HBV DNA Integration and Clonal Hepatocyte Expansion in Chronic Hepatitis B Patients Considered Immune Tolerant

Long-term antiviral therapy is associated with changes in the profile of transcriptionally active HBV integration in the livers of patients with CHB

Hepatitis B virus (HBV) integration exists throughout the clinical course of chronic hepatitis B (CHB). This study investigated the effects of long-term antiviral therapy on the level and profiles of transcriptionally active HBV integration. Serial liver biopsies and paired blood samples were obtained from 16, 16, and 22 patients with CHB at baseline, 78, and 260 weeks of entecavir monotherapy or combined with pegylated interferon alfa, respectively. Serum HBV biomarkers were longitudinally assessed. RNA-seq and HIVID2 program was used to identify HBV-host chimeric RNAs transcribed from integrated DNA. The counts of HBV integration reads were positively related to both serum HBV DNA levels (r = 0.695, p = 0.004) and HBeAg titers (r = 0.724, p = 0.021) at baseline, but the positive correlation exited only to the serum HBsAg levels after 260 weeks of antiviral therapy (r = 0.662, p = 0.001). After 78 weeks of antiviral therapy, the levels of HBV integration expression decreased by 12.25 folds from baseline. The viral junction points were enriched at the S and HBx genes after the long-term antiviral therapy. HBs-FN1 became one of the main transcripts, with the mean proportion of HBs-FN1 in all integrated expression increased from 2.79% at baseline to 10.54% at Week 260 of antiviral treatment. Antiviral therapy may reduce but not eliminate the HBV integration events and integration expression. Certain integration events, such as HBs-FN1 can persist in long-term antiviral treatment.

Treatment decisions based on HBV DNA

The most common cause of hepatocellular carcinoma (HCC) worldwide is chronic hepatitis B virus (HBV) infection (CHB). Long-term suppression of HBV replication by antiviral treatment reduces the risk of HCC and mortality. Nonetheless, only 2.2% of CHB patients globally received the treatment in 2019. Current international CHB guidelines recommend antiviral treatment only in subsets of patients with clear evidence of liver damage as evidenced by elevation of alanine aminotransferase (ALT). This review aims to provide existing evidence that the risk of HCC is significantly associated with serum levels of HBV DNA, and the association is non-linear parabolic, in both untreated and treated CHB patients, regardless of HBeAg status or ALT levels. Therefore, the decision for the antiviral treatment should be based on serum HBV DNA levels and age, rather than ALT levels or liver biopsy, to reduce or prevent the risk of HCC in CHB patients. The potential impact and cost-effectiveness data on early antiviral treatment initiation were also collated.

Restoration of CD3+CD56+ NKT-like cell function by TIGIT blockade in inactive carrier and immune tolerant patients of chronic hepatitis B virus infection

Chronic hepatitis B (CHB) virus infection, which can be divided into immune-tolerant (IT), immune-active (IA), inactive carrier (IC) phases, and HBeAg-negative hepatitis (ENEG), can induce liver cirrhosis and eventually hepatocellular carcinoma (HCC). CD3+CD56+ NKT-like cells play an important role in antiviral immune response. However, the mechanism of NKT-like cells to mediate immune tolerance remains largely elusive. In this study, we observed circulating NKT-like cells from IC and IT CHB patients were phenotypically and functionally impaired, manifested by increased expression of inhibitory receptor TIGIT and decreased capacity of secreting antiviral cytokines. Besides, TIGIT+ NKT-like cells of IC and IT CHB patients expressed lower levels of cytotoxic cytokines than the TIGIT- subset. Furthermore, increased expression of CD155, the ligand of TIGIT, on plasmacytoid dendritic cells (pDCs) was detected in IC and IT CHB patients. Importantly, the co-culture of NKT-like cells and pDCs showed that NKT-like cells restored their antiviral ability after TIGIT blockade upon HBV peptide stimulation in IC and IT CHB patients. In conclusion, our findings suggest that the TIGIT pathway may mediate immune tolerance in IT CHB patients and lead to functional impairment in IC patients, indicating that TIGIT may be a potential therapeutic checkpoint for immunotherapy of CHB patients.

Stat3 activation-triggered transcriptional networks govern the early stage of HBV-induced hepatic inflammation

The chronic carrier state of the hepatitis B virus (HBV) often leads to the development of liver inflammation as carriers age. However, the exact mechanisms that trigger this hepatic inflammation remain poorly defined. We analyzed the sequential processes during the onset of liver inflammation based on time-course transcriptome and transcriptional regulatory networks in an HBV transgenic (HBV-Tg) mice model and chronic HBV-infected (CHB) patients (data from GSE83148). The key transcriptional factor (TF) responsible for hepatic inflammation occurrence was identified and then validated both in HBV-Tg mice and liver specimens from young CHB patients. By time-course analysis, an early stage of hepatic inflammation was demonstrated in 3-month-old HBV-Tg mice: a marked upregulation of genes related to inflammation (Saa1/2, S100a8/9/11, or Il1β), innate immunity (Tlr2, Tlr7, or Tlr8), and cells chemotaxis (Ccr2, Cxcl1, Cxcl13, or Cxcl14). Within CHB samples, a unique early stage of inflammation activation was discriminated from immune tolerance and immune activation groups based on distinct gene expression patterns. Enhanced activation of TF Stat3 was strongly associated with increased inflammatory gene expression in this early stage of inflammation. Expression of phosphorylated Stat3 was higher in liver specimens from young CHB patients with relatively higher alanine aminotransferase levels. Specific inhibition of Stat3 activation significantly attenuated the degree of liver inflammation, the expression of inflammation-related genes, and the inflammatory monocytes and macrophages in 3-month-old HBV-Tg mice. Stat3 activation is essential for hepatic inflammation occurrence and is a novel indicator of early-stage immune activation in chronic HBV carriers.

IMPORTANCE

Until now, it remains a mystery that chronic hepatitis B virus (HBV)-infected patients in the "immune tolerance phase" will transition to the "immune activation phase" as they age. In this study, we reveal that Stat3 activation-triggered hepatic transcriptional alterations are distinctive characteristics of the early stage of immune/inflammation activation in chronic HBV infection. For the first time, we discover a mechanism that might trigger the transition from immune tolerance to immune activation in chronic HBV carriers.

Spatial transcriptomics reveals a low extent of transcriptionally active hepatitis B virus integration in patients with HBsAg loss

OBJECTIVE

Hepatitis B virus (HBV) can integrate into the chromosomes of infected hepatocytes, contributing to the production of hepatitis B surface antigen (HBsAg) and to hepatocarcinogenesis. In this study, we aimed to explore whether transcriptionally active HBV integration events spread throughout the liver tissue in different phases of chronic HBV infection, especially in patients with HBsAg loss.

DESIGN

We constructed high-resolution spatial transcriptomes of liver biopsies containing 13 059 tissue spots from 18 patients with chronic HBV infection to analyse the occurrence and relative distribution of transcriptionally active viral integration events. Immunohistochemistry was performed to evaluate the expression of HBsAg and HBV core antigen. Intrahepatic covalently closed circular DNA (cccDNA) levels were quantified by real-time qPCR.

RESULTS

Spatial transcriptome sequencing identified the presence of 13 154 virus-host chimeric reads in 7.86% (1026 of 13 059) of liver tissue spots in all patients, including three patients with HBsAg loss. These HBV integration sites were randomly distributed on chromosomes and can localise in host genes involved in hepatocarcinogenesis, such as ALB, CLU and APOB. Patients who were receiving or had received antiviral treatment had a significantly lower percentage of viral integration-containing spots and significantly fewer chimeric reads than treatment-naïve patients. Intrahepatic cccDNA levels correlated well with viral integration events.

CONCLUSION

Transcriptionally active HBV integration occurred in chronically HBV-infected patients at different phases, including in patients with HBsAg loss. Antiviral treatment was associated with a decreased number and extent of transcriptionally active viral integrations, implying that early treatment intervention may further reduce the number of viral integration events.

