Adoptive donor immunity protects against resolved hepatitis B virus reactivation after allogeneic haematopoietic stem cell transplantation in the world's largest retrospective cohort study

Risk factors of HBV reactivation in leukemia patients with resolved HBV infection after allogeneic hematopoietic stem cell transplantation

BACKGROUND

The hepatitis B surface antigen (HBsAg)-negative and antibody to hepatitis B core antigen (anti-HBc)-positive patients after allogeneic hematopoietic stem cell transplantation (allo-HSCT) are at risk of HBV reactivation (HBVr).

METHODS

To analyze the risk factors for HBVr, a total of 1,042 leukemia patients(≥18years of age), who underwent allo-HSCT from January 2016 to April 2022 in The First Affiliated Hospital of Soochow University, were enrolled in the study. Finally, 193 leukemia patients with resolved HBV infection were included into the study.

RESULTS

HBVr occurred in 22 patients (11.39%), and the median time to HBVr was 24 months (with a range of 11-51months). Hepatitis flares developed in 22.73% of patients with HBVr, and hepatic failure occurred in 1 patient. During the follow-up period, only 1(1.3%) patient experienced HBVr among 79 patients with antiviral prophylaxis. While 21(18.42%) patients experienced HBVr among 114 patients without antiviral prophylaxis. The cumulative incidence of HBV reactivation at 3 years was 44.4.% for anti-HBs-negative donors/recipients with a low anti-HBs titer (<100IU/L) and 7.1% for anti-HBs-positive donors/recipients with a high anti-HBs titer (≥100IU/L) respectively. In addition, univariate and multifactorial Cox regression analyses confirmed the use of rituzumab as a risk factor for HBV reactivation.

CONCLUSION

The univariate and multivariate analysis confirmed that the anti-HBs titer in both recipients and donors are protective indicators to prevent incidence of HBVr. In addition, antiviral prophylaxis can significantly reduce the incidence of HBVr.

The liver in sickle cell disease

Liver involvement in SCD patients is frequent but often misdiagnosed or underestimated, except in case of advanced liver diseases. Because of so far poorly recognized forms of chronic SCD-related vascular injury that can silently evolved towards end stages or facilitate ACLF, any persisting liver function tests abnormalities should be carefully investigated, following the above proposed algorithm. Work up and management must be considered multidisciplinary in relationship with a Hepatologist. Early SCD hepatopathy should prompt revision of SCD management to prevent further liver injury and decompensation, discussing transfusion exchanges and hydro urea when not yet initiated, and control for any cofactor of liver injury. The role of HSCT in early SCD hepatopathies also deserves evaluation. In advanced SCD hepatopathies, liver transplantation, which has been rarely performed so far, is the only therapeutic option associated with improved survival. It should definitely be discussed- either electively in case of decompensation in SCD cirrhosis or jaundice/recurrent cholangitis in cholestatic diseases, with excellent outcome, - or emergently in case of ALF or ACLF with more mitigate results. To improve knowledge and management of SCD liver diseases, creation of national and international registries, as well as longitudinal observational cohorts are encouraged.

Adoptive immune transfer from donors offers Anti-HBV protection to HBsAb-negative patients after Allo-HSCT

Adoptive transfer of hepatitis B virus (HBV) immunity may occur following allogeneic hematopoietic stem cell transplantation (allo-HSCT). Here, we investigated the adoptive transfer of HBV immunity in 112 patients without HBV surface antibody (HBsAb) (HBsAb-) at the time of their first allo-HSCT. After allo-HSCT, HBV-DNA（87.5%） and HBsAg（11.1%%）cleared in HBsAg+ patients. All HBsAg- patients acquired HBsAb immediately. Nevertheless, HBsAb titers subsequently declined, and 39/67 (58.2%) patients lost HBsAb during follow-up. The 5-year overall survival (OS) was better in patients who lost HBsAb. Multivariate analysis showed that the independent risk factors for OS were lack of cytomegalovirus (CMV) clearance, acute graft-versus-host disease (aGVHD), and no HBsAb loss. Overall, adoptive immune transfer offers anti-HBV protection to patients without HBsAb, as they acquire HBsAb and clear HBV-DNA and HBsAg, while HBsAb loss after allo-HSCT predicts better survival.

