Total and covalently closed circular DNA detection in liver tissue of long-term survivors transplanted for HBV-related cirrhosis

Hepatitis Virus-associated Non-hodgkin Lymphoma: Pathogenesis and Treatment Strategies

Over the last decade, epidemiological studies have discovered a link between hepatitis C virus (HCV) and hepatitis B virus (HBV) infection and non-Hodgkin lymphoma (NHL). The regression of HCV-associated NHL after HCV eradication is the most compelling proof supporting HCV infection's role in lymphoproliferative diseases. HBV infection was found to significantly enhance the incidence of NHL, according to the epidemiological data. The exact mechanism of HCV leading to NHL has not been fully clarified, and there are mainly the following possible mechanisms: (1) Indirect mechanisms: stimulation of B lymphocytes by extracellular HCV and cytokines; (2) Direct mechanisms: oncogenic effects mediated by intracellular HCV proteins; (3) hit-and-run mechanism: permanent genetic B lymphocytes damage by the transitional entry of HCV. The specific role of HBV in the occurrence of NHL is still unclear, and the research on its mechanism is less extensively explored than HCV, and there are mainly the following possible mechanisms: (1) Indirect mechanisms: stimulation of B lymphocytes by extracellular HBV; (2) Direct mechanisms: oncogenic effects mediated by intracellular HBV DNA. In fact, it is reasonable to consider direct-acting antivirals (DAAs) as first-line therapy for indolent HCV-associated B-NHL patients who do not require immediate chemotherapy. Chemotherapy for NHL is affected by HBV infection and replication. At the same time, chemotherapy can also activate HBV replication. Following recent guidelines, all patients with HBsAg positive/HBV DNA≥2,000 IU/mL should be treated for HBV. The data on epidemiology, interventional studies, and molecular mechanisms of HCV and HBV-associated B-NHL are systematically summarized in this review.

Early intrahepatic recurrence of HBV infection in liver transplant recipients despite antiviral prophylaxis

Background & Aims

Prophylaxis with nucleos(t)ide analogues (NUCs) and hepatitis B immunoglobulin (HBIG) has decreased the rate of HBV recurrence after orthotopic liver transplantation (OLT), but the duration of this prophylaxis remains debated. Our aim was to investigate the recurrence of both intrahepatic and serum HBV markers after OLT in patients receiving long-term NUC and HBIG prophylaxis.

Methods

A total of 31 HBV-positive patients benefiting from OLT were prospectively enrolled in five French centres between 2012 and 2015. Tissue samples from the native liver, liver reperfusion biopsy, and 12-month post-OLT (M12) biopsy were collected. Intrahepatic HBV markers were quantified using Droplet Digital PCR. Serum hepatitis B core-related antigen (HBcrAg) and HBsAg were quantified using the Lumipulse platform.

Results

Among the 31 patients, 26 were HBeAg negative and 28 had undetectable serum HBV DNA at OLT. All patients received HBIG and NUC after OLT, and serum HBV DNA was undetectable at M12. Of the 27 available native livers, 26 had detectable total HBV DNA (median, 0.045 copies/cell), 21 were positive for cccDNA (0.001 copies/cell), and 19 were positive for 3.5-kb HBV RNA (0.0004 copies/cell). Among the 14 sequential reperfusion and M12 biopsies, seven were positive for HBV markers on the reperfusion sampling, and six of them were also positive at M12. Of the 27 patients with available serum samples at M12, eight were positive for HBcrAg and five were positive for HBsAg by ultrasensitive quantification, although they were negative by conventional techniques. Overall, among the 17 patients having a matched biopsy and serum sample at M12, only one had undetectable HBV markers in both the liver and serum.

Conclusions

Our results demonstrate a very early detection of viral genome in the graft and intrahepatic viral recurrence despite NUC and HBIG prophylaxis.

Clinical Trials Registration

This study is registered at ClinicalTrials.gov (NCT02602847).

Impact and Implications

In this work, we show that, despite the recommended prophylaxis based on NUC and HBIG, HBV can infect the new liver very rapidly after transplantation. Twelve months after transplantation, the majority of patients had at least one HBV marker detected in either serum or the liver. Therefore, our results demonstrate early intrahepatic viral recurrence despite NUC and HBIG therapy and underline the importance of an optimal patient compliance to the antiviral prophylaxis to prevent viral rebound.

STING signaling activation inhibits HBV replication and attenuates the severity of liver injury and HBV-induced fibrosis

The covalently closed circular DNA (cccDNA) of HBV plays a crucial role in viral persistence and is also a risk factor for developing HBV-induced diseases, including liver fibrosis. Stimulator of interferon genes (STING), a master regulator of DNA-mediated innate immune activation, is a potential therapeutic target for viral infection and virus-related diseases. In this study, agonist-induced STING signaling activation in macrophages was revealed to inhibit cccDNA-mediated transcription and HBV replication via epigenetic modification in hepatocytes. Notably, STING activation could efficiently attenuate the severity of liver injury and fibrosis in a chronic recombinant cccDNA (rcccDNA) mouse model, which is a proven suitable research platform for HBV-induced fibrosis. Mechanistically, STING-activated autophagic flux could suppress macrophage inflammasome activation, leading to the amelioration of liver injury and HBV-induced fibrosis. Overall, the activation of STING signaling could inhibit HBV replication through epigenetic suppression of cccDNA and alleviate HBV-induced liver fibrosis through the suppression of macrophage inflammasome activation by activating autophagic flux in a chronic HBV mouse model. This study suggests that targeting the STING signaling pathway may be an important therapeutic strategy to protect against persistent HBV replication and HBV-induced fibrosis.

2020 position statement and recommendations of the European Liver and Intestine Transplantation Association (ELITA): management of hepatitis B virus-related infection before and after liver transplantation

BACKGROUND

Prophylaxis of HBV recurrence is critical after liver transplantation in HBV patients. Despite new prophylactic schemes, most European LT centres persist on a conservative approach combining hepatitis B immunoglobulin (HBIG) and nucleos(t)ides analogues (NA).

AIM

This setting prompted the European Liver Intestine Transplantation Association (ELITA) to look for a consensus on the prevention of HBV recurrence.

METHODS

Based on a 4-round Delphi process, ELITA investigated 16 research questions and established 50 recommendations.

RESULTS

Prophylaxis should be driven according to 3 simplified risk groups: Low and high virological risk patients, with undetectable and detectable HBV DNA pre-LT, respectively, and special populations (HDV, HCC, poorly adherent patients). In low-risk patients, short-term (4 weeks) combination of third-generation NA+ HBIG, or third generation NA monotherapy can be considered as prophylactic options. In high-risk patients, HBIG can be discontinued once HBV DNA undetectable. Combined therapy for 1 year is advised. HBV-HCC patients should be treated according to their virological risk. In HDV/HBV patients, indefinite dual prophylaxis remains the gold standard. Full withdrawal of HBV prophylaxis following or not HBV vaccination should only be attempted in the setting of clinical trials. Organs from HBsAg+ve donors may be considered after assessment of risks, benefits, and patient consent. They should not be used if HDV is present. In poorly adherent patients, dual long-term prophylaxis is recommended. Budget impact analysis should be taken into account to drive prophylactic regimen.

CONCLUSIONS

These ELITA recommendations should stimulate a more rational and homogeneous approach to HBV prophylaxis across LT programs.

Hepatitis B virus recurrence after liver transplantation: An old tale or a clear and present danger?

Hepatitis B virus (HBV) recurrence after liver transplantation (LT) has been described more than 50 years ago. Similarly, to other clinical conditions, in which impairment of host immune defense favors viral replication, early reports described in details recurrence and reactivation of HBV in liver transplant recipients. The evidence of a possible, severe, clinical evolution of HBV reappearance in a significant percentage of these patients, allowed to consider, for some years, HBV positivity a contraindication for LT. Moving from the old to the new millennium this picture has changed dramatically. Several studies contributed to establish efficient prophylactic protocols for HBV recurrence and with the advent of more potent anti-viral drugs an increased control of infection was achieved in transplanted patients as well as in the general immune-competent HBV population. Success obtained in the last decade led some authors to the conclusion that HBV is now to consider just as a “mere nuisance”. However, with regard to HBV and LT, outstanding issues are still on the table: (1) A standard HBV prophylaxis protocol after transplant has not yet been clearly defined; (2) The evidence of HBV resistant strains to the most potent antiviral agents is claiming for a new generation of drugs; and (3) The possibility of prophylaxis withdrawal in some patients has been demonstrated, but reliable methods for their selection are still lacking. The evolution of LT for HBV is examined in detail in this review together with the description of the strategies adopted to prevent HBV recurrence and their pros and cons.

The role of hepatitis B core-related antigen in predicting hepatitis B virus recurrence after liver transplantation

BACKGROUND

Hepatitis B core-related antigen (HBcrAg) is a viral marker for the development of cirrhosis and hepatocellular carcinoma (HCC) in patients with chronic hepatitis B (CHB). However, the relationship between HBcrAg and HBV recurrence after liver transplantation (LT) is unclear.

AIM

To investigate the correlation of serum HBcrAg level with HBV recurrence post-LT to evaluate the prognostic role of the pre-LT HBcrAg level.

METHODS

This retrospective cohort study enrolled 357 CHB patients who received LT for a median of 36.6 months. Univariate and multivariate analyses and time-dependent receiver operating characteristic (ROC) curves for markers associated with HBV recurrence were analysed.

RESULTS

48 patients (13.4%) had HBV recurrence after LT. HBcrAg, detectable HBV DNA, HCC and HCC recurrence were associated with HBV recurrence. In a multivariate analysis, HBcrAg level was independently associated with HBV recurrence, and the relationship between HBcrAg level and incident HBV recurrence was significant and graded (HR: 3.17 per unit; 95% CI: 1.97-5.11; P for trend < .001). Additionally, HBcrAg level was superior to HBV DNA level in predicting HBV recurrence by time-dependent ROC analysis. Patients with an HBcrAg ≥ 5.0 log U/mL had a significantly higher 5-year cumulative recurrence rate than those with an HBcrAg < 5.0 log U/mL (37.6% vs 6%, P < .001); the adjusted hazard ratio was 5.27 (95% CI 2.47-11.25, P < .001).

CONCLUSION

An elevated serum HBcrAg level was independently associated with the risk of HBV recurrence in patients with CHB after LT.

Hepatitis B Virus cccDNA in Hepatocellular Carcinoma Tissue Increases the Risk of Recurrence After Liver Transplantation

BACKGROUND

High hepatitis B virus (HBV) DNA level is strongly associated with hepatocellular carcinoma (HCC) development in chronic HBV infection. The aim of this study was to investigate the association between intrahepatic HBV DNA titer and post-liver transplantation (LT) prognosis for HBV-related HCC (HBV-HCC) patients.

METHODS

A total of 60 patients with HBV-HCC who underwent LT were retrospectively studied. Using quantitative TaqMan fluorescent real-time polymerase chain reaction assay, HBV total DNA (tDNA) and covalently closed circular DNA (cccDNA) were both quantified in tumor tissue (TT) and adjacent non-tumor tissue (ANTT) from the explanted liver.

RESULTS

The loads of tDNA and cccDNA in ANTT were associated with serum HBV DNA levels. Multivariate analysis showed that the presence of vascular invasion and cccDNA in TT were independent risk factors for tumor recurrence. The group of patients with cccDNA titers ≥31og_l0 copies/μg in TT had significantly higher cumulative recurrence rates than those with <31og_l0 copies/μg group. The cccDNA titers predicted the tumor recurrence with an area under the receiver operating characteristic curve of 0.664.

CONCLUSIONS

Our findings would assist the clinical implementation of a more personalized therapy for tumor recurrence control and improve the prognosis of HBV-HCC patients.

Long-term consequences of stopping HBIG and/or nucleotide analogues in liver transplant recipients administered hepatitis B vaccination to prevent HBV reinfection

BACKGROUND

The long-term administration of nucleotide analogues (NAs) and hepatitis B immune globulin (HBIG) comprises standard prophylaxis for patients with hepatitis B virus (HBV)-related liver diseases to prevent HBV reinfection after liver transplantation (LT). However, prolonging the prophylaxis strategy involves safety issues, such as the development of escape mutations and/or emerging resistant strains, and is also associated with high costs; further, it remains unclear how long prophylactic treatment should be continued.

METHOD

Liver transplantation recipients responding to hepatitis B vaccination due to HBV-related liver diseases were retrospectively analysed after stopping HBIG and/or NAs, administered to prevent HBV reinfection, after long-term follow-up. The safety and effectiveness of the strategy were then evaluated for these responders.

RESULT

Seventy-eight responders were enrolled. All responders discontinued HBIG, among which 36 stopped both HBIG and NAs. During follow-up, four recipients experienced HBV reinfection, which was associated with HBV escape mutations, after the withdrawal of both HBIG and NAs. No death or graft loss occurred in recipients during the follow-up period.

CONCLUSION

A careful withdrawal of HBIG and/or NAs is feasible and safe for responders to hepatitis B vaccination receiving transplants for HBV-related liver diseases.

