Hepatitis B Virus Pregenomic RNA Is Present in Virions in Plasma and Is Associated With a Response to Pegylated Interferon Alfa-2a and Nucleos(t)ide Analogues

Phase 1 trial of the safety, pharmacokinetics, and antiviral activity of EDP-514 in untreated viremic chronic hepatitis B patients

BACKGROUND/AIMS

Oral EDP-514 is a potent core protein inhibitor of hepatitis B virus (HBV) replication, which produced a >4-log viral load reduction in HBV-infected chimeric mice with human liver cells. This study evaluated the safety, pharmacokinetics, and antiviral activity of three doses of EDP-514 in treatment-naive viremic patients with HBeAgpositive or -negative chronic HBV infection.

METHODS

Patients with HBsAg detectable at screening and at least 6 months previously were eligible. HBeAg-positive and -negative patients had a serum/plasma HBV DNA level ≥20,000 and ≥2,000 IU/mL, respectively. Twenty-five patients were randomized to EDP-514 200 (n=6), 400 (n=6) or 800 mg (n=7) or placebo (n=6) once daily for 28 days.

RESULTS

A dose-related increase in EDP-514 exposure (AUClast and Cmax) was observed across doses. At Day 28, mean reductions in HBV DNA were -2.9, -3.3, -3.5 and -0.2 log10 IU/mL with EDP-514 200 mg, 400 mg, 800 mg, and placebo groups, respectively. The corresponding mean change from baseline for HBV RNA levels was -2.9, -2.4, -2.0, and -0.02 log10 U/mL. No virologic failures were observed. No clinically meaningful changes from baseline were observed for HBsAg, HBeAg or HBcrAg. Nine patients reported treatment emergent adverse events of mild or moderate severity with no discontinuations, serious AEs or deaths.

CONCLUSION

In treatment-naïve viremic patients, oral EDP-514 was generally safe and well-tolerated, displayed PK profile supportive of once-daily dosing, and markedly reduced HBV DNA and HBV RNA.

Predictive role of early treatment dynamics of HBV RNA and HBcrAg for HBeAg seroconversion in children with chronic hepatitis B

This study aimed to assess the predictive capacity of emerging serological markers, serum HBV RNA and HBcrAg, for HBeAg seroconversion in children with HBeAg-positive chronic hepatitis B (CHB). Treatment-naïve HBeAg-positive CHB children who admitted to the Liver Disease Center of Hunan Children's Hospital between April 2021 and September 2022 and received treatment with the combined entecavir and interferon-alpha treatment were recruited. Serum HBV RNA and HBcrAg were measured at baseline and Weeks 12, 24, and 48 of treatment. Our study showed that serum HBV RNA (HR = 0.71, 95% CI: 0.56-0.91, p = 0.006), HBcrAg (HR = 0.60, 95% CI: 0.43-0.84, p = 0.003), and HBsAg (HR = 0.49, 95%CI: 0.36-0.69, p < 0.001) at Week 12 were independent predictors of HBeAg seroconversion. ROC curve analysis presented that serum HBV RNA decline value (ΔHBV RNA) at Week 36 and HBcrAg decline value (ΔHBcrAg) at Week 12 (AUC = 0.871, p = 0.003 and AUC = 0.810, p = 0.003, respectively) could effectively predict HBeAg seroconversion. Furthermore, the optimal critical values were determined and the children with ΔHBV RNA > 3.759 log10 copies/mL at Week 36 or ΔHBcrAg >0.350 log10 U/mL at Week 12 more likely to achieve HBeAg seroconversion. The serum HBV RNA and HBcrAg provide new insights into the treatment of CHB in children. Early assessment of serum HBV RNA and HBcrAg during treatment can assist clinical decision-making and optimize individualized therapeutic approaches.

The significance of detecting HBV pgRNA and HBcrAg in HBV patients treated with NAs

The value of detecting hepatitis B virus (HBV), pregenomic RNA (pgRNA), and hepatitis B core-related antigen (HBcrAg), both separately and jointly, in the management of HBV patients undergoing treatment with Nucleotide Analog was investigated. A total of 149 HBV patients who were being treated with Nucleotide Analog were enrolled in this study. The quantitative levels of HBV pgRNA and HBcrAg in the sera of these patients were determined, aiming to comprehend their replication levels and expression during the course of antiviral therapy. The patients were separated into 3 groups based on treatment duration: treatment time ≤ 12 months, treatment time ranging from 12 months to <60 months, and treatment time ≥ 60 months. Significantly different levels of HBcrAg and HBV pgRNA were observed among 3 groups (P < .05). In the group of patients with positive hepatitis B e antigen, both HBcrAg and pgRNA levels were higher compared to the group with negative hepatitis B e antigen, and this difference between the 2 groups was found to be statistically significant. Stratified analysis based on levels of hepatitis B surface antigen (HBsAg) revealed that the group with HBsAg levels < 100 IU/mL had lower levels of both HBcrAg and pgRNA compared to the group with HBsAg levels ≥ 100 IU/mL (P < .001). Following antiviral therapy, various degrees of transcription of covalently closed circular DNA continue to exist within the liver of HBV patients. The levels of serum HBcrAg and HBV pgRNA vary among patients with different treatment durations, indicating their efficacy in evaluating disease conditions during antiviral therapy.

Selective detection of HBV pre-genomic RNA in chronic hepatitis B patients using a novel RT-PCR assay

In chronic hepatitis B (CHB) patients, quantification of HBV pgRNA in plasma has the potential to provide information on disease prognosis and liver injury or histopathology. However, current methods for detecting HBV pgRNA present technical difficulties due to the co-existence of HBV DNA in plasma samples. We have successfully established a novel one-step RT-PCR assay that allows selective quantification of HBV pgRNA. Two cohorts of participants were recruited for assay validation, including treatment-naïve patients with CHB and HBeAg-positive CHB patients who were treated with Tenofovir and monitored for 6 months to assess the predictive value of baseline HBV RNA for HBeAg seroclearance. Statistical analysis was performed using MedCalc version 20.019 software. The novel selective one-step RT-PCR assay for detecting HBV pgRNA was validated with a limit of detection of 100 copies/mL. The assay was able to selectively measure HBV pgRNA even in the presence of excess HBV rcDNA. In treatment-naïve CHB patients, HBV pgRNA levels were significantly lower than HBV DNA concentration. Serum HBV DNA levels and HBeAg status were positively associated with HBV pgRNA. Baseline serum HBV pgRNA levels were found to be strong predictors of HBeAg seroclearance after 6 months of Tenofovir treatment. The study presents a novel RT-PCR assay that allows accurate measurement of plasma HBV pgRNA in chronic hepatitis B patients, even in the presence of excess HBV DNA. The assay is highly selective and represents a significant advancement with potential for further breakthroughs in understanding the clinical significance of HBV pgRNA.

A novel hepatitis B virus capsid assembly modulator QL-007 inhibits HBV replication and infection through altering capsid assembly

The core protein allosteric modulators (CpAMs) have shown great potential as highly effective antiviral drugs against hepatitis B virus (HBV) in preclinical studies and clinical trials. In this study, we evaluated a small molecule compound called QL-007, which could potentially influence capsid assembly, using HBV replicated and susceptible cell models as well as mice infected with rAAV-HBV. QL-007 significantly inhibited HBV replication in a dose-dependent manner both in vitro and in vivo, resulting in significant decreases in HBV DNA, 3.5 kb HBV RNA and HBeAg. Furthermore, QL-007 not only induced the formation of misshaped Cp149 capsids but also possessed the capability to disassemble HBV capsids. It is noteworthy that QL-007 effectively reduced cccDNA biosynthesis in de novo infections. Mechanistically, QL-007 blocked the encapsidation of pgRNA and induced aberrant polymers assembly at concentrations ≥100 nM, while having no impact on the stability of core proteins. In conclusion, our findings underscore the potential of QL-007 as an effective agent against HBV replication and introduce it as a novel CpAM for the antiviral treatment of chronic hepatitis B.

Cellular Factors Involved in the Hepatitis D Virus Life Cycle

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

Measuring hepatitis B pgRNA stability using an updated automated HBV pgRNA assay with increased sensitivity

BACKGROUND

HBV pregenomic RNA (pgRNA) is a circulating biomarker for covalently closed circular DNA activity in HBV-infected individuals and has been studied for treatment efficacy, disease staging, and off-therapy outcomes; however, data on the stability are scarce. Increasing HBV pgRNA assay sensitivity may improve its predictive value and provide additional insights at low viral levels.

METHODS

Modifications to a fully automated first (v1) generation HBV pgRNA assay improved sensitivity up to 15-fold over the previous assay. Flexible sample input volumes yielded lower limits of quantitation of 10 and 22 copies/mL for 0.6 and 0.2 mL assays, respectively. Results are standardized to secondary standards that are traceable to the WHO HBV DNA standard, and internal and external controls are included.

RESULTS

Comparison between v1 and modified v2 assays showed increased sensitivity from 152 copies/mL with v1 to 10 (0.6 mL) and 22 (0.2 mL) copies/mL with v2, respectively. Quantitated v2 results were indistinguishable from v1, indicating that comparisons can be made to previous studies. Single timepoint treatment-naive blood donors or longitudinal draws from patients with chronic hepatitis B on AB-729, an investigational siRNA therapy, showed improved detection and quantifiable pgRNA with v2 compared with v1. Stability testing demonstrated excellent HBV pgRNA plasma stability after 3 freeze-thaw cycles, for at least 7 days at 25-37 °C and at least 30 days at 4°C, with ≤0.25 Log U/mL decrease.

