Hepatitis B virus reactivation after radiotherapy for hepatocellular carcinoma and efficacy of antiviral treatment: A multicenter study

Management of Chronic Liver Disease in Patients with Hepatocellular Carcinoma

Management of cirrhosis sequelae is critical in providing the most options for patients with hepatocellular carcinoma (HCC). Compensated liver disease is the ideal state for HCC patients who may require resection, locoregional therapies, or liver transplantation. Portal hypertension complications, suboptimal nutrition, and frailty are common barriers to various HCC treatments. For patients with advanced HCC, systemic therapies are altering the approach to multifocal, unresectable HCC, but similar barriers exist related to managing cirrhosis complications. Frequently, managing the underlying liver disease etiology is a key component to enabling HCC treatment.

The occurrence of immune-related adverse events is an independent risk factor both for serum HBsAg increase and HBV reactivation in HBsAg-positive cancer patients receiving PD-1 inhibitor combinational therapy

BACKGROUND

Previous studies have suggested the potential of PD-1/PD-L1 inhibitors in the treatment of chronic HBV infection. However, since phase III clinical trials have not yet been announced, additional clinical insights may be obtained by observing changes in serum hepatitis B surface antigen (HBsAg) and HBV-DNA levels in cancer patients undergoing PD-1 inhibitor therapy.

OBJECTIVE

To explore the effects of PD-1 inhibitor combinational therapy on serum HBsAg and HBV-DNA levels, investigate the incidence of HBsAg loss, HBV reactivation (HBVr), and immune-related adverse events (irAEs), and identify the risk factors associated with significant HBsAg fluctuations and HBVr.

METHODS

A retrospective study including 1195 HBsAg-positive cancer patients who received PD-1 inhibitors between July 2019 and June 2023 was conducted, and 180 patients were enrolled in this study. Serum HBsAg levels before and after PD-1 inhibitor administration were compared across different subgroups. The Pearson χ2 or Fisher exact test was performed to investigate the relationships between categorical variables. Univariable and multivariable analysis were performed to identify the risk factors associated with significant HBsAg fluctuations and HBVr.

RESULTS

With the concurrent use of antiviral agents, serum HBsAg levels decreased (Z=-3.966, P < 0.0001) in 129 patients and increased (t=-2.047, P=0.043) in 51 patients. Additionally, 7 patients (3.89%) achieved serum HBsAg loss. Virus replication was suppressed in most of the enrolled patients. When divided patients into different subgroups, significant HBsAg decreases after PD-1 inhibitor administration were discovered in lower baseline HBsAg group (Z=-2.277, P=0.023), HBeAg-seronegative group (Z=-2.200, P=0.028), non-irAEs occurrence group (Z=-2.007, P=0.045) and liver cancer group (Z=-1.987, P=0.047). Of note, 11 patients and 36 patients experienced HBVr (6.11%) and irAEs (20%), respectively, which could lead to discontinuation or delayed use of PD-1 inhibitors. After multivariable analysis, HBeAg-seropositive (OR, 7.236 [95% CI, 1.757-29.793], P=0.01) and the occurrence of irAEs (OR, 4.077 [95% CI, 1.252-13.273], P=0.02) were identified as the independent risk factors for significant HBsAg increase, the occurrence of irAEs (OR, 5.560 [95% CI, 1.252-13.273], P=0.01) was identified as the only independent risk factor for HBVr.

CONCLUSION

PD-1 inhibitors combined with nucleos(t)ide analogues (NAs) may exert therapeutic potential for chronic HBV infection in cancer patients. However, attention also should be paid to the risk of significant elevation in HBsAg levels, HBVr, and irAEs associated with PD-1 inhibitor combinational therapy.

5-FU promotes HBV replication through oxidative stress-induced autophagy dysfunction

BACKGROUND & AIMS

Hepatitis B virus (HBV) reactivation is a major problem that must be overcome during chemotherapy for HBV-related hepatocellular carcinoma (HCC). However, the mechanism underlying chemotherapy-associated HBV reactivation is still not fully understood, hindering the development of improved HBV-related HCC treatments.

METHODS

A meta-analysis was performed to assess the HBV reactivation risk during transcatheter arterial chemoembolization (TACE). To investigate the regulatory effects and mechanisms of 5-FU on HBV replication, an HBV mouse model was established by pAAV-HBV1.2 hydrodynamic injection followed by intraperitoneal 5-FU injection, and different in vitro models (HepG2.2.15 or Huh7 cells) were established. Realtime RT‒qPCR, western blotting, luciferase assays, and immunofluorescence were used to determine viral parameters. We also explored the underlying mechanisms by RNA-seq, oxidative stress evaluation and autophagy assessment.

RESULTS

The pooled estimated rate of HBV reactivation in patients receiving TACE was 30.3 % (95 % CI, 23.1%-37.4 %). 5-FU, which is a chemotherapeutic agent commonly used in TACE, promoted HBV replication in vitro and in vivo. Mechanistically, 5-FU treatment obviously increased autophagosome formation, as shown by increased LC3-II levels. Additionally, 5-FU impaired autophagic degradation, as shown by marked p62 and mCherry-GFP-LC3 upregulation, ultimately promoting HBV replication and secretion. Autophagy inhibition by 3-methyladenine or chloroquine significantly altered 5-FU-induced HBV replication. Furthermore, 5-FU-induced autophagy and HBV replication were markedly attenuated with a reactive oxygen species (ROS) scavenger.

CONCLUSIONS

Together, our results indicate that ROS-induced autophagosome formation and autophagic degradation play a critical role in 5-FU-induced HBV reactivation.

2022 KLCA-NCC Korea practice guidelines for the management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the fourth most common cancer among men in South Korea, where the prevalence of chronic hepatitis B infection is high in middle and old age. The current practice guidelines will provide useful and sensible advice for the clinical management of patients with HCC. A total of 49 experts in the fields of hepatology, oncology, surgery, radiology, and radiation oncology from the Korean Liver Cancer Association-National Cancer Center Korea Practice Guideline Revision Committee revised the 2018 Korean guidelines and developed new recommendations that integrate the most up-to-date research findings and expert opinions. These guidelines provide useful information and direction for all clinicians, trainees, and researchers in the diagnosis and treatment of HCC.

2022 KLCA-NCC Korea Practice Guidelines for the Management of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the fourth most common cancer among men in South Korea, where the prevalence of chronic hepatitis B infection is high in middle and old age. The current practice guidelines will provide useful and sensible advice for the clinical management of patients with HCC. A total of 49 experts in the fields of hepatology, oncology, surgery, radiology, and radiation oncology from the Korean Liver Cancer Association-National Cancer Center Korea Practice Guideline Revision Committee revised the 2018 Korean guidelines and developed new recommendations that integrate the most up-to-date research findings and expert opinions. These guidelines provide useful information and direction for all clinicians, trainees, and researchers in the diagnosis and treatment of HCC.

2022 KLCA-NCC Korea practice guidelines for the management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the fourth most common cancer among men in South Korea, where the prevalence of chronic hepatitis B infection is high in middle and old age. The current practice guidelines will provide useful and sensible advice for the clinical management of patients with HCC. A total of 49 experts in the fields of hepatology, oncology, surgery, radiology, and radiation oncology from the Korean Liver Cancer Association-National Cancer Center Korea Practice Guideline Revision Committee revised the 2018 Korean guidelines and developed new recommendations that integrate the most up-to-date research findings and expert opinions. These guidelines provide useful information and direction for all clinicians, trainees, and researchers in the diagnosis and treatment of HCC.

Clinical Outcomes of Hepatitis B Virus-Related Hepatocellular Carcinoma Patients with Undetectable Serum HBV DNA Levels

BACKGROUND AND AIMS

Some hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) patients show undetectable serum HBV DNA levels at HCC diagnosis. The risk of HBV reactivation and its impact on clinical outcomes are not well-unknown.

METHODS

This retrospective cohort study included a total of 985 HBV-related HCC patients with undetectable serum HBV DNA levels (< 12 IU/mL) at HCC diagnosis (112 were antiviral treatment (AVT)-naïve; 873 were receiving AVT). Incidence and risk factors for HBV reactivation (re-detection of HBV DNA in serum) during follow-up, as well as its association to overall survival, were assessed.

RESULTS

During a median of 33.4 months of follow-up (range: 0.2-124.2 months), HBV reactivation was observed in 279 patients. HBV reactivation rate was significantly lower for patients receiving AVT than AVT-naïve patients (three-year cumulative incidence rate: 27.3% versus 56.0%; P < 0.001). In multivariable-adjusted analysis, the risk of HBV reactivation was lower for those receiving AVT compared to AVT-naïve patients (adjusted hazard ratio: 0.39, 95% confidence interval: 0.29-0.54). Overall survival was significantly lower for those experiencing HBV reactivation than those who did not (71.5% and 85.7% at five-year) and was associated with higher risk of overall mortality (adjusted hazard ratio: 5.15, 95% confidence interval: 3.60-7.38).

CONCLUSION

More than half of AVT-naïve patients experienced HBV reactivation within three years, which was associated with increased risk of overall mortality. The risk of HBV reactivation was lower for those receiving AVT, suggesting that prompt AVT needs to be considered for AVT naïve HBV-related HCC patients with undetectable HBV DNA levels.

Clinical consensus statement: Selective internal radiation therapy with yttrium 90 resin microspheres for hepatocellular carcinoma in Asia

BACKGROUND

Hepatocellular carcinoma (HCC) is subject to different management approaches and guidelines according to Eastern and Western therapeutic algorithms. Use of selective internal radiation therapy (SIRT) with resin yttrium 90 microspheres for HCC has increased in Asia in recent years, without clearly defined indications for its optimal application. The objective of this systematic review and expert consensus statement is to provide guidance and perspectives on the use of SIRT among patients with HCC in Asia.

MATERIALS AND METHODS

A systematic literature review identified current publications on HCC management and SIRT recommendations. A group of 10 experts, representing stakeholder specialties and countries, convened between August 2020 and March 2021 and implemented a modified Delphi consensus approach to develop guidelines and indications for use of SIRT for HCC in Asia. Final recommendations were organized and adjudicated based on the level of evidence and strength of recommendation, per approaches outlined by the American College of Cardiology/American Heart Association and Oxford Centre for Evidence-Based Medicine.

RESULTS

The experts acknowledged a general lack of evidence relating to use of SIRT in Asia and identified as an unmet need the lack of phase 3 randomized trials comparing clinical outcomes and survival following SIRT versus other therapies for HCC. Through an iterative process, the expert group explored areas of clinical relevance and generated 31 guidance statements and a patient management algorithm that achieved consensus.

CONCLUSION

These recommendations aim to support clinicians in their decision-making and to help them identify and treat patients with HCC using SIRT in Asia. The recommendations also highlight areas in which further clinical trials are needed to define the role of SIRT in management of HCC among Asian populations.

Risk of HBV reactivation during therapies for HCC: A systematic review

BACKGROUND AND AIMS

Treatment for HCC has evolved rapidly, but the risk of HBV reactivation to new therapies is unclear. We systematically reviewed data on HBV reactivation in patients receiving HCC therapy in relation to use of HBV antiviral prophylaxis.

APPROACH AND RESULTS

A literature search was performed to identify all published studies including HBsAg-positive patients with HCC providing data on HBV reactivation. Forty-one studies with 10,223 patients, all from Asia, were included. The pooled HBV reactivation rate was 5% in patients receiving no specific HCC therapy and was higher in patients undergoing surgical resection (16%), transarterial chemoembolization (19%), or radiotherapy (14%) and intermediate in patients treated with local ablation therapy (7%) or systemic agents (7%). HBV reactivation rates were higher in those without compared to those with HBV prophylaxis (ablation, 9% versus 0%; resection, 20% versus 3%; chemoembolization, 23% versus 1%; external radiotherapy alone, 18% versus 0%; systemic therapy, 9% versus 3%). HBV-related biochemical reactivation rates varied between 6%-11% and 2% in patients receiving HCC therapies with high and intermediate HBV reactivation risk, respectively. Liver decompensation and death were rarely reported (0%-3%) and only in patients receiving HCC treatment with high HBV reactivation risk.

CONCLUSIONS

HBsAg-positive patients with HCC are at high or intermediate risk of HBV reactivation depending on the type of HCC therapy. Nucleos(t)ide analogue prophylaxis reduces the risk of HBV reactivation, practically eliminates the risk of hepatitis flare, and should be administered regardless of HCC treatment.

