Hepatitis B virus epidemiology, disease burden, treatment, and current and emerging prevention and control measures

Reviews for APASL guidelines: immunomodulator therapy of chronic hepatitis B

The primary aim of immunomodulator therapy is to help the natural human immune system to mount a defense against hepatitis B virus. IFN-alpha has been used for the treatment of HBeAg-positive and HBeAg-negative chronic hepatitis B for over two decades and has been shown to be effective in suppressing HBV replication and in inducing serological response leading to long-term clinical benefits. IFN-alpha has been used in patients with well-compensated cirrhosis with comparable or better response to that in non-cirrhotic patients. IFN-alpha therapy in patients with cirrhosis has a similar side effect profile as in those without cirrhosis. However, IFN-alpha is contraindicated in patients with overt or decompensated cirrhosis. Pegylated IFN-alpha has been shown to be effective in treatment of chronic hepatitis B with sustained response rate in about one-third of the treated patients. Peg IFN-alpha treatment in non-responders to lamivudine or adefovir dipivoxil showed similar response rate to that seen in naïve patients. Thymosin alpha(1) is effective in treatment of HBeAg-positive and HBeAg-negative chronic hepatitis B with a significantly increasing virological response over time after therapy.

The long-term effects of lamivudine treatment in patients with HBeAg-negative liver cirrhosis

INTRODUCTION

In hepatitis B virus (HBV)-related liver cirrhosis, patients with HBV replication show a higher mortality rate than those without. We aimed to investigate the long-term effects of lamivudine on HBV DNA suppression, Child-Pugh score, and survival in patients with hepatitis Be antigen (HBeAg)-negative liver cirrhosis.

METHODS

Sixty-eight patients (51 male, 17 female) diagnosed with HBV-positive liver cirrhosis, who were monitored by the hepatology and liver transplantation outpatient clinics of our hospital between June 1999 and May 2007, were included in the study. Lamivudine (100 mg/day) was administered orally. Follow-up visits were scheduled monthly during the first 3 months, and every 3 months thereafter. Complete blood count, haemostasis, biochemistry (aspartate aminotransferase [AST], alanine aminotransferase [ALT], amylase, urea, creatinine, total bilirubin, direct bilirubin, total protein, albumin), and alpha-foetoprotein were recorded every 3 months. HBV DNA levels, abdominal ultrasound and the Child-Pugh score were evaluated every 6 months.

RESULTS

Sixty-eight patients (mean age, 52.05+/-12.6 years) were monitored for 49.51+/-18.51 months. Basal ALT, HBV DNA levels and Child-Pugh scores were 103.9+/-73.9 IU/ml, 4133+/-121,94 IU/ml, and 7.6+/-2.4, respectively. The ALT normalisation was 59.7% during the first year, 68.2% during the second year and 44.4% during the fifth year. There was a significant decrease in Child-Pugh scores in the first 3 follow-up years when compared with the baseline score (P<0.05). During the treatment, HBV DNA positivity and YMDD mutations were determined in 20 of 68 (29.4%) patients at 46+/-17.9 months. Nine patients (13.2%) developed hepatocellular carcinoma at 44.8+/-21.5 months. Thirteen patients (19.1%) died during the treatment due to liver failure or variceal bleeding.

CONCLUSION

Lamivudine is beneficial in patients with HBeAg-negative liver cirrhosis in terms of improvement in liver function and enhancement of survival and quality of life. An HBV DNA suppressive effect and improvement in Child-Pugh score were seen especially in the first years. It is important to be aware of YMDD mutation early, as addition of new antivirals is necessary to overcome unwanted results of the mutation.

Hepatitis B virus infection and immunization status in a new generation of injection drug users in San Francisco

Hepatitis B virus (HBV) infection is common among injection drug users (IDU). Younger IDU, however, may be less susceptible to infection due to the implementation of public health interventions, such as universal immunization programs and syringe exchange programs. To investigate the current epidemiology of HBV infection and control among a new generation of drug users in the United States, we conducted interviews and examined HBV serologic markers in a cross-section of street-recruited IDU under age 30 in San Francisco, CA. Of the 831 persons studied, 21% showed serologic evidence of current or past infection; 22% had isolated antibodies to hepatitis B surface antigen consistent with vaccine-mediated immunity; and 56% had no HBV markers. In multivariate analyses, HBV infection was associated with drug use behaviour in heterosexual males; sexual behaviour in males who have sex with males; and both drug use and sexual behaviour in females. Vaccine-mediated immunity was independently associated with female sex and younger age. In conclusion, HBV transmission persists among young IDU in San Francisco. Few young injectors show evidence of successful immunization and the majority remains susceptible to disease. Until the broad effects of universal vaccination are seen, targeted and innovative approaches to immunizing young IDU in the US are needed to prevent a substantial number of new HBV infections.

Hepatitis B virus transmission pattern and vaccination efficiency in Uzbekistan

A national program of universal vaccination for the prevention of chronic hepatitis B virus (HBV) infection was launched in Uzbekistan since 1998. To evaluate the 6 years' outcome of the program, 567 children were enrolled in the study. Among those enrolled, 333 had immunized with adw2 type based Engerix-B (Glaxo Smith Kline Beechem, Rixensart, Belgium) and 48 with adr type based Hepavax-Gene (Green Cross Vaccine Corporation, Korea). A cohort of 186 children born before the immunization program, was also included in the study. When 45 vaccinated children were compared to age/sex-matched 45 unvaccinated children, the sero-prevalence of HBsAg was 0 versus 11% (P = 0.56), and of anti-HBc was 0% versus 44% (P < 0.0001), respectively. Loss of anti-HBs was observed in 18.4% after 5 years. Among 13 HBsAg carriers found in this study, genotype HBV/D was found in 69%, HBV/A in 23% (all in unvaccinated group) and HBV/C in 8% (in vaccinated group). No significant differences were observed in this study between groups which received different vaccine formulation. Phylogenetic analysis of the HBV isolates obtained from family members of the HBsAg-positive children, revealed evidence suggesting that transmission in the vaccinated group was exclusively perinatal, whereas in the unvaccinated group horizontal transmission pattern predominated. In conclusion, HBV universal vaccination is efficient in Uzbekistan irrespective of the vaccine formulation used, because the horizontal transmission pattern predominates currently in this endemic region.

Comparison of low-dose pegylated interferon versus standard high-dose pegylated interferon in combination with ribavirin in patients with chronic hepatitis C with genotype 3: an Indian experience

BACKGROUND AND AIMS

In chronic hepatitis C virus (HCV) infection with genotype 3, therapy with pegylated interferon (peg-IFN) alfa-2b in a dose of 1.5 mug/kg/week and ribavirin (800-1000 mg/day) is recommended for 24 weeks. Reduced doses of peg-IFN may increase compliance and decrease cost and adverse events. This study aimed to assess the safety and efficacy of two different regimens of peg-IFN alfa-2b, in combination with ribavirin, in genotype 3 patients.

METHODS

A total of 103 liver biopsy-proven chronic HCV patients with genotype 3, having alanine aminotransferase levels >1.2 x ULN and positive HCV-RNA were randomized into two groups: group I (n = 76; age, 43.1 +/- 11.4 years; male/female, 67/9) received peg-IFN 1.0 mug/kg/week + ribavirin 10.6 mg/kg/day, while group II (n = 27; age, 37.3 +/- 11.6 years; male/female, 21/6) received peg-IFN 1.5 microg/kg/week + ribavirin 10.6 mg/kg/day. Patients in both groups were treated for 24 weeks. End of treatment viral response (ETVR) and sustained viral response (SVR) after a 6-month follow-up period were assessed.