CONCLUSION

HBV pgRNA v2 assays with increased sensitivity and flexible input volumes demonstrated increased detection and quantitation of low viral titer samples. Highly sensitive HBV pgRNA assays may be useful in refining predictive treatment outcomes based on this marker. HBV pgRNA was stable under multiple conditions, which increases the reliability of this marker.

Sera of Individuals Chronically Infected with Hepatitis B Virus (HBV) Contain Diverse RNA Types Produced by HBV Replication or Derived from Integrated HBV DNA

This study aimed to better characterize the repertoire of serum hepatitis B virus (HBV) RNAs during chronic HBV infection in humans, which remains understudied. Using reverse transcription-PCR (RT-PCR), real-time quantitative PCR (RT-qPCR), RNA-sequencing, and immunoprecipitation, we found that (i) >50% of serum samples bore different amounts of HBV replication-derived RNAs (rd-RNAs); (ii) a few samples contained RNAs transcribed from integrated HBV DNA, including 5'-HBV-human-3' RNAs (integrant-derived RNAs [id-RNAs]) and 5'-human-HBV-3' transcripts, as a minority of serum HBV RNAs; (iii) spliced HBV RNAs were abundant in <50% of analyzed samples; (iv) most serum rd-RNAs were polyadenylated via conventional HBV polyadenylation signal; (v) pregenomic RNA (pgRNA) was the major component of the pool of serum RNAs; (vi) the area of HBV positions 1531 to 1739 had very high RNA read coverage and thus should be used as a target for detecting serum HBV RNAs; (vii) the vast majority of rd-RNAs and pgRNA were associated with HBV virions but not with unenveloped capsids, exosomes, classic microvesicles, or apoptotic vesicles and bodies; (viii) considerable rd-RNAs presence in the circulating immune complexes was found in a few samples; and (ix) serum relaxed circular DNA (rcDNA) and rd-RNAs should be quantified simultaneously to evaluate HBV replication status and efficacy of anti-HBV therapy with nucleos(t)ide analogs. In summary, sera contain various HBV RNA types of different origin, which are likely secreted via different mechanisms. In addition, since we previously showed that id-RNAs were abundant or predominant HBV RNAs in many of liver and hepatocellular carcinoma tissues as compared to rd-RNAs, there is likely a mechanism favoring the egress of replication-derived RNAs. IMPORTANCE The presence of integrant-derived RNAs (id-RNAs) and 5'-human-HBV-3' transcripts derived from integrated hepatitis B virus (HBV) DNA in sera was demonstrated for the first time. Thus, sera of individuals chronically infected with HBV contained both replication-derived and integrant-transcribed HBV RNAs. The majority of serum HBV RNAs were the transcripts produced by HBV genome replication, which were associated with HBV virions and not with other types of extracellular vesicles. These and other above-mentioned findings advanced our understanding of the HBV life cycle. In addition, the study suggested a promising target area on the HBV genome to increase sensitivity of the detection of serum HBV RNAs and supported the idea that simultaneous detection of replication-derived RNAs (rd-RNAs) and relaxed circular DNA (rcDNA) in serum provides more adequate evaluation of (i) the HBV genome replication status and (ii) the durability and efficiency of the therapy with anti-HBV nucleos(t)ide analogs, which could be useful for improvement of the diagnostics and treatment of HBV-infected individuals.

Dihydromyricetin inhibits Hepatitis B virus replication by activating NF-κB, MAPKs, and autophagy in HepG2.2.15 cells

BACKGROUND

Hepatitis B virus (HBV) infection is a severe global health problem, and there has been no effective method to eliminate HBV. This study was designed to explore the pharmacological mechanism of Dihydromyricetin (DHM) treatment on HBV replication in vitro.

METHODS AND RESULTS

DHM is a flavonoid compound from Ampelopsis grossedentata. Using HepG2.2.15 cells, which can stably express HBV in vitro, we demonstrated that DHM treatment dramatically reduced HBV replication and secretions of HBsAg and HBeAg. Meanwhile, DHM inhibited mRNA expression of HBV RNAs in HepG2.2.15 cells, including Total HBV RNA, HBV pregenomic RNA (pgRNA), and HBV precore mRNA (pcRNA). Also, DHM elevated the mRNA expressions of inflammatory cytokines and antiviral effectors. In contrast, DHM decreased the mRNA level of HNF4α, which positively correlated with HBV replication. Further studies show that the activation of nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathway played a critical role in DHM-initiated inhibition of HBV replication in HepG2.2.15 cells. Besides, activated autophagy was another contributor that may accelerate the clearance of HBV components.

CONCLUSION

In summary, DHM could suppress HBV replication by activating NF-κB, MAPKs, and autophagy in HepG2.2.15 cells. Our studies shed light on the future application of DHM for the clinical treatment of HBV infection.

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.

A standardized assay for the quantitative detection of serum HBV RNA in chronic hepatitis B patients

Serum hepatitis B virus (HBV) pregenomic RNA (pgRNA) is a surrogate marker for reflecting the transcriptional activity of covalently closed circular DNA. However, there is still no standardized assay for the quantitative detection of serum HBV RNA in chronic hepatitis B patients. In this study, quantitative polymerase chain reactions for detecting the preC/C-RNA (preC/C region HBV pgRNA), SF-RNA (splicing variants-free pgRNA) and XR-RNA (X region remained pgRNA) regions were set up. The dynamic changes of serum pgRNA splicing variants and 3′ terminal truncations were analysed in three retrospective cohorts: 35 treatment-naive chronic HBV-infected patients (cohort A), 52 chronic hepatitis B (CHB) patients who received nucleos(t)ide analogs (NAs) therapy for 48 weeks (cohort B) and eight CHB patients who are under long-term NAs treatment (cohort C). The accuracy and sensitivity of HBV RNA detection were assessed by the National Standard of HBV RNA. We confirmed that high proportions of pgRNA splicing variants and 3′ terminal truncations were present and significantly affect the quantitative detection of serum HBV RNA in both treatment-naive and NAs-treated CHB patients. To achieve the higher accuracy and sensitivity on the detection of HBV RNA level, the primers and probes should be designed at the 5′ terminal region of HBV genome and outside the mainly spliced sequence of pgRNA, especially for CHB patients under long-term NAs treatment. This study would help to better understand the significance of the pgRNA splicing variants and 3′ terminal truncations, and further guide the clinical detection of serum HBV RNA.

EDP-514 in healthy subjects and nucleos(t)ide reverse transcriptase inhibitor-suppressed patients with chronic hepatitis B

Background

Chronic hepatitis B (CHB) remains a major cause of morbidity and mortality. EDP-514 is a potent core inhibitor of hepatitis B virus (HBV) that reduces viral load reduction in HBV-infected chimeric mice. This first-in-human study evaluated the safety, tolerability, and pharmacokinetics (PK) of EDP-514 in healthy subjects and antiviral activity in patients with CHB.

Methods

In Part 1, 82 subjects received placebo or EDP-514 in fed or fasted state as single ascending doses of 50–800 mg and multiple ascending doses of 200–800 mg for 14 days. In Part 2, 24 HBV DNA-suppressed, nucleos(t)ide (NUC)-treated (i.e., NUC-suppressed) CHB patients received EDP-514 200–800 mg or placebo for 28 days.

Results

EDP-514 was well tolerated in healthy subjects and CHB patients with most adverse events of mild intensity. In Part 1, EDP-514 exposure increased in an approximately dose proportional manner up to 600 mg after single doses and up to 400 mg after 14-day dosing. In Part 2, EDP-514 exposure increased linearly with dose on Day 1 and Day 28, with some accumulation for Day 28 and median trough concentrations (Ctrough) approximately 20-fold above the protein-adjusted 50% effective concentration (EC50) for the dose range. Mean change in HBV RNA from baseline to Day 28 was −2.03, −1.67, −1.87, and −0.58 log U/mL in the 200 mg, 400 mg, 800 mg, and placebo CHB groups, respectively.

Conclusions

EDP-514 was well tolerated, had a PK profile supporting once daily dosing, and reduced HBV RNA levels in NUC-suppressed CHB patients.

A roadmap for serum biomarkers for hepatitis B virus: current status and future outlook

Globally, 296 million people are infected with hepatitis B virus (HBV), and approximately one million people die annually from HBV-related causes, including liver cancer. Although there is a preventative vaccine and antiviral therapies suppressing HBV replication, there is no cure. Intensive efforts are under way to develop curative HBV therapies. Currently, only a few biomarkers are available for monitoring or predicting HBV disease progression and treatment response. As new therapies become available, new biomarkers to monitor viral and host responses are urgently needed. In October 2020, the International Coalition to Eliminate Hepatitis B Virus (ICE-HBV) held a virtual and interactive workshop on HBV biomarkers endorsed by the International HBV Meeting. Various stakeholders from academia, clinical practice and the pharmaceutical industry, with complementary expertise, presented and participated in panel discussions. The clinical utility of both classic and emerging viral and immunological serum biomarkers with respect to the course of infection, disease progression, and response to current and emerging treatments was appraised. The latest advances were discussed, and knowledge gaps in understanding and interpretation of HBV biomarkers were identified. This Roadmap summarizes the strengths, weaknesses, opportunities and challenges of HBV biomarkers.