The dual role of regulatory T cells in hepatitis B virus infection and related hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a major contributor to cancer-related deaths worldwide. Hepatitis B virus (HBV) infection is a major etiologic factor leading to HCC. While there have been significant advancements in controlling HBV replication, achieving a complete cure for HBV-related HCC (HBV-HCC) remains an intricate challenge. HBV persistence is attributed to a myriad of mechanisms, encompassing both innate and adaptive immune responses. Regulatory T cells (Tregs) are pivotal in upholding immune tolerance and modulating excessive immune activation. During HBV infection, Tregs mediate specific T cell suppression, thereby contributing to both persistent infection and the mitigation of liver inflammatory responses. Studies have demonstrated an augmented expression of circulating and intrahepatic Tregs in HBV-HCC, which correlates with impaired CD8+ T cell function. Consequently, Tregs play a dual role in the context of HBV infection and the progression of HBV-HCC. In this comprehensive review, we discuss pertinent studies concerning Tregs in HBV infection, HBV-related cirrhosis and HCC. Furthermore, we summarize Treg responses to antiviral therapy and provide Treg-targeted therapies specific to HBV and HCC.

Addition of PEG-interferon to long-term nucleos(t)ide analogue therapy enhances HBsAg decline and clearance in HBeAg-negative chronic hepatitis B: Multicentre Randomized Trial (PAS Study)

We studied whether 48 weeks of PEG-IFN alfa-2a add-on increases HBsAg-decline and clearance in HBeAg-negative patients on long-term nucleo(s)tide analogue (NA) therapy. In this investigator-initiated, randomized, controlled trial conducted in Europe and Canada, HBeAg-negative patients treated with NA > 12 months, with HBVDNA < 200 IU/mL, were enrolled. Patients were randomized 2:1 to 48 weeks of PEG-IFN alfa-2a add-on (180 μg per week) or continued NA-monotherapy with subsequent follow-up to Week 72. Endpoints were HBsAg decline (≥1 log10 IU/mL) and HBsAg clearance at Week 48. Of the 86 patients in the modified-intention-to-treat analysis, 58 patients received PEG-IFN add-on, and 28 continued NA monotherapy. At Week 48, 16(28%) patients achieved HBsAg decline ≥1 log10 in the add-on arm versus none on NA-monotherapy (p < .001), and HBsAg clearance was observed in 6 (10%) PEG-IFN add-on patients versus 0% NA-monotherapy (p = .01). HBVRNA was only detected in 2% after PEG-IFN treatment versus 19% in NA-monotherapy (p = .002) at Week 48. PEG-IFN add-on therapy was well tolerated in majority of patients. Low baseline HBsAg levels (<10 IU/mL) identified patients most likely to achieve HBsAg loss with PEG-IFN add-on, whereas an HBsAg level > 200 IU/mL at on-treatment Week 12 was highly predictive of non-response (NPV = 100%). Addition of PEG-IFN to long-term NA enhanced HBsAg decline and increased the chance of HBsAg clearance in HBeAg-negative patients on long-term NA. On-treatment HBsAg levels >200 IU/mL identify patients unlikely to benefit from PEG-IFN add-on and could be used as a potential stopping-rule for PEG-IFN therapy. Our findings support further exploration of immune modulation add-on to antiviral therapy, preferably using response-guided strategies, to increase functional cure rates in patients with CHB.

Non-linear association of baseline viral load with on-treatment hepatocellular carcinoma risk in chronic hepatitis B

OBJECTIVE

The association between baseline pretreatment serum HBV DNA levels and on-treatment hepatocellular carcinoma (HCC) risk remains controversial in patients with chronic hepatitis B (CHB). We aimed to investigate the association between baseline HBV viral load and on-treatment HCC risk in CHB patients without cirrhosis.

DESIGN

Using a multicentre historical cohort study including 4693 hepatitis B e antigen (HBeAg)-negative and HBeAg-positive, adult CHB patients without cirrhosis who initiated antiviral treatment, HCC risk was estimated by baseline HBV viral load as a categorical variable.

RESULTS

During a median of 7.6 years of antiviral treatment, 193 patients developed HCC (0.53 per 100 person- years). Baseline HBV DNA level was independently associated with on-treatment HCC risk in a non-linear, parabolic pattern. Patients with moderate baseline viral loads (5.00-7.99 log10 IU/mL) exhibited the highest HCC risk (HR, 2.60; p<0.001), followed by those with low viral loads (3.30-4.99 log10 IU/mL; HR, 1.66; p=0.11). Patients with high viral loads (≥8.00 log10 IU/mL) presented the lowest HCC risk. Particularly, patients with baseline HBV DNA levels 6.00-6.99 log10 IU/mL had the highest on-treatment HCC risk (HR, 3.36; p<0.001) compared with those with baseline HBV DNA levels≥8.00 log10 IU/mL. These findings were more prominent among HBeAg-positive patients, younger patients, or those with less advanced hepatic fibrosis.

CONCLUSION

Patients with moderate baseline viral load, particularly around 6 log10 IU/mL, demonstrated the highest on-treatment HCC risk, despite long-term antiviral treatment. Early initiation of antiviral treatment, tailored to viral load, should be considered to minimise HCC risk in adult CHB patients without cirrhosis.

Juveniles, young adults, and infants with hepatitis B virus infection: A genomic study

Integration of hepatitis B virus (HBV) DNA into the human genome is recognized as an oncogenic factor and a barrier to hepatitis B cure. In the study, biopsy liver tissues were collected from adolescents and young adults with acute HBV infection younger than or equal to 35 years of age and from HBV-infected infant patients younger than or equal to 6 months of age. A high-throughput sequencing method was used to detect HBV DNA integration. Totally, 12 adolescents, young adults, and 6 infants were included. Among the 12 patients with acute HBV infection, immunohistochemical staining of intrahepatic hepatitis B surface antigen for all displayed negative results, and no HBV DNA integrants in the hepatocyte DNA were confirmed. All infant patients had elevated levels of alanine aminotransferase and high levels of serum HBV DNA. Numerous gene sites of hepatocyte DNA were integrated by HBV DNA for each infant patient, ranging from 120 to 430 integration sites. The fragile histidine triad gene was the high-frequency integrated site in the intragenic region for infant patients. In conclusion, hepatocyte DNA is integrated by HBV DNA in babies with active hepatitis B but seems seldom affected among adolescents and young adults with acute HBV infection. Infantile hepatitis B should be taken seriously considering abundant HBV DNA integration events.

Gray zone of hepatitis B virus infection

ABSTRACT

A substantial proportion of patients with chronic hepatitis B (CHB) do not fall into any of the defined phases and are considered to be in the "gray zone" or "indeterminate phase." Most of the current clinical practice guidelines have no recommendations for antiviral treatment for them. However, the gray zone CHB patients with significant hepatitis B virus levels (>2000 IU/mL) and persistently normal alanine aminotransferase (ALT) levels have a significantly high risk of hepatic inflammation, fibrosis, and hepatocellular carcinoma. The molecular, clinical, and economic data that we have reviewed collectively in this article provide support for simplification of treatment initiation strategies that incorporate broader treatment of adult patients with CHB in the gray zone (hepatitis B virus [HBV] DNA ≥2000 IU/mL), regardless of ALT levels.

Review of Related Factors for Persistent Risk of Hepatitis B Virus-Associated Hepatocellular Carcinoma

Chronic hepatitis B virus (HBV) infection is the largest global cause of hepatocellular carcinoma (HCC). Current HBV treatment options include pegylated interferon-alpha and nucleos(t)ide analogues (NAs), which have been shown to be effective in reducing HBV DNA levels to become undetectable. However, the literature has shown that some patients have persistent risk of developing HCC. The mechanism in which this occurs has not been fully elucidated. However, it has been discovered that HBV's covalently closed circular DNA (cccDNA) integrates into the critical HCC driver genes in hepatocytes upon initial infection; additionally, these are not targets of current NA therapies. Some studies suggest that HBV undergoes compartmentalization in peripheral blood mononuclear cells that serve as a sanctuary for replication during antiviral therapy. The aim of this review is to expand on how patients with HBV may develop HCC despite years of HBV viral suppression and carry worse prognosis than treatment-naive HBV patients who develop HCC. Furthermore, HCC recurrence after initial surgical or locoregional treatment in this setting may cause carcinogenic cells to behave more aggressively during treatment. Curative novel therapies which target the life cycle of HBV, modulate host immune response, and inhibit HBV RNA translation are being investigated.

Risk of hepatitis B virus reactivation and its effect on survival in advanced hepatocellular carcinoma patients treated with hepatic arterial infusion chemotherapy and lenvatinib plus programmed death receptor-1 inhibitors

Background

Hepatitis B virus (HBV) reactivation is a common complication in hepatocellular carcinoma (HCC) patients treated with chemotherapy or immunotherapy. This study aimed to evaluate the risk of HBV reactivation and its effect on survival in HCC patients treated with HAIC and lenvatinib plus PD1s.

