Hepatitis B genotypes and the response to interferon therapy

Is there any value to hepatitis B virus genotype analysis?

Hepatitis B may cause a varying spectrum of diseases ranging from an asymptomatic or mild anicteric acute illness, to severe or fulminant hepatitis. Similarly, the outcome of chronic hepatitis B is variable. Viral factors associated with outcome of chronic hepatitis B virus (HBV) infection include hepatitis B e antigen status, HBV DNA, genotype, and HBV variants. HBV genotypes and subgenotypes have been associated with differences in clinical and virological characteristics, indicating that they may play a role in the virus-host relationship. A total of ten hepatitis B virus genotypes have been defined with a distinct geographical distribution. Hitherto, genotypes A, B, C and D have been studied most extensively. The HBV genotype appears to influence not only the natural history of HBV related liver disease but also the response to HBV treatment. HBV genotypes are also linked with both core promoter and BCP mutations. Progression to chronic infection appears to occur more frequently following acute infection with genotypes A and D than with the other studied genotypes. Genotypes A and B appear to have higher rates of spontaneous HBeAg seroconversion. More advanced liver disease and progression to HCC is more often seen in chronic infection with genotypes C and D in contrast to genotypes A and B. More specifically, genotypes A1, C, B2-B5 and H appear to be associated with more serious complications than genotypes A2, B1 and B6. These observations suggest important pathogenic differences between HBV genotypes. Genotypes A and B have higher response rates to interferon based therapy than genotypes C and D. Knowledge of HBV genotype enables clinicians to identify those patients at increased risk of disease progression whilst aiding the selection of appropriate antiviral therapy. Genotyping and monoclonal subtyping can provide useful information for epidemiological studies. In conclusion, genotyping of chronic HBV infections can help practicing physicians identify those at risk of disease progression and determine optimal anti-viral therapy.

Etiology and Viral Genotype in Patients with End-Stage Liver Diseases admitted to a Hepatology Unit in Colombia

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are the principal risk factor associated to end-stage liver diseases in the world. A study was carried out on end-stage liver disease cases admitted to an important hepatology unit in Medellin, the second largest city in Colombia. From 131 patients recruited in this prospective study, 71% of cases were diagnosed as cirrhosis, 12.2% as HCC, and 16.8% as cirrhosis and HCC. Regarding the risk factors of these patients, alcohol consumption was the most frequent (37.4%), followed by viral etiology (17.6%). Blood and/or hepatic tissue samples from patients with serological markers for HCV or HBV infection were characterized; on the basis of the phylogenetic analysis of HCV 5' UTR and HBV S gene, isolates belonged to HCV/1 and HBV/F3, respectively. These results confirm the presence of strains associated with poor clinical outcome, in patients with liver disease in Colombia; additionally, HBV basal core promoter double mutant was identified in HCC cases. Here we show the first study of cirrhosis and/or HCC in Colombian and HBV and HCV molecular characterization of these patients. Viral aetiology was not the main risk factor in this cohort but alcohol consumption.

Molecular epidemiology of hepatitis B virus

Although safe and effective vaccines for hepatitis B virus (HBV) have been available for nearly three decades, this virus kills at least 600,000 people annually worldwide and remains the leading global cause of chronic hepatitis, cirrhosis, and hepatocellular carcinoma. Because the HBV reverse transcriptase lacks a proofreading function, many HBV genotypes, subgenotypes, mutants, and recombinants exist. At least 10 HBV genotypes (HBV-A through J) with distinct geographic distributions have been identified; by definition, their complete genomic sequences diverge by more than 8%. HBV genotype is increasingly becoming recognized as an important factor in the progression and clinical outcome of HBV-induced disease. Infections by HBV-C or -D are significantly more likely to lead to cirrhosis and hepatocellular carcinoma than are infections by HBV-A or -B. Additionally, the hepatitis B e antigen seroconversion response to standard or pegylated interferon is more favorable in patients with HBV-A or -B than in those with HBV-C or -D. However, therapeutic responses to nucleos(t)ide analogues are generally comparable among HBV genotypes. In conclusion, genotyping of HBV is useful in identifying chronic hepatitis B patients who are at increased risk of disease progression, thereby enabling physicians to optimize antiviral therapy for these patients.

Fighting against viral hepatitis: lessons from Taiwan

Viral hepatitis and its sequelae are important health problems worldwide, including Taiwan. For the last 40 years, Taiwan's scientists and health care providers have worked hard to control these sequelae, and the results have been excellent. The author, Ding-Shinn Chen, had a key role in planning and establishing the control program in Taiwan, and participated in the endeavors from the very beginning. In this perspective, he describes how he became interested in research as a medical student, his encounters with hepatitis B and C, how he and his colleagues started early detection of hepatocellular carcinoma (HCC), how he helped Taiwan's government create and implement the Viral Hepatitis Control Program, and how the effectiveness of the program in the decrease of hepatitis B carriage and HCC was monitored. He also discusses how he pioneered the use of interferon-α plus ribavirin to treat chronic hepatitis C. Hepatitis B viral load as a risk factor for HCC and cirrhosis in hepatitis B surface antigen carriers is reviewed briefly, as is the prevention of sequelae by antiviral therapies. Finally, Dr. Chen discusses unresolved issues that must be addressed and predicts the changes of the patterns of liver disease in Taiwan beyond the mid-21st century, which is in part affected by the fight against viral hepatitis that was initiated in the early 1980s.

CONCLUSION

Dr. Chen's perspective illustrates Taiwan's fight against viral hepatitis over the last 40 years. This experience can be shared by other countries in which the disease is equally prevalent.

Treatment of Hepatitis B e Antigen-negative Patients

Hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (CHB) occurs at the late phase in hepatitis B virus (HBV) infection's natural history. The disease is characterized by progressive liver damage due to variants with mutations in the precore/core promoter region that reduce or abolish HBeAg expression. Chronic HBeAg-negative disease's prognosis is poor, with only rare incidences of spontaneous remission. Recent studies in Europe, Asia, and the United States all have reported an increased prevalence of HBeAg-negative and a decreased prevalence of HBeAg-positive chronic hepatitis; this may be related to increased awareness, decrease in new HBV infections, and aging of existing carriers. The end point of therapy for HBeAg-negative CHB patients is difficult to assess. In most studies, HBV DNA suppression and normalization of serum alanine aminotransaminase levels have been used to indicate therapeutic response. Six drugs currently are licensed for the treatment of CHB infection. These are the immunomodulatory agents (conventional interferon-alpha-2b and pegylated interferon-alpha-2a) and the nucleoside/nucleotide analogues (lamivudine, adefovir dipivoxil, entecavir, and telbivudine). Sustained treatment response rates generally are poor due to the high probability of relapse, particularly following nucleoside/nucleotide analogue therapy. As not all patients can tolerate or will respond to interferon-based therapy, maintenance therapy with nucleoside/nucleotide therapy is the alternative. However, this latter approach can lead to development of viral resistance and long-term safety concerns.

Ethnic differences in viral dominance patterns in patients with hepatitis B virus and hepatitis C virus dual infection

Studies of hepatitis B virus (HBV)/hepatitis C virus (HCV) dual infection are limited. Most are small, conducted outside the United States, and compare dual infection with HCV monoinfection. The goal of this study was to characterize HBV/HCV dual infection in a large multiethnic, matched, case-control study of dual-infected and HBV-monoinfected patients at two United States centers. Using an International Classification of Disease Version 9 electronic query and chart review, we identified 115 HBV/HCV dual-infected patients with serial HBV DNA, HCV RNA, and alanine aminotransferase (ALT) levels. As a control, 115 HBV-monoinfected patients were chosen randomly and matched with cases by age ±10 years, sex, Asian versus non-Asian ethnicity, and study site. Both groups had similar sex, ethnic, and age distributions (68% male, 83% Asian, age 52 ± 14 years). The median follow-up times were 33 and 38 months for the dual-infected and monoinfected groups, respectively. More monoinfected patients received HBV antiviral therapy than dual-infected patients (43% versus 24%; P = 0.002). No significant difference was detected between the proportion of monoinfected versus dual-infected patients with ALT above 40 U/L at presentation or during follow-up. Dual infection patients exhibited very little HBV/HCV codominance at baseline and throughout follow-up: patients had either HBV viremia with low or absent HCV RNA or detectable HCV RNA with low or absent HBV DNA. Asian ethnicity was predictive of HBV dominance after adjusting for sex, age, and baseline ALT elevation (odds ratio 7.35; P = 0.01).

CONCLUSION

HBV/HCV dual-infected and HBV-monoinfected patients had similar clinical characteristics. Asian ethnicity is a major independent predictor of HBV-dominant disease, and HCV dominance with undetectable HBV DNA is more common in non-Asian individuals. Larger studies are needed to further characterize the natural history of HBV/HCV dual infection in Asian and non-Asian individuals.

Hepatitis B virus genotype B results in better immediate, late and sustained responses to peginterferon-alfa in hepatitis-B-e-antigen-positive patients

BACKGROUND AND AIMS

This study investigated outcome predictors in hepatitis-B-e-antigen (HBeAg)-positive chronic hepatitis B patients treated with peginterferon alfa-2a.

METHODS

A total of 88 HBeAg-positive patients receiving peginterferon alfa-2a for 6 months and followed up for at least 24 weeks were prospectively analyzed. Precore and core promoter genes of hepatitis B virus (HBV) were sequenced from the serial serum samples of 88 patients.

RESULTS

After 24 weeks of follow up, 38.6% and 28.4% of patients achieved HBeAg clearance and combined response, respectively. Multivariate analysis disclosed that pretreatment HBeAg sample to cut-off (S/Co) ratio ≤ 200, alanine aminotransferase > 200 IU/mL, HBV genotype B and T1846 were independent factors for HBeAg clearance, and HBeAg S/Co ratio ≤ 200 and HBV genotype B were major determinants for combined response. HBeAg S/Co ratio ≤ 10 at week 12 of therapy was the useful factor for treatment response and had a greater power (P = 0.012) to predict HBeAg clearance than HBV DNA. Patients with HBeAg clearance had a higher frequency of A1896 mutation at baseline and during therapy than those without HBeAg clearance, and the frequency of A1896 decreased during treatment. During follow up, delayed HBeAg seroconversion and reactivation of HBV after HBeAg clearance were observed in eight non-responders and 20 patients with HBeAg clearance, respectively. HBV genotype B was a significant factor to predict both responses.

CONCLUSIONS

Pretreatment HBeAg S/Co ratio ≤ 200 and HBV genotype B were major determinants for treatment response to peginterferon. Genotype-B-infected patients had higher probability of delayed HBeAg clearance and sustained response. Rapid decrease of HBeAg titer was useful on treatment predictor.

Recent advances in the research of hepatitis B virus-related hepatocellular carcinoma: epidemiologic and molecular biological aspects

Hepatocellular carcinoma (HCC) is one of the commonest cancers worldwide, and more than half of HCC patients are attributable to persistent hepatitis B virus (HBV) infections. The best and cheapest way to prevent HBV-related HCC is the implementation of universal hepatitis B vaccination program, by which the incidence rates of childhood HCC have been reduced in several countries, including Taiwan. However, there are still hundreds of millions of HBV carriers in the world that remain a global health challenge. In the past decade, several hepatitis B viral factors such as serum HBV DNA level, genotype, and naturally occurring mutants have already been identified to influence liver disease progression and HCC development in HBV carriers. Several easy-to-use scoring systems based on clinical and viral characteristics are developed to predict HCC risk in HBV carriers and may facilitate the communication between practicing physicians and patients in clinical practice. In addition, the role of nonviral factors in HBV-related HCC has also been increasingly recognized. On the basis of these emerging data, it is recommended that HBV carriers should be screened and monitored to identify those who have a higher risk of liver disease progression and require antiviral treatments. Regarding the molecular carcinogenesis of HCC development, despite some progress in the research of cell biology of HCC in the past decade, aberrant pathways involved in maintaining HCC phenotypes have not been completely elucidated yet. In the future, through comprehensive and integrated approaches to analyze the genomes of human HCC, novel target genes or pathways critically involved in hepatocarcinogenesis may hopefully be identified.

Hepatitis B virus genotypes

Hepatitis B virus (HBV) is a member of the hepadnavirus family and can lead to severe liver disease. HBV has a very high genetic variability. Currently, eight genotypes of HBV have been recognized, and most genotypes are now divided into subgenotypes with distinct virological and epidemiological properties. In addition, recombination among HBV genotypes increases the variability of HBV. This review summarizes current knowledge of the epidemiology of genetic variability in hepadnaviruses and, due to rapid progress in the field, updates several recent reviews on HBV genotypes and subgenotypes.

An overview of treatment response rates to various anti-viral drugs in Pakistani hepatitis B virus infected patients

Hepatitis B virus (HBV) is one of the leading health problem with up to 350 million affected people worldwide including 4.5 million only in Pakistan. It has mortality rate of 0.5 to 1.2 million per year worldwide. Pakistan lies in the endemic region with 3-5% HBV carrier rate in the country. The present article reviews the literature on the treatment response of HBV prevalent in Pakistani population. The average treatment response of Lamivudine and interferon-α is 25.81% and 47.95%, respectively. Peg-Interferon was shown to be not effective against the HBV/HCV (hepatitis C virus)/HDV (hepatitis Delta virus) co-infection. The present study reveals that interferon-α is the most effective therapy available for HBV infection prevalent in Pakistani population. Genotype C & D are the most common HBV genotypes in Pakistan and are associated with increased severity and less response to interferon therapy. This poses a great challenge for physicians and researchers and further studies are needed to describe the outcome of the current therapies recommended against HBV infection in Pakistani population.

Management and treatment of hepatitis B virus in patients with HIV infection: A practical guide for health care professionals

The management and treatment of HIV and hepatitis B virus (HBV)-coinfected patients present specific challenges for clinicians. The morbidity and mortality related to these concomitant infections are growing concerns, while the use of antiviral drugs effective against both viruses complicates therapeutic decision making. The present document provides guidelines for physicians regarding care and treatment of patients coinfected with HIV and HBV. Primary prevention of HBV in HIV-positive patients is achieved through appropriate vaccination schedules. Follow-up before treatment of HBV may include liver biopsy, screening for hepatocellular carcinoma and testing for esophageal varicies in cases of cirrhosis. In HBV-infected patients requiring treatment, recommendations regarding initiation, duration and choice of first-line drugs are made. Finally, in the case of resistance, appropriate alternative therapies are necessary.

Management of hepatitis B: Consensus of the Japan Society of Hepatology 2009

Recently, much progress has been made in the field of hepatitis B, such as natural history of the disease in relation to the amount of hepatitis B virus (HBV) DNA, genotypes of HBV influencing the natural course and treatment effects, mutations of HBV influencing the severity of the disease and development of hepatocellular carcinoma, and antiviral treatment such as nucleos(t)ide analogues and pegylated interferon. To make the consensus for the diagnosis, management and treatment of hepatitis B, a meeting was held during 45th annual meeting of Japan Society of Hepatology (JSH) in June 2009. In the meeting, recommendations and informative statements were discussed on the following subjects: (i) natural history of HBV infection; (ii) clinical implication of HBV genotypes; (iii) HBV mutations and their potential impact on pathogenesis of HBV infection; (iv) indications for antiviral treatment of chronic hepatitis B; (v) nucleos(t)ide analogues for chronic hepatitis B; and (vi) interferon therapy for chronic hepatitis B. The presenters reviewed the data on these subjects and proposed the consensus statements and recommendations. These statements were discussed among the organizers and presenters, and were approved by the participants of the meeting. In the current report, the relevant data were reviewed and the 12 consensus statements and nine recommendations on chronic hepatitis B were described.

The clinical implications of hepatitis B virus genotype: Recent advances

Outcomes of chronic hepatitis B virus (HBV) infection are heterogeneous. Estimates of annual incidence of cirrhosis and hepatocellular carcinoma (HCC) are 2-10% and 1-3%, respectively. Several viral factors, including HBV genotype, viral load and specific viral mutations, have been associated with disease progression. Among these, HBV genotype is not only predictive of clinical outcomes but has also been associated with response to interferon treatment. Currently, at least 10 HBV genotypes and several subtypes have been identified; they have distinct geographic distribution. Acute infection with genotypes A and D results in higher rates of chronicity than genotypes B and C. Compared to genotype A and B cases, patients with genotypes C and D have lower rates of spontaneous hepatitis B e antigen (HBeAg) seroconversion; when this occurs, it tends to be delayed. HBV genotype C has a higher frequency of basal core promoter (BCP) A1762T/G1764A mutation, pre-S deletion and is associated with higher viral load than genotype B. Similarly, genotype D has a higher prevalence of BCP A1762T/G1764A mutation than genotype A. These observations suggest important pathogenic differences between HBV genotypes. These may contribute to more severe liver disease, including cirrhosis and HCC with genotypes C and D HBV infection. In addition, genotype A and B patients have better responses to interferon-based therapy than genotypes C and D, but there are few consistent differences for direct HBV antivirals. In conclusion, genotyping of chronic HBV infections can help practicing physicians identify those at risk of disease progression and determine optimal anti-viral therapy.

Characterization of hepatitis virus B isolated from a multi-drug refractory patient

Prolonged treatment of chronic hepatitis B (CHB) with nucleoside analogues (NAs) almost invariably engenders viral resistance, and sequential NAs monotherapy can promote multi-drug resistance. This study aimed to investigate the molecular characteristics and the mutation profile of multi-drug resistant hepatitis B virus (HBV). The complete genome of HBV isolated from a multi-drug refractory patient was amplified and cloned, and 22 clones were selected for sequencing. The homology of the full-length genome between clones ranged from 98.7% to 99.9%. A precore stop codon mutation of G1896A and basic core promoter (BCP) mutations A1762T/G1764A were detected in a majority of clones. A phylogenetic analysis showed that all clones were classified as subgenotype B2. Three mutations in the surface (S) antigen region, sC76Y, sP120T and sI195M, were detected in 100%, 100% and 77.3% of the clones, respectively. In the core (C) antigen region, a mutation at codon 135 (cP135Q) was detected in 100% of clones. Lamivudine (LAM)-resistant mutations, rtL180M and rtM204V/I were detected in 86.4% of clones. Adefovir (ADV) or entecavir (ETV)-resistant mutations were not detected. Several novel mutations, such as rtT128N, rtA222T, rtS256G, rtL271M, rtS332R, and rtN/T337D, were present in a majority of clones. Furthermore, six pairs of mutations in the overlapping reverse transcriptase (RT) gene and S gene were detected. In conclusion, the complex HBV mutation profile detected in the multi-drug refractory patient highlights the problems associated with the ongoing selection of mutations, including further compensatory mutations as well as potential cross-resistance mutations.

Genotype X/C recombinant (putative genotype I) of hepatitis B virus is rare in Hanoi, Vietnam--genotypes B4 and C1 predominate

There are eight known genotypes of hepatitis B virus, A-H, and several subgenotypes, with rather well-defined geographic distributions. HBV genotypes were evaluated in 153 serum samples from Hanoi, Vietnam. Of the 87 samples that could be genotyped, genotype B was found in 67 (77%) and genotype C in 19 (22%). All genotype C strains were of subgenotype C1, and the majority of genotype B strains were B4, while a few were B2. The genotype X/C recombinant strain, identified previously in Swedish patients of indigenous Vietnamese origin, was found in one sample. This variant, proposed to be classified as genotype I, has been found recently also by others in Vietnam and Laos. The current study indicates that the genotype X/C recombinant may represent approximately 1% of the HBV strains circulating in Vietnam.

[Direct cytopathic effects of particular hepatitis B virus genotypes in immunosuppressive condition]

Little is known about the direct cytopathic effect of hepatitis B virus (HBV) and its association with particular viral genotype or genetic mutation. In some immunosuppressed chronic HBV patients who had liver transplantation or HIV-coinfection, high viremia and liver fibrosis may occur. These findings suggest that hepatic injuries could arise in the absence of a mature immune system and the difference of genotype and/or specific mutation would affect cytopathic potential of the virus. We investigate HBV genotype-related differences in viral replication, antigens expression and histopathology using in vitro replication model or uPA/SCID mice harboring human hepatocytes, demonstrating that different HBV genotypes and even particular mutation are associated with different virological and histopathological characteristics. Infection with HBV/C2 as well as PC mutant of the HBV/B1 in immunosuppressive conditions can induce direct cytopathic effect in "humanized" part of the murine liver.

Microarray for hepatitis B virus genotyping and detection of 994 mutations along the genome

Genome analysis of hepatitis B virus (HBV) in patient sera is helpful for monitoring treatment. We developed an improved version of a DNA microarray to identify HBV genotypes and to detect mutations of interest in the S, Pol, Core, and X genes. It includes an automated software analysis of fluorescence values for simpler, more robust data interpretation. In this version, probes were added to identify genotype H, to analyze 155 additional positions, and to detect 561 additional polymorphisms. Sequences were added to the alignments to resolve hybridization problems due to natural polymorphisms in the vicinity of important codons. The duplex PCR protocol allowed whole-genome analysis in a single tube. An alternative nested-PCR protocol allowed genotyping and mutations in S and reverse transcriptase (rt) genes in patients with low viral loads, as demonstrated in patients with less than 400 HBV genome copies/ml. Reproducibility was high, with variation coefficients lower than 3%. Only 0.57% of 20,771 codons from 253 samples could not be identified. The concordance with Sanger sequencing for the identification of codons improved from 92.8% to 95.7% with the improved version. Concordance was higher than 91% for codons associated with resistance to lamivudine, emtricitabine, telbivudine, famciclovir, entecavir, and tenofovir with vaccine escape and for pre-Core mutants. Concordance was lower for adefovir resistance mutations (68.6%) and mutations in the basal core promoter (60.3%), probably because hybridization efficiency was affected by the low GC content of the probes. A concordance of 93.7% with sequencing for genotype identification was observed in 190 specimens, lower than that obtained with the first version, possibly due to mixed virus populations.