Circulating HBV RNA: From biology to clinical applications

Chronic HBV infection can hardly be cured due to the persistence of an intrahepatic pool of viral covalently closed circular DNA (cccDNA) transcription template, which is refractory to current antivirals. The direct analyses of cccDNA quantity and transcriptional activity require an invasive biopsy. Recently, circulating HBV RNA has been identified as a promising noninvasive surrogate marker of cccDNA and can be used for monitoring disease progression and predicting prognosis of patients with chronic HBV infection. To better understand this surrogate biomarker of cccDNA, we reviewed the current knowledge about the molecular characteristics and potential clinical applications of circulating HBV RNA. Specifically, we summarized the reported species and existing forms of circulating HBV RNA and discussed their biogenesis and the capacity of de novo infection by RNA virions. Moreover, we described the potential applications of circulating HBV RNA in different clinical scenarios, such as classifying the phases of chronic HBV infection, analyzing sustained on-treatment and off-treatment outcomes of treated patients, as well as predicting HCC development. Perspectives on future research of circulating HBV RNA were also proposed in this review.

Establishment and Characterization of an HBV Viral Spread and Infectious System following Long-Term Passage of an HBV Clinical Isolate in the Primary Human Hepatocyte and Fibroblast Coculture System

The existing cell culture-based methods to study hepatitis B virus (HBV) have limitations and do not allow for viral long-term passage. The aim of this study was to develop a robust in vitro long-term viral passage system with optimized cell culture conditions and a viral isolate with the ability to spread and passage. An HBV genotype A clinical isolate was subjected to multiple rounds of UV treatment and passaged in an optimized primary human hepatocyte (PHH)/human fibroblast coculture system. The passaged UV-treated virus was sequenced and further characterized. In addition, a panel of mutant viruses containing different combinations of mutations observed in this virus was investigated. The clinical isolate was passaged for 20 rounds with 21 days per round in an optimized PHH/human fibroblast coculture system while subject to UV mutagenesis. This passaged UV-mutated isolate harbored four mutations: G225A (sR24K) in the S gene, A2062T in the core gene, and two mutations G1764A and C1766T (xV131I) in the basal core promoter (BCP) region. In vitro characterization of the four mutations suggested that the two BCP mutations G1764A and C1766T contributed to the increased viral replication and viral infectivity. A robust in vitro long-term HBV viral passage system has been established by passaging a UV-treated clinical isolate in an optimized PHH/fibroblast coculture system. The two BCP mutations played a key role in the virus's ability to passage. This passage system can be used for studying the entire life cycle of HBV and has the potential for in vitro drug-resistance selection upon further optimization. IMPORTANCE The existing cell culture-based methods to study HBV have limitations and do not allow for viral long-term passage. In this study, an HBV genotype A clinical isolate was subjected to multiple rounds of UV treatment and passaged in an optimized PHH/human fibroblast coculture system. This passaged UV-mutated isolate carried four mutations across the HBV genome, and in vitro characterization of the four mutations suggested that the two basal core promoter (BCP) mutations G1764A and C1766T played a key role in the virus's ability to passage. In summary, we have developed a robust in vitro long-term HBV viral passage system by passaging an UV-treated HBV genotype A clinical isolate in an optimized PHH/human fibroblast coculture system. This passage system can be used for studying the entire life cycle of HBV and has the potential for in vitro drug-resistance selection upon further optimization.

Review article: novel biomarkers in hepatitis B infection

BACKGROUND

Chronic hepatitis B remains a global health problem with an estimated 296 million people affected worldwide. Individuals are at risk of serious complications such as cirrhosis and hepatocellular carcinoma and accurately predicting these clinical endpoints has proven difficult. However, several viral biomarkers have recently been developed, including quantitative HBV surface antigen (qHBsAg), hepatitis B RNA (HBV RNA) and core-related antigen (HBcrAg), and shown promise in a range of clinical settings.

AIMS

To critically appraise these novel biomarkers, exploring their potential uses, availability of assays and areas for future development.

METHODS

We performed a literature search of PubMed, identifying articles published in the field of hepatitis B biomarkers between 2010 and 2022.

RESULTS

Novel biomarkers such as HBcrAg, HBV RNA and qHBsAg may be useful in predicting treatment outcomes, stratifying the risk of future complications and estimating off-treatment viral reactivation. Furthermore, HBV RNA and HBcrAg titres may accurately reflect cccDNA transcriptional activity, and this is particularly informative in the context of nucleoside analogue therapy. On a cautionary note, most studies have been performed in Caucasian or Asian populations, and methods for detecting HBV RNA lack standardisation.

CONCLUSION

Novel viral biomarkers have the potential to provide additional insights into the natural history of infection and allow a more bespoke, cost-effective framework of care. However, access remains limited, and further efforts are needed to validate their use in ethnically diverse populations, confirm predictive cut-off values, and establish their role in the era of novel antiviral therapies.

Diversity of the nucleic acid forms of circulating HBV in chronically infected patients and its impact on viral cycle

BACKGROUND

Besides the prototypical hepatitis B virus (HBV) infectious particle, which contains a full-length double-stranded DNA (flDNA), additional circulating virus-like particles, which carry pregenomic RNA (pgRNA), spliced1RNA (sp1RNA) or spliced-derived DNA (defDNA) forms have been described. We aimed to determine the level of these four circulating forms in patients and to evaluate their impact on viral lifecycle.

METHODS

Chronic HBV untreated patients (n = 162), included in the HEPATHER cohort, were investigated. Pangenomic qPCRs were set up to quantify the four circulating forms of HBV nucleic acids (HBV_naf). In vitro infection assays were performed to address the impact of HBV_naf.

RESULTS

Hierarchical clustering individualized two clusters of HBV_naf diversity among patients: (1) cluster 1 (C1) showing a predominance of flDNA; (2) cluster 2 (C2) showing various proportions of the different forms. HBeAg-positive chronic hepatitis phase and higher viral load (7.0 ± 6.4 vs 6.6 ± 6.2 Log₁₀ copies/ml; p < 0.001) characterized C2 compared to C1 patients. Among the different HBV_naf, pgRNA was more prevalent in C1 patients with high vs low HBV viral load (22.1% ± 2.5% vs 4.1% ± 1.8% of HBV_naf, p < 0.0001) but remained highly prevalent in C2 patients, whatever the level of replication. C2 patients samples used in infection assays showed that: (1) HBV_naf secretion was independent of the viral strain; (2) the viral cycle efficiency differed according to the proportion of HBV_naf in the inoculum, independently of cccDNA formation. Inoculum enrichment before infection suggests that pgRNA-containing particles drive this impact on viral replication.

CONCLUSION

Besides the critical role of HBV replication in circulating HBV_naf diversity, our data highlight an impact of this diversity on the dynamics of viral cycle.

CLINICAL TRIAL REGISTRATION

Patients were included from a prospective multicenter French national cohort (ANRS CO22 HEPATHER, NCT01953458).

Surrogate Markers for Hepatitis B Virus Covalently Closed Circular DNA

Chronic infection with the hepatitis B virus (HBV) is one of the most common causes of liver disease worldwide. Chronic HBV infection is currently incurable because of the persistence of the viral template for the viral transcripts, covalently closed circular deoxyribonucleic acid (cccDNA). Detecting changes in cccDNA transcriptional activity is key to understanding fundamental virology, determining the efficacy of new therapies, and deciding the optimal clinical management of HBV patients. In this review, we summarize surrogate circulating biomarkers that have been used to infer cccDNA levels and activity in people with chronic hepatitis B. Moreover, we outline the current shortcomings of the current biomarkers and highlight the clinical importance in improving them and expanding their use.

Quantified integrated hepatitis B virus is related to viral activity in patients with chronic hepatitis B

BACKGROUND AND AIMS

HBV can integrate in the host genome of the hepatocyte and recent findings suggest that integrated HBV contributes to the persistent production of viral proteins. Here, we quantified the levels of integrated HBV in patients with chronic hepatitis B (CHB) and analyzed the relation between HBV integration, virological activity (plasma HBV DNA and HBsAg levels), and clinical outcomes.

APPROACH AND RESULTS

We developed and validated a multistep Arthrobacter luteus (Alu)-PCR that specifically amplifies integrated HBV and RT-Alu-PCR detecting mRNA transcripts derived from integrated HBV. Pretreatment liver biopsy samples and baseline characteristics of 124 patients with CHB either treated for 48 weeks with pegylated interferon plus adefovir or tenofovir or receiving no treatment were available for analysis. Integrated HBV sequences containing open reading frame S and X (but not C) and S and X mRNA transcripts derived from integrated HBV could be detected and quantified in liver biopsies. Integrated HBV levels correlated with HBV DNA, HBsAg, alanine aminotransferase plasma levels, and the liver histology activity index but not to levels of intrahepatic covalently closed circular DNA (cccDNA), plasma pregenomic RNA, or hepatitis B core-related antigen. Multivariable logistic regression analysis showed that lower baseline HBV integration levels were independently associated with HBsAg loss (functional cure) within 5 years follow-up.

