Recent advances in the treatment of chronic hepatitis B

Advanced siRNA delivery in combating hepatitis B virus: mechanistic insights and recent updates

Hepatitis B virus (HBV) infection is a major health problem, causing thousands of deaths each year worldwide. Although current medications can often inhibit viral replication and reduce the risk of liver carcinoma, several obstacles still hinder their effectiveness. These include viral resistance, prolonged treatment duration, and low efficacy in clearing viral antigens. To address these challenges in current HBV treatment, numerous approaches have been developed with remarkable success. Among these strategies, small-interfering RNA (siRNA) stands out as one of the most promising therapies for hepatitis B. However, naked siRNAs are vulnerable to enzymatic digestion, easily eliminated by renal filtration, and unable to cross the cell membrane due to their large, anionic structure. Therefore, effective delivery systems are required to protect siRNAs and maintain their functionality. In this review, we have discussed the promises of siRNA therapy in treating HBV, milestones in their delivery systems, and products that have entered clinical trials. Finally, we have outlined the future perspectives of siRNA-based therapy for HBV treatment.

Exploring evidence-based innovative therapy for the treatment of chronic HBV infection: experimental and clinical

With the advent of various vaccines and antimicrobial agents during the 20th century, the control and containment of infectious diseases appeared to be a matter of time. However, studies unveiled the diverse natures of microbes, their lifestyle, and pathogenetic potentials. Since the ground-breaking discovery of the hepatitis B virus (HBV) by Baruch Blumberg and the subsequent development of a vaccine in the early 1980s, the main task of the scientific community has been to develop a proper management strategy for HBV-induced chronic liver diseases. In the early 1980’s, standard interferon (IFN) induced a reduction of HBV DNA levels, followed by the normalization of serum transaminases (alanine aminotransferase, ALT), in some chronic hepatitis B (CHB) patients. However, in the course of time, the limitations of standard IFN became evident, and the search for an alternative began. In the late 1980’s, nucleoside analogs entered the arena of CHB treatment as oral drugs with potent antiviral capacities. At the beginning of the 21st century, insights were developed into the scope and limitations of standard IFN, pegylated-IFN as well as nucleoside analogs for treating CHB. Considering the non-cytopathic nature of the HBV, the presence of covalently closed circular DNA (cccDNA) in the nucleus of the infected hepatocytes and HBV-induced immune-mediated liver damages, a new field of CHB management was initiated by modulating the hosts’ immune system through immune therapy. This review will discuss the nature and design of innovative immune therapy for CHB.

Comparative role of tenofovir versus entecavir for treating patients with hepatitis B virus-related acute on chronic liver failure

INTRODUCTION

The aim of the study was to compare the safety and efficacy of tenofovir versus entecavir for treatment of naive acute on chronic liver failure (ACLF) due to hepatitis B virus (HBV) (ACLF-B).

METHODS

Thirty-two patients aged 14-65 years were enrolled in the study. Diagnosis of ACLF was confirmed by clinical condition, biochemical analysis, and virological data. The causes of both chronic liver damages and acute insult in all patients were HBV. They were expressing HBV DNA in the sera, positive for IgM anti-HBc, had increased levels of serum bilirubin, compromised prothrombin time; and more than 50% patients had encephalopathy. The standard dose of tenofovir and entecavir was given.

RESULTS

The antiviral effects of tenofovir and entecavir were evident as most patients became negative for HBV DNA in the sera after 90 days of therapy. Also, the levels of serum bilirubin, CTP (Child-Turcotte-Pugh) and MELD (model for end-stage liver disease) score exhibited significant improvement due to antiviral therapy. Although the improvement of liver functions, and liver damages were detected in patients receiving both tenofovir and entecavir, the survival of the patients was significantly higher in those receiving tenofovir compared to entecavir-treated patients.

CONCLUSION

This prospective study with limited number patients provides a challenge to assess the real potential of tenofovir over entecavir as therapeutic option for ACLF-B by conducting a multicenter clinical trial enrolling patient of different races and background.

MRI-Based Radiomics Models Developed With Features of the Whole Liver and Right Liver Lobe: Assessment of Hepatic Inflammatory Activity in Chronic Hepatic Disease

BACKGROUND

The noninvasive assessment of hepatic inflammatory activity (HIA) is crucial for making clinical decisions and monitoring therapeutic efficacy in chronic liver disease (CLD).

PURPOSE

To develop MRI-based radiomics models by extracting features from the whole liver and localized regions of the right liver lobe, compare the efficiency of two radiomics models, and further develop a radiomics nomogram for the assessment of HIA in CLD.

STUDY TYPE

Retrospective.

POPULATION

In all, 137 consecutive patients.

FIELD STRENGTH/SEQUENCE

1.5T/T2 -weighted imaging.

ASSESSMENT

All patients (nonsignificant HIA, n = 98; significant HIA, n = 39) were randomly divided into a training (n = 95) and a test cohort (n = 42). Radiomics features were extracted from the regions covering the whole liver (ROI-w) and localized regions of the right liver lobe (ROI-r). Least absolute shrinkage and selection operator (LASSO) and multivariate logistic regression analyses were used to select features and develop radiomics models. A combined model fusing the valuable radiomics features with clinical-radiological predictors was developed. Finally, a radiomics nomogram derived from the combined model was developed.

STATISTICAL TESTS

Synthetic minority oversampling technique algorithm, LASSO, receiver operator characteristic curve, and calibration curve analysis were performed.

RESULTS

The area under the curve (AUC), sensitivity, and specificity of the ROI-w radiomics model in assessing HIA were 0.858, 0.800, and 0.733, respectively. The ROI-r model were 0.844, 0.733, and 0.867, respectively. No differences were detected between the two radiomics models (P = 0.8329). The combined model fusing valuable ROI-w radiomics features, albumin, and periportal edema exhibited a promising performance (AUC, 0.911). The calibration curves showed good agreement between the actual observations and nomogram predictions.

DATA CONCLUSION

The MRI-based radiomics models had a powerful ability to evaluate HIA and the ROI-w radiomics model was comparable to the ROI-r model. Moreover, the radiomics nomogram could be a favorable method to individually estimate HIA in CLD. J. MAGN. RESON. IMAGING 2020;52:1668-1678.

Treatment of chronic hepatitis B naïve patients with a therapeutic vaccine containing HBs and HBc antigens (a randomized, open and treatment controlled phase III clinical trial)

Context

Current drugs for chronic hepatitis B therapy have a poor efficacy in terms of post-treatment sustained viral suppression and generate important side effects during and after therapy. Therapeutic vaccination with HBV antigens is an attractive alternative to test.

Objective

Evaluating the efficacy of a therapeutic vaccine candidate (designated NASVAC) containing both hepatitis B surface antigen (HBsAg) and core antigen (HBcAg) versus pegylated interferon (Peg-IFN) in naïve chronic hepatitis B patients.

Design, setting, participants

An open phase III, randomised and treatment controlled clinical trial was conducted in a total of 160 CHB patients, allocated into two groups of 80 patients each to receive NASVAC or Peg-IFN. The vaccine formulation comprised 100 μg of each HBsAg and HBcAg, and was administered in 2 cycles of 5 doses. The control group received 48 subcutaneous injections of Peg-IFN alfa 2b, 180 μg per dose, every week, for 48 consecutive weeks.

Main outcome measure

The primary outcome measure was in relation with the proportion of patients showing reduction of the viral load under the limit of detection (250 copies/mL) after 24 weeks of treatment completion.

Results

Sustained control of HBV DNA was significantly more common in NASVAC group (p<0.05) at 24 weeks of follow up. NASVAC-induced increases of alanine aminotransferases (ALT) were detected in 85% patients after 5 nasal vaccinations, although seen in only 30% of patients receiving Peg-IFN. At the end of treatment (EOT) antiviral effect was comparable in both NASVAC and Peg-IFN groups. Clearance of Hepatitis B e antigen (HBeAg) was also more frequent in NASVAC group compared to Peg-IFN recipients. A lower progression to cirrhosis was found in NASVAC group compared to Peg-IFN group.

Conclusion

Nasvac induced a superior reduction of the viral load under the limit of detection compared to Peg-IFN treatment. It is a safe and efficacious finite alternative of antiviral treatment for CHB patients.

Trial registration

ClinicalTrials.gov NCT 01374308.

Virological and Clinical Characteristics of Hepatitis B Virus Genotype A

Hepatitis B virus (HBV) infection is one of the most prevalent chronic viral infections in humans. The overall prevalence of hepatitis B surface antigen (HBsAg) is reported to be 3.6%; however, it varies depending upon the geographic area. HBV is classified into ten genotypes (A through J) on the basis of an intergroup genomic divergence of > 8%. Specifically, HBV genotype A exhibits several unique virological and clinical characteristics and can be further classified into seven subtypes. Among them, subtype A2 or Ae (A2/[e]) is occasionally responsible for nosocomial infection and among homosexual males. Regarding virological factors, the G1896A precore mutation is rarely observed in genotype A as it would disrupt an essential stem-loop structure in the ε signal essential for pregenomic RNA packaging. HBV genotype A also harbors a 6-nucleotide C-terminal insertion in the hepatitis B-e antigen (HBeAg) precursor, resulting in a variable-length HBeAg protein product observed in serum of positive patients. These molecular traits likely contribute to the specific clinical presentation of genotype A-infected patients, such as mild acute hepatitis B (AHB), longer persistence of HBsAg positivity in AHB, and increased chronicity after AHB in adults. However, genotype A shows a better response to interferon than other genotypes in chronic hepatitis B patients. Here, we review the virological and clinical characteristics of HBV genotype A that will be useful in elucidating the association among persistent viral infection, host genetic factors, and treatment in future studies.

Time-varying serum gradient of hepatitis B surface antigen predicts risk of relapses after off-NA therapy

Background

The serum gradient of hepatitis B surface antigen (HBsAg) varies over time after cessation of nucleos(t)ide analog (NA) treatment in patients with chronic hepatitis B (CHB). The association between the time-varying HBsAg serum gradient and risk of relapse has not been elucidated.

Methods

This multicenter cohort study prospectively enrolled CHB patients who discontinued 3 year-NA treatment. Eligible patients were serologically negative for HBeAg and viral DNA at NA cessation. The participants (n = 140) were followed every 3 months through HBsAg quantification. Virological and clinical relapses were defined as viral DNA levels >2000 IU/mL and alanine aminotransferase (ALT) levels >80 U/mL, respectively. The association of time-varying HBsAg levels with relapses was assessed through a time-dependent Cox analysis.

Results

During a median follow-up of 19.9 (interquartile range [IQR], 10.6–25.3) months, virological and clinical relapses occurred in 94 and 49 patients, with a 2-year cumulative incidence of 79.2% (95% confidence interval [CI], 70.9%–86.4%) and 42.9% (95% CI, 34.1%–52.8%), respectively. The serum level of HBsAg was associated with virological (P < 0.001) and clinical (P = 0.01) relapses in a dose–response manner, with adjusted hazard ratios of 2.10 (95% CI, 1.45–3.04) and 2.32 (95% CI, 1.28–4.21). Among the patients (n = 19) whose HBsAg levels ever dropped below 10 IU/mL, only one and three patients subsequently developed clinical and virological relapses.

Conclusion

The serum gradient of HBsAg measured throughout the off-therapy observation is associated with the subsequent occurrence of virological and clinical relapses in CHB patients who discontinue NA treatment.

Novel insights into immunotherapy for hepatitis B patients

The possible use of immunotherapy for hepatitis B has emerged for two major reasons: (1) chronic hepatitis B (CHB) is an immune-mediated pathological condition, and (2) commercially available antiviral drugs are of limited efficacy. Although various immunomodulatory agents have been used to treat patients with CHB during the last three decades, there is currently no consensus among physicians and hepatologists regarding the suitability of immunotherapy for patients with CHB. However, new insights into immunotherapy for CHB have emerged; these may facilitate design of effective and tolerable immunotherapy regimens for these patients. This review provides a comprehensive overview of immunotherapy for CHB.

Immune therapy for hepatitis B

Although several antiviral drugs are now available for treatment of patients with chronic hepatitis B (CHB), sustained off-treatment clinical responses and containment of CHB-related complications are not achieved in majority of CHB patients by antiviral therapy. In addition, use of these drugs is endowed with substantial long term risk of viral resistance and drug toxicity. The infinite treatment regimens of antiviral drugs for CHB patients are also costly and usually unbearable by most patients of developing and resource-constrained countries. Taken together, there is a pressing need to develop new and innovative therapeutic approaches for CHB patients. Immune therapy seems to be an alternate therapeutic approach for CHB patients because impaired or distorted or diminished immune responses have been detected in most of these patients. Also, investigators have shown that restoration or induction of proper types of immune responses may have therapeutic implications in CHB. Various immunomodulatory agents have been used to treat patients with CHB around the world and the outcomes of these clinical trials show that the properties of immune modulators and nature and designing of immune therapeutic regimens seem to be highly relevant in the context of treatment of CHB patients. In this review, the general properties and specific features of immune therapy for CHB have been discussed for developing the guidelines of effective regimens of immune therapy for CHB.

Hepatitis B vaccination and prevention of hepatocellular carcinoma

Hepatitis B virus (HBV) infection is a global health threat; with 240 million people are chronic carriers of the virus. The infection can cause acute and chronic liver disease including liver cirrhosis and hepatocellular carcinoma (HCC). On the basis of disease burden and the availability of safe and effective vaccines, World Health Organization has recommended that hepatitis B vaccine be incorporated into routine infant and childhood immunization programs for all countries. The efficacy of universal immunization has been proven in many countries, with substantial reductions of the prevalence of HBV carriage in children, adolescents and young adults. Most important, hepatitis B vaccination can protect them from HCC, as has been demonstrated in Taiwan and other countries. Nevertheless, the implementation of worldwide vaccination against HBV indeed requires more effort to overcome the social and economic challenges. To have a global control of HBV infection, we have to continue the universal HBV vaccination, interrupt the possible transmission routes and treat eligible patients with antiviral agents. However, current treatments are still far from ideal as they cannot eradicate intrahepatic HBV cccDNA, and lifelong administration of these agents will pose a major economic burden, especially in the endemic Asia-Pacific region. Thus we need innovative treatment strategies and novel agents with difference modes of action to overcome the unmet medical need for an efficient HBV cure with subsequent global eradication of HBV infection, hopefully by the first half of 21st century.

Comparative effectiveness of antiviral treatment for hepatitis B: a systematic review and Bayesian network meta-analysis

OBJECTIVE

A wide variety of competing drugs are available to patients for the treatment of chronic hepatitis B. We update a recent meta-analysis to include additional trial evidence with the aim of determining which treatment is the most effective.

METHODS

Twelve monotherapy or combination therapy were evaluated in treatment-naive individuals with hepatitis B e antigen (HBeAg) positive or negative patients. Databases were searched for randomized controlled trials in the first year of therapy. Bayesian random effects network meta-analysis was used to calculate the pairwise odds ratios, 95% credible intervals and ranking of six surrogate outcomes.

RESULTS

In total, 22 studies were identified (7508 patients): 12 studies analysed HBeAg-positive patients, six analysed HBeAg-negative patients, and four evaluated both. Tenofovir was most effective at increasing efficacy in HBeAg-positive patients, ranking first for three outcomes and increased odds of undetectable levels of hepatitis B virus (HBV) DNA compared with seven other therapies (such as lamivudine: odds ratio 33.0; 95% credible interval 7.0-292.7). For HBeAg-negative patients, the large network (seven therapies) ranked entecavir alone or in combination with tenofovir highly for reduction in HBV DNA and histologic improvement. In the smaller network (three therapies), tenofovir ranked first for undetectable HBV DNA and histologic improvement. No data existed to directly or indirectly compare these treatments.

CONCLUSION

For HBeAg-positive patients tenofovir is the most effective at increasing efficacy, whereas for HBeAg-negative patients, either tenofovir or entecavir is most effective. Further research should focus on strengthening the network connections, in particular comparing tenofovir and entecavir in HBeAg-negative patients.

The efficacy of zinc finger antiviral protein against hepatitis B virus transcription and replication in tansgenic mouse model

AIM

The zinc finger antiviral protein (ZAP) is a mammalian host restriction factor, and it could inhibit HBV RNA synthesis in vitro experiments. However, the role of ZAP against HBV in vivo environment is unclear. This study aimed to investigate whether ZAP could act against HBV transcription and replication in ZAP tansgenic mouse model.

METHODS

HBV-replication-competent plasmid pHBV4.1 was transferred to ZAP transgenic ICR mouse via the tail vein using a hydrodynamic in vivo transfection procedure, and ICR mouse were used as controls. HBV RNA and HBV DNA replication intermediates in the liver were respectively analyzed by Northern blotting and Southern blotting. The expression of hepatitis B surface antigen (HBsAg) and hepatitis B core antigen (HBcAg) in the liver tissue was detected by immunohistochemical staining.

RESULTS

As compared to ICR control mouse, the levels of 3.5 kb mRNA in ZAP transgenic mouse were decreased by 8.4%; while the level of HBV DNA replication intermediates was decreased by 82%. In addition, the expression of HBsAg and HBcAg in ZAP transgenic mouse liver were both significantly less than that of ICR control mouse.

CONCLUSIONS

Our findings suggest that ZAP could inhibit HBV replication in vivo in mice, which offers a new target for anti-HBV drug development.

Treating Immune-tolerant Hepatitis B

Hepatitis B virus (HBV) infection is a major cause of cirrhosis and hepatocellular carcinoma worldwide. On the basis of virus-host interactions, the natural history of HBV carriers can be divided into four chronological phases. In the first immune tolerance phase, HBV carriers are positive for hepatitis B e antigen (HBeAg) and have high HBV replication activity, normal ALT levels as well as minimal liver disease. Ample evidence has shown that patients in the immune tolerance phase have very low viral evolution and minimal risk of fibrosis progression. However, recent immunological studies argued that HBV-specific immune responses already exist in a proportion of immune-tolerant patients and the immune activities are comparable to those in the immune clearance phase. Regarding antiviral therapy, whether these immune-tolerant patients are indicated for treatment remains debated. Previous studies showed that HBeAg-positive patients with normal or near-normal ALT levels, who are assumed to be in the immune tolerance phase, have a lower HBeAg seroconversion rate receiving either pegylated interferon or nucleos(t)ide analogue treatment. The latest clinical trial focusing on-treatment response of immune-tolerant patients with tenofovir disoproxil fumarate-based therapy also confirmed the results. The HBeAg seroconversion rates are <5% at 4 years of treatment. Considering the minimal risk of disease progression and low treatment response rates in immune-tolerant patients, current antiviral therapy should not be recommended unless the patients have advanced liver fibrosis. In addition, novel agents targeting the HBV template known as covalently closed circular DNA and aiming to reduce or eliminate it are urgently required.

Designing immune therapy for chronic hepatitis B

Presently-available antiviral drugs may not be a satisfactory option for treatment of patients with chronic hepatitis B (CHB). In spite of presence of several antiviral drugs, sustained off-treatment clinical responses are not common in CHB patients treated with antiviral drugs. In addition, antiviral drug treatment may have limited effects on blocking the progression of HBV-related complications. However, substantial long-term risk of viral resistance and drug toxicity are related with maintenance antiviral therapy in CHB patients with presently-available antiviral agents. The infinite treatments with antiviral drugs for CHB patients are also costly and may be unbearable by most patients of developing and resource-constrained countries. In this situation, there is pressing need to develop new and innovative therapeutic approaches for patients with chronic hepatitis B virus (HBV) infection. Immune therapy has emerged as an alternate therapeutic approach for CHB patients because studies have shown that host immunity is either impaired or derailed or distorted or diminished in CHB patients compared to patients with acute resolved hepatitis B who contain the HBV replication and control liver damages. Both non antigen-specific immune modulators and HBV antigen-specific agents have been used in CHB patients during last three decades. However, similar to antiviral therapy, the ongoing regimens of immune therapeutic approaches have also been unable to show real promises for treating CHB patients. The concept of immune therapy for treating CHB patients seems to be rationale and scientific, however, concerns remain about suitable designs of immune therapy for CHB patients.

Antiviral Therapy of Liver Cirrhosis Related to Hepatitis B Virus Infection

Hepatitis B virus (HBV) infection is a leading cause of liver disease worldwide, with 75% of those affected distributed in the Asia-Pacific region. Approximately one million HBV-infected patients die of liver cirrhosis and hepatocellular carcinoma (HCC) each year. If left untreated, 6-20% of chronic hepatitis B (CHB) patients will develop cirrhosis over five years. The cumulative incidence of HBV-related cirrhosis, disease progression, and prognosis are closely associated with serum HBV DNA levels. Antiviral therapy in HBV-related cirrhosis has been documented by several long-term cohort studies to decrease disease progression to hepatic decompensation and HCC. The approval and availability of oral antiviral agents with better safety profiles has greatly improved the prognosis for HBV-related cirrhosis. Here, we discuss the significance of antiviral therapy for HBV-related cirrhosis and the management of HBV-related diseases in the future.

Liquid oral suspension adefovir dipivoxil (GS-02-526): an update on treatments for hepatitis B infection

Though the global epidemiology of hepatitis B virus infection has declined due to effective immunization, chronic hepatitis B (CHB) remains a serious public health problem and there is still a need for more treatment options that are efficient, safe and simple for different kinds of CHB patients. Adefovir dipivoxil (ADV) liquid suspension (GS-02-526), as a new form of oral ADV, not only has competent antiviral efficacy, but is also more convenient for patients with swallowing difficulties or patients with impaired renal function requiring dosage adjustment. The clinical data evaluating the safety, tolerability and antiviral activity of liquid suspension of ADV as well as its tablet are summarized in this article. The availability of liquid oral suspension of ADV would allow more patients to receive timely and reasonable antiviral treatments.

HBeAg-positive chronic hepatitis B: why do I treat my patients with pegylated interferon?

Although chronic hepatitis B (CHB) is a global health threat, it is now a preventable and treatable disease. Seven agents have been approved for the treatment of CHB. Although many patients prefer potent long-term nucleos(t)ide analogues (NAs) as the first-line therapy because they are convenient to use and well-tolerated, a finite duration of pegylated interferon (PEG-IFN) is still an attractive strategy because it provides higher rates of off-therapy host immune control over hepatitis B virus (HBV) compared with NAs. In addition, the rates of HBeAg/HBsAg loss or seroconversion increase over time in patients who respond to PEG-IFN therapy. Nevertheless, these benefits are limited to 30% of all patients, and significant adverse effects are still a concern. Therefore, patients who can benefit most from PEG-IFN therapy should be more carefully selected according to baseline host and viral predictors, such as age, ALT level, viral load, HBV genotype and HBV mutants. In addition, on-treatment predictors including HBV DNA, HBeAg and HBsAg kinetics, can help decide who should continue or discontinue PEG-IFN and shift to NA. Understanding these factors can help determine personalized PEG-IFN therapy for CHB patients. In the near future, the treatment paradigm of CHB should be tailored on the basis of viral (HBV DNA level, HBV genotype and HBV mutants) and host (age, gender, ALT level and host genetic polymorphisms) factors, disease status (stage of fibrosis and comorbidities) and the selection of antiviral agents (immunomodulatory effect, antiviral potency, adverse effects and rate of drug resistance).

Higher adherence with 3-year entecavir treatment than lamivudine or telbivudine in treatment-naïve Taiwanese patients with chronic hepatitis B

BACKGROUND AND AIMS

Oral nucleos(t)ide analogs (NAs) are effective in suppressing hepatitis B virus (HBV) replication in treatment naïve chronic hepatitis B (CHB) patients. However, little is known about the treatment modification and adherence on such patients with prolonged NA treatment.

METHODS

In this multicenter observational study, a total of 600 NA-naïve Taiwanese CHB patients aged 16 years and older were enrolled. The 600 patients were retrospectively identified by their NA treatment history from August 2008 to July 2009; this cohort was prospectively followed up over 3 years. During the 3-year period, incidence of treatment modifications, reasons for modification, and rate of adherence were evaluated.

RESULTS

Among the 583 evaluable patients, the initial NA treatment included entecavir (ETV) in 468 patients, telbivudine (LdT) in 67, and lamivudine (LVD) in 48. During the 3-year treatment, 9.0% of ETV-treated patients, 38.8% of LdT-treated patients, and 54.2% of LVD-treated patients had treatment modification. The main reasons for treatment modification were fulfilling stopping criteria in the ETV group (40.5%) and virological breakthrough in both the LdT (61.5%) and LVD (46.2%) groups. The proportion of patients with adherence rate (> 90%) at year 3 was 90.8% in the ETV group, 83.9% in the LdT group, and 83.9% in the LVD group.

CONCLUSIONS

Treatment-naïve CHB patients with a 3-year ETV treatment in Taiwan have the lower likelihood of treatment modification and better rate of adherence compared with those with LdT or LVD treatment.

Therapeutic potential of a combined hepatitis B virus surface and core antigen vaccine in patients with chronic hepatitis B

PURPOSE

The safety and clinical efficacy of a vaccine containing both hepatitis B surface antigen (HBsAg) and hepatitis B core antigen (HBcAg) (HBsAg/HBcAg) were evaluated in patients with chronic hepatitis B (CHB).

METHODS

Eighteen patients with CHB were administered a vaccine containing 100 μg of HBsAg and 100 μg of HBcAg. The vaccine was administered ten times at 2-weekly intervals, the first five times via the nasal route only and the subsequent five times via both nasal and subcutaneous routes. The safety and efficacy of this therapeutic approach were assessed by periodic assessment of the patients' general condition, viral kinetics, and biochemical parameters during treatment and 24 and 48 weeks after therapy. The production of cytokines by peripheral blood mononuclear cells (PBMC) and antigen-pulsed dendritic cells (DC) was evaluated to assess the immunomodulatory effects of the HBsAg/HBcAg vaccine in CHB patients.

RESULTS

The HBsAg/HBcAg vaccine was safe in all patients. No flare of HBV DNA or alanine aminotransferase (ALT) was recorded in any patient. Sustained HBV DNA negativity and persistently normalized ALT were detected in 9 (50 %) and 18 (100 %) patients with CHB, respectively. PBMC and HBsAg/HBcAg-pulsed DCs from HBsAg/HBcAg-vaccinated CHB patients produced significantly higher levels of various cytokines [interleukin 1β (IL-1β), IL-6, IL-8, IL-12, and tumor necrosis factor α (TNF-α)] than those from control unvaccinated CHB patients (p < 0.05) after stimulation with HBsAg/HBcAg in vitro.

CONCLUSION

HBsAg/HBcAg vaccine seems a safe and efficient therapeutic approach for patients with CHB.

HBsAg, HBcAg, and combined HBsAg/HBcAg-based therapeutic vaccines in treating chronic hepatitis B virus infection

BACKGROUND

As the host immunity is diminished in patients with chronic hepatitis B (CHB), different approaches have been used to up-regulate their immune responses to produce therapeutic effects. But, cytokines, growth factors and polyclonal immune modulators could not exhibit sufficient therapeutic effects in these patients. Immune therapy with HBV-related antigens (vaccine therapy) has been used in CHB patients. But there is a paucity of information about the design of HBV antigen-based immune therapy in these patients.

DATA SOURCE

Preclinical and clinical studies on immune therapy with HBsAg-based vaccine, HBcAg and combination of HBsAg/HBcAg-based vaccines have been discussed.

RESULTS

HBsAg-based prophylactic vaccine was used as an immune therapeutic agent in CHB patients; however, monotherapy with HBsAg-based immune therapy could not lead to sustained control of HBV replication and/or liver damages. HBsAg-based vaccine was used as a combination therapy with cytokines, growth factors, and antiviral drugs. HBsAg-based vaccine was also used for cell-based therapy. However, satisfactory therapeutic effects of HBsAg-based vaccine could not be documented in CHB patients. In the mean time, evidences have supported that HBcAg-specific immunity is endowed with antiviral and liver protecting capacities in CHB patients. Recent data concentrate on the clinical use of combined HBsAg- and HBcAg-based vaccines in CHB patients.

CONCLUSION

Antigen-based immune therapy with HBV-related antigens may be an alternative method for the treatment of CHB patients but proper designs of antigens, types of adjuvants, dose of vaccinations, and routes of administration need further analyses for the development of an effective regimen of immune therapy against HBV.

Chronic hepatitis B: Enlarged perihepatic lymph nodes correlated with hepatic histopathology

AIM: To assess the value of enlarged perihepatic lymph nodes in determining hepatic histopathology for chronic hepatitis B (CHB) by magnetic resonance imaging (MRI).

METHODS: Sixty-seven patients who were clinically and histologically diagnosed with CHB and 18 healthy subjects without history of liver disease underwent abdominal MRI. Histological diagnosis and hepatic inflammation (grade 0-4) and fibrosis (stage 0-4) were assessed by a simplified system for scoring in chronic viral hepatitis. The major imaging protocol included an axial breath-hold fat suppressed fast spoiled gradient echo T₂-weighted imaging (T₂WI), axial breath-trigger fat suppressed fast recovery fast spin echo T₂WI, and axial and coronal fast imaging employing steady-state acquisition. Perihepatic lymph nodes larger than 5 mm in shortest diameter were noted.

RESULTS: The numbers and size indexes of lymph nodes greater than 5 mm in shortest diameter in hepatic hilum suggested inflammatory activity for subjects with grade 2 or higher, with a high accuracy of diagnosis (the area under the curves > 0.9, P < 0.001). The numbers of lymph nodes were 2 or more with a sensitivity of 87.27%, a specificity of 90.00%, an accuracy of 88.24%, a positive predictive value of 94.12%, and a negative predictive value of 79.41% in patients with grade 2 or higher, and the size indexes were no less than 180 mm² with a sensitivity of 83.64%, a specificity of 100%, an accuracy of 89.41%, a positive predictive value of 100%, and a negative predictive value of 76.92%. The numbers and size indexes of lymph nodes were not correlated with hepatic fibrosis. The signal intensity indexes of lymph nodes were no significant correlation with histological grading or staging of liver.

CONCLUSION: The numbers and size indexes of enlarged perihepatic lymph nodes for patients with CHB suggest inflammatory activity for subjects with grade 2 or higher.

Non-antigen-specific and antigen-specific immune therapies for chronic hepatitis B: evidences from laboratory benches and patient's bedsides

INTRODUCTION

Due to unsatisfactory therapeutic efficacy and considerable side effects of antiviral drugs in patients with chronic hepatitis B (CHB), immunotherapy has emerged as an alternative approach. CHB immunotherapy may be categorized into two main types: i) non-antigen-specific immune therapy and ii) hepatitis B virus (HBV) antigen-specific immune therapy. Although different immune modulators have been used in CHB patients for the last two to three decades, the nature and design of ongoing regimens of immunotherapeutic approaches need considerable modifications.

AREAS COVERED

In this review, the authors have outlined the relevant immunotherapies for CHB patients that have been used for the last two to three decades. The mechanisms underlying the limited therapeutic efficacy of available therapeutic agents for CHB patients have been discussed to aid in the development of an effective therapeutic approach for these patients.

EXPERT OPINION

Circumstantial evidence indicates that a better regimen of immunotherapy may be developed using different HBV-related antigens or combinations of two or more HBV-related antigens, or combinations of HBV-related antigens and antiviral drugs. However, the capacity of 'inducible immunity' by immune modulators to cure or block progression of liver diseases in CHB patients needs to be addressed.

Clinical utility of quantitative HBsAg in natural history and nucleos(t)ide analogue treatment of chronic hepatitis B: new trick of old dog

Using commercial quantitative assays, quantitative hepatitis B surface antigen (qHBsAg) has improved our understanding and management of chronic hepatitis B (CHB). The HBsAg level is highest in the immune tolerance phase, starts to decline during the immune clearance phase, and decreases slowly but progressively after hepatitis B e antigen (HBeAg) seroconversion. The HBsAg level is lowest in individuals with an inactive carrier state but higher in those who develop HBeAg-negative hepatitis. It has been shown that a reduction of HBsAg by 1 log IU/mL or more reflects improved host immune control of HBV infection. A combination of HBsAg <1000 IU/mL and HBV-DNA <2000 IU/mL can identify a 3-year inactive state in a genotype D HBeAg-negative carrier population. In the Asian-Pacific region, where HBV genotypes B and C are dominant, HBsAg levels of ≤10-100 IU/mL predict HBsAg loss over time. As to the prediction of disease progression, low-viremic carriers with HBsAg >1000 IU/mL have been shown to be at higher risks of HBeAg-negative hepatitis, cirrhosis, and hepatocellular carcinoma than those with HBsAg <1000 IU/mL. Although qHBsAg has been widely used in CHB patients receiving pegylated interferon therapy, the HBsAg decline is slow and does not correlate with HBV-DNA levels during nucleos(t)ide analogue (NUC) therapy. However, a rapid HBsAg decline during NUC therapy may identify patients who will finally clear HBsAg. A 6- to 12-monthly assessment of HBsAg level could be considered during NUC therapy. Taking these lines of evidence together, qHBsAg can complement HBV-DNA levels to optimize the management of CHB patients in our daily clinical practice.

Adherence, persistence, healthcare utilization, and cost benefits of guideline-recommended hepatitis B pharmacotherapy

OBJECTIVE

To compare pharmacotherapy adherence, persistence, and healthcare utilization/costs among US patients with chronic hepatitis B (CHB) initiated on an oral antiviral monotherapy recommended as first-line treatment by current national (US) guidelines vs an oral antiviral not recommended as first-line monotherapy.

RESEARCH DESIGN AND METHODS

In this retrospective cohort study, patients aged 18-64 with medical claims for CHB who initiated an oral antiviral monotherapy for CHB between 07/01/05 and 01/31/10 were identified from a large US commercial health insurance claims database. Patients were continuously enrolled for a 6-month baseline period and ≥90 days follow-up. They were assigned to 'currently recommended first-line therapy' (RT: entecavir or tenofovir) or 'not currently recommended first-line therapy' (NRT: lamivudine, telbivudine, or adefovir) cohorts.

MAIN OUTCOME MEASURES

Multivariate analyses were conducted to compare treatment adherence, persistence, healthcare utilization, and costs for RT vs NRT cohorts.

RESULTS

Baseline characteristics were similar between RT (n=825) and NRT (n=916) cohorts. In multivariate analyses, RT patients were twice as likely as NRT patients to be adherent (OR=2.09; p<0.01) and persistent (mean: RT=361 days, NRT=298 days; p<0.01) and half as likely to have an inpatient stay (OR=0.527; p<0.01). Between the two oral antivirals recommended as first-line treatment, even though pharmacy cost was higher for entecavir, mean total healthcare costs for entecavir and tenofovir were similar ($1214 and $1332 per patient per month, respectively). Similar results were also observed with regard to adherence, persistence, and healthcare use for entecavir and tenofovir.

CONCLUSIONS

A limitation associated with analysis of administrative claims data is that coding errors can be mitigated but are typically not fully eradicated by careful study design. Nevertheless, the current findings clearly indicate the benefits of initiating CHB treatment with an oral antiviral monotherapy recommended as first-line treatment by current guidelines.