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

Mechanism of interferon alpha therapy for chronic hepatitis B and potential approaches to improve its therapeutic efficacy

Hepatitis B virus (HBV) chronically infects 296 million people worldwide and causes more than 820,000 deaths annually due to cirrhosis and hepatocellular carcinoma. Current standard-of-care medications for chronic hepatitis B (CHB) include nucleos(t)ide analogue (NA) viral DNA polymerase inhibitors and pegylated interferon alpha (PEG-IFN-α). NAs can efficiently suppress viral replication and improve liver pathology, but not eliminate or inactivate HBV covalently closed circular DNA (cccDNA). CCC DNA is the most stable HBV replication intermediate that exists as a minichromosome in the nucleus of infected hepatocyte to transcribe viral RNA and support viral protein translation and genome replication. Consequentially, a finite duration of NA therapy rarely achieves a sustained off-treatment suppression of viral replication and life-long NA treatment is most likely required. On the contrary, PEG-IFN-α has the benefit of finite treatment duration and achieves HBsAg seroclearance, the indication of durable immune control of HBV replication and functional cure of CHB, in approximately 5% of treated patients. However, the low antiviral efficacy and poor tolerability limit its use. Understanding how IFN-α suppresses HBV replication and regulates antiviral immune responses will help rational optimization of IFN therapy and development of novel immune modulators to improve the rate of functional cure. This review article highlights mechanistic insight on IFN control of HBV infection and recent progress in development of novel IFN regimens, small molecule IFN mimetics and combination therapy of PEG-IFN-α with new direct-acting antivirals and therapeutic vaccines to facilitate the functional cure of CHB.

[Research progress of biomarkers of hepatitis B virus and clinical significance]

The infection of Hepatitis B virus (HBV) can result in severe consequences, including chronic hepatitis, liver fibrosis, cirrhosis, and even liver cancer. Effective antiviral treatment has the potential to slow down the progression of the disease. HBV serum biomarkers play a crucial role in the dynamic management of chronic hepatitis B (CHB) patients. However, the conventional hepatitis B virus markers, such as hepatitis B serologic testing and HBV DNA, are insufficient to meet the clinical requirements. This review provided a comprehensive overview of the current research on the quantification of HBsAg and anti-HBc, HBV RNA and HBV core-associated antigen, which summarized the crucial role these markers play in the administration of antiviral medications, predicting the efficacy of treatment and anticipating the likelihood of virologic rebound following drug cessation, as well as assessing disease progression in CHB patients.

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.

Interpreting Serogical Markers in Hepatitis B Virus Infection

Hepatitis B virus (HBV) is considered a global health-related problem. The World Health Organization estimates an incidence of approximately 1.5 million new cases annually despite an available effective vaccine, and approximately 296 million people worldwide are living with chronic hepatitis B. This large number of patients require continuous monitoring of the treatment efficacy, disease progression, and screening for the HBV-related liver complications. Recently, it has become more evident that we need better predictive markers to allow treatment cessation when there is a reduced risk of viral reactivation, in addition to the present need to predict disease outcome and improve the management of people living with chronic hepatitis B. Novel HBV biomarkers are focused on in this minireview. These new markers include quantification of serum HBV RNA, hepatitis B core–related antigen, quantitative hepatitis B surface antigen, quantitative anti–hepatitis B core antigen, and detection of HBV nucleic acid–related antigen. The target of finding new markers for HBV replication is to provide crucial clinical data in a noninvasive way for detecting the replicative and transcriptional activity of the virus. This may support better management of patients compared with the criterion-standard invasive marker for detecting the intrahepatic replication and transcription of HBV, which is the quantification of covalently closed circular DNA.

Hepatitis B virus serum RNA transcript isoform composition and proportion in chronic hepatitis B patients by nanopore long-read sequencing

Introduction

Serum hepatitis B virus (HBV) RNA is a promising new biomarker to manage and predict clinical outcomes of chronic hepatitis B (CHB) infection. However, the HBV serum transcriptome within encapsidated particles, which is the biomarker analyte measured in serum, remains poorly characterized. This study aimed to evaluate serum HBV RNA transcript composition and proportionality by PCR-cDNA nanopore sequencing of samples from CHB patients having varied HBV genotype (gt, A to F) and HBeAg status.