CONCLUSIONS

Integrated HBV levels are strongly correlated with surrogate markers for virological activity but not to cccDNA levels and are predictive for HBsAg loss. Our data suggest that integrated HBV is closely related to HBV replication and may therefore be an important tool in the evaluation and development of treatment modalities aiming to cure CHB.

HBcrAg Levels Are Associated With Virological Response to Treatment With Interferon in Patients With Hepatitis Delta

Standard treatment of hepatitis delta virus (HDV) infection remains pegylated-interferon alfa (peg-IFNα) in most centers, which is not only associated with rather low efficacy but several adverse events. Hepatitis B core-related antigen (HBcrAg) is linked to intrahepatic covalently closed circular DNA levels and has previously been suggested as response predictor in IFN-based treatment of hepatitis B virus (HBV) mono-infection. This study aimed to investigate the value of HBcrAg in the management of patients with HBV/HDV co-infection undergoing peg-IFNα treatment. The Hep-Net-International-Delta-Hepatitis-Intervention Trial-2 study included 120 patients co-infected with HBV/HDV. Patients were treated for 96 weeks with peg-IFNα and either tenofovir or placebo. Ninety-nine patients with HDV-RNA results 24 weeks after end of treatment (FU24) were included in this analysis, of whom 32 patients (32.3%) had undetectable HDV RNA at FU24. HBcrAg was measured at baseline, week 12, 24, 48, 96, and FU24. HBcrAg levels showed no significant correlation with HDV RNA but were significantly linked to treatment outcome. HBcrAg levels < 4.5 log IU/mL at baseline, week 24, and week 48 had high negative predictive value (NPV) for achieving undetectable HDV RNA at FU24 (81.8%, 87.1% and 95.0%, respectively). Similarly, HBcrAg levels at week 96 were significantly higher in patients with viral relapse until FU24 (3.0 vs. 3.63 log IU/mL; P = 0.0089). Baseline, week 24, and week 48 HBcrAg levels were also associated with the likelihood of achieving HBsAg level < 100 IU/mL at FU24 (HBcrAg < 3.0 log IU/mL: NPV 91.7%, 90.4% and 92.3%, respectively). Test statistics improved when combining HBcrAg with additional viral and clinical parameters. Conclusion: HBcrAg is linked to treatment response to peg-IFNα in patients with HBV/HDV co-infection and could be a promising marker to determine treatment futility.

Capsid Assembly Modulators as Antiviral Agents against HBV: Molecular Mechanisms and Clinical Perspectives

Despite a preventive vaccine being available, more than 250 million people suffer from chronic hepatitis B virus (HBV) infection, a major cause of liver disease and HCC. HBV infects human hepatocytes where it establishes its genome, the cccDNA with chromosomal features. Therapies controlling HBV replication exist; however, they are not sufficient to eradicate HBV cccDNA, the main cause for HBV persistence in patients. Core protein is the building block of HBV nucleocapsid. This viral protein modulates almost every step of the HBV life cycle; hence, it represents an attractive target for the development of new antiviral therapies. Capsid assembly modulators (CAM) bind to core dimers and perturb the proper nucleocapsid assembly. The potent antiviral activity of CAM has been demonstrated in cell-based and in vivo models. Moreover, several CAMs have entered clinical development. The aim of this review is to summarize the mechanism of action (MoA) and the advancements in the clinical development of CAMs and in the characterization of their mod of action.

Dynamics of Serum Pregenome RNA in Chronic Hepatitis B Patients Receiving 96-Month Nucleos(t)ide Analog Therapy

Background

Tissue covalently closed circular DNA (cccDNA) can reflect the activity of HBV replication. However, it is impractical to assess intrahepatic cccDNA in every outpatient. Serum pregenome RNA (pgRNA) is transcribed from intrahepatic cccDNA and may reflect the activity of intrahepatic cccDNA. We explored the dynamics and the potential role of serum pgRNA in patients receiving long-term NAs treatment.

Methods

Serum pgRNA, HBV DNA, HBsAg, HBeAg, and ALT levels were quantified, and the relationships between serum pgRNA and these common clinical indicators before and after the treatment were investigated.

Results

Serum pgRNA showed dynamic change during the 96-month NAs therapy, and serum pgRNA levels were positive and detectable in 19 patients with undetectable serum HBV DNA. Serum pgRNA showed strong and positive correlation with serum HBV DNA (r = 0.693, p < 0.001) and serum HBsAg levels (r = 0.621, p < 0.001) at baseline. Patients with HBeAg seroconversion had lower baseline serum pgRNA levels (p = 0.002). The area under the curve (AUC) of baseline serum pgRNA for predicting HBeAg seroconversion was 0.742 (95% CI: 0.606–0.850) with 63.16% sensitivity and 80.56% specificity. The cumulative HBeAg seroconversion rate was higher in patients with low serum pgRNA (p = 0.001).

Conclusion

Serum pgRNA of low level at baseline or great decline at month 6 may independently predict the high incidence of undetectable serum pgRNA at year 4 following NAs therapy, and the baseline serum pgRNA may serve as a novel predictor for HBeAg seroconversion during NAs therapy.

Serum hepatitis B virus RNA detectability, composition and clinical significance in patients with ab initio hepatitis B e antigen negative chronic hepatitis B

Background

Serum hepatitis B virus (HBV) RNA is a surrogate biomarker for intrahepatic covalently closed circular DNA (cccDNA) transcriptional activity and persistence. In this retrospective study, we investigated its presence, levels and composition in ab initio Hepatitis B e antigen (HBeAg) negative chronically infected patients and examined possible associations with disease activity and the outcome of nucleos(t)ide analogue (NA) discontinuation.

Methods

We developed a sensitive real time polymerase chain reaction (RT-PCR) for the specific detection of HBV pregenomic RNA (pgRNA) and precore (preC) mRNA and analyzed 220 serum specimens, 160 under NA treatment, from 116 Greek patients initially negative for HBeAg.

Results

HBV pgRNA was detected in 31% and preC mRNA in 15% of samples, at lower levels representing a small fraction (3.4%) of total core promoter produced transcripts. In the absence of NAs, pgRNA was detected in 57% of samples with median value of 5.19 (2.61–8.35) log₁₀ cp/mL, at lower levels than HBV DNA and correlated significantly with ALT (r = 0.764) and serum HBV DNA (r = 0.906). A wide range of HBV DNA/pgRNA ratio was observed with significant inter- and intra-patient variation. During NA treatment, pgRNA displayed low detectability (22%) and variable levels, median 3.97 (2.30– 8.13) log₁₀ cp/mL, as well as, a significant inverse correlation with the duration of treatment (r = − 0.346, p < 0.01). In 74 events of NA discontinuation, end-of-treatment pgRNA-positive compared to pgRNA-negative cases, experienced more frequently virological (p = 0.016) and clinical (p = 0.011) relapse.

Conclusions

In genotype D ab initio HBeAg negative patients, serum HBV RNA is primarily composed of pgRNA plus a minor fraction of preC mRNA transcripts. Serum pgRNA is associated with disease activity, suggesting lysis of infected hepatocytes as a possible source of serum HBV RNA in untreated patients and in the early phase of NA treatment. During long term NA treatment, detectable serum pgRNA predicts viral rebound and clinical relapse following treatment discontinuation and may thus serve as a marker for the decision of cessation of therapy.

Alternative splicing of viral transcripts: the dark side of HBV

Regulation of alternative splicing is one of the most efficient mechanisms to enlarge the proteomic diversity in eukaryotic organisms. Many viruses hijack the splicing machinery following infection to accomplish their replication cycle. Regarding the HBV, numerous reports have described alternative splicing events of the long viral transcript (pregenomic RNA), which also acts as a template for viral genome replication. Alternative splicing of HBV pregenomic RNAs allows the synthesis of at least 20 spliced variants. In addition, almost all these spliced forms give rise to defective particles, detected in the blood of infected patients. HBV-spliced RNAs have long been unconsidered, probably due to their uneasy detection in comparison to unspliced forms as well as for their dispensable role during viral replication. However, recent data highlighted the relevance of these HBV-spliced variants through (1) the trans-regulation of the alternative splicing of viral transcripts along the course of liver disease; (2) the ability to generate defective particle formation, putative biomarker of the liver disease progression; (3) modulation of viral replication; and (4) their intrinsic propensity to encode for novel viral proteins involved in liver pathogenesis and immune response. Altogether, tricky regulation of HBV alternative splicing may contribute to modulate multiple viral and cellular processes all along the course of HBV-related liver disease.

Hepatitis B core related antigen in relation to intrahepatic and circulating viral markers, before and after combination therapy

INTRODUCTION AND OBJECTIVES

Covalently closed circular (ccc)DNA acts as a viral reservoir in the liver of patients with a chronic hepatitis B (CHB) infection and can only be quantified in liver biopsies. Hepatitis B core-related antigen (HBcrAg) levels in plasma/serum have been proposed to reflect intrahepatic cccDNA-levels and may therefore monitor treatment efficacy. This study aimed to validate the relationship between HBcrAg and other intrahepatic and circulating viral markers in CHB patients with high viral load, before and after combination treatment.

MATERIALS AND METHODS

Plasma/serum levels of HBcrAg, HBsAg, HBV-DNA, and HBV pregenomic RNA (HBV-pgRNA), and intrahepatic cccDNA and HBV-DNA levels and fibrosis scores were measured in 89 CHB patients with HBV-DNA levels of >100,000 copies/mL (17,182 IU/mL). Measurements were done before and after a 48-week treatment with pegylated interferon alfa-2a and adefovir in a prospective study (ISRCTN77073364).

