INASL Guidelines on Management of Hepatitis B Virus Infection in Patients receiving Chemotherapy, Biologicals, Immunosupressants, or Corticosteroids

Prevention and management of hepatitis B virus reactivation in patients with hematological malignancies in the targeted therapy era

Hepatitis due to hepatitis B virus (HBV) reactivation can be serious and potentially fatal, but is preventable. HBV reactivation is most commonly reported in patients receiving chemotherapy, especially rituximab-containing therapy for hematological malignancies and those receiving stem cell transplantation. Patients with inactive and even resolved HBV infection still have persistence of HBV genomes in the liver. The expression of these silent genomes is controlled by the immune system. Suppression or ablation of immune cells, most importantly B cells, may lead to reactivation of seemingly resolved HBV infection. Thus, all patients with hematological malignancies receiving anticancer therapy should be screened for active or resolved HBV infection by blood tests for hepatitis B surface antigen (HBsAg) and antibody to hepatitis B core antigen. Patients found to be positive for HBsAg should be given prophylactic antiviral therapy. For patients with resolved HBV infection, there are two approaches. The first is pre-emptive therapy guided by serial HBV DNA monitoring, and treatment with antiviral therapy as soon as HBV DNA becomes detectable. The second approach is prophylactic antiviral therapy, particularly for patients receiving high-risk therapy, especially anti-CD20 monoclonal antibody or hematopoietic stem cell transplantation. Entecavir and tenofovir are the preferred antiviral choices. Many new effective therapies for hematological malignancies have been introduced in the past decade, for example, chimeric antigen receptor (CAR)-T cell therapy, novel monoclonal antibodies, bispecific antibody drug conjugates, and small molecule inhibitors, which may be associated with HBV reactivation. Although there is limited evidence to guide the optimal preventive measures, we recommend antiviral prophylaxis in HBsAg-positive patients receiving novel treatments, including Bruton's tyrosine kinase inhibitors, B-cell lymphoma 2 inhibitors, and CAR-T cell therapy. Further studies are needed to determine the risk of HBV reactivation with these agents and the best prophylactic strategy.

Treatment Strategies for Chronic Pruritus and Eczema/Dermatitis in Older Adults Under the Category of Chronic Eczematous Eruptions of Aging (CEEA)

Chronic eczematous eruptions of aging (CEEA) refers to a heterogenous group of longstanding, pruritic eczematous dermatoses with an unidentified etiology, or those which do not meet strict disease criteria. The literature has not yet established a single ubiquitous disease or term for these eruptions in adults over the age of 65 years. Instead, CEEA is attributed various names, including immunologic eruption of aging, and eruption of immunosenescence. Atopic dermatitis in the elderly, eczema in the elderly, and late- or adult-onset atopic dermatitis or eczema likely also fall under the umbrella of CEEA, given that older patients often do not meet strict criteria for atopic dermatitis. As a reflection of such terminological heterogeneity, CEEA does not have a standardized workup algorithm. This lack of uniformity can obscure the ability to study and understand appropriate treatments for this condition. Yet, as providers become increasingly aware of CEEA and more comfortable in making this diagnosis in older adults, it is necessary that dermatologists understand the safety and efficacy of common CEEA treatments in this population. Here, we discuss special considerations, challenges, and recommendations for treating older adults with CEEA with topical and systemic therapeutics. We provide an overview of therapeutic strategies and potential barriers to treatment and discuss the essential role of shared decision making when caring for this patient population.

Hepatitis B virus reactivation associated with new classes of immunosuppressants and immunomodulators: A systematic review, meta-analysis, and expert opinion

HBV reactivation (HBVr) can be prevented by nucleos(t)ide analogues (NAs). We conducted a systematic review and meta-analysis on the risk of HBVr associated with new classes of immunosuppressive and immunomodulatory therapies and developed guidance on NA prophylaxis. An expert panel reviewed the data and categorised the risk of HBVr associated with each class of drugs into low (<1%), intermediate (1-10%), and high (>10%). Our search uncovered 59 studies, including 3,424 HBsAg+ and 5,799 HBsAg-/anti-HBc+ patients, which met our eligibility criteria. Based on medium-high quality evidence, immune checkpoint inhibitors, tyrosine kinase inhibitors, cytokine inhibitors, chimeric antigen receptor T-cell immunotherapies, and corticosteroids were associated with high HBVr risk in HBsAg+ patients; cytokine inhibitors, chimeric antigen receptor T-cell immunotherapies, and corticosteroids with intermediate risk in HBsAg-/anti-HBc+ patients; and anti-tumour necrosis factor agents and immune checkpoint inhibitors with low risk in HBsAg-/anti-HBc+ patients. Provisional recommendations are provided for drugs with low quality evidence. NA prophylaxis is recommended when using drugs associated with a high HBVr risk, while monitoring with on-demand NAs is recommended for low-risk drugs - either approach may be appropriate for intermediate-risk drugs. Consensus on definitions and methods of reporting HBVr, along with inclusion of HBsAg+, and HBsAg-/anti-HBc+ patients in clinical trials, will be key to gathering reliable data on the risk of HBVr associated with immunosuppressive or immunomodulatory therapies.

Should We Treat Immune Tolerant Chronic Hepatitis B? Lessons from Asia

BACKGROUND

Chronic hepatitis B (CHB) remains a public health burden, with more than 257 million persons living with hepatitis B virus globally. Despite the availability of a safe and efficacious vaccine, access to immunization remains poor. As per current estimates, if Asian countries rely only on immunization to reduce the burden of disease, the timelines for HBV elimination will be extended to 2060-2090, a far cry from the World Health Organization's clarion call for viral hepatitis elimination by 2030.

METHODS

Currently, all practice guidelines lay stress on immunization, prevention of mother-to-child transmission and treatment of immune active disease or cirrhosis. In this review, we critically examine the data from the Asian cohorts, clinical and public health rationale of early treatment, risk of HCC, and assess the need for revision of guidelines.

DISCUSSION

Patients in the immune tolerant phase (IT) remain untreated till they meet variable age, transaminase, or fibrosis criteria, are often lost to follow up and continue transmitting the infection. With global migration patterns, immunization programmes alone cannot prevent the complications of HBV like cirrhosis, end-stage liver disease, and hepatocellular carcinoma (HCC). In addition, data from Asian cohorts from Taiwan and Korea suggest that HBV DNA levels are directly associated with increased risk of HCC. Histological evidence of advanced fibrosis or immune reactive T cell subsets in the IT phase also raises doubts about the viability of current guidelines that focus on age, alanine transaminase levels, and liver stiffness as markers of risk of inflammation and fibrosis. Current practice does not take into account the histological subsets with minimal inflammation, HBV genome integration or risk of HCC with high viral loads.

CONCLUSION

New data from Asian cohorts argue the case of expanding access to care to IT-CHB from public health and clinical perspective.

Prevention of hepatitis B reactivation in patients requiring chemotherapy and immunosuppressive therapy

Hepatitis B virus (HBV) reactivation can lead to severe acute hepatic failure and death in patients with HBV infection. HBV reactivation (HBVr) most commonly develops in patients undergoing cancer chemotherapy, especially B cell-depleting agent therapy such as rituximab and ofatumumab for hematological or solid organ malignancies and that receiving hematopoietic stem cell transplantation without antiviral prophylaxis. In addition, the potential consequences of HBVr is particularly a concern when patients are exposed to either immunosuppressive or biologic therapies for the management of rheumatologic diseases, inflammatory bowel disease and dermatologic diseases. Thus, screening with HBV serological markers and prophylactic or pre-emptive antiviral treatment with nucleos(t)ide analogues should be considered in these patients to diminish the risk of HBVr. This review discusses the clinical manifestation, prognosis and management of HBVr, risk stratifications of cancer chemotherapy and immunosuppressive therapy and international guideline recommendations for the prevention of HBVr in patients with HBV infection and resolved hepatitis B.

Management of hepatitis B virus infection in patients with inflammatory bowel disease under immunosuppressive treatment

Hepatitis B remains a significant global clinical problem, despite the implementation of safe and effective vaccination programs. The prevalence of hepatitis B virus (HBV) in patients with inflammatory bowel disease (IBD) largely follows the regional epidemiologic status. Serological screening with hepatitis B surface antigen (HBsAg), and antibodies to hepatitis B surface (anti-HBs) and core (anti-HBc) proteins is a key element in the management of IBD patients and, ideally, should be performed at IBD diagnosis. Stratification of individual cases should be done according to the serologic profile and the IBD-specific treatment, with particular emphasis in patients receiving immunosuppressive regimens. In patients who have not contracted HBV, vaccination is indicated to accomplish protective immunity. Vaccination in immunosuppressed patients, however, is a challenging issue and several strategies for primary and revaccination have been proposed. The risk of HBV reactivation in patients with IBD should be considered in both HBsAg-positive and HBsAg-negative/anti-HBc-positive patients, when immunosuppressive therapies are administered. HBV reactivation is preventable via the administration of prophylactic nucleot(s)ide analogues and should be the standard approach in HBsAg-positive patients. HBsAg-negative/anti-HBc-positive patients represent a non-homogeneous group and bear a significantly lower risk of HBV reactivation. Biochemical, serological and molecular monitoring is currently the recommended approach for anti-HBc patients. Acute HBV infection is rarely reported in IBD patients. In the present review, we outline the problems associated with HBV infection in patients with IBD and present updated evidence for their management.

HBV Reactivation During the Treatment of Non-Hodgkin Lymphoma and Management Strategies

Hepatitis B virus reactivation (HBV-R), which can lead to HBV-related morbidity and mortality, is a common and well-known complication that occurs during the treatment of non-Hodgkin lymphoma (NHL) patients with current or past exposure to HBV infection. HBV-R is thought to be closely associated with chemotherapeutic or immunosuppressive therapies. However, immunosuppressive agents such as anti-CD20 antibodies (e.g., rituximab and ofatumumab), glucocorticoids, and hematopoietic stem cell transplantation (HSCT) administered to NHL patients during treatment can cause deep immunodepression and place them at high risk of HBV-R. In this review, we explore the current evidence, the guidelines of several national and international organizations, and the recommendations of expert panels relating to the definition, risk factors, screening and monitoring strategies, whether to use prophylaxis or pre-emptive therapy, and the optimal antiviral agent and duration of antiviral therapy for HBV-R.

Management of Hepatitis B Virus Reactivation in Malignant Lymphoma Prior to Immunosuppressive Treatment

Hepatitis B reactivation is a common complication in lymphoma patients under immunosuppressive treatment with potentially serious and life-threating consequences. In this review, we discuss the basis of chronic Hepatitis B virus (HBV) infection, the definition and risk factors for HBV reactivation. We overview the management of HBV reactivation based on virological status and immunosuppressive regimen risk stratification. We also highlight and update information about the HBV reactivation in lymphoma patients under novel agent treatment, including newer monoclonal antibodies, small molecule inhibitors, and even chimeric antigen receptor T-cell immunotherapy.

Management of Hepatitis B Virus in Allogeneic Hematopoietic Stem Cell Transplantation

The high morbidity of HBV reactivation following allogeneic hematopoietic stem cell transplantation (allo-HSCT) is partially due to the intense immunologic potency of complex therapeutic regimens, the use of antithymocyte globulin and calcineurin inhibitors to prevent graft versus-host disease (GVHD), prolonged immune reconstitution, and hematological malignancies infected with hepatitis B virus (HBV). Immunosuppression results in the reactivation of HBV replication from covalently closed circular DNA (cccDNA) residing in hepatocytes. However, the role of viral mutations during HBV reactivation needs to be validated. All individuals scheduled to receive allo-HSCT or wish to donate stem cells should be screened for hepatitis B surface antigen (HBsAg), antibodies to hepatitis B core (anti-HBc), and HBV-DNA. HBsAg-positive recipients of allo-HSCT have a high risk of HBV reactivation; thus, they should receive prophylactic antiviral therapy. The high barrier to resistance nucleos(t)-ide analogs (NAs) seems to be superior to the low barrier agents. Resolved-HBV recipients have a lower risk of HBV reactivation than HBsAg-positive recipients. Although prophylactic antiviral therapy remains controversial, regular monitoring of alanine transaminase (ALT) and HBV-DNA combined with preemptive antiviral treatment may be an optimized strategy. However, optimal antiviral therapy duration and time intervals for monitoring remain to be established. Accepting stem cells from HBsAg-positive donors is associated with a risk of developing HBV-related hepatitis. The overall intervention strategy, including donors and recipients, may decrease the risk of HBV-related hepatitis following HSCT from HBsAg positive stem cells. In this review, we summarize the issues of HBV in allo-HSCT, including HBV reactivation mechanism, HBsAg-positive recipients, HBV-resolved infection recipients, and donor-related factors, and discuss their significance.

INASL-ISN Joint Position Statements on Management of Patients with Simultaneous Liver and Kidney Disease

Renal dysfunction is very common among patients with chronic liver disease, and concomitant liver disease can occur among patients with chronic kidney disease. The spectrum of clinical presentation and underlying etiology is wide when concomitant kidney and liver disease occur in the same patient. Management of these patients with dual onslaught is challenging and requires a team approach of hepatologists and nephrologists. No recent guidelines exist on algorithmic approach toward diagnosis and management of these challenging patients. The Indian National Association for Study of Liver (INASL) in association with Indian Society of Nephrology (ISN) endeavored to develop joint guidelines on diagnosis and management of patients who have simultaneous liver and kidney disease. For generating these guidelines, an INASL-ISN Taskforce was constituted, which had members from both the societies. The taskforce first identified contentious issues on various aspects of simultaneous liver and kidney diseases, which were allotted to individual members of the taskforce who reviewed them in detail. A round-table meeting of the Taskforce was held on 20-21 October 2018 at New Delhi to discuss, debate, and finalize the consensus statements. The evidence and recommendations in these guidelines have been graded according to the Grading of Recommendations Assessment Development and Evaluation (GRADE) system with minor modifications. The strength of recommendations (strong and weak) thus reflects the quality (grade) of underlying evidence (I, II, III). We present here the INASL-ISN Joint Position Statements on Management of Patients with Simultaneous Liver and Kidney Disease.

Hepatitis B Virus Reactivation: What Is the Issue, and How Should It Be Managed?

Hepatitis B virus (HBV) reactivation, in the background of cleared and overt chronic HBV infection, can be seen in patients receiving immunosuppressive agents. Risk of reactivation is variably associated with HBV serologic status and types of immunosuppressive therapy. Prevention of HBV reactivation by antiviral prophylaxis is an effective strategy to reduce morbidity and mortality in those with immunocompromised states. This article defines HBV reactivation, discusses risk stratification and common medications that can induce HBV reactivation as well as guideline recommendations for prevention of HBV reactivation, and describes the prognosis and management of patients who experience HBV reactivation.

A comprehensive review of vaccination in patients with inflammatory bowel diseases: An Indian perspective

The disease burden of inflammatory bowel diseases (IBD) in India is estimated to be one of the highest in the world in the near future. Patients with IBD, particularly those on immunosuppressive therapy, are at increased risk for developing vaccine-preventable illnesses. Adult vaccination policy and vaccination in patients with IBD are presently being at a very low level in India. This review discusses in detail the need for vaccination, levels of immunosuppression, a brief account of live and inactivated vaccines, available vaccines, and their utility in patients with IBD, with a special focus on recent recommendations.

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.

2019 Update of Indian National Association for Study of the Liver Consensus on Prevention, Diagnosis, and Management of Hepatocellular Carcinoma in India: The Puri II Recommendations

Hepatocellular carcinoma (HCC) is one of the major causes of morbidity, mortality, and healthcare expenditure in patients with chronic liver disease in India. The Indian National Association for Study of the Liver (INASL) had published its first guidelines on diagnosis and management of HCC (The Puri Recommendations) in 2014, and these guidelines were very well received by the healthcare community involved in diagnosis and management of HCC in India and neighboring countries. However, since 2014, many new developments have taken place in the field of HCC diagnosis and management, hence INASL endeavored to update its 2014 consensus guidelines. A new Task Force on HCC was constituted that reviewed the previous guidelines as well as the recent developments in various aspects of HCC that needed to be incorporated in the new guidelines. A 2-day round table discussion was held on 5th and 6th May 2018 at Puri, Odisha, to discuss, debate, and finalize the revised consensus statements. Each statement of the guideline was graded according to the Grading of Recommendations Assessment Development and Evaluation system with minor modifications. We present here the 2019 Update of INASL Consensus on Prevention, Diagnosis, and Management of Hepatocellular Carcinoma in India: The Puri-2 Recommendations.

Entecavir is Safe and Effective in Long Term for the Treatment of Hepatitis B in Immunocompromised Children

OBJECTIVE

Hepatitis B infection is common in patients with cancer, and prompt treatment is necessary; otherwise, it can result in life-threatening complications. The objective of this study was to assess the long-term safety and efficacy of entecavir in immunocompromised children with hepatitis B.

METHODS

This single-center prospective study was conducted on children with different malignancies referred to our department with evidence of hepatitis B infection. Only those children were included in the study who had HBsAg positive and alanine aminotransferase (ALT) more than 2 times the upper limit of normal and whose hepatitis B virus (HBV) DNA was more than 20,000IU/ml. These children were put on entecavir and prospectively observed upto 192 weeks. Primary efficacy end point was the proportion of patients who achieved undetectable HBV DNA at 48 weeks of treatment. Other efficacy end points were the proportion of patients with HBeAg seroconversion, undetectable HBV DNA, and ALT normalization at weeks 48 and 96 weeks.

RESULTS

A total of 41 children met the inclusion criteria, of which 5 children died because of malignancy and 5 were lost to follow-up. Mean log DNA was 7.67 at the start which after starting entecavir reduced to 4.1, 2.8, 1.19, 1.09, and 0.84 at 12, 24, 48, 72, and 96 weeks, respectively (P value < 0.0001). Mean ALT decreased from 332.5 which reduced to 190, 115, 63, and 46 at 4, 12, 24, and 48 weeks, respectively (P < 0.0001). 67.7% achieved the primary outcome and had undetectable DNA at 48 weeks which increased to 26 (83.9%) at 96 weeks. At 48 weeks, 80.6% patients achieved ALT normalization. Thirty percent developed HBeAg seroconversion. Two patients developed virological breakthrough, one at 96 weeks and another at 192 weeks. No significant adverse effects were observed.

CONCLUSION

Entecavir is safe and effective in long term for the treatment of hepatitis B in immunocompromised children.

Clinical Profile and Efficacy of Antivirals in Hepatitis B Virus Reactivation, in Patients With Cancer Receiving Chemotherapy

BACKGROUND/PURPOSE

Hepatitis B virus reactivation (HBVR) is common in patients withcancer. The aim of the present study was to find out clinical profile of patients with cancer receiving chemotherapy with HBVR and to study the efficacy of entecavir (ETV) and tenofovir in the treatment of HBVR.

METHODS

This is a prospective study in which all consecutive patients with cancer with evidence of HBVR were included. HBVR was defined as: New onset transaminitis with alanine aminotransferase (ALT) >3 times upper limit of normal and >10 fold increase in HBV DNA levels from baseline levels or detection of HBV DNA ≥100,000 IU/ml in patients with no baseline HBV DNA. Patients with HBVR were put on ETV or tenofovir and were closely monitored for efficacy and safety for minimum of 1 year.

RESULTS

Of 204 Hepatitis B surface antigen (HBsAg)-positive patients with different cancers, 92 met the inclusion criteria. Of 92, 46 received ETV 0.5 mg/day and 46 received tenofovir disoproxil fumarate (TDF) 300 mg/day. At 6 months, there was 4.7 log reduction in HBV DNA level in the ETV group and 5.2 log reduction in the TDF group (P = 0.029). Proportion of patients with undetectable HBV DNA (75.7% vs 87.5%), ALT normalization (89.2% Vs 87.5%), HBsAg negativity (25% vs 28.1%), and seroconversion (2.8% vs 3.1%) at 1 year were almost similar in both groups with P value > 0.05 for all efficacy end points. There was no HBVR-related mortality in any group.

CONCLUSION

Both ETV and tenofovir are very effective in the treatment of HBVR and reduce the liver-related mortality and morbidity in such patients.

An expert review on the use of tenofovir alafenamide for the treatment of chronic hepatitis B virus infection in Asia

Asia has intermediate-to-high prevalence and high morbidity of hepatitis B virus (HBV) infection. The use of guideline-recommended nucleos(t)ide analogs with high barrier to resistance, such as entecavir (ETV), tenofovir disoproxil fumarate (TDF), and tenofovir alafenamide (TAF), is one of the key interventions for curbing HBV infection and associated morbidity in Asia. However, there are some challenges to the use of ETV and TDF; while ETV is associated with high resistance in lamivudine (LAM)-exposed (especially LAM-refractory) patients; bone and renal safety issues are a major concern with TDF. Hence, a panel of twenty-eight expert hepatologists from Asia convened, reviewed the literature, and developed the current expert opinion-based review article for the use of TAF in the resource-constrained settings in Asia. This article provides a comprehensive review of two large, phase 3, double-blind, randomized controlled trials of TAF versus TDF in HBeAg-negative (study 0108) and HBeAg-positive (study 0110) chronic HBV patients (> 70% Asians). These studies revealed as follows: (1) non-inferiority for the proportion of patients who had HBV DNA < 29 IU/mL; (2) significantly high rate of normalization of alanine aminotransferase levels; (3) no incidence of resistance; and (4) significantly better bone and renal safety, with TAF vs. TDF up to 144 weeks. Considering the benefits of TAF, the expert panel proposed recommendations for optimizing the use of TAF in Asia, along with guidance on specific patient groups at risk of renal or bone disease suitable for TAF therapy. The guidance provided in this article may help clinicians optimize the use of TAF in Asia.

Reactivation of Hepatitis B Virus in Patients with Multiple Myeloma

Reactivation of hepatitis B virus (HBV) is a well-known complication in patients with hematological malignancies during or after cytotoxic chemotherapy. If the initiation of antiviral therapy is delayed in patients with HBV reactivation, these patients can develop severe hepatitis and may die of fulminant hepatitis. The preventive strategy for HBV reactivation in patients with malignant lymphoma has already been established based on some prospective studies. As there was an increased number of novel agents being approved for the treatment of multiple myeloma (MM), the number of reported cases of HBV reactivation among MM patients has gradually increased. We conducted a Japanese nationwide retrospective study and revealed that HBV reactivation in MM patients is not rare and that autologous stem cell transplantation is a significant risk factor. In this study, around 20% of all patients with HBV reactivation developed HBV reactivation after 2 years from the initiation of therapy, unlike malignant lymphoma. This might be due to the fact that almost all of the patients received chemotherapy for a long duration. Therefore, a new strategy for the prevention of HBV reactivation in MM patients is required.

HBV Reactivation in Patients Undergoing Hematopoietic Stem Cell Transplantation: A Narrative Review

HBV reactivation (HBVr) can occur due to the ability of HBV to remain latent in the liver as covalently closed circular DNA and by the capacity of HBV to alter the immune system of the infected individuals. HBVr can occur in patients undergoing hematopoietic stem cell transplantation (HSCT) with a clinical spectrum that ranges from asymptomatic infection to fulminant hepatic failure. The risk of HBVr is determined by a complex interplay between host immunity, virus factors, and immunosuppression related to HSCT. All individuals who undergo HSCT should be screened for HBV. HSCT patients positive for HBsAg and also those HBcAb-positive/HBsAg-negative are at high risk of HBV reactivation (HBVr) due to profound and prolonged immunosuppression. Antiviral prophylaxis prevents HBVr, decreases HBVr-related morbidity and mortality in patients with chronic or previous HBV. The optimal duration of antiviral prophylaxis remains to be elucidated. The vaccination of HBV-naïve recipients and their donors against HBV prior to HSCT has an important role in the prevention of acquired HBV infection. This narrative review provides a comprehensive update on the current concepts, risk factors, molecular mechanisms, prevention, and management of HBVr in HSCT.