Clinical relevance of the study of hepatitis B virus covalently closed circular DNA

Hepatitis B surface antigen glycan isomer is a predictor of the development of hepatocellular carcinoma during nucleoside/nucleotide analog therapy

AIM

A recombinant monoclonal antibody against the hepatitis B surface antigen glycan isomer (HBsAgGi) was newly developed using the O-glycosylated PreS2 peptide in M-HBsAg of hepatitis B virus (HBV) genotype C. However, the association between HBsAgGi and the development of hepatocellular carcinoma (HCC) during nucleoside/nucleotide analog (NA) therapy remains unknown.

METHODS

A total of 112 HBV genotype C-infected patients who were treated with NA were included in this study. We assessed the association between HBV markers, including HBsAgGi and other conventional markers, and the development of HCC during NA therapy.

RESULTS

Ten patients developed HCC during the follow-up period. Of the HBV markers, HBsAg (≤3.53 log IU/mL; p = 0.047), HBsAgGi/HBsAg ratio (≥1.10; p = 0.035), and HBV DNA (≤6.3 log copies/mL; p = 0.012) at baseline and HBsAg (≤3.19 log IU/mL; p = 0.033) and HBsAgGi/HBsAg ratio (≥1.09; p = 0.003) at 48 weeks after NA therapy were significantly associated with the development of HCC according to the log rank test. In contrast, no significant association was observed between HBsAgGi and the development of HCC. Multivariate analysis revealed that a platelet count at baseline ≤88 × 103/mm3 (p = 0.026; hazard ratio [HR], 10.577) and an HBsAgGi/HBsAg ratio at 48 weeks after NA therapy ≥1.09 (p = 0.040; HR, 10.099) were independently and significantly associated with the development of HCC.

CONCLUSIONS

Our findings suggest that a combination of on-treatment HBsAgGi and HBsAg predicts the development of HCC during NA therapy.

Effect of S-region mutations on HBsAg in HBsAg-negative HBV-infected patients

BACKGROUND

Occult HBV infection (OBI) is a special form of hepatitis B virus (HBV) infection that may cause Liver cirrhosis and hepatocellular carcinoma, causing significant harm to patients. Given the insidious nature of OBI, it is usually not easy to be detected. Most of the samples currently studied are concentrated on blood donors, however, patients in this special state have not been fully studied. This project aimed to study the effect of HBV S region mutations on HBsAg in patients with clinical OBI.

METHODS

Collect 107 HBsAg-/HBV DNA + blood samples from Beijing Youan Hospital, Capital Medical University from August 2022 to April 2023. Next, the successfully extracted and amplified HBV DNA S regions were sequenced. Construct mutant plasmids to verify the cell function of the high-frequency mutation sites and explore the possible molecular mechanism.

RESULTS

Sixty-eight HBsAg-negative samples were sequenced, revealing high-frequency amino acid substitution sites in the HBV S protein, including immune escape mutations (i.e., sY100C、sK122R、sI126T、sT131P、and sS114T) and TMD (Transmembrane domain) region substitutions (i.e., sT5A、sG10D、sF20S、and sS3N). We constructed a portion of the mutant plasmids and found that sT5A, sF20S, sG10D, sS3N, sI68T, and sI126T single point mutations or combined mutations may decrease HBsAg expression or change the antigenicity of HBsAg leading to detection failure.

CONCLUSIONS

HBsAg-negative patients may show various mutations and amino acid replacement sites at high frequency in the HBV S-region, and these mutations may lead to undetectable Hepatitis B surface antigen (HBsAg), HBsAg antigenic changes or secretion inhibition.

Post-operative recurrence of liver cancer according to antiviral therapy for detectable hepatitis B viremia: A nationwide study

BACKGROUND

High postoperative recurrence of hepatitis B virus (HBV)-infected hepatocellular carcinoma (HCC) remains a significant challenge. Here, we aimed to compare the postoperative HCC recurrence between patients with AVT for detectable serum HBV-DNA vs. those without.

METHODS

Data of patients undergoing curative resection of HBV-infected HCC as an initial therapy from 2015 to 2017 were obtained from the National Health Insurance Service database in South Korea. AVT was initiated when serum HBV-DNA was detectable. The primary outcome was HCC recurrence. The cumulative risk of HCC recurrence between AVT users and non-users was estimated using the Kaplan-Meier method.

RESULTS

During follow-up (median 2.7 years) with 3034 patients, 25.7% and 23.6% of AVT users and non-users experienced HCC recurrence, respectively. The 1-, 2-, and 3-year cumulative recurrence rates were similar (p = 0.57): 15.6%, 23.3%, and 26.4% in AVT users versus 15.3%, 22.0%, and 24.9% in non-users, respectively. After adjusting for covariates, multivariable Cox regression analysis showed comparable outcomes between the two groups with adjusted hazard ratios (aHR 1.08, 95% confidence interval [CI] 0.89-1.31; p = 0.439). Similar outcomes between the two groups were reproduced after stratification of liver cirrhosis. Inverse probability treatment weighting analysis also showed comparable outcomes between the two groups in the subgroups with liver cirrhosis (aHR 1.01, 95% CI 0.80-1.29; p = 0.92) and non-cirrhosis (aHR 1.08, 95% CI 0.87-1.34; p = 0.472).

CONCLUSIONS

Initiating AVT based on detectable serum HBV-DNA provided the similar risk of postoperative HCC recurrence in HBV-infected HCC patients with and without detectable serum HBV-DNA.

Role of S Protein Transmembrane Domain Mutations in the Development of Occult Hepatitis B Virus Infection

Occult HBV infection (OBI) is a special infection status during Hepatitis B virus (HBV) infection. The underlying mechanism of its occurrence remains unclear. This study conducted sequencing analysis on 104 OBI plasma samples and 524 HBsAg positive samples from 29 blood centres, and searched for high-frequency mutations in transmembrane domain (TMD) of S protein in the OBI population. Plasmids with TMD high-frequency mutations were constructed, in vivo and in vitro functional experiments were performed to investigate possible molecular mechanisms of OBI occurrence. We found 22 high-frequency TMD mutations in genotype B OBI strains. Among them, five mutations can lead to impairment of HBsAg secretion; seven mutations had accumulated intracellular HBsAg while extracellular HBsAg didn’t decrease compared to wildtype. This study chose C85R from TMD2, F220C, and F220Y from TMD4 for further exploration. Protein structure predication showed these three mutant HBsAg displayed changed hydrophilic properties and tended to accumulate in the phospholipid bilayer of cell membrane. Mutant HBsAg’s secretion disorder may induce OBI. On the other hand, V168A + V177A from TMD3 expressed increased HBsAg both in intracellular and extracellular levels. This mutation had most unstable natural conformation and may be inclined to transition into V177A or V168A + S174N + V177A. These three mutations were more prone to mixed infection, presenting a state of coexistence, thus approaching the impaired secretion pattern of OBI. This study demonstrated TMD mutations could contribute to the occurrence of OBI and provided a theoretical basis for OBI study and the functional cure of chronic hepatitis B virus infection.

Analysis of antiviral efficacy after switching from brand to generic entecavir in patients with treatment-naïve chronic hepatitis B

Background/Aims

Entecavir (ETV) can suppress chronic hepatitis B (CHB) virus replication as a standard of treatment drugs. For the treatment of CHB, affordable generic drugs may be more widely used in developing and undeveloped countries. However, there is little real-world data regarding the clinical efficacy of switching from entecavir-brand-name drugs (ETV-Brand) to entecavir generic drugs (ETV-Generic) with 0.5 mg once daily. The aim of the study was to evaluate the antiviral activity and safety of ETV-Generic in comparison to ETV-Brand in CHB-patients.

Methods

In this single-center, retrospective, 175 treatment-naïve—CHB-patients were assigned to receive 0.5 mg of ETV-Brand per day for a least 2 years and then switched to ETV-Generic for 6 months for analysis. The primary efficacy endpoint was a sustained virological response in comparison of the rate of undetectable serum Hepatitis B deoxyribonucleic acid (HBV DNA) as the sustained virologic response at baseline and 6 months after switching. Secondary efficacy endpoints were the comparison of the alanine aminotransferase (ALT) levels between before and after switching and ALT normalization. Renal safety consideration was reported on changing the estimated glomerular filtration rate.

Results

From baseline to 6 months, the rate of undetectable HBV DNA and ALT levels remained stable as compared ETV-Brand period with ETV-Generic for 6 months. The rate of undetectable HBV DNA were 81.1%in ETV-Brand versus 88.0%in ETV-Generic (p = 0.05 CI 0.1–13.5%). ALT levels were 27.2 IU/L (CI 24.8–29.6 IU/L) in ETV-Brand versus 26.2 IU/L (CI 24.0–28.4 IU/L) in ETV-Generic (p = 0.55). Both endpoints were not significantly different between ETV-Brand and ETV-Generic treatments. Kidney function did not significantly differ from ETV-Brand (80.8, interquartile range [IQR]: 66.6–95.3 mL/min/1.73 m²) to ETV-Generic treatment period (80.3, IQR: 65.6–93.5 mL/min/1.73 m²).

Conclusion

In treatment-naïve CHB-patients, the efficacy and safety profiles of switching from ETV-Brand to ETV-Generic showed no difference. Concluding the ETV-Generic comes to exciting virologic responses and rare adverse events.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02317-7.

Challenges in the discontinuation of chronic hepatitis B antiviral agents

Long-term antiviral treatment of chronic hepatitis B patients has been proven to be beneficial in reducing liver-related complications. However, lengthy periods of daily administration of medication have some inevitable drawbacks, including decreased medication adherence, increased cost of treatment, and possible long-term side effects. Currently, discontinuation of antiviral agent has become the strategy of interest to many hepatologists, as it might alleviate the aforementioned drawbacks and increase the probability of achieving functional cure. This review focuses on the current evidence of the outcomes following stopping antiviral treatment and the factors associated with subsequent hepatitis B virus relapse, hepatitis B surface antigen clearance, and unmet needs.

Hepatitis B surface antigen, core-related antigen and HBV RNA: Predicting clinical relapse after NA therapy discontinuation

BACKGROUND & AIMS

The safe discontinuation of nucleos(t)ide analogue therapy remains challenging in chronic hepatitis B. We investigated the potential role of quantitative hepatitis B surface antigen, hepatitis B core-related antigen and hepatitis B virus RNA at the end of treatment in predicting off-therapy relapse.

METHODS

Patients who fulfilled the stopping criteria of the Asian Pacific Association for the Study of the Liver guideline were enrolled. Virological relapse was defined as hepatitis B virus DNA level greater than 2000 IU/mL, and clinical relapse was defined as virological relapse plus alanine aminotransferase level of more than twice the upper limit of normal.

RESULTS

Ninety-two patients participated. The combination of end-of-treatment hepatitis B core-related antigen and hepatitis B virus RNA levels was most predictive of clinical relapse. Multivariate analysis revealed that end-of-treatment hepatitis B core-related antigen and hepatitis B virus RNA were independently associated with clinical relapse. During follow-up, no patients with undetectable hepatitis B core-related antigen (<3.0 log₁₀ U/mL) and hepatitis B virusRNA (<2.0 log₁₀ copies/mL) at end of treatment developed clinical relapse, in comparison with 22.9% and 62.5% patients with detectable levels of one or both biomarkers respectively. End-of-treatment quantitative hepatitis B surface antigen was linked to a likelihood of hepatitis B surface antigen clearance.

CONCLUSIONS

The combined hepatitis B core-related antigen and hepatitis B virus RNA assays at end of treatment were highly predictive of subsequent clinical relapse. These novel biomarkers could potentially be used to identify patients who could safely discontinue nucleos(t)ide analogue therapy.

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.

Potential Drug Targets Against Hepatitis B Virus Based on Both Virus and Host Factors

BACKGROUND

Hepatitis B is a very harmful and epidemic disease caused by hepatitis B virus (HBV). Although an effective anti-HBV vaccine is available, chronic infection poses still a huge health burden in the whole world. The present anti-HBV drugs including nucleoside analogues and interferonalpha have their limitations without exception. There is no effective drug and therapeutic method that can really and truly cure hepatitis B so far. The variability of HBV genome results in that a significant number of patients develop drug resistance during the long-term use of anti-HBV drugs. Hence, it is urgently needed to discover novel targets and develop new drugs against hepatitis B.

OBJECTIVE

The review aims to provide the theory support for designing of the anti-HBV innovative drugs by offering a summary of the current situation of antiviral potential targets.

RESULTS AND CONCLUSION

Since HBV is obligate intracellular parasite, and as such it depends on host cellular components and functions to replicate itself. The targeting both virus and host might be a novel therapeutic option for hepatitis B. Accordingly, we analyse the advances in the study of the potential drug targets for anti-HBV infection, focusing on targeting virus genome, on targeting host cellular functions and on targeting virus-host proteins interactions, respectively. Meanwhile, the immune targets against chronic hepatitis B are also emphasized. In short, the review provides a summary of antiviral therapeutic strategies to target virus factors, host factors and immune factors for future designing of the innovative drug against HBV infection.

Effect of HBV-HDV co-infection on HBV-HCC co-recurrence in patients undergoing living donor liver transplantation

PURPOSE

To evaluate the effect of hepatitis D virus (HDV) on hepatitis B virus-hepatocellular carcinoma (HBV-HCC) co-recurrence in patients undergoing living donor liver transplantation (LDLT) for HBV alone or HBV-HDV coinfection.

METHODS

Between 2002 and 2019, 254 HBV-HCC patients underwent LDLT. The patients were divided into two groups after the application of the exclusion criteria: HBV-HCC (Group B; n = 163) and HBV-HDV-HCC (Group D; n = 31). First, the B and D groups were compared in terms of demographic and clinical parameters. Second, patients with (n = 16) and without (n = 178) post-transplant HBV-HCC co-recurrences were grouped and compared in terms of the same parameters.

RESULTS

Although the risk of HBV-HCC co-recurrence in group D was 4.99-fold higher than in group B, the risk of HBV recurrence alone in group D was 12.5-fold lower than in group B. The AFP (OR = 4.4), Milan criteria (beyond; OR = 18.8), and HDV (OR = 8.1) were identified as the independent risk factors affecting post-transplant HBV-HCC co-recurrence. The Milan criteria (OR = 2.1) and HBV-HCC co-recurrence (OR = 10.9) were identified as the risk factors affecting post-transplant mortality. HBV-HCC co-recurrence developed in 26.5% of patients in Group B and 100% in Group D (OR = 40; p = 0.001). HCC recurrence alone developed in 10% of patients without HBV recurrence in group B and 0% of patients without HBV recurrence in group D (OR = 5.7).

CONCLUSION

This study showed that the risk of HBV recurrence alone was reduced by 12.5-fold in the presence of HDV; however, the HCC recurrence occurred in all patients with HDV when HBV recurrence developed.

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.

Hepatitis B reactivation in patients with hepatitis B core antibody positive and surface antigen negative on immunosuppressants

Hepatitis B viral (HBV) reactivation in the immunosuppressed is a significant problem even in patients who have achieved serological clearance due to the persistence of HBV as cccDNA. HBV reactivation will continue to pose a significant healthcare burden given the high prevalence of HBV and increasing use of immunosuppressants. Screening of hepatitis B surface antigen, antibody to Hepatitis B core antigen antibody and HBV DNA levels should be done routinely in all patients planned for significant immunosuppressant use. We aimed to examine the factors affecting reactivation risk. This depended on HBV disease status, the underlying disease requiring immunosuppression, and the specific immunosuppressive regime. While antiviral prophylaxis can prevent reactivation, it increases cost and still has risk of delayed reactivation after stopping antivirals and close follow-up and on-demand treatment is a good alternative for patients at risk of reactivation.

