Prophylaxis for Hepatitis B Virus Reactivation after Allogeneic Stem Cell Transplantation in the Era of Drug Resistance and Newer Antivirals: A Systematic Review and Meta-Analysis

Use of Hepatitis B Virus-Positive Organs in Organ Transplantation

The significant morbidity and mortality of people with end-stage renal, liver, heart, and lung diseases in need of transplantation provides rationale for use of organs from donors who are hepatitis B positive. The recipient's hepatitis B status plays a key role in defining the prophylactic strategy. The availability of safe and effective therapies (hepatitis B antivirals and hepatitis B immune globulin) has contributed to the safety of using hepatitis B-positive donors. The outcomes in both liver and nonliver solid organ transplant recipients given hepatitis B-positive organs have been excellent if appropriate prophylactic therapies provided.

Hepatitis B virus among hematopoietic stem cell transplant recipients: Antiviral impact in seroconversion, engraftment, and mortality in a Latin American center

BACKGROUND

Hepatitis B virus (HBV) infection is a worldwide concern with a broad distribution. In immunosuppressed populations, such as solid organ and hematopoietic stem cell transplant (HSCT) recipients, it can reactivate leading to acute hepatic failure. Different risk factors are known for higher rates of reactivation, and entecavir, tenofovir, and lamivudine are often used for prophylaxis and treatment. However, data regarding the impact of antiviral drugs in neutrophil and platelet engraftment are still unknown and concern the management of viral hepatitis post-HSCT.

METHODS

We performed a single-center, retrospective, observational study reviewing medical records of patients referred for hematopoietic stem cell transplant from 2010 to 2017, which were also HBV infected, aiming to describe outcomes related to antiviral treatment and also the impact on platelet and neutrophil recovery after transplant. A secondary goal consisted of analyzing the impact of HBV infection in early and late mortality post-HSCT. The study included patients with positive blood bank screening for hepatitis B infection (HBsAg, Anti-HBc or HBV-NAT), confirmed later on by a laboratory routine serology.

RESULTS

A total of 1132 hematopoietic stem cell recipients were assessed between 2010 and 2017. Eighty-six patients were confirmed to have HBV infection, of which six were HBsAg-positive, 20 were isolated anti-HBc-positive, and 60 had resolved infection (anti-HBc-positive and anti-HBs-positive). With regard to prophylaxis, 19 patients underwent HSCT on HBV antiviral therapy or prophylaxis: two were HBeAg-positive, three were HBeAg-negative and HBV-DNA was only detectable in three of them. Moreover, one patient had an occult HBV infection. Regarding therapy, 9 patients were on entecavir, 6 patients on lamivudine, two on tenofovir, and two of them on a combination of tenofovir + lamivudine due to HIV co-infection. Reverse seroconversion was not identified in any patients receiving antiviral therapy or prophylaxis, but it was detected in one patient with occult hepatitis B and another with resolved infection. No severe side effects led to therapy discontinuation in the treated group, which also did not have any significant delay in neutrophil or platelet engraftment when compared to patients without antiviral therapy. In addition, the only factors associated with increased mortality were transplant onset after 50 years, allogeneic transplant and myeloablative conditioning regimens. Interestingly, the presence of HBsAg or detectable HBV-DNA was not related to worse outcomes, neither the use of rituximab. In multivariate analysis, the use of antiviral therapy, the occurrence of graft-versus-host disease or CMV reactivation also was not linked to increased mortality.

CONCLUSIONS

To sum up, HBV serology, ALT, and HBV-DNA monitoring are essential to detect hepatic flares earlier, even in populations with chronic inactive hepatitis, due to the possibility of later seroconversion. HBV infection was not related to increased 2-year mortality post-transplant. Antiviral prophylaxis did not cause any important clinical or laboratory side effects that could demand discontinuation, and its use was not associated with later neutrophil and platelet engraftments.

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.

Prophylaxis of hepatitis B virus (HBV) infection reactivation - recommendations of the Working Group for prevention of HBV reactivation

Hepatitis B virus (HBV) is one of the main causes of chronic liver diseases and hepatocellular carcinoma. After infection the majority of HBV-infected patients achieve immune control leading to HBV-DNA stabilization at a low level. The risk of HBV reactivation rises significantly when HBV-infected patients receive immunosuppressive treatments. Presented recommendations provide guidelines for management of patients scheduled or undergoing therapies, which through their immunomodulatory activity contribute to the impairment of antiviral immunity, including chemotherapy, immunosuppressive treatment or biological therapy.