Methods

Longitudinal specimens from 3 individuals during and following pregnancy (approximately 7 months between time points) were also investigated. HBV RNA extracted from 16 serum samples obtained from 13 patients (73.3% female, 84.6% Asian) was sequenced and serum HBV RNA isoform detection and quantification were performed using three bioinformatic workflows; FLAIR, RATTLE, and a GraphMap-based workflow within the Galaxy application. A spike-in RNA variant (SIRV) control mix was used to assess run quality and coverage. The proportionality of transcript isoforms was based on total HBV reads determined by each workflow.

Results

All chosen isoform detection workflows showed high agreement in transcript proportionality and composition for most samples. HBV pregenomic RNA (pgRNA) was the most frequently observed transcript isoform (93.8% of patient samples), while other detected transcripts included pgRNA spliced variants, 3' truncated variants and HBx mRNA, depending on the isoform detection method. Spliced variants of pgRNA were primarily observed in HBV gtB, C, E, or F-infected patients, with the Sp1 spliced variant detected most frequently. Twelve other pgRNA spliced variant transcripts were identified, including 3 previously unidentified transcripts, although spliced isoform identification was very dependent on the workflow used to analyze sequence data. Longitudinal sampling among pregnant and post-partum antiviral-treated individuals showed increasing proportions of 3' truncated pgRNA variants over time.

Conclusions

This study demonstrated long-read sequencing as a promising tool for the characterization of the serum HBV transcriptome. However, further studies are needed to better understand how serum HBV RNA isoform type and proportion are linked to CHB disease progression and antiviral treatment response.

CXCL13 variant predicts pegylated-interferon α treatment response in HBeAg-positive chronic hepatitis B patients

As a key immune cytokine, C-X-C motif chemokine ligand 13 (CXCL13) has been reported to play critical roles in immune control of hepatitis B virus (HBV) infection. We aimed to screen single-nucleotide polymorphisms (SNPs) of CXCL13 for predicting response to pegylated interferon-alpha (PegIFNα) therapy of chronic hepatitis B (CHB) patients. Two independent cohorts with a total of 945 (Cohort 1, n = 238; Cohort 2, n = 707) hepatitis B e antigen (HBeAg)-positive CHB patients treated with PegIFNα were enrolled in this retrospective cohort study. Eight candidate SNPs were selected through gene-wide SNP mining within or flanking CXCL13. A polygenic score (PGS) was utilized to assess the cumulative effects of multiple SNPs. The associations of candidate SNPs and PGS with combined response (CR, defined as the combination of HBeAg seroconversion and HBV DNA level <3.3log10 IU/mL) and hepatitis B surface antigen (HBsAg) level were evaluated. Among the eight candidate SNPs, rs76084459 which is located at upstream of CXCL13 was significantly associated with both CR (p = 0.002) and HBsAg level (p = 0.015). A PGS integrating CXCL13_rs76084459 and five other SNPs, which were previously identified as predictors of PegIFNα treatment response, was further strongly correlated with CR (p = 1.759 × 10-10 ) and HBsAg level (p = 0.004). This study demonstrated that CXCL13_rs76084459 can predict response to PegIFNα treatment of HBeAg-positive CHB patients. A PGS composed of six SNPs including CXCL13_rs76084459 predicts PegIFNα treatment response better.

PgRNA kinetics predict HBsAg reduction in pregnant chronic hepatitis B carriers after treatment cessation

Background

Pregenomic RNA (pgRNA) and hepatitis B core-related antigen (HBcrAg) play significant roles in predicting discontinuing treatment outcomes. However, their role in pregnancy has rarely been reported. We aimed to evaluate the performance of pgRNA and HBcrAg kinetics in predicting HBeAg seroconversion and HBsAg reduction postpartum in HBeAg-positive pregnant women.

Methods

Pregnant HBeAg-positive patients receiving antiviral prophylaxis and ceasing treatment postpartum were included. PgRNA and HBcrAg levels were measured before treatment, at 32 weeks of gestation, and at treatment withdrawal postpartum. Other virological and biochemical parameters were regularly examined until 96 weeks postpartum.

Results

Of 76 pregnant chronic hepatitis B (CHB) carriers with a median treatment duration of 18.1 weeks, HBeAg seroconversion and HBsAg reduction >0.3 log₁₀ IU/mL at 96 weeks postpartum occurred in 8 (10.5%) and 13 (17.1%) patients, respectively. HBsAg correlated most strongly with pgRNA, while HBeAg correlated most strongly with HBcrAg. Multivariable regression analysis revealed that postpartum pgRNA decline and peak ALT levels were independent predictors of HBsAg reduction. The area under the curve of the regression model was 0.79 and reached as high as 0.76 through bootstrapping validation. The calibration plot showed that the nomogram had a performance similar to that of the ideal model. A decision tree was established to facilitate application of the nomogram. In addition, HBcrAg kinetics, as an independent predictor, performed poorly in predicting HBeAg seroconversion.