Management of chronic viral hepatitis in the hematological patient

INTRODUCTION

Infection with HBV and HCV represents a growing challenge in the management of patients with hematological malignancies. Recently, hepatitis E (HEV) was recognized as an endemic infection in developed countries and as an emerging health problem in immunocompromised patients. Areas covered: We reviewed the current knowledge on the impact of chronic viral hepatitis in the hematological setting. Epidemiological features, screening strategies and indications for treatment and monitoring have been explored and commented. Expert commentary: Knowing patient's complete HBV serostatus is mandatory in order to choose between treatment, prophylaxis or a pre-emptive approach. Recent guidelines favor treatment with high barrier molecules in all patients with chronic HBV infection and long lasting prophylaxis with those with inactive or resolved one. With regard to HCV, the new direct-acting antiviral agents have been safely administered in the hematological setting. Their use as first-line single treatment in indolent lymphomas, and combined with chemotherapy in aggressive ones, should be considered. Due to the existing risk of chronic HEV infection in the immunocompromised, screening with serum HEV-RNA should be performed in case of signs and symptoms indicative of hepatitis. In the event of HEV infection, reduction of immunosuppression and, if not feasible or unsuccessful, ribavirin treatment should be prescribed.

Detection of HBV Covalently Closed Circular DNA

Chronic hepatitis B virus (HBV) infection affects approximately 240 million people worldwide and remains a serious public health concern because its complete cure is impossible with current treatments. Covalently closed circular DNA (cccDNA) in the nucleus of infected cells cannot be eliminated by present therapeutics and may result in persistence and relapse. Drug development targeting cccDNA formation and maintenance is hindered by the lack of efficient cccDNA models and reliable cccDNA detection methods. Southern blotting is regarded as the gold standard for quantitative cccDNA detection, but it is complicated and not suitable for high-throughput drug screening, so more sensitive and simple methods, including polymerase chain reaction (PCR)-based methods, Invader assays, in situ hybridization and surrogates, have been developed for cccDNA detection. However, most methods are not reliable enough, and there are no unified standards for these approaches. This review will summarize available methods for cccDNA detection. It is hoped that more robust methods for cccDNA monitoring will be developed and that standard operation procedures for routine cccDNA detection in scientific research and clinical monitoring will be established.

Complete hepatitis B virus prophylaxis withdrawal in hepatitis B surface antigen-positive liver transplant recipients after longterm minimal immunosuppression

Tailored approaches have been attempted to prevent hepatitis B virus (HBV) reinfection in antibodies against hepatitis B surface antigen (HBsAg)-positive liver transplantation (LT) recipients in order to minimize the use of hepatitis B immune globulin (HBIG) and nucleoside analogues (NAs). We report the results of complete HBV prophylaxis withdrawal after a follow-up of at least 6 years in LT recipients with undetectable serum HBV DNA and intrahepatic total HBV DNA and covalently closed circular DNA at LT. We included 30 HBsAg positive, hepatitis B e antigen-negative recipients, 6 with hepatitis C virus and 7 with hepatitis D virus coinfection, who had received HBIG plus NA for at least 5 years after LT. Stepwise HBIG and NA withdrawal was performed in two 6-month periods under strict monitoring of HBV virology. All patients underwent a clinical, biochemical, and virological follow-up at 3-6 month intervals. HBV recurrence (HBsAg seroreversion ± detectable HBV DNA) occurred in 6 patients: in 1 patient after HBIG interruption and in 5 after both HBIG and NA cessation. Only 3 patients required reinstitution of HBV prophylaxis because of persistent HBV replication, and all achieved optimal control of HBV infection and did not experience clinical events. The other who recurred showed only short-lasting HBsAg positivity, with undetectable HBV DNA, followed by spontaneous anti-HBs seroconversion. An additional 15 patients mounted an anti-HBs titer, without previous serum HBsAg detectability. At the end of follow-up, 90% of patients were still prophylaxis-free, 93.3% were HBsAg negative, and 100% were HBV DNA negative; 60% had anti-HBs titers >10 IU/L (median, 143; range, 13-1000). This small series shows that complete prophylaxis withdrawal is safe in patients transplanted for HBV-related disease at low risk of recurrence and is often followed by spontaneous anti-HBs seroconversion. Further studies are needed to confirm this finding. Liver Transplantation 22 1205-1213 2016 AASLD.

The detection of (total and ccc) HBV DNA in liver transplant recipients with hepatitis B vaccine against HBV reinfection

To investigate the levels of hepatitis B virus total DNA (HBV DNA) and covalently closed circular (ccc) DNA in liver transplant recipients who received hepatitis B vaccination, including responders and non-responders, following liver transplantation due to hepatitis B-related diseases and to investigate the efficacy of hepatitis B immune reconstitution against HBV reinfection. Twenty responders and 34 non-responders were enrolled in the present study. The levels of HBV total DNA and ccc DNA in peripheral blood mononuclear cells (PBMCs) and the liver and plasma were detected by real-time polymerase chain reaction (PCR). Fifty-three blood samples and 38 liver allograft tissues were acquired. For the responders, the mean serum titer for anti-HBs (antibodies against hepatitis B surface antigen) was 289 (46.64-1000) IU/ml. Also for the responders, HBV total DNA was detected in PBMCs for one recipient and in the liver for another recipient, but ccc DNA was not detected in either of those 2 recipients. For the non-responders, HBV total DNA was detected in PBMCS for 2 recipients, neither of whom had ccc DNA. Also for the non-responders, HBV total DNA was detected in the livers of 3 recipients, 2 of whom also had ccc DNA. All responders had discontinued hepatitis B immunoglobulin (HBIG), and 13 responders had discontinued antiviral agents. One responder experienced HBV recurrence during the follow-up period. For the majority of liver transplant recipients, no HBV total DNA or ccc DNA was detected in the blood or liver. The lack of HBV total DNA and ccc DNA both in PBMCs and the liver in liver transplant recipients who received hepatitis B vaccination to prevent HBV reinfection should be a prerequisite for the withdrawal of HBIG and/or antiviral agents.

Enhancement of Programmed Death Ligand 2 on Hepatitis C Virus Infected Hepatocytes by Calcineurin Inhibitors

Post orthotopic liver transplantation (OLT) viral hepatitis is an immunological condition where immune cells induce hepatitis during conditions of immune-suppression. The immune-regulatory programmed death-1 (PD-1)/PD-ligand 1 system is acknowledged to play important roles in immune-mediated diseases. However, the PD-1/PD-L2 interaction is not well characterized, with PD-L2 also exhibiting an immunostimulatory function. We hypothesized that this atypical molecule could affect the recurrence of post-OLT hepatitis. To test this hypothesis, we conducted immunohistochemical staining analysis and in vitro analysis of PD-L2.

Translational study of before and after liver transplantation for hepatitis B and C shows that calcineurin inhibitors (CNI) increase the expression of functional programmed death-1 on hepatocytes. The results suggest an important contribution of CNI on post transplant hepatitis occurrence and severity.

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

Hepatitis B virus (HBV) remains a public health concern with 240 million people affected worldwide. HBV is an hepadnavirus that replicates its genome in hepatocytes. One of the key steps of the viral life cycle is the formation of cccDNA - covalently closed circular DNA - in the nucleus, the equivalent of a viral mini-chromosome that acts as a template for subsequent virus replication. Current antiviral medications are not effective in eradicating cccDNA, which can persist in the infected liver even in the absence of detectable HBV DNA or HBsAg in the blood. cccDNA cannot be measured in serum, and few surrogate markers have been proposed. Persistent cccDNA has been associated with various clinical events, including viral reactivation induced by immunosuppressive therapies, HBV recurrence after liver transplantation and hepatocellular carcinoma (HCC). cccDNA remains the main target to achieve a cure of HBV infection, thus extensive efforts are being made to develop new antiviral concepts to degrade or silence cccDNA.

Correlation between risk of hepatitis B virus recurrence and tissue expression of covalently closed circular DNA in living donor liver transplant recipients treated with high-dose hepatitis B immunoglobulin

BACKGROUND AND AIMS

Despite the application of prophylaxis, the risk of hepatitis B virus (HBV) recurrence remains. However, actual mechanism(s) and definite risk factor(s) are obscure. The present study examined the correlation between the HBV load in liver explants and post-liver transplant (OLT) HBV recurrence.

METHODS

HBV DNA was extracted from liver tissue taken from 50 living donor OLT (LDLT) patients using the QuickGene DNA Tissue Kit S (Fujifilm, Tokyo, Japan) and subjected to real-time polymerase chain reaction with the following primers: 5'-CACATGGCCTCCAAGGAGTAA-3' (forward primer) and 5'-TGAGGGTCTCTCTCTTCCTCTTGT-3' (reverse primer). To prevent HBV infection, patients were treated daily with high-dose (10,000 IU) hepatitis B immunoglobulin (HBIG) for the first week after LDLT. They then received weekly doses for the next month and then monthly doses for ≤1 year. If the anti-hepatitis surface antigen antibody titer was <1,000 IU/L, an antiviral agent (AVA) was added to the regimen.

RESULTS

The mean (±SD) tissue HBV DNA and covalently closed circular DNA (cccDNA) loads were -0.8 ± 1.2 (range, -2.9 to 2.6) and -2.3 ± 1.1 (range, -4.6 to 0.6) log10 copies/cell, respectively. There was a significant correlation between serum and tissue HBV DNA (r = 0.65; P = .00) and cccDNA concentrations (r = 0.55; P = .00). Six patients suffered HBV recurrence and 9 required additional AVA. There was no direct correlation between HBV recurrence and tissue cccDNA concentration. However, the concentration of cccDNA was significantly greater those patients suffering recurrence and receiving AVA treatment (high-risk group).