Proposed model for the prediction of intrahepatic covalently closed circular DNA level in patients with chronic hepatitis B

AIM

We sought to create a prediction model for intrahepatic covalently closed circular DNA (IH-cccDNA) level in chronic hepatitis B (CHB) patients and to validate the model's predictive accuracy.

METHODS

Patients who did not receive previous nucleoside analogue (NA) therapy were assigned to the training cohort (n = 57), and those who received previous NA therapy were assigned to the validation cohort (n = 69). Factors linked to IH-cccDNA levels in the training cohort were analyzed and a formula to predict IH-cccDNA levels was constructed. Next, the reproducibility of that formula was assessed.

RESULTS

In the multivariate analysis for the prediction of IH-cccDNA level in the training cohort, fasting blood sugar (FBS) (P = 0.0227), hepatitis B e antigen (HBeAg) (P = 0.0067) and log₁₀ (HB surface antigen [HBsAg]) (P = 0.0497) were significant, whereas HB core-related antigen (HBcrAg) tended to be significant (P = 0.0562). The formula was constructed and named the FBS-cres score based on the variables used (FBS, HBcrAg, HBeAg, and HBsAg). The FBS-cres score was calculated as: 3.1686 - (0.0148 × FBS) + (0.1982 × HBcrAg) + (0.0008168 × HBeAg) + (0.1761 × log₁₀ (HBsAg)). In the training cohort, a significant correlation was noted between HBcrAg and IH-cccDNA levels (P < 0.0001, r = 0.67), whereas the FBS-cres score was more closely correlated to IH-cccDNA level (P < 0.0001, r = 0.81). In the validation cohort, significant correlation was found between HBcrAg and IH-cccDNA levels (P = 0.0012, r = 0.38), whereas the FBS-cres score was more closely linked to IH-cccDNA levels (P < 0.0001, r = 0.51). Similar tendencies were observed in all subgroup analyses.

CONCLUSION

Our proposed model for the prediction of IH-cccDNA level could be helpful in CHB patients.

Screening for inhibitor of episomal DNA identified dicumarol as a hepatitis B virus inhibitor

Currently, there is no available therapy to eradicate hepatitis B virus (HBV) in chronically infected individuals. This is due to the difficulty in eliminating viral covalently closed circular (ccc) DNA, which is central to the gene expression and replication of HBV. We developed an assay system for nuclear circular DNA using an integration-deficient lentiviral vector. This vector produced non-integrated circular DNA in nuclei of infected cells. We engineered this vector to encode firefly luciferase to monitor the lentiviral episome DNA. We screened 3,840 chemicals by this assay for luciferase-reducing activity and identified dicumarol, which is known to have anticoagulation activity. We confirmed that dicumarol reduced lentiviral episome DNA. Furthermore, dicumarol inhibited HBV replication in cell culture using NTCP-expressing HepG2 and primary human hepatocytes. Dicumarol reduced intracellular HBV RNA, DNA, supernatant HBV antigens and DNA. We also found that dicumarol reduced the cccDNA level in HBV infected cells, but did not affect HBV adsorption/entry. This is a novel assay system for screening inhibitors targeting nuclear cccDNA and is useful for finding new antiviral substances for HBV.

New and Old Biomarkers for Diagnosis and Management of Chronic Hepatitis B Virus Infection

Tests to detect the presence and activity of hepatitis B virus (HBV) are the cornerstones of diagnosis and management. Assays that detect or measure serum levels of HB surface antigen, HB surface antibody, and HB core antibody are used to identify patients with exposure to HBV, whereas other tests provide information on the level of virus replication, presence of specific variants, and presence of virus reservoirs. Newer diagnostic tests, used only in research settings so far, aim to quantify levels of intrahepatic HBV replication. Other tests have been developed to detect HBV infection in resource-limited settings. We review point-of-care tests (essential in global screening efforts), standard diagnostic tests used in routine clinical management, and newer tests that might be used in clinical trials of agents designed to cure HBV infection.

Management of Hepatitis B Virus Infection: 2018 Guidelines from the Canadian Association for the Study of Liver Disease and Association of Medical Microbiology and Infectious Disease Canada

Hepatitis B virus (HBV) infection is an important public health problem in Canada. In keeping with evolving evidence and understanding of HBV pathogenesis, the Canadian Association for the Study of Liver Disease periodically publishes HBV management guidelines. The goals of the 2018 guidelines are to (1) highlight the public health impact of HBV infection in Canada and the need to improve diagnosis and linkage to care, (2) recommend current best-practice guidelines for treatment of HBV, (3) summarize the key HBV laboratory diagnostic tests, and (4) review evidence on HBV management in special patient populations and include more detail on management of HBV in pediatric populations. An overview of novel HBV tests and therapies for HBV in development is provided to highlight the recent advances in HBV clinical research. The aim and scope of these guidelines are to serve as an up-to-date, comprehensive resource for Canadian health care providers in the management of HBV infection.

Hepatitis B Virus Serum DNA andRNA Levels in Nucleos(t)ide Analog-Treated or Untreated Patients During Chronic and Acute Infection

Treatment of chronic hepatitis B (CHB) patients with nucleos(t)ide analogs (NAs) suppresses hepatitis B virus (HBV) DNA synthesis but does not affect synthesis of HBV pregenomic RNA (pgRNA). Hepatitis B virus pgRNA is detectable in the serum during NA treatment and has been proposed as a marker of HBV covalently closed circular DNA activity within the infected hepatocyte. We developed an automated assay for the quantification of serum HBV pgRNA using a dual-target real-time quantitative PCR approach on the Abbott m2000sp/rt system. We demonstrate accurate detection and quantification of serum HBV RNA. Hepatitis B virus DNA was quantified using the Abbott RealTime HBV viral load assay. We further compared serum nucleic acid levels and kinetics in HBV-positive populations. Samples included on-therapy CHB samples (n = 16), samples (n = 89) from 10 treatment naïve CHB subjects receiving 12 weeks of NA treatment with 8-week follow-up, hepatitis B surface antigen-positive blood donor samples (n = 102), and three seroconversion series from plasmapheresis donors (n = 79 samples). Conclusion: During NA treatment of CHB subjects, we observed low correlation of HBV DNA to pgRNA levels; pgRNA concentration was generally higher than HBV DNA concentrations. In contrast, when NA treatment was absent we observed serum pgRNA at concentrations that correlated to HBV DNA and were approximately 2 log lower than HBV DNA. Importantly, we observe this trend in untreated subject samples from both chronic infections and throughout seroconversion during acute infection. Results demonstrate that the presence of pgRNA in serum is part of the HBV lifecycle; constant relative detection of pgRNA and HBV DNA in the serum is suggestive of a linked mechanism for egress for HBV DNA or pgRNA containing virions.

Understanding the hepatitis B core positive liver donor

The increasing number of patients on the Singapore national liver transplant waiting list and the lack of donor livers have necessitated a review of the limited use of marginal donor liver grafts. Some grafts are of good quality but are considered marginal due to positive donor antibody to hepatitis B virus core protein serology, and negative hepatitis B surface antigen (HBsAg) and hepatitis B DNA. The fear is of viral reactivation during periods of intense immunosuppression. This is made possible by the ability of the hepatitis B virion to reside in a dormant state within the hepatocyte nucleus despite HBsAg clearance, i.e. the occult hepatitis B infection (OBI). In truth, appropriate selection of recipients and effective post-transplantation immunoprophylaxis significantly reduce the risk of hepatitis B viral reactivation. This article explains the confusion surrounding OBI and reviews current recommendations on how to manage such donor liver grafts.

Quantitation of HBV cccDNA in anti-HBc-positive liver donors by droplet digital PCR: A new tool to detect occult infection

BACKGROUND & AIMS

The accurate diagnosis of occult hepatitis B virus (HBV) infection (OBI) requires the demonstration of HBV DNA in liver biopsies of hepatitis B surface antigen-negative individuals. However, in clinical practice a latent OBI is deduced by the finding of the antibody to the hepatitis B core antigen (anti-HBc). We investigated the true prevalence of OBI and the molecular features of intrahepatic HBV in anti-HBc-positive individuals.

METHODS

The livers of 100 transplant donors (median age 68.2 years; 64 males, 36 females) positive for anti-HBc at standard serologic testing, were examined for total HBV DNA by nested-PCR and for the HBV covalently closed circular DNA (HBV cccDNA) with an in-house droplet digital PCR assay (ddPCR) (Linearity: R² = 0.9998; lower limit of quantitation and detection of 2.4 and 0.8 copies/10⁵ cells, respectively).

RESULTS

A total of 52% (52/100) of the individuals studied were found to have OBI. cccDNA was found in 52% (27/52) of the OBI-positive, with a median 13 copies/10⁵ cells (95% CI 5-25). Using an assay specific for anti-HBc of IgG class, the median antibody level was significantly higher in HBV cccDNA-positive than negative donors (17.0 [7.0-39.2] vs. 5.7 [3.6-9.7] cut-off index [COI], respectively, p = 0.007). By multivariate analysis, an anti-HBc IgG value above 4.4 COI was associated with the finding of intrahepatic HBV cccDNA (odds ratio 8.516, p = 0.009); a lower value ruled out its presence with a negative predictive value of 94.6%.

CONCLUSIONS

With a new in-house ddPCR-based method, intrahepatic HBV cccDNA was detectable in quantifiable levels in about half of the OBI cases examined. The titer of anti-HBc IgG may be a useful surrogate to predict the risk of OBI reactivation in immunosuppressed patients.

LAY SUMMARY

The covalently closed circular DNA (cccDNA) form of the hepatitis B virus (HBV) sustains the persistence of the virus even decades after resolution of the symptomatic infection (occult HBV infection). In the present study we developed a highly sensitive method based on droplet digital PCR technology for the detection and quantitation of HBV cccDNA in the liver of individuals with occult HBV infection. We observed that the amount of HBV cccDNA may be inferred from the titer in serum of the IgG class antibody to the hepatitis B core antigen. The quantitation of this antibody may represent a surrogate to determine which patients are at the highest risk of HBV reactivation following immunosuppressive therapies.

