Seroconversion from hepatitis B e antigen to anti-HBe in chronic hepatitis B virus infection

Cellular Factors Involved in the Hepatitis D Virus Life Cycle

Hepatitis D virus (HDV) is a defective RNA virus with a negative-strand RNA genome encompassing less than 1700 nucleotides. The HDV genome encodes only for one protein, the hepatitis delta antigen (HDAg), which exists in two forms acting as nucleoproteins. HDV depends on the envelope proteins of the hepatitis B virus as a helper virus for packaging its ribonucleoprotein complex (RNP). HDV is considered the causative agent for the most severe form of viral hepatitis leading to liver fibrosis/cirrhosis and hepatocellular carcinoma. Many steps of the life cycle of HDV are still enigmatic. This review gives an overview of the complete life cycle of HDV and identifies gaps in knowledge. The focus is on the description of cellular factors being involved in the life cycle of HDV and the deregulation of cellular pathways by HDV with respect to their relevance for viral replication, morphogenesis and HDV-associated pathogenesis. Moreover, recent progress in antiviral strategies targeting cellular structures is summarized in this article.

Effect of the change in antiviral therapy indication on identifying significant liver injury among chronic hepatitis B virus infections in the grey zone

Objective

In clinical practice, a substantial proportion of chronic hepatitis B virus (HBV) infections that do not fit into any of the usual immune states are considered to be in the “grey zone (GZ)”. This study aimed to investigate the effect of the change in antiviral therapy indication on identifying significant hepatic injury among GZ patients.

Methods

Patients with chronic HBV infections and a persistent normal alanine aminotransferase (ALT) level (PNALT) who underwent ultrasonography-guided percutaneous liver biopsy were examined retrospectively. Evidenced hepatic injury (EHI) was defined as an inflammation grade ≥2 (≥G2) and/or fibrosis stage ≥2 (≥F2). Complete clinical data, liver inflammation, and fibrosis grades were collected, and the levels of cytokines were detected by the Luminex technique, all of which were analysed to investigate the immune and histopathology states of the liver.

Results

A total of 347 patients with chronic HBV infections and PNALT were categorized into immune tolerant (IT, n = 108), inactive HBV surface antigen (HBsAg) carrier (IHC, n = 61), GZ-1 (HBeAg positive in GZ, n = 92), and GZ-2 (HBeAg negative in GZ, n = 68) phases. Among them, 51.3% were in the GZ phase, and 50.1% presented with EHI. The IL-6 levels were higher in the EHI group than in the non-EHI group (2.77 vs. 1.53 pg/ml, Z = −13.32, p = 0.028). The monocyte chemoattractant protein 1 (MCP-1) level was positively correlated with HBV DNA (R = 0.64, p < 0.001) and HBeAg (R = 0.5, p < 0.001) but negatively correlated with fibrosis grade (R = −0.26, p = 0.048). The ratio of EHI in the GZ phase was 60.55%, which was significantly higher than that in patients in the IT (39.8%) and IHC phases (37.7%) (χ² = 10.4, p = 0.006). A total of 46.69% of all patients exceeded the new ALT antiviral treatment threshold (30 U/L for men and 19 U/L for women). The EHI values in the IT and IHC phases below the new ALT threshold were 32.6% and 37.8%, respectively, whereas higher EHI values of 67.4% and 68.4% were seen in GZ-1 and GZ-2 patients, respectively, exceeding the new ALT threshold, and the difference was statistically significant (χ² = 11.13, p < 0.001; χ² = 14.22, p = 0.002). The median age in our cohort was 38.91 years, and only 21.03% were less than 30 years old. The EHI values in the IT and IHC patients <30 years old were 32.4% and 35.8%, respectively, while the ratio of EHI increased to 43.2% once patients were older than 30 years but still in the IT and IHC stages.

Conclusion

Setting 30 years old as a cut-off and lowering the ALT threshold could facilitate screening for the presence of significant liver injury, especially for GZ patients. IL-6 was a good indicator of EHI, and MCP-1 was significantly positively correlated with HBV DNA but negatively correlated with liver fibrosis.

[Natural history and disease progression of chronic hepatitis B virus infection]

OBJECTIVE

To better understand and revise the natural history and disease progression of chronic hepatitis B virus (HBV) infection through analysis of a single-center large-scale cohort of indivi-duals with chronic HBV infection.

METHODS

Patients with chronic HBV infection who had undergone liver biopsy in the Fifth Medical Center of Chinese People's Liberation Army (PLA) General Hospital from January 2014 to October 2020 were retrospectively recruited. Based on patient's hepatitis B e antigen (HBeAg) states and pathologic diagnosis, they were categorized into four disease progression statuses (or phases according to the old-terminology in the updated guidelines of chronic hepatitis B (CHB), such as European Association for the Study of the Liver (EASL) 2017, Clinical Practice Guidelines on the Management of Hepatitis B Virus Infection: HBeAg-positive chronic HBV infection (immune tolerance), HBeAg-positive CHB (immune active HBeAg positive), HBeAg-negative chronic HBV infection (inactive carrier), and HBeAg-negative CHB (immune reactive HBeAg negative). Then the demographic, laboratory tests and liver histological results of the patients in different disease progression stages were compared. Age differences between the two groups were evaluated using Mann-Whitney U test.

RESULTS

A total of 760 eligible patients with a median age of 29 (interquartile range: 16-39) years were enrolled. Among them, 197 were underage individuals (age < 18 years) and 563 were adults; and 456 were males and 304 females. According to the pathological diagnosis, the patients were classified, and in each of the above four natural disease phases there were 173, 329, 95, and 163 individuals, respectively. Further comparison of the ages of the patients of the four disease progression statuses revealed that patients of HBeAg-negative CHB had a median age at 37 years, which was reasonably higher than those with HBeAg-positive CHB in immune active phase (37 vs. 24 years, P < 0.001), but was relatively younger than those with HBeAg-negative chronic HBV infection (37 vs. 39 years, P= 0.240).

CONCLUSION

According to this study, it could be speculated that HBeAg-negative CHB patients probably not all reactivate from individuals of HBeAg-negative chronic HBV infection. Instead, certain HBeAg-negative CHB patients may also come from HBeAg-positive CHB patients who have undergone HBeAg clearance or seroconversion and still remain in the immune active state.

Comparison of biochemical response during antiviral treatment in patients with chronic hepatitis B infection

BACKGROUND & AIMS

This multicenter cohort study aimed to compare the real-world biochemical response rates during tenofovir alafenamide (TAF), tenofovir disoproxil fumarate (TDF), and entecavir (ETV) treatment in chronic hepatitis B virus (HBV) infection patients.

METHODS

Overall, 1282 treatment-naïve patients with CHB who commenced TAF (n = 270), TDF (n = 617), or ETV (n = 395) were analysed for biochemical response rates during the antiviral treatment using a time-dependent Cox proportional hazard model after the inverse probability of treatment weighting (IPTW).

RESULTS

Patients treated with ETV were older (55.1 ± 11.5 years) than TAF or TDF (P < .0001). ETV was more frequently prescribed to patients with diabetes mellitus (DM, P = .003), hypertension (P < .0001), chronic kidney disease (P < .0001), and negative e-antigen (P < .0001). Cumulative biochemical response rate was independently lower in patients with radiologic fatty liver (HR, 0.75; 95% CI, 0.61-0.94) and obese patients without DM (HR, 0.85; 95% CI, 0.68-0.98) according to multivariable Cox analyses based on time-dependent variables after IPTW for age, sex, liver cirrhosis, baseline e-antigen, ALT, and HBV DNA levels. ETV treated patients (HR, 1.38; 95% CI, 1.13-1.68) showed higher biochemical response rates compared with TAF- or TDF-treated patients after adjusting for similar parameters.

CONCLUSIONS

In real-world practice, ETV was preferable for older, hepatitis B e-antigen negative patients with underlying comorbidities. Biochemical responses in patients treated with ETV, TAF, and TDF were significantly affected by metabolic factors such as fatty liver, obesity, and DM. However, the mechanism behind the higher biochemical response rate in patients treated with ETV should be investigated further.

Modeling the dynamics of hepatitis B infection, immunity, and drug therapy

Hepatitis B virus infection is the cause of liver diseases such as cirrhosis and liver cancer. Understanding the host-virus mechanisms that mediate virus pathogenesis can help design better preventive measures for disease control. Mathematical models have been used alongside experimental data to provide insight into the role of immune responses during the acute and chronic hepatitis B infections as well as virus dynamics following administration of combined drug therapy. In this paper, we review several modeling studies on virus-host interactions during acute infection, the virus-host characteristics responsible for transition to chronic disease, and the efficacy and optimal control measures of drug therapy. We conclude by presenting our opinion on the future directions of the field.

Smaller reduction of hepatitis B virus DNA in liver tissue than in serum in patients losing HBeAg

The prognosis and outcome of treatment for chronic hepatitis B virus (HBV) infection are predicted by levels of HBV DNA in serum. These levels are composed of relaxed circular DNA (rcDNA) and double stranded linear DNA in viral particles, whereas, HBV DNA in liver tissue also can be covalently closed circular DNA (cccDNA) or integrated into the human genome. The aim of this study was to investigate the quantitative relation between HBV DNA in serum and tissue, its change over time and how these markers relate to serum levels of hepatitis B surface antigen (HBsAg). Serum and liver biopsies taken from 15 patients with chronic HBV infection on two occasions during 2.7-11.1 years were analyzed retrospectively. At baseline, the median HBV DNA levels in serum were 7.76 log₁₀  IU/mL in nine hepatitis B e antigen (HBeAg) positive and 3.65 log₁₀ IU/mL in six HBeAg-negative patients. At follow-up, serum HBV DNA, serum HBsAg, and intrahepatic HBV DNA (ihDNA) levels had declined by 4.36, 0.52, and 1.47 log₁₀ units, respectively, in seven patients that lost HBeAg, whereas the corresponding reductions were 0.36, 0.30, and 0.39 log₁₀ units in eight patients with unchanged HBeAg status. We conclude that HBV DNA in liver tissue declined almost 1000 times less than HBV DNA in serum during and after loss of HBeAg. This finding raises the possibility that integrated sequences constitute a significant part of the ihDNA. Alternatively, the greater decline of HBV DNA in serum might be due to yet unknown mechanisms acting downstream of reverse transcription.

Hepatitis B Virus e Antigen Activates the Suppressor of Cytokine Signaling 2 to Repress Interferon Action

Hepatitis B virus (HBV) infection causes acute hepatitis B (AHB), chronic hepatitis B (CHB), liver cirrhosis (LC), and eventually hepatocellular carcinoma (HCC). The presence of hepatitis B e antigen (HBeAg) in the serum generally indicates ongoing viral replication and disease progression. However, the mechanism by which HBeAg regulates HBV infection remains unclear. Interferons (IFNs) are pleiotropic cytokines that participate in host innate immunity. After binding to receptors, IFNs activate the JAK/STAT pathway to stimulate expression of IFN-stimulated genes (ISGs), leading to induction of antiviral responses. Here, we revealed that HBeAg represses IFN/JAK/STAT signaling to facilitate HBV replication. Initially, HBeAg stimulates the expression of suppressor of cytokine signaling 2 (SOCS2). Subsequently, SOCS2 impairs IFN/JAK/STAT signaling through reducing the stability of tyrosine kinase 2 (TYK2), downregulating the expression of type I and III IFN receptors, attenuating the phosphorylation and nucleus translocation of STAT1. Finally, SOCS2 inhibits the expression of ISGs, which leads to the repression of IFN action and facilitation of viral replication. These results demonstrate an important role of HBeAg in the regulation of IFN action, and provide a possible molecular mechanism by which HBV resists the IFN therapy and maintains persistent infection.

Hepatitis B: 50 years after the discovery of Australia antigen

It is an honour to be invited to recount the progress in our understanding and management of hepatitis B 50 years after the discovery of Australia antigen (Au Ag). During this half century, we have gone from identifying the causative agent--hepatitis B virus (HBV), understanding its biology and the disease it causes, to having vaccines that can prevent HBV infection and antiviral therapy that can suppress HBV replication and prevent progression of HBV-related liver disease. As a result of the progress, prevalence of HBV infection and morbidity and mortality from chronic HBV infection has declined.

Cost-effectiveness of non-invasive methods for assessment and monitoring of liver fibrosis and cirrhosis in patients with chronic liver disease: systematic review and economic evaluation

BACKGROUND

Liver biopsy is the reference standard for diagnosing the extent of fibrosis in chronic liver disease; however, it is invasive, with the potential for serious complications. Alternatives to biopsy include non-invasive liver tests (NILTs); however, the cost-effectiveness of these needs to be established.

OBJECTIVE

To assess the diagnostic accuracy and cost-effectiveness of NILTs in patients with chronic liver disease.

DATA SOURCES

We searched various databases from 1998 to April 2012, recent conference proceedings and reference lists.

METHODS

We included studies that assessed the diagnostic accuracy of NILTs using liver biopsy as the reference standard. Diagnostic studies were assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. Meta-analysis was conducted using the bivariate random-effects model with correlation between sensitivity and specificity (whenever possible). Decision models were used to evaluate the cost-effectiveness of the NILTs. Expected costs were estimated using a NHS perspective and health outcomes were measured as quality-adjusted life-years (QALYs). Markov models were developed to estimate long-term costs and QALYs following testing, and antiviral treatment where indicated, for chronic hepatitis B (HBV) and chronic hepatitis C (HCV). NILTs were compared with each other, sequential testing strategies, biopsy and strategies including no testing. For alcoholic liver disease (ALD), we assessed the cost-effectiveness of NILTs in the context of potentially increasing abstinence from alcohol. Owing to a lack of data and treatments specifically for fibrosis in patients with non-alcoholic fatty liver disease (NAFLD), the analysis was limited to an incremental cost per correct diagnosis. An analysis of NILTs to identify patients with cirrhosis for increased monitoring was also conducted.

RESULTS

Given a cost-effectiveness threshold of £20,000 per QALY, treating everyone with HCV without prior testing was cost-effective with an incremental cost-effectiveness ratio (ICER) of £9204. This was robust in most sensitivity analyses but sensitive to the extent of treatment benefit for patients with mild fibrosis. For HBV [hepatitis B e antigen (HBeAg)-negative)] this strategy had an ICER of £28,137, which was cost-effective only if the upper bound of the standard UK cost-effectiveness threshold range (£30,000) is acceptable. For HBeAg-positive disease, two NILTs applied sequentially (hyaluronic acid and magnetic resonance elastography) were cost-effective at a £20,000 threshold (ICER: £19,612); however, the results were highly uncertain, with several test strategies having similar expected outcomes and costs. For patients with ALD, liver biopsy was the cost-effective strategy, with an ICER of £822.

LIMITATIONS

A substantial number of tests had only one study from which diagnostic accuracy was derived; therefore, there is a high risk of bias. Most NILTs did not have validated cut-offs for diagnosis of specific fibrosis stages. The findings of the ALD model were dependent on assuptions about abstinence rates assumptions and the modelling approach for NAFLD was hindered by the lack of evidence on clinically effective treatments.

CONCLUSIONS

Treating everyone without NILTs is cost-effective for patients with HCV, but only for HBeAg-negative if the higher cost-effectiveness threshold is appropriate. For HBeAg-positive, two NILTs applied sequentially were cost-effective but highly uncertain. Further evidence for treatment effectiveness is required for ALD and NAFLD.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42011001561.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Manifestations of perihepatic lymph nodes in acute flare of chronic hepatitis B: association with HBeAg status and with HBeAg seroconversion

It has been observed that enlargement of perihepatic lymph nodes may be seen in patients with chronic hepatitis B, particularly during acute flares of CHB. We hypothesized that there may be a correlation between the nodal change patterns in CHB patients with acute flare and HBeAg status. Perihepatic lymph node sizes of 87 patients with acute flares of CHB were documented, with a median follow up of 43 months. Patients were separated into 3 groups, HBeAg-positive with HBe seroconversion (group 1), HBeAg-positive without HBe seroconversion (group 2), and HBeAg-negative (group 3). Group 1 has the highest incidence of enlarged lymph nodes (92.3%) compared with group 2 (75.8%) and group 3 (46.8%) (p = 0.003). And if nodal width at acute flare was > 8mm and interval change of nodal width was >3mm, the incidence of HBeAg seroconversion will be 75% (p<0.001).

Factors affecting the natural decay of hepatitis B surface antigen in children with chronic hepatitis B virus infection during long-term follow-up

OBJECTIVE

To investigate the factors predicting spontaneous clearance of hepatitis B surface antigen (HBsAg) in a long-term, prospectively followed cohort from childhood into adult life.

STUDY DESIGN

Children with chronic hepatitis B virus (HBV) infection without treatment were followed longitudinally every 6 months. At each visit, liver profiles and HBV markers were assessed. Hepatitis B vaccination history and the maternal HBV markers also were studied.

RESULTS

A total of 349 children (205 male) were followed for 20.6 ± 4.4 years with initial ages of 8.4 ± 3.9 years; 42 (12.0%) cleared HBsAg spontaneously. The HBsAg titers decayed with age, with an average annual clearance rate of 0.58%. Children had a lower annual HBsAg decay rate if their mothers are HBsAg carriers (P < .001). Hepatitis B e antigen-seroconversion is a favorable predictor for spontaneous HBsAg clearance (P = .04). Those with HBsAg titer ≤1000 IU/mL at enrollment during childhood have a higher rate of HBsAg clearance (hazard ratio = 5.23; P < .001). Using HBsAg titer ≤1000 IU/mL to predict HBsAg clearance, the sensitivity is 38.1%, specificity is 90.6%, positive predictive value is 35.6%, and negative predictive value is 91.4%.

CONCLUSIONS

During long-term follow-up, spontaneous HBsAg clearance is most likely to occur in a patient born to a non-HBsAg-carrier mother, is a hepatitis B e antigen-seroconverter, and had an initial HBsAg level ≤1000 IU/mL.

Prediction of early HBeAg seroconversion by decreased titers of HBeAg in the serum combined with increased grades of lobular inflammation in the liver

Background

Hepatitis B e antigen (HBeAg) seroconversion is an important hallmark in the natural course of chronic hepatitis B. This study was designed to predict early HBeAg seroconversion within 1 year, by not only biochemical and virological markers, but also pathological parameters in patients with chronic hepatitis B.

Material/Methods

In a retrospective cohort study, 234 patients with HBeAg were reviewed for demographic, biochemical, virological and pathological data at the time of liver biopsy. Then, the patients who accomplished HBeAg seroconversion within 1 year thereafter were compared with those who did not, for sorting out factors predictive of early HBeAg seroconversion.

Results

Early HBeAg seroconversion occurred in 58 (24.8%) patients. In univariate analysis, factors predictive of early HBeAg seroconversion were: alanine aminotransferase (ALT) (p=0.002), IP-10 (p=0.029), HBsAg (p=0.003), HBeAg (p<0.001), HBV DNA (p=0.001), HBcrAg (p=0.001), core-promoter mutations (p=0.040), fibrosis (p=0.033) and lobular inflammation (p=0.002). In multivariate analysis, only serum HBeAg levels <100 Paul Ehrlich Institute (PEI) U/ml and grades of lobular inflammation ≥2 were independent factors for early HBeAg seroconversion (odds ratio 8.430 [95% confidence interval 4.173–17.032], p<0.001; and 4.330 [2.009–9.331], p<0.001; respectively).

Conclusions

HBeAg levels < 100 PEIU/ml combined with grades of lobular inflammation ≥2 are useful for predicting early HBeAg seroconversion. In patients without liver biopsies, high ALT levels (≥200 IU/L) can substitute for lobular inflammation (grades ≥2).

[Characteristics of patients with chronic hepatitis B virus infection. analysis of a series of 474 patients]

OBJECTIVE

To determine the clinical, laboratory, serological and histologic characteristics of chronic hepatitis B virus carriers in our environment.

MATERIAL AND METHODS

A retrospective cohort study was performed that included chronic AgHBs carriers aged more than 13 years attending our service since January 2000.

RESULTS

A total of 474 patients were included. At diagnosis, 55.49% were men, with a mean age of 41.05±13.93 years. Alanine aminotransferase (ALT) levels were within the normal range in 57.17% of the patients, and 87.76% were AgHBe(-). Hepatitis C and D virus coinfection was found in 3.62% and 1.86%, respectively. Liver biopsy was performed in 31.22%; varying grades of inflammation-fibrosis were found in 63.51% and cirrhosis was found in 12.84%. Compared with AgHBe(-) patients, those who were AgHBe(+) were younger and had greater disease activity. This difference was statistically significant. Patients in the immunotolerant phase were the least numerous (5.26%), while AgHBe(-) patients with chronic HBV infection were the most numerous (48.32%). Patients in the immunoreactive phase showed greater histological involvement (16.67% cirrhosis). A familial history of chronic HBV was found in 21.52%. The percentage of non-Spanish patients increased in the last few years and accounted for 18.78%.

CONCLUSION

Chronic HBV infection in our environment occurs mainly in middle-aged persons. GPT values are normal in more than 50%, most are AgHBe(-), and approximately half are inactive carriers. The incidence of chronic infection has increased in the non-Spanish population in recent years.

Neuromuscular disorders associated with hepatitis B virus infection

Approximately 400 million worldwide are chronically infected with the hepatitis B virus (HBV). During the course of illness, approximately 20% of patients develop disease manifestations outside the liver. Neuropathy develops in approximately 5% of patients with chronic HBV infection and rarely during acute HBV infection. The pathogenesis of the various HBV-associated neuropathy syndromes possibly involves deposition of immune complexes in nerves or blood vessel walls. Direct viral infection of nerves has not been demonstrated. Management entailed supportive care with antiviral and immunomodulatory treatment as clinically indicated. Rare cases of muscle disease, mostly inflammatory myopathy, have been associated with HBV infection. Presumably, HBV-associated antigens trigger immune mechanisms directed against components of muscle tissue. There is no evidence of replicative virus infection of muscle fibers. Management entailed immunomodulatory treatment, occasionally with anti-HBV therapy. Physicians should be aware that HBV infection has the potential to trigger presumed immune-mediated neuromuscular syndromes.

Tracking the naturally occurring mutations across the full-length genome of hepatitis B virus of genotype D in different phases of chronic e-antigen-negative infection

Hepatitis B e-antigen (HBeAg)-negative chronic HBV infection is highly prevalent in several parts of the world, including India, with the clinical spectrum ranging from inactive carrier (IC) state to chronic 'e-negative' hepatitis B (CHB) and culminating in advanced liver disease such as cirrhosis (LC). The present study has for the first time investigated the natural diversity of HBV belonging to genotype D in treatment-naïve Indian patients representing the above phases of HBeAg-negative infection to identify candidate mutations associated with each disease state. Studies of full-length HBV/D sequences revealed that the progressive accumulation and persistence of mutations in basal core promoter, negative regulatory element, Pre-core region, the B- and T-cell epitopes of X protein as well as deletions in the PreS region contribute significantly to disease progression from IC through CHB to LC. In addition, the development of CHB was associated with a significant increase in viral variants characterized by mutations in enhancer II, preS1 promoter, T-cell epitope of core and B-cell epitope region of PreS1. While few of the mutations were previously reported in the context of HBV genotypes B and C, others had not been documented before. Our results thus highlight a distinct pattern of mutation in HBV/D that may help in predicting clinical outcomes of HBeAg-negative infection and have implications for better clinical management of the patients.

Mathematical models of e-antigen mediated immune tolerance and activation following prenatal HBV infection

We develop mathematical models for the role of hepatitis B e-antigen in creating immunological tolerance during hepatitis B virus infection and propose mechanisms for hepatitis B e-antigen clearance, subsequent emergence of a potent cellular immune response, and the effect of these on liver damage. We investigate the dynamics of virus-immune cells interactions, and derive parameter regimes that allow for viral persistence. We modify the model to account for mechanisms responsible for hepatitis B e-antigen loss, such as seroconversion and virus mutations that lead to emergence of cellular immune response to the mutant virus. Our models demonstrate that either seroconversion or mutations can induce immune activation and that instantaneous loss of e-antigen by either mechanism is associated with least liver damage and is therefore more beneficial for disease outcomes.

Mechanisms of HBV-related hepatocarcinogenesis

The hepatitis B virus (HBV) is a small enveloped DNA virus, which primarily infects hepatocytes and causes acute and persistent liver disease. Epidemiological studies have provided overwhelming evidence for a causal role of chronic HBV infection in the development of hepatocellular carcinoma, but the molecular mechanisms underlying virally-induced tumourigenesis remain largely debated. In the absence of a dominant oncogene encoded by the HBV genome, indirect roles have been proposed, including insertional activation of cellular cancer-related genes by HBV DNA integration, induction of genetic instability by viral integration or by the regulatory protein HBx, and long-term effects of viral proteins in enhancing immune-mediated liver disease. Recent genetic studies indicate that HBV-related tumours display a distinctive profile with a high rate of chromosomal alterations and low frequency of beta-catenin mutations. This review will discuss the evidence implicating chronic HBV infection as a causal risk factor of primary liver cancer. It will also discuss the molecular mechanisms that are critical for the tumourigenic process due to long lasting infection with HBV.

Predictive factors for early HBeAg seroconversion in acute exacerbation of patients with HBeAg-positive chronic hepatitis B

BACKGROUND & AIMS

This study aimed to identify the predictors for early hepatitis B e antigen (HBeAg) seroconversion following acute exacerbation (AE) in patients with HBeAg-positive chronic hepatitis B (CHB).

METHODS

A total of 151 patients with HBeAg-positive CHB and AE were consecutively enrolled. AE was defined as an elevation of alanine aminotransferase level to more than 5 times the upper limit of normal and more than twice the patients' baseline value. Early HBeAg seroconversion was defined as HBeAg loss and the appearance of hepatitis B e antibody within 6 months of AE. Clinical and laboratory data were compared between an early HBeAg seroconversion group and a nonearly HBeAg seroconversion group.

RESULTS

All patients had genotype C hepatitis B virus (HBV). Early HBeAg seroconversion occurred in 35.5% (39/110). Under univariate analysis, age, transmission mode, disease status, and serum HBV DNA level were associated with early HBeAg seroconversion. Multivariate analysis showed that nonvertical transmission mode (RR, 3.681; 95% CI, 1.279-10.592; P = .016) and low serum HBV DNA levels (< or = log [copies/mL]; RR, 6.891; 95% CI, 2.165-21.935; P = .001) were independent predictors.

CONCLUSIONS

Patients with CHB with genotype C may have a higher chance of early HBeAg seroconversion after AE in the context of nonvertical transmission and/or had low serum HBV DNA levels (< or = 7 log [copies/mL]) at AE. Therefore, we should take into account transmission modes and serum HBV DNA levels when choosing appropriate management strategies for patients who exhibit AE of HBeAg-positive CHB with genotype C.

The Molecular Diagnosis of Hepatitis B Virus-Associated Hepatocellular Carcinoma

Hepatitis B virus (HBV) infection is the major cause of hepatocellular carcinoma (HCC) worldwide. The pathogenesis of HBV-associated HCC has been studied extensively, and molecular changes during malignant transformation have been identified. It has been proposed that the insertion of HBV DNA into the human genome results in chromosomal instability and inactivation of tumor suppressor genes. Transactivation of oncogenes, inactivation of tumor suppressor genes, and alteration of the cell cycle by HBV proteins are also involved in the progression of hepatocellular carcinogenesis. Traditional clinical examinations of HCC, such as biopsy, computer tomography, ultrasonic imaging, and detection of such biomarkers as a-fetoprotein, are currently the "gold standard" in diagnosis. These tests diagnose HCC only in the late stages of disease. This limitation has greatly reduced the chance of survival of HCC patients. To resolve this problem, new biomarkers that can diagnose HCC in earlier stages are necessary. Based on recent molecular studies of the effects of HBV on cellular transformation, differentially expressed biomarkers of HBV infection have been elucidated. With the analyses of the HBV replication profile, the viral load (HBV DNA levels) of patients, and the viral protein expression, the severity of hepatitis in the preneoplastic stages can be assessed. In the future, with the molecular profiles identified by genomic and proteomic approaches, stage-specific biomarkers should be identified to monitor the progression and prognosis of HCC.

Clinical features and survival in Chinese patients with hepatitis B e antigen-negative hepatitis B virus-related cirrhosis

AIM

To compare the clinical features of hepatitis B e antigen (HBeAg)-negative and HBeAg-positive cirrhosis, and to define the survival and prognostic indicators of Chinese HBeAg-negative hepatitis B virus (HBV)-related cirrhosis.

METHODS

Two hundred and seventeen patients with chronic hepatitis B cirrhosis were studied. Survival was calculated using the Kaplan-Meier method. Proportional hazards Cox regression procedure was used to identify independent predictors of survival. The relationship between HBV-DNA viral load and prognosis was also investigated.

RESULTS

The mean follow-up time was 35 months (3-47 months). HBeAg-negative liver cirrhosis patients comprised the greatest number of cirrhosis patients. Median alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, median total leukocytes (WBC), hemoglobin (Hb), platelet (Plt) and HBV-DNA levels and the proportion of HBV-DNA > 10(5) copies/mL were lower in HBeAg-negative patients. There were fewer complications in patients treated with lamivudine than in other patients. Survival rates were significantly reduced in patients with HBeAg-negative cirrhosis (P = 0.0024). The baseline Child-Pugh scores and more than one decompensation during follow up were independent variables correlated with survival of HBeAg-negative liver cirrhosis patients (P = 0.006 and P = 0.001, respectively). The HBV-DNA viral load did not correlate with any complications or mortality rates of HBeAg-negative patients.

CONCLUSIONS

The clinical features of HBeAg-negative and -positive liver cirrhosis differ. Survival was significantly reduced for Chinese patients with HBeAg-negative than -positive cirrhosis. Factors contributing to the prognosis were baseline Child-Pugh scores and the presence of more than one decompensation during follow up.

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

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

CONCLUSION

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

Natural history of hepatitis B virus infection: an update for clinicians

Hepatitis B virus (HBV) is a common viral pathogen that causes a substantial health burden worldwide. Significant progress has been made in the past few decades in understanding the natural history of HBV infection. A dynamic balance between viral replication and host immune response is pivotal to the pathogenesis of liver disease. In immunocompetent adults, most HBV infections spontaneously resolve, whereas in most neonates and infants they become chronic. Those with chronic HBV may present in 1 of 4 phases of infection: (1) in a state of immune tolerance, (2) with hepatitis B e antigen (HBeAg)positive chronic hepatitis, (3) as an inactive hepatitis B surface antigen carrier, or (4) with HBeAg-negative chronic hepatitis. Of these, HBeAg-positive and HBeAg-negative chronic hepatitis may progress to cirrhosis and its long-term sequelae including hepatic decompensation and hepatocellular carcinoma. Several prognostic factors, such as serum HBV DNA concentrations, HBeAg status, serum aminotransferases, and certain HBV genotypes, have been identified to predict long-term outcome. These data emphasize the importance of monitoring all patients with chronic HBV infection to identify candidates for and select optimal timing of antiviral treatment, to recognize those at risk of complications, and to implement surveillance for early detection of hepatocellular carcinoma.

SPP1 polymorphisms associated with HBV clearance and HCC occurrence

BACKGROUND

Secreted phosphoprotein-1 (SPP1) is a secreted arginine-glycine-aspartate (RGD)-containing phosphoprotein. SPP1 is overexpressed in metastatic hepatocellular carcinoma (HCC), and therefore could act as both a diagnostic marker and a potential therapeutic target for metastatic HCC. We investigated the genetic polymorphisms in SPP1 to determine whether it is a potential candidate gene for a host genetic study of hepatitis B virus (HBV) clearance and HCC occurrence.

METHODS

Five genetic variants in SPP1 were genotyped by TaqMan assay and the genetic association with HBV clearance and HCC occurrence was analysed.

RESULTS

Genetic association analysis of SPP1 polymorphisms with an HBV cohort (n = 1,069) from the Korean population revealed that the most common haplotype (SPP1-ht2 [T-T-C-T-A]) was associated with HBV clearance. The frequency of the SPP1-ht2-bearing genotype in the chronic carrier (CC) group was higher than in the spontaneously recovered (SR) group (OR = 1.44 [95% CI 1.11-1.87], P = 0.006, P(corr) = 0.02). By Cox relative hazard analysis, both SPP1-ht2 and -1,800G > T were associated with age of HCC occurrence among chronic hepatitis patients, e.g. ht2/h2- and 1800T/T-bearing patients showed earlier progression to HCC than did others (RH = 1.85, P = 0.004, P(corr) = 0.01 and RH = 1.85, P = 0.003, P(corr) = 0.01, respectively).

CONCLUSION

Our findings suggest that SPP1 polymorphisms might be among the genetic factors for HBV clearance and/or HCC occurrence.

Management of hepatitis B: summary of a clinical research workshop

Chronic hepatitis B is caused by persistent infection with the hepatitis B virus (HBV), a unique DNA virus that replicates through an RNA intermediate produced from a stable covalently closed circular DNA molecule. Viral persistence appears to be due to inadequate innate and adaptive immune responses. Chronic infection has a variable course after several decades resulting in cirrhosis in up to one-third of patients and liver cancer in a proportion of those with cirrhosis. Sensitive assays for HBV DNA levels in serum have been developed that provide important insights into pathogenesis and natural history. Therapy of hepatitis B is evolving. Peginterferon induces long-term remissions in disease in one-third of patients with typical hepatitis B e antigen (HBeAg) positive chronic hepatitis B, but a lesser proportion of those without HBeAg. Several oral nucleoside analogues with activity against HBV have been shown to be effective in suppressing viral levels and improving biochemical and histological features of disease in a high proportion of patients with and without HBeAg, at least in the short term. What is uncertain is which agent or combination of agents is most effective, how long therapy should last, and which criteria should be used to start, continue, switch or stop therapy. Long-term therapy with nucleoside analogues may be the most appropriate approach to treatment, but the expense and lack of data on long-term safety and efficacy make recommendations difficult. Clearly, many basic and clinical research challenges remain in defining optimal means of management of chronic hepatitis B.

A 13-year longitudinal study of the impact of double mutations in the core promoter region of hepatitis B virus on HBeAg seroconversion and disease progression in patients with genotype C chronic active hepatitis

The pathogenic role of core promoter (CP) mutations (T1762/A1764) of hepatitis B virus (HBV) in hepatitis B e antigen (HBeAg) seroconversion or disease progression remains unclear. We investigated the clinical relevance of these mutants over a long-term follow-up period of up to 15 years. In this longitudinal cohort study, 29 HBeAg-positive patients with biopsy-proved chronic active hepatitis without cirrhosis were regularly monitored for >10 years. The viral isolates were characterized, using the frozen liver tissue obtained on the day of biopsy. Long-term outcomes were compared between patients with and without CP mutations of HBV at baseline. HBV genotyping showed that 100% of study subjects were infected with genotype C HBV. During a median follow-up period of 12.5 years, patients without double CP mutations of HBV at baseline showed a tendency towards achieving an earlier HBeAg seroconversion than those with (6.9 vs 9.4 years, P = 0.062) double CP mutations. Double CP mutations at baseline were also significantly associated with the eventual development of cirrhosis or hepatocellular carcinoma (P = 0.013), whereas the absence of double CP mutations predicted inactive carrier status at the last follow-up (P = 0.027). At 10 years, liver-related tests were also significantly better in patients without double CP mutations of HBV than in those with these mutations, as reflected by higher platelet counts and albumin levels (P = 0.036 and P = 0.044, respectively). Double T1762/A1764 mutations are significantly related to liver deterioration in HBeAg-positive genotype C active hepatitis patients. A longer period of immune clearance coupled with delayed HBeAg seroconversion appears to contribute to disease progression in patients harbouring these mutations in the CP region of HBV.

Natural course, therapeutic options and economic evaluation of therapies for chronic hepatitis B

Chronic hepatitis B virus infection afflicts 400 million people worldwide and untreated will progress to cirrhosis in 15-40% of individuals, with an associated increased risk for the development of hepatocellular carcinoma. The 'inactive carrier state' carries a benign prognosis with a very low risk of cirrhosis or hepatocellular carcinoma. However, the hepatitis B e antigen (HBeAg)-positive chronic hepatitis state is an active disease state with increased risk for progressing to cirrhosis and hepatocellular carcinoma. The HBeAg-negative mutant variety of chronic hepatitis B has been associated with a higher incidence of cirrhosis at initial presentation and more frequent progression to hepatocellular carcinoma compared with the wild-type hepatitis B. Five medications are currently approved by the US FDA for the treatment of chronic hepatitis B: interferon-alpha, lamivudine, adefovir dipivoxil, entecavir and peginterferon-alpha-2a. Interferon-alpha therapy has been shown to increase the rate of HBeAg and hepatitis B DNA loss with a small chance of hepatitis B surface antigen loss, but has significant adverse effects and is ineffective against the HBeAg-negative mutant. Lamivudine is a safely used, orally administered drug with good efficacy, but is associated with the development of a lamivudine-resistant (Lam-R) mutant in a large proportion of patients after long-term therapy. High relapse rates after lamivudine therapy make this medication less effective in the HBeAg-negative mutant also. Adefovir dipivoxil is a safely used, orally administered drug, which is effective against the Lam-R mutant. Adefovir dipivoxil is effective against the wild-type and HBeAg-negative hepatitis B and has a very low incidence of resistance development. Entecavir is a highly potent and selective new oral drug against hepatitis B. It has demonstrated no resistance development in treatment-naive patients, but a low incidence of resistance in patients infected with prior Lam-R mutants. Peginterferon-alpha-2a is administered once weekly and has improved efficacy compared with standard interferon-alpha and lamivudine. However, it has a similar adverse-effect profile to standard interferon-alpha. Pharmacoeconomic studies have demonstrated a cost benefit in treating chronic hepatitis B patients compared with no therapy. However, results have been conflicting, with earlier studies showing a cost advantage of lamivudine over interferon-alpha and a more recent, comprehensive study favouring interferon-alpha monotherapy in HBeAg-negative patients and adefovir dipivoxil 'salvage' after lamivudine resistance development in HBeAg-positive patients.

Long-term outcome of HBV carriers with negative HBe antigen and normal aminotransferase

PURPOSES

To elucidate the incidence of hepatitis activation and hepatocellular carcinogenesis in patients with negative HBe antigen and normal aminotransferase, long-term observation was performed in a retrospective cohort.

METHODS

Among 116 consecutive patients with normal aminotransferase and negative HBe antigen at the time of liver biopsy, sequential frozen sera for initial 5 years were available for 95 patients. Hepatitis B virus (HBV) DNA assay (sensitivity >400 copy/mL) and aminotransferase were annually examined in the initial 5 years after biopsy.

RESULTS

Liver biopsy showed minimal hepatitis (F0) in 9, F1 in 53, F2 in 21, F3 in 6, and F4 or cirrhosis in 6. Initial HBV DNA concentration was low (less than 10(4) copies/mL) in 33, intermediate (10(4)-10(6)) in 53, and high (10(6) or more) in 9. Hepatitis activation rates with twice as high as normal aminotransferase at the end of the third year were 12.1% in the low DNA group, 43.4% in the intermediate group, and 66.7% in the high DNA group. Initial HBV DNA values were significantly associated with future increase in aminotransferase (P <.0001). Initial DNA, history of aminotransferase elevation, and histological staging independently affected future hepatitis activation. Carcinogenesis rate in patients with and without high DNA of 10(6) copies/mL during the initial 3 years were 6.9% and 0%, respectively, at the end of the 5th year, and 11.5% and 1.8%, respectively, at the 10th year, (P=.021).

CONCLUSION

Advanced stages of hepatitis were sometimes found in HBe antigen-negative, aminotransferase-normal HBV carriers. Serial HBV DNA assessment in early 3 years predicted future hepatitis activation and carcinogenesis.

Viral factors correlate with hepatitis B e antigen seroconverson in patients with chronic hepatitis B

BACKGROUND/AIMS

Seroconversion (SC) from hepatitis B envelope antigen (HBeAg) to anti-HBe usually indicates lower viral loads, resolved hepatitis activity and improved long-term outcomes. However, the role of viral factors in the development of SC remains largely unknown. We thus comprehensively studied these factors in 25 patients with sustained HBeAg SC and seven control patients with sustained loss of HBeAg.

METHODS

We determined viral factors in serum samples obtained 1 year before, 6 months before, 3 months before, at the time of, 6 months after and 1 year after HBeAg SC or HBeAg loss. Precore A1896 and basal core promoter T1762/A1764 mutants were determined by polymerase chain reaction (PCR)-based assays. Serum HBV levels were determined by a real-time PCR assay.

RESULTS

We found that decline of serum viral load, frequently accompanied by hepatitis exacerbation, occurred within 1 year before HBeAg SC. The proportions of precore and BCP mutations also increased gradually throughout the process of HBeAg SC. The virologic features were similar between HBeAg SC group and HBeAg loss group. Before HBeAg SC or loss, genotype B patients had higher serum viral loads and lower proportions of BCP mutation compared with genotype C patients.

CONCLUSION

Our findings suggested that viral factors correlate with the development of sustained HBeAg SC or loss.

Human hepatitis B viral e antigen interacts with cellular interleukin-1 receptor accessory protein and triggers interleukin-1 response

Human hepatitis B virus (HBV) can cause acute and chronic hepatitis, cirrhosis, and hepatocellular carcinoma. HBV e antigen (HBeAg), a secreted protein and not required for viral replication, is thought to play an immunoregulatory role during viral infection. However, the functional involvement of HBeAg in host immune response has not been fully elucidated. We report in this study that HBeAg can bind to interleukin-1 receptor accessory protein (IL-1RAcP). Interleukin-1 (IL-1) plays an important role in inflammation and regulation of immune response, and membrane form of IL-1RAcP (mIL-1RAcP) is an essential component of trimeric IL-1/IL-1 receptor/mIL-1RAcP complex. We show that glutathione S-transferase- or polyhistidine-tagged recombinant HBeAg can interact with endogenous mIL-1RAcP in vitro. Purified (His)6-HBeAg added in the culture medium can interact with overexpressed FLAG-tagged mIL-1RAcP in vivo. Indirect immunofluorescence and confocal microscopy show that HBeAg colocalizes with mIL-1RAcP on the cell surface. Furthermore, HBeAg is able to induce the interaction of IL-1 receptor I (IL-1RI) with mIL-1RAcP and trigger the recruitment of adaptor protein myeloid differentiation factor 88 (MyD88) to the IL-1RI/mIL-1RAcP complex. Assembly and activation of IL-1RI/mIL-1RAcP signaling complex by HBeAg can activate downstream NF-kappaB pathway through IkappaB degradation, induce NF-kappaB-dependent luciferase expression, and induce the expression of IL-1-responsive genes. Silencing of IL-1RAcP by small interfering RNA dramatically abolishes HBeAg-mediated NF-kappaB activation. These results demonstrate that HBeAg can trigger host IL-1 response by binding to mIL-1RAcP. The interaction of HBeAg with mIL-1RAcP may play an important role in modulating host immune response in acute and chronic HBV infection.

Clinical Significance of the Genotype and Core Promoter/Pre-Core Mutations in Hepatitis B Virus Carriers

It has been shown that clinical and virological characteristics vary among hepatitis B virus (HBV) genotypes. In this study, we measured the virus level, disease severity, and presence or absence of core promoter (CP)/pre-core (PC) mutations in 241 HBV carriers, and investigated the clinical significance of measuring the HBV genotype. In genotype C HBV carriers, the proportion of hepatitis B e antigen (HBeAg)-positive patients was significantly higher than that in genotype B HBV carriers (0 vs. 34.4%, p < 0.05), and the virus level was higher (4.9 vs. 4.05 LGE/ml). In the genotype B HBV carriers, the incidence of PC mutation was significantly higher (69 vs. 34%, p < 0.05). In the genotype C HBV carriers, the incidence of CP mutation was significantly higher (13 vs. 78%, p < 0.05). We compared patients with the wild (W)/mutant (M) pattern in the CP/PC regions to those with the M/W pattern in the CP/PC regions among the genotype C HBV carriers. Both the proportion of HBeAg-positive patients (65.8 vs. 15.4%, p < 0.05) and the alanine aminotransferase (ALT) level (48 vs. 21.5 IU, p < 0.05) were higher in the patients with the M/W pattern in the CP/PC regions, and the disease severity was deteriorated. In conclusion, genotype B HBV may more frequently induce HBe seroconversion via PC mutation compared to genotype C HBV. Among the genotype C HBV carriers, hepatitis activity and the deterioration of the disease severity were significantly inhibited in the group in which PC mutation initially occurred, in comparison to the group in which CP mutation initially occurred.

The clinical virology of hepatitis B

Hepatitis B virus (HBV) is a major human health problem as approximately 8% of the world’s population are chronic carriers and there are over a million HBV-related deaths annually. Treatment of HBV is extremely difficult, as the unique viral replication strategy results in both a continual source of stable DNA molecules that are the template for viral replication and gene expression, and a pool of viral quasispecies from which different isolates may emerge as selection pressures alter. Although the use of antiviral therapies has improved outcomes significantly for many chronically infected individuals, the emergence of drug-resistant and immune/vaccine-escape viruses ensures there is a continuing need for the development of new and imaginative approaches to control and eventually eradicate HBV.

[Natural history of hepatitis B infection]

Hepatitis B virus (HBV) is transmitted by parenteral, sexual and perinatal routes. While fulminant hepatitis may occur in 1% of cases of symptomatic acute hepatitis, the principal problem of HBV infection is that it may become chronic, classically defined by carriage of HB surface antigens (HBsAg) for more than 6 months. This occurs in only 0.5 to 3% of immunocompetent adults but more frequently in children (up to 90%) and in immune-compromised patients (30 to 100%). The course of chronic HBV infection is characterized by variations in viral replication with spontaneous reactivation or discontinuation, and potential exacerbations observed clinically or by laboratory testing. The pathogenesis of HBV infection is mainly immune-mediated, resulting from host-virus interactions but also from the complexity of the virus itself (integration, mutation, occult replication). These factors explain the variety of presentations of chronic HBV infection, which range from immune tolerance to inactive carriage of HBsAg, passing through a stage of immune clearance, where chronic active hepatitis which may lead to cirrhosis (yearly incidence of 1.3 to 5.9%). Cirrhosis may be complicated by portal hypertension, liver failure, or hepatocellular carcinoma, which together explain 80% of the morbidity and mortality associated with HBV. The 5-year survival rate for HBV-related cirrhosis ranges from 52 to 82%. Immunosuppression, hepatitis D virus superinfection, and chronic alcohol consumption are the principal factors that modify this natural history. Chronic HBV infection is a major public health problem, particularly in developing countries, and it requires that efforts to make HBV vaccination universal be intensified.

Assessment and Management of Chronic Hepatitis B

An understanding of the natural history of CHB is critical for the management of the liver disease. Three clinical patterns with different clinical outcomes are recognized: HBeAg-positive CHB, HBeAg-negative CHB,and inactive CHB. Patients with elevated aminotransferase levels and HBV DNA greater than 105 viral copies per mL in serum and with features of chronic hepatitis on liver biopsy are candidates for therapy regardless of HBeAg status. Multiple host and viral factors and safety profiles of current therapies need to be considered carefully before recommending therapy. There appears to be no role for HBV genotyping in the management of patients. Three antiviral agents are approved for use against CHB infection:IFN-a, lamivudine, and adefovir. Efficacy is moderate at best and is limited by the poor tolerability of IFN and the development of resistance, coupled with concerns regarding the long-term safety with nucleoside analogs. Several new nucleoside and nucleotide analogs and novel agents are at various stages of development as potential therapies for CHB. The ideal compound would be one that is active against all replicative intermediates of the virus and has a low toxicity profile. Despite current shortcomings, the future of therapy for HBV is promising, as newer therapeutic options are being developed based on an understanding of the HBV life cycle.

Natural history of chronic hepatitis B virus infection: what we knew in 1981 and what we know in 2005

Remarkable progress has been made in our understanding of the natural history of chronic hepatitis B virus (HBV) infection in the past 25 years. Availability of sensitive HBV DNA assays and application of sophisticated immunological techniques led to the recognition that HBV replication persists throughout the course of chronic HBV infection, and host immune response plays a pivotal role in HBV-related liver disease. Knowledge of the HBV genome organization and replication cycle led to the unraveling of HBV genotypes and molecular variants, which contribute to the heterogeneity in outcome of chronic HBV infection. The natural course of chronic HBV infection is now perceived as consisting of 4 phases: immune tolerance, immune clearance [hepatitis B e antigen (HBeAg)-positive chronic hepatitis], inactive carrier state, and reactivation (HBeAg-negative chronic hepatitis B). Understanding the dynamic nature of chronic HBV infection is crucial in the management of HBV carriers and underscores the need for long-term monitoring. Accumulating evidence indicates that antiviral therapy can prevent progression of HBV-related liver disease, particularly among patients with sustained response. Newer antiviral therapies with improved efficacy and decreased risk of resistance may lead to a complete revision of the chapter on the natural history of chronic HBV infection on the occasion of the golden jubilee of Hepatology.

Relative predictive factors for hepatocellular carcinoma after HBeAg seroconversion in HBV infection

AIM: To determine the predictive factors for hepatocellular carcinoma (HCC) development in patients after spontaneous or therapeutic HBeAg seroconversion.

METHODS: In 48 patients who seroconverted to anti-HBe positive during follow-up, the background factors for HCC development were analyzed.

RESULTS: HCC was developed in six patients during follow-up (average follow-up after HBeAg seroconversion: 10.9±5.4 years). The incidence of HCC evaluated by Kaplan–Meier analysis was significantly higher in patients with abnormal aspartate aminotransferase (AST> 40 IU/L) level, lower platelet counts (PLT<10×10⁴/µL), lower albumin level (Alb<30 g/L), positive HBV-DNA or older age at seroconversion (>40 years). However, lower platelet count was the only predictive factor for HCC development shown by multivariate proportional-hazard analysis.

CONCLUSION: Active hepatitis or advanced hepatitis at HBeAg seroconversion or progressive hepatitis even after HBeAg seroconversion would be the risk factors for HCC development. These predictive factors should be taken into account in determining the frequency of biochemical study or imaging studies for HCC surveillance.

T1764G1766 core promoter double mutants are restricted to Hepatitis B virus strains with an A1757 and are common in genotype D

To investigate the role of pre-core and basal core promoter (BCP) mutants in hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (e-CHB) in Iran, Hepatitis B virus strains from 30 patients and 42 anti-HBe-positive asymptomatic carriers (ASCs) were characterized. G1896A pre-core stop mutants, detected in 77 % of e-CHB patients and 85 % of ASCs, showed no association with virus load or aminotransferase levels. Twenty per cent of e-CHB patients and 31 % of ASCs harboured T1762A1764 mutants. When this double mutation was associated with G1757, it was linked to a higher virus load in patients than when it was associated with A1757 (10(5.2+/-1.8) vs 10(3.2+/-0.8) copies ml(-1); P=0.004). Interestingly, the most common BCP mutations were T1764 and G1766, which were present in 33 % of e-CHB patients and 29 % of ASCs. These were associated with higher virus load and aminotransferase levels compared with patients lacking core promoter mutations, although this was not significant. The T1764G1766 double mutation was only present in strains with A1757 (P<0.001), which is more frequent in strains of genotype D than in those belonging to other genotypes. On the other hand, the T1762A1764 double mutation was found more frequently in association with G1757 than with A1757. The T1762A1764 double mutation forms a binding site for hepatocyte nuclear factor 1 (HNF1), which is constrained by A1757. However, the T1764G1766 double mutant may form a binding site for HNF3. Thus, position 1757 affects the emergence of promoter double mutants and would predict a relative genotypic restriction of both the T1762A1764 and the T1764G1766 double mutants.

High frequency of the 1896 precore mutation in patients and blood donors with hepatitis B virus infection from the Indian subcontinent

AIM

Hepatitis B virus (HBV) e antigen (HBeAg)-negative variants are reported to harbor 1896 precore mutants, and predict a worse clinical outcome. The aim of this study was to estimate the incidence of a precore mutation (1896) in both patients with chronic hepatitis B (CH-B) infection and blood donors in a tertiary care hospital in south India.

METHODS

One hundred and twenty-two consecutive HBV DNA-positive CH-B patients (group I) and 102 HBsAg-positive 'healthy' blood donors (group II) were recruited. Samples found to be positive for HBV DNA were further studied. A nested PCR was used for the detection of HBV DNA. The 1896 precore mutation was detected using PCR-restriction fragment length polymorphism (RFLP). Nucleotide sequencing was performed on representative samples to confirm PCR-RFLP findings. The study population was stratified comprising: group IA: 17 HBeAg-positive CH-B patients; group IB: 105 HBeAg-negative CH-B patients; group IIA: 12 HBeAg-positive blood donors; and group IIB: 55 HBeAg-negative blood donors.

RESULTS

There was no significant difference in the HBeAg-positive status between groups I and II. Significantly higher levels of alanine transaminase (ALT) were seen in groups IA and IB than in groups IIA and IIB, respectively (p = 0.033; p = 0.004). A significantly higher proportion of CH-B patients (32.7%) were positive for anti-HBc IgM compared with the blood donor groups (10.4%; p = 0.0006). Among the HBeAg-negative subjects, 69% of the CH-B patients and 65% of the blood donors showed evidence of 1896 precore mutant. This infection included the 1896 mutant exclusively or mixed infection involving the 1896 mutant and 1896 wild-type.

DISCUSSION

The absence of detectable HBeAg in most of the viremic blood donors and patients emphasizes the need for HBV DNA testing irrespective of HBeAg status. Mixed infection was detected in a higher proportion (42.6%) of CH-B patients than in blood donors (26.8%; p = 0.031). Among those with mixed infection, a significant proportion (44.2%) of CH-B patients, had ALT levels greater than the upper limit of normal (ULN), as compared with the blood donor groups (16.6%; p = 0.036).

CONCLUSIONS

The majority of CH-B patients and blood donors were negative for HBeAg despite their positive HIV DNA status. About two-thirds of the HBsAg-positive blood donors were viremic. Mixed infection was detected more frequently in CH-B patients and appears to be associated with more pronounced liver damage, as indicated by increased ALT levels.

Patients with and without loss of hepatitis B virus DNA after hepatitis B e antigen seroconversion have different virological characteristics

The characteristic differences between patients with and without loss of hepatitis B virus (HBV) DNA after achieving hepatitis B e antigen seroconversion were analyzed by comparing changes in HBV DNA and HBV core-related antigen levels during a period from 3 years before to 3 years after the seroconversion. Of the 24 seroconverters, 6 (inactive replication group) showed continuous loss of HBV DNA in serum after the seroconversion and the remaining 18 did not lose HBV DNA (active replication group). The HBV DNA level was similar between the two groups, while the HBV core-related antigen level was significantly lower in the active replication group than in the inactive replication group before the seroconversion. The levels of both HBV DNA and HBV core-related antigen decreased remarkably around the time of seroconversion in the inactive replication group, while these levels did not change or decreased slightly in the active replication group. After the seroconversion, the HBV DNA level was significantly higher in the active replication group than in the inactive replication group, while the HBV core-related antigen level was similarly low between the two groups. Because the serum level of HBV core-related antigen mainly reflects that of HBe antigen, the low level of HBV core-related antigen seen after seroconversion in both groups might have contributed to the occurrence of seroconversion. The precore and core promoter mutations which cause diminished excretion of hepatitis B e antigen were significantly more frequent in the active replication group than in the inactive replication group. It was therefore considered that the seroconversion was caused mainly by a decrease in viral replication in the inactive replication group, and mainly by a decrease in HBe antigen production in the active replication group.

Histopathology and clinical correlates of end-stage hepatitis B cirrhosis: a possible mechanism to explain the response to antiviral therapy

In chronic liver disease associated with histological necroinflammation, clinical severity is frequently greater in those with higher grades of activity. Conventional wisdom assumes that necroinflammation is mild or absent in patients with end-stage hepatitis B virus (HBV) cirrhosis due to the frequent presence of mildly elevated aminotransferase levels, the absence of hepatitis B e antigen (HBeAg), and low or undetectable HBV deoxyribonucleic acid (DNA) levels. However, a histopathologic analysis of such patients has not been undertaken. The aims of this study were 1) to assess severity and histological features of inflammation, 2) to correlate the severity of inflammation with biochemical and virologic parameters, and 3) to define the relationship between inflammation and clinical severity in explanted livers from patients undergoing liver transplantation for HBV cirrhosis. Characteristics of 34 consecutive patients undergoing liver transplantation for HBV cirrhosis were correlated with inflammation and immunohistological findings in the explanted livers. High-grade inflammation (grades 3 and 4) was found in many cases (47.1% interface hepatitis; 14.8% lobular inflammation; and 20.6% portal inflammation). The presence of positive cytoplasmic staining for hepatitis B core antigen (HBcAg) was associated with grade 3 or 4 interface hepatitis (P = .046) and lobular hepatitis (P = .005). There was no correlation between inflammatory activity and age, Asian ethnicity, aminotransferase levels, total bilirubin levels, HBeAg seropositivity, and detectable HBV DNA level. Patients with high-grade inflammation had greater degrees of hepatic decompensation. In conclusion, high-grade inflammation is common in end-stage HBV cirrhosis, but it is not readily detected by biochemical and virologic parameters. High-grade inflammation is associated with a greater degree of hepatic decompensation.

