Long-term safety and efficacy of tenofovir disoproxil fumarate substitution for hepatitis B immunoglobulin following liver transplantation

Asian Pacific Association for the Study of the Liver clinical practice guidelines on liver transplantation

Liver transplantation is a highly complex and challenging field of clinical practice. Although it was originally developed in western countries, it has been further advanced in Asian countries through the use of living donor liver transplantation. This method of transplantation is the only available option in many countries in the Asia-Pacific region due to the lack of deceased organ donation. As a result of this clinical situation, there is a growing need for guidelines that are specific to the Asia-Pacific region. These guidelines provide comprehensive recommendations for evidence-based management throughout the entire process of liver transplantation, covering both deceased and living donor liver transplantation. In addition, the development of these guidelines has been a collaborative effort between medical professionals from various countries in the region. This has allowed for the inclusion of diverse perspectives and experiences, leading to a more comprehensive and effective set of guidelines.

Hepatitis B immunoglobulin inhibits the secretion of HBV via antigen-antibody precipitation in the multivesicular body

BACKGROUND AND AIMS

Although the main action of human hepatitis B immunoglobulin (HBIG) is to neutralize hepatitis B virus surface antigen (HBsAg) in serum, HBIG is known to be localized in the cell. However, the effect of intracellularly located HBIG is poorly understood because of the low purity of conventional plasma-derived HBIG (cHBIG). We attempted to elucidate the mechanism of action of internalized HBIG using recombinant HBIG (lenvervimab).

METHODS

We used HBsAg producing cell lines, non-HBsAg cell lines and human HBsAg-producing hepatocytes. The autophagosome lysis pathway-related proteins Rab5, calnexin, giantin, and Rab7 were used to localize HBsAg and anti-HBs-IgG in the cytoplasm using Western blotting and confocal microscopy.

RESULTS

Intracellular anti-HBs-IgG (lenvervimab and cHBIG) transported via Fc receptor-mediated endocytosis increased the number of autophagosomes. However, there was no change in autolysis. HBsAg and anti-HBs-IgG co-localized in the multivesicular body and precipitated in the cytoplasm. HBsAg secretion into culture medium decreased after lenvervimab treatment. Simultaneously, the amount of cellular HBsAg increased in the cell lines but decreased in human hepatocytes. Furthermore, intracellular lenvervimab is not easily removed from HBsAg cell lines.

CONCLUSIONS

Lenvervimab decreases HBsAg secretion, and HBsAg antibody precipitation in the multivesicular body may play an important role.

Antiviral prophylaxis against hepatitis B recurrence after liver transplantation: Current concepts

The advance in treatment against hepatitis B virus (HBV) infection with the development of nucleos(t)ide analogues (NAs) with high genetic barrier to resistance, including entecavir and tenofovir, has improved clinical outcomes of patients transplanted for HBV infection, by preventing HBV recurrence after liver transplantation (LT) effectively. Currently, after LT, the combination of hepatitis B immunoglobulin (HBIG) and a high-barrier NA is considered as the standard of care for prophylaxis against HBV recurrence. However, because of the high cost of intravenous high-dose HBIG, other routes of HBIG administration, such as intramuscular or subcutaneous, have come to the foreground. In addition, several transplant centres tend to use a NA as monoprophylaxis, following a short post-LT period of HBIG and NA combination. Lately, studies using HBIG-free prophylactic regimens with entecavir or tenofovir have shown promising outcomes in preventing HBV recurrence, mostly regarding patients with undetectable HBV DNA at the time of LT. Although vaccination against HBV has been an attractive prophylactic approach, its efficacy has been controversial. Moreover, further studies are needed regarding long-term outcomes of complete withdrawal anti-HBV prophylaxis. For patients transplanted for HBV/HDV co-infection, combined regimen should be administered for a longer period post-LT. Finally, the use of grafts from hepatitis B core antibody-positive donors is safe for HBV-negative recipients, with the administration of lifelong antiviral prophylaxis.

Prevention and treatment of new hepatitis B after living donor liver transplantation in children

BACKGROUND

This study aimed to explore the prevention and treatment of new hepatitis B in children after liver transplantation with livