High-dose hepatitis B immunoglobulin therapy in hepatocellular carcinoma with hepatitis B virus-DNA/hepatitis B e antigen-positive patients after living donor liver transplantation

β-CATENIN stabilizes HIF2 through lncRNA and inhibits intravenous immunoglobulin immunotherapy

Introduction

Tumor-initiating cells (TICs) are rare, stem-like, and highly malignant. Although intravenous hepatitis B and C immunoglobulins have been used for HBV and HCV neutralization in patients, their tumor-inhibitory effects have not yet been examined. Hepatitis B immunoglobulin (HBIG) therapy is employed to reduce hepatocellular carcinoma (HCC) recurrence in patients after living donor liver transplantations (LDLT).

Hypothesis

We hypothesized that patient-derived intravenous immunoglobulin (IVIG) binding to HCC associated TICs will reduce self-renewal and cell viability driven by β-CATENIN-downstream pathways. β-CATENIN activity protected TICs from IVIG effects.

Methods

The effects of HBIG and HCIG binding to TICs were evaluated for cell viability and self-renewal.

Results

Inhibition of β-CATENIN pathway(s) augmented TIC susceptibility to HBIG- and HCIG-immunotherapy. HBV X protein (HBx) upregulates both β-CATENIN and NANOG expression. The co-expression of constitutively active β-CATENIN with NANOG promotes self-renewal ability and tumor-initiating ability of hepatoblasts. HBIG bound to HBV+ cells led to growth inhibition in a TIC subset that expressed hepatitis B surface antigen. The HBx protein transformed cells through β-CATENIN-inducible lncRNAs EGLN3-AS1 and lnc-β-CatM. Co-expression of constitutively active β-CATENIN with NANOG promoted self-renewal ability of TICs through EGLN3 induction. β-CATENIN-induced lncRNAs stabilized HIF2 to maintain self-renewal of TICs. Targeting of EGLN3-AS1 resulted in destabilization of EZH2-dependent β-CATENIN activity and synergized cell-killing of TICs by HBIG or HCIG immunotherapy.

Discussion

Taken together, WNT and stemness pathways induced HIF2 of TICs via cooperating lncRNAs resulting in resistance to cancer immunotherapy. Therefore, therapeutic use of IVIG may suppress tumor recurrence through inhibition of TICs.

State of the art treatment of hepatitis B virus hepatocellular carcinoma and the role of hepatitis B surface antigen post-liver transplantation and resection

Chronic hepatitis B virus (HBV) infection is the major aetiology of hepatocellular carcinoma (HCC). The optimal goal of therapy, hepatitis B surface antigen (HBsAg) loss and anti-HBs production, is achieved rarely and HBsAg-associated HCC risk is well recognized. Here we review the role of HBsAg in HCC, the link between HBsAg and HCC recurrence post-liver transplantation or resection, and the implications for therapy. HBV-associated carcinogenesis is a multifactorial process. The observation that HBV-related HCC can occur in the absence of cirrhosis is compatible with a direct oncogenic effect of the virus, which may occur via multiple mechanisms, including those mediated by both mutated and unmutated HBsAg. HCC recurrence in HBsAg-positive patients post-liver transplantation has been reported in 10%-15% of patients and is likely to be because of expansion of residual HCC tumour cell populations containing integrated HBV DNA, which expand and independently replicate HBV, leading to the recurrence of both HCC and HBV. The direct role of HBsAg in HCC recurrence post-liver resection is less clear. Cirrhosis is the most important risk factor for HCC development, and precancerous cirrhotic liver remains after resection, with the potential to undergo malignant transformation regardless of the existence of HBV-derived oncogenic drivers. The role of HBsAg in the development of HCC and its recurrence post-surgical intervention has multiple implications for therapy and suggests a potential role for immunotherapy in the future management of HCC, in particular post-liver transplantation. Use of hepatitis B immunoglobulins that target HBsAg directly, alongside immune-oncology therapies, may be relevant in this setting.