CONCLUSION

High tissue cccDNA concentrations may be a risk factor for HBV recurrence despite high-dose HBIG prophylaxis.

Development of magnetic capture hybridization and quantitative polymerase chain reaction for hepatitis B virus covalently closed circular DNA

BACKGROUND

Hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) served as a vital role in the life cycle of the virus and persistent infection. However, specific and quantitative methods for cccDNA detection have not been available.

OBJECTIVES

Our aim was to develop and primarily evaluate a quantitative method for HBV cccDNA based on magnetic capture hybridization and quantitative PCR technology.

MATERIALS AND METHODS

The functionalized-nanoparticles specifically to capture HBV cccDNA, located on both sides of relaxed circle DNA (rcDNA) gap, were designed. Then, magnetic capture hybridization and quantitative PCR (MCH-qPCR) assay were developed and its performance was primarily evaluated with cccDNA standards and serum samples of patients with chronic hepatitis B.

RESULTS

Specific nanoparticles of cccDNA capture were prepared and a magnetic capture hybridization and quantitative assay method for cccDNA was developed successfully. The limit of detection was 90 IU/mL, and a good linear relationship in the range of 10(2)-10(6) IU/mL was revealed (r(2) = 0.994) with the MCH-qPCR. Compared with directly real-time PCR, a high content of HBV DNA did not affect the detection of cccDNA for the MCH-qPCR method, and there was no cross-reactivity between cccDNA and rcDNA.

CONCLUSIONS

The novel MCH-qPCR method has good sensitivity and specificity. It could meet the requirement of clinical routine detection.

A novel method for detection of HBVcccDNA in hepatocytes using rolling circle amplification combined with in situ PCR

BACKGROUND

Intrahepatic hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) is the original template for HBV replication. The persistence of cccDNA is responsible for the recurrence of HBV infection. The detection of cccDNA can help the development of new antiviral drugs against HBV replication links, and reduce the resistance and recurrence as well as to discover extrahepatic HBV infection. In situ polymerase chain reaction (IS-PCR) can be used to determine the distribution and localization of cccDNA in liver tissues, but it is hampered by its low sensitivity and specificity. We developed a novel method to detect HBV cccDNA using rolling circle amplification (RCA) combined with IS-PCR.

METHODS

Biopsy liver tissues were obtained from 26 patients with HBV infection, including 10 chronic hepatitis B (CHB), 6 liver cirrhosis (LC) and 10 hepatocellular carcinoma (HCC) patients. Four pairs of primers were designed to mediating RCA for the first round amplification of HBV cccDNA specifically. The liver tissue sections from patients were treated by plasmid-safe ATP-dependent DNase (PSAD) prior to RCA. After RCA, HBV cccDNA was further amplified by a pair of selective primers labeled digoxigenin that target the gap region between the two direct repeat regions (DR1 and DR2) of the virus via IS-PCR.

RESULTS

HBVcccDNA was expressed and located in hepatocyte nucleus in 19 patients (73.07%). Compared with the IS-PCR, the introduction of RCA increase the limit of detection. RCA combined with IS-PCR yielded strong positive signals in HCC liver tissue in spite of low copy number cccDNA (2 copies of target sequence per cell), meanwhile, no positive signal was detected via negative control.

CONCLUSIONS

RCA combined with IS-PCR is an effective and practicable method which could detect the presence of low copy number of cccDNA sensitively and specifically, and reflect the relationship between cccDNA expression level and liver tissue pathological characteristics.

Prophylaxis against Recurrence in Liver Transplantation Patients with Hepatitis B Virus: What is New?

Hepatitis B virus (HBV) causes an endemic infection that affects nearly 2 billion patients worldwide. It is one of the leading causes of liver cirrhosis, hepatocellular carcinoma (HCC), and liver transplantation (LT). Recurrence of HBV infection after LT is due to specific HBV-host genome interactions. Although hepatitis B immunoglobulin treatment constituted the backbone of HBV recurrence, use of the nucleoside and nucleotide analogs (especially the ones with a higher genetic barrier to resistance), either alone or in combination, offer us new and powerful options in overcoming this serious issue.

Prediction of occult hepatitis B virus infection in liver transplant donors through hepatitis B virus blood markers

BACKGROUND

Occult hepatitis B virus infection is defined as detectable HBV-DNA in liver of HBsAg-negative individuals, with or without detectable serum HBV-DNA. In deceased liver donors, results of tissue analysis cannot be obtained prior to allocation for liver transplantation.

AIMS

we investigated prevalence and predictability of occult hepatitis B using blood markers of viral exposure/infection in deceased liver donors.

METHODS

In 50 consecutive HBsAg-negative/anti-HBc-positive and 20 age-matched HBsAg-negative/anti-HBc-negative donors, a nested-PCR assay was employed in liver biopsies for diagnosis of occult hepatitis B according to Taormina criteria. All donors were characterized for plasma HBV-DNA and serum anti-HBs/anti-HBe.

RESULTS

In liver tissue, occult hepatitis B was present in 30/50 anti-HBc-positive (60%) and in 0/20 anti-HBc-negative donors (p<0.0001). All anti-HBc-positive donors with detectable HBV-DNA in plasma (n=5) or anti-HBs>1,000 mIU/mL (n=5) eventually showed occult infection, i.e, 10/30 occult hepatitis B-positive donors which could have been identified prior to transplantation. In the remaining 40 anti-HBc-positive donors, probability of occult infection was 62% for anti-HBe-positive and/or anti-HBs ≥ 58 mIU/mL; 29% for anti-HBe-negative and anti-HBs<58 mIU/mL.

CONCLUSIONS

In deceased donors, combining anti-HBc with other blood markers of hepatitis B exposure/infection allows to predict occult hepatitis B with certainty and speed in one third of cases. These findings might help refine the allocation of livers from anti-HBc-positive donors.

Analysis of hepatitis B virus intrahepatic covalently closed circular DNA and serum viral markers in treatment-naive patients with acute and chronic HBV infection

Background

This study aimed to investigate the relationships of intrahepatic cccDNA with serum HBsAg and with HBV DNA in treatment-naive patients throughout acute and chronic HBV infection.

Methods

A total of 120 patients who had a liver biopsy were enrolled, including 19 with acute hepatitis B (AHB), and 101 patients with chronic HBV infection (CHB) of whom were 10 in immune-tolerant (IT) phase, 59 in immune-clearance (IC) phase, 8 in low-replicative (LR) phase, and 24 in HBeAg-negative hepatitis (ENH) phase. Intrahepatic cccDNA, serum HBsAg and serum HBV DNA levels were comparatively analyzed.

Results

The median intrahepatic cccDNA levels were 0.18 4.80, 3.81, 0.22 and 0.97 copies/cell for patients with AHB, CHB-IT, CHB-IC, CHB-LR, and CHB-ENH, respectively. In AHB patients, intrahepatic cccDNA was positively correlated with serum HBsAg (r = 0.665, P = 0.003), as well as serum HBV DNA (r = 0.536, P = 0.022). In CHB patients, intrahepatic cccDNA was positively correlated with serum HBsAg in the IC phase (r = 0.392, P = 0.005), and with serum HBV DNA in the IC phase (r = 0.301, P = 0.036) and ENH phase (r = 0.588, P = 0.013). HBV replicative efficiency, defined as the ratio of serum HBV DNA to intrahepatic cccDNA, was obviously lower in AHB and CHB-LR patients than in CHB-IT, CHB-IC and CHB-ENH patients (0.70 and 0.53 vs. 1.12, 1.09 and 0.99, P<0.001, values were logarithmic transformed for analysis). In CHB-IC patients, HBV replicative efficiency was positively correlated with histological activity index of liver inflammation (r = 0.308, P = 0.009).

Conclusion

Serum HBsAg and HBV DNA levels may reflect the amount of active intrahepatic cccDNA in treatment-naive AHB and CHB-IC patients. Reduced intrahepatic cccDNA and HBV replicative efficiency may imply effective immune control of HBV infection.

The option of HBIG-free prophylaxis against recurrent HBV

Since the early 1990's, hepatitis B immune globulin (HBIG) has been central to the prevention of hepatitis B virus (HBV) recurrence after liver transplantation. When used in combination with oral nucleos(t)ide analogues, HBIG prevents reinfection with HBV in ⩾90% of transplant recipients. While HBIG is highly efficacious, its use is undermined by its high cost. Because of this limitation, there have been many studies of alternative regimens seeking to minimize the dose or duration of HBIG without sacrificing low HBV recurrence rates. Toward that goal, lower dose intramuscular HBIG in combination with oral nucleos(t)ide analogues has been shown to be highly efficacious in preventing disease recurrence and represents a significant cost savings when compared with high dose intravenous administration. The withdrawal of HBIG after a defined course of combination HBIG and oral antivirals has also been shown to be effective, particularly if combination antiviral therapy is used. The ability to achieve undetectable HBV DNA levels pre-transplantation in the majority of patients may contribute to the high efficacy of these HBIG "light" regimens. Additionally, the success of antiviral rescue therapy for those patients who fail prophylaxis and develop recurrent HBV infection post-transplant has provided the impetus to move increasingly towards HBIG-free approaches. New techniques to detect occult HBV in hepatic and extrahepatic sites may allow clinicians to define a subgroup of patients in whom withdrawal of HBIG or all prophylaxis may be applicable.