Methods

We retrospectively collected the data of 213 HBV-related HCC patients who underwent HAIC and lenvatinib plus PD1s treatment between June 2019 to June 2022 at Sun Yat-sen University, China. The primary outcome was the risk of HBV reactivation. The secondary outcomes were overall survival (OS), progression-free survival (PFS), and treatment-related adverse events.

Results

Sixteen patients (7.5%) occurred HBV reactivation in our study. The incidence of HBV reactivation was 5% in patients with antiviral prophylaxis and 21.9% in patients without antiviral prophylaxis, respectively. The logistic regression model indicated that for HBV reactivation, lack of antiviral prophylaxis (P=0.003) and tumor diameter (P=0.036) were independent risk factors. The OS and PFS were significantly shorter in the HBV reactivation group than the non-reactivation group (P=0.0023 and P=0.00073, respectively). The number of AEs was more in HBV reactivation group than the non-reactivation group, especially hepatic AEs.

Conclusion

HBV reactivation may occur in HCC patients treated with HAIC and lenvatinib plus PD1s. Patients with HBV reactivation had shorter survival time compared with non-reactivation. Therefore, HBV-related HCC patients should undergo antiviral therapy and HBV-DNA monitoring before and during the combination treatment.

Chronic hepatitis B baseline viral load and on-treatment liver cancer risk: A multinational cohort study of HBeAg-positive patients

BACKGROUND AND AIMS

A single-nation study reported that pretreatment HBV viral load is associated with on-treatment risk of HCC in patients who are HBeAg-positive without cirrhosis and with chronic hepatitis B initiating antiviral treatment. We aimed to validate the association between baseline HBV viral load and on-treatment HCC risk in a larger, multinational cohort.

APPROACH AND RESULTS

Using a multinational cohort from Korea, Hong Kong, and Taiwan involving 7545 adult patients with HBeAg-positive, without cirrhosis and with chronic hepatitis B who started entecavir or tenofovir treatment with baseline HBV viral load ≥5.00 log 10 IU/mL, HCC risk was estimated by baseline viral load. HBV viral load was analyzed as a categorical variable. During continuous antiviral treatment (median, 4.28 y), HCC developed in 200 patients (incidence rate, 0.61 per 100 person-years). Baseline HBV DNA level was independently associated with on-treatment HCC risk in a nonlinear pattern. HCC risk was lowest with the highest baseline viral load (≥8.00 log 10 IU/mL; incidence rate, 0.10 per 100 person-years), but increased sharply as baseline viral load decreased. The adjusted HCC risk was 8.05 times higher (95% CI, 3.34-19.35) with baseline viral load ≥6.00 and <7.00 log 10 IU/mL (incidence rate, 1.38 per 100 person-years) compared with high (≥8.00 log 10 IU/mL) baseline viral load ( p <0.001).

CONCLUSIONS

In a multinational cohort of adult patients with HBeAg-positive without cirrhosis and with chronic hepatitis B, baseline HBV viral load was significantly associated with HCC risk despite antiviral treatment. Patients with the highest viral load who initiated treatment had the lowest long-term risk of HCC development.

Updates on Systemic Therapy for Hepatocellular Carcinoma

This review explores the dynamic landscape of hepatocellular carcinoma (HCC) treatment, emphasizing on recent developments across various stages and therapeutic approaches. Although curative strategies such as hepatectomy and thermal ablation are standard for early-stage cases, high relapse rates drive investigations into adjuvant and perioperative treatment. Adjuvant therapies face hurdles, but noteworthy advances include IMbrave050 setting a new standard with atezolizumab/bevacizumab. Locoregional treatments gain significance, especially for multifocal HCC, with the integration of innovative combinations with systemic therapies, showing improved outcomes. In the advanced setting, the evolution from sorafenib as the primary first-line option to new standards, such as atezolizumab/bevacizumab and tremelimumab/durvalumab, to other emerging therapies such as tislelizumab and pembrolizumab with lenvatinib, is explored. Additionally, second-line treatments and insights into the interplay between immunotherapies and antiangiogenic agents, as well as novel combination strategies that add complexity to treatment decisions, are discussed.

Antiviral Therapy Favors a Lower Risk of Liver Cirrhosis in HBeAg-negative Chronic Hepatitis B with Normal Alanine Transaminase and HBV DNA Positivity

Background and Aims

Direct evidence on the outcomes of hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (CHB) patients with normal alanine transaminase after long-term antiviral treatment is lacking.

Methods

HBeAg-negative patients with normal ALT and positive HBV DNA (≥20 IU/mL) were retrospectively enrolled. The endpoints included virological response (HBV DNA<100 IU/mL), changes in aspartate aminotransferase to platelet ratio index (APRI) and fibrosis-4 index (FIB-4), and the incidence of liver nodules, cirrhosis, and hepatocellular carcinoma (HCC).

Results

This cohort (n=194) was divided into three subgroups, untreated (n=67), treatment-continued (n=87), and treatment-discontinued patients (n=40), with a median follow-up of 54 months. The treatment-continued group achieved 100% (95% CI: 94.7-100) virological response, and significantly reduced APRI and FIB-4 scores (both p<0.001). The risk of liver nodules and cirrhosis in that group was reduced by 76% (HR: 0.24, 95% CI: 0.11-0.54, p<0.001) and 89% (HR: 0.11, 95% CI: 0.14-0.91, p=0.041) vs. the untreated group and by 77% (HR: 0.23, 95% CI: 0.10-0.49, p<0.001) and 95% (HR: 0.05, 95% CI: 0.01-0.44, p=0.006) vs. the treatment-discontinued group. For patients with HBV DNA≥2,000 IU/mL, adherence to treatment lowered the risks of liver cirrhosis by 92% (95% CI: 0.01-0.67) and 93% (95% CI: 0.01-0.53) vs. the untreated and treatment-discontinued patients, respectively. No patient adhering to treatment developed HCC, but one in each of the remaining groups did.

Conclusions

Continuous nucleos(t)ide analog (NA) treatment has a satisfactory effectiveness and helps to lower the risk of liver cirrhosis in HBeAg-negative CHB patients with normal alanine transaminase, especially in those with HBV DNA≥2,000 IU/mL.

Efficacy of pegylated interferon α-2b plus entecavir therapy and predictors of treatment success in children with chronic hepatitis B

Introduction

Interferon therapy, used in the treatment of chronic hepatitis B (CHB), is one of the means by which patients can achieve a functional cure. Pegylated interferon is currently used in the treatment of CHB. There are two main types of pegylated interferon: α-2b and α-2a.

Methods

This study explored the efficacy, safety, and predictors of treatment response for α-2b plus entecavir among children in a real-world setting.

Results

The study included 76 patients aged 3-18 years, all of whom were treated with interferon α-2b plus entecavir. The mean duration of treatment was 401.99 days, and 31.6% (24/76) of patients achieved HBsAg clearance. Competing risk model analyses showed that children with baseline HBsAg <1500 IU/mL (subdistribution hazard ratio [sHR]=2.643, P=0.022) and a higher baseline alanine aminotransferase (ALT) level (sHR=1.005, P=0.000) had a higher probability of achieving HBsAg clearance during treatment. Conversely, children with a higher hepatitis B virus loading level (sHR=0.835, P=0.043) and age ≥10 years (sHR=0.243, P=0.002) had a lower probability of achieving HBsAg clearance during treatment. A decrease of >1 log10 in HBsAg level (sHR=3.479, P=0.001) at 12 weeks of treatment was associated with a higher probability of achieving surface antigen clearance.

Discussion

These results indicated that interferon plus entecavir therapy is a promising means of achieving HBsAg clearance in children with CHB. Moreover, HBsAg, ALT, virus loading, and age are indicators of treatment success probability.

