Treatment with Peg-interferon alpha-2b for HBeAg-positive chronic hepatitis B: HBsAg loss is associated with HBV genotype

Toward a Functional Cure for Hepatitis B

Current treatment of chronic hepatitis B virus (HBV) infection, pegylated interferon-α (pegIFN-α) and nucleos(t)ide analogue (NA), can suppress HBV replication, reverse liver inflammation and fibrosis, and decrease risks of cirrhosis and hepatocellular carcinoma, but hepatitis B surface antigen (HBsAg) loss is rare. Functional HBV cure is defined as undetectable HBsAg and unquantifiable serum HBV DNA for at least 24 weeks after a finite course of therapy. This requires suppression of HBV replication and viral protein production as well as restoration of immune response to HBV. Direct-acting antivirals targeting virus entry, capsid assembly, viral protein production and secretion are in clinical trials. In parallel, immune modulatory therapies to stimulate HBV-specific immune response and to remove immune blockade are being tested. Clinical trials of direct-acting antivirals alone or immune modulatory therapies alone have not been successful in achieving HBV cure. Recent combinations of direct-acting antivirals and immune modulatory therapies have shown promising results particularly with combinations that included pegIFN-α. These results need to be confirmed in larger studies with longer follow-up, and further work is needed to develop simpler regimens with fewer drugs that can be administered orally and safely. While there is a strong desire to develop finite therapies that can achieve HBV cure, safety is paramount and new therapies must provide incremental value compared to standard of care, which is predominantly long-term NA therapy.

Advances in discovery of novel investigational agents for functional cure of chronic hepatitis B: A comprehensive review of phases II and III therapeutic agents

Chronic hepatitis B virus (HBV) infection affects over 295 million people globally and an estimated 1.6 million people in the United States. It is associated with significant morbidity and mortality due to cirrhosis, liver failure, and liver cancer. Antiviral therapy with oral nucleos(t)ide analogues is associated with high rates of virologic suppression, which in turn has been associated with a decreased risk of liver complications. However, current antiviral regimens are limited by concerns with adverse effects, adherence, resistance, long-term treatment, and ongoing risk for liver events. Novel investigational agents are currently in development and are targeted at achieving functional cure with sustained hepatitis B surface antigen (HBsAg) loss and suppression of HBV DNA. Herein we review key evidence from phases II and III trials defining the efficacy and safety profiles for key investigational agents for functional cure of chronic hepatitis B, including core/capsid inhibitors, entry inhibitors, RNA interference (siRNA/ASO), HBsAg inhibitors, Toll-like receptor agonists, checkpoint inhibitors, and therapeutic vaccines.

Pangenomic antiviral effect of REP 2139 in CRISPR/Cas9 engineered cell lines expressing hepatitis B virus surface antigen

Chronic hepatitis B remains a global health problem with 296 million people living with chronic HBV infection and being at risk of developing cirrhosis and hepatocellular carcinoma. Non-infectious subviral particles (SVP) are produced in large excess over infectious Dane particles in patients and are the major source of Hepatitis B surface antigen (HBsAg). They are thought to exhaust the immune system, and it is generally considered that functional cure requires the clearance of HBsAg from blood of patient. Nucleic acid polymers (NAPs) antiviral activity lead to the inhibition of HBsAg release, resulting in rapid clearance of HBsAg from circulation in vivo. However, their efficacy has only been demonstrated in limited genotypes in small scale clinical trials. HBV exists as nine main genotypes (A to I). In this study, the HBsAg ORFs from the most prevalent genotypes (A, B, C, D, E, G), which account for over 96% of human cases, were inserted into the AAVS1 safe-harbor of HepG2 cells using CRISPR/Cas9 knock-in. A cell line producing the D144A vaccine escape mutant was also engineered. The secretion of HBsAg was confirmed into these new genotype cell lines (GCLs) and the antiviral activity of the NAP REP 2139 was then assessed. The results demonstrate that REP 2139 exerts an antiviral effect in all genotypes and serotypes tested in this study, including the vaccine escape mutant, suggesting a pangenomic effect of the NAPs.

Randomized Trial of Tenofovir With or Without Peginterferon Alfa Followed by Protocolized Treatment Withdrawal in Adults With Chronic Hepatitis B

INTRODUCTION

Hepatitis B surface antigen (HBsAg) loss is associated with improved long-term outcomes of patients with chronic hepatitis B but is infrequently achieved with current monotherapies. We assessed whether combination strategies that included treatment withdrawal enhanced HBsAg loss.

METHODS

A randomized (1:1) trial of tenofovir disoproxil fumarate (TDF) for 192 weeks with or without peginterferon (PegIFN) alfa-2a for the first 24 weeks, followed by withdrawal of TDF at week 192 with 48 weeks of off-treatment follow-up to week 240. The primary end point was HBsAg loss at week 240.

RESULTS

Of 201 participants (52% HBeAg positive, 12%/6% genotype A/A2, 7% cirrhosis) randomized to TDF + PegIFN (n = 102) or TDF alone (n = 99), 6 participants had lost HBsAg at the end of the treatment phase (week 192), 5 (5.3%) in the combination group, and 1 (1.0%) in the TDF alone group ( P = 0.09). By week 240, 9 participants had cleared HBsAg, 5.3% in combination, and 4.1% in monotherapy arms ( P = 0.73). HBsAg decline and loss occurred earlier with TDF + PegIFN than TDF, with a ≥1-logIU/mL qHBsAg decline by week 24 in 28% in TDF + PegIFN compared with 6% in TDF ( P = 0.04). HBsAg loss occurred in 7 of 12 (58%) with hepatitis B virus subgenotype A2 (all HBeAg positive) compared with only 2 of 189 (1%) with other hepatitis B virus genotypes and in 8 of 93 (8.6%) HBeAg positive vs 1 of 87 (1.1%) HBeAg negative.

DISCUSSION

PegIFN combined TDF followed by protocolized TDF withdrawal led to earlier but not higher percentages of HBsAg clearance. Pretreatment HBeAg positivity and subgenotype A2 were strongly associated with HBsAg clearance.

Kinetics changes in total cholesterol predict HBeAg seroconversion in chronic hepatitis B patients treated with pegylated interferon-alfa

There is no satisfactory standard for predicting HBeAg seroconversion during Pegylated interferon alpha (PegIFNα) treatment. Studies have shown that IFNα therapy in chronic hepatitis C patients could alter serum lipid profiles. However, there have been no studies on lipid changes that predict the outcome of PegIFNα monotherapy in treated-naive chronic hepatitis B (CHB) patients. This retrospective study included 130 treated-naive HBeAg-positive CHB patients receiving PegIFNα monotherapy. The relationship between serum lipid changes and HBeAg seroconversion was analysed. The TC-ALT-HBsAg-HBeAg-Genotype-Age (CASEGA) model was established to predict HBeAg seroconversion after PegIFN-α monotherapy. Among 130 patients, 33 achieved HBeAg seroconversion (SR) and 97 did not achieve HBeAg seroconversion (NR). The decrease in serum total cholesterol (TC) in the NR group was significantly higher than in the SR group at Week 24 (-9.59% vs. -0.31%, p < 0.001). Multivariate logistic regression analysis showed that the change in TC at Week 24 (odds ratio = 1.065, p = 0.009) was an independent predictor of HBeAg seroconversion. The area under the receiver operating characteristic curve for the CASEGA model was 0.883. The model score at the maximum Youden index was 90, and the specificity, sensitivity, positive predictive value and negative predictive value were 0.727, 0.794, 0.546 and 0.895, respectively. The HBeAg seroconversion rate at Week 72 in patients with scores >90 was significantly higher than that in patients with scores <90 (54.55% vs. 10.47%, p < 0.001). This study indicated that the change in the TC level at 24 weeks in CHB patients treated with PegIFNα was associated with HBeAg seroconversion. The CASEGA prediction model based on the TC change rate of 24 weeks has good predictive efficiency for HBeAg seroconversion.

What will it take to cure hepatitis B?

The current treatment of chronic HBV infection, pegylated interferon-α (pegIFNα) and nucleos(t)ide analog (NA), can suppress HBV replication, reverse liver inflammation and fibrosis and reduce the risks of cirrhosis, HCC, and HBV-related deaths, but relapse is common when the treatment is stopped before HBsAg loss. There have been major efforts to develop a cure for HBV, defined as sustained HBsAg loss after a finite course of therapy. This requires the suppression of HBV replication and viral protein production and the restoration of immune response to HBV. Direct-acting antivirals targeting virus entry, capsid assembly, viral protein production and secretion are in clinical trials. Immune modulatory therapies to stimulate adaptive or innate immunity and/or to remove immune blockade are being tested. NAs are included in most and pegIFNα in some regimens. Despite the combination of 2 or more therapies, HBsAg loss remains rare in part because HbsAg can be derived not only from the covalently closed circular DNA but also from the integrated HBV DNA. Achievement of a functional HBV cure will require therapies to eliminate or silence covalently closed circular DNA and integrated HBV DNA. In addition, assays to differentiate the source of circulating HBsAg and to determine HBV immune recovery, as well as standardization and improvement of assays for HBV RNA and hepatitis B core-related antigen, surrogate markers for covalently closed circular DNA transcription, are needed to accurately assess response and to target treatments according to patient/disease characteristics. Platform trials will allow the comparison of multiple combinations and channel patients with different characteristics to the treatment that is most likely to succeed. Safety is paramount, given the excellent safety profile of NA therapy.

Molecular clones of genetically distinct hepatitis B virus genotypes reveal distinct host and drug treatment responses

Background & Aims

HBV exhibits wide genetic diversity with at least 9 genotypes (GTs), which differ in terms of prevalence, geographic distribution, natural history, disease progression, and treatment outcome. However, differences in HBV replicative capacity, gene expression, and infective capability across different GTs remain incompletely understood. Herein, we aimed to study these crucial aspects using newly constructed infectious clones covering the major HBV GTs.

Methods

The replicative capacity of infectious clones covering HBV GTs A-E was analyzed in cell lines, primary hepatocytes and humanized mice. Host responses and histopathology induced by the different HBV GTs were characterized in hydrodynamically injected mice. Differences in treatment responses to entecavir and various HBV capsid inhibitors were also quantified across the different genetically defined GTs.

Results

Patient-derived HBV infectious clones replicated robustly both in vitro and in vivo. GTs A and D induce more pronounced intrahepatic and proinflammatory cytokine responses which correlated with faster viral clearance. Notably, all 5 HBV clones robustly produced viral particles following transfection into HepG2 cells, and these particles were infectious in HepG2-NTCP cells, primary human hepatocytes and human chimeric mice. Notably, GT D virus exhibited higher infectivity than GTs A, B, C and E in vitro, although it was comparable to GT A and B in the human liver chimeric mice in vivo. HBV capsid inhibitors were more readily capable of suppressing HBV GTs A, B, D and E than C.

Conclusions

The infectious clones described here have broad utility as genetic tools that can mechanistically dissect intergenotypic differences in antiviral immunity and pathogenesis and aid in HBV drug development and screening.

Lay summary

The hepatitis B virus (HBV) is a major contributor to human morbidity and mortality. HBV can be categorized into a number of genotypes, based on their specific genetic make-up, of which 9 are well known. We isolated and cloned the genomes of 5 of these genotypes and used them to create valuable tools for future research on this clinically important virus.

Clinical Efficacy of PEG-IFNα-2a and PEG-IFNα-2b in the Treatment of Hepatitis B e Antigen-Positive Hepatitis B and Their Value in Improving Inflammatory Factors and Hemodynamics in Patients: A Comparative Study

Objective

To compare the merits and demerits of PEG-IFNα-2a and PEG-IFNα-2b for the treatment of hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB).

Methods

Clinical files from eighty-four CHB patients admitted to the Second Hospital of Shanxi Medical University between January 2018 and January 2019 were retrospectively analyzed and assigned to two groups: group 2a treated with PEG-IFNα-2a and group 2b treated with PEG-IFNα-2b. The clinical efficacy was compared between the above two arms, and the liver function (ALT, AST, HA, LN, and IV-C), HBV-DNA, HBsAg, HBeAg, and inflammatory factors (IFs, IL-1β, IL-6, IL-8, and TNF-α) were tested at 12 weeks (T1), 24 weeks (T2), and 48 weeks (T3). The alterations of hemodynamics (SBP, DBP, MAP, and CVP), cardiac function (LVEF and BNP), and the incidence of adverse reactions (ARs) during treatment were recorded. Finally, the patients were followed up for 2 years to investigate the quality of life (QOL) as well as the positive seroconversion rate of HBsAg and HBeAg.

Results

The overall response rate was similar in the two arms (P > 0.05). After treatment, the liver function, HBV-DNA, HBsAg, HBeAg, IFs, hemodynamics, and cardiac function were enormously improved (P < 0.05), with faster improvement in group 2b compared with group 2a (P < 0.05). The investigation of ARs identified notably lower incidence rates of alopecia, thrombocytopenia, and granulocytopenia in group 2a as compared to group 2b (P < 0.05). The prognostic follow-up results revealed no distinct difference in the QOL score and the positive seroconversion rate of HBsAg and HBeAg (P > 0.05); however, the quantitative results of HBV-DNA, HBsAg, and HBeAg in group 2b were lower than those in group 2a (P < 0.05).

Conclusions

Both PEG-IFNα-2a and PEG-IFNα-2b have excellent and stable therapeutic effects on HBeAg-positive CHB, among which PEG-IFNα-2b renders a faster treatment process but higher side effects, which can provide valuable references when choosing a treatment plan for CHB.

[Ten years of the National Reference Center for hepatitis B viruses and hepatitis D viruses in Giessen, Germany: activities and experiences]

The National Reference Center (NRC) for hepatitis B viruses (HBV) and hepatitis D viruses (HDV) has been located at the Institute of Medical Virology of the Justus Liebig University (JLU) in Giessen, Germany, since its establishment in 2011. This paper describes the NRC's areas of activity and related experience.The NRC offers comprehensive consulting services on all diagnostic and clinical aspects of acute and chronic HBV and HDV infections for the Public Health Service (ÖGD), diagnostic laboratories, clinics, research institutes, and physicians in private practice. Uncertain diagnostic findings can be analyzed and interpreted and epidemiological correlations clarified with the HBV/HDV special diagnostics established at the NRC using state-of-the-art molecular, biochemical, and genetic laboratory tools. The NRC has access to a strain collection of many well-characterized and cloned HBV/HDV isolates, allowing comparative analysis and evaluation of antiviral resistance mutations and immune escape variants. Together with its national and international partner institutions, the NRC initiates and supervises, among other things, interlaboratory studies for the diagnosis of HBV resistance and immune escape for the establishment and validation of international World Health Organization (WHO) standards and for the improvement of quantitative HDV genome determination. The NRC actively participates in current recommendations and guidelines on HBV and HDV and the recommendations of medical societies. It also highlights current HBV/HDV-relevant aspects with contributions in the form of national and international lectures as well as original articles and comments in national and international journals.

A simple-to-use tool for predicting response to peginterferon in HBV DNA suppressed chronic hepatitis B patients in China

BACKGROUND

Rational administration of peginterferon can remarkably reduce serum HBsAg level and improve the rate of HBsAg loss. Considering the high cost and adverse drug reaction of peginterferon, we aimed to develop a simple-to-use scoring system at early stage of treatment to predict low HBsAg level or HBsAg clearance at the end of treatment in virological suppression chronic hepatitis B (CHB) patients.

METHODS

Non-cirrhotic CHB patients with NA (nucleoside/nucleotide analogues)-induced virological suppression initiated either by add-on or switch-to peginterferon for ≥ 48 weeks were enrolled from January 2012 to June 2017 in these two tertiary centers. The retrospective experiment identified 320 suitable patients, including 192 in training and 128 in validation cohorts.

RESULTS

Using logistic regression, a simple-to-use scoring system integrating baseline HBsAg level <1000 IU/mL, HBsAg decline >0.5 log at week 12 and ALT flare at week 12 was developed in the training cohort and good for predicting HBsAg <100 IU/mL, HBsAg <10 IU/mL and HBsAg loss at the end of 48-week treatment. The area under receiver operating characteristics curve was 0.84, 0.86 or 0.78 in the training cohort and 0.88, 0.79 or 0.81 in the validation cohort, respectively.

CONCLUSIONS

Our simple-to-use scoring system may guide for clinicians to decide whether to continue peginterferon in CHB patients to achieve low HBsAg levels or HBsAg clearance at the end of treatment, which might lead more cost-effective decision and get more patients to reach functional cures in Chinese population.

HBsAg, Subviral Particles, and Their Clearance in Establishing a Functional Cure of Chronic Hepatitis B Virus Infection

In diverse viral infections, the production of excess viral particles containing only viral glycoproteins (subviral particles or SVP) is commonly observed and is a commonly evolved mechanism for immune evasion. In hepatitis B virus (HBV) infection, spherical particles contain the hepatitis B surface antigen, outnumber infectious virus 10 000-100 000 to 1, and have diverse inhibitory effects on the innate and adaptive immune response, playing a major role in the chronic nature of HBV infection. The current goal of therapies in development for HBV infection is a clinical outcome called functional cure, which signals a persistent and effective immune control of the infection. Although removal of spherical SVP (and the HBsAg they carry) is an important milestone in achieving functional cure, this outcome is rarely achieved with current therapies due to distinct mechanisms for assembly, secretion, and persistence of SVP, which are poorly targeted by direct acting antivirals or immunotherapies. In this Review, the current understanding of the distinct mechanisms involved in the production and persistence of spherical SVP in chronic HBV infection and their immunoinhibitory activity will be reviewed as well as current therapies in development with the goal of clearing spherical SVP and achieving functional cure.

Hepatitis B Virus Covalently Closed Circular DNA Predicts Postoperative Liver Cancer Metastasis Independent of Virological Suppression

New antiviral therapies against hepatitis B virus (HBV) focus on the elimination of covalently closed circular DNA (cccDNA). However, traditional cccDNA-specific quantitative PCR (qPCR) has a narrow effective range, hindering a reliable comparison between the levels of biopsy-derived cccDNAs. Collaterally, the prognostic role of cccDNA in HBV-related hepatocellular carcinoma (HCC) cannot be clearly defined. Here, we developed a peptide nucleic acid (PNA)-clamping qPCR method to provide a wider range of specific cccDNA quantification (up to 5 logs of effective range). Extrachromosomal DNA was extracted from para-neoplastic tissues for cccDNA quantification. In total, 350 HBV-related HCC patients were included for an outcome analysis. Without differential pre-dilution, cccDNA levels in para-neoplastic liver tissues were determined, ranging from < 2 × 10³ to 123.0 × 10⁶ copies/gram. The multivariate linear regression analysis showed that cccDNA was independently correlated with the HBV e antigen (p < 0.001) and serum HBV-DNA levels (p = 0.012). The Cox proportional hazard model analysis showed that cccDNA independently predicted overall survival (p = 0.003) and extrahepatic metastasis-free survival (p = 0.001). In virologically suppressed HCC patients, cccDNA still effectively predicted intrahepatic recurrence-free (p = 0.003) and extrahepatic metastasis-free (p = 0.009) survivals. In conclusion, cccDNA independently predicted postoperative extrahepatic metastasis-free survival.

Developing a sensitive HBV genotyping assay for HBV DNA suppressed patients using both DNA and RNA sequencing

Hepatitis B virus (HBV) genotypes impact treatment outcomes and disease progression. The current genotyping methods have limitations in patients with low HBV viral load. In this study, a more sensitive assay has been developed for determining the HBV genotype in HBV DNA suppressed patients. Fifty-five serum samples from 55 chronic hepatitis B patients (HBeAg-, n = 20; HBeAg+, n = 35) across genotypes A to H with long-term nucleos(t)ide analogs (NAs) treatment were collected. All samples had HBV DNA less than 29 IU/mL. Total nucleic acid (viral DNA and RNA) was extracted and a 341 bp amplicon located at HBV S gene overlapping with reverse transcriptase domain of polymerase (pol/RT) was amplified via real time (RT)-nested polymerase chain reaction (PCR) followed by population sequencing. HBV genotype was determined by phylogenetic analysis. The assay successfully amplified HBV S/RT gene from 53 of 55 (96.4%) patient serum samples. Phylogenetic analysis demonstrated that the genotypes of all the 53 PCR positive samples matched the historical genotypes as determined by INNO-LiPA or RT sequence from the corresponding baseline samples. This assay was able to accurately determine HBV genotype irrespective of baseline genotype, HBeAg status, or duration of viral suppression. The ability to determine genotype in virally suppressed patients may facilitate the evaluation of novel treatment agents for HBV in this patient population.

The evolution and clinical impact of hepatitis B virus genome diversity

The global burden of hepatitis B virus (HBV) is enormous, with 257 million persons chronically infected, resulting in more than 880,000 deaths per year worldwide. HBV exists as nine different genotypes, which differ in disease progression, natural history and response to therapy. HBV is an ancient virus, with the latest reports greatly expanding the host range of the Hepadnaviridae (to include fish and reptiles) and casting new light on the origins and evolution of this viral family. Although there is an effective preventive vaccine, there is no cure for chronic hepatitis B, largely owing to the persistence of a viral minichromosome that is not targeted by current therapies. HBV persistence is also facilitated through aberrant host immune responses, possibly due to the diverse intra-host viral populations that can respond to host-mounted and therapeutic selection pressures. This Review summarizes current knowledge on the influence of HBV diversity on disease progression and treatment response and the potential effect on new HBV therapies in the pipeline. The mechanisms by which HBV diversity can occur both within the individual host and at a population level are also discussed.

Impact of Hepatitis B Virus Genetic Variation, Integration, and Lymphotropism in Antiviral Treatment and Oncogenesis

Chronic Hepatitis B Virus (HBV) infection poses a significant global health burden. Although, effective treatment and vaccinations against HBV are available, challenges still exist, particularly in the development of curative therapies. The dynamic nature and unique features of HBV such as viral variants, integration of HBV DNA into host chromosomes, and extrahepatic reservoirs are considerations towards understanding the virus biology and developing improved anti-HBV treatments. In this review, we highlight the importance of these viral characteristics in the context of treatment and oncogenesis. Viral genotype and genetic variants can serve as important predictive factors for therapeutic response and outcomes in addition to oncogenic risk. HBV integration, particularly in coding genes, is implicated in the development of hepatocellular carcinoma. Furthermore, we will discuss emerging research that has identified various HBV nucleic acids and infection markers within extrahepatic sites (lymphoid cells). Intriguingly, the presence of hepatocellular carcinoma (HCC)-associated HBV variants and viral integration within the lymphoid cells may contribute towards the development of extrahepatic malignancies. Improved understanding of these HBV characteristics will enhance the development of a cure for chronic HBV infection.

In Vitro Systems for Studying Different Genotypes/Sub-Genotypes of Hepatitis B Virus: Strengths and Limitations

Hepatitis B virus (HBV) infects the liver resulting in end stage liver disease, cirrhosis, and hepatocellular carcinoma. Despite an effective vaccine, HBV poses a serious health problem globally, accounting for 257 million chronic carriers. Unique features of HBV, including its narrow virus-host range and its hepatocyte tropism, have led to major challenges in the development of suitable in vivo and in vitro model systems to recapitulate the HBV replication cycle and to test various antiviral strategies. Moreover, HBV is classified into at least nine genotypes and 35 sub-genotypes with distinct geographical distributions and prevalence, which have different natural histories of infection, clinical manifestation, and response to current antiviral agents. Here, we review various in vitro systems used to study the molecular biology of the different (sub)genotypes of HBV and their response to antiviral agents, and we discuss their strengths and limitations. Despite the advances made, no system is ideal for pan-genotypic HBV research or drug development and therefore further improvement is required. It is necessary to establish a centralized repository of HBV-related generated materials, which are readily accessible to HBV researchers, with international collaboration toward advancement and development of in vitro model systems for testing new HBV antivirals to ensure their pan-genotypic and/or customized activity.

Enhancing the antivirus activity of chimeric canine interferon with ricin subunit B by using nanoparticle formulations

Despite interferon alpha having a broad spectrum of antiviral activity and strong antiproliferative activity, its applications are severely limited due to the intrinsic properties of proteins, such as poor stability and short serum half-life. In our study, canine interferon alpha (CaIFNα) gene was fused with the ricin toxin B chain (RTB) to form rCaIFNα/RTB, which encodes a 463-amino acid protein containing a 15-amino acid encoded (G₄S)₃ flexible linker. After expression in prokaryote, purification and renaturation, the cytotoxicity and antiviral activity of rCaIFNα/RTB were investigated in Madin–Darby canine kidney (MDCK) cells. rCaIFNα/RTB exerted a superior anti-vesicular stomatitis virus (VSV) activity on MDCK cells. Furthermore, we have developed a nanoparticle formulation of rCaIFNα/RTB by using polyethylenimine (PEI) through electrostatic interaction. rCaIFNα/RTB@PEI₁₀₀₀₀ is more stable than rCaIFNα/RTB at various pH and temperature levels, and it possesses enhanced antiviral activity. Our findings facilitate further research on the role of type I IFN in antiviral defense responses in Canis lupus familiaris.

Despite interferon alpha having a broad spectrum of antiviral activity and strong antiproliferative activity, its applications are severely limited due to the intrinsic properties of proteins, such as poor stability and short serum half-life.

Immunological Efficacy of Tenofovir Disproxil Fumarate-Containing Regimens in Patients With HIV-HBV Coinfection: A Systematic Review and Meta-Analysis

Background: Hepatitis B virus (HBV) coinfection is common in HIV-positive patients. HIV infection modifies the natural course of HBV infection, leading to a faster progression of liver-related morbidity and mortality than is observed in HBV mono-infected patients. This systematic review and meta-analysis evaluates the current clinical evidence regarding the use of oral tenofovir disproxil fumarate (TDF)-based treatments in patients coinfected with HIV and HBV.

Methods: We performed a comprehensive literature search in PubMed and Web of Science. Supplementary searches were conducted in Google Scholar and Clinicaltrials.gov. We conducted a random effects meta-analysis using the event rate (ER) to estimate the incidence of HBV seroconversion. A subgroup meta-analysis was performed to assess the moderate effects of demographic and disease-related variables on HBsAg loss. This review is registered in the PROSPERO database (CRD42018092379).

Results: We included 11 studies in the review. The immunological effects of oral TDF-based Pre-exposure prophylaxis (PrEP) treatment in patients with HIV-HBV coinfection were 0.249 for HBeAg loss, 0.237 for HBeAg conversion, 0.073 for HBsAg loss, and 0.055 for HBsAg conversion. The factors associated with HBsAg loss were the baseline HBV viral load, participant’s location, and a history of exposure to lamivudine/emtricitabine (3TC/FTC) (all p < 0.05). A trend toward a negative relationship between the baseline CD4⁺ T-cell count and HBsAg loss was observed (p = 0.078).

Conclusion: This systematic review and meta-analysis demonstrated that TDF-containing regimens are effective at stimulating HBeAg loss (24.9%), HBeAg conversion (23.7%), HBsAg loss (7.3%), and HBsAg conversion (5.5%) in HIV-HBV coinfected patients. The moderator analysis showed that HBV viral load, the location of participants, and prior exposure to 3TC/FTC are factors associated with HBsAg loss. Asian ethnicity, prior exposure to 3TC, and a nondetectable baseline HBV viral load are associated with lower odds of HBsAg loss. Well-designed prospective cohort studies and randomized controlled trials (RCTs) with large sample sizes are required for the investigation of potential predictors and biological markers associated with strategies for achieving HBV remission in patients with HIV-HBV coinfection, which is a matter of considerable importance to clinicians and those responsible for health policies.

An easy-to-use baseline scoring system to predict response to peginterferon alfa-2a in patients with chronic hepatitis B in resource-limited settings

BACKGROUND

Approximately one-third of patients have durable responses after finite (48-week) treatment with peginterferon alfa-2a. The ability to identify patients likely to respond would be particularly useful in resource-limited settings.

METHODS

Data from 1,363 peginterferon alfa-2a recipients (955 hepatitis B 'e' antigen [HBeAg]-positive and 408 -negative) in six studies were analysed. Baseline scoring systems were developed using generalized additive models and multiple logistic regression analysis to predict virological response (VR; HBV DNA <2,000 IU/ml), alone or combined with alanine aminotransferase (ALT) normalization (CR) at 24 weeks post-treatment.

RESULTS

Based on the final models, points were assigned for age ≥45 (0) or <45 years (1); male (0) or female (1); hepatitis B surface antigen (HBsAg) >25,000 (0), >7,500-≤25,000 (1), >1,250-≤7,500 (2) or ≤1,250 IU/ml (4); HBV DNA >5 (0) or ≤5 log₁₀ IU/ml (2) and ALT ratio >1-7 (0) or either ≤1 or >7 (1). Higher total scores (range 0-9) indicate higher likelihood of response. VR and CR rates were 28.5% (388/1,363) and 24.4% (332/1,363), respectively, and increased with increasing score: score 0-1 (n=257), VR 14.8%, CR 12.8%; score 2-3 (n=711), VR 23.1%, CR 20.1%; score ≥4 (n=395), VR 47.1%, CR 39.5%.

CONCLUSIONS

An easy-to-use baseline scoring system for use in settings where HBeAg status and HBV genotypes are unavailable would allow clinicians to identify patients with a low or high chance of achieving a durable post-treatment response to peginterferon alfa-2a. The tool can be used to inform treatment decisions in resource-limited settings.

Plasma miR-146a predicts serological conversion of hepatitis B e-antigen (HBeAg) in chronic hepatitis B patients treated with nucleotide analogs

Background

To investigate the association of plasma miR-146a with serological conversion of hepatitis B e-antigen (HBeAg) in patients with chronic hepatitis B (CHB) treated with nucleotide analogs (NAs).

Methods

This was a retrospective study of 115 HBeAg-positive patients with CHB treated at Xiangya Hospital, Central South University, Changsha, China, between September 2009 and March 2014. Patients were grouped according to whether they had achieved seroconversion of HBeAg by 104 weeks of NAs treatment. We assessed plasma miR-146a using miScript polymerase chain reaction (PCR). Serum alanine transaminase (ALT), hepatitis B virus (HBV) deoxyribonucleic acid (DNA) load, hepatitis B surface antigen (HBsAg) titer, HBeAg titer, and plasma miR-146a were measured at 0, 24, 48, and 104 weeks of treatment. Finally, we also determined ΔmiR-146a_24w and ΔmiR-146a_48w.

Results

ΔmiR-146a_48w was independently associated with seroconversion of HBeAg at 104 weeks [odds ratio (OR) =1.302; 95% confidence interval (CI), 1.159-1.962; P=0.029]. We obtained an area under the receiver operating characteristic (ROC) curve (AUC) of ΔmiR-146_48w of 0.757 for seroconversion of HBeAg (P=0.013). At the optimal cutoff value equivalent to a Youden index of 67.9%, the specificity and sensitivity of ΔmiR-146_48w were 63.7% and 88.3%, respectively. Positive (PPV) and negative (NPV) predictive values were 70.87% and 84.48%, respectively.

Conclusions

ΔmiR-146a_48w was independently associated with seroconversion of HBeAg in CHB patients treated with NAs.

Drugs in the Pipeline for HBV

Chronic hepatitis B remains a significant cause of morbidity and mortality worldwide. Most hepatitis B virus (HBV)-infected individuals are neither diagnosed nor treated. In those treated, nucleos(t)ide polymerase inhibitors persistently suppress viremia to the limits of quantitation; however, few achieve a "functional cure," defined as sustained off-treatment loss of detectable serum HBV DNA with or without loss of hepatitis B surface antigen. The low cure rate has been attributed to an inability to eliminate the viral reservoir of covalently closed circular DNA from hepatocytes. This review focuses on the diverse therapeutic approaches currently under development that may contribute to the goal of HBV cure.

Incidence and determinants of spontaneous hepatitis B surface antigen seroclearance and seroconversion in hepatitis B e antigen-negative chronic infection patients: A population-based prospective cohort

Seroclearance of hepatitis B surface antigen (HBsAg) has been widely studied; however, seroconversion of HBsAg and characteristics of viral load among hepatitis B e antigen (HBeAg)-negative chronic infection patients after HBsAg lost is not clear. We performed a large-scale study in a HBeAg-negative chronic infection cohort to evaluate spontaneous HBsAg seroclearance incidence from October 2012 to April 2017 in Jiangsu province, China. We also elucidated the characteristics of HBsAg seroconversion and hepatitis B virus (HBV) DNA detectability among patients who cleared HBsAg. A total of 2997 HBeAg-negative chronic infection patients (mean age 52.3 ± 12.9 years at baseline) were included. With 10 519 person-years of follow-up, 348 patients successfully spontaneously cleared HBsAg, with an incidence rate of 3.31 per 100 person-years. Patients with HBV DNA detectable ~1999 IU/mL at baseline had a lower probability of HBsAg seroclearance relative to those with undetectable HBV DNA, with a hazard ratio of 0.31 (95% CI = 0.23, 0.41). HBsAg seroconversion occurred in 37.3% of those patients who cleared HBsAg. The geometric mean of anti-HBs among those with HBsAg conversion was 79.4 mIU/mL. Female had a higher HBsAg seroconversion rate (P = 0.011). Among those with HBsAg seroclearance, 11.2% still had HBV DNA levels of higher than 100 IU/mL. Patients with higher HBV DNA at baseline had a higher risk of detectable HBV DNA levels even after HBsAg seroclearance (P < 0.001). This study reveals HBsAg seroconversion rates and HBV DNA undetectability epidemiological characteristics of patients with HBsAg seroclearance and suggests that monitoring HBV DNA is needed when managing HBeAg-negative chronic patients, even after clearing HBsAg.

Genetic diversity of hepatitis viruses in West-African countries from 1996 to 2018

The severity of hepatic pathology and the response to treatment depend on the hepatitis virus genotype in the infected host. The objective of this review was to determine the distribution of hepatitis virus genotypes in West African countries. A systematic review of the literature in PubMed, Google Scholar and Science Direct was performed to identify 52 relevant articles reporting hepatitis A, B, C, D, E and G viruses genotypes. Hepatitis B virus (HBV) genotype E with a prevalence of 90.6% (95%CI: 0.891-0.920) found in this review, is characterized by low genetic diversity. Hepatitis C virus (HCV) genotypes 1 and 2 represented 96.4% of HCV infections in West African countries, while hepatitis delta virus, hepatitis A virus, hepatitis G virus genotypes 1 and HEV genotype 3 were reported in some studies in Ghana and Nigeria. HBV genotype E is characterized by high prevalence, low genetic diversity and wide geographical distribution. Further studies on the clinical implications of HBV genotype E and HCV genotypes 1 and 2 are needed for the development of an effective treatment against this viral hepatitis in West African countries. Surveillance of the distribution of different genotypes is also needed to reduce recombination rates and prevent the emergence of more virulent viral strains.

Serum sphingolipid levels associate with upcoming virologic events and HBV genotype D in a cohort of patients with HBeAg-negative HBV infection

OBJECTIVES

Sphingolipids (SLs) have been implicated as potent regulators of the hepatitis B virus (HBV) life cycle. We investigated the SL biomarker potential regarding virologic endpoints in a prospective subgroup of patients with HBeAg-negative chronic HBV infection.

METHODS

From 2009-2016 98 patients with HBeAg-negative HBV infection were prospectively followed over four years. Clinical, laboratory and imaging data were evaluated annually. SLs were assessed in available serum probes via liquid chromatography coupled to tandem mass spectrometry.

RESULTS

Of those 98 patients, 10 (10.2%) showed HBV reactivation, 13 (13.2%) lost HBsAg and 9 (9.1%) gained status of HBsAg-/HBsAb-coexistence, whereas 66 (67.3%) had no events. Within the four-year analysis sphingosine (p = 0.020), sphinganine (p<0.001), dhS1P (p<0.001), C16DHC (p<0.01) and C20Cer (p<0.001) showed a significant upregulation in patients without virologic events, C18Cer significantly decreased (p<0.001). At baseline decreased S1P-, dhS1P- and C16Cer-levels were observed in patients with upcoming status of HBsAg-/HBsAb-coexistence. S1P and dhS1P levels were elevated HBV genotype D infected patients.

CONCLUSIONS

In a prospective cohort of patients with a HBeAg-negative HBV infection, serum SLs associated with the virologic course and HBV genotype D. Further studies are required to elucidate SLs as potential novel predictors of the course of HBeAg-negative HBV infection.

Chinese Herbal Medicine Combined with Entecavir for HBeAg Positive Chronic Hepatitis B: Study Protocol for a Multi-Center, Double-Blind Randomized-Controlled Trial

BACKGROUND

The domestic prevalence of chronic hepatitis B (CHB) in China is 7.18% in 2006, imposing great societal healthcare burdens. Nucleot(s)ide analogues (NUCs) anti-hepatitis B virus (HBV) therapies are widely applied despite the relatively low rate of seroconversion and high risk of drug-resistant mutation. More effective treatments for CHB deserve further explorations. Combined therapy of NUCs plus Chinese herbal medicine (CHM) is widely accepted in China, which is recognized as a prospective alternative approach. The study was primarily designed to confirm the hypothesis that Tiaogan-Yipi Granule (, TGYP) or Tiaogan-Jianpi-Jiedu Granule (, TGJPJD) plus entecavir tablet (ETV) was superior over ETV monotherapy in enhancing HBeAg loss rate.

METHODS

The study was a nationwide, large-scale, multi-center, double-blind, randomized, placebo-controlled trial with a designed duration of 108 weeks. A total of 16 hospitals and 596 eligible Chinese HBeAg positive CHB patients were enrolled from November 2012 to September 2013 and randomly allocated into 2 groups in 1:1 ratio via central randomization system: experimental group (EG) and control group (CG). Subjects in EG received CM formulae (TGYP or TGJPJD, 50 g per dose, twice daily) plus ETV tablet (or ETV placebo) 0.5 mg per day in the first 24 weeks (stage 1), and CHM granule plus ETV tablet (0.5 mg per day) from week 25 to 108 (stage 2). Subjects in CG received CHM Granule placebo plus ETV tablet (0.5 mg per day) for 108 weeks throughout the trial. The assessments of primary outcomes (HBV serum markers and HBV-DNA) were conducted by a third-party College of American Pathologists (CAP) qualified laboratory. Adverse effects were observed in the hospitals of recruitment.

DISCUSSION

The study was designed to compare the curative effect of CM plus ETV and ETV monotherapy in respect of HBeAg loss, which is recognized by the European Association for the Study of the Liver as "a valuable endpoint". We believe this trial could provide a reliable status for patients' "journey" towards durable responses after treatment discontinuation. The trial was registered before recruitment on Chinese Clinical trial registry (No. ChiCTR-TRC-12002784, Version 1.0, 2015/12/23).

HIV, HCV and HBV: A Review of Parallels and Differences

Elimination of the three blood-borne viruses—human immunodeficiency virus (HIV), hepatitis B (HBV) and hepatitis C (HCV)—as public health issues may be plausible in the near future. Spectacular advances have been made with the introduction of highly effective antiviral agents into clinical practice, and prevention strategies are available for all three infections. Effective disease control, laid out by WHO global strategies, is currently feasible for all three viruses. However, for worldwide elimination of these viruses, effective vaccines are required that are currently only available for HBV. In this review differences and parallels among HIV, HCV and HBV will be discussed with a focus on virologic and therapeutic issues, and prospects for the future of HBV will be presented.

A baseline tool for predicting response to peginterferon alfa-2a in HBeAg-positive patients with chronic hepatitis B

BACKGROUND

Peginterferon induces off-treatment responses in approximately one-third of patients with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B.

AIM

To develop an easy-to-use baseline prediction score to identify hepatitis B virus (HBV) genotype B-/C-infected HBeAg-positive Asian patients likely to respond to peginterferon alfa-2a.

METHODS

Generalised additive models, multiple logistic regression (MLR) analysis and internal validation methods were applied to data from 647 HBeAg-positive patients from China, Hong Kong and Taiwan to develop a scoring system to predict response 24 weeks after completing a 48-week course of peginterferon alfa-2a.

RESULTS

Five baseline factors (age, sex, alanine aminotransferase ratio, hepatitis B surface antigen (HBsAg) level and HBV DNA level) were retained in the final MLR for HBeAg seroconversion and used to develop a scoring system from 0 to 7. Among patients with scores of 0-1, 2-3, 4 or ≥5, HBeAg seroconversion was achieved in 6.4% (6/94), 23.0% (61/265), 36.4% (67/184) and 54.8% (57/104), respectively, and a combined response (HBeAg seroconversion plus HBV DNA <2000 IU/mL) in 5.3% (5/94), 12.8% (34/265), 25.0% (46/184) and 36.5% (38/104), respectively. Among patients with scores of 0-1, 2-3, 4 or ≥5, 57.0% (53/93), 12.3% (31/253), 3.4% (6/178) and 1.0% (1/100) had HBsAg ≥20 000 IU/mL at treatment Week 12; only 3/91 (3.3%) with HBsAg ≥20 000 IU/mL experienced a combined response at 24 weeks post-treatment (negative predictive value = 97% [88/91]).

CONCLUSION

A pre-treatment scoring system using readily available baseline characteristics identifies HBeAg-positive Asian patients likely to experience sustained HBeAg seroconversion after treatment with peginterferon alfa-2a.

How viral genetic variants and genotypes influence disease and treatment outcome of chronic hepatitis B. Time for an individualised approach?

Chronic hepatitis B virus (HBV) infection remains a global problem. Several HBV genotypes exist with different biology and geographical prevalence. Whilst the future aim of HBV treatment remains viral eradication, current treatment strategies aim to suppress the virus and prevent the progression of liver disease. Current strategies also involve identification of patients for treatment, namely those at risk of progressive liver disease. Identification of HBV genotype, HBV mutants and other predictive factors allow for tailoured treatments, and risk-surveillance pathways, such as hepatocellular cancer screening. In the future, these factors may enable stratification not only of treatment decisions, but also of patients at risk of higher relapse rates when current therapies are discontinued. Newer technologies, such as next-generation sequencing, to assess drug-resistant or immune escape variants and quasi-species heterogeneity in patients, may allow for more information-based treatment decisions between the clinician and the patient. This article serves to discuss how HBV genotypes and genetic variants impact not only upon the disease course and outcomes, but also current treatment strategies. Adopting a personalised genotypic approach may play a role in future strategies to combat the disease. Herein, we discuss new technologies that may allow more informed decision-making for response guided therapy in the battle against HBV.

Peginterferon is preferable to entecavir for prevention of unfavourable events in patients with HBeAg-positive chronic hepatitis B: A five-year observational cohort study

At present, the long-term effects of pegylated interferon-α (PEG-IFN-α) and entecavir (ETV) are controversial. Studies directly compared the long-term outcomes of these two drugs have not been completed. This study was designed to compare the clinical outcomes of PEG-IFN-α vs ETV therapy in Chinese patients with chronic HBV infection. From September 2008 to December 2016, a large, observational, open-label, prospective cohort study of HBeAg-positive patients with CHB who received PEG-IFN-α or ETV therapy was carried out at the Second Affiliated Hospital of Chongqing Medical University. Cumulative incidences of unfavourable events were calculated with respect to treatment type. Based on the REACH-B model, we compared the observed incidence of hepatocellular carcinoma (HCC) with the expected incidence in each group. PEG-IFN-α-treated patients showed a lower cumulative incidences of unfavourable events and cirrhosis than those treated with ETV (P = .031; P = .044, respectively). Impact factor exploration indicated that treatment type and platelet count are significantly associated with the occurrence of unfavourable events. Based on the REACH-B model, a lower observed cumulative incidence of HCC was observed in PEG-IFN-α-treated patients than predicted (P = .038). However, there was no significant difference of the cumulative HCC incidence between the observed and the predicted cases for ETV-experienced patients (P = .36). Treatment with PEG-INF-α leads to a lower incidence of unfavourable events including cirrhosis and HCC than ETV in patients with HBV. Treatment type and baseline platelet count may be two important factors associated with the long-term clinical outcomes of patients with CHB.

Tenofovir alafenamide demonstrates broad cross-genotype activity against wild-type HBV clinical isolates and maintains susceptibility to drug-resistant HBV isolates in vitro

Tenofovir alafenamide (TAF) is a novel prodrug of tenofovir (TFV). This study evaluated the antiviral activity of TAF against wild-type genotype A-H HBV clinical isolates as well as adefovir-resistant, lamivudine-resistant, and entecavir-resistant HBV isolates. Full length HBV genomes or the polymerase/reverse transcriptase (pol/RT) region from treatment-naïve patients infected with HBV genotypes A-H were amplified and cloned into an expression vector under the control of a CMV promoter. In addition, 11 drug resistant HBV constructs were created by site-directed mutagenesis of a full length genotype D construct. Activity of TAF was measured by transfection of each construct into HepG2 cells and assessment of HBV DNA levels following treatment across a range of TAF concentrations. TAF activity in vitro was similar against wild-type genotype A-H HBV clinical isolates. All lamivudine- and entecavir-resistant isolates and 4/5 adefovir-resistant isolates were found to be sensitive to inhibition by TAF in vitro as compared to the wild-type isolate. The adefovir-resistant isolate rtA181V + rtN236T exhibited low-level reduced susceptibility to TAF. TAF is similarly active in vitro against wild-type genotype A-H HBV clinical isolates. The TAF sensitivity results for all drug-resistant isolates are consistent with what has been observed with the parent drug TFV. The in vitro cell-based HBV phenotyping assay results support the use of TAF in treatment of HBV infected subjects with diverse HBV genotypes, in both treatment-naive and treatment-experienced HBV infected patients.

Molecular diversity in irregular or refugee immigrant patients with HBV-genotype-E infection living in the metropolitan area of Naples

In a recent testing in the metropolitan area of Naples, Italy, on 945 irregular immigrants or refugees, 87 HBsAg chronic carriers were identified, 53 of whom were infected by HBV-genotype E. The aim of the present study was to identify the genetic diversity of HBV-genotype E in these 53 immigrants. The 53 immigrant patients with HBV-genotype-E infection were born in Africa, central or eastern Asia, eastern Europe or Latin America. These patients had been seen for a clinical consultation at one of the four first-level units from January 2012 to 2013. The first dataset contained 53 HBV-S gene isolates plus 128 genotype/subgenotype specific reference sequences downloaded from the National Center for Biotechnology Information. The second dataset, comprising the 53 HBV-S gene isolates, previously classified as HBV-genotype E, was used to perform the time-scaled phylogeny reconstruction using a Bayesian approach. Phylogenetic analysis showed that all 53 HBV-S isolates belonged to HBV-genotype E. Bayes factor analysis showed that the relaxed clock exponential growth model fitted the data significantly better than the other models. The time-scaled Bayesian phylogenetic tree of the second dataset showed that the root of the tree dated back to the year 1990 (95% HPD:1984-2000). Four statistically supported clusters were identified. Cluster A dated back to 2012 (95% HPD:1997-2012); cluster B dated back to 2008 (95% HPD:2001-2015); cluster C to 2006 (95% HPD:1999-2013); cluster D to 2004 (95% HPD:1998-2011). This study disclosed the genetic evolution and phylogenesis in a group of HBV-genotype-E-infected immigrants. J. Med. Virol. 89:1015-1024, 2017. © 2016 Wiley Periodicals, Inc.

Interferon Treatment for Hepatitis B

Chronic hepatitis B virus (HBV) infection has a significant public health impact. There are currently 7 approved therapies for chronic HBV, including standard and pegylated interferon (IFN)-α, and 5 nucleos(t)ide analogs (NUCs). IFN offers benefits over NUCs, including a finite duration of therapy and a higher rate of clearance of hepatitis Be antigen and surface antigen. These benefits need to be weighed against the potential adverse effects of IFN therapy. Some patients should not receive IFN because of advanced liver disease or comorbidities. This article reviews the mechanisms of action, efficacy, and clinical use of IFN therapy for HBV infection.

Hepatitis B virus genotypes among chronic hepatitis B patients reporting at Korle-Bu teaching hospital, Accra, Ghana

Introduction

Knowledge of hepatitis B virus (HBV) genotype is an important predictive variable which might have an impact in management and treatment of patients with chronic hepatitis B infection. In Ghana very little information is available on hepatitis B genotypes. This study was conducted to determine the distribution of HBV genotypes circulating among chronic hepatitis B patients reporting at the Korle-Bu Teaching Hospital (KBTH), Accra, Ghana.

Methods

Blood samples (10 ml) were collected from 250 consenting patients. DNA was extracted and amplified using polymerase chain reaction technique. Restriction fragment length polymorphism (RFLP) was used for the detection of genotypes.

Results

Out of the 250 chronic hepatitis B patients who were HBsAg positive, 91 (36.4%) were males aged 29.8 ± 9.1 and 159 (63.6%) females aged 33± 12.1 years. HBV DNA was detected in 111 (44.4%) but only 58 (52%) of these were typeable. These were classified as genotype A, 8 (7.2%); genotype D, 3 (2.7%) and genotype E, 47 (42.3%). Our results did not show any association between the infecting genotype and age (X²= 0.923; p-value=0.623) or gender (X²= 0.283, p= 0.579).

Conclusion

Consistent with similar studies worldwide, the results suggest that genotypes A, D and E were the genotypes circulating among chronic hepatitis B patients who reported to the Korle-Bu Teaching Hospital with genotype E being the most predominant and therefore constitutes an important public health concern. We recommend further epidemiological studies to understand the implication of genotype E in terms of disease progression and treatment.

Treatment strategies according to genotype for chronic hepatitis B in children

This review article was requested by editor-in-chief of this journal as 'pediatric CHB treatment' for the upcoming special issue. The main objective of chronic hepatitis B (CHB) treatment is diminishing the risk of complications related to chronic liver disease. In Asia, there are already some reports about hepatocellular carcinoma (HCC) in hepatitis B virus (HBV) infected children. The key points of treatment in children with CHB infections are selection of which patients to treat and conformation of the optimal therapy time that would reduce viral resistance. The choice of therapy is determined by the district (Western/Eastern), HBV genotype, medical accessibility, and economic state of the country. Newly developed nucleos(t)ide analogues (NAs) are potent in children with CHB. However, to improve therapeutic efficacy, physicians are recommended to follow treatment guidelines and determine the specific genotype in the CHB patient. In this article, the treatment of pediatric CHB is reviewed according to differences in genotype.

Chronic Hepatitis B Virus Infection: Disease Revisit and Management Recommendations

Chronic hepatitis B virus (HBV) infection evolves from immune-tolerance phase, through immune clearance phase to a quiescent phase or reactivation as hepatitis B e antigen-negative hepatitis. Persistent infection may result in the development of cirrhosis and hepatocellular carcinoma (HCC). Host factors including gender, age, family history, HLA-DP, and viral factors including HBV DNA, genotypes, precore mutations, pre-S deletions, and hepatitis B surface antigen (HBsAg) level are associated with the development of these complications. Risk scores for the development of HCC have been derived. Patients with persistently elevated alanine aminotransferase levels (>30 for males; >19 U/L for females) and HBV DNA levels >2000 IU/mL should be treated. Patients with established cirrhosis with detectable HBV DNA should also be treated. The recommended first-line agents include pegylated interferon and 2 nucleos(t)ide analogs, entecavir and tenofovir. NAs require long-term treatment to maintain suppression of HBV DNA. They have been shown to decrease hepatic fibrosis, or reverse cirrhosis and to reduce the development of HCC. They have very low rates (0% to 1.2%) of resistance. HBsAg seroclearance, although the ideal endpoint, is only achievable in 10% to 12% of patients by multicenter trials usually studying relatively young patients. Patients on long-term treatment should be monitored for viral breakthrough that may be due to noncompliance or the development of resistance. Newer agents are under trials to enhance the rate of HBsAg seroclearance. However, even with the current NAs, long-term treatment of >6 years can markedly reduce the covalently closed circular DNA, the viral component responsible for initiation of viral replication.

Hepatitis B and D viruses replication interference: Influence of hepatitis B genotype

AIM: To study the hepatitis B virus (HBV) and hepatitis D virus (HDV) replication interferences in patients with chronic hepatitis delta infected with different HBV genotypes.

METHODS: We conducted a transversal study including 68 chronic hepatitis delta (CHD) (37 HIV-positive) patients and a control group of 49 chronic hepatitis B (CHB) (22 HIV-positive) patients. In addition, a dynamic follow-up was performed in 16 CHD patients. In all the samples, the surface antigen of hepatitis B (HBsAg) serum titers were analyzed with the Monolisa HBsAg Ultra system (Bio-Rad), using as quantification standard a serial dilution curve of an international HBsAg standard. Serum HBV-DNA titers were analyzed using the Roche Cobas TaqMan (Roche, Barcelona, Spain), and the serum HDV-RNA using an in-house real-time qRT-PCR method, with TaqMan probes. HBV genotype was determined with the line immunoassay LiPA HBV genotyping system (Innogenetics, Ghent, Belgium). In those patients negative for LiPA assay, a nested PCR method of complete HBsAg coding region, followed by sequence analysis was applied.

RESULTS: No differences in the HBV-DNA levels were found in CHB patients infected with different HBV genotypes. However, in CHD patients the HBV-DNA levels were lower in those infected with HBV-A than in those with HBV-D, both in HIV negative [median (IQR): 1.25 (1.00-1.35) vs 2.95 (2.07-3.93) log₁₀ (copies/mL), P = 0.013] and HIV positive patients [2.63 (1.24-2.69) vs 7.25 (4.61-7.55) log₁₀ (copies/mL), P < 0.001]. This was confirmed in the dynamic study of the HBV/HDV patients. These differences induce an under-estimation of HBV-A incidence in patients with CHD analyzed with LiPA assay. Finally, the HBsAg titers reflected no significant differences in CHD patients infected with HBV-A or D.

CONCLUSION: Viral replication interference between HBV and HDV is HBV-genotype dependent, and more evident in patients infected with HBV-genotype A, than with HBV-D or E.

HBsAg loss in a New Zealand community study with 28-year follow-up: rates, predictors and long-term outcomes

BACKGROUND AND AIMS

HBsAg seroclearance is the most desired endpoint in chronic hepatitis B (CHB) but occurs uncommonly. Recent studies have shown baseline HBsAg levels to be predictive of HBsAg loss up to 10 years. We report the 28-year rates of HBsAg loss and outcomes in the Kawerau study cohort from New Zealand, and assess the predictive value of baseline HBsAg levels to predict long-term HBsAg loss.

METHODS

The 1984 Kawerau community study identified 572 CHB patients, followed up for 28 years (41 % HBeAg-positive, median age 17 years, range 1-71 years). In 2012, surviving individuals attended a local clinic for an interview, blood tests and transient elastography.

RESULTS

384/218 (74 %) surviving individuals attended the clinic in 2012. Spontaneous HBsAg loss occurred in 145 (33 %) after 12,702 person-years of follow-up (1.14 per 100 person-years). Liver stiffness measurements were significantly lower if HBsAg loss occurred <50 years (mean 6.1 kPa) versus >50 years (mean 11.6 kPa), p = 0.0002. No HCC occurred following HBsAg loss (median follow-up 72 months). Predictors of HBsAg loss were older age and lower baseline HBsAg level (HR for HBsAg loss at 28 years 2.7 (95 % CI 1.7-4.2), 6.7 (95 % CI 3.9-11.4) and 9.4 (95 % CI 5.2-16.9), respectively, for HBsAg 1000-9999, 100-999 and <100 IU/mL compared to HBsAg >10,000 IU/mL at baseline, (p < 0.0001). Baseline HBsAg was a superior predictor of HBsAg loss compared to HBV DNA at all time-points: AUROC at 15 years: 0.87 (95 % CI 0.82-0.93) versus 0.73 (95 % CI 0.66-0.80) (p < 0.0001) and AUROC at 28 years: 0.74 (95 % CI 0.69-0.79) versus 0.67 (95 % CI 0.62-0.72) (p = 0.0007). The optimal cut-off HBsAg level to predict HBsAg seroclearance at 28 years is HBsAg <10,000 IU/mL (sensitivity 72 %, specificity 64 %, NPV 88 %).

CONCLUSIONS

Rates of HBsAg loss in our community cohort were high, and occurred earlier than previously reported. Earlier HBsAg loss was associated with less severe liver fibrosis. Baseline HBsAg level was a good predictor of long-term HBsAg loss up to 28 years and superior to HBV DNA.

Virological and serological tools to optimize the management of patients with chronic hepatitis B

Molecular biology techniques are routinely used to diagnose and monitor treatment in patients with chronic hepatitis B (CHB). These tools can detect and quantify viral genomes and analyse their sequences to determine genotype. The increasing use of these tools to monitor patients has greatly improved the management of CHB infection by maximizing the potential for individualized treatment. HBV genotyping has become increasingly important and provides additional information to predict a response to therapy. More sensitive methods to determine HBV DNA levels are now available and the units of measurements have been standardized. HBsAg levels in serum have been shown to reflect active intrahepatic covalently closed circular DNA (cccDNA) and to have additional value in treatment decisions, especially as an on-treatment marker.

Monotherapy for hepatitis B infection: a review of treatment options

Chronic hepatitis B (CHB) is a global health problem, causing liver failure, cirrhosis and hepatocellular carcinoma. CHB treatment aims to prevent liver-related complication. The treatment of CHB infection includes monotherapy with either interferons (IFNs) or nucleos(t)ide (NUC) analogs. IFNs have moderate antiviral effects, and their use is limited by side effects. With the availability of NUCs, IFN-intolerant and decompensated cirrhotic patients began to be treated. Lamivudine and telbivudine, nucleoside analogs, have low genetic barrier to resistance. Adefovir, a nucleotide analog, has moderate potency and potential nephrotoxicity. Entecavir and tenofovir, with their high potency, high genetic barrier to resistance and favorable safety profile are the standard of care in CHB treatment. Long-term use of NUCs with maintained viral suppression results in a decrease in liver-related complications.

Serological and clinical outcomes of horizontally transmitted chronic hepatitis B infection in New Zealand Māori: results from a 28-year follow-up study

BACKGROUND

Chronic hepatitis B infection is endemic in New Zealand and has high prevalence in New Zealand Māori. Previous longitudinal studies in populations with predominantly vertically acquired chronic hepatitis B have shown low spontaneous hepatitis B surface-antigen (HBsAg) seroclearance rates: 0.5-1.4% annually (mean age of clearance 48 years). We report the 28-year follow-up data on clinical and serological outcomes in indigenous New Zealand Māori with early horizontally acquired HBV.

METHODS

In 1984, community seroprevalence study identified 572 HBsAg-positive individuals, followed for 28 years. Liver-related mortality and hepatocellular carcinoma (HCC) incidence were compared between these 572 HBV carriers and 1140 HBsAg-negative matched case-controls. Surviving HBsAg-positive individuals have been followed up in 2012 with clinical assessment, blood tests and liver transient elastography. Rates of hepatitis B e-antigen (HBeAg) and HBsAg seroconversion were determined.

RESULTS

After total 13 187.4 person-years follow-up, 15 HBsAg-positive patients have developed HCC compared with none of the HBsAg-negative controls (p<0.001). 12 HBsAg-positive patients died from liver-related causes compared with none in the controls (p<0.001). Spontaneous HBeAg-seroconversion occurred in 91% of HBeAg-positive patients. Spontaneous HBsAg loss occurred in 33% overall (annual clearance rate 1.34%), with higher rates at older ages (1.05% in patients<20 years at entry vs 4.3% per annum >40 years at entry, p<0.0001). Median ages of HBeAg loss and HBsAg loss were 23 years (range 6-66 years) and 40 years (range 4-80 years), respectively.

CONCLUSIONS

Horizontally transmitted HBV in Maori is similarly associated with increased risk of liver-related mortality and HCC compared with Chinese, although absolute incidence rates are lower. The rates of HBeAg and HBsAg loss are high, and occur at an earlier age than previously reported.

Hepatitis B virus genotypes and variants

At least 10 hepatitis B virus (HBV) genotypes (A to J) with distinct geographic distributions and several HBV mutants, including precore/core promoter mutations and pre-S/S deletion mutations, have been recognized to be not only predictive of liver disease progression but also associated with response to antiviral therapy. HBV genotype-specific pathogenesis may contribute to heterogeneous clinical outcomes in chronic hepatitis B patients across the world. For example, patients with HBV genotypes C and D infection have a lower rate of spontaneous HBeAg seroconversion. In addition, HBV genotypes C and D have a higher frequency of core promoter and pre-S mutations than genotypes A and B. Genotypes C and D also carry a higher lifetime risk of cirrhosis and HCC development than genotypes A and B. Core promoter and pre-S mutations also correlate with an increased risk of hepatocellular carcinoma (HCC). Therapeutically, genotypes A and B patients have a better response to interferon-based therapy than genotypes C and D patients, but the response to nucleos(t)ide analogs is comparable across different HBV genotypes. In conclusion, HBV genotypes and variants may serve as viral genetic markers to predict disease progression as well as help practicing physicians optimize individualized antiviral therapy in clinical practice.

HBsAg plasma level kinetics: a new role for an old marker as a therapy response predictor in vertically infected children on combination therapy

We aimed to investigate the ability of HBsAg plasma level kinetics to predict therapy response by studying 23 children with infancy-acquired chronic hepatitis B (CHB) during combination sequential therapy with lead-in lamivudine (LAM) and add-on interferon-α (IFN-α) [5 responders (R = anti-HBs seroconversion) and 18 nonresponders (NR)] and to assess their relationship with pretreatment intrahepatic HBV-DNA and cccDNA and HBsAg and HBcAg liver expression. Plasma HBsAg levels were measured in samples before (treatment week 0 = TW0), during (TW9, TW28, TW52) and after (follow-up week = FUW24) therapy by Abbott ARCHITECT(®) assay [log10 IU/mL]. Baseline liver HBV-DNA and cccDNA were quantified by real-time TaqMan PCR [log10 copies/ng genomic DNA]. HBsAg and HBcAg liver expression was evaluated by immunostaining of formalin-fixed, paraffin-embedded specimens [number of positive cells/1000 hepatocytes]. All results are presented as medians. Plasma: at baseline, on-treatment and during follow-up, HBsAg levels were lower in R than NR (TW0: 4.36 vs 4.75;TW28: 2.44 vs 4.35;TW52: 0 vs 4.08 and FUW24: 0.17 vs 4.35, all P < 0.05). Liver: baseline HBV-DNA (3.82 vs 4.71, P = 0.16) and cccDNA (1.98 vs 2.26, P = 0.18) tended to be lower in R than NR, HBsAg expression was lower in R than NR (0.5 vs 4.7, P = 0.03), and HBcAg expression was similar between R and NR. There were positive correlations between plasma HBsAg levels and liver HBV-DNA (r = 0.44, P = 0.04), cccDNA (r = 0.41, P = 0.04) and HBsAg liver expression (r = 0.38, P = 0.05). Lower baseline HBsAg plasma levels, lower HBsAg expression in liver and on-treatment decline of plasma HBsAg levels heralds HBsAg clearance and response to treatment in tolerant children with CHB.

Influence of the basal core promoter and precore mutation on replication of hepatitis B virus and antiviral susceptibility of different genotypes

Mutations in the basal core promoter (BCP) and precore (PC) regions of the hepatitis B virus (HBV) are more common in genotypes B and C than in genotype A, suggesting that these mutations might affect replication competency depending on genotype. The purpose of the study was to investigate the influence of these mutations on the capacity of HBV for replication and antiviral drug susceptibility according to genotype. Genotypes A, B, and C of HBV strains with a BCP mutation, PC mutation, or BCP + PC mutation were made by site-directed mutagenesis. Replication competency of each construct and susceptibility to nucleos(t) ide analogues were tested in an Huh7 cell line. In genotype A, the BCP and BCP + PC mutations increased the viral replication around 6.5 times compared with the wild type, and the PC mutation alone similarly increased the viral replication around three times. In genotypes B and C, all three mutant types increased viral replication to a similar extent, regardless of mutation pattern. Interestingly, the BCP mutation appeared to have a greater effect on viral replication in genotype A than in genotypes B and C. This finding was unexpected because the BCP mutation is more common in HBV genotypes B and C. Moreover, the BCP, PC, and BCP + PC mutations decreased the sensitivity of HBV to antiviral agents to various degrees (2- to 10-fold) regardless of genotype. In conclusion, BCP and PC mutations increased viral replication regardless of HBV genotype and decreased in vitro antiviral susceptibility to the nucleos(t) ide analogues.

Loss of hepatitis B surface antigen in a real-life clinical cohort of patients with chronic hepatitis B virus infection

BACKGROUND & AIMS

Hepatitis B surface antigen (HBsAg) clearance is the main indicator of viral cure in patients infected with the hepatitis B virus (HBV). We sought to identify the parameters associated with HBsAg loss in a well-characterized real-life clinical cohort of chronically HBV-infected patients.

METHODS

Patients with chronic HBV infection were prospectively included, classified according to the disease stage, and followed up to determine parameters associated with HBsAg clearance.

RESULTS

In total, 315 patients were followed up for a mean of almost 6 years. At study entry, 109 (34.6%) were inactive HBsAg carriers, 204 (64.8%) had chronic active hepatitis (CAH), and two (0.6%) were immune-tolerant carriers. During follow-up, 128 (62.7%) of the 204 patients with CAH received antiviral therapy. Sixty-nine had HBeAg-positive CAH: 55 (79.7%) were treated and 14 (20.3%) untreated. One hundred thirty-five had HBeAg-negative CAH: 73 (54.1%) were treated and 62 (45.9%) untreated. Inactive carriers showed an annual HBsAg clearance incidence rate of 23.4 cases per 1000 persons-years, which was higher than that of CAH groups. The clearance incidence rates (in cases per 1000 persons-years) of CAH groups were: treated HBeAg-positive (20.7), untreated HBeAg-positive (19.1), treated HBeAg-negative (10.1), and untreated HBeAg-negative (8.1). Older age (P = 0.001) and inactive carrier status (P = 0.019) were independent predictors of HBsAg clearance.

CONCLUSION

In a well-characterized real-life clinical cohort of chronically HBV-infected patients in various disease phases, older age, and inactive HBsAg carrier status were the only predictors of HBsAg clearance, whereas anti-HBV therapy only marginally increased annual incidence of HBsAg loss.