RESULTS

In both groups I and II, one patient was lost to follow-up, while one patient in group II withdrew due to side-effects. ETVR was seen in 72/76 (94.7%) of patients in the low dose group and 24/27 (88.9%) of patients in the high dose group (P = 0.375). SVR was seen in 60/76 (78.9%) of patients in the low dose group and 25/27 (92.6%) of patients in the high dose group (P = 0.145). Age (Pearson correlation coefficient = 0.263; P = 0.008) and fibrosis (correlation coefficient, 0.263; P = 0.008) showed a significant correlation with the SVR.

CONCLUSION

In patients with genotype 3, peg-IFN at 1.0 microg/kg/week with ribavirin is as effective as peg-IFN at 1.5 mug/kg/week with ribavirin.

Antiviral therapy with entecavir combined with post-exposure "prime-boost" vaccination eliminates duck hepatitis B virus-infected hepatocytes and prevents the development of persistent infection

Short-term antiviral therapy with the nucleoside analogue entecavir (ETV), given at an early stage of duck hepatitis B virus (DHBV) infection, restricts virus spread and leads to clearance of DHBV-infected hepatocytes in approximately 50% of ETV-treated ducks, whereas widespread and persistent DHBV infection develops in 100% of untreated ducks. To increase the treatment response rate, ETV treatment was combined in the current study with a post-exposure "prime-boost" vaccination protocol. Four groups of 14-day-old ducks were inoculated intravenously with a dose of DHBV previously shown to induce persistent DHBV infection. One hour post-infection (p.i.), ducks were primed with DNA vaccines that expressed DHBV core (DHBc) and surface (pre-S/S and S) antigens (Groups A, B) or the DNA vector alone (Groups C, D). ETV (Groups A, C) or water (Groups B, D) was simultaneously administered by gavage and continued for 14 days. Ducks were boosted 7 days p.i. with recombinant fowlpoxvirus (rFPV) strains also expressing DHBc and pre-S/S antigens (Groups A, B) or the FPV-M3 vector (Groups C, D). DHBV-infected hepatocytes were observed in the liver of all ducks at day 4 p.i. with reduced numbers in the ETV-treated ducks. Ducks treated with ETV plus the control vectors showed restricted spread of DHBV infection during ETV treatment, but in 60% of cases, infection became widespread after ETV was stopped. In contrast, at 14 and 67 days p.i., 100% of ducks treated with ETV and "prime-boost" vaccination had no detectable DHBV-infected hepatocytes and had cleared the DHBV infection. These findings suggest that ETV treatment combined with post-exposure "prime-boost" vaccination induced immune responses that eliminated DHBV-infected hepatocytes and prevented the development of persistent DHBV infection.

Pradefovir: a prodrug that targets adefovir to the liver for the treatment of hepatitis B

Adefovir dipivoxil, a marketed drug for the treatment of hepatitis B, is dosed at submaximally efficacious doses because of renal toxicity. In an effort to improve the therapeutic index of adefovir, 1-aryl-1,3-propanyl prodrugs were synthesized with the rationale that this selectively liver-activated prodrug class would enhance liver levels of the active metabolite adefovir diphosphate (ADV-DP) and/or decrease kidney exposure. The lead prodrug (14, MB06866, pradefovir), identified from a variety of in vitro and in vivo assays, exhibited good oral bioavailability (F = 42%, mesylate salt, rat) and rate of prodrug conversion to ADV-DP. Tissue distribution studies in the rat using radiolabeled materials showed that cyclic 1-aryl-1,3-propanyl prodrugs enhance the delivery of adefovir and its metabolites to the liver, with pradefovir exhibiting a 12-fold improvement in the liver/kidney ratio over adefovir dipivoxil.

Characteristics of treatment naïve chronic hepatitis B in Bangladesh: younger populations are more affected; HBeAg-negatives are more advanced

BACKGROUND/AIM

Bangladesh is a densely populated country with intermediate endemicity for chronic hepatitis B (CHB). The aim of the present study was to evaluate the biochemical, virological and histological character of CHB patients and to examine the relationship between these indices.

MATERIALS AND METHODS

One thousand and twenty-two patients of CHB fulfilled our inclusion criteria. Inclusion criteria were (1) HBsAg positive for at least 6 months, (2) HBeAg-positive or negative and (3) hepatitis B virus (HBV) DNA positive. Patients with detectable antibodies to human immunodeficiency virus (HIV), hepatitis Delta virus (HDV) or hepatitis C virus (HCV), with previous antiviral treatment, overt cirrhosis and hepatocellular carcinoma, were excluded. Of these, 191 patients were randomly selected for liver biopsy and were evaluated for analysis.

RESULTS

In the 191 patients, male to female ratio was 4.6:1; age distribution was 26.5 +/- 8.5 (mean +/- standard deviation) years. One hundred and seventy-eight (93.2%) patients were under 40 years. Sixty-eight (35.6%) patients were HBeAg-negative, had less DNA load, and were significantly older, more fibrotic and cirrhotic (P < 0.001). Correlation was not found between DNA level and histological activity. Histological activity was not correlated with ALT level in HBeAg-positive patients (P < 0.001).

CONCLUSION

CHB affects the younger population in Bangladesh. HBeAg-positive CHB was associated with more fibrosis and cirrhosis. Serum HBV DNA levels do not correlate with the severity of histological lesions in all patients. Evaluation by liver biopsy remains gold standard for taking decision of treatment.

Low knowledge and high infection rates of hepatitis in Vietnamese men in Sydney

Objective: To describe hepatitis B and C knowledge and self-reported infection and risk behaviour in a group of Vietnamese men living in inner-urban Sydney, in order to assist with future program planning. Methods: Data were collected through telephone interviews conducted in Vietnamese using a structured questionnaire from 499 of 761 eligible men contacted, giving a response rate of 66%. The data were weighted to be consistent with the age distribution of Vietnamese men in the area. The findings were compared with a published national telephone study. Results: Low knowledge levels of hepatitis B and C were found when compared with data from a published national telephone study. The factors associated with higher mean knowledge scores for hepatitis B were being highly acculturated (P < 0.001), ever having been tested for HIV (P < 0.001) and knowing someone with HIV (P < 0.0001). For hepatitis C, the factors were being highly acculturated (P < 0.001), ever injecting drugs (P < 0.05) and being vaccinated for hepatitis B (P < 0.001). Knowledge regarding hepatitis B was particularly poor. High rates of self-reported hepatitis B infection were noted. Of the participants, 7.2% were aware that they had ever been infected with hepatitis B, more than 10 times the rate in the national telephone study. Conclusion: Lower levels of hepatitis B knowledge have been identified in a community with higher numbers of people living with chronic hepatitis B. Targeted community-wide awareness-raising campaigns and health care worker education is required to improve knowledge of hepatitis B and rates of screening in the Australian Vietnamese community.

Lamivudine prophylaxis is effective in reducing hepatitis B reactivation and reactivation-related mortality in chemotherapy patients: a meta-analysis

BACKGROUND

Hepatitis B viral (HBV) reactivation in patients undergoing chemotherapy is associated with significant morbidity and mortality. Lamivudine has been suggested to be useful as a prophylaxis for HBV reactivation; however, its impact on overall survival and HBV reactivation-related liver disease survival is unclear.

OBJECTIVE

To determine the effect of lamivudine prophylaxis on the rate of HBV reactivation, overall survival and HBV reactivation-related survival in patients with HBV undergoing chemotherapy.

METHODS

A comprehensive search of MEDLINE, Cochrane Collaboration Database, reference lists and abstracts from national meetings. Statistical analysis was performed using revman.

RESULTS

Eleven studies met the defined inclusion criteria and were included in the analysis. Two-hundred and twenty patients received lamivudine prophylaxis and 400 did not receive prophylaxis. Patients given lamivudine prophylaxis had an 87% decrease in HBV reactivation [risk ratio (RR) 0.13, 95% confidence interval (CI), 0.07-0.24] than patients not given prophylaxis [absolute risk reduction (ARR) -0.46, 95% CI, -0.61 to -0.31]. The number needed to treat to prevent one reactivation was 3. The Lamivudine prophylaxis group was also associated with a 70% reduction in reactivation-related mortality (RR 0.30, 95% CI, 0.1-0.94) compared with controls (ARR -0.03, 95% CI, 0.07-0.00). There was a reduction in treatment delays and premature termination of chemotherapy in the lamivudine prophylaxis arm (RR 0.41, 95% CI, 0.27-0.63; ARR -0.33, 95% CI, -0.33 to -0.15). There was no significant heterogeneity in the comparisons.