A new approach to prevent, diagnose, and treat hepatitis B in Africa

There are 82 million people living with hepatitis B (PLWHB) in the World Health Organization Africa region, where it is the main cause of liver disease. Effective vaccines have been available for over 40 years, yet there are 990,000 new infections annually, due to limited implementation of hepatitis B birth dose vaccination and antenatal tenofovir prophylaxis for highly viraemic women, which could eliminate mother-to-child transmission. Despite effective and cheap antiviral treatment which can suppress hepatitis B virus replication and reduce the risk of hepatocellular carcinoma (HCC), < 2% of PLWHB are diagnosed, and only 0.1% are treated. As a result, PLWHB are frequently diagnosed only when they have already developed decompensated cirrhosis and late-stage HCC, and consequently 80,000 hepatitis B-associated deaths occur each year. Major barriers include complex treatment guidelines which were derived from high-income settings, lack of affordable diagnostics, lack or insufficient domestic funding for hepatitis care, and limited healthcare infrastructure. Current treatment criteria may overlook patients at risk of cirrhosis and HCC. Therefore, expanded and simplified treatment criteria are needed. We advocate for decentralized community treatment programmes, adapted for low-resource and rural settings with limited laboratory infrastructure. We propose a strategy of treat-all except patients fulfilling criteria that suggest low risk of disease progression. Expanded treatment represents a financial challenge requiring concerted action from policy makers, industry, and international donor agencies. It is crucial to accelerate hepatitis B elimination plans, integrate hepatitis B care into existing healthcare programmes, and prioritize longitudinal and implementation research to improve care for PLWHB.

Efficacy and Safety of Antiviral Therapy for Immune-tolerant Hepatitis B Viral Infection in Children: A Systematic Review and Meta-analysis

BACKGROUND

Chronic hepatitis B virus (HBV) infection burden in children remains a pressing public health concern. Whether antiviral therapy should be administered to children with HBV in the immune-tolerant phase remains controversial. We performed a meta-analysis to evaluate antiviral therapy efficacy and safety in children with immune-tolerant hepatitis B (ITHB).

METHODS

A search was conducted in multiple databases (PubMed, Embase, Cochrane, Web of Science, CBM, CNKI and Wanfang Data) to identify clinical trials examining antiviral therapy efficacy and safety in children (1-18 years) with ITHB viral infection from inception to February 2023. Outcomes were calculated separately for controlled and single-arm studies.

RESULTS

Nine trials (442 patients), including 2 randomized controlled trials (RCTs), 3 non-RCTs and 4 single-arm studies, were included in this meta-analysis. In the RCTs, antiviral therapy group exhibited greater rates of HBsAg loss [risk ratio (RR) = 6.11, 95% confidence interval (CI): 1.67-22.31, P Z-test = 0.006], HBsAg serologic response (RR = 5.29, 95% CI: 1.47-19.07, P Z-test = 0.011) and HBeAg loss (RR = 3.00, 95% CI: 1.35-6.66, P Z-test = 0.007) compared with the control group at the end of follow-up. In single-arm studies, the pooled incidences of HBsAg loss, HBeAg loss and HBsAg seroconversion were 24% (95% CI: -0.1% to 48%), 24% (95% CI: -0.1% to 48%) and 24% (95% CI: -5% to 52%), respectively.

CONCLUSION

Current evidence suggests the effectiveness of antiviral therapy in children with HBV infection in the immune-tolerant stage, with few serious adverse events. Due to the limited quality and number of included studies, more high-quality studies are required to validate our findings.

Chronic Hepatitis B: Treat all Who Are Viremic?

The main aim of antiviral therapy in patients with chronic hepatitis B (CHB) is to prevent disease progression and reduce the risk of hepatocellular carcinoma (HCC). In general, treatment is recommended for select patient groups viewed as being at higher risk of developing adverse outcomes from CHB. However, patients who do not meet treatment criteria under current international guidelines may still benefit from antiviral therapy to reduce CHB-related complications. Moreover, well-tolerated antiviral drugs that are highly effective at suppressing viral replication are now widely available, and withholding therapy from patients with viremia is increasingly controversial. In this article, we review traditional treatment paradigms and argue the merits of expanding treatment eligibility to patients with CHB who do not meet current treatment criteria.

What Is the Current Status of Hepatitis B Virus Viro-Immunology?

The natural history of hepatitis B virus (HBV) infection is closely dependent on the dynamic interplay between the host immune response and viral replication. Spontaneous HBV clearance in acute self-limited infection is the result of an adequate and efficient antiviral immune response. Instead, it is widely recognized that in chronic HBV infection, immunologic dysfunction contributes to viral persistence. Long-lasting exposure to high viral antigens, upregulation of multiple co-inhibitory receptors, dysfunctional intracellular signaling pathways and metabolic alterations, and intrahepatic regulatory mechanisms have been described as features ultimately leading to a hierarchical loss of effector functions up to full T-cell exhaustion.

Functional Cure of Chronic Hepatitis B with Antiviral Treatment in Children having High-level Viremia and Normal or Mildly Elevated Serum Aminotransferase

Background and Aims

There is a lack of data supporting the notion that antiviral treatments can benefit children with chronic hepatitis B (CHB) having high viremia and normal or mildly elevated serum alanine aminotransferase (ALT) levels. We aimed to analyze the efficacy of antiviral treatments in children with CHB and explore the factors associated with functional cure.

Methods

Forty-eight children with CHB having high viremia and normal or mildly elevated serum ALT levels were screened in this real-world study. Thirty-two children received either interferon-alpha (IFN-α) monotherapy, IFN-α therapy with a nucleoside analog (NA) add-on, or IFN-α and NA combination therapy. The 16 children in the control group did not receive antiviral treatment. All 48 children were available for follow-up assessments for the entire 36-month study period. We identified a functional cure with respect to hepatitis B virus (HBV) DNA loss, loss /seroconversion of circulating hepatitis B e antigen (HBeAg), and loss of hepatitis B surface antigen (HBsAg) with or without seroconversion. Cox regression analysis was employed to evaluate the factors that may have influenced the functional cure.

Results

After 36 months, the cumulative functional cure rate was 56.25% (18/32) in the treated group and 0% (0/16) in the control group (p<0.001). In the treated group, the serum HBV DNA levels declined rapidly at the end of a 6-month visit and the cured children achieved a loss rate of 100% (18/18) within 16 months of beginning treatment, compared with 64.29% (9/14) of the uncured children (p<0.001). The rates of HBeAg seroconversion were significantly higher among the cured children than among the uncured children (p<0.001). All 16 children in the control group maintained high levels of serum HBV DNA and were positive for both serum HBeAg and HBsAg during the entire 36 months of the study period. Functional cure was associated with younger ages (1-6 vs. 7-14 years, p=0.013), CD8+ T lymphocyte counts (p=0.013), and B lymphocyte counts (p=0.003). No serious adverse events were observed.

Conclusions

Antiviral treatment achieved a functional cure of CHB in a high proportion of children having high-level viremia and normal or mildly elevated ALT levels. Younger age and high peripheral lymphocyte counts were associated with this functional cure.

Hepatitis B surface antigen reduction is associated with hepatitis B core-specific CD8+ T cell quality

Despite treatment, hepatitis B surface antigen (HBsAg) persists in patients with chronic hepatitis B (CHB), suggesting the likely presence of the virus in the body. CD8+ T cell responses are essential for managing viral replication, but their effect on HBsAg levels remains unclear. We studied the traits of activated CD8+ T cells and HBV-specific CD8+ T cells in the blood of CHB patients undergoing nucleos(t)ide analog (NUC) therapy. For the transcriptome profiling of activated CD8+ T cells in peripheral blood mononuclear cells (PBMCs), CD69+ CD8+ T cells were sorted from six donors, and single-cell RNA sequencing (scRNA-seq) analysis was performed. To detect HBV-specific CD8+ T cells, we stimulated PBMCs from 26 donors with overlapping peptides covering the HBs, HBcore, and HBpol regions of genotype A/B/C viruses, cultured for 10 days, and analyzed via multicolor flow cytometry. scRNA-seq data revealed that CD8+ T cell clusters harboring the transcripts involved in the cytolytic functions were frequently observed in donors with high HBsAg levels. Polyfunctional analysis of HBV-specific CD8+ T cells utilized by IFN-γ/TNFα/CD107A/CD137 revealed that HBcore-specific cells exhibited greater polyfunctionality, suggesting that the quality of HBV-specific CD8+ T cells varies among antigens. Moreover, a subset of HBcore-specific CD8+ T cells with lower cytolytic potential was inversely correlated with HBsAg level. Our results revealed a stimulant-dependent qualitative difference in HBV-specific CD8+ T cells in patients with CHB undergoing NUC therapy. Hence, the induction of HBcore-specific CD8+ T cells with lower cytolytic potential could be a new target for reducing HBsAg levels.

Integration of Viral Genome to Human Genomic DNA in Nails of Patients with Chronic Hepatitis B Virus Infection

Introduction

Hepatitis B virus (HBV) DNA and cytomegalovirus (CMV) DNA can be detected in patient genomes. However, it remains unknown whether viral DNA can be integrated into host genomic DNA and detected in fingernails.