Conclusions

Postpartum pgRNA decline together with peak ALT levels may identify patients with a higher probability of HBsAg reduction after treatment cessation postpartum among pregnant CHB carriers receiving antiviral prophylaxis.

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.

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).

Standardized Hepatitis B Virus RNA Quantification in Untreated and Treated Chronic Patients: a Promising Marker of Infection Follow-Up

The measurement and interpretation of HBV DNA and RNA levels in HBV infected patients treated with antiviral therapy supports the objective of HBV disease management. Here, we quantified circulating HBV RNA through a standardized and sensitive assay in follow-up samples from both naive and treated patients as a marker of infection evolution. HBV DNA (HBV DNA for use in Cobas 6800/8800 Automated Roche Molecular Systems), RNA (Roche HBV RNA Investigational Assay for use in the Cobas 6800/8800; Roche), HBeAg and HBsAg (Elycsys HBsAg chemiluminescence immunoassay by Cobas 8000; Roche), and core-related antigen (Lumipulse G chemiluminescence assay; Fujirebio) levels were measured in cohorts of untreated or nucleos(t)ide treated, HBV-infected subjects in an outpatient hospital setting. HBV DNA levels in untreated people were 3.6 log10 higher than corresponding RNA levels and were stable over 5 years of observation. While only five of 52 treated patients had DNA levels below the lower limit of quantification (10 IU/mL) at the end of follow-up, 13 had HBV RNA levels persistently above this limit, including eight with undetectable DNA. In samples with undetectable core-related antigen we observed a median HBsAg titer 2.7-fold higher than in samples with undetectable RNA (adjusted P = 0.012). Detectable HBV RNA with undetectable HBV DNA was a negative predictor of HBsAg decrease to a level ≤100 IU/mL (P = 0.03). In naive patients the difference between HBV DNA and RNA was higher than previously reported. HBV RNA rapidly decreased during treatment. However, in some cases, it was detectable even after years of effective therapy, being a negative predictor of HBsAg decrease. The investigational RNA assay for use on the Cobas 6800/8800 instruments is a sensitive and standardized method that could be applied in general management of HBV infection. IMPORTANCE This study focused on the quantification of circulating HBV RNA by using a standardized and sensitive assay. Thanks to this system we observed a higher difference between circulating HBV DNA and RNA than previously reported. In treated patients, HBV RNA decreased together with DNA, although some patients presented detectable levels even after years of successful antiviral treatment, suggesting a persistent viral transcription. Of note, the detection of viral RNA when HBV DNA is undetectable was a negative predictor of HBsAg decrease to a level ≤100 IU/mL. This assay could be extremely helpful in HBV patients management to study viral transcription and to identify those treated patients that may achieve sustained viral suppression.

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.

Research progress in hepatitis B virus covalently closed circular DNA

Hepatitis B virus (HBV) infections are a global public health issue. HBV covalently closed circular DNA (cccDNA), the template for the transcription of viral RNAs, is a key factor in the HBV replication cycle. Notably, many host factors involved in HBV cccDNA epigenetic modulation promote the development of hepatocellular carcinoma (HCC). The HBV cccDNA minichromosome is a clinical obstacle that cannot be efficiently eliminated. In this review, we provide an update on the advances in research on HBV cccDNA and further discuss factors affecting the modulation of HBV cccDNA. Hepatitis B virus X protein (HBx) contributes to HBV cccDNA transcription and the development of hepatocarcinogenesis through modulating host epigenetic regulatory factors, thus linking the cccDNA to hepatocarcinogenesis. The measurable serological biomarkers of continued transcription of cccDNA, the effects of anti-HBV drugs on cccDNA, and potential therapeutic strategies targeting cccDNA are discussed in detail. Thus, this review describes new insights into HBV cccDNA mechanisms and therapeutic strategies for cleaning cccDNA, which will benefit patients with liver diseases.