Controversies in the Management of Hepatitis B: Hepatocellular Carcinoma

Hepatitis B is the leading cause of hepatocellular cancer (HCC) worldwide. Untreated, annual HCC incidence rates in chronic hepatitis B subjects are 0.4% in noncirrhotics and 2% to 3% in cirrhotics. Surveillance with ultrasound with/without α-fetoprotein at 6-month intervals is recommended in at-risk persons including children. Antiviral therapy in chronic hepatitis B with entecavir or tenofovir significantly lowers the risk of HCC across all stages of liver disease, and lowers the risk of HCC recurrence following curative therapy. There are insufficient data to recommend use of tenofovir over entecavir in the prevention of de novo or recurrent HCC postcurative therapy.

Advances in treatment and prevention of hepatitis B

Chronic hepatitis B (CHB) continues to contribute to worldwide morbidity and mortality significantly. Scientists, clinicians, pharmaceutical companies, and health organizations have dedicated substantial Intellectual and monetary resources to finding a cure, increasing immunization rates, and reducing the global burden of CHB. National and international health-related organizations including the center for disease control, the national institute of health, the American Association for the study of liver disease (AASLD), The European association for the study of the Liver (EASL), The Asia Pacific association for the study of the Liver (APASL) and the world health organization release periodic recommendations for disease prevention and treatment. Our review of the most recent guidelines by EASL, AASLD, APASL, and Taiwan Association for the Study of the Liver revealed that an overwhelming majority of cited studies were published before 2018. We reviewed Hepatitis B-related literature published 2018 onwards to identify recent developments and current barriers that will likely direct future efforts towards eradicating hepatitis B. The breakthrough in our understanding of the hepatitis B virus life cycle and resulting drug development is encouraging with significant room for further progress. Data from high-risk populations, most vulnerable to the devastating effects of hepatitis B infection and reactivation remain sparse. Utilization of systems approach, optimization of experimental models, identification and validation of next-generation biomarkers, and precise modulation of the human immune response will be critical for future innovation. Within the foreseeable future, new treatments will likely complement conventional therapies rather than replace them. Most Importantly, pragmatic management of CHB related population health challenges must be prioritized to produce real-world results.

Evaluation of the Benefits of TACE Combined with Sorafenib for Hepatocellular Carcinoma Based on Untreatable TACE (unTACEable) Progression

Purpose

Outcomes after the treatment for unresectable or advanced-stage hepatocellular carcinoma (HCC) are unsatisfied. We evaluated the therapeutic benefits of a combination therapy strategy for these patients through transarterial chemoembolization (TACE) plus sorafenib.

Patients and Methods

In total, 85 patients with HCC classified as intermediate and advanced stage from June 2012 to November 2017 were retrospectively investigated. We divided patients into the monotherapy (n=43; TACE alone) and combined therapy (n=42; TACE plus sorafenib) groups.

Results

Compared with the TACE alone group, the TACE plus sorafenib experienced significantly prolonged progression-free survival (PFS) (mean 21 months vs 12 months; P = 0.0005) and overall survival (OS) (mean 32 months vs 21 months; P = 0.0157). The disease control rate (DCR) of TACE plus sorafenib group was 80.95%, which was significantly increased than the TACE alone group (55.81%) (P<0.05), as well as objective response rate (ORR) (23.81% vs 16.28%). Besides, the rates of liver-related AEs and liver failure in the TACE plus sorafenib group were not increased in contrast to TACE alone group, and there were no new safety concerns. To sum up, the superiority of combination therapy with significantly prolonging progression-free and overall survival was observed, meanwhile finding a significant increase in tumor response rate and manageable safety in the combined therapy in contrast to the monotherapy group.

Conclusion

Based on unTACEble progression, the superiority of the combination therapy is that TACE plus sorafenib has been bringing about significantly better outcomes compared with TACE alone for HCC patients.

Effects of Antiviral Therapy on HBV Reactivation and Survival in Hepatocellular Carcinoma Patients Undergoing Hepatic Artery Infusion Chemotherapy

Background

This study aimed to investigate the influence of hepatic artery infusion chemotherapy (HAIC) on hepatitis B virus (HBV) reactivation in hepatitis B surface antigen (HBsAg) positive patients with primary hepatocellular carcinoma (HCC) as well as evaluate the role of antiviral prophylaxis in these patients.