Methods

Nails from patients with chronic HBV infection were investigated. A total of 60 patients (male/female = 20/40, age range from 2 years to 59 years, median 15 years) were included in this study. The viral DNA levels of herpes simplex virus 1 (HSV-1), herpes simplex virus 2 (HSV-2), varicella-zoster virus (VZV), Epstein‒Barr virus (EBV), cytomegalovirus (CMV), human herpes virus 6 (HHV-6), human herpes virus 7 (HHV-7), and HBV in nails were measured with real-time PCR. Viral DNA integration into host genomic DNA was analyzed by capture-based next-generation sequencing (NGS). Moreover, virus/host chimeric sequences, which were detected by capture-based NGS, were confirmed by Sanger sequencing.

Results

Of the 60 patients, 37 (62%) were positive for nail HBV DNA. All 60 patients were negative for nail HSV-1, HSV-2, VZV, CMV, EBV, or HHV-6 DNA. However, three patients were positive for nail HHV-7 DNA. All three nail HHV-7-positive patients were also positive for nail HBV DNA. The three nail samples that were positive for both HBV and HHV-7 DNA were used for viral integration analysis by capture-based NGS. One of the three nail samples showed HBV/host chimeric sequences. In addition, all three nail samples showed HHV-7/host chimeric sequences. However, these viral integration breakpoints were not confirmed by Sanger sequencing.

Conclusions

Viral integrations were detected in nails by capture-based NGS. However, Sanger sequencing did not confirm any virus/host chimeric sequences. This study could not show reliable evidence of viral integration in nails.

Hepatocellular Carcinoma and Hepatitis: Advanced Diagnosis and Management with a Focus on the Prevention of Hepatitis B-Related Hepatocellular Carcinoma

Though the world-wide hepatitis B virus (HBV) vaccination program has been well completed for almost thirty years in many nations, almost HBV-related hepatocellular carcinoma (HCC) occurs in unvaccinated middle-aged and elderly adults. Apparently, treating 80% of qualified subjects could decrease HBV-related mortality by 65% in a short period. Nevertheless, globally, only 2.2% of CHB patients undergo antiviral therapy. The HBV markers related to HCC occurrence and prevention are as follows: the HCC risk is the highest at a baseline of HBV DNA of 6-7 log copies/mL, and it is the lowest at a baseline of an HBV DNA level of >8 log copies/mL and ≤4 log copies/mL (parabolic, and not linear pattern). The titer of an HBV core-related antigen (HBcrAg) reflecting the amount of HBV covalently closed circular DNA (ccc DNA) in the liver is related to HCC occurrence. The seroclearance of HBs antigen (HBsAg) is more crucial than HBV DNA negativity for the prevention of HCC. In terms of the secondary prevention of hepatitis B-related HCC involving antiviral therapies with nucleos(t)ide analogues (NAs), unsolved issues include the definition of the immune-tolerant phase; the optimal time for starting antiviral therapies with NAs; the limits of increased aminotransferase (ALT) levels as criteria for therapy in CHB patients; the normalization of ALT levels with NAs and the relation to the risk of HCC; and the relation between serum HBV levels and the risk of HCC. Moreover, the first-line therapy with NAs including entecavir (ETV), tenofovir disoproxil fumarate (TDF), and tenofovir alafenamide (TAF) remains to be clarified. Discussed here, therefore, are the recent findings of HBV markers related to HCC occurrence and prevention, unsolved issues, and the current secondary antiviral therapy for the prevention of HBV-related HCC.

The Initial Hepatitis B Virus-Hepatocyte Genomic Integrations and Their Role in Hepatocellular Oncogenesis

Hepatitis B virus (HBV) remains a dominant cause of hepatocellular carcinoma (HCC). Recently, it was shown that HBV and woodchuck hepatitis virus (WHV) integrate into the hepatocyte genome minutes after invasion. Retrotransposons and transposable sequences were frequent sites of the initial insertions, suggesting a mechanism for spontaneous HBV DNA dispersal throughout the hepatocyte genome. Several somatic genes were also identified as early insertional targets in infected hepatocytes and woodchuck livers. Head-to-tail joints (HTJs) dominated amongst fusions, indicating their creation by non-homologous end-joining (NHEJ). Their formation coincided with the robust oxidative damage of hepatocyte DNA. This was associated with the activation of poly(ADP-ribose) polymerase 1 (PARP1)-mediated dsDNA repair, as reflected by the augmented transcription of PARP1 and XRCC1; the PARP1 binding partner OGG1, a responder to oxidative DNA damage; and increased activity of NAD+, a marker of PARP1 activation, and HO1, an indicator of cell oxidative stress. The engagement of the PARP1-mediated NHEJ repair pathway explains the HTJ format of the initial merges. The findings show that HBV and WHV are immediate inducers of oxidative DNA damage and hijack dsDNA repair to integrate into the hepatocyte genome, and through this mechanism, they may initiate pro-oncogenic processes. Tracking initial integrations may uncover early markers of HCC and help to explain HBV-associated oncogenesis.

Pathway to global elimination of hepatitis B: HBV cure is just the first step

Hepatitis B (HBV) is a major cause of global morbidity and mortality, and the leading cause of liver cancer worldwide. Significant advances have recently been made toward the development of a finite HBV treatment that achieves permanent loss of HBsAg and HBV DNA (so-called "HBV cure"), which could provide the means to eliminate HBV as a public health threat. However, the HBV cure is just one step toward achieving WHO HBV elimination targets by 2030, and much work must be done now to prepare for the successful implementation of the HBV cure. In this review, we describe the required steps to rapidly scale-up future HBV cure equitably. We present key actions required for successful HBV cure implementation, integrated within the World Health Organization (WHO) Global Health Sector Strategy (GHSS) 2022-2030 framework. Finally, we highlight what can be done now to progress toward the 2030 HBV elimination targets using available tools to ensure that we are preparing, but not waiting, for the cure.

Chronic Hepatitis B Infection: New Approaches towards Cure

Chronic hepatitis B virus (HBV) infection leads to the development of cirrhosis and hepatocellular carcinoma. Lifelong treatment with nucleotides/nucleoside antiviral agents is effective at suppressing HBV replication, however, adherence to daily therapy can be challenging. This review discusses recent advances in the development of long-acting formulations for HBV treatment and prevention, which could potentially improve adherence. Promising new compounds that target distinct steps of the virus life cycle are summarized. In addition to treatments that suppress viral replication, curative strategies are focused on the elimination of covalently closed circular DNA and the inactivation of the integrated viral DNA from infected hepatocytes. We highlight promising long-acting antivirals and genome editing strategies for the elimination or deactivation of persistent viral DNA products in development.

Developments in pharmacotherapeutic agents for hepatitis B - how close are we to a functional cure?

INTRODUCTION

Hepatitis B virus (HBV) remains a public health concern given its global prevalence and potential complications including hepatocellular carcinoma (HCC). Current therapies, including nucleos(t)ide analogs (NA) and interferons (IFN), are effective in chronic treatment of HBV but rarely provide a functional cure due to inadequate host response and the presence of viral DNA. Therefore, novel therapies that enhance the innate immune response while suppressing DNA transcription may provide definitive treatment of HBV.

AREAS COVERED

In this review, the authors provide a brief overview of commonly used agents and their efficacy in treatment of HBV. Newer therapies with direct antiviral agents such as bepirovirsen (antisense oligonucleotide (ASO)) and entry inhibitors such as bulevirtide have shown efficacy in reducing viral load but demonstrate further reductions in conjunction with immune modulators such as therapeutic vaccines.

EXPERT OPINION

Combination therapy is far superior to monotherapy alone, necessitating the need for both immunomodulators and direct antiviral agents in chronic treatment of HBV. Therapies that target covalently closed circular (cccDNA) with immunomodulators like therapeutic vaccines have shown promising results and may ultimately achieve functional cure. However, therapies need to be evaluated in the context of the patient, considering both financial and socioeconomic factors.

HBV Infection and Host Interactions: The Role in Viral Persistence and Oncogenesis

Hepatitis B virus (HBV) is a major cause of chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. Despite the advent of vaccines and potent antiviral agents able to suppress viral replication, recovery from chronic HBV infection is still an extremely difficult goal to achieve. Complex interactions between virus and host are responsible for HBV persistence and the risk of oncogenesis. Through multiple pathways, HBV is able to silence both innate and adaptive immunological responses and become out of control. Furthermore, the integration of the viral genome into that of the host and the production of covalently closed circular DNA (cccDNA) represent reservoirs of viral persistence and account for the difficult eradication of the infection. An adequate knowledge of the virus-host interaction mechanisms responsible for viral persistence and the risk of hepatocarcinogenesis is necessary for the development of functional cures for chronic HBV infection. The purpose of this review is, therefore, to analyze how interactions between HBV and host concur in the mechanisms of infection, persistence, and oncogenesis and what are the implications and the therapeutic perspectives that follow.

