequential and simultaneous combination therapies of IFN-alpha and LAM in children with CHB.

METHODS

A total of 45 children with CHB, whose antibody status was positive for hepatitis B surface antigen (HBsAg), hepatitis B envelope antigen (HBeAg), and HBV-DNA at least for 6 months; who had alanine aminotransferase (ALT) levels 1.5-fold higher than normal and hepatic activity index scores higher than 6, were allocated to two groups. The first group included 24 children who were given standard dose IFN-alpha (5 MU/m(2) s.c., thrice weekly) for 6 months, followed by LAM (4 mg/kg per day per oral, maximum 100 mg/day) for an additional 6 months (sequential therapy group). The second group included 21 children who were given IFN-alpha and LAM therapy simultaneously for 6 months and who continued with LAM alone for another 6 months (simultaneous therapy group). Partial response was defined as normalization of ALT and eradication of HBV-DNA. Complete response was defined as normalization of ALT, eradication of HBV-DNA and e seroconversion. Non-responders were defined as having positive HBV-DNA and abnormal ALT levels. Sustained response was defined as absence of HBsAg and presence of hepatitis B surface antibody (anti-HBs).

RESULTS

The mean age of the sequential therapy group was 12.7 +/- 4.1 years, and 16 (66.7%) of the patients were male. The mean age of the simultaneous therapy group was 14.8 +/- 4.6 years, and 15 (71.4%) were male. In the first group, 13 patients (54.2%) were non-responders; partial response was observed in five patients (20.8%), and complete response was seen in six patients (25%). Despite the occurrence of e seroconversion, normalization of ALT was not achieved in one case. In the second group, which consisted of 21 patients, 11 subjects (52.4%) were non-responders; partial response was observed in one case (4.8%), and complete response was seen in seven (33.3%). Sustained response was found in two patients (9.5%). There were no significant differences between the groups (P > 0.05).

CONCLUSION

When the therapeutic efficiency of two different treatment regimens applied for 1 year was evaluated in childhood CHB therapy, it was remarkable that there was a sustained response and a higher complete response in group 2, although there was no considerable difference between the therapy results of both groups.

Molecular epidemiology of Hepatitis B virus genotypes in Pakistan

Background

Eight genotypes of Hepatitis B virus designated A-H, have been known but in Pakistan, no such data is available on the prevalent HBV genotypes. Therefore, the subject study was conducted to determine HBV genotypes in the indigenous Pakistani population.

Methods

A total of 690 individuals were enrolled for HBV screening with EIA and nested PCR. Positive samples were further analyzed to determine HBV genotypes (A-F) by multiplex-PCR using type specific primers.

Results

110 (15.94%) individuals were positive for HBV, including 64% males and 36% females. Out of these, 66 samples (65.34%) were classified into genotype D, 27 (26.73%) were of genotype B while 5(4.95%) had genotype A. In 3 (2.98%) samples, multiple genotypes were detected (genotype A+B; 2(1.99%) and genotypes B+D; 1(0.99%). Nine (8.18%) samples remained untyable.

Conclusion

In Asia, genotypes B and C are the most prevalent but our study reveals that genotype D is predominant and HBV infection constitutes a significant health problem in Pakistan.

Thymosin-alpha1 modulates dendritic cell differentiation and functional maturation from human peripheral blood CD14+ monocytes

Although thymosins have been demonstrated to have immunomodulatory effects, it is still not clear whether they could affect dendritic cells (DCs), the most professional antigen-presenting cells. The objective of this study was to determine the effect and potential mechanisms of thymosin-alpha1 (Talpha1) on DC differentiation and functional maturation. Human peripheral blood CD14(+) monocytes were purified by using a magnetic separation column and cultured with GM-CSF and IL-4 to differentiate into immature DCs (iDCs). In the presence of Talpha1, iDC surface markers CD40, CD80, MHC class I and class II molecules were significantly upregulated as measured by flow cytemotry analysis. However, Tbeta4 or Tbeta10 did not show these effects on iDCs. There was an approximately 30% reduction in antigen (FITC-conjugated dextran)-uptake by Talpha1-treated iDCs as compared with non-Talpha1-treated iDCs. In addition, Talpha1-treated matured DCs (mDCs) showed an increased stimulation of allogeneic CD3(+) T-cell proliferation as measured by a mixed-lymphocyte reaction assay. Talpha1-treated mDCs also increased the production of several Th1- and Th2-type cytokines as measured by a Bio-Plex cytokine assay. Furthermore, rapid activation of p38 MAPK and NFkappaB was seen in Talpha1-treated iDCs as measured by a Bio-Plex phosphoprotein assay. Thus, Talpha1 significantly enhances DC differentiation, activation, and functions from human peripheral blood CD14(+) monocytes possibly through a mechanism of the activation of p38 MAPK and NFkappaB pathways. This study provides a basis to further evaluate Talpha1 as a possible adjuvant for a DC-directed vaccine or therapy.