A Missense Variant in Granulysin is Associated with the Efficacy of Pegylated-Interferon-Alpha Therapy in Chinese Patients with HBeAg-Positive Chronic Hepatitis B

PURPOSE

Granulysin (GNLY) is a cytotoxic granule that has been reported to have various antimicrobial activities. We evaluated the association between a missense variant in GNLY (rs11127) and treatment efficacy of pegylated interferon-alpha (PegIFNα) or nucleos(t)ide analogs (NUCs) in patients with chronic hepatitis B (CHB).

PATIENTS AND METHODS

We included a total of 1823 patients with hepatitis B e antigen (HBeAg)-positive CHB (954 patients treated with PegIFNα and 869 patients treated with NUCs) in four Phase IV multicenter randomized controlled trials. The association of the GNLY rs11127 genotype with the combined response (CR), defined as HBeAg seroconversion and hepatitis B virus (HBV) DNA level <2000 IU/mL was evaluated. A polygenic score (PGS) was constructed to evaluate the cumulative effect of multiple single-nucleotide polymorphisms (SNPs), including rs11127 and several other SNPs, STAT4 rs7574865, CFB rs12614, and CD55 rs28371597, which were reported to be associated with CR.

RESULTS

GNLY rs11127 was significantly associated with CR in patients treated with PegIFNα. The CR rate in patients with the rs11127 CC genotype was higher than that with the CT or TT genotype (40.98% vs 30.34% or 27.09%, P = 0.003). Furthermore, a PGS integrating GNLY rs11127 and three other SNPs was significantly associated with CR in PegIFNα-treated patients (P < 0.001). However, no significant correlation was found between GNLY rs11127 and CR in NUCs-treated patients.

CONCLUSION

GNLY rs11127 is an independent biomarker for predicting the response to PegIFNα therapy in HBeAg-positive CHB patients. Furthermore, the PGS, including GNLY rs11127, provides new insights for individualized treatment in clinical practice.

How to interpret viral markers in the management of chronic hepatitis B infection

BACKGROUND

Hepatitis B virus (HBV) infection is a global public health issue with several unsolved clinical challenges. As multiple new drugs are under development, HBV markers are gaining importance for both diagnostic and prognostic purposes.

OBJECTIVES

This review summarizes the most important data on the usefulness of HBV markers in the natural history of this infection, and in predicting clinical and treatment outcomes.

SOURCES

Selected peer-reviewed publications on HBV markers published between January 2009 and July 2021.

CONTENT

In addition to the classical markers (e.g. HBV-DNA), newer ones, such as quantitative HBsAg, HBcrAg, HBV-RNA and quantitative anti-HBc, have proven useful for predicting events within the natural history of HBV infection, the development of complications (e.g. hepatocellular carcinoma) and the response to antiviral therapy. Most data regarding the response to treatment have been related to nucleos(t)ide analogues, whereas evidence on new therapeutic agents, such as capsid assembly modulators or small interference RNAs, is promising, but still scarce.

IMPLICATIONS

Knowledge on the use of viral markers is a key factor for optimizing the clinical appraisal of HBV infection. The new markers have an enhanced ability to predict clinical outcomes. Further studies should expand the current evidence on the use of markers in relation to antiviral agents currently under evaluation. Wide availability of these markers in regions with a high incidence of HBV infection is of paramount importance.

Critical Updates on Chronic Hepatitis B Virus Infection in 2021

Chronic hepatitis B virus (HBV) infection is a global healthcare burden in the form of chronic liver disease, cirrhosis, liver failure and liver cancer. There is no definite cure for the virus and even though extensive vaccination programs have reduced the burden of liver disease in the future population, treatment options to eradicate the virus from the host are still lacking. In this review, we discuss in detail current updates on the structure and applied biology of the virus in the host, examine updates to current treatment and explore novel and state-of-the-art therapeutics in the pipeline for management of chronic HBV. Furthermore, we also specifically review clinical updates on HBV-related acute on chronic liver failure (ACLF). Current treatments for chronic HBV infection have seen important updates in the form of considerations for treating patients in the immune tolerant phase and some clarity on end points for treatment and decisions on finite therapy with nucleos(t)ide inhibitors. Ongoing cutting-edge research on HBV biology has helped us identify novel target areas in the life cycle of the virus for application of new therapeutics. Due to improvements in the area of genomics, the hope for therapeutic vaccines, vector-based treatments and focused management aimed at targeting host integration of the virus and thereby a total cure could become a reality in the near future. Newer clinical prognostic tools have improved our understanding of timing of specific treatment options for the catastrophic syndrome of ACLF secondary to reactivation of HBV. In this review, we discuss in detail pertinent updates regarding virus biology and novel therapeutic targets with special focus on the appraisal of prognostic scores and treatment options in HBV-related ACLF.