Evidence for Benefits of Early Treatment Initiation for Chronic Hepatitis B

Chronic hepatitis B (CHB) is the most common cause of hepatocellular carcinoma (HCC) worldwide. Antiviral treatment reduces the risk of HCC and mortality; nonetheless, globally in 2019, only 2.2% of CHB patients received treatment. Current international CHB guidelines recommend antiviral treatment only in subsets of patients with clear evidence of liver damage. This contrasts with hepatitis C or HIV where early treatment is recommended in all infected patients, regardless of end-organ damage. This narrative review aims to provide an overview of data on the early initiation of antiviral treatment and its related potential economic impact. Literature searches were performed using PubMed and abstracts from international liver congresses (2019-2021). Data on risk of disease progression and HCC and the impact of antiviral treatment in currently ineligible patients were summarized. Cost-effectiveness data on early antiviral treatment initiation were also collated. Accumulating molecular, clinical, and economic data suggest that early initiation of antiviral treatment could save many lives through HCC prevention in a highly cost-effective manner. In light of these data, we consider several alternative expanded treatment strategies that might further a simplified 'treatment as prevention' approach.

Intrahepatic quantification of HBV antigens in chronic hepatitis B reveals heterogeneity and treatment-mediated reductions in HBV core-positive cells

Background & Aims

Patterns of liver HBV antigen expression have been described but not quantified at single-cell resolution. We applied quantitative techniques to liver biopsies from individuals with chronic hepatitis B and evaluated sampling heterogeneity, effects of disease stage, and nucleos(t)ide (NUC) treatment, and correlations between liver and peripheral viral biomarkers.

Methods

Hepatocytes positive for HBV core and HBsAg were quantified using a novel four-plex immunofluorescence assay and image analysis. Biopsies were analysed from HBeAg-positive (n = 39) and HBeAg-negative (n = 75) participants before and after NUC treatment. To evaluate sampling effects, duplicate biopsies collected at the same time point were compared. Serum or plasma samples were evaluated for levels of HBV DNA, HBsAg, hepatitis B core-related antigen (HBcrAg), and HBV RNA.

Results

Diffusely distributed individual HBV core+ cells and foci of HBsAg+ cells were the most common staining patterns. Hepatocytes positive for both HBV core and HBsAg were rare. Paired biopsies revealed large local variation in HBV staining within participants, which was confirmed in a large liver resection. NUC treatment was associated with a >100-fold lower median frequency of HBV core+ cells in HBeAg-positive and HBeAg-negative participants, whereas reductions in HBsAg+ cells were not statistically significant. The frequency of HBV core+ hepatocytes was lower in HBeAg-negative participants than in HBeAg-positive participants at all time points evaluated. Total HBV+ hepatocyte burden correlated with HBcrAg, HBV DNA, and HBV RNA only in baseline HBeAg-positive samples.

Conclusions

Reductions in HBV core+ hepatocytes were associated with HBeAg-negative status and NUC treatment. Variation in HBV positivity within individual livers was extensive. Correlations between the liver and the periphery were found only between biomarkers likely indicative of cccDNA (HBV core+ and HBcrAg, HBV DNA, and RNA).

Impact and Implications

HBV infects liver hepatocyte cells, and its genome can exist in two forms that express different sets of viral proteins: a circular genome called cccDNA that can express all viral proteins, including the HBV core and HBsAg proteins, or a linear fragment that inserts into the host genome typically to express HBsAg, but not HBV core. We used new techniques to determine the percentage of hepatocytes expressing the HBV core and HBsAg proteins in a large set of liver biopsies. We find that abundance and patterns of expression differ across patient groups and even within a single liver and that NUC treatment greatly reduces the number of core-expressing hepatocytes.

Effect of Antiviral Treatment on Hepatitis B Virus Integration and Hepatocyte Clonal Expansion

BACKGROUND

This study investigated the effect of nucleos(t)ide analogue (NUC) treatment on hepatitis B virus (HBV) DNA integration and hepatocyte clonal expansion, both of which are implicated in hepatocellular carcinoma (HCC) in chronic hepatitis B.

METHODS

Twenty-eight patients receiving NUCs (11 lamivudine, 7 telbivudine, 10 entecavir) were included. All had liver biopsies at baseline and year 1, and 7 had a third biopsy at year 10. HBV DNA integration and hepatocyte clone size were assessed by inverse polymerase chain reaction.

RESULTS

All patients had detectable HBV integration at baseline, with a median integration frequency of 1.01 × 109 per liver and hepatocyte clone size of 2.41 × 105. Neither integration frequency nor hepatocyte clone size correlated with age and HBV virologic parameters. After 1 year of treatment, HBV integration was still detectable in all patients, with a median of 5.74 × 108 integration per liver (0.22 log reduction; P = .008) and hepatocyte clone size of 1.22 × 105 (0.40 log reduction; P = .002). HBV integration remained detectable at year 10 of treatment, with a median integration frequency of 4.84 × 107 integration per liver (0.93 log reduction from baseline) and hepatocyte clone size of 2.55 × 104 (1.02 log reduction from baseline). From baseline through year 1 to year 10, there was a decreasing trend in both integration frequency and hepatocyte clone size (P = .066 and.018, respectively).

CONCLUSIONS

NUCs reduced both HBV DNA integration and hepatocyte clonal expansion, suggesting another alternative pathway besides direct viral suppression to reduce HCC risk. Our findings supported the notion for a long-term NUC treatment to prevent HCC.

Comparable outcomes between immune-tolerant and active phases in noncirrhotic chronic hepatitis B: a meta-analysis

BACKGROUND

Antiviral therapy is not indicated for patients with chronic hepatitis B (CHB) in the immune-tolerant (IT) phase. We compared the outcomes between the untreated IT phase and the treated immune-active (IA) phase in noncirrhotic HBeAg-positive CHB patients.

METHODS

We systematically searched 4 databases, including PubMed, Medline, Embase, and Cochrane, until August 2021. The pooled incidence rates of HCC and mortality in the IT and IA cohorts and phase change in the IT cohort were investigated. Studies that included patients with liver cirrhosis were excluded.

RESULTS

Thirteen studies involving 11,903 patients were included. The overall median of the median follow-up period was 62.4 months. The pooled 5-year and 10-year incidence rates of HCC were statistically similar between the IT and IA cohorts (1.1%, 95% CI: 0.4%-2.8% vs. 1.1%, 95% CI: 0.5%-2.3%, and 2.7%, 95% CI: 1.0%-7.3% vs. 3.6%, 95% CI: 2.4%-5.5%, respectively, all p>0.05). The pooled 5-year odds ratio of HCC between IT and IA cohorts was 1.05 (95% CI: 0.32-3.45; p=0.941). The pooled 5-year incidence rate of mortality was statistically similar between the IT and IA cohorts (1.9%, 95% CI: 1.1%-3.4% vs. 1.0%, 95% CI: 0.3%-2.9%, p=0.285). Finally, the pooled 5-year incidence rate of phase change in the IT cohort was 36.1% (95% CI: 29.5%-43.2%).

CONCLUSION

The pooled incidence rates of HCC and mortality were comparable between the untreated IT and the treated IA phases in noncirrhotic HBeAg-positive CHB patients.

Therapies against chronic hepatitis B infections: The times they are a-changin', but the changing is slow!

PREAMBULAR NOTA BENE

As a tribute to Dr Mike Bray, the following review of literature willbe mainly based on published data andconcepts, but will also contain my personal views, and in this respect could be more considered as a bioassay. Even though a cost-effective and excellent prophylactic vaccine exists since many years to protect against hepatitis B virus (HBV) infection, academic-researcher/drug-developers/stakeholders are still busy with the R&D of novel therapies that could eventually have an impact on its worldwide incidence. The Taiwanese experience have univocally demonstrated the effectiveness of constrained national HBV prophylactic vaccination programs to prevent the most dramatic HBV-induced end-stage liver disease, which is hepatocellular carcinoma; but yet the number of individuals chronically infected with the virus, for whom the existing prophylactic vaccine is no longer useful, remains high, with around 300 million individuals around the globe. In this review/bioassay, recent findings and novel concepts on prospective therapies against HBV infections will be discussed; yet it does not have the pretention to be exhaustive, as "pure immunotherapeutic concepts" will be mainly let aside (or referred to other reviews) due to a lack of expertise of this writer, but also due to the lack of, or incremental, positive results in clinical trials as-off today with these approaches.