Lamivudine prophylaxis and treatment of hepatitis B Virus-exposed recipients receiving reduced intensity conditioning hematopoietic stem cell transplants with alemtuzumab

Individuals with past exposure to hepatitis B virus (HBV) may reactivate HBV following bone marrow transplantation. Alemtuzumab (CAMPATH)-based reduced intensity conditioning bone marrow transplantation has been associated with a high incidence of viral infections. Lamivudine prophylaxis for HBV should be instituted in this setting. The management of 240 CAMPATH-based reduced intensity conditioning bone marrow transplantation, carried out over an 8-year period at Kings College Hospital, was reviewed. Hepatitis B core total antibody (anti-HBc) testing identified recipients and donors with previous HBV exposure. Fifteen donor-recipient pairs were identified as being at risk of HBV reactivation. Eight recipients of anti-HBc negative donors were HBsAg negative, anti-HBc positive pre-transplantation. Five anti-HBc negative recipients received transplants from HBsAg negative, anti-HBc positive donors. Two HBV carrier recipients had one anti-HBc negative and one positive donor, respectively. Pre-transplant lamivudine prophylaxis was given to 8/10 (80%) anti-HBc positive recipients. Although HBsAg and HBV DNA were detected 4 months after bone marrow transplantation in one patient who did not receive prophylaxis, a good antiviral response was documented on starting lamivudine. The two HBV carrier recipients had stopped lamivudine at 8 and 31 months post-bone marrow transplantation, respectively, and died of liver failure with a sharp rise in HBV DNA levels. The five anti-HBc negative recipients with anti-HBc positive donors remained HBsAg and HBV DNA negative. Although lamivudine prophylaxis prevented HBV reactivation, it is unclear at what stage post-transplantation prophylaxis can be discontinued. Close monitoring of liver function tests (LFTs), HBsAg, and HBV DNA must be undertaken even after stopping antiviral prophylaxis.

YMDD motif variants in inactive hepatitis B carriers detected by Inno-Lipa HBV DR assay

INTRODUCTION

Mutations of hepatitis B virus (HBV) polymerase, especially occurring at the highly conserved YMDD region, are related to resistance to lamivudine. Although these mutations are frequently secondary to lamivudine use, they can also occur naturally. The aim of the present study was to determine the prevalence of YMDD variants that exist naturally in patients who are inactive HBV carriers.

METHODS

Seventy-one adult inactive HBV carriers were studied. All of the patients were confirmed to have maintained normal alanine aminotransferase (ALT) values for one or more years by monitoring serum ALT levels at 3-monthly intervals. None of the patients received interferon or antiviral agents. YMDD variants were analyzed by the HBV Drug Resistance Line Probe assay (Inno-Lipa HBV-DR).

RESULTS

YMDD variants were detected in 13 (18.3%) of the 71 anti-HBe positive inactive HBV carriers. Of the 13 patients, 10 (76.9%) also had accompanying L180M mutation. The combination of wild type and YMDD variant HBV was present in 11 of 13 patients. In two patients, only YIDD and/or YVDD variants plus L180M were detected without the presence of wild YMDD motif.

CONCLUSION

Naturally occurring YMDD motif variants were detected at a high rate in a group of lamivudine-untreated inactive HBV carriers.

Correlation of hepatitis B virus YMDD mutations with the polymorphism of HLA alleles in patients with chronic hepatitis B virus infection

AIM: To investigate the relationship between HBV YMDD mutations and the polymorphism of human leukocyte antigen (HLA) alleles in patients with chronic hepatitis B virus (HBV) infection.

METHODS: Fluorescent hybridization biprobe PCR and melting curve assay (FH-PCR-MC) was used to determine HBV YMDD mutations in serum specimens from 142 patients with chronic HBV infection. HLA-A, B, and DRB1 alleles in peripheral blood mononuclear cells (PBMCs) were detected by polymerase chain reaction-sequence specific primer (PCR-SSP). The PBMCs were collected from 56 of the 142 patients.

RESULTS: YMDD mutations occurred in 56.3% of the 142 patients who received lumivudine treatment. The frequencies of HLA-B*58 and DRB1*03 alleles were significantly lower in YMDD mutation group in comparison with those in YMDD wild group (0.013 vs 0.094, P = 0.036; 0.000 vs 0.063, P = 0.024). The frequency of HLA-A*30 allele was markedly higher in YIDD group than that in YVDD group (0.158 vs 0.024, P = 0.034), while the frequency of HLA-A*33 allele was lower in YIDD group ( 0.119vs 0.000, P = 0.028).