CONCLUSION

Lamivudine prophylaxis during chemotherapy is effective in reducing the rate of HBV reactivation, and reactivation-related liver mortality. Patients with lamivudine prophylaxis had less chemotherapy treatment delays and premature termination of their chemotherapy. Few patients need to be treated to prevent reactivation. Patients with HBV undergoing chemotherapy should be started on lamivudine prophylaxis.

Nitazoxanide, tizoxanide and other thiazolides are potent inhibitors of hepatitis B virus and hepatitis C virus replication

Nitazoxanide (NTZ), a thiazolide anti-infective, is active against anaerobic bacteria, protozoa, and a range of viruses in cell culture models, and is currently in phase II clinical development for treating chronic hepatitis C. In this report, we characterize the activities of NTZ and its active metabolite, tizoxanide (TIZ), along with other thiazolides against hepatitis B virus (HBV) and hepatitis C virus (HCV) replication in standard antiviral assays. NTZ and TIZ exhibited potent inhibition of both HBV and HCV replication. NTZ was equally effective at inhibiting replication of lamivudine (LMV) and adefovir dipovoxil (ADV)-resistant HBV mutants and against 2'-C-methyl cytidine (2'CmeC) and telaprevir (VX-950)-resistant HCV mutants. NTZ displayed synergistic interactions with LMV or ADV against HBV, and with recombinant interferon alpha-2b (IFN) or 2'CmeC against HCV. Pre-treatment of HCV replicon-containing cells with NTZ potentiated the effect of subsequent treatment with NTZ plus IFN, but not NTZ plus 2'CmeC. NTZ induced reductions in several HBV proteins (HBsAg, HBeAg, HBcAg) produced by 2.2.15 cells, but did not affect HBV RNA transcription. NTZ, TIZ, and other thiazolides are promising new antiviral agents that may enhance current or future anti-hepatitis therapies.

Symptomatology and health attitudes of chronic hepatitis B patients in the USA

This study was conducted to understand the symptomatology, attitudes, and behaviours of chronic hepatitis B (CHB) patients in the USA. CHB patients enrolled in this study were recruited through multiple methods, including newspaper advertisements. Interviews were conducted in multiple languages, and all participants had a history of CHB infection for at least 6 months. Patients with documented human immunodeficiency virus or hepatitis C virus coinfection were excluded from data analyses, resulting in a total study population of 258 respondents who completed interviews between April and June 2004. The majority of monoinfected patients were male (57%) and non-Asian (92%, including 52% Caucasian, 32% African American and others). Length of diagnosis was 5.8 years for all participants (9.1-year Asian and 5.1-year non-Asian). Ninety-five per cent of CHB patients reported symptoms of differing severity in the 12 months prior to the survey. The most common symptoms included fatigue/loss of energy (90%) and loss of appetite (79%). Non-Asian patients described greater symptomatology, and were more likely than Asians to consider CHB an overriding concern in their daily activities. Patients were treated either currently or previously with interferon (IFN) described greater symptomatology than those treated without IFN. Survey results indicate that CHB patients may have greater symptomatology than recognized. Disease perceptions and treatment attitudes differ between Asian and non-Asian ethnic groups, with the former appearing to be more accepting and less concerned about the disease. Additional research about CHB symptomatology and health attitudes by ethnicity is needed to ensure that individuals with CHB are educated on the potential health risks and the availability of current treatment options.

Role of horizontal transmission in hepatitis B virus spread among household contacts in north India

OBJECTIVES

Familial clustering of HBV provides epidemiological evidence for the different modes of spread of the virus. Though the majority of the studies have addressed the issue of perinatal transmission in India, only a few reports have dealt with other modes of transmission.

METHODS

The study was prospectively designed and data were collected from a total of 265 household contacts of 91 index patients with HBV-related chronic liver disease between January 2006 and July 2007. The prevalences of HBsAg and various antibodies; anti-HBs, anti-HBc and anti-HBe, were estimated in all household contacts using ELISA and VIDAS.

RESULTS

Among the various household contacts, the highest prevalence of HBsAg was seen in the pediatric age group (kids 1-15 years: 37.0%) and especially in siblings (48.3%), with statistical significance (p < 0.001). Hepatitis B virus (HBV) serological markers were found more commonly in contacts of female (68.8%) index patients as compared to males (p > 0.05). The development of anti-HBV antibodies showed an increasing trend with age (p < 0.001), with the highest prevalence in parents.

CONCLUSION

Horizontal transmission plays an important role in contributing to the high prevalence of HBsAg especially in young children. Hence, this age group needs to be targeted for primary prevention and effective vaccine.

Rational design of a multiepitope vaccine encoding T-lymphocyte epitopes for treatment of chronic hepatitis B virus infections

Protein sequences from multiple hepatitis B virus (HBV) isolates were analyzed for the presence of amino acid motifs characteristic of cytotoxic T-lymphocyte (CTL) and helper T-lymphocyte (HTL) epitopes with the goal of identifying conserved epitopes suitable for use in a therapeutic vaccine. Specifically, sequences bearing HLA-A1, -A2, -A3, -A24, -B7, and -DR supertype binding motifs were identified, synthesized as peptides, and tested for binding to soluble HLA. The immunogenicity of peptides that bound with moderate to high affinity subsequently was assessed using HLA transgenic mice (CTL) and HLA cross-reacting H-2(bxd) (BALB/c x C57BL/6J) mice (HTL). Through this process, 30 CTL and 16 HTL epitopes were selected as a set that would be the most useful for vaccine design, based on epitope conservation among HBV sequences and HLA-based predicted population coverage in diverse ethnic groups. A plasmid DNA-based vaccine encoding the epitopes as a single gene product, with each epitope separated by spacer residues to enhance appropriate epitope processing, was designed. Immunogenicity testing in mice demonstrated the induction of multiple CTL and HTL responses. Furthermore, as a complementary approach, mass spectrometry allowed the identification of correctly processed and major histocompatibility complex-presented epitopes from human cells transfected with the DNA plasmid. A heterologous prime-boost immunization with the plasmid DNA and a recombinant MVA gave further enhancement of the immune responses. Thus, a multiepitope therapeutic vaccine candidate capable of stimulating those cellular immune responses thought to be essential for controlling and clearing HBV infection was successfully designed and evaluated in vitro and in HLA transgenic mice.

Cost-effectiveness analysis of entecavir versus lamivudine in the first-line treatment of Australian patients with chronic hepatitis B

BACKGROUND

Chronic hepatitis B (CHB) virus infection is a major global healthcare problem. The recent introduction of entecavir in Australia for the treatment of CHB patients in the naive treatment setting has triggered significant optimism with regards to improved clinical outcomes for CHB patients.

OBJECTIVE

To estimate, from an Australian healthcare perspective, the cost effectiveness of entecavir 0.5 mg/day versus lamivudine 100 mg/day in the treatment of CHB patients naive to nucleos(t)ide therapy.

METHODS

A cost-utility analysis to project the clinical and economic outcomes associated with CHB disease and treatment was conducted by developing two decision-tree models specific to hepatitis B e antigen-positive (HBeAg+ve) and HBeAg-ve CHB patient subsets. This analysis was constructed using the Australian payer perspective of direct costs and outcomes, with indirect medical costs and lost productivity not being included. The study population comprised a hypothetical cohort of 1000 antiviral treatment-naive CHB patients who received either entecavir 0.5 mg/day or lamivudine 100 mg/day at model entry. The population of patients used in this analysis was representative of those patients likely to receive initial antiviral therapy in clinical practice in Australia. The long-term cost effectiveness of entecavir compared with lamivudine in the first-line treatment of CHB patients was expressed as an incremental cost per life-year gained (LYG) or QALY gained.