Histologic changes in immune-tolerant patients with chronic hepatitis B: a systematic review and meta-analysis

The serological diagnostic criteria for the immune-tolerant (IT) phase have not been strictly defined and it is hard to determine an accurate rate for significant histologic changes among IT patients. The aim of this study was to establish a baseline rate of significant histologic changes and to determine the main characteristics of IT patients. We systematically searched PubMed, Embase, and Web of Science. Studies reporting liver biopsy results (inflammation grade or fibrosis stage) for adults with chronic hepatitis B virus (HBV) infection in the IT phase diagnosed by serological criterion were included to pool the rate of significant histologic changes. Studies that enrolled subjects with confirmed chronic HBV infection in the IT phase diagnosed by serological and liver biopsy criteria (dual criteria) were included to pool the mean values of main characteristics among IT patients. Of 319 studies screened, 15 were eventually included in the meta-analysis. The pooled rates of significant liver fibrosis and inflammatory activity for 10 studies were 10% (95% confidence interval [CI] 0.06-0.18) and 16% (95% CI 0.07-0.31), respectively. The pooled mean values of age, alanine aminotransferase level, HBV DNA level, and HBsAg level for another 5 studies with IT patients diagnosed by dual criteria were 30.7 years (95% CI 27.31-34.09), 26.64 IU/mL (95% CI 24.45-28.83), 8.41 log₁₀ cp/mL (95% CI 7.59-9.23), and 4.24 log₁₀ IU/mL (95% CI 3.67-4.82), respectively. Significant histologic changes were not rare events among IT patients. Strictly defined serological diagnostic criteria for the IT phase are warranted.

Development of a sensitive, multi-assay platform to monitor low levels of HBV DNA and pgRNA in patients with chronic hepatitis B virus infection

HBV cure rates remain low despite prolonged nucleos(t)ide (NrtI) therapy, likely due to persistent residual viral replication and an inability to eliminate covalently closed circular DNA (cccDNA). Therapies with novel mechanisms of action against hepatitis B virus (HBV) are being explored with the goal of achieving sustained off-treatment response and a functional cure without requiring lifelong therapy. Recent studies have indicated that serum HBV DNA levels (a biomarker for viral replication) combined with serum pregenomic RNA (pgRNA) levels (a surrogate for intrahepatic cccDNA transcriptional activity), may provide a better prediction for the risk of liver-related complications. Current HBV DNA assays, such as the COBAS AmpliPrep/COBAS TaqMan HBV test v2.0, quantitate HBV DNA down to 20 IU/mL, but are not able to monitor loss of residual virus in patients on NrtI therapy. There are no commercially available assays approved to detect serum/plasma HBV pgRNA levels. We have developed a multi-assay panel of highly sensitive nucleic acid assays designed to monitor levels of HBV DNA, pgRNA and total nucleic acids (TNA, composite DNA + pgRNA) in clinical specimens and to monitor changes during treatment with new antiviral combination regimens.

Hepatitis B Virus DNA Integration Drives Carcinogenesis and Provides a New Biomarker for HBV-related HCC

Hepatitis B virus (HBV) DNA integration is an incidental event in the virus replication cycle and occurs in less than 1% of infected hepatocytes during viral infection. However, HBV DNA is present in the genome of approximately 90% of HBV-related HCCs and is the most common somatic mutation. Whole genome sequencing of liver tissues from chronic hepatitis B patients showed integration occurring at random positions in human chromosomes; however, in the genomes of HBV-related HCC patients, there are integration hotspots. Both the enrichment of the HBV-integration proportion in HCC and the emergence of integration hotspots suggested a strong positive selection of HBV-integrated hepatocytes to progress to HCC. The activation of HBV integration hotspot genes, such as telomerase (TERT) or histone methyltransferase (MLL4/KMT2B), resembles insertional mutagenesis by oncogenic animal retroviruses. These candidate oncogenic genes might shed new light on HBV-related HCC biology and become targets for new cancer therapies. Finally, the HBV integrations in individual HCC contain unique sequences at the junctions, such as virus-host chimera DNA (vh-DNA) presumably being a signature molecule for individual HCC. HBV integration may thus provide a new cell-free tumor DNA biomarker to monitor residual HCC after curative therapies or to track the development of de novo HCC.

Hepatitis B virus pre-genomic RNA and hepatitis B core-related antigen reductions at week 4 predict favourable hepatitis B surface antigen response upon long-term nucleos(t)ide analogue in chronic hepatitis B

BACKGROUND/AIMS

We investigated the dynamics of serum HBV pre-genomic RNA (pgRNA) and hepatitis B core-related antigen (HBcrAg) in patients receiving nucleos(t)ide analogues (NAs) and their predictability for favourable suppression of serum hepatitis B surface antigen (HBsAg).

METHODS

Serum viral biomarkers were measured at baseline, weeks 4, 12, 24, 36, and 48 of treatment. Patients were followed up thereafter and serum HBsAg level was measured at end of follow-up (EOFU). Favourable HBsAg response (FHR) was defined as ≤100 IU/mL or HBsAg seroclearance upon EOFU.

RESULTS

Twenty-eight hepatitis B e antigen (HBeAg)-positive and 36 HBeAg-negative patients (median, 38.2 years old; 71.9% male) were recruited with median follow-up duration of 17.1 years (interquartile range, 12.8-18.2). For the entire cohort, 22/64 (34.4%) achieved FHR. For HBeAg-positive patients, serum HBV pgRNA decline at week 4 was significantly greater for patients with FHR compared to non-FHR (5.49 vs. 4.32 log copies/mL, respectively; P=0.016). The area under the receiver-operating-characteristic curve (AUROC) for week 4 HBV pgRNA reduction to predict FHR in HBeAg-positive patients was 0.825 (95% confidence interval [CI], 0.661-0.989). For HBeAg-negative patients, instead of increase in serum HBcrAg in non-FHR patients, FHR patients had median reduction in HBcrAg at week 4 (increment of 1.75 vs. reduction of 2.98 log U/mL; P=0.023). The AUROC for week 4 change of HBcrAg to predict FHR in HBeAg-negative patients was 0.789 (95% CI, 0.596-0.982).

CONCLUSION

Early on-treatment changes of serum HBV pgRNA and HBcrAg at 4 weeks predict HBsAg seroclearance or ≤100 IU/mL in NA-treated CHB patients upon long-term FU.

Safety and efficacy of bulevirtide in combination with tenofovir disoproxil fumarate in patients with hepatitis B virus and hepatitis D virus coinfection (MYR202): a multicentre, randomised, parallel-group, open-label, phase 2 trial

BACKGROUND

Bulevirtide is a first-in-class peptidic entry inhibitor for hepatitis B virus (HBV) and hepatitis D virus infection. In July, 2020, bulevirtide 2 mg received conditional marketing authorisation by the European Medical Agency for treatment of chronic hepatitis D virus infection. We investigated the antiviral activity of bulevirtide in patients chronically infected with HBV and hepatitis D virus.

METHODS

MYR202 (ClinicalTrials.gov, NCT03546621; EudraCT, 2016-000395-13) was a multicentre, parallel-group, randomised, open-label, phase 2 trial. Adults (aged 18-65 years) with chronic hepatitis D virus infection, including patients with cirrhosis and patients who had contraindications to PegIFNα treatment or for whom treatment did not work, were eligible and were enrolled from four hospitals in Germany and 12 hospitals in Russia. Patients were randomly assigned (1:1:1:1) to receive 2 mg (n=28), 5 mg (n=32), or 10 mg (n=30) subcutaneous bulevirtide once per day with tenofovir disoproxil fumarate (TDF; 245 mg once per day orally) or TDF alone (245 mg once per day orally; n=30) for 24 weeks. Randomisation was done using a digital block scheme with stratification, consisting of 480 randomisation numbers separated into 30 blocks. The primary endpoint was undetectable hepatitis D virus RNA or 2 log10 IU/mL or higher decline in hepatitis D virus RNA at week 24, which was analysed in the modified intention-to-treat population, including patients who received study medication at least once after randomisation. Hepatitis D virus RNA concentrations were monitored until week 48. Safety was assessed for all patients who received at least one dose of bulevirtide or TDF.