CONCLUSION: YMDD mutation is associated with the polymorphism of HLA alleles in patients with chronic hepatitis B. Individuals with HLA-B*58 and DRB1*03 alleles may have resistance to YMDD mutation. Patients with HLA-A*30 allele may have a susceptibility to YIDD mutation, and those with HLA-A*33 allele are susceptible to YVDD mutation.

Expression, purification and characterization of the Hepatitis B virus entire envelope large protein in Pichia pastoris

The current HBsAg vaccine has performed a vital role in preventing the transmission of HBV during the past 20 years. However, a number of individuals still show no response or a low response to the vaccine. In the present study, the HBV envelope large protein gene was cloned into the eukaryotic expression vector pPIC9k and was subsequently expressed in the yeast Pichia pastoris. The HBV large protein (L protein) was produced and secreted into the medium, where some of the L protein formed particles. The soluble L protein and particles were purified by column chromatography and sucrose density gradient centrifugation. Western blot analysis demonstrated that the particle was composed of both HBV L and S protein. To compare the antigenicity of the L protein and HBsAg, rabbits were immunized with the soluble L protein and the commercially available HBV vaccine and the increasing level of antibodies was determined by ELISA. The results showed that the anti-HBsAg antibody, from rabbits injected with the L protein at a dose of 2 and 10microg, was detected on day 14, whereas rabbits vaccinated with 10 and 2microg HBsAg did not develop antibodies until day 21 and 28, respectively. The antibody level in groups inoculated with the L protein was approximately 50% higher than in the group injected with HBsAg using the same dose. Furthermore, 2microg L protein induced a significant and rapid anti-HBsAg antibody response than 10microg HBsAg. Therefore, we suggest that the L protein is an ideal candidate for a new generation HB vaccine to protect people from HBV infection.

Interferon signal transduction of biphenyl dimethyl dicarboxylate/amantadine and anti-HBV activity in HepG2 2.2.15

Biphenyl dimethyl dicarboxylate (DDB) is a hepatoprotectant, which is used as an adjuvant agent in a treatment for chronic hepatitis. Amantadine is an antiviral agent, which is utilized primarily in the treatment of influenza, but also, occasionally in the treatment of hepatitis C. In a previous study, we reported that DDB, coupled with amantadine, would exert an anti-HBV effect, via the induction of interferon-inducible gene expression in the HepG2 2.2.15 cell line. The primary objective of the present study was to determine whether or not DDB and/or amantadine exhibit anti-HBV properties, and what mechanisms of action might be involved in such properties. In our study, we were able to determine that DDB stimulates Jak/Stat signaling, and induces the expression of interferon alpha (IFN-alpha) stimulated genes, most notably 6-16 and ISG12. In addition, the antiviral effectors induced by IFN-alpha, PKR, OAS, and MxA, were regulated in the presence of DDB at its optimal concentration (250 microg/mL), to a degree commensurate with the degree of induction associated with the IFN-alpha treated group. Finally, we determined that the replication of pregenomic RNA and HBeAg was inhibited by DDB treatment, and this inhibition was maximized when coupled with the administration of amantadine (25 microg/mL). In conclusion, the results of this study demonstrated clearly that DDB, as well as the combination of DDB/amantadine, directly inhibited IFN-alpha signaling-mediated replication of HBV in infected hepatocytes, and thus may represent a novel treatment for chronic hepatitis B, which would be characterized principally by its improved safety over other treatment strategies.

A partially overlapping treatment course with lamivudine and interferon in hepatitis B e antigen-negative chronic hepatitis B

BACKGROUND

Treatment of patients with hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (CHBe-) with interferon or lamivudine alone is inefficient and reports of combination treatment with both drugs, equivocal so far.

AIM

To investigate the efficacy of a lamivudine-interferon combination therapy in 36 patients HBeAg-negative CHBe-.

METHODS

Lamivudine was administered from 1 to 12 months and interferon-alpha2b from 7 to 18 months. A historical control group of 36 CHBe- patients, matched for age and sex and treated with the same dosage of interferon-alpha2b was used. All patients were followed up for > or =12-month post-treatment.

RESULTS

The biochemical response rate at the end of treatment was 78% in lamivudine-interferon and 52.8% in interferon-control group (P = 0.026) and at 12-month post-treatment 38.9% and 22.2%, respectively (P = 0.125). Alanine aminotransferase normalization and serum HBV-DNA levels < or =30 000 cp/mL were observed in 50.0% of lamivudine-interferon-treated and 30.6% of interferon-treated patients at the end of treatment (P =0.093) and in 22.2% and 13.9% of patients, respectively, at 12-month post-treatment (P = 0.358). Moreover, alanine aminotransferase normalization and undetectable serum HBV-DNA (<400 cp/mL) was observed in 30.6% of lamivudine-interferon-treated and 8.3% of interferon-treated patients at the end of treatment (P = 0.017) and in 8.3% and 0% of patients, respectively, at 12-month post-treatment (P = 0.076).