Methods

We enrolled 170 HBsAg-positive advanced HCC patients receiving HAIC using mFOLFOX regimen, of which 137 patients received antiviral prophylaxis. Risk factors for HBV reactivation were analyzed. The overall survival (OS) from the first application of HAIC were compared between antiviral and non-antiviral groups.

Results

A total of 25 patients (14.7%) developed HBV reactivation after HAIC, of which 16 patients received antiviral treatment and nine patients did not. The incidence of HBV reactivation was 11.7% (16/137) in antiviral group and 27.3% (9/33) in non-antiviral group respectively. No antiviral prophylactic was the only significant risk factor for HBV reactivation (OR=12.35, 95% confidence interval (CI) 4.35–33.33, p<0.001). Patients in antiviral group received more cycles of HAIC compared with non-antiviral group (3.11 ± 1.69 vs 1.75 ± 1.18, p<0.05) at the time of HBV reactivated. Seven of the 25 HBV reactivation patients developed hepatitis. OS in antiviral group was significantly longer than that of non-antiviral group (median 16.46 vs 10.68 months; HR=0.57; 95% CI, 0.36–0.91; p<0.05).

Conclusions

HBV reactivation is more prone to occur in the HBsAg-positive HCC patients undergoing HAIC without antiviral prophylaxis. Regular monitoring of HBV DNA and antiviral prophylaxis are suggested to prevent HBV reactivation as well as prolong the OS of these patients.

Name of the Trial Register

HAIC Using Oxaliplatin Plus Fluorouracil/Leucovorin for Patients with Locally Advanced HCC.

Clinical Trial Registration

https://www.clinicaltrials.gov/, identifier NCT 02436044

Hepatitis B Virus Screening and Management for Patients With Cancer Prior to Therapy: ASCO Provisional Clinical Opinion Update

PURPOSE

This Provisional Clinical Opinion update presents a clinically pragmatic approach to hepatitis B virus (HBV) screening and management.

PROVISIONAL CLINICAL OPINION

All patients anticipating systemic anticancer therapy should be tested for HBV by 3 tests-hepatitis B surface antigen (HBsAg), hepatitis B core antibody (anti-HBc) total immunoglobulin (Ig) or IgG, and antibody to hepatitis B surface antigen-but anticancer therapy should not be delayed. Findings of chronic HBV (HBsAg-positive) or past HBV (HBsAg-negative and anti-HBc-positive) infection require HBV reactivation risk assessment.Patients with chronic HBV receiving any systemic anticancer therapy should receive antiviral prophylactic therapy through and for minimum 12 months following anticancer therapy. Hormonal therapy alone should not pose a substantial risk of HBV reactivation in patients with chronic HBV receiving hormonal therapy alone; these patients may follow noncancer HBV monitoring and treatment guidance. Coordination of care with a clinician experienced in HBV management is recommended for patients with chronic HBV to determine HBV monitoring and long-term antiviral therapy after completion of anticancer therapy.Patients with past HBV infection undergoing anticancer therapies associated with a high risk of HBV reactivation, such as anti-CD20 monoclonal antibodies or stem-cell transplantation, should receive antiviral prophylaxis during and for minimum 12 months after anticancer therapy completion, with individualized management thereafter. Careful monitoring may be an alternative if patients and providers can adhere to frequent, consistent follow-up so antiviral therapy may begin at the earliest sign of reactivation. Patients with past HBV undergoing other systemic anticancer therapies not clearly associated with a high risk of HBV reactivation should be monitored with HBsAg and alanine aminotransferase during cancer treatment; antiviral therapy should commence if HBV reactivation occurs.Additional information is available at www.asco.org/supportive-care-guidelines.