Relationship between HBV cccDNA expression in the human ovary and vertical transmission of HBV

This study aimed to investigate the relationship between hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) in the ovary and vertical transmission of HBV. HBV DNA and HBV cccDNA were assayed in the ovaries of 33 pregnant women who were positive for HBV DNA. The HBVM (HBV markers, including HBsAg, HBsAb, HBeAg, HBeAb, HBcAb) level and the HBV DNA content in peripheral blood of infants were measured. The overall positive rate of HBV DNA and HBV cccDNA in samples was 51·52% (17/33). The intrauterine infection rate of the infants was 12·12% (4/33). When HBV DNA and HBV cccDNA were both positive, the intrauterine infection rate of infants was significantly higher than when they were both negative (P<0·05). Levels of HBV cccDNA and the rate of positive samples were significantly higher in mothers with infants with intrauterine infection than in those without (P<0·01 and P<0·05, respectively). HBV can infect the human ovary and may transmit to the filial generation via the ovum.

Safety of complete and sustained prophylaxis withdrawal in patients liver-transplanted for HBV-related cirrhosis at low risk of HBV recurrence

BACKGROUND & AIMS

HBV reactivation after liver transplantation may be related to persistence of covalently closed circular (ccc) DNA. We investigated the safety of HBV prophylaxis withdrawal in selected HBV transplanted patients.

METHODS

Thirty patients transplanted 64-195months earlier (23 males, median age 56yrs), HBsAg-positive, HBeAg, and HBV-DNA negative at transplant (43% HCV/HDV co-infected), with undetectable intrahepatic total and ccc-DNA were enrolled. All patients underwent HBIg withdrawal and continued lamivudine with monthly HBsAg and HBV-DNA monitoring and sequential liver biopsies. Those with confirmed intrahepatic total and ccc-DNA undetectability 24weeks after stopping HBIg, also underwent lamivudine withdrawal and were followed-up without prophylaxis.

RESULTS

Twenty-five patients did not exhibit signs of HBV recurrence after prophylaxis withdrawal (median follow-up 28.7months, range 22-42). Five patients became HBsAg-positive: one early after HBIg withdrawal, the other four after HBIG and lamivudine withdrawal. None of these patients experienced clinically relevant events. In the first patient, HBIg were reinstituted with prompt HBsAg negativization. Of the other four, one remained HBsAg-positive with detectable HBV-DNA and mild ALT elevation and was successfully treated with tenofovir. In the remaining three, HBsAg positivity was transient and followed by anti-HBs seroconversion, thus no antiviral treatment was needed.

CONCLUSIONS

Patients with undetectable HBV viremia at transplant and no evidence of intrahepatic total and cccDNA may safely undergo cautious weaning of prophylaxis, showing low rate of HBV recurrence after a 2 year follow-up. Undetectability of intrahepatic ccc-DNA may help to identify patients at low-risk of recurrence, yet studies with longer follow-up are needed.

Quantitation of HBV covalently closed circular DNA in micro formalin fixed paraffin-embedded liver tissue using rolling circle amplification in combination with real-time PCR

BACKGROUND

The study aimed to develop an effective method to quantitate HBV covalently closed circular DNA (cccDNA) using small section of formalin fixed paraffin-embedded (FFPE) liver biopsy.

METHODS

Plasmid-safe ATP-dependent DNase (PSAD)-treated samples were subjected to rolling circle amplification (RCA) prior to real-time PCR mediated by cccDNA-selective primers. Human beta-actin gene was used as a reference control.

RESULTS

Compared to the classical method, i.e., PSAD digestion+real-time PCR, introduction of RCA increased the lower limit of detection for about 2 logs with good inter- and intra-assay reproducibility. HBV cccDNA was detected in 91.5% (119/130) of the FFPE samples. The cccDNA levels (copy/cell) between FFPE liver tissues and fresh frozen counterpart tissues were comparable. The median of cccDNA level in HBeAg-positive patients was higher than that in HBeAg-negative ones (52.60 vs. 31.25copies/cell, P<0.01). Intrahepatic cccDNA level was positively correlated with intrahepatic HBV total DNA level, but not obviously correlated with serum HBV DNA or alanine aminotransferase levels.

CONCLUSIONS

The method could sensitively and specifically quantitate intrahepatic HBV cccDNA in micro FFPE liver biopsy tissue for evaluation of HBV replication status in the liver.