CONCLUSIONS

In CHBe-, 12 months after ending a lamivudine-interferon partially overlapping 18-month combination course, 22% of patients still maintain normal alanine aminotransferase and HBV-DNA levels < or =30 000 cp/mL. However, a 12-month interferon monotherapy course may achieve similar responses.

Character of HBV (hepatitis B virus) polymerase gene rtM204V/I and rtL180M mutation in patients with lamivudine resistance

OBJECTIVES

To investigate the relationship between HBV (hepatitis B virus) polymerase gene 180 and 204 sites mutation and lamivudine resistance.

METHODS

One hundred forty-one patients with lamivudine resistance after lamivudine treatment and 60 chronic hepatitis B patients without lamivudine treatment were enrolled in this study. The serum HBV DNA mutation was analyzed by sequence detection via polymerase chain reaction (PCR). The sequences of the same patient were analyzed before and after lamivudine treatment.

RESULTS

One hundred and nine lamivudine resistance patients had HBV YMDD (tyrosine-methionine-aspartate-aspartate) mutation. Among them, 45 patients had rtL180M/M204V mutation (41.28%), 28 patients had rtL180M/M204I mutation (25.70%) and 36 patients had rtM204I mutation (33.02%). There were 6 patients with rtL180M mutation in 32 lamivudine resistance patients. Sixty chronic hepatitis patients without lamivudine treatment had no mutations.

CONCLUSIONS

HBV mutations, which play an important role in lamivudine resistance usually locate at polymerase gene 204 site; 180 site mutation was also observed in these patients. Evaluation of the anti-virus therapy by surveillance of the two sites mutations is of importance.

He Jie Tang in the treatment of chronic hepatitis B patients

AIM: To explore the effect of He Jie Tang (decoction for medication) on serum levels of T lymphocyte subsets, NK cell activity and cytokines in chronic hepatitis B patients.

METHODS: Eighty-five patients with chronic hepatitis B were divided randomly into two groups. Fifty patients in group I were treated with He Jie Tang (HJT) and 35 patients in group II were treated with combined medication. The levels of T-lymphocyte subsets (CD₃⁺, CD₄⁺, CD₈⁺), NK cell activity, cytokines (TNF-α, IL-8, sIL-2R) were observed before and after the treatment. Another 20 normal persons served as group 3.

RESULTS: The level of CD₄⁺ cells and NK cell activity were lower, whereas the level of CD₈⁺ cells in patients was higher than that in normal persons (t = 2.685, 3.172, and 2.754 respectively; P<0.01). The levels of TNF-α, IL-8, and sIL-2R in chronic hepatitis B patients were higher than those in normal persons (t = 3.526, 3.170, and 2.876 respectively; P<0.01). After 6 months of treatment, ALT, AST, and TB levels in the two groups were obviously decreased (t = 3.421, 3.106, and 2.857 respectively; P<0.01). The level of CD₄⁺ cells and NK cell activity were increased whereas the level of CD₈⁺ cells decreased (t = 2.179, 2.423, and 2.677 respectively; P<0.05) in group I. The levels of TNF-α, IL-8, and sIL-2R in group I were decreased significantly after the treatment (t = 2.611, 2.275, and 2.480 respectively; P<0.05) but had no significant difference in group II after the treatment (t = 1.906, 1.833, and 2.029 respectively; P>0.05). The total effective rate had no significant difference between the two groups (X² = 2.882, P>0.05) but the markedly effective rate was significantly different between the two groups (X² = 5.340, P<0.05).

CONCLUSION: HJT is effective in treating chronic hepatitis B. HJT seems to exert its effect by improving the cellular immune function and decreasing inflammatory cytokines in chronic hepatitis B patients. The function of HJT in protecting liver function in the process of eliminating virus needs to be further studied.

Current treatment and future directions in the management of chronic hepatitis B viral infection

The World Health Organization places hepatitis B virus (HBV) in the top 10 causes of death worldwide. It is estimated that there are over 400 million carriers of HBV as well. At least 20% to 30% of hepatitis B surface antigen (HBsAg) carriers will die of complications of chronic liver disease, including cirrhosis and liver cancer. The serious consequences of end-stage liver disease and liver cancer occur in 30% of chronic carriers and confront patients and physicians throughout the world. Vaccination is the major form of treatment (prevention) that may eventually eliminate HBV worldwide. This article discusses the currently available treatments as well as evolving treatments for chronic HBV infection.

Detection of hepatitis B virus cccDNA with modified polymerase chain reaction

AIM: To establish a simple and fast hepatitis B virus covalently closed circular DNA(cccDNA) detecting method based on polymerase chain reaction(PCR) with satisfactory sensitivity and specificity.