RESULTS

Results revealed that the availability of entecavir 0.5 mg/day as part of the Australian hepatologist's treatment armamentarium should result in significantly lower future rates of compensated cirrhosis (CC), decompensated cirrhosis (DC), and hepatocellular carcinoma (HCC) events (i.e. 54 fewer cases of CC, seven fewer cases of DC, and 20 fewer cases of HCC over the model's timeframe for HBeAg+ve CHB patients, and 69 fewer cases of CC, eight fewer cases of DC and 25 fewer cases of HCC over the model's timeframe for HBeAg-ve CHB patients). Compared with lamivudine 100 mg/day, entecavir 0.5 mg/day generated an estimated incremental cost per LYG of Australian dollars ($A, year 2006 values) 5046 and an estimated incremental cost per QALY of $A5952 in the HBeAg+ve CHB patient population, an estimated incremental cost per LYG of $A7063 and an estimated incremental cost per QALY of $A8003 in the HBeAg-ve CHB patient population, and an overall estimated incremental cost per LYG of $A5853 and an estimated incremental cost per QALY of $A6772 in the general CHB population.

CONCLUSION

The availability of entecavir in Australian clinical practice should make long-term suppression of hepatitis B virus replication increasingly attainable, resulting in fewer CHB sequelae, at an acceptable financial cost.

Proteomics of viruses

Proteomics is a promising approach for the study of viruses allowing a better understanding of disease processes and the development of new biomarkers for diagnosis and early detection of disease, thus accelerating drug development. Viral proteomics has included the analysis of viral particles to determine all proteins that compose the infectious virus, the examination of cellular proteins associated with a single viral protein in the hopes of determining all the functions of that viral protein, or the determination of cellular proteins induced or altered during a particular disease state. Viral particles of human cytomegalovirus (HCMV) and Kaposi's sarcoma-associated herpesvirus/human herpesvirus 8 (KSHV/HHV-8) have been recently examined. During the herpesviral replicative cycle, different viral particles are formed. For HCMV, this includes mature, infectious virions, noninfectious enveloped particles, and dense bodies. A proteome database of B-lymphoblastoid cell lines (LCLs), before and after transformation, has been developed to identify the cellular mechanisms of virus-induced immortalization. 2DE is used to first separate proteins based on their relative charge (pI) and then based on their molecular weight. Proteomic analysis has provided a unique tool for the identification of diagnostic biomarkers, evaluation of disease progression, and drug development. It is also an important approach for clinical diagnostics.

Population-based study on the seroprevalence of hepatitis A, B, and C virus infection in Amsterdam, 2004

In order to enhance screening and preventive strategies, this study investigated the seroprevalence of hepatitis A, B, and C in the general adult urban population and in subgroups. In 2004, sera from 1,364 adult residents of Amsterdam were tested for viral markers. Sociodemographic characteristics were collected using a standardized questionnaire. For hepatitis A, 57.0% was immune. Of first-generation immigrants from Turkey and Morocco, 100% was immune. Of all Western persons and second-generation non-Western immigrants, approximately half was still susceptible. For hepatitis B, 9.9% had antibodies to hepatitis B core antigen (anti-HBc) and 0.4% had hepatitis B surface antigen. Anti-HBc seroprevalences were highest among first-generation immigrants from Surinam, Morocco, and Turkey, and correlated with age at the time of immigration, and among men with a sexual preference for men. Seroprevalence among second-generation immigrants was comparable to Western persons. The seroprevalence of hepatitis C virus antibodies was 0.6%. In conclusion, a country with overall low endemicity for viral hepatitis can show higher endemicity in urban regions, indicating the need for differentiated regional studies and prevention strategies. More prevention efforts in cities like Amsterdam are warranted, particularly for hepatitis A and B among second-generation immigrants, for hepatitis B among men with a sexual preference for men, and for hepatitis C. Active case finding strategies are needed for both hepatitis B and C.

Highly endemic hepatitis B infection in rural Vietnam

BACKGROUND AND AIM

Hepatitis B is a major public health problem in Vietnam; however, estimates of the prevalence of hepatitis B virus (HBV) and hepatitis delta virus (HDV), and risk factors in rural Vietnam are limited. The aim of this study was to determine HBV and HDV prevalence, and identify risk factors for HBV infection.

METHODS

A cross-sectional seroprevalence study was undertaken in two rural districts in Thai Binh province. The study population was randomly selected using multistage sampling. Demographic and behavioral risk information and serological samples were obtained from 837 participants.

RESULTS

Mean age was 42.3 years +/- 15.8 (range, 16-82 years), and 50.8% were female. Prevalence of anti-HBV core antibody (anti-HBc) and hepatitis B virus surface antigen (HBsAg) was 68.2% and 19.0%, respectively, and hepatitis B e antigen HBeAg was detected in 16.4% of the HBsAg-positive group. Prevalence of HDV was 1.3% in the HBsAg-positive group. Factors associated with HBV infection (anti-HBc or HBsAg positive) were age 60 years or older (OR, 3.82; 95% CI, 1.35-10.80; P = 0.01), residence in Vu Thu district (OR, 3.00; 95% CI, 2.16-4.17; P < 0.0001), hospital admission (OR, 2.34; 95% CI, 1.33-4.13; P = 0.003) and history of acupuncture (OR, 2.01; 95% CI, 1.29-3.13; P = 0.002). Household contact with a person with liver disease (OR, 2.13; 95% CI, 1.29-3.52; P = 0.003), reuse of syringes (OR, 1.81; 95% CI, 1.25-2.62; P = 0.002) and sharing of razors (OR, 1.69; 95% CI, 1.03-2.79; P = 0.04) were independent predictors of HBsAg positivity. Alanine aminotransferase (ALT) level was elevated (>40 IU/L) in 43% of the HBsAg-positive group; proportion elevated was higher in HBeAg-positive (65%) compared with HBeAg-negative (39%) individuals in this group (P = 0.02).

CONCLUSION

Hepatitis B virus infection is highly endemic in rural Vietnam. Poor infection control activities in health-care settings contribute to high HBV prevalence in this region. Universal HBV infant vaccination and improved infection control procedures are required for improved HBV control in Vietnam.

[Current data on the treatment of chronic hepatitis B]

Despite the development of new therapeutic options, treatment of chronic hepatitis B remains a clinical challenge because of the need for long-term treatment in most patients. Treatment with pegylated interferon is the only option that allows a defined duration of treatment. Nonetheless, approximately 70% of the patients treated do not have a prolonged treatment response. A variety of nucleoside analog viral polymerase (reverse transcriptase) inhibitors have been developed (lamivudine, adefovir dipivoxil, entecavir, telbivudine); they can be administered orally and are well tolerated. These antiviral agents effectively induce viral suppression, which is accompanied by an improvement in transaminases and hepatic histology. Nonetheless, the rates of HBe and HBs seroconversion remain low with nucleoside analogs, and the absence of these immunologic events necessitates prolonged antiretroviral treatment. Treatment with nucleoside analogs leads to selection of resistant mutant viruses. They therefore require close clinical and virologic follow-up to enable early screening for resistance and adaptation of treatment before the liver disease worsens. The development of these different treatment options has made possible very significant improvements in the management of patients with chronic hepatitis B, by preventing aggravation of liver disease in most of them.