Hepatitis B virus persistence and reactivation

Hepatitis B virus (HBV) infection causes chronic hepatitis and has long term complications. Individuals ever infected with HBV are at risk of viral reactivation under certain circumstances. This review summarizes studies on HBV persistence and reactivation with a focus on the definitions and mechanisms. Emphasis is placed on the interplay between HBV replication and host immunity as this interplay determines the patterns of persistence following viral acquisition. Chronic infections exhibit as overt persistence when a defective immune response fails to control the viral replication. The HBV genome persists despite an immune response in the form of covalently closed circular DNA (cccDNA) and integrated DNA, rendering an occult state of viral persistence in individuals whose infection appears to have been resolved. We have described HBV reactivation that occurs because of changes in the virus or the immune system. This review aims to raise the awareness of HBV reactivation and to understand how HBV persists, and discusses the risks of HBV reactivation in a variety of clinical settings.

Analysis of Hepatitis B Virus Reactivation After Radiotherapy in Patients With Hepatocellular Carcinoma Using the Lyman NTCP Model

Purpose:

To analyze the correlation of hepatitis B virus reactivation with patient-related and treatment-related dose–volume factors and to describe the feasibility of hepatitis B virus reactivation analyzed by a normal tissue complication probability model for patients with hepatocellular carcinoma treated with radiotherapy.

Materials and Methods:

Ninety patients with hepatitis B virus-related hepatocellular carcinoma treated with radiotherapy were enrolled in this retrospective study and were followed from June 2009 to December 2015. Of the 90 patients, 78 had received conventional fractionation radiotherapy to a mean dose of 39.6 to 50.4 Gy and 12 patients were scheduled to receive hypofractionation. The physical doses were converted into 2 Gy equivalents for analysis. The parameters, TD₅₀ (1), n, and m, of the Lyman-Kutcher-Burman normal tissue complication probability model were derived using maximum likelihood estimation. Bootstrap and leave-one-out were employed to against model overfitting and improve the model stability.

Results:

Radiation-induced liver diseases were 17.8%, hepatitis B virus reactivation was 22.2%, and hepatitis B virus reactivation-induced hepatitis was 21.1%, respectively. In multivariate analysis, the V_5Gy was associated with hepatitis B virus reactivation; TD₅₀ (1), m, and n were 32.3, 0.55, and 0.71 Gy, respectively, for hepatitis B virus reactivation. Bootstrap and leave-one-out results showed that the hepatitis B virus parameter fits were extremely robust.

Conclusion:

A Lyman-Kutcher-Burman normal tissue complication probability model has been established to predict hepatitis B virus reactivation for patients with hepatocellular carcinoma who received radiotherapy.

What Comes First: Treatment of Viral Hepatitis or Liver Cancer?

Chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infection are the most important underlying causes for the development of hepatocellular carcinoma (HCC) worldwide. Determining the optimal approach for management of the viral infection and the HCC depends on the virus and the stage of the cancer. In patients with HCV-associated HCC, there are multiple reasons to first treat the HCC. Firstly, in case of a curable HCC, the urgency for HCC treatment is important to avoid progression during HCV treatment. Secondly, the presence of HCC itself appears to reduce the rates of sustained virological response (SVR) achieved with direct-acting antivirals (DAAs). And finally, the evidence does not support the concept of an increase in HCC recurrence due to DAAs, so a patient can safely be treated after HCC cure. For patients with very advanced HCC, the benefits of HCV therapy are questionable. In contrast, those who develop HCC in the setting of chronic HBV infection, treatment with nucleoside analogues (NAs) is recommended prior to treating HCC, to prevent further liver injury and reduce the risk for HCC recurrence. Ultimately, earlier diagnosis and treatment of HBV and HCV will hopefully reduce the incidence of HCC worldwide.

Recent Advances in HBV Reactivation Research

Hepatitis B virus (HBV) is an important public health problem that poses a serious threat to human health. HBV reactivation generally occurs in overt or occult HBV infection patients who suffered DDAs, chemotherapy, or immunosuppressive therapy, especially when some solid tumors and leukemia patients are using hormones such as prednisolone and imatinib. The approximate incidence of HBV reactivation ranged from about 10% to 40%. Scientists often explore the molecular mechanisms from both the virus and the host. But some studies have reported that some drugs (cisplatin, rituximab, imatinib, and glucocorticoid) could induce HBV reactivation directly. However, the specific molecular mechanisms were unclear. With the emergence of new antiviral drugs and molecular targeted drugs, the risk of HBV reactivation will increase significantly. Therefore this review was expected to be used to provide recommendations for future research in HBV reactivation.