RESULTS

Baseline HBcrAg-values correlated strongly with intrahepatic cccDNA (ρ 0.77, p < 0.001), intrahepatic HBV-DNA (ρ 0.73, p < 0.001) and plasma/serum HBV-DNA (ρ 0.80, p < 0.001), HBV-pgRNA (ρ 0.80, p < 0.001), and to lesser extend HBsAg (ρ 0.56, p < 0.001). Baseline HBcrAg-levels could not predict functional cure (FC) but HBcrAg-levels declined more strongly in patients who developed FC or HBeAg-loss. Furthermore, most correlations persisted at the end of treatment and follow-up.

CONCLUSIONS

HBcrAg reflects cccDNA transcription activity more accurately than HBsAg and may replace HBV-DNA as a marker during future treatment regimens, especially when cccDNA transcription is targeted or nucleot(s)ide analogues are included in the treatment regime.

Cross-sectional evaluation of circulating hepatitis B virus RNA and DNA: Different quasispecies?

BACKGROUND

Different forms of pregenomic and other hepatitis B virus (HBV) RNA have been detected in patients’ sera. These circulating HBV-RNAs may be useful for monitoring covalently closed circular DNA activity, and predicting hepatitis B e-antigen seroconversion or viral rebound after nucleos(t)ide analog cessation. Data on serum HBV-RNA quasispecies, however, is scarce. It is therefore important to develop methodologies to thoroughly analyze this quasispecies, ensuring the elimination of any residual HBV-DNA. Studying circulating HBV-RNA quasispecies may facilitate achieving functional cure of HBV infection.

AIM

To establish a next-generation sequencing (NGS) methodology for analyzing serum HBV-RNA and comparing it with DNA quasispecies.

METHODS

Thirteen untreated chronic hepatitis B patients, showing different HBV-genotypes and degrees of severity of liver disease were enrolled in the study and a serum sample with HBV-DNA > 5 Log₁₀ IU/mL and HBV-RNA > 4 Log₁₀ copies/mL was taken from each patient. HBV-RNA was treated with DNAse I to remove any residual DNA, and the region between nucleotides (nt) 1255-1611 was amplified using a 3-nested polymerase chain reaction protocol, and analyzed with NGS. Variability/conservation and complexity was compared between HBV-DNA and RNA quasispecies.

RESULTS

No HBV-DNA contamination was detected in cDNA samples from HBV-RNA quasispecies. HBV quasispecies complexity showed heterogeneous behavior among patients. The Rare Haplotype Load at 1% was greater in DNA than in RNA quasispecies, with no statistically significant differences (P = 0.1641). Regarding conservation, information content was equal in RNA and DNA quasispecies in most nt positions [218/357 (61.06%)]. In 102 of the remaining 139 (73.38%), HBV-RNA showed slightly higher variability. Sliding window analysis identified 4 hyper-conserved sequence fragments in each quasispecies, 3 of them coincided between the 2 quasispecies: nts 1258-1286, 1545-1573 and 1575-1604. The 2 hyper-variable sequence fragments also coincided: nts 1311-1344 and 1461-1485. Sequences between nts 1519-1543 and 1559-1587 were only hyper-conserved in HBV-DNA and RNA, respectively.

CONCLUSION

Our methodology allowed analyzing HBV-RNA quasispecies complexity and conservation without interference from HBV-DNA. Thanks to this, we have been able to compare both quasispecies in the present study.

Controversies in Treating Chronic Hepatitis B virus: The Role of Hepatitis B Virus DNA and Surface Antigen Titer

Controversial areas in chronic hepatitis B (CHB) are those where there is uncertainty, or differences of opinion in management, or where evidence may be insufficient. Areas of controversy include whether patients with high viral load but normal liver function tests should be treated to prevent hepatocellular carcinoma (HCC) or liver disease progression to cirrhosis. Another area is whether quantitative hepatitis B surface antigen (qHBsAg) can be used to better characterize phases of CHB and prognosticate. Finally, the utility of qHBsAg in the management of patients on antiviral therapy such as interferon and nucleoside analogues could improve management practices.

Analysis of serum hepatitis B virus RNA levels among HBsAg and HBsAb copositive patients and its correlation with HBV DNA

ABSTRACT

There are approximately 2 billion HBV-infected individuals worldwide, and approximately 1.87% to 7% of these individuals are copositive for HBsAg and HBsAb.Our study detected hepatitis B virus pgRNA (HBV RNA) levels in HBsAg and HBsAb copositive patients and then analyzed the correlation with HBV DNA, HBsAg, ALT, and AST levels. A total of 149 HBsAg and HBsAb copositive patients were identified from 66,617 outpatients.HBV RNA, HBV DNA, HBsAg, ALT, and AST serum levels were significantly different in different natural phases of HBV infection (immune tolerance phase, immune clearance phase, low replication phase, and reactivation phase) with statistical significance (P < .01). HBV RNA levels were positively correlated with HBV DNA, HBsAg, ALT, and AST levels. HBV RNA and HBV DNA levels were significantly increased in the HBeAg-positive group (66 patients) compared with the HBeAg-negative group (83 patients) (P < .01). In the HBeAg-positive group, HBV RNA levels were positively correlated with HBV DNA and HBsAg levels. In the HBeAg-negative group, HBV RNA levels were positively correlated with HBV DNA. Serum HBV RNA levels were positively correlated with HBV DNA, HBsAg, ALT, and AST levels.HBV RNA could be used as a virological indicator for antiviral therapy in HBsAg and HBsAb copositive hepatitis B patients.

On-treatment HBV RNA dynamic predicts entecavir-induced HBeAg seroconversion in children with chronic hepatitis B

BACKGROUND

Hepatitis B e antigen (HBeAg) seroconversion is an important intermediate outcome in HBeAg-positive chronic hepatitis B patients. This study aimed to explore whether hepatitis B virus (HBV) RNA serum levels can predict HBeAg seroconversion treated with entecavir.

METHODS

Serum samples from HBeAg-positive children previously treated with entecavir were retrospectively analyzed. HBV RNA levels were measured at baseline, weeks 12, 24, 48, 72 of therapy. Ability of individual biomarkers to predict HBeAg seroconversion was evaluated using receiver operating characteristics (ROC) analyzes.

RESULTS

Serum HBV RNA was detectable in 51 children with a median of 6.05 (4.04-8.29) log₁₀ IU/mL at baseline. Patients with subsequent HBeAg seroconversion showed a significantly larger decline in median HBV RNA levels during treatment from baseline to week 12 of 1.96 (0.30-3.38) and to week 24 of 2.27 (1.20-3.38) log₁₀ IU/mL, respectively, in comparison to HBeAg-positive patients without HBeAg seroconversion (P < 0.001). Levels of HBV RNA at treatment weeks 12 and 24 showed good ability to predict HBeAg seroconversion (area under ROC scores > 0.85, P < 0.001).

CONCLUSION

On-treatment HBV RNA dynamic predicts entecavir-induced HBeAg seroconversion in children with chronic hepatitis B living in China.

Serum hepatitis B virus RNA level is associated with biochemical relapse in patients with chronic hepatitis B infection who discontinue nucleos(t)ide analogue treatment

BACKGROUND

Nucleos(t)ide analogue (NA) discontinuation may be attempted in carefully selected patients with chronic hepatitis B (CHB) infection.

AIM

To investigate whether a novel serum marker of quantitative hepatitis B virus (HBV) RNA levels could predict biochemical relapse after NA discontinuation.

METHODS

We prospepctively followed non-cirrhotic Asian patients with CHB who stopped NA according to pre-specified stopping criteria. The primary endpoint was biochemical relapse (HBV DNA >2000 IU/mL and alanine transaminase >2x upper limit of normal), which were also the re-treatment criteria.

RESULTS

Biochemical relapse occurred in 50 patients (48.3% at year 6). Multivariable analysis showed that higher HBV RNA levels (HR 1.34; P < 0.001) at the time of NA discontinuation were associated with increased biochemical relapse risk. The area under the curve of HBV RNA at the time of NA discontinuation for the incidence of biochemical relapse was 0.760 at 6 years. Six years after treatment discontinuation, all patients with HBV RNA levels ≥20 000 copies/mL at the end of treatment developed a biochemical relapse compared with 23.8% of patients with HBV RNA levels<1000 copies/mL (P < 0.001). More patients with HBV RNA levels <1000 copies/mL at end of treatment achieved loss of hepatitis B surface antigen than patients with higher levels (30.9% vs 1.6%; P = 0.027).

CONCLUSIONS

The HBV RNA level at end of treatment predicted biochemical relapse after treatment discontinuation and may be used to guide decisions on treatment discontinuation.

The relationship between hepatitis B virus serum DNA, RNA and quantitative hepatitis B surface antigen, and the predictive value for mother-to-child transmission: an observational cohort study

OBJECTIVE

To explore the relationships between hepatitis B virus (HBV) DNA, HBV RNA and hepatitis B surface antigen (HBsAg) and to evaluate their predictive value for mother-to-child transmission of HBV.

DESIGN

An observational cohort study.

SETTING

First Hospital of Jilin University.