Do we need to determine viral genotype in treating chronic hepatitis B?

Many studies have attested that not only does HBV genotype influence the outcome of the disease but it also influences the outcome of therapy with interferons and pegylated interferons, with genotype A doing better than genotype D in Caucasians and genotype B better than genotype C in Asians. However, the guidelines from three regional bodies - AASLD, APASL and EASL - all stop short of recommending genotyping as part of the management of chronic hepatitis B. The recommendations, however, from several national organizations as well as from individual reviewers suggest that genotyping is essential to detect patients in whom the use of pegylated interferon will give a high likelihood of response with a finite course of therapy and avoid the disadvantages of nucleoside analogues with their viral resistance. It is concluded that determination of HBV genotype should form part of the management in treating chronic hepatitis B.

INNO-LiPA HBV genotyping is highly consistent with direct sequencing and sensitive in detecting B/C mixed genotype infection in Chinese chronic hepatitis B patients and asymptomatic HBV carriers

BACKGROUND

Different HBV genotypes have effect on the progression and outcome of chronic hepatitis B (CHB) and on the response to antiviral therapy. Accurate and sensitive genotyping methods are needed in clinical practice.

METHODS

In this multicenter retrospective study, 504 HBV DNA positive serum or plasma samples of CHB patients or asymptomatic carriers were genotyped by INNO-LiPA HBV genotyping and direct sequencing. A part of the consistent and discrepant results were confirmed by clonal sequencing.

RESULTS

Except two samples with indeterminate results by INNO-LiPA, 463 had the same genotype results by INNO-LiPA and direct sequencing with a concordance of 92.23% (463/502). However 24 had completely inconsistent results by the two methods, seven of which were confirmed by clonal sequencing as the same genotype as by direct sequencing. Fifteen samples were determined as B/C mixed genotypes by INNO-LiPA but singe B or C genotype by direct sequencing, five of which were confirmed by clonal sequencing as B/C mixed infection. Further studies showed INNO-LiPA could detect 6% of genotype B and genotype C among mixed genotype samples at HBV DNA ≥3×10(3) IU/ml.

CONCLUSIONS

INNO-LiPA is accurate and sensitive in detecting B, C, D and B/C mixed genotype infection in Chinese CHB patients and asymptomatic carriers.

Hepatitis B virus genotyping by enzyme-linked immunosorbent assay in Taiwan

PURPOSE

Restriction fragment length polymorphism (RFLP) and enzyme-linked immunosorbent assay (ELISA) with monoclonal antibodies (mAbs) were used in this study to detect genotypes of HBV, and the efficiency and precision of ELISA using the mAbs for HBV genotype detection were also estimated.

METHODS

The ELISA with mAbs method was used for the detection of HBV genotype in a Taiwanese population. The HBV genotypes of 100 chronic hepatitis B patients were determined by ELISA and were then compared with those obtained using RFLP.

RESULTS

Genotype B was found to be the most prevalent in this study (63% by RFLP; 62% by ELISA) followed by genotype C (31% by RFLP; 35% by ELISA). There was no significant difference between the results obtained by RFLP and ELISA (P = 0.75). The ELISA overall genotypeable rate, the correct genotyping rate from genotypeable specimens, and the concordance of the HBV genotyping assay was 96.00, 94.79, and 91.00%; for the ELISA HBV genotyping assay for genotype B specimens was 96.77, 100.00, and 96.77%; and for genotype C specimens was 97.14, 91.18, and 88.57%, respectively. The mean HBV DNA level was higher in the specimens that could be genotyped by both RFLP and ELISA samples (6.24 ± 1.77 vs. 2.34 ± 0.90, log IU/ml), and a significant difference in terms of HBV DNA level of more than 2 × 10(3) IU/ml was identified between the genotyped RFLP samples (P < 0.001).

CONCLUSIONS

ELISA is a practical and a useful method for HBV genotyping in a clinical setting in Taiwan, in particular for patients with lower levels of HBV DNA.

Epidemiological and Clinical Features of Hepatitis B Virus Genotypes among Immigrants in Southern Italy

Background/aims. This study aims to determine the distribution and clinical features of HBV-genotypes in a population of immigrants affected by HBV-infection. Methods. Between 01/2003 and 03/2009, 1623 immigrants were tested for HBV-infection. Biochemical and virological activities were determined in HBsAg-positive patients; HBV-genotypes were determined, by the INNO-LiPA HBV Genotyping, in the subjects with HBV DNA detectable. In every patient we evaluated the stage and classified the infection as inactive carrier, mild or moderate/severe chronic hepatitis, cirrhosis, and/or HCC. Results. Among the tested subjects, 191 (11.7%) resulted HBsAg-positive, and in 144/191 (75.4%) serum HBV-DNA was detectable. The genotype distribution was as follows: 45,13% genotype E, 18,1% genotype D, 15,3% genotype B, 13,2% genotype C, 4,9% genotype A, 3,5% mixed genotypes (A-D). The evaluation of liver disease degree showed that 24.6% patients were inactive carriers of HBV infection, 19.4% presented a immunotolerance phase, 34.5% had mild chronic hepatitis, 13.6% had a moderate/severe chronic hepatitis, 6.3% had cirrhosis, and 1.6% presented HCC. Conclusions. Our study evidences a high prevalence of HBV-infection in immigrants, and the potentiality of migratory flow in the introduction of genotype non-D hepatitis B virus. The Hepatitis B virus genotypes presented significant differences in epidemiological and clinical characteristics.

Current treatments for patients with HBeAg-positive chronic hepatitis B virus infection: a comparison focusing on HBeAg seroconversion

HBeAg seroconversion, in association with undetectable levels of hepatitis B virus DNA as determined by polymerase chain reaction, is an important goal in the treatment of patients with HBeAg-positive chronic hepatitis B (CHB). Achievement of sustained HBeAg seroconversion at an early age (<40 years) is associated with a reduced incidence of hepatic complications, increased rates of HBsAg loss and seroconversion and improved survival rates, whether the seroconversion is spontaneous or treatment induced. Patients with HBeAg-positive CHB who achieve sustained HBeAg seroconversion and complete 6-12 months of consolidation therapy are eligible for stopping therapy. In randomized clinical studies involving patients with HBeAg-positive CHB, treatment with pegylated interferon (PegIFN)-alpha is associated with higher and more durable HBeAg seroconversion rates than are lamivudine and adefovir. More recently, newer generation oral nucleos(t)ide analogs (NAs) have become available. These include entecavir, telbivudine and tenofovir, and they demonstrate superior antiviral potency and efficacy. This review examines the importance of HBeAg seroconversion as an end point for therapy in the treatment of patients with HBeAg-positive CHB, and examines the rates and durability of HBeAg seroconversion with PegIFN and oral NA therapy. The mechanisms for enhanced HBeAg seroconversion rates with new-generation NAs are also discussed.