METHODS: The cccDNA and the relaxed circular DNA (rcDNA) were extracted from HepG2.2.15 cells and supernatant, respectively, and then purified. Two pairs of specific PCR primes were designed to cover the single strand area of rcDNA. And two pairs of non-specific PCR primes were designed to cover the double strand area of rcDNA. Before and after digested by single-strand-specific mung bean nuclease(MBN), cccDNA and rcDNA samples were amplified by specific primes and non-specific primes. Whether the digested cccDNA can be amplified by specific primes, without amplifying the digested rcDNA, was observed. The PCR parameters such as substrate amount and circulation times were changed during amplification. The HBV genome plasmid was used as control; and the HBV samples from patient with hepatitis B was used for practical test.

RESULTS: Different amounts of rcDNA template were amplified by specific and non-specific primes. More than 10⁴ and 10² rcDNA template molecules were amplified by two pairs of specific and non-specific primes, respectively. The specific primes could not discriminate between rcDNA and cccDNA when the template molecules were overabundant. Before and after the digestion by MBN, different amounts of cccDNA were amplified by specific and non-specific primes; and after the digestion, rcDNA templates were amplified by non-specific primes, but not by specific primes. With this strategy, we found the virus samples from the serum of the patient with chronic hepatitis B contained mainly rcDNA and a small quantity of cccDNA, while the samples from hepatocytes contained mainly cccDNA.

CONCLUSION: The combination of MBN selective digestion and specific PCR amplification of the cccDNA is a simple, fast, sensitive and specific method for the detection of HBV cccDNA.

Virological and biochemical relapse after discontinuation of lamivudine monotherapy for chronic hepatitis B in Japan: comparison with breakthrough hepatitis during long-term treatment

OBJECTIVE

Comparison of virological and biochemical relapse in patients with chronic hepatitis B, based on continuation or discontinuation of lamivudine monotherapy.

METHODS

In Japanese genotype C-dominant hepatitis B patients, 25 patients who stopped treatment at normal levels of alanine transferase (ALT) were retrospectively compared with 75 patients who continued treatment. Both groups were matched for age, sex, and observation period after start of treatment. We investigated the relapse rates, and evaluated predictive factors for relapse and efficacy of retreatment of the discontinuous group.

RESULTS

Virological and biochemical relapse occurred significantly earlier in the discontinuous than continuous group, and the peak levels and ratios of peak to pretreatment levels of serum bilirubin and ALT after relapse were not significantly different between the two groups. Multivariate analysis identified three independent factors at discontinuation of treatment associated with early biochemical relapse: HBeAg positivity, presence of liver cirrhosis, detection of basic core promoter mutant. Normalization of ALT levels with retreatment occurred in 62.5% of patients, but 2 HBeAg-positive patients retreated after the emergence of YMDD motif mutant developed severe relapse with hyperbilirubinemia.

CONCLUSION

Our results in Japanese patients with genotype C-dominant hepatitis B suggest that discontinuation of lamivudine monotherapy, and retreatment after the emergence of YMDD mutant should be given attention.

Failure of the lamivudine-resistant rtM204I hepatitis B virus mutants to efficiently support hepatitis delta virus secretion

Hepatitis delta virus (HDV) is encapsidated by the envelope proteins of hepatitis B virus (HBV). The major HBV lamivudine (LMV)-resistant mutations in the polymerase gene within the reverse transcriptase (rt) region at rtM204V or rtM204I are associated with changes in the overlapping envelope gene products, in particular, the gene encoding small envelope protein (s) at sI195M or sW196L/S/Stop. We have demonstrated that the LMV resistance mutations corresponding to sW196L/S inhibited secretion of HDV particles, while changes corresponding to sI195M did not affect secretion. Differential efficiencies of HBsAg proteins expressed by LMV-resistant HBV to support HDV secretion may have consequences for clinical prognosis as coinfected patients are treated with antiviral agents.

Predictive value of HBV cccDNA in PBMC of response to lamivudine therapy in patients with chronic hepatitis B

AIM: To assess the value of hepatitis B virus (HBV) covalently closed circle DNA (cccDNA) in peripheral blood mononuclear cells (PBMC) for the prediction of the sustained response to lamivudine therapy in patients with chronic hepatitis B.

METHODS: Seventeen chronic hepatitis B patients with complete or partial response (serum HBV DNA turned negative, and ALT was normalized with or without HBeAg/anti-HBe seroconversion) were selected. HBV cccDNA in PBMC was detected at the end of lamivudine treatment, and 1 year after treatment.

RESULTS: Nine out of 17 patients were positive for HBV cccDNA in their PBMC at the end of lamivudine treatment. Virological relapse were found during 1-year follow-up in all of these 9 patients; whereas only 1 relapse was observed among the 8 patients without HBV cccDNA.