POPULATION

HBsAg-positive and hepatitis B e antigen (HBeAg) -positive pregnant women were recruited.

METHODS

Blood samples were collected from mothers before delivery, and HBV infection of infants was evaluated at 7 months of age.

RESULTS

Overall, 268 mothers and 271 infants were enrolled. HBV DNA and HBsAg levels were correlated (r_s  = 0.699; P < 0.001), and HBV DNA (r_s  = 0.500; P < 0.001) and HBsAg (r_s  = 0.372; P < 0.001) were both correlated with HBV RNA. The areas under the curve for HBV DNA, HBsAg and HBV RNA for prediction of infection were 0.69 (95% CI 0.57-0.82), 0.63 (95% CI 0.51-0.76) and 0.65 (95% CI 0.52-0.78), respectively. Higher HBV DNA (odds ratio [OR] 4.77, 95% CI 1.44-15.86), higher HBsAg (OR 4.13, 95% CI 1.12-15.25) and higher HBV RNA (OR 3.19, 95% CI 1.09-9.32) were risk factors for HBV infection. Analysis of the HBV DNA-RNA-HBsAg Score revealed that it was an independent predictive factor for mother-to-child transmission (the OR of Score 3 was 8.81, 95% CI 2.79-27.82).

CONCLUSION

HBV DNA, HBV RNA and HBsAg were correlated in HBeAg-positive pregnant women. HBsAg could be considered as a substitute marker of HBV DNA for HBeAg-positive pregnant women in low-income regions. We should pay special attention to pregnant women with high levels of all three markers.

TWEETABLE ABSTRACT

HBsAg could be considered as a substitute marker of HBV DNA for HBeAg-positive pregnant women in low-income regions. Special attention should be given to pregnant women with high levels of all three markers (HBV DNA, HBV RNA and HBsAg).

Antiviral Activity and Pharmacokinetics of the Hepatitis B Virus (HBV) Capsid Assembly Modulator GLS4 in Patients With Chronic HBV Infection

Background

GLS4 is a first-in-class hepatitis B virus (HBV) capsid assembly modulator (class I) that can inhibit HBV replication by interfering with the assembly and disassembly of HBV nucleocapsid. Here, we evaluated its antiviral activity, pharmacokinetics, and tolerability in a double-blind, randomized, parallel, entecavir-controlled study.

Methods

Twenty-four patients with chronic HBV were randomized to receive a 28-day course of GLS4 (120 or 240 mg) and ritonavir (100 mg) combination (cohorts A and B, respectively) or entecavir treatment (cohort C) at a 1:1:1 ratio. Patients were followed up for 40 days in a phase 1b study.

Results

The GLS4/ritonavir combination was a tolerated combination for the treatment of chronic HBV infection. A total of 2, 3, and 3 subjects presented with alanine aminotransferase flare in cohorts A, B, and C, respectively. This contributed to the withdrawal of 1, 2, and 1 patient from cohorts A, B, and C, respectively. The mean C_trough of GLS4 was 205–218 ng/mL, which was approximately 3.7–3.9 times the 90% effective concentration (55.8 ng/mL), with a lower accumulation (accumulation rate, 1.1–2.0). In cohorts A, B, and C, the mean declines in HBV DNA after 28 days of treatment were −1.42, −2.13, and −3.5 log10 IU/mL; in hepatitis B surface antigen were −0.06, −0.14, and −0.33 log10 IU/mL; in pregenomic RNA were −0.75, −1.78, and −0.96 log10 copies/mL; and in hepatitis B core antigen were −0.23, −0.5, and −0.44 log10 U/mL, respectively.

Conclusions

Treatment with 120 mg GLS4 was tolerated and had antiviral activity in patients with chronic HBV infection.

Clinical Trials Registration

Chinese Clinical Trial Registry; CTR20160068. http://www.chinadrugtrials.org.cn.

Circulating Pregenomic Hepatitis B Virus RNA Is Primarily Full-length in Chronic Hepatitis B Patients Undergoing Nucleos(t)ide Analogue Therapy

Hepatitis B virus RNA is detectable in the serum of infected patients; however, the RNA species has been questioned. We tested 1827 specimens using a quantitative dual-target quantitative polymerase chain reaction assay and determined that full-length pregenomic RNA is the primary source. These results clarify the major identity of circulating HBV RNA species.

Assessment of hepatitis B virus pregenomic RNA in high and low viremic chronic hepatitis B patients

Aim of the study

Intrahepatic covalently closed circular DNA (cccDNA) is the main cause of hepatitis B virus (HBV) persistence. Therefore, a noninvasive serum biomarker that can reflect intrahepatic cccDNA is required for evaluation of HBV virological, biochemical activity and therapeutic response. Aim of the study was to assess serum hepatitis B pregenomic RNA in low viremia patients (HBV DNA < 2000 IU/ml) and high viremia (HBV DNA > 2000 IU/ml).

Material and methods

This study was carried out on two groups of chronic hepatitis B patients: group A - 40 patients with low viremia (HBV DNA < 2000 IU/ml); group B - 40 patients with high viremia (HBV DNA > 2000 IU/ml when diagnosed). They were assessed before treatment and after 6 months of treatment (entecavir 0.5 mg/24 h). Serum HBV pregenomic RNA was quantified using RT-PCR.

Results

Pregenomic RNA (pgRNA) was significantly lower in group A than in group B (before treatment). Moreover, it was significantly lower after 6 months of treatment than before treatment in group B. A significant positive correlation was observed between pgRNA and HBV DNA in groups A and B (before treatment); however, after 6 months of treatment of group B patients, although 35 patients had undetectable HBV DNA, they showed detectable levels of serum pgRNA and pgRNA > 4000 IU/ml was associated with virological and biochemical activity.

Conclusions

Serum HBV pregenomic RNA might be a promising marker for assessment of HBV virological, biochemical activity and evaluating therapeutic responses.

Hepatitis B Virus RNA as Early Predictor for Response to Pegylated Interferon Alpha in HBeAg-Negative Chronic Hepatitis B

BACKGROUND

Hepatitis B virus RNA (HBV-RNA) is a novel serum biomarker that correlates with transcription of intrahepatic covalently closed circular (cccDNA), which is an important target for pegylated interferon (PEG-IFN) and novel therapies for functional cure. We studied HBV-RNA kinetics following PEG-IFN treatment and its potential role as a predictor to response in HBeAg-negative chronic hepatitis B (CHB) patients.

METHODS

HBV-RNA levels were measured in 133 HBeAg-negative CHB patients treated in an international randomized controlled trial (PARC study). Patients received PEG-IFN α-2a for 48 weeks. HBV-RNA was measured from baseline through week 144. Response was defined as HBV-DNA <2000 IU/mL and ALT normalization at week 72. Kinetics of HBV-RNA were compared with HBV-DNA, HBsAg, and HBcrAg.

RESULTS

Mean HBV-RNA at baseline was 4.4 (standard deviation [SD] 1.2) log10 c/mL. At week 12, HBV-RNA declined by -1.6 (1.1) log10 c/mL. HBV-RNA showed a greater decline in responders compared to nonresponders early at week 12 (-2.0 [1.2] vs -1.5 [1.1] log10 c/mL, P = .04). HBV-RNA level above 1700 c/mL (3.2 log10 c/mL) had a negative predictive value of 91% at week 12 and 93% at week 24 (P = .01) for response. Overall, HBV-RNA showed a stronger correlation with HBV-DNA and HBcrAg (.82 and .80, P < .001) and a weak correlation with HBsAg (.25). At week 12, HBV-RNA was significantly lower among patients with lower HBsAg (<100 IU/mL) or HBsAg loss at week 144.

CONCLUSIONS

During PEG-IFN treatment for HBeAg-negative CHB, HBV-RNA showed a fast and significant decline that correlates with treatment response and HBsAg loss at long-term follow-up.

CLINICAL TRIALS REGISTRATION

NCT00114361.

Stability of hepatitis B virus pregenomic RNA in plasma specimens under various temperatures and storage conditions

Background

Hepatitis B virus (HBV) pregenomic RNA (pgRNA) has gained increasing attention owing to its role in replication of covalently closed circular DNA (cccDNA) in HBV. This marker has the potential to be used in clinical programs aimed to manage HBV infections. However, several reports on HBV pgRNA levels in clinical cases have conflicting results. RNA is easily degraded when exposed to heat and other environmental stressors. However, the stability of HBV pgRNA, during blood sample collection before the standard automated quantification, has never been estimated. This study aimed to demonstrate the effect of two different temperature conditions and storage durations on the stability of HBV pgRNA.

Method

Blood from forty patients with chronic hepatitis B infection, who also showed evidence of active HBV DNA replication, was collected and processed within 2 h of collection. Plasma from each patient was divided and stored at 4 °C and 25 °C (room temperature) for six different storage durations (0, 2, 6, 12, 24, and 48 h) and subsequently transferred to −80 °C for storage. The effect of multiple cycles of freezing and thawing of plasma at −20 °C or −80 °C was evaluated using samples from ten patients. Quantification of pgRNA from the samples was performed simultaneously, using the digital polymerase chain reaction (dPCR) method. The differences in pgRNA levels at baseline and each time point were compared using generalized estimating equation (GEE). A change greater than 0.5 log₁₀ copies/mL of pgRNA is considered clinically significant. Statistical analyses were conducted using Stata 16.0.