Drug delivery systems and liver targeting for the improved pharmacotherapy of the hepatitis B virus (HBV) infection

In spite of the progress made in vaccine and antiviral therapy development, hepatitis B virus (HBV) infection is still the most common cause of liver cirrhosis and hepatocellular carcinoma, with more than 400 million people chronically infected worldwide. Antiviral therapy with nucleos(t)ide analogues and/or immunomodulating peptides is the only option to control and prevent the progression of the disease in chronic hepatitis B (CHB)-infected patients. So far, the current antiviral monotherapy remains unsatisfactory because of the low efficacy and the development of drug resistance mutants. Moreover, viral rebound is frequently observed following therapy cessation, since covalent closed circular DNA (cccDNA) is not removed from hepatocytes by antiviral therapy. First, this review describes the current pharmacotherapy for the management of CHB and the new drug candidates being investigated. Then, the challenges in the development of drug delivery systems for the targeting of antiviral drugs to the liver parenchyma are discussed. Finally, perspectives in the design of a more efficient pharmacotherapy to eradicate the virus from the host are addressed.

Efficacy and resistance of entecavir following 3 years of treatment of Japanese patients with lamivudine-refractory chronic hepatitis B

PURPOSE

Lamivudine treatment of chronic hepatitis B (CHB) is associated with frequent resistance and loss of clinical benefit. We present outcomes of lamivudine-refractory Japanese patients treated with entecavir for 3 years.

METHODS

Eighty-two patients refractory to lamivudine therapy received entecavir 0.5 or 1 mg daily for 52 weeks in phase II study ETV-052, directly entered rollover study ETV-060, and received entecavir 1 mg daily. Responses were evaluated among patients with available samples.

RESULTS

After 96 weeks in ETV-060 (148 weeks total entecavir treatment time), 55%(36/65) of patients had hepatitis B virus(HBV) DNA of\400 copies/mL, 85% (52/61) had alanine aminotransferase (ALT) of ≤1 × upper limit of normal (ULN), and 14.6% (7/48) achieved HBe seroconversion.A subset of 42 patients received entecavir 1 mg from phase II baseline through 148 weeks: 54% (19/35) had HBV DNA of <400 copies/mL, 84% (27/32) had ALT of ≤1 × ULN, and 15% (4/27) achieved HBe seroconversion.Sixteen patients in the 1-mg subset had baseline and week 148 evaluable biopsy pairs: 81% (13/16) showed histologic improvement and 38% (6/16) showed improvement in fibrosis. Genotypic resistance to entecavir emerged in 31 patients for a 3-year cumulative resistance probability of 35.9%. Entecavir was generally well tolerated during ETV-060, with no on-treatment ALT flares.

CONCLUSIONS

Long-term entecavir treatment of lamivudine-refractory CHB resulted in virologic suppression, ALT normalization, and improvements in liver histology. Resistance was consistent with that observed in worldwide studies.

Lamivudine maintenance beyond one year after HBeAg seroconversion is a major factor for sustained virologic response in HBeAg-positive chronic hepatitis B

The reported durability of virologic response after successful lamivudine monotherapy is variable, and the question remains as to whether virologic responses can be maintained over an extended follow-up period. The aim of this study was to investigate posttreatment durability, the optimal duration of additional treatment after HBeAg clearance or seroconversion, and determinants for sustained virologic response (SVR) following lamivudine monotherapy in patients with HBeAg-positive chronic hepatitis B (CHB). From January 1999 to August 2004, 178 Korean patients with HBeAg-positive CHB were treated with lamivudine and achieved complete responses, defined as a loss of serum HBeAg and hepatitis B virus DNA, and alanine aminotransferase normalization. The mean duration of lamivudine monotherapy was 26 months (range, 12-77). SVR was maintained in 138 patients (77.5%). Host and viral factors were compared between 138 patients with SVR and 40 patients whose response was not sustained. The cumulative relapse rates increased from 15.9% at 1 year to 30.2% at 5 years, with a mean time to relapse after cessation of lamivudine of 12 months (range, 7-42). Most relapses occurred within 2 years after discontinuation of lamivudine (33/40, 82.5%). On multivariate analysis, age <or=40 years and additional treatment for more than 12 months after HBeAg clearance or seroconversion were independent factors for SVR.

CONCLUSION

The lamivudine-induced virologic response was durable in patients under 40 years old and those receiving lamivudine for more than 12 months after HBeAg clearance or seroconversion. Age and additional treatment were major predictive factors for SVR.

Novel method for genotyping hepatitis B virus on the basis of TaqMan real-time PCR

Chronic infection with hepatitis B virus (HBV) is an important cause of cirrhosis and cancer of the liver. HBV is currently classified into eight genotypes, A to H. Accumulated evidence shows that the genotype influences both the clinical course of infection and the response to treatment. We describe a new method for genotyping based on TaqMan real-time PCR, which identifies all HBV genotypes without post-PCR processing. In this assay, each sample is processed in four multiplex real-time PCRs, each targeting two or three genotype-specific segments of HBV. By analyzing 185 samples representing all genotypes and different proportions of genotype mixtures, we could validate high accuracy of the assay. We conclude that this new assay represents a significant advancement for both diagnostics and clinical research because it is accurate, practical, and based on a technique that is well established in many virological laboratories.

New scoring system for predicting relapse after lamivudine-induced hepatitis B e-antigen loss in chronic hepatitis B patients

AIM

In endemic areas of hepatitis B virus (HBV) infection, lamivudine-induced hepatitis B e-antigen (HBeAg) loss is not durable. We developed a scoring system to predict the relapse after lamivudine-induced HBeAg loss.

METHODS

Of 93 HBeAg-positive chronic hepatitis B patients receiving lamivudine therapy, we studied the 30 patients who achieved HBeAg loss. Qualitative polymerase chain reaction assays for HBV DNA were performed after HBeAg loss; if results were negative on two consecutive occasions, lamivudine treatment was stopped. Serum HBV DNA levels at the time of HBeAg loss were determined using stored serum by the Cobas Amplicor HBV Monitor Kit.

RESULTS

Cumulative relapse rates were 44%, 55.8% and 59.8%, after 1, 2 and 5 years, respectively. Univariate analysis showed that the risk factors for relapse were age (>/= 30 years), HBV DNA level (>/= 60 IU/mL) at the time of HBeAg loss and liver cirrhosis. Independent risk factors for relapse were age (odds ratio [OR], 4.3; 95% confidence interval [CI], 1.2-17.6) and serum HBV DNA level at the time of HBeAg loss (OR, 5.1; 95% CI, 1.3-21.6). We developed a scoring system based on these independent risk factors. No relapse was observed for patients with a risk score of 0. For patients with a risk score of 1, the relapse rates were 41%, 49% and 56% at 1, 2 and 5 years, respectively. All patients with a risk score of 2 relapsed (P = 0.01).

CONCLUSION

Our new scoring system may be useful for predicting relapses in patients with lamivudine-induced HBeAg loss. Treatment strategies should be individualized according to risk score.

Cloning and sequence analysis of complete genome of hepatitis B virus isolates of genotypes B, C, D/C and A from Chinese patients with chronic hepatitis B

AIM: To clone and sequence the complete genome of hepatitis sequence of hepatitis B virus (HBV) isolates of genotypes B, C, D/C and A from the sera of Chinese patients with chronic hepatitis B (CHB).