Liver sampling: a vital window into HBV pathogenesis on the path to functional cure

In order to optimally refine the multiple emerging drug targets for hepatitis B virus (HBV), it is vital to evaluate virological and immunological changes at the site of infection. Traditionally liver biopsy has been the mainstay of HBV disease assessment, but with the emergence of non-invasive markers of liver fibrosis, there has been a move away from tissue sampling. Here we argue that liver biopsy remains an important tool, not only for the clinical assessment of HBV but also for research progress and evaluation of novel agents. The importance of liver sampling has been underscored by recent findings of specialised subsets of tissue-resident immune subsets capable of efficient pathogen surveillance, compartmentalised in the liver and not sampled in the blood. Importantly, the assessment of virological parameters, such as cccDNA quantitation, also requires access to liver tissue. We discuss strategies to maximise information obtained from the site of infection and disease pathology. Fine needle aspirates of the liver may allow longitudinal sampling of the local virus/host landscape. The careful utilisation of liver tissue and aspirates in conjunction with blood will provide critical information in the assessment of new therapeutics for the functional cure of HBV.

Cumulative incidence and risk factors for the development of hepatocellular carcinoma in patients with chronic hepatitis B who achieved sustained disappearance of viremia by nucleos(t)ide analog treatment

AIM

Nucleos(t)ide analog (NA) therapy has been reported to reduce the risk of hepatocellular carcinoma (HCC). However, some patients who achieve hepatitis B virus (HBV)-DNA disappearance from serum by NA develop HCC. In this study, we investigated the cumulative incidence and risk factors for HCC in patients with chronic hepatitis B (CHB) who achieved sustained disappearance of viremia by NA treatment.

METHODS

A total of 133 CHB patients (median age, 51 years; 79 men [59%]; 28 with cirrhosis [21%]) who received NA therapy and achieved HBV-DNA disappearance from serum were analyzed retrospectively. We evaluated the cumulative incidence of HCC and risk factors associated with HCC based on data collected at the time of HBV-DNA disappearance.

RESULTS

Thirteen patients developed HCC during the follow-up period. The 1-, 3-, and 5-year cumulative incidence of HCC was 0.0%, 7.8%, and 11.1%, respectively. In multivariate analysis, advanced age (hazard ratio [HR], 4.601; 95% confidence interval [CI], 1.220-17.351; P = 0.024), liver cirrhosis (HR, 5.563; 95% CI, 1.438-21.519; P = 0.013), and higher HBV core-related antigen (HBcrAg) levels (HR, 13.532; 95% CI, 1.683-108.815; P = 0.014) at the time of HBV-DNA disappearance were significantly associated with the development of HCC.

CONCLUSION

Our findings indicate the importance of continuous HCC surveillance especially in patients with advanced age, cirrhosis, and/or higher serum levels of HBcrAg, even if they achieve HBV-DNA disappearance.

Prophylactic effect of lamivudine on chemotherapy-induced hepatitis B virus reactivation in patients with solid tumour: A meta-analysis

Hepatitis B virus (HBV) reactivation is a remarkable risk during the chemotherapy for solid tumour patients. Nucleos(t)ide analogues (NAs) are recommended as prophylaxis for the reactivation of HBV infection in some cancer patients prior to systemic chemotherapy. Therefore, we performed a meta-analysis aiming to determine the efficacy of prophylactic lamivudine on prevention of HBV reactivation and its related negative outcomes among solid tumour patients with chronic HBV infection receiving systemic chemotherapy. The primary outcome was HBV reactivation, and the secondary outcomes were HBV-related hepatitis, chemotherapy disruption, mortality and tyrosine-methio-nine-aspartate-aspartate (YMDD) mutations. Twelve original researches involving 1,101 patients were analysed in this study. The relative risk of HBV reactivation in patients with lamivudine prophylaxis was significantly lower than that without prophylaxis (RR = 0.17, 95% CL: 0.10-0.29, p < .00001). Lamivudine prophylaxis reduced the relative risk of hepatitis (p < .00001), chemotherapy disruptions (p = .01) and mortality (p = .08) due to HBV reactivation. Lamivudine prophylaxis is effective in reducing HBV reactivation and its related negative outcomes, such as hepatitis and chemotherapy disruption and mortality among chemotherapeutic solid tumour patients with chronic HBV infection. Future studies should lay more emphasis on the early HBV screening, mode of treatment and duration of NAs prophylaxis among solid tumour patients receiving chemotherapy.

Analysis of intrahepatic total HBV DNA, cccDNA and serum HBsAg level in Chronic Hepatitis B patients with undetectable serum HBV DNA during oral antiviral therapy

BACKGROUND

This study aimed to investigate the relationship between intrahepatic cccDNA and serum HBsAg in chronic Hepatitis B (CHB) patients with undetectable serum HBV DNA during antiviral therapy.