Predicting the loss of hepatitis B surface antigen following haematopoietic stem cell transplantation in patients with chronic HBV infection

Clearance of hepatitis B surface antigen (HBsAg) is an ideal therapeutic goal for patients with chronic hepatitis B virus (HBV) infection. Haematopoietic stem cell transplantation (HSCT) is the most effective therapy for a variety of haematological diseases. For patients with chronic HBV infection who received allo-HSCT, recipient hepatitis B serological status might change after allo-HSCT; however, data on the loss of HBsAg following allo-HSCT are relatively rare. We first reviewed patients with chronic HBV infection who received allo-HSCT in our centre from 2010 to 2020, and 125 patients were included in our study. A total of 62 patients (49.6%) with chronic HBV infection achieved HBsAg loss after allo-HSCT. Positivity for HBeAb and HBsAb in donors as well as no cytomegalovirus (CMV) infection were identified as independent risk factors for HBsAg loss after allo-HSCT. A predictive model including positivity for HBeAb and HBsAb in donors and no CMV infection was subsequently developed and performed well with effective discrimination and calibration. In addition, patients could benefit when this model is used in the clinic, as revealed via decision-curve analysis (DCA). However, multicentre prospective studies are required for validation.

Hepatitis B Flare in Hepatitis B e Antigen-Negative Patients: A Complicated Cascade of Innate and Adaptive Immune Responses

Chronic hepatitis B virus (HBV) infection is a dynamic process involving interactions among HBV, hepatocytes, and the host immune system. The natural course of chronic hepatitis B (CHB) is divided into four chronological phases, including the hepatitis B e antigen (HBeAg)-positive and HBeAg-negative phases. During HBV flare, alanine aminotransferase (ALT) levels abruptly rise to >5× the upper limit of normal; this is thought to occur due to the immune response against an upsurge in serum HBV DNA and antigen levels. Hepatitis flares may occur spontaneously, during or after antiviral therapy, or upon immunosuppression or chemotherapy in both HBeAg-positive and HBeAg-negative patients. The clinical spectrum of HBV flares varies from asymptomatic to hepatic decompensation or failure. HBeAg seroconversion with ≥ 1 year of consolidation therapy is accepted as an endpoint of oral antiviral therapy in HBeAg-positive patients, but recommendations for treating HBeAg-negative patients differ. Thus, the management of HBeAg-negative patients has attracted increasing interest. In the current review, we summarize various types of HBV flares and the associated complex cascade of innate and adaptive immune responses, with a focus on HBeAg-negative CHB patients. Hopefully, this review will provide insight into immunopathogenesis to improve the management of HBV flares in HBeAg-negative CHB patients.

Hepatitis B Virus Infection in Patients Receiving Allogeneic Hematopoietic Stem Cell Transplantation

Considering a steady increase in the number of allogeneic hematopoietic stem cell transplantations (allo-HSCT) worldwide and the significant proportion of the world’s population that has been exposed to hepatitis B virus (HBV) infection, HBV reactivation following allo-HSCT remains an important issue for post-transplant morbidity and mortality. Antiviral prophylaxis can reduce HBV replication, severity of HBV-related hepatitis, and mortality; therefore, identification of patients at risk is crucial. It is recommended that all recipients and donors should be screened for active or prior HBV infection, including HBsAg, antiHBc, and antiHBs. Adoptive immunity transfer from the donor seems to have protective effects against HBV reactivation. Antiviral prophylaxis should be initiated in all HBsAg-positive patients. HBsAg-negative, antiHBc-positive patients remain at risk; therefore, antiviral prophylaxis should be considered if baseline serum HBV DNA is detectable. In HBsAg-negative, antiHBc-positive patients without detectable HBV DNA, close monitoring of viral load with an on-demand therapy is necessary. Entecavir or tenofovir rather than lamivudine are more appropriate for the emergence of lamivudine resistance. The treatment duration remains unclear, with 6- to 12-month therapy after cessation of immunosuppressive therapy commonly recommended. Here we review the updated evidence and recent recommendations regarding HBV reactivation in patients undergoing allo-HSCT for individualized therapy.

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.

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.