METHODS: Long-distant polymerase chain reaction (L-PCR) technique was used to amplify the complete genome of HBV isolates from Chinese patients with CHB. After the resulting amplicons were cloned into the TA vector and sequenced, the complete sequences of HBV isolates of genotypes B, C, D/C and A were analyzed using the DNAStar and Simpot software.

RESULTS: The complete genome sequences of HBV isolates of genotypes B, C, D/C and A, which had been deposited into GenBank, were composed of 3215, 3215, 3215 and 3182 bp, respectively. A 33-bp deletion mutation at position 2853-2885 and two point mutations at positions 1762A-T and 1764G-A were observed in one of four clones of sample H3. The coexistence of wild-type and mutant HBV strains in a patient with chronic hepatitis B may provide a molecular basis for the development of drug resistance during antiviral therapy.

CONCLUSION: The complete genome sequences of HBV isolates of genotypes B, C, D/C and A are successfully cloned and can be used as reference sequences for the study of HBV in Chinese patients with chronic hepatitis B.

Subgenotypes of hepatitis B virus genotype D (D1, D2, D3 and D5) in India: differential pattern of mutations, liver injury and occult HBV infection

Hepatitis B genotype D (HBV/D) is the most widespread genotype and exists as at least five subgenotypes (HBV/D1-D5). However, little is known about the association of virological characteristics with clinical differences among HBV/D subgenotypes. To investigate the virological characteristics of these subgenotypes and their clinical implications, we selected a cohort of 109 genotype D infected individuals from the state of West Bengal, India, including 68 HBsAg positive patients and 41 with occult HBV infection. Among the HBsAg positive subjects 28 had chronic hepatitis B virus infection, 40 were asymptomatic carriers based on clinical examination, liver function test and ultrasonograph results. Overall, HBV/D1 was found in 17%, HBV/D2 in 29%, HBV/D3 in 34% and HBV/D5 in 20% of the cases. HBV/D1 was significantly associated with chronic liver disease (P = 0.01), and in this subgenotype A1896 (PreC mutations) were most common. Although BCP mutations (A/C1753 and T1762/A1764) were found to be frequently associated with HBV/D2 (33% and 33%) and D5 (47% and 59%), no apparent clinical correlation was observed. On the other hand, occult HBV infection was significantly associated with HBV/D3 infection, along with low level of BCP and PreC mutations and several non-synonymous substitutions in the catalytic reverse transcriptase (RT) domain of polymerase gene. Similar nucleotide substitutions in the surface (S) gene region were observed from both northern and eastern Indian HBV/D3 isolates. In conclusion, HBV/D subgenotypes differ in their mutational patterns in the S, polymerase and the BCP/PreC regions that may influence their clinical outcomes.

Baseline predictors of virological response for chronic hepatitis B patients

AIM: To determine which baseline factors of chronic hepatitis B patients are predictive of virological response to Peginterferon α-2b therapy.

METHODS: A total of 21 HBeAg-positive chronic hepatitis B (CHB) patients treated with Peginterferon α-2b were recruited. They were treated with Peginterferon α-2b (0.5-1.0 μg/kg per week) for 24 wk and followed up for 24 wk. Clinical and laboratory data of the patients were determined at pretreatment and at week 12, at 24 during treatment, and at week 48 during follow up.

RESULTS: Ten patients achieved a virological response at the end of treatment. Their baseline serum alanine aminotransferase (ALT), thyroid-stimulating hormone (TSH), and total thyroxin (TT4) levels were significantly different from those who failed treatment. The positive predictive values (PPV) and negative predictive values (NPV) of ALT, TSH, and TT4 were 75% and 89 %, 75% and 89 %, and 75% and 75%, respectively. Moreover, combinations of the baseline ALT and TT4, ALT and TSH, TT4 and TSH levels had much higher PPV and NPV (86% and 88%, 89% and 100%, 83% and 100%, respectively).

CONCLUSION: Baseline serum ALT, TSH, and TT4 levels, especially in combination, have high predictive values of virological response to Peginterferon α-2b in HBeAg-positive CHB patients.

Hepatitis B virus: molecular genotypes and HBeAg serological status among HBV-infected patients in the southeast of Brazil

BACKGROUND

Knowledge of HBV genotype is very important for clinical treatment. Studies have suggested possible pathogenic and therapeutic differences among HBV genotypes. The aim of this study was to determine HBV subtypes and genotypes in HBV-infected patients in our region (southeast Brazil) and to correlate results with clinical and histopathological data.

METHODS

One hundred and thirty-nine HBsAg-positive patients were included in the study. All patients were anti-HCV and anti-HIV negative (64% male; mean age 42 +/- 14.5 years; range 7-80 years; 84% Caucasian) and were followed up at the University Hospital. A method for genotyping and subtyping HBV by partial HBsAg gene sequencing with primers common to all known genotypes was used. The viral load was measured by Amplicor Monitor assay (Roche).

RESULTS

HBV genotype A was the most prevalent (55%), while genotypes C, D and F were found in 3%, 38% and 4% of HBV-infected patients, respectively. Among the patients infected by genotype A, 18.3% (14/76) were African descendents and, among the patients infected by genotype D, 11.3% (6/53) were also African descendents. In the four patients infected with genotype C, 2 were Asian descendents and 2 were Caucasians. All (7) genotype F infected patients were Caucasians. Seventy percent of our HBsAg-positive patients were HBeAg negative (62% genotypes A; 26.2% D; 7.1% C and 4.7%F). The viral load of HBV-DNA was about 5 times higher in HBeAg-positive than in HBeAg-negative patients. About 40% of these patients had alanine aminotransferase of up to 1.5 times the normal level. The mean stage of fibrosis in genotype A patients (2.8) was significantly higher than the mean stage of fibrosis in genotype D patients (2.0) (P = 0.0179).

CONCLUSION

The genotypes encountered in our HBV-infected patients were apparently a consequence of the types of immigration that occurred in our region, where European and African descendents predominate. The HBeAg-negative status predominated, possibly due to the length of time of infection. The viral load in HBeAg-positive patients was higher than in HBeAg-negative individuals. The fibrosis grade in genotype A-infected patients was more advanced than genotype D-infected patients.

Prevalence of hepatitis B virus genotype B in Vietnamese patients with chronic hepatitis B

PURPOSE

Hepatitis B virus (HBV) genotypes can affect treatment response to interferon-based therapy and disease outcomes in patients with chronic hepatitis B (CHB). Little data exist to characterize HBV genotypes in Vietnamese, one of the largest minority groups in the United States and also one with one of the highest CHB and liver cancer disease burdens. The goal of this study was to compare the distribution of HBV genotypes in Vietnamese and Chinese patients.

METHODS

We performed a cross-sectional study of 567 consecutive patients of Vietnamese (n = 478) or Chinese (n = 89) descent, with HBV genotype mutation analysis performed between 7/2,005 and 6/2,008 at a community gastroenterology clinic and a university-affiliated liver clinic in the United States.

RESULTS

There were no significant differences between the Vietnamese and Chinese groups in mean age (45 and 44 years), gender (58% and 61% male), HBeAg status (64% and 65% negative), median alanine aminotransferase (33 and 41 U/L), and log(10) HBV DNA (4.9 and 5.0 log(10) IU/ml), or the prevalence of precore/basic core promoter mutations (72% and 71%), respectively. Vietnamese patients had a much higher prevalence of HBV genotype B and a lower prevalence of genotype C than Chinese patients: 74% and 25% vs. 55% and 43% (P = 0.001).