Novel Biomarkers of Hepatitis B Virus and Their Use in Chronic Hepatitis B Patient Management

Even though an approved vaccine for hepatitis B virus (HBV) is available and widely used, over 257 million individuals worldwide are living with chronic hepatitis B (CHB) who require monitoring of treatment response, viral activity, and disease progression to reduce their risk of HBV-related liver disease. There is currently a lack of predictive markers to guide clinical management and to allow treatment cessation with reduced risk of viral reactivation. Novel HBV biomarkers are in development in an effort to improve the management of people living with CHB, to predict disease outcomes of CHB, and further understand the natural history of HBV. This review focuses on novel HBV biomarkers and their use in the clinical setting, including the description of and methodology for quantification of serum HBV RNA, hepatitis B core-related antigen (HBcrAg), quantitative hepatitis B surface antigen (qHBsAg), including ultrasensitive HBsAg detection, quantitative anti-hepatitis B core antigen (qAHBc), and detection of HBV nucleic acid-related antigen (HBV-NRAg). The utility of these biomarkers in treatment-naïve and treated CHB patients in several clinical situations is further discussed. Novel HBV biomarkers have been observed to provide critical clinical information and show promise for improving patient management and our understanding of the natural history of HBV.

Hepatitis b infection: progress in identifying patients most likely to respond to peginterferon alfa

Introduction: Despite the disadvantage of side effects, pegylated interferon alpha (Peg-IFN α) remains an indispensable agent for chronic hepatitis B (CHB) due to its immunomodulatory effect. The selection of a patient most likely to have a favorable response becomes an essential issue for Peg-IFN α therapy.Areas covered: Recent progress in the prediction of the treatment response to Peg-IFN α.Expert opinion: Before Peg-IFN α therapy, baseline host and viral factors, including female sex, younger age, a high alanine aminotransferase level, HBV genotype A or B, and low viral load, predict a favorable response. In addition, on-treatment viral kinetics of hepatitis B surface antigen (HBsAg), e antigen (HBeAg) and HBV DNA help clinicians determine whether to continue or discontinue Peg-IFN α therapy. The novel HBV markers hepatitis B core-related antigen and HBV RNA have recently been investigated as useful predictors. The limited efficacy of Peg-IFN α monotherapy facilitated the development of new strategies of 'add-on' or 'switch to' Peg-IFN α in patients receiving long-term nucleot(s)ide analog treatment, which may lead to an increase in HBeAg and HBsAg loss. In summary, tailored Peg-IFN α therapeutic strategies based on predictors extended the landscape for CHB treatment.

Factors and virological significance of hepatitis B virus pregenomic RNA status after 5 years of antiviral therapy

OBJECTIVES

To investigate the factors and virological significance of serum hepatitis B virus (HBV) pregenomic RNA (pgRNA) status after long-term antiviral therapy with nucleos(t)ide analogues (NAs) in patients with chronic hepatitis B (CHB).

METHODS

In total, 51 treatment-naïve patients with CHB were included in the study. Clinical data were collected at baseline, during 5 years and at year 10 of NA treatment. Serum HBV pgRNA status of 51 patients was determined at year 5.

RESULTS

At year 5, 45% of the patients remained positive for HBV pgRNA. There were significant differences in baseline hepatitis B e antigen (HBeAg) status, HBV DNA load and hepatitis B surface antigen (HBsAg) levels between patients testing positive and negative for HBV pgRNA at year 5. Serum HBV pgRNA status and serum HBV DNA load were correlated after 5 years of NA treatment (r = 0.347, P = 0.013). Being HBV pgRNA positive at year 5 was an independent risk factor for sustainedly undetectable HBV DNA after 10 years of NA treatment (odds ratio 13.638, 95% confidence interval 1.32-140.81; P = 0.028). Furthermore, HBV pgRNA status at year 5 was associated with HBV DNA re-appearance at year 10 (P = 0.009).

CONCLUSIONS

HBV pgRNA status at year 5 can reveal HBV covalently closed circular DNA (cccDNA) activity, and HBV pgRNA positivity after long-term antiviral therapy may indicate higher transcriptional activity of HBV cccDNA. Long-term dynamic monitoring of HBV pgRNA should be considered.