Management of chronic hepatitis B

Chronic hepatitis B (CHB) is a major worldwide cause of chronic liver disease and a significant public health issue. Three predominant clinical presentations are recognized: hepatitis B e antigen(HBeAg) or typical CHB, HBeAg-negative or atypical CHB, and inactive CHB. The natural history of CHB infection in an individual may be dominated by one or a combination of these clinical presentations in a sequential fashion. These variations in clinical presentations reflect the viral-host immunology dynamics that form the basis for the development of liver disease. Therapy has been problematic in the past. There are three licensed drugs available for therapy of CHB with varied mechanisms of action. This has introduced the concept of tailored therapy for the individual patient. Many promising new agents and therapeutic approaches should become available in the near future.

Natural history of hepatitis B e antigen to antibody seroconversion in patients with normal serum aminotransferase levels

BACKGROUND

Natural history studies of hepatitis B virus infection have shown relapse of hepatitis in 5% to 15% of patients and progression to cirrhosis in 2% to 6% annually. Follow-up of patients beginning at the early phase of infection might provide data with less referral bias than in previous studies.

METHODS

Test of liver biochemistry, assessment of virological markers, and ultrasound examinations were performed at regular intervals during the course of hepatitis B e antigen (HBeAg) to antibody (anti-HBe) seroconversion in 240 HBeAg carriers with normal alanine aminotransferase levels at baseline. Factors predictive of cirrhosis were identified by multivariate analysis.

RESULTS

We enrolled 130 men and 110 women. The mean (+/- SD) age at entry was 27.6 +/- 6.2 years. During the HBeAg-positive phase, 29% of patients had alanine aminotransferase levels > or =200 U/L, 3% had bilirubin levels > or =2.0 mg/dL, and 5% had two or more episodes of alanine aminotransferase levels > or =200 U/L. The mean age at anti-HBe seroconversion was 31.3 +/- 7.0 years, with remission of hepatitis in all patients. However, hepatitis recurred in 36 patients (15%), with an annual rate of 2.2%. Thirteen patients (5%) progressed to cirrhosis. The annual incidence of cirrhosis was 0.5%, and the cumulative probability of cirrhosis after 17 years was 12.6%. Age at anti-HBe seroconversion and relapse of hepatitis were independent risk factors for cirrhosis.

CONCLUSION

The clinical severity of chronic hepatitis B was milder in this cohort than in previous studies. Delayed HBeAg seroconversion and relapse of hepatitis were associated with increased risk of cirrhosis.

High viral load is a risk factor for hepatocellular carcinoma in patients with chronic hepatitis B virus infection

BACKGROUND AND AIMS

Hepatitis B virus (HBV) is considered a major risk factor for the progression to liver cirrhosis and hepatocellular carcinoma (HCC). The serum level of HBV-DNA is correlated with progression of the disease. The aim of the present study was to determine the relationship between the level of HBV-DNA and hepatocarcinogenesis in patients with chronic HBV infection.

METHODS

The authors studied 73 patients who were diagnosed with chronic HBV infection at Nagasaki University Hospital (Nagasaki, Japan) between January 1980 and December 1999. The significance of age, sex, habitual drinking, serum alanine aminotransferase level, HBV viral load, interferon treatment, hepatic fibrosis and hepatic inflammation on the development of HCC were examined using univariate and multivariate analyses.

RESULTS

The cumulative incidence rates of HCC were 14%, 29% and 48% at 5, 10 and 15 years after liver biopsy, respectively. Multivariate analysis identified high viral load, together with age and severe fibrosis, as independent and significant risk factors (P = 0.045, 0.047 and 0.013, respectively) for HCC.

CONCLUSIONS

The present findings indicate that high viral load is a risk factor for HCC in patients with chronic HBV infection. Patients with a high HBV viral load should be carefully monitored for HCC.

Double point mutation in the core promoter region of hepatitis B virus (HBV) genotype C may be related to liver deterioration in patients with chronic HBV infection

BACKGROUND AND AIM

Hepatitis B virus (HBV) genotype C has a more severe pathogenesis than genotype B in Japan. We retrospectively investigated the relationship between HBV genotype and the core promoter (CP) (nt 1762 and 1764) and precore (PreC) (nt 1896) mutations of the HBV genome.

METHODS

A total of 129 Japanese patients (42 genotype B and 87 genotype C) with chronic HBV infection, living in two different geographical areas in Japan, were evaluated (mean follow-up period 10.1 +/- 3.8 years). In 2000, CP and PreC HBV mutations were analyzed by direct sequencing from sera. Hepatitis B e antigen (HBeAg), HBV DNA and serial alanine aminotransferase (ALT) changes were followed and determined using serological methods.

RESULTS

Genotype C patients had significantly higher rates of HBeAg (40.2%vs 2.4%), HBV DNA positivity (75.9%vs 7.1%) and ALT abnormality (71.3%vs 11.9%) than genotype B patients (all P < 0.05). Among genotype B patients, CP wild type (92.9%) was predominant and PreC mutation (88.1%) was predominant. However, among genotype C patients, CP mutation (75.9%) was predominant and PreC mutation (66.7%) was predominant. The CP mutation was found significantly more in genotype C than in genotype B (P < 0.05). Of the 67 patients with ALT abnormality, five (7.5%) genotype B and 62 (92.5%) genotype C patients (31 HBeAg positive and 31 negative) were found. Among the 31 genotype C patients who were HBeAg positive, the combination of CP mutation and PreC wild (54.8%) was predominant, while among the remaining 31 genotype C patients who were HBeAg negative, the combination of CP mutation and PreC mutant (71.0%) was predominant.

CONCLUSION

Genotype C might be one of the worse prognostic markers in patients with chronic HBV infection, possibly because of mutation in the CP region.

Plasma pituitary adenylate cyclase activating polypeptide (PACAP) levels in chronic hepatitis B patients under lamivudine treatment

OBJECTIVE

Lamivudine is a nucleoside analogue with potent antiviral activity against hepatitis B virus (HBV). Plasma pituitary adenylate cyclase activating polypeptide (PACAP) is a multifunctional neuropeptide that is produced within the lymphoid microenvironment and induces the production of Th2-type cytokines. The aim of our study was to investigate the possible alterations of plasma PACAP-38 levels in chronic hepatitis B (CHB) patients during lamivudine treatment and to compare them with biochemical, virological and histological data.

METHODS

Plasma PACAP-38 levels were measured using competitive radio-immune analysis (RIA) in 25 CHB patients before and after completion of a 52-week lamivudine treatment period and in 22 healthy blood donors. Biochemical evaluation was done at baseline and every three months during treatment. Virological evaluation (HBV-DNA) was performed at baseline and at weeks 24 and 52 of treatment. Baseline liver histology was assessed for all patients at the beginning and at week 52 of the study for histological comparison with the pretreatment biopsy, according to the Ishak scoring system. Statistical evaluation of data was done using analysis of variance and Student's t-test.

RESULTS

Virological breakthrough was observed in seven (28%) patients at week 52 of treatment. Histological improvement was observed in 21 (84%) CHB patients, despite the emergence of tyrosine-methionine-aspartate-aspartate (YMDD) mutations. Plasma PACAP-38 levels were significantly lower in CHB patients at baseline than in healthy blood donors. Significant elevation of plasma peptide levels was observed in CHB patients after the completion of lamivudine treatment period, even in the subgroup of those who exhibited YMDD variants.

CONCLUSION

The elevation of plasma PACAP-38 levels in treated CHB patients following lamivudine-induced elimination of viraemia suggests a possible alteration of T-cellular immune response, resulting in biochemical and histological remission of liver disease, even in patients who exhibited virological breakthrough.