Recurrence of Hepatitis B Infection in Liver Transplant Patients Receiving Long-Term Hepatitis B Immunoglobulin Prophylaxis

BACKGROUND Long-term real-world data are relatively sparse regarding recurrence of chronic hepatitis B virus (HBV) infection after liver transplantation using hepatitis B immunoglobulin (HBIg) and nucleos(t)ide analogue (NUC) prophylaxis. MATERIAL AND METHODS Data from 371 adults transplanted for HBV-related disease at 20 European centers and given HBIg for ³12 months ± NUC therapy were analyzed retrospectively. RESULTS HBIg comprised Hepatect® (iv HBIgB; n=299), subcutaneous Zutectra® (sc HBIg, n=236), and other HBIg preparations (n=130); 93.5% received NUC therapy. Mean follow-up was 6.8±3.5 years. The primary efficacy variable, freedom from HBV recurrence, occurred in 95.7% of patients (95% CI [93.1%, 97.5%]). The observed incidence of recurrence was 16/371 (4.3%) (annual rate 0.65%); 5/16 patients with recurrence had discontinued HBIg and 7/16 had anti-HBs <100 IU/l. Excluding these 7 patients, the HBV recurrence rate was 2.4%. The recurrence rate while on HBIg therapy was 1 per 2069 months. In patients who discontinued HBIg, risk of HBV recurrence versus sc HBIg users was increased by 5.2-fold (1 per 1 603 versus 1 per 8379 treatment months). The annual rate of HBV-related hepatocellular carcinoma (HCC) recurrence was 1.7%. CONCLUSIONS These results support the long-term use of HBIg with NUC therapy as an effective management strategy to minimize risk of HBV recurrence and virus-related complications after liver transplantation.

Reactivation of hepatitis B after liver transplantation: Current knowledge, molecular mechanisms and implications in management

Chronic hepatitis B (CHB) is a major global health problem affecting an estimated 350 million people with more than 786000 individuals dying annually due to complications, such as cirrhosis, liver failure and hepatocellular carcinoma (HCC). Liver transplantation (LT) is considered gold standard for treatment of hepatitis B virus (HBV)-related liver failure and HCC. However, post-transplant viral reactivation can be detrimental to allograft function, leading to poor survival. Prophylaxis with high-dose hepatitis B immunoglobulin (HBIG) and anti-viral drugs have achieved remarkable progress in LT by suppressing viral replication and improving long-term survival. The combination of lamivudine (LAM) plus HBIG has been for many years the most widely used. However, life-long HBIG use is both cumbersome and costly, whereas long-term use of LAM results in resistant virus. Recently, in an effort to develop HBIG-free protocols, high potency nucleos(t)ide analogues, such as Entecavir or Tenofovir, have been tried either as monotherapy or in combination with low-dose HBIG with excellent results. Current focus is on novel antiviral targets, especially for covalently closed circular DNA (cccDNA), in an effort to eradicate HBV infection instead of viral suppression. However, there are several other molecular mechanisms through which HBV may reactivate and need equal attention. The purpose of this review is to address post-LT HBV reactivation, its risk factors, underlying molecular mechanisms, and recent advancements and future of anti-viral therapy.

Short Course of Postoperative Hepatitis B Immunoglobulin Plus Antivirals Prevents Reinfection of Liver Transplant Recipients

BACKGROUND

Hepatitis B immune globulin (HBIG) has been an integral component of prophylaxis against hepatitis B virus (HBV) recurrence in liver transplantation (LT) recipients, but HBIG is costly and inconvenient to administer, prompting consideration of alternative regimens.

METHODS

In this retrospective cohort, we report on the success of antiviral therapy combined with a short course (in hospital only) HBIG in liver transplant recipients with HBV DNA less than 100 IU/mL pre-LT.

RESULTS

A total of 42 hepatitis B surface antigen (HBsAg) positive, human immunodeficiency virus and hepatitis D virus-negative patients with pretransplant HBV DNA undetectable to 100 IU/mL who received HBIG 5000 IU in anhepatic phase and daily for 5 days together with nucleos(t)ide analogues indefinitely yielded 1- and 3-year cumulative incidences of recurrence, defined by positive serum HBsAg, of 2.9% (upper 95% confidence interval, 19%). One patient had HBV viremia 16 months post-LT without detectable HBsAg. Both patients with either HBsAg positivity or viremia had recurrent hepatocellular carcinoma diagnosed within a month of detection. Post-LT survival was 98% and 94% at 1 and 5 years, respectively.

CONCLUSIONS

We conclude that a very short course of HBIG combined with long-term antiviral therapy is highly effective in preventing HBV recurrence and should be the preferred strategy for LT recipients with undetectable or low-level viremia at time of LT.