METHODS

We investigated HBsAg serum levels and their relationship to intrahepatic total cccDNA and HBV DNA in CHB patients with undetectable serum HBV DNA during oral antiviral therapy. Intrahepatic cccDNA and HBV DNA quantitation were performed in the same needle biopsy material, while serum HBsAg, HBeAg and HBV DNA levels were measured in samples drawn on the day of the liver biopsy.

RESULTS

A total of 90 patients who had a liver biopsy were enrolled, including 80 patients with CHB and 10 patients with liver cirrhosis (LC). All the CHB patients were divided into HBeAg-positive and HBeAg-negative group. By using real-time PCR detection, we found that intrahepatic cccDNA and HBV DNA levels were higher in CHB patients than those in LC patients (Intrahepatic cccDNA: 6.15±1.19 vs. 6.12±0.36, HBV DNA: 7.26±0.49 vs. 5.59±0.45, both P<0.05). Intrahepatic cccDNA level was positively correlated with serum HBsAg in HBeAg-negative (r=0.66, P=0.02) and lower serum HBeAg (≤50S/CO) CHB patients (r=0.47, P=0.03), but not in higher serum HBeAg (>50S/CO) CHB patients (both P>0.05). In HBeAg negative patients, serum HBsAg level was correlated with intrahepatic total HBV DNA level (r=0.52, P=0.006). However, no relationship between HBsAg level and intrahepatic total HBV DNA level was found in HBeAg positive patients (both P>0.05).

CONCLUSIONS

Serum HBsAg can be used to predict intrahepatic cccDNA and HBV DNA level in CHB patients with low serum HBeAg statues, especially in HBeAg negative patients.

Hepatitis B Virus and DNA Damage Response: Interactions and Consequences for the Infection

Hepatitis B virus (HBV) is a major etiologic agent of acute and chronic hepatitis, and end-stage liver disease. Establishment of HBV infection, progression to persistency and pathogenesis are determined by viral and cellular factors, some of which remain still undefined. Key steps of HBV life cycle e.g., transformation of genomic viral DNA into transcriptionally active episomal DNA (cccDNA) or transcription of viral mRNAs from cccDNA, take place in the nucleus of infected cells and strongly depend on enzymatic activities provided by cellular proteins. In this regard, DNA damage response (DDR) pathways and some DDR proteins are being recognized as important factors regulating the infection. On one hand, HBV highjacks specific DDR proteins to successfully complete some of the steps of its life cycle. On the other hand, HBV subverts DDR pathways to presumably create a cellular environment that favours its replication. Direct consequences of these interactions are: HBV DNA integration into host chromosomal DNA, and accumulation of mutations in host chromosomal DNA that could eventually trigger carcinogenic processes, which would explain in part the incidence of hepatocellular carcinoma in chronically infected patients. Unravelling the interactions that HBV establishes with DDR pathways might help identify new molecular targets for therapeutic intervention.

Relationship between serum HBV-RNA levels and intrahepatic viral as well as histologic activity markers in entecavir-treated patients

BACKGROUND & AIMS

In diagnostics, serum hepatitis B virus (HBV)-RNA levels are valuable when the HBV-DNA load in circulation is effectively suppressed by nucleos(t)ide analogue (NUC) therapy. This study aimed to determine the intrahepatic viral replication activity reflected in serum HBV-RNA and whether HBV-RNA contributes to liver histological changes in patients treated with NUC.

METHODS

A cross-sectional set of serum and liver biopsy samples was obtained from patients treated with entecavir, who had undetectable levels of serum HBV-DNA. The correlations between serum HBV-RNA concentration and levels of peripheral and intrahepatic viral replicative forms, as well as histological scores, were analyzed. Quasispecies of serum HBV-RNA and intrahepatic viral replicative forms were examined by deep sequencing. HBV-RNA-positive hepatocytes were visualized by in situ hybridization.

RESULTS

Serum HBV-RNA was detected in 35 of 47 patients (74.47%, 2.33-4.80log10copies/ml). These levels correlated not only with the intrahepatic HBV-RNA level and the ratio of intrahepatic HBV-RNA to covalently closed circular DNA (cccDNA), but also with the histological scores for grading and staging. Regarding quasispecies, serum HBV-RNA was dynamic and more genetically homogenous to simultaneously sampled intrahepatic HBV-RNA than to the cccDNA pool. In situ histology revealed that HBV-RNA-positive hepatocytes were clustered in foci, sporadically distributed across the lobules, and co-localized with hepatitis B surface antigen.

CONCLUSION

Serum HBV-RNA levels reflect intrahepatic viral transcriptional activity and are associated with liver histopathology in patients receiving NUC therapy. Our study sheds light on the nature of HBV-RNA in the pathogenesis of chronic HBV infection and has implications for the management of chronic hepatitis B during NUC therapy.

LAY SUMMARY

Serum HBV-RNA levels are indicative of the intrahepatic transcriptional activity of covalently closed circular DNA and are associated with liver histological changes in patients with chronic B hepatitis who are receiving nucleos(t)ide analogue therapy.