Results

The mean HBV pgRNA level in the initially collected plasma samples was 5.58 log₁₀copies/mL (ranging from 3.08 to 8.04 log₁₀ copies/mL). The mean pgRNA levels in samples stored for different time periods compared with the initial reference sample (time 0) significantly decreased. The levels of pgRNA for 6, 12, 24, and 48 h of storage reduced by −0.05 log₁₀ copies/mL (95% confidence interval (CI) −0.095 to −0.005, p = 0.03), −0.075 log₁₀ copies/mL (95% CI [−0.12 to −0.03], p = 0.001), −0.084 log₁₀ copies/mL (95% CI [−0.13 to −0.039], p =  < 0.001), and −0.120 log₁₀ copies/mL (95% CI [−0.17 to −0.076], p =  < 0.001), respectively. However, these changes were below 0.5 log₁₀ copies/mL and thus were not clinically significant. Compared with the samples stored at 4 °C, there were no significant differences in pgRNA levels in samples stored at 25 °C for any of the storage durations (−0.01 log₁₀ copies/mL; 95% CI [−0.708 to 0.689], p = 0.98). No significant difference in the levels of pgRNA was observed in the plasma samples, following four freeze-thaw cycles at −20 °C and −80 °C.

Conclusion

The plasma HBV pgRNA level was stable at 4 °C and at room temperature for at least 48 h and under multiple freeze-thaw cycles. Our results suggest that pgRNA is stable during the process of blood collection, and therefore results of pgRNA quantification are reliable.

What drives the dynamics of HBV RNA during treatment?

Hepatitis B virus RNA (HBV RNA)-containing particles are encapsidated pre-genomic RNA (pgRNA) detectable in chronically infected patients in addition to virions (HBV DNA) that have been suggested as a marker of the treatment efficacy. This makes promising the use of core protein allosteric modulators, such as RG7907, which disrupt the nucleocapsid assembly and profoundly reduce HBV RNA. Here, we developed a multiscale model of HBV extending the standard viral dynamic models to analyse the kinetics of HBV DNA and HBV RNA in 35 patients treated with RG7907 for 28 days. We compare the predictions with those obtained in patients treated with the nucleotide analog tenofovir. RG7907 blocked 99.3% of pgRNA encapsidation (range: 92.1%-99.9%) which led to a decline of both HBV DNA and HBV RNA. As a consequence of its mode of action, the first phase of decline of HBV RNA was rapid, uncovering the clearance of viral particles with half-life of 45 min. In contrast, HBV DNA decline was predicted to be less rapid, due to the continuous secretion of already formed viral capsids (t_1/2  = 17 ± 6 h). After few days, both markers declined at the same rate, which was attributed to the loss of infected cells (t_1/2  ≅ 6 ± 0.8 days). By blocking efficiently RNA reverse transcription but not its encapsidation, nucleotide analog in contrast was predicted to lead to a transient accumulation of HBV RNA both intracellularly and extracellularly. The model brings a conceptual framework for understanding the differences between HBV DNA and HBV RNA dynamics. Integration of HBV RNA in viral dynamic models may be helpful to better quantify the treatment effect, especially in viral-suppressed patients where HBV DNA is no longer detectable.

Rapid Turnover of Hepatitis B Virus Covalently Closed Circular DNA Indicated by Monitoring Emergence and Reversion of Signature-Mutation in Treated Chronic Hepatitis B Patients

BACKGROUND AND AIMS

Hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) plays a pivotal role in the establishment and persistence of HBV infection. Understanding the turnover time of preexisting cccDNA pools would be helpful in designing strategies to clear HBV by fully blocking the de novo generation of cccDNA.

APPROACH AND RESULTS

In this study, we retrospectively monitored the emergence and reversion of the rtM204I/V mutant, a signature lamivudine resistance (LAMR ) mutation serving as a biomarker of cccDNA turnover in liver biopsies and longitudinal serum samples from two clinical trials. Methodologies were optimized to differentially isolate and sequence HBV virion DNA, cccDNA, and HBV RNA from clinical samples. A strong correlation was observed between LAMR composition of cccDNA with that of serum and intrahepatic HBV RNA in paired liver and serum samples (r = 0.96 and 0.90, respectively), suggesting that serum HBV RNA can serve as a surrogate marker of cccDNA genetic composition when liver biopsies are unavailable. LAMR mutations emerged and increased from undetectable to 40%-90% within 16-28 weeks in serum HBV RNA from telbivudine-treated patients experiencing virological breakthrough. Similarly, in lamivudine-resistant patients who switched to interferon therapy, serum HBV-RNA population bearing 100% LAMR mutations fully reversed back to wild type within 24-48 weeks.

CONCLUSIONS

The genetic composition dynamics of serum HBV RNA and biopsy cccDNA in treated HBV patients indicates that cccDNA turnover occurs relatively rapidly (several months), offering a possibility of HBV cure with finite therapy through completely blocking cccDNA replenishment.

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.

Reverse transcriptase droplet digital PCR vs reverse transcriptase quantitative real-time PCR for serum HBV RNA quantification

Serum hepatitis B virus (HBV) RNA is a novel marker reflecting the activity of covalently closed circular DNA. However, the methodology for detecting HBV RNA has been a technical challenge. In this study, the performance of reverse transcription droplet digital polymerase chain reaction (RT-ddPCR) for quantifying HBV RNA was compared with that of reverse transcription quantitative real-time PCR (RT-qPCR) in serum samples collected from treatment-naïve patients with different phases of chronic hepatitis B (CHB). A total of 417 serum samples, including 136 HBeAg-positive CHB and 281 HBeAg-negative CHB were examined. HBV RNA levels measured by RT-ddPCR and RT-qPCR showed a high degree of linearity and quantitative correlation. The limit of detections of RT-ddPCR and RT-qPCR assays were 102 and 103 copies/mL, respectively. Our results also demonstrated that RT-ddPCR was superior to RT-qPCR in terms of its consistency for quantifying HBV RNA across all concentrations. In the HBeAg-positive group, serum HBV RNA levels based on RT-ddPCR were moderately correlated with HBV DNA (r = 0.591, P < .001) and HBsAg (r = 0.502, P < .001). Among patients with HBeAg-negative CHB, serum HBV RNA levels were moderately correlated with HBV DNA (r = 0.603, P < .001) but had weak correlation with HBsAg (r = 0.203, P = .001). In summary, RT-ddPCR could enhance the sensitivity of serum HBV RNA detection, particularly among the HBeAg-negative group with low viral loads. Thus, RT-ddPCR could serve as an optimal method for HBV RNA quantification in clinical practice.

Biogenesis and molecular characteristics of serum hepatitis B virus RNA

HBV is an enveloped DNA virus that replicates its DNA genome via reverse transcription of a pregenomic (pg) RNA intermediate in hepatocytes. Interestingly, HBV RNA can be detected in virus-like particles in chronic hepatitis B (CHB) patient serum and has been utilized as a biomarker for intrahepatic cccDNA activity in treated patients. However, the biogenesis and molecular characteristics of serum HBV RNA remain to be fully defined. In this study, we found that the encapsidated serum HBV RNA predominately consists of pgRNA, which are detergent- and ribonuclease-resistant. Through blocking HBV DNA replication without affecting pgRNA encapsidation by using the priming-defective HBV mutant Y63D or 3TC treatment, we demonstrated that the cell culture supernatant contains a large amount of pgRNA-containing nonenveloped capsids and a minor population of pgRNA-containing virions. The formation of pgRNA-virion requires both capsid assembly and viral envelope proteins, which can be inhibited by capsid assembly modulators and an envelope-knockout mutant, respectively. Furthermore, the pgRNA-virion utilizes the multivesicular body pathway for egress, in a similar way as DNA-virion morphogenesis. Northern blotting, RT-PCR, and 3' RACE assays revealed that serum/supernatant HBV pgRNA are mainly spliced and devoid of the 3'-terminal sequences. Furthermore, pgRNA-virion collected from cells treated with a reversible HBV priming inhibitor L-FMAU was unable to establish infection in HepG2-NTCP cells. In summary, serum HBV RNA is secreted in noninfectious virion-like particle as spliced and poly(A)-free pgRNA. Our study will shed light on the molecular biology of serum HBV RNA in HBV life cycle, and aid the development of serum HBV RNA as a novel biomarker for CHB diagnosis and treatment prognosis.

Recent Advances in Understanding, Diagnosing, and Treating Hepatitis B Virus Infection

Chronic hepatitis B virus (HBV) infection affects 292 million people worldwide and is associated with a broad range of clinical manifestations including cirrhosis, liver failure, and hepatocellular carcinoma (HCC). Despite the availability of an effective vaccine HBV still causes nearly 900,000 deaths every year. Current treatment options keep HBV under control, but they do not offer a cure as they cannot completely clear HBV from infected hepatocytes. The recent development of reliable cell culture systems allowed for a better understanding of the host and viral mechanisms affecting HBV replication and persistence. Recent advances into the understanding of HBV biology, new potential diagnostic markers of hepatitis B infection, as well as novel antivirals targeting different steps in the HBV replication cycle are summarized in this review article.