FINDINGS

Between Feb 16, 2016, and Dec 8, 2016, 171 patients with chronic hepatitis D virus infection were screened; 51 were ineligible based on the exclusion criteria and 120 patients (59 with cirrhosis) were enrolled. At week 24, 15 (54%, 95% CI 34-73) of 28 patients achieved undetectable hepatitis D virus RNA or a 2 log10 IU/mL or more decline in hepatitis D virus RNA (p<0·0001 vs TDF alone) with 2 mg bulevirtide, 16 (50%, 32-68) of 32 with 5 mg bulevirtide (p<0·0001), and 23 (77%, 58-90) of 30 with 10 mg bulevirtide (p<0·0001), versus one (4%, 0·1-18) of 28 with TDF alone. By week 48 (24 weeks after bulevirtide cessation), hepatitis D virus RNA concentrations had rebounded, with median changes from week 24 to week 48 of 1·923 log10 IU/mL (IQR 0·566-2·485) with 2 mg bulevirtide, 1·732 log10 (0·469-2·568) with 5 mg bulevirtide, and 2·030 log10 (1·262-2·903) with 10 mg bulevirtide. There were no deaths associated with treatment. Three (9%) patients in the bulevirtide 5 mg group, two (7%) patients in the bulevirtide 10 mg group, and one (4%) patient in the TDF group had serious adverse events. Common treatment-emergent adverse events included asymptomatic bile salt increases and increases in alanine aminotransferase and aspartate aminotransferase.

INTERPRETATION

Bulevirtide induced a significant decline in hepatitis D virus RNA over 24 weeks. After cessation of bulevirtide, hepatitis D virus RNA concentrations rebounded. Longer treatment durations and combination therapies should be investigated.

FUNDING

Hepatera LLC, MYR GmbH, and the German Centre for Infection Research, TTU Hepatitis.

How to Effectively Monitor Aging Patients with Chronic Hepatitis B: A Review

Hepatitis B virus (HBV) infection is a major global public health challenge associated with significant morbidity and mortality. Due to worldwide population aging, HBV infection in the elderly will become increasingly prevalent. Effective universal vaccination programs exist but these are largely targeted towards the younger population. Therefore, the elderly population remains at risk of higher disease burden. New diagnoses of HBV infection in the elderly are usually asymptomatic chronic infections which increases their risk of developing cirrhosis, hepatocellular carcinoma, and liver disease-related mortality, especially if left untreated. Physiological changes and the increasing prevalence of multimorbidity associated with aging also potentially worsen outcomes in elderly patients with chronic HBV infection. Therefore, this cohort of patients should be monitored closely and effectively. Current international clinical practice guidelines unfortunately do not provide hard treatment endpoints specific to elderly patients with chronic HBV infection. Management of these patients is complex and requires an individualized approach. Multiple factors such as physiological changes, comorbidities, compliance, treatment tolerability and efficacy, burden of treatment, and realistic treatment goals need to be considered. Shared decision-making between patient and clinician is essential to ensure that the final decision for or against treatment aligns with the patient's values and preferences. This review article aims to summarize the monitoring and management of chronic HBV infection in the aging population.

Activation of distinct antiviral T-cell immunity: A comparison of bi- and trispecific T-cell engager antibodies with a chimeric antigen receptor targeting HBV envelope proteins

Despite the availability of an effective prophylactic vaccine, 820,000 people die annually of hepatitis B virus (HBV)-related liver disease according to WHO. Since current antiviral therapies do not provide a curative treatment for the 296 million HBV carriers around the globe, novel strategies to cure HBV are urgently needed. A promising approach is the redirection of T cells towards HBV-infected hepatocytes employing chimeric antigen receptors or T-cell engager antibodies. We recently described the effective redirection of T cells employing a second-generation chimeric antigen receptor directed against the envelope protein of hepatitis B virus on the surface of infected cells (S-CAR) as well as bispecific antibodies that engage CD3 or CD28 on T cells employing the identical HBV envelope protein (HBVenv) binder. In this study, we added a trispecific antibody comprising all three moieties to the tool-box. Cytotoxic and non-cytolytic antiviral activities of these bi- and trispecific T-cell engager antibodies were assessed in co-cultures of human PBMC with HBV-positive hepatoma cells, and compared to that of S-CAR-grafted T cells. Activation of T cells via the S-CAR or by either a combination of the CD3- and CD28-targeting bispecific antibodies or the trispecific antibody allowed for specific elimination of HBV-positive target cells. While S-CAR-grafted effector T cells displayed faster killing kinetics, combinatory treatment with the bispecific antibodies or single treatment with the trispecific antibody was associated with a more pronounced cytokine release. Clearance of viral antigens and elimination of the HBV persistence form, the covalently closed circular (ccc) DNA, through cytolytic as well as cytokine-mediated activity was observed in all three settings with the combination of bispecific antibodies showing the strongest non-cytolytic, cytokine-mediated antiviral effect. Taken together, we demonstrate that bi- and trispecific T-cell engager antibodies can serve as a potent, off-the-shelf alternative to S-CAR-grafted T cells to cure HBV.

Perspectives on current controversial issues in the management of chronic HBV infection

Clinical and basic research in the past decades has achieved consensus in the understanding of chronic hepatitis B virus (HBV) infection and the management of chronic hepatitis B and HBV-cirrhosis. However, debatable challenges to the existing consensus in the concept and/or definitions have emerged. These include (1). alanine aminotransferase upper limit of normal: traditional laboratory-defined vs fixed; (2). nomenclature for phases of chronic HBV infection: classical vs EASL proposal; (3). indication of antiviral therapy: to treat patients vs to treat HBV; (4). finite vs indefinite long-term antiviral therapy: A. finite therapy in HBV-cirrhosis; B. retreatment decision: biochemical markers vs HBsAg/ALT kinetics. The pros and cons of these controversial issues were reviewed, assessed, and discussed in depth based on relevant lines of scientific evidence, intended to clarify or solve these controversial issues.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Mechanisms and strategies to overcome immunotherapy resistance in hepatobiliary malignancies

Unprecedented advances have been achieved in hepatobiliary cancer treatment with immune checkpoint blockade (ICB). However, the efficacy of ICB in patients with hepatobiliary malignancies is still limited. Resistance to immunotherapies is often orchestrated by complicated tumor-host-microenvironment interactions but could also occur after initial efficacy, mostly when only partial responses are obtained. Clarification of cancer-resistance mechanisms will be beneficial to provide the rationale for the administration of personalized drugs. Here, we review the factors related to resistance to immune-targeted therapies in hepatobiliary malignancies and discuss the potential strategies for overcoming resistance and future directions of immunotherapy development.

Gut microbiota of hepatitis B virus-infected patients in the immune-tolerant and immune-active phases and their implications in metabolite changes

BACKGROUND

The microbes and metabolomics of microbiota dysbiosis in the gut in the different phases of hepatitis B virus (HBV) infection are not fully understood.

AIM

To investigate the specific gut microbiota and metabolites of the immune-tolerant (IT) and immune-active (IA) phases of chronic hepatitis B (CHB).

METHODS

Clinical fecal samples from healthy individuals and patients in the IT and IA phases of HBV infection were collected. Next, non-target metabolomics, bioinformatics, and 16S rDNA sequencing analyses were performed.

RESULTS

A total of 293 different metabolites in 14 phyla, 22 classes, 29 orders, 51 families, and 190 genera were identified. The four phyla of Firmicutes, Bacteroidetes, Actinobacteria, and Proteobacteria were the most abundant, accounting for 99.72%, 99.79%, and 99.55% in the healthy controls, IT-phase patients, and IA-phase patients, respectively. We further identified 16 genera with different richness in the IT phase and IA phase of HBV infection. Of the 134 named metabolites, 57 were upregulated and 77 were downregulated. A total of 101 different metabolic functions were predicted in this study, with 6 metabolic pathways having the highest enrichments, namely carbohydrate metabolism (14.85%), amino acid metabolism (12.87%), lipid metabolism (11.88%), metabolism of cofactors and vitamins (11.88%), xenobiotic biodegradation (9.9%), and metabolism of terpenoids and polyketides (7.92%).

CONCLUSION

These findings provide observational evidence of compositional alterations of the gut microbiome and some related metabolites in patients with IT-phase or IA-phase HBV infection. Further studies should investigate whether microbiota modulation can facilitate the progression of CHB and the cause-effect relationship between the gut microbiota and CHB.