CONCLUSIONS

Chinese patients with CHB often carry either B or C genotype. Vietnamese patients with CHB mostly have HBV genotype B. Additional studies are needed to further characterize the clinical significance of HBV genotype in the natural history and treatment outcomes of CHB in Vietnamese patients.

Hepatitis B virus basal core promoter mutation and DNA load correlate with expression of hepatitis B core antigen in patients with chronic hepatitis B

BACKGROUND

Expression of intrahepatic hepatitis B core antigen (HBcAg) is related to the immunopathogenesis of hepatitis B virus (HBV) infection. This study investigated the role that HBV genotype and basal core promoter (BCP) mutation play in the expression of HBcAg.

METHODS

A total of 70 hepatitis B e antigen (HBeAg)-positive patients with chronic hepatitis (genotype B in 52 patients and genotype C in 18 patients; BCP mutation T1762/A1764 in 16 patients) were enrolled. Clinical, virologic, and histologic features were compared with regard to localization and expression of intrahepatic HBcAg. The effects that HBV genotype and BCP mutation T1762/A1764 had on expression of HBcAg were further evaluated by in vitro assays.

RESULTS

Cytoplasmic, mixed cytoplasmic/nuclear, and nuclear localization of intrahepatic HBcAg was found in 38 (56.7%), 25 (37.3%), and 4 (6.0%) patients, respectively; HBcAg was not discernible in 3 patients. A total of 58 (82.9%) of these patients expressed a high level of HBcAg. In multivariate analysis, cytoplasmic localization of HBcAg correlated only with a low HBV load in serum (P = .045) and BCP mutation (P = .04). A high expression level of HBcAg also correlated with a high HBV load in serum (P = .015) and with BCP wild-type sequence (P = .037). In vitro assays indicated that the HBV BCP mutant strain had lower subcellular expression of HBcAg than did the BCP wild-type strain.

CONCLUSIONS

HBV BCP mutation and HBV load, but not genotype, contribute to the expression of intrahepatic HBcAg.

Hepatitis B virus genotype-associated variability in antiviral response to adefovir dipivoxil therapy in Chinese Han population

It is well known that different genotypes of hepatitis B virus (HBV) have a different sensitivity to interferon-alpha or lamivudine (nucleoside analogue) antiviral therapy. However, for adefovir dipivoxil (ADV, a nucleotide analogue), the antiviral response of the different genotypes remains to be clarified. In order to evaluate the response of HBV genotypes to ADV therapy and to identify factors that might affect initial virological response, we performed a retrospective analysis on patients with chronic hepatitis B (CHB) in Chinese Han population. The study included 183 patients, who had been tested positive for hepatitis B e antigen (HBeAg) and had been treated with ADV (10 mg/day) for 48 weeks. The numbers of patients infected with HBV genotype B and genotype C were 98 and 75 cases, respectively, and the remaining 10 patients were mixture infection of genotypes B plus C or genotypes B plus D. The mean HBV-DNA reduction and HBV-DNA seroclearance of genotypes B and C at 48 weeks were 3.6 log(10) and 3.1 log(10) copies/ml (p < 0.05) and 41.8% and 34.6% (p < 0.05), respectively. There were no statistically significant differences between genotypes B and C in terms of HBeAg loss, anti-HBe seroconversion and normalization of serum alanine aminotransferase (ALT). Multivariate analysis showed that young age, low pretreatment HBV-DNA and/or elevated ALT level might be independent predictive factors associated with initial virological response. Thus, in Han CHB patients who are HBeAg-positive, HBV genotype B shows a better virological response to ADV therapy than does genotype C.

Association of baseline viral factors with response to lamivudine therapy in chronic hepatitis B patients with high serum alanine aminotransferase levels

Background

With the exception of alanine aminotransferase (ALT) level, baseline factors predictive of therapeutic response to lamivudine in patients with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB) remain unknown. We thus studied the influence of pre-therapy viral factors on end-of-treatment responses to lamivudine.

Methods

A total of 116 treatment-naive HBeAg-positive CHB patients who had pre-therapy ALT level >5x the upper limit of normal (ULN) and received lamivudine for 12–18 months were enrolled. HBeAg seroclearance and combined HBeAg seroclearance, ALT normalization and undetectable hepatitis B virus DNA at the end of therapy were defined as primary and secondary endpoints, respectively. Pre-therapy viral factors including viral load, genotype, precore (PC) stop codon status, basal core promoter status and pre-S deletion were determined to correlate with therapeutic endpoints.

Results

The frequency of patients with detectable PC stop codon mutation (G1896A), basal core promoter mutation (A1762T/G1764A) and pre-S deletion at baseline was 22.4%, 21.6% and 12.1%, respectively. After the end of 12–18 months of lamivudine therapy, the overall HBeAg seroclearance rate was 56.0%. Patients with HBeAg seroclearance had a higher prevalence of baseline PC stop codon mutation than those without (30.8% versus 11.8%; P=0.015). By using multivariate analyses, the odds ratio of patients with the PC stop codon mutation to develop HBeAg seroclearance was 3.33 ( P=0.024). The presence of the PC stop codon mutation also correlated with the combined response.

Conclusions

For lamivudine-treated HBeAg-positive CHB patients with pre-therapy ALT levels >5xULN, the PC stop codon mutation could predict a higher HBeAg seroclearance rate at the end of 12–18 months of therapy.

A treatment algorithm for the management of chronic hepatitis B virus infection in the United States: 2008 update

Chronic HBV infection is an important public health problem worldwide and in the United States. A treatment algorithm for the management of this disease, published previously by a panel of U.S. hepatologists, has been revised on the basis of new developments in the understanding of the disorder, the availability of more sensitive molecular diagnostic tests, and the licensure of new therapies. In addition, a better understanding of the advantages and disadvantages of new treatments has led to the development of strategies for reducing the rate of resistance associated with oral agents and optimizing treatment outcomes. This updated algorithm was based primarily on available evidence by using a systematic review of the literature. Where data were lacking, the panel relied on clinical experience and consensus expert opinion. The primary aim of antiviral therapy is durable suppression of serum HBV DNA to low or undetectable levels. Assays can now detect serum HBV DNA at levels as low as 10 IU/mL and should be used to establish a baseline level, monitor response to antiviral therapy, and survey for the development of drug resistance. Interferon alfa-2b, lamivudine, adefovir, entecavir, peginterferon alfa-2a, telbivudine, and tenofovir are approved as initial therapy for chronic hepatitis B and have certain advantages and disadvantages. Although all of these agents can be used in selected patients, the preferred first-line treatment choices are entecavir, peginterferon alfa-2a, and tenofovir. Issues for consideration for therapy include efficacy, safety, rate of resistance, method of administration, and cost.

Inhibition of HBV gene expression and replication by stably expressed interferon-alpha1 via adeno-associated viral vectors

Background

Interferon‐α2 (IFNα2) is routinely used for anti‐hepatitis B virus (HBV) treatment. However, the therapeutic efficiency is unsatisfactory, particularly in East Asia. Such inefficiency might be a result of the short half‐life, relatively low local concentration and strong side‐effects of interferons. Frequent and repeated injection is also a big burden for patients. In the present study, a single dose of vector‐delivered IFNα1 was tested for its anti‐HBV effects.