Comparison of Serum Hepatitis B Virus RNA Levels and Quasispecies Evolution Patterns between Entecavir and Pegylated-Interferon Mono-treatment in Chronic Hepatitis B Patients

Hepatitis B virus (HBV) RNA may independently predict virological and serological response. This study aimed to compare dynamic changes in serum HBV RNA levels and HBV quasispecies evolution patterns between entecavir and pegylated-interferon mono-treatment in chronic hepatitis B patients and to determine the clinical significance during treatment. TaqMan real-time PCR was used for quantitative analysis. HBV RNA levels were retrospectively determined in serial serum samples from 178 chronic hepatitis B patients who received either entecavir or pegylated-interferon treatment.

Hepatitis B virus (HBV) RNA may independently predict virological and serological response. This study aimed to compare dynamic changes in serum HBV RNA levels and HBV quasispecies evolution patterns between entecavir and pegylated-interferon mono-treatment in chronic hepatitis B patients and to determine the clinical significance during treatment. TaqMan real-time PCR was used for quantitative analysis. HBV RNA levels were retrospectively determined in serial serum samples from 178 chronic hepatitis B patients who received either entecavir or pegylated-interferon treatment. Both serum HBV DNA and RNA quasispecies were analyzed via next-generation sequencing. Receiver operating characteristics (ROC) analysis was performed to evaluate the prediction value of individual biomarkers for hepatitis B e antigen (HBeAg) seroconversion. Patients who received pegylated-interferon treatment showed stronger declines in HBV RNA levels than did those who received entecavir treatment. Serum HBV RNA levels were lower in patients with subsequent HBeAg seroconversion. At baseline, the level of HBV RNA was better than other indicators in predicting HBeAg seroconversion. Moreover, the predictive value of serum HBV RNA levels was better in the entecavir group. Baseline HBV RNA exhibited a significantly higher genetic diversity than HBV DNA and had a significant decline after 4 weeks of entecavir treatment. Higher baseline genetic diversity may result in a better outcome in pegylated-interferon-treated patients. Serum HBV RNA levels showed different decline kinetics, and HBV RNA quasispecies showed different evolution patterns in entecavir and pegylated-interferon mono-treatment. Taken together, serum HBV RNA may serve as a promising biomarker of HBeAg seroconversion in patients during antiviral treatment.

HBcrAg and pg RNA and the therapeutic effect in HBeAg-positive patients receiving anti-viral therapy, baseline serum HBV-RNA is a powerful predictor of response

We used HBV core antigen (HbcrAg), pre-genomic RNA (pg RNA) and other biomarkers to evaluate the therapeutic effect in HBV infected patients receiving anti-viral therapy. 127HBeAg-positive patients were enrolled: 35 patients received nucleotide therapy, 14 patients received interferon and 78 patients received combination therapy with both. HBcrAg, pg RNA and other biomarkers were detected at different time points, we defined the decreased titre of HBcrAg and HBeAg from baseline to 6 and baseline to 12 months as ∆HBcrAg and ∆HBeAg, which were used to predict HBeAg seroconversion. Furthermore, we used the time-dependent receiver operator curve of different markers to analyse HBeAg seroconversion. For HBeAg seroconversion: at 6 months, 0.75 log₁₀ U/mL of ∆HBcrAg and 1.47 log₁₀ PEI U/mL of ∆HBeAg showed maximum predictive value in receiver operator curve analysis (Youden's index values for area under the curve of 0.687 and 0.646, respectively). At 12 months, 2.05 log₁₀ U/mL of ∆HBcrAg and 1.92 log₁₀ PEI U/mL of ∆HBeAg showed improved prediction (maximum Youden's index values, with areas under the curve of 0.688 and 0.698, respectively).pg RNA was a better predictor of outcome due and the concentrations of 6.20 log₁₀ I U/mL of pg RNA and 8.0 log₁₀ U/mL of HBcrAg were cut-off values for response in a Kaplan-Meier curve analysis. Our results may be used to identify the pg RNA concentration in patients at baseline and ∆HBcrAg during therapy who are likely to achieve HBeAg seroconversion according to the cut-off value at different time points, thus helping to evaluate the therapeutic effect.

Factors associated with the biphasic kinetics of serum HBV RNA in patients with HBeAg-positive chronic hepatitis B treated with nucleos(t)ide analogues

BACKGROUND

Serum hepatitis B virus (HBV) RNA is a novel biomarker for evaluating treatment response. Detailed information regarding serum HBV RNA kinetics during treatment with nucleos(t)ide analogues (NAs) is limited.

AIMS

To ascertain serum HBV RNA kinetics during long-term NA treatment and identify associated factors.

METHODS

We enrolled 76 HBeAg-positive chronic hepatitis B patients receiving NA from randomised controlled trials. Laboratory assays were undertaken every 3 months. Factors associated with serum HBV RNA kinetics were identified by generalised estimating equations.

RESULTS

Baseline serum HBV RNA was 8.5 ± 1.0 log₁₀  copies/mL. Decline in serum HBV RNA during NA therapy was biphasic: the first phase (HBV DNA detectable) had a fast decrease (median slope, -0.207 log₁₀  copies/mL/month) and was followed by a second phase (HBV DNA undetectable) with slow decrease (median slope, -0.071 log₁₀  copies/mL/month). In the first phase, factors independently associated with lower initial serum HBV RNA were male sex (OR, 0.685, P = 0.044), low baseline HBsAg (OR, 0.525, P = 0.001) and rapid virological response (RVR) (OR, 0.624, P = 0.031). In the second phase, only RVR was independently associated with serum HBV RNA kinetics, including its lower initial level (OR, 0.694, P = 0.043) and greater decline (OR, 0.966, P = 0.002). Based on viral dynamics, time needed to achieve undetectable serum HBV RNA from baseline was 43.56 (IQR: 29.49-66.40) months.

CONCLUSION

RVR was a significant determinant for biphasic decline in serum HBV RNA during NA treatment, which significantly influenced the treatment duration required to achieve undetectable serum HBV RNA.

Efficacy of a combination of HBV RNA and HBeAg in predicting HBeAg seroconversion in patients treated with entecavir for 144 weeks

BACKGROUND

In some previous studies, serum hepatitis B virus RNA (HBV RNA) was proposed as an HBV viral marker during therapy. However, the dynamic change of HBV RNA, the correlation of HBV RNA with cccDNA, and the combination of HBV RNA with known HBV markers in predicting entecavir (ETV) treatment outcome in the same cohort are rarely reported.

METHODS

A total of 111 HBeAg-positive patients were enrolled in our study. The dynamic changes of serum HBV RNA and the correlation of HBV RNA with other HBV markers were investigated in the early treatment period of 144-week ETV treatment. Intrahepatic cccDNA was detected at baseline and week 48. Receiver operating characteristic analyses were used to identify HBV RNA levels associated with HBeAg seroconversion.

RESULTS

The serum HBV RNA levels decreased more rapidly in patients with HBeAg seroconversion than those without HBeAg seroconversion. The levels of HBV RNA decreased slower compared with the serum HBV DNA, irrespective of whether the patients achieved HBeAg seroconversion or not. Although the serum HBV RNA was positively correlated with cccDNA at baseline among all patients, no significant correlation was observed in the patients with HBeAg seroconversion at week 48 (r=0.094, P=0.588). The area under the receiver operating characteristic (AUROC) of HBV RNA and HBeAg at week 24 was 0.754 and 0.800, respectively. The AUROC of the HBV RNA and HBeAg combination had a higher value (AUROC=0.821).

CONCLUSIONS

The level of HBV RNA at week 24 was a powerful predictor of HBeAg seroconversion in HBeAg-positive patients after 144-week ETV treatment, while the combination of HBV RNA and HBeAg was superior to HBV RNA alone in predicting HBeAg seroconversion.

Serum hepatitis B virus RNA predicts response to peginterferon treatment in HBeAg-positive chronic hepatitis B

Hepatitis B virus (HBV) RNA in serum is a novel biomarker that reflects cccDNA activity. We investigated whether HBV RNA can predict serological response to peginterferon (PEG-IFN) treatment. Serum HBV RNA levels were retrospectively measured at weeks 0, 12, 24 and 52 of therapy and after treatment discontinuation (week 78) in 266 HBeAg-positive chronic HBV patients who had participated in a global randomized controlled trial (HBV99-01 study). Patients received 52 weeks PEG-IFN monotherapy (n = 136) or PEG-IFN and lamivudine (n = 130). The primary end point was HBeAg loss 24 weeks after PEG-IFN discontinuation. At baseline, the mean serum level of HBV RNA was 6.8 (SD 1.2) log c/mL. HBV RNA levels declined to 4.7 (1.7) log c/mL after one year of PEG-IFN therapy alone and to 3.3 (1.2)log c/mL after combination therapy. From week 12 onward, HBV RNA level was significantly lower in patients who achieved HBeAg loss at the end of follow-up as compared to those who did not, regardless of treatment allocation (week 12:4.4 vs 5.1 log c/mL, P = .01; week 24:3.7 vs 4.9 log c/mL, P < .001). The performance of a multivariable model based on HBV RNA level was comparable at week 12 (AUC 0.68) and 24 (AUC 0.72) of therapy. HBV RNA level above 5.5 log c/mL at week 12 showed negative predictive values of 93/67/90/64% for HBV genotypes A/B/C/D for the prediction of HBeAg loss. In conclusion, HBV RNA in serum declines profoundly during PEG-IFN treatment. Early on-treatment HBV RNA level may be used to predict nonresponse.