Hepatitis B virus RNA decline without concomitant viral antigen decrease is associated with a low probability of sustained response and hepatitis B surface antigen loss

BACKGROUND

Serum hepatitis B virus (HBV) RNA may reflect intrahepatic HBV replication. Novel anti-viral drugs have shown potent HBV RNA decline without concomitant hepatitis B surface antigen (HBsAg) decrease. How this relates to off-treatment response is yet unclear.

AIM

To study the degree of on-treatment viral antigen decline among patients with pronounced HBV RNA decrease in relation to off-treatment sustained response and HBsAg loss.

METHODS

HBV RNA, HBsAg and hepatitis B core-related antigen (HBcrAg) were quantified in patients with chronic hepatitis B who participated in two randomised controlled trials of peginterferon-based therapy. Sustained response (HBV DNA <2000 IU/mL) and/or HBsAg loss were assessed in patients with and without on-treatment HBV RNA response (either >2 log HBV RNA decline or >1 log decline resulting in an undetectable value at on-treatment week 24), stratified by concomitant HBsAg decline (<0.5/0.5-1/>1 log).

RESULTS

We enrolled 279 patients; 176 were hepatitis B e antigen (HBeAg)-positive, and 103 were HBeAg-negative. Sustained response was achieved in 20.4% of patients. At on-treatment week 24, HBV RNA response was associated with higher sustained response rates (27.4% vs 13.0% in non-responders, P =  0.004). However, among patients with an HBV RNA response (n = 135), 56.4% did not experience >0.5 log HBsAg decline. Among HBV RNA responders, sustained response was achieved in 47.6% of those with >1 log HBsAg decline (n = 20/42), vs 16.0% with <0.5 log decline (n = 12/75, P = 0.001). Similar results were obtained with HBcrAg and when response was defined as HBsAg loss.

CONCLUSIONS

In this cohort, many patients with HBV RNA response during peginterferon-based treatment did not experience HBsAg and/or HBcrAg decline. The absence of concomitant decline in these viral antigens was associated with low rates of treatment response and HBsAg loss. Future trials should therefore consider kinetics of combined biomarkers to assess anti-viral efficacy. Trial registration, ClinicalTrials.gov: NCT00114361, NCT00146705.

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.

Serum Hepatitis B Virus RNA Levels Predict HBeAg Seroconversion and Virological Response in Chronic Hepatitis B Patients with High Viral Load Treated with Nucleos(t)ide Analog

Background and Aim

Hepatitis B virus (HBV) RNA has attracted increasing attention as a novel serum marker for intrahepatic HBV replication. However, the predictive value of the serum level of HBV RNA for hepatitis B e-antigen (HBeAg) seroconversion and viral response among patients with a high viral load (HVL) is unclear. We evaluated the role of the serum level of HBV RNA as a predictor of treatment response in chronic HBV (CHB) patients with an HVL.

Patients and Methods

The study cohort was 66 HBeAg-positive CHB patients with an HVL (serum HBV DNA >1.9×10⁶ IU/mL) at baseline from our previous prospective cohort study treated with lamivudine (LAM) and adefovir dipivoxil(ADV) (N=31) or entecavir alone (N=35) for ≤96 weeks. The serum HBV RNA level was quantified by TaqMan^® probe-based reverse transcription real-time quantitative polymerase chain reaction at four time points.

Results

The baseline serum HBV RNA level (in log₁₀ copies/mL) in patients treated with LAM+ADV and ETV monotherapy was 8.97±1.22 and 9.15±0.92, respectively. After nucleos(t)ide analog (NA) therapy, the serum HBV RNA level decreased steadily in all patients (week 0 vs week 12, p<0.001; week 12 vs week 24, p=0.010; week 24 vs week 48, p<0.001). Fifty-three (80.3%) patients achieved a virologic response (VR), and 12 (18.2%) achieved HBeAg seroconversion after 96 weeks. Multivariate analyses revealed that the serum HBV RNA level at week 12 could predict HBeAg seroconversion (OR 3.560, 95% CI: 1.39–9.110, p=0.008) and VR (1.908, 1.115–3.265, 0.018) at 96 weeks. Analyses of receiver operating characteristic curves indicated that the serum HBV RNA level 12 weeks after NA treatment had predictive value for HBeAg seroconversion (AUC=0.847, p<0.001) and VR (AUC=0.736, p=0.011).

Conclusion

The serum level of HBV RNA at 12 weeks could predict HBeAg seroconversion and a VR during NA treatment in CHB patients with an HVL.