CONCLUSION: HBV cccDNA in PBMC at the end of treatment is of good predictive value for the sustained response to lamivudine treatment in chronic hepatitis B patients.

End-of-treatment virologic response does not predict relapse after lamivudine treatment for chronic hepatitis B

AIM: Attaining hepatitis B e antigen (HBeAg) seroconversion during lamivudine treatment is associated with fewer relapses in HBeAg-positive patients. In HBeAg-negative patients, predictors for post-treatment relapse remain largely unknown. We therefore studied whether end-of-treatment virologic response correlated with relapse after lamivudine treatment.

METHODS: We prospectively analyzed 12 HBeAg-negative patients and 14 HBeAg-positive patients with chronic hepatitis B, who received at least 9 mo of lamivudine treatment and were followed up for 12 mo post-treatment. Relapse of hepatitis B activity was defined by an elevation of serum ALT level above twice the upper limit of normal as well as reappearance of serum HBV DNA by the branched DNA assay or HBeAg during the follow-up period. The serum viral loads during and at the end of treatment were further determined by a quantitative real-time polymerase chain reaction assay.

RESULTS: Relapse occurred in 6 (50.0%) HBeAg-negative patients within 12 mo post-treatment. Two relapsers had end-of-treatment serum viral load < 1000 copies/mL, the proportion was not significantly different from that in the 6 non-relapsers (33.3% vs 16.7%; P = 1.00). Hepatitis B virus (HBV) DNA levels did not correlate with post-treatment relapse in HBeAg-positive patients either. However, genotype C patients tended to have a lower relapse rate than genotype B patients (14.3% vs 57.9%, P = 0.08).

CONCLUSION: Our results suggest that end-of-treatment virologic response cannot predict post-treatment relapse in patients with HBeAg-negative or -positive chronic hepatitis B. The impact of HBV genotype on the response to lamivudine treatment awaits further studies.

Helper-dependent adenoviral vector-mediated delivery of woodchuck-specific genes for alpha interferon (IFN-alpha) and IFN-gamma: IFN-alpha but not IFN-gamma reduces woodchuck hepatitis virus replication in chronic infection in vivo

Alpha interferon (IFN-alpha) and IFN-gamma are able to suppress hepadnavirus replication. The intrahepatic expression of high levels of IFN may enhance the antiviral activity. We investigated the effects of woodchuck-specific IFN-alpha (wIFN-alpha) and IFN-gamma(wIFN-gamma) on woodchuck hepatitis virus (WHV) replication in vivo by helper-dependent adenoviral (HD-Ad) vector-mediated gene transfer. The expression of biologically active IFNs was demonstrated in vitro after transduction of woodchuck cells with HD-Ad vectors encoding wIFN-alpha (HD-AdwIFN-alpha) or wIFN-gamma (HD-AdwIFN-gamma). The transduction efficacy of the HD-Ad vector in woodchuck liver in vivo was tested with a vector expressing green fluorescence protein (GFP). Immunohistochemical staining of liver samples on day 5 after injection showed expression of GFP in a high percentage of liver cells surrounding the central vein. The transduction of livers of WHV carriers in vivo with HD-AdwIFN-alpha or HD-AdwIFN-gamma induced levels of biologically active IFN, which could be measured in the sera of these animals. Expression of wIFN-alpha in the liver reduced intrahepatic WHV replication and WHV DNA in sera of about 1 log step in two of two woodchucks. Transduction with HD-AdwIFN-gamma, however, reduced WHV replicative intermediates only slightly in two of three animals, which was not accompanied with significant changes in the WHV DNA in sera. We demonstrated for the first time the successful HD-Ad vector-mediated transfer of genes for IFN-alpha and IFN-gamma in vivo and timely limited reduction of WHV replication by wIFN-alpha, but not by wIFN-gamma.

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Phosphorothioate di- and trinucleotides as a novel class of anti-hepatitis B virus agents

Several nucleoside analogs are under clinical development for use against hepatitis B virus (HBV). Lamivudine (3TC), a nucleoside analog, and adefovir dipivoxil (ADV), an acyclonucleotide analog, are clinically approved. However, long-term treatment can induce viral resistance, and following the cessation of therapy, viral rebound is frequently observed. There continues to be a need for new antiviral agents with novel mechanisms of action. A library of more than 600 di- and trinucleotide compounds synthesized by parallel synthesis using a combinatorial strategy was screened for potential inhibitors of HBV replication using the chronically HBV-producing cell line 2.2.15. Through an iterative process of synthesis, lead optimization, and screening, three analogs were identified as potent inhibitors of HBV replication: dinucleotides ORI-7246 (drug concentration at which a 10-fold reduction of HBV DNA was observed [EC(90)], 1.4 microM) and ORI-9020 (EC(90), 1.2 microM) and trinucleotide ORI-7170 (EC(90), 7.2 microM). These analogs inhibited the replication of both strands of HBV DNA. No suppression of HBV protein synthesis or intracellular core particle formation by these analogs was observed. No inhibition of HBV DNA strand elongation by the analogs or their 5'-triphosphate versions was apparent in in vitro polymerase assays. Although the exact mechanism of action is not yet identified, present data are consistent with an inhibition of the HBV reverse transcriptase-directed priming step prior to elongation of the first viral DNA strand. In transient-transfection assays, these analogs inhibited the replication of 3TC-resistant HBV. Synergistic interactions in combination treatments between the analogs and either 3TC or ADV were observed. These compounds represent a novel class of anti-HBV molecules and warrant further investigation as potential therapeutic agents.