Persistent occult hepatitis B virus infection: Experimental findings and clinical implications

Hepatitis B virus (HBV) is a highly pathogenic virus that causes chronic liver diseases in millions of people globally. In addition to a symptomatic, serologically evident infection, occult persistent HBV carriage has been identified since nucleic acid amplification assays of enhanced sensitivity became introduced for detection of hepadnaviral genomes and their replicative intermediates. Current evidence indicates that occult HBV infection is a common and long-term consequence of resolution of acute hepatitis B. This form of residual infection is termed as secondary occult infection (SOI). The data from the woodchuck model of HBV infection indicate that exposure to small amounts of hepadnavirus can also cause primary occult infection (POI) where virus genome, but no serological makers of exposure to virus, are detectable, and the liver may not be involved. However, virus replicates at low levels in the lymphatic system in both these forms. We briefly summarize the current understanding of the nature and characteristics of occult hepadnaviral persistence as well as of its documented and expected pathological consequences.

Hepatitis B vaccination

The BMA adds its voice to the call for universal childhood immunisation in the UK

The role of the woodchuck model in the treatment of hepatitis B virus infection

Experimental studies of animals with chronic hepadnavirus infection could provide valuable insight into optimal therapeutic strategies for individuals with chronic HBV infection. In this review, we focus on the contributions of the woodchuck model to our understanding of HBV biology and on its role in the development of antiviral drug. Furthermore, we consider the implications of studies focusing on the natural history of WHV infection for the management of HBV and the capacity of treatment to prevent complications of chronic hepatitis B infection.

Antiviral prophylaxis for chemotherapy-induced reactivation of chronic hepatitis B virus infection

Chronic hepatitis B virus (HBV) carriers are at considerable risk of reactivation of HBV infection when undergoing chemotherapy or immunosuppressive therapy. Complications of HBV reactivation, including asymptomatic elevation of HBV DNA levels, acute hepatitis, acute liver failure, and delays or dose reductions in chemotherapy, are avoidable with appropriate prophylactic oral antiviral therapy. This article reviews evidence for and presents a grade A recommendation supporting primary prophylaxis among HBV carriers with lamivudine. The dose and duration of prophylaxis, risk of lamivudine resistance, and future directions of prophylactic therapy for HBV reactivation during chemotherapy are discussed. Recommendations are suggested based on expert opinion for prophylaxis with the combination of lamivudine plus adefovir or with entecavir as alternative antiviral strategies that substantially reduce or avoid the risk of HBV antiviral drug resistance.

Clearance of hepatitis B e antigen in patients with chronic hepatitis B and genotypes A, B, C, D, and F

BACKGROUND & AIMS

Persistence of hepatitis B e antigen (HBeAg) in chronic hepatitis B has been associated with increased risk for development of cirrhosis and hepatocellular carcinoma. Five hepatitis B virus genotypes were identified in Alaska Native persons; we analyzed clearance of HBeAg by age and genotype.

METHODS

In this prospective cohort study, 1158 Alaska Native persons throughout Alaska were tested serially for HBeAg for a median of 20.5 years and were genotyped. Initial and final HBeAg-positive specimens, time to clearance, age at clearance, and subsequent HBeAg results were analyzed for persons initially HBeAg-positive. Subsequent HBeAg results were analyzed for persons initially negative.

RESULTS

Genotypes A, B, C, D, and F were identified. Genotype C persons initially HBeAg-positive were more likely than those with other genotypes to be positive on initial and final specimens (P < .001 for each) and time to HBeAg clearance was longer (P < .001). Age at which 50% of persons cleared HBeAg was <20 years for those infected with genotypes A, B, D, and F and 47.8 years in genotype C (P < .001). After losing HBeAg, those with genotypes C and F were more likely to revert to the HBeAg-positive state (P < .001).

CONCLUSIONS

Genotype may have a strong effect on mode of transmission and outcome. Genotype C may have been responsible for most perinatal transmission, given that seroconversion from HBeAg occurs decades later than in other genotypes.

The emergence of YMDD mutants precedes biochemical flare by 19 weeks in lamivudine-treated chronic hepatitis B patients: an opportunity for therapy reevaluation

Given the loss of therapeutic efficacy associated with the development of resistance to lamivudine (LMV) and the availability of new alternative treatments for chronic hepatitis B patients, early detection of viral genotypic resistance could allow the clinician to consider therapy modification before viral breakthrough and biochemical relapse occur. To this end, 28 LMV-treated patients (44 +/- 12 years; 24 men), on their first therapy schedule, were monitored monthly at four Brazilian centers for the emergence of drug resistance using the reverse hybridization-based INNO-LiPA HBV DR assay and occasionally sequencing (two cases). Positive viral responses (HBV DNA clearance) after 6, 12, and 18 months of therapy were achieved by 57, 68, and 53% of patients, while biochemical responses (serum alanine aminotransferase normalization) were observed in 82, 82, and 53% of cases. All viral breakthrough cases (N = 8) were related to the emergence of YMDD variants observed in 7, 21, and 35% of patients at 6, 12, and 18 months, respectively. The emergence of these variants was not associated with viral genotype, HBeAg expression status, or pretreatment serum alanine aminotransferase levels. The detection of resistance-associated mutations was observed before the corresponding biochemical flare (41 +/- 14 and 60 +/- 15 weeks) in the same individuals. Then, if highly sensitive LMV drug resistance testing is carried out at frequent and regular intervals, the relatively long period (19 +/- 2 weeks) between the emergence of viral resistance and the onset of biochemical relapse can provide clinicians with ample time to re-evaluate drug therapy.

Therapeutic vaccination of chronic hepatitis B patients with virus suppression by antiviral therapy: a randomized, controlled study of co-administration of HBsAg/AS02 candidate vaccine and lamivudine

Induction of curative immune responses by therapeutic vaccination in chronic viral infections such as chronic hepatitis B (CHB) is expected to be facilitated by reduction of viral load by antiviral treatment. In this open label, controlled, randomized study, 195 patients with HBeAg positive CHB were randomized to receive 12 doses of HBsAg with AS02B adjuvant candidate vaccine plus lamivudine daily for 52 weeks or lamivudine daily alone. The combined administration of vaccine and lamivudine was safe and well tolerated, but did not improve the HBe seroconversion rate (18.8%) when compared to treatment with lamivudine alone (16.1%) (p=0.6824). Despite induction of a vigorous HBsAg-specific lymphoproliferative response, cytokine production and anti-HBs antibodies, therapeutic vaccination with an adjuvanted HBsAg vaccine administered concomitantly with lamivudine did not demonstrate superior clinical efficacy in HBeAg positive CHB patients as compared to lamivudine therapy alone.

Characterization of a new sensitive PCR assay for quantification of viral DNA isolated from patients with hepatitis B virus infections

Sensitive and accurate quantification of hepatitis B virus (HBV) DNA is necessary for monitoring patients with chronic hepatitis receiving antiviral therapy in order to determine treatment response and to adapt therapy in case of inadequate virologic control. The development of quantitative PCR assays has been crucial in meeting these needs. The objective of this study was to compare the performance of a new real-time PCR assay (Abbott RealTime) for HBV DNA with that of three other commercial assays for the detection of HBV DNA. These were the Versant 3.0 branched-chain DNA assay, the Cobas Amplicor HBV Monitor test, and the Cobas AmpliPrep-Cobas TaqMan hepatitis B virus assay (CAP-CTM). HBV DNA was measured in blood samples taken from two cohorts of patients with chronic hepatitis. HBV DNA levels measured with the Abbott RealTime assay were highly correlated with those measured with the other three tests over their respective dynamic ranges (r, 0.88 to 0.96). The sensitivity (detection limit, 10 IU/ml) and dynamic range of the Abbott RealTime assay (10(1) to 10(9) IU/ml) was superior to that of the Versant assay. The RealTime assay recognized both HBV strains belonging to genotypes A to G and those bearing polymerase gene mutations equivalently. In conclusion, this study demonstrates the utility of the Abbott RealTime assay for monitoring HBV DNA levels in patients with chronic hepatitis B. Its sensitivity and wide dynamic range should allow optimal monitoring of antiviral therapy and timely treatment adaptation.