Methods

Adeno‐associated viral vector (AAV‐IFNα1) was generated to deliver the IFNα1 gene into hepatocytes. IFNα1, hepatitis B surface (HBsAg) and e (HBeAg) antigens were measured by enzyme‐linked immunosorbent assay and/or western blotting. The level of viral DNA was measured by quantitative real‐time polymerase chain reaction.

Results

AAV‐IFNα1 effectively transduced HBV‐producing cells (HepAD38) and mouse hepatocytes, where IFNα1 was expressed in a stable manner. Both intracellular and extracellular HBsAg and HBeAg were significantly reduced in vitro. In the HBV‐producing mice, the concentration of IFNα1 in the liver was eight‐fold higher than that in plasma. Compared with control groups, HBeAg/HBsAg antigen levels were reduced by more than ten‐fold from day 1–5, and dropped to an undetectable level on day 9 in the AAV‐IFNα1 group. Concurrently, the level of viral DNA decreased over 30‐fold for several weeks.

Conclusions

A single dose administration of AAV‐IFNα1 viral vector displayed prolonged transgene expression and superior antiviral effects both in vitro and in vivo. Therefore, the use of AAV‐IFNα1 might be a potential alternative strategy for anti‐HBV therapy. Copyright © 2008 John Wiley & Sons, Ltd.

Treatment recommendations for chronic hepatitis B: an evaluation of current guidelines based on a natural history study in the United States

Current guidelines for treatment of chronic hepatitis B include hepatitis B e antigen (HBeAg) status, levels of hepatitis B virus (HBV) DNA, and serum alanine aminotransferase (ALT) values in the setting of either chronic hepatitis or cirrhosis. Based on findings from a prospective study of hepatitis B surface antigen (HBsAg)-positive patients, we determined whether these guidelines included patients who developed hepatocellular carcinoma (HCC) and who died of non-HCC liver-related complications. The criteria for treatment from four published guidelines were matched to a cohort of 369 HBsAg-positive patients enrolled in the study. During a mean follow-up of 84 months, 30 patients developed HCC and 37 died of non-HCC liver-related deaths. Using criteria for antiviral therapy as stated by the four guidelines, only 20%-60% of the patients who developed HCC, and 27%-70% of patients who died of non-HCC liver-related deaths would have been identified for antiviral therapy according to current treatment recommendations. If baseline serum albumin levels of 3.5 mg/dL or less or platelet counts of 130,000 mm(3) or less were added to criteria from the four treatment guidelines, then 89%-100% of patients who died of non-HCC liver-related complications, and 96%-100% of patients who developed HCC would have been identified for antiviral therapy. In addition, if basal core promoter T1762/A1764 mutants and precore A1896 mutants also were included, then 100% of patients who developed HCC would have been identified for treatment.

CONCLUSION

This retrospective analysis showed that the current treatment guidelines for chronic hepatitis B excluded patients who developed serious liver-related complications.

Associations between hepatitis B virus genotype and mutants and the risk of hepatocellular carcinoma

Background

The risk of hepatocellular carcinoma (HCC) increases with increasing level of hepatitis B virus (HBV) in serum (viral load). However, it is unclear whether genetic characteristics of HBV, including HBV genotype and specific genetic mutations, contribute to the risk of HCC. We examined the HCC risk associated with HBV genotypes and common variants in the precore and basal core promoter (BCP) regions.

Methods

From January 5, 1991, to December 21, 1992, baseline blood samples were collected from 2762 Taiwanese men and women who were seropositive for HBV surface antigen but had not been diagnosed with HCC; the samples were tested for HBV viral load by real-time polymerase chain reaction and genotyped by melting curve analysis. Participants who had a baseline serum HBV DNA level greater than 10⁴ copies/mL (n = 1526) were tested for the precore G1896A and BCP A1762T/G1764A mutants by direct sequencing. Incident cases of HCC were ascertained through follow-up examinations and computerized linkage to the National Cancer Registry and death certification profiles. A Cox proportional hazards model was used to estimate the risk of HCC associated with HBV genotype and precore and BCP mutants after adjustment for other risk factors. All statistical tests were two-sided.

Results

A total of 153 HCC cases occurred during 33 847 person-years of follow-up. The HCC incidence rates per 100 000 person-years for participants infected with HBV genotype B or C were 305.6 (95% confidence interval [CI] = 236.9 to 388.1) and 785.8 (95% CI = 626.8 to 972.9), respectively. Among participants with a baseline HBV DNA level of at least 10⁴ copies/mL, HCC incidence per 100 000 person-years was higher for those with the precore G1896 (wild-type) variant than for those with the G1896A variant (955.5 [95% CI = 749.0 to 1201.4] vs 269.4 [95% CI = 172.6 to 400.9]) and for those with the BCP A1762T/G1764A double mutant than for those with BCP A1762/G1764 (wild-type) variant (1149.2 [95% CI = 872.6 to 1485.6] vs 358.7 [95% CI = 255.1 to 490.4]). The multivariable-adjusted hazard ratio of developing HCC was 1.76 (95% CI = 1.19 to 2.61) for genotype C vs genotype B, 0.34 (95% CI = 0.21 to 0.57) for precore G1896A vs wild type, and 1.73 (95% CI = 1.13 to 2.67) for BCP A1762T/G1764A vs wild type. Risk was highest among participants infected with genotype C HBV and wild type for the precore 1896 variant and mutant for the BCP 1762/1764 variant (adjusted hazard ratio = 2.99, 95% CI = 1.57 to 5.70, P < .001).

Conclusions

HBV genotype C and specific alleles of BCP and precore were associated with risk of HCC. These associations were independent of serum HBV DNA level.

Inspection and analysis of hepatitis B virus genotypes among the korean nationality of Yanbian area in China

AIM: To investigate the distribution and clinical significance of hepatitis B virus (HBV) genotypes among the Korean Chinese of Yanbian area in China.

METHODS: A total of 215 Korean Chinese with HBV infection in Yanbian area included symptomatic carrier (SC, n = 36), acute hepatitis B (AHB, n = 5), chronic hepatitis B (CHB, n = 106), hepatitis-induced cirrhosis (HC, n = 50), and primary hepatic carcinoma (HCC, n = 18). Specific primer-polymerase chain reaction was used to detect the HBV genotypes in this cases.

RESULTS: Of the 215 cases, genotype B and C were found in 61 (28.0%) and 154 (72.0%) cases, respectively. The ratio of genotype C was markedly higher in CHB (79.0%), HC (84.0%), HCC (89.0%) than that in SC (25.0%) and AHB (60.0%), respectively (P < 0.05). In SC, the proportion of genotype B was significantly higher than that of genotype C (75.0% vs 25.0%, P < 0.01). The rate of genotype C was higher in the HBeAg-positive cases than that in the HbeAg-negative cases (73.0% vs 54.0%, P < 0.05), but the rate of genotype B was the other way around (46.0% vs 27.0%, P < 0.01).

CONCLUSION: Genotype C HBV infection is predominant in the Korean Chinese of Yanbian area in China, and genotype B is the second. Genotype C is mostly found in CHB, HC and HCC.