Searching for chronic hepatitis B patients in a low prevalence area--role of racial origin

Background

Clinical studies for testing new drugs against hepatitis B ought to be carried out in low prevalence areas despite difficulties on patient recruitment. In such areas, relatives of chronic hepatitis B patients are considered to be at risk of acquiring the hepatitis B virus (HBV). The aim of this study was to evaluate the prevalence of HBV markers (anti-HBc, HBsAg and anti-HBs) in familial members of chronic hepatitis B (CHB) patients according to their origin (Asian or Western) in a low prevalence area, the city of São Paulo, Brazil.

Methods

Twenty three Asian CHB probands and their 313 relatives plus 31 CHB probands of Western origin and their 211 relatives were screened for HBV serological markers; the study was carried out in the outpatient clinic of the University of São Paulo School of Medicine.

Results

Mother to child transmission was greater in the Asian group whereas sexual transmission was more frequent in the Western group (p < 0.0001). Anti-HBc was positive in 90% and 57% of the Asian and Western parents (p = 0.0432) and in 97% and 33% of the Asian and Western brothers (p = 0.0001), respectively. HBsAg was more frequent among the Asian (66%) than the Western (15%) mothers (p = 0.0260) as well as among the Asian (81%) than the Western (19%) brothers (p = 0.0001). We could detect 110 new HBsAg-positive subjects related to the 54 index patients, being the majority (81%) of Asian origin.

Conclusion

In low prevalence area of hepatitis B, family members and household contacts of chronic HBV carriers are at high risk for acquiring hepatitis B.

Viral breakthrough during lamivudine therapy for chronic hepatitis B

The mainstay of therapy for patients with chronic hepatitis B is inhibition of the replicative cycle of hepatitis B virus (HBV) in hepatocytes. Antiviral agents have different potencies. The measurement of HBV DNA in serum can monitor the potency of these therapeutic agents. Viral breakthrough may occur during therapy, which is defined as an abrupt increase in serum HBV DNA levels after a period of persistent suppression. The accuracy of HBV DNA detection depends on the sensitivity of assays. The third-generation quantitative assays have a lower limit of detection in ranges similar to those of quantitative PCR reaching 2 log10 copies/ml. The sensitive assays also give insight into the pathophysiology of chronic hepatitis B. Monotherapy usually suppresses the viral replication inadequately. It only brings about a reduction of serum HBV DNA levels from 8 to 4 log10 copies/ml. In other words, HBV is not completely eliminated. Viral breakthrough occurs with noncompliance to therapy and, also, when drug-resistant mutants emerge. Mutations in the YMDD motif of HBV polymerase lead to resistance to antivirals, such as lamivudine and famciclovir. In clinical practice, the diagnosis and management of viral breakthroughs are problematic and controversial. Due to advances in therapy, more potent agents are available such as adefovir dipivoxil that seldom induce viral breakthroughs for up to 134 weeks of therapy. Potent antiviral agents also lead to the decline of cccDNA in hepatocytes. Combination therapies may further improve efficacy and avoid viral breakthroughs.

Interferon–Lamivudine Combination is No Better than Lamivudine Alone in Anti-Hbe-Positive Chronic Hepatitis B

Background and aims

Results of studies using lamivudine and interferon combination in the treatment of chronic hepatitis B are not consistent or conclusive. This study aimed to evaluate the efficacy of interferon plus lamivudine use versus single lamivudine in anti-HBe-positive chronic hepatitis B.

Methods

Eighty patients were treated with either lamivudine or lamivudine plus simultaneously started interferon. Patients were assigned in groups according to random allocation rule. Lamivudine was given 150 mg/day for 96 weeks in each group; interferon was administered 10 MU three times a week for 24 weeks in the combination therapy group.

Results

Alanine aminotransferase (ALT) normalization was achieved earlier in patients treated with lamivudine alone. At the end of treatment, there was no difference between the groups with respect to HBV DNA negativity, ALT normalization and breakthrough rate. Histological improvement was remarkable in each group, but fibrosis score and necro-inflammatory activity were much lower in lamivudine-treated patients.