Short-term response to a booster dose of hepatitis B vaccine in anti-HBs negative adolescents who had received primary vaccination 16 years ago

We conducted a revaccination study to investigate the short-term response to booster hepatitis B (HB) vaccination in seronegative adolescents who had received primary infantile HB vaccination. A booster dose of recombinant HB vaccine was administered to 395 adolescents 15-18 years of age whose serum titers of antibody against hepatitis B surface antigen (HBsAg) (anti-HBs) were <10 mIU/mL. Seventy-seven percent of the booster recipients converted to anti-HBs seropositivity (postbooster titers> or =10 mIU/mL). As compared with adolescents who had undetectable prebooster anti-HBs titers (<0.1 mIU/mL), the seropositive rates and geometric mean titers (GMTs) of 2-month and 1-year postbooster were significantly higher for those of prebooster titers of 0.1-0.9 and 1.0-9.9 mIU/mL (all p<0.0001). Postbooster titers declined significantly more rapidly for those with undetectable prebooster anti-HBs titers than for those with prebooster titers of 0.1-0.9 and 1.0-9.9 mIU/mL. Our observations indicate that a booster dose of HB vaccine maybe unable to induce sufficient immunological response in adolescents who had undetectable residual anti-HBs titers.

Passage from India: an outbreak of hepatitis B linked to a patient who acquired infection from health care overseas

OBJECTIVES

To investigate a nosocomial and community outbreak of hepatitis B to establish how the infections might have occurred.

STUDY DESIGN

Descriptive study.

METHODS

Four cases of hepatitis B who had stayed in hospital during their incubation periods, a case in one of their household contacts, and three further cases in the community were all linked to a patient who had been infected during a renal transplant in India. Medical records from cases were reviewed to extract information about risk factors for infection. Working practices were reviewed to determine how nosocomial transmissions might have occurred. 'Look-back' exercises were conducted to identify and follow-up other patients and staff who might also be at-risk of infection. Hepatitis B viral sequences from all cases were examined to determine whether they were related.

RESULTS

Viral DNA sequences from all nine cases were identical. The primary case had an extremely high viral load due to underlying immunosuppression. Three of the nosocomial transmissions occurred whilst the primary and secondary cases shared general medical wards; two whilst the primary case was in standard isolation. No clear routes of infection were identified. The fourth was associated with a failure of infection control in operating theatres.

CONCLUSIONS

Invasive medical procedures in high-prevalence countries carry a clear risk of blood borne viral infections. There is a need for much better awareness of this risk, both among patients who are considering travelling for treatment, and the health professionals who will be caring for them on their return. Infections may be preventable through hepatitis B vaccination. Patients admitted to hospital following invasive medical procedures in high-prevalence countries should be nursed with stringent infection control measures until blood borne viral infections can be excluded. However, patients with hepatitis B who are highly infectious may transmit the virus despite high standards of infection control.

Clevudine is highly efficacious in hepatitis B e antigen-negative chronic hepatitis B with durable off-therapy viral suppression

Clevudine is a pyrimidine analog with potent and sustained antiviral activity against HBV. In the present study, we evaluated the safety and efficacy of clevudine 30 mg daily for 24 weeks and assessed the durability of antiviral response for 24 weeks after cessation of dosing in hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (e-CHB). We randomized a total of 86 patients (3:1) to receive clevudine 30 mg (n = 63) or placebo (n = 23) daily for 24 weeks. We followed patients for an additional 24 weeks after withdrawal of treatment. The median changes in HBV DNA from baseline were -4.25 and -0.48 log(10) copies/mL at week 24 in the clevudine and placebo groups, respectively (P < 0.0001). Viral suppression in the clevudine group was sustained after withdrawal of therapy, with 3.11 log(10) reduction at week 48. At week 24 and week 48, 92.1% and 16.4% of patients in the clevudine group had undetectable serum HBV DNA levels by Amplicor PCR assay (<300 copies/mL). The proportion of patients who achieved ALT normalization was 74.6% and 33.3% in the clevudine and placebo groups at week 24, respectively (P = 0.0006). ALT normalization in the clevudine group was well-maintained during the post-treatment follow-up period. The incidence of adverse events was similar in the 2 groups. No resistance to clevudine was detected during treatment.

CONCLUSION

A 24-week clevudine therapy was well-tolerated and showed potent and sustained antiviral effect without evidence of viral resistance in e-CHB patients. However, treatment for longer than 24 weeks would be needed to achieve durable remission.

HFE gene in primary and secondary hepatic iron overload

Distinct from hereditary haemochromatosis, hepatic iron overload is a common finding in several chronic liver diseases. Many studies have investigated the prevalence, distribution and possible contributory role of excess hepatic iron in non-haemochromatotic chronic liver diseases. Indeed, some authors have proposed iron removal in liver diseases other than hereditary haemochromatosis. However, the pathogenesis of secondary iron overload remains unclear. The High Fe (HFE) gene has been implicated, but the reported data are controversial. In this article, we summarise current concepts regarding the cellular role of the HFE protein in iron homeostasis. We review the current status of the literature regarding the prevalence, hepatic distribution and possible therapeutic implications of iron overload in chronic hepatitis C, hepatitis B, alcoholic and non-alcoholic fatty liver diseases and porphyria cutanea tarda. We discuss the evidence regarding the role of HFE gene mutations in these liver diseases. Finally, we summarize the common and specific features of iron overload in liver diseases other than haemochromatosis.

Adjuvant effect of CIA07, a combination ofEscherichia coliDNA fragments and modified lipopolysaccharides, on the immune response to hepatitis B virus surface antigen

CIA07 is an immunostimulatory agent composed of bacterial DNA fragments and modified lipopolysaccharide, which has antitumor activity against bladder cancer in mice. In this study, the adjuvant activity of CIA07 was evaluated using hepatitis B virus surface antigen (HBsAg) as the immunogen. Mice were immunized intramuscularly three times at 1-week intervals with HBsAg alone or in combination with alum, bacterial DNA fragments, modified lipopolysaccharide, CIA07 or CpG1826, and immune responses were assessed. At 1 week after the final injection, the HBsAg-specific total serum IgG antibody titer in CIA07-treated mice was 14 times higher than that in animals administered antigen alone, six times higher than in mice given alum or bacterial DNA fragments and twice as high as those treated with modified lipopolysaccharide or CpG1826, and remained maximal until 8 weeks postimmunization. Animals receiving antigen alone or plus alum displayed barely detectable HBsAg-specific serum IgG2a antibody responses. However, coadministration of CIA07 with antigen led to markedly enhanced serum IgG2a antibody titer and IFN-gamma(+) production in splenocytes, indicating that CIA07 effectively induces Th1-type immune responses. In addition, the number of HBsAg-specific CD8(+) T cells in peripheral blood mononuclear cells was elevated in CIA07-treated mice. These data clearly demonstrate that CIA07 is able to induce both cellular and humoral immune responses to HBsAg, and confirm its potential as an adjuvant in therapeutic vaccines for hepatitis B virus infections.

Viral quasi-species evolution during hepatitis Be antigen seroconversion

BACKGROUND & AIMS

Although viral quasi-species evolution may be related to pathogenesis of disease, little is known about this in hepatitis B virus (HBV); consequently, we aimed to evaluate the evolution of HBV quasi-species in patients with well-characterized clinical phenotypes of chronic hepatitis B.

METHODS

Four cohorts of well-defined clinical phenotypes of chronic hepatitis B, hepatitis Be antigen (HBeAg) seroconverters (spontaneous seroconverters and interferon-induced seroconverters) and nonseroconverters (controls and interferon nonresponders) were followed during 60 months on average. Serum from 4 to 5 time points was used for nested polymerase chain reaction, cloning, and sequencing of the precore/core gene (20 clones/sample). Only patients with genotype B were used. Sequences were aligned using Clustal X, then serial-sample unweighted pair grouping method with arithmetic means phylogenetic trees were constructed using Pebble 1.0 after which maximum likelihood estimates of pairwise distances under a GTR + I + G model was assessed. Viral diversity and substitution rates were then estimated.