Up-regulation of BRCA1-associated RING Domain 1 Promotes Hepatocellular Carcinoma Progression by Targeting Akt Signaling

The present study was designed to investigate the potential clinical, pathological, prognostic value, role and mechanism of BRCA1-associated RING Domain 1 (BARD1) in Hepatocellular carcinoma (HCC). Quantitative real-time PCR and immunohistochemistry were performed to evaluate the expression of BARD1 mRNA and protein. The expression of BARD1 in the HCC tissue samples was markedly higher than that in the adjacent noncancerous liver tissues. Elevated BARD1 expression was positively correlated with tumor-node-metastasis stage, Barcelona-Clinic Liver Cancer stage, hepatitis B surface antigen, large tumor size, serum alpha-fetoprotein levels, and serum aspartate aminotransferase levels. Univariate and multivariate analyses revealed the BARD1 was an independent predictor for decreased progression-free survival and overall survival in HCC. In vitro experiments demonstrated that knocking down BARD1 significantly inhibited the proliferation, invasion and migration of HCC cells. Moreover, silencing BARD1 inhibit the signaling pathway via decreased the levels of Akt, mTOR, and MMP-9 and inhibited the phosphorylation of Akt (Ser473) and mTOR (Ser2248). Collectively, our findings suggest that BARD1 may be a novel diagnostic and prognostic biomarker of HCC, and up-regulation of BARD1 can contribute to HCC progression by targeting Akt signaling.

Hepatitis B virus covalently closed circular DNA homeostasis is independent of the lymphotoxin pathway during chronic HBV infection

Current treatment options for patients with chronic hepatitis B virus (HBV) infection are not curative as they are not effective in eliminating covalently closed circular DNA (cccDNA). cccDNA is a stable template for HBV transcription in the nucleus of hepatocytes and is thought to be one of the main factors responsible for HBV persistence. Recently, activation of the lymphotoxin beta receptor (LTβR) has been shown to trigger degradation of cccDNA through induction of cytidine deaminases of the APOBEC3 family in HBV cell culture model systems. To assess the presence and relevance of such mechanisms in the liver of chronically HBV-infected patients, we compared intrahepatic cccDNA levels with the expression levels of lymphotoxins and some of their target genes (eg APOBEC deaminases) in liver biopsy tissue. Our results confirm elevated gene expression levels of components of the lymphotoxin pathway including lymphotoxin alpha (LTα), lymphotoxin beta (LTβ), APOBEC3B (A3B) and APOBEC3G (A3G) in the chronically HBV-infected liver compared to uninfected liver. Furthermore, expression levels of the genes of the APOBEC deaminase family were correlated with those of LTα and LTβ gene expression, consistent with lymphotoxin-mediated upregulation of APOBEC gene expression. However, intrahepatic cccDNA and HBV replication levels were not correlated with LTα, LTβ and APOBEC gene expression. In conclusion, these results suggest that although the lymphotoxin pathway is activated in the chronically HBV-infected liver, it has no major impact on HBV cccDNA metabolism in chronic HBV infection.

Hepatitis B virus reactivation in breast cancer patients undergoing chemotherapy: A review and meta-analysis of prophylaxis management

Hepatitis B virus (HBV) reactivation during or after chemotherapy in patients with breast cancer has become a remarkable clinical problem. Prophylactic nucleos(t)ide analogues (NAs) are recommended for patients with breast cancer who are hepatitis B surface antigen (HBsAg) positive before chemotherapy. We performed an up-to-date meta-analysis to compare the efficacy of prophylactic lamivudine use with nonprophylaxis in HBsAg-positive breast cancer patients undergoing chemotherapy. PubMed, the Cochrane Library and China National Knowledge Infrastructure (CNKI) databases were searched for relevant articles until June 2016. Eligible articles comparing the efficacy of prophylactic lamivudine use with nonprophylaxis in HBsAg-positive breast cancer patients undergoing chemotherapy were identified. Eight studies which had enrolled 709 HBsAg-positive breast cancer patients undergoing chemotherapy were analysed. Lamivudine prophylaxis significantly reduced the rates of chemotherapy-associated hepatitis B flares in chronic hepatitis B in breast cancer compared with patients with nonprophylaxis (odds ratio [OR]=0.15, 95% confidence interval [CI]: 0.07-0.35, P<.00001). Chemotherapy disruption rates attributed to HBV reactivation in the prophylaxis groups were significantly lower than the nonprophylaxis groups (OR=0.17, 95% CI: 0.07-0.43, P=.0002). Patients with lamivudine prophylaxis had a higher risk for tyrosine-methionine-aspartate-aspartate (YMDD) motif mutations than patients with nonprophylaxis (OR=6.33, 95% CI: 1.01-39.60, P=.05). Prophylactic antiviral therapy management is necessary for HBsAg-positive breast cancer patients undergoing chemotherapy, in spite of high correlation with lamivudine-resistant HBV variants with YMDD motif mutations.

The Management of Hepatitis B in Liver Transplant Recipients

Liver transplant (LT) is now an established indication for patients with chronic hepatitis B, mainly because of the development and use of hepatitis B immunoglobulin (HBIG) and oral antivirals for prophylaxis. The combination of low-dose HBIG and antivirals has been considered the standard prophylaxis regimen to prevent post-LT recurrence of hepatitis B. The important remaining issues are related to the long-term cost of HBIG and the risk of escape hepatitis B virus (HBV) mutants. Strategies for prevention of HBV after LT are constantly improving. With the availability of new nucleoside/nucleotide analogues, new post-LT strategies also should emerge.