Conclusions

Addition of interferon to the lamivudine regimen does not increase the effectiveness of the treatment. Considering the side effects of interferon treatment, this combination seems not to be convenient for anti-HBe-positive chronic hepatitis B.

Clinical course after stopping lamivudine in chronic hepatitis B patients with lamivudine-resistant mutants

BACKGROUND

The efficacy of lamivudine therapy in chronic hepatitis B is well established. However, drug-resistant YMDD mutants emerge with extended therapy. This may result in the resurgence of viral replication, the return of hepatitis and histological deterioration.

AIM

To study the safety of stopping lamivudine when the drug is no longer effective.

METHODS

In the 5-year Asian Lamivudine Study, 34 patients from a single centre were included in this study. They had harboured YMDD mutants for at least 2 years. Lamivudine was discontinued and they were followed up at regular intervals. Clinical symptoms, liver biochemistry and viral serology were monitored.

RESULTS

In a median follow-up of 20 months after stopping lamivudine (range, 7-39 months), 20 of the 34 patients (58.8%) had elevated alanine aminotransferase (ALT), 13 patients (38.2%) had elevated ALT one to five times the upper limit of normal and seven patients (20.6%) had an ALT flare (ALT more than five times the upper limit of normal with detectable hepatitis B virus DNA). There was no liver decompensation. ALT flare could be predicted by ALT over twice the upper limit of normal at the time of stopping lamivudine (P = 0.037).

CONCLUSIONS

It is relatively safe to stop lamivudine after YMDD mutants have emerged. ALT levels greater than or equal to twice the upper limit of normal at the time of stopping lamivudine have a higher risk for ALT flare.

Predicting relapse after cessation of Lamivudine monotherapy for chronic hepatitis B virus infection

There have been reports of relapse after cessation of lamivudine monotherapy for hepatitis B virus (HBV) infection. The aim of this study was to examine factors that predict posttreatment relapse. Comparison 22 patients who experienced relapse with 11 who did not after cessation of therapy showed that predictive factors for nonrelapse were hepatitis B e antigen seroconversion and duration of undetectable HBV DNA load (<0.7 log IU/mL), as determined by HBV real-time detection direct testing. However, 7 of 12 patients with seroconversion experienced relapse after cessation of therapy. Multivariate analysis revealed that the duration of an undetectable HBV DNA load was the only independent predictive factor for nonrelapse (odds ratio, 0.50; 95% confidence interval, 0.27-0.9). More-prolonged lamivudine therapy is required after seroconversion, and persistent duration of an HBV DNA level of <0.7 log IU/mL for >6 months can more accurately aid in the decision of when to stop lamivudine therapy.

Comparison of Antiviral Effect of Lamivudine with Interferon-α2A versus -α2B in Children with Chronic Hepatitis B Infection

Aim

To compare additive efficacy of combination therapy including interferon (IFN)-α2a+lamivudine (3TC) to IFN-α2b+3TC in children with chronic hepatitis B virus (HBV) infection.

Material and methods

Chronic hepatitis B infection was determined by presence of HBsAg, HBeAg and HBV DNA in serum screened at 3 months intervals for at least 1 year, serum alanine transaminase (ALT) levels more than 1.5-times the upper normal limit and chronic hepatitis with histological activity index (HAI) more than 6 by liver biopsy. Sixty-three children with chronic hepatitis B infection were treated randomly with thrice-weekly subcutaneous injections of 5 MU/m2 recombinant IFN-α2a ( n=29) or recombinant IFN-α2b ( n=34) with the same dose, intervals for 6 months. Patients also received 3TC (4 mg/kg/day, max 100 mg/day) orally daily combined with IFN and continued for 12 months. End of therapy response was defined as ALT normalization, HBV DNA clearance and HBe/anti-HBe seroconversion. Breakthrough infection was determined as re-emergence of HBV DNA in serum after its clearance. Response rate, incidence of side effects and breakthrough infection were compared between IFN-α2a+3TC- and IFN-α2b+3TC-treated patients.

Results

Response rate was 44.8% ( n=13) with IFN-α2a+3TC and 47.1% ( n=16) with IFN-α2b+3TC ( P=1.0). No significant difference was found in respect to the DNA clearance ( P=0.32), anti-HBe ( P=1.0), anti-HBs ( P=0.09) seroconversion and response rates ( P=1.0) between the groups. Breakthrough infection was detected in 1 (3.4%) case on IFN-α2a and none of the cases on IFN-α2b ( P=0.46). All of the patients experienced flu-like symptoms, malaise and fatigue; however, side effect interfering with therapy was not encountered.

Conclusion

No significant difference was found in response rates achieved by combination therapies based on IFN-α2a and IFN-α2b. Clinical efficacy of 3TC and two different IFN subtypes was found similar.