RESULTS

Analysis of 3386 sequences showed that HBeAg seroconverters had 2.4-fold higher preseroconversion viral sequence diversity (P = .0183), and 10-fold higher substitution rate (P < .0001) than did nonseroconverters, who had persistently low viral diversity (3.6 x 10(-3) substitutions/site) and substitution rate (2.2 x 10(-5) substitutions x site(-1) x month(-1)). After seroconversion, there was a striking increase in viral diversity. Most seroconverters had viral variants that showed evidence of positive selection, which was seen mainly after seroconversion.

CONCLUSIONS

The high viral diversity before a reduction in HBV DNA and before HBeAg seroconversion could either be related to occurrence of stochastic mutations that lead to a break in immune tolerance or to increased immune reactivity that drives escape mutations.

Hepatitis B vaccine uptake among injecting drug users in England 1998 to 2004: is the prison vaccination programme driving recent improvements?

In 1999, the Department of Health allocated additional funding to Health Authorities in England to expand hepatitis B immunization among injecting drug users (IDUs), with the aim of increasing coverage by 20%. In 2001, a vaccination programme for prison inmates in England was also instigated. Between 1998 and 2004 current IDUs participated in a series of annual unlinked anonymous surveys that recorded vaccine uptake (n = 11 383). The proportion self-reporting vaccine uptake rose significantly from 27% in 1998 to 59% in 2004 [adjusted odds ratio: 3.7 (95% CI 3.2-4.3); increase in uptake of 25% per annum (95% CI 22-27%)]. A second survey, which recruited 852 current IDUs from community settings in 2003/04, found that prisons were the most common source (38%) of vaccine doses, followed by drug services (28%) and general practitioners (17%), with only 14% receiving doses through needle exchanges. These data suggest that the 20% target of improving vaccination coverage has been met, with the prison vaccination programme likely to have made a substantive contribution in recent years. However, prevalence of antibodies to the hepatitis B core antigen was stable (21%) and is currently similar among the vaccinated and unvaccinated. Consideration needs to be given to improving community vaccination provision for IDUs, targeting recent initiates, and determining when surveillance data should indicate reductions in infection so that the effectiveness of the targeted strategy can be assessed.

Emerging drugs for hepatitis B

Chronic hepatitis B remains a treatment challenge despite the availability of new nucleoside analogs. This is due to the persistence of viral infection during therapy, which exposes the patient to the risk of developing antiviral drug resistance. Therefore, new polymerase inhibitors are needed to manage resistance to existing drugs and new trials of combination therapy are required to delay drug resistance. In the future, antiviral agents targeting other steps of the viral life cycle will be needed to achieve antiviral synergy and prevent antiviral drug resistance. Immune modulators are also expected to enhance antiviral response and to achieve sustained response. Discovery of new antiviral drugs and design of new treatment strategies are, therefore, needed to manage this disease, which is still the main cause of cirrhosis and hepatocellular carcinoma worldwide.

Twenty years of selective hepatitis B vaccination: is hepatitis B declining among injecting drug users in England and Wales?

Injection drug use is a common route of infection for the hepatitis B virus (HBV) in the UK. The aim of this study was to establish the prevalence and force of infection for HBV among injecting drug users (IDUs) recruited from multiple community and drug agency settings in England and Wales between 1990 and 2004. Cross-sectional studies of IDUs in and out of contact with drug agencies were conducted throughout the 15-year period. Oral fluid samples were tested for antibodies to the hepatitis B core antigen (anti-HBc). Logistic regression was used to investigate associations between risk factors and anti-HBc positivity and force of infection models were explored. In total, 2527 injectors were recruited from community settings, and 29 386 from drug agencies. Anti-HBc prevalence was 31% (95% CI 30.7-31.8%). It declined in the early 1990s from around 50% in 1992 to 25% in 1999, after which it increased slightly. It was also higher in those who had injected for longer, older IDUs, those recruited in London and North West England, and those reporting having a previous voluntary confidential HIV test. The force of infection models suggested that the incidence of infection increased in 1999-2004 compared with 1993-1998, and was higher in new injectors compared with those injecting for > or =1 year. In conclusion, findings suggest ongoing HBV transmission in recent years despite an overall decline in prevalence in the early and mid-1990s, and highlight the importance of targeting vaccination programmes at new IDUs who have high incidence rates of infection.

Risk and predictors of mortality associated with chronic hepatitis B infection

BACKGROUND & AIMS

The study objective was to determine the risk of all-cause and cause-specific mortality as well as to examine the predictors of mortality in chronic hepatitis B infection.

METHODS

We performed a prospective cohort study of 23,820 persons (age, 30-65 y) recruited between 1991 and 1992 and followed up through 2004 from 7 townships in Taiwan. The main outcomes were all-cause and liver-related mortality rates. Mortality analyses used time-to-events methods, and survival curves were derived by the Kaplan-Meier method. Cox proportional hazard models were used to estimate multivariable-adjusted hazard ratios.

RESULTS

There were 1814 deaths during a mean follow-up period of 12.5 years (282,323.7 person-years of follow-up evaluation). Persons positive for hepatitis B surface antigen (HBsAg) had significantly (P < .01) higher adjusted hazard ratios for all causes of mortality (1.7; 95% confidence interval [CI], 1.5-1.9), liver cancer mortality (22.4; 95% CI, 15.2-32.9), and chronic liver disease and cirrhosis mortality (5.4; 95% CI, 3.5-8.4). When compared with HBsAg-negative persons, hepatitis B virus (HBV)-infected persons with HBV DNA levels less than 10(4) had a high risk of hepatocellular carcinoma mortality (4.4; 95% CI, 2.4-8.2). In HBsAg-positive persons, the mortality rate increased with cohort entry serum HBV DNA level. Liver cancer mortality ranged from 72.8 per 100,000 person-years for subjects with HBV DNA levels less than 300 copies/mL to 815.6 per 100,000 person-years for those with HBV DNA levels of 1 million copies/mL or greater. Chronic liver disease and cirrhosis deaths ranged from 9.1 to 267.4 per 100,000 person-years.

CONCLUSIONS

Chronic HBV infection is associated with significant preventable excess mortality risk. This mortality risk is correlated strongly with the level of viral replication among other factors.

Association of p16INK4A hypermethylation with hepatitis B virus X protein expression in the early stage of HBV-associated hepatocarcinogenesis

The aim of the present study was to explore the relationship between methylation status of the p16(INK4A) promoter and some HBV-related factors, and the role of these factors in p16(INK4A) hypermethylation and hepatocellular carcinoma (HCC) progression. Twenty-three cases of surgically resected HBV-associated HCC and 25 fine-needle aspiration biopsy cases of chronic hepatitis B (CHB) were studied. The methylation status of the p16(INK4A) promoter was determined by methylation-specific polymerase chain reaction (PCR). Two-step immunohistochemical staining showed the expression of viral antigens in situ. Tissue HBV-DNA levels were determined by fluorescence quantitative real-time PCR. PCR and the direct sequencing method were used for mutation analysis. In peritumoral tissues (P = 0.025) and CHB samples (P = 0.029), the expression of hepatitis B virus X protein (HBx) was higher in methylated groups of p16(INK4A) promoter than in unmethylated groups. Other HBV factors including hepatitis B surface antigen and hepatitis B core antigen, tissue HBV-DNA levels and HBV x gene mutations had no relation to the methylation status of p16(INK4A) promoter. The data indicate that p16(INK4A) promoter hypermethylation correlated closely with higher HBx expression in the precancerous lesions, suggesting that HBx may play an important role in the early stage of HBV-associated hepatocarcinogenesis via induction of hypermethylation of p16(INK4A) promoter.

Improving outcomes for patients with chronic hepatitis B

A focused meeting on hepatitis B virus (HBV) infection was held at the United States National Institutes of Health in Washington, DC, in April 2006. This meeting focused on new and historical data and served as a review for basic scientists and clinicians, as well as representatives from the pharmaceutical industry. Understanding HBV disease must include up-to-date information concerning virology, immunology, animal models, natural history, prevalence, and transmission risk, as well as an understanding of the evolving therapies for this life-threatening infection. Serious outcomes such as advanced fibrosis, cirrhosis, liver failure and hepatocellular carcinoma from hepatitis B infection appear to be closely tied to both historical and current serum levels of HBV DNA, and elevated serum levels of liver enzymes. Decreasing risk events and vaccinating susceptible individuals are key steps in managing this global scourge. New oral treatments for patients withchronic hepatitis B infection characterized by more potent antiviral effects, less toxicity, and minimal or no risk of resistance were reviewed and emphasized. Entecavir and pegylated interferons have recently been approved for treatment of chronic hepatitis B. Further expansion of our information about lamivudine and adefovir were highlighted. Several other new anti-HBV agents are also in phase II or III clinical trials or have been submitted for licensing including LdT (telbivudine). The NIH review meeting is summarized in this review and new and emerging areas of information are highlighted.

Induction of anti-HBs in HB vaccine nonresponders in vivo by hepatitis B surface antigen-pulsed blood dendritic cells

BACKGROUND/AIMS

Antigen-pulsed dendritic cells (DCs) are now used for treatment of patients with cancers, however, the efficacy of these DCs has never been evaluated for prophylactic purposes. The aim of this study was (1) to prepare hepatitis B surface antigen (HBsAg)-pulsed human blood DCs, (2) to assess immunogenicity of HBsAg-pulsed DCs in vitro and (3) to evaluate the efficacy of HBsAg-pulsed DCs in hepatitis B (HB) vaccine nonresponders.

METHODS

Human peripheral blood DCs were cultured with HBsAg to prepare HBsAg-pulsed DCs. The expression of immunogenic epitopes of HBsAg on HBsAg-pulsed DCs was assessed in vitro. Finally, HBsAg-pulsed DCs were administered, intradermally to six HB vaccine nonresponders and the levels of antibody to HBsAg (anti-HBs) in the sera were assessed.

RESULTS

HB vaccine nonresponders did not exhibit features of immediate, early or delayed adverse reactions due to administration of HBsAg-pulsed DCs. Anti-HBs were detected in the sera of all HB vaccine nonresponders within 28 days after administration of HBsAg-pulsed DCs.

CONCLUSIONS

This study opens a new field of application of antigen-pulsed DCs for prophylactic purposes when adequate levels of protective antibody cannot be induced by traditional vaccination approaches.

Administration of hepatitis B vaccine in winter as a significant predictor of the poor effectiveness of vaccination in rural Mongolia: evidence from a nationwide survey

BACKGROUND

Universal hepatitis B (HB) immunisation is the most effective means for prevention of hepatitis B virus (HBV) infection worldwide. Maintaining the vaccine cold chain is an essential part of a successful immunisation programme. Our recent nationwide survey in Mongolia has observed significant urban-rural differences in the prevalence of HBV infection among vaccinated cohorts.

OBJECTIVE

To examine whether the administration of HB vaccine in winter contributes to these residential discrepancies on the effectiveness of vaccination.

DESIGN AND SETTING

In 2004, a nationwide serosurvey was carried out covering both urban and rural areas of Mongolia. Sampling was multistage, with random probability from all public schools in the country.

PARTICIPANTS

A random sample of 1145 children (51.7% boys; aged 7-12 years), representative of Mongolian elementary school children.

RESULTS

Multivariate logistic regression analysis identified that total (past and current) HBV infection (OR 2.31, 95% CI 1.20 to 4.42; p = 0.012) was independently associated with the administration of all HB vaccines in winter. An increased OR for current HBV infection was also observed (OR 2.58, 95% CI 0.87 to 7.68; p = 0.089), but without significance. Interestingly, after stratifying by residence, the association between winter vaccination and total HBV infection was evident for rural (p = 0.008) but not for urban areas (p = 0.294). The frequency of vaccine-induced immunity was significantly (p = 0.007) lower for those who received HB vaccine at birth during winter in rural areas.

CONCLUSION

Administration of HB vaccine during winter is an important predictor of the low effectiveness of vaccination in rural Mongolia. To improve the effectiveness of HB vaccination in remote areas, cold chain control should be addressed with particular attention to the winter season.

Should hepatitis B vaccination be introduced into childhood immunisation programmes in northern Europe?

Infection with hepatitis B causes between 500,000 and 1.2 million deaths per year worldwide, and is the leading cause of liver cancer. Over 12 years ago, WHO recommended that universal childhood hepatitis B vaccination be implemented globally. Despite this, Denmark, Finland, Iceland, Ireland, the Netherlands, Norway, Sweden, and the UK have yet to implement such a policy and instead currently adopt an "at-risk" strategy. Although all eight countries are classed as having low endemicity, factors such as increased travel and integration of immigrant communities are increasing the number of at-risk individuals in these countries. Considering the difficulty in identifying all at-risk individuals, and the lack of effectiveness of at-risk vaccination on reducing the overall incidence of hepatitis B, we recommend that these countries reassess their hepatitis B prevention strategies. Universal vaccination against hepatitis B is the only way to eliminate the major public-health impact of this disease.

Improving outcomes for patients with chronic hepatitis B

The ultimate goal in managing patients with chronic hepatitis B (CHB) is to improve long-term outcomes by decreasing deaths and liver transplantation procedures due to hepatitis B virus (HBV)-related cirrhosis and hepatocellular carcinoma. Active intervention and vaccination of individuals susceptible to HBV infection are key steps to decrease the risk of this global public health problem. Large studies have demonstrated that long-term outcomes of CHB are tied to serum levels of HBV DNA. New oral treatments, characterized by potent antiviral effects, good tolerability, improved histology, stable seroconversion, and minimal resistance, are available. Long-term data with oral medications have shown decreased rates of liver cancer development, liver disease reversal, and progression to liver failure. Pegylated interferon trials have demonstrated modest rates of hepatitis B e antigen seroconversion and improved histology after treatment. This paper describes ways to improve outcomes of CHB using vaccines, interferon, lamivudine, adefovir, and newer agents.

Involvement of host cellular multivesicular body functions in hepatitis B virus budding

Hepatitis B virus (HBV) is a major human pathogen that chronically infects approximately 350 million people, causing liver disease and liver cancer. HBV virions bud into an endoplasmic reticulum (ER)-associated intracellular compartment, but the mechanisms of HBV assembly, budding, and release remain poorly understood. Budding of retroviruses and some other enveloped RNA viruses from plasma membranes requires host functions involved in protein sorting into late endosomal multivesicular bodies (MVBs). To determine whether budding of DNA-containing HBV virions at intracellular membranes also involves MVB functions, we used immunofluorescence to show that, in human hepatoma cells, HBV envelope protein colocalizes with MVB proteins AIP1/ALIX and VPS4B. We also found that a dominant negative (DN) AIP1 mutant inhibited production and/or release of enveloped virions without significant effects on intracellular nucleocapsid formation, whereas DN VPS4B inhibited both nucleocapsid production and budding. By contrast, DN AIP1 and VPS4 had no effect on the efficiency of release of enveloped, nucleocapsid-lacking HBV subviral particles, which are produced in vast excess over virions, and dramatically increased the release of unenveloped, naked nucleocapsids by an apparently nonlytic route. Thus, host MVB functions are required for efficient budding and release of enveloped HBV virions and may be a valuable target for HBV control. Moreover, HBV enveloped virions, enveloped subviral particles, and unenveloped nucleocapsids are all released by distinct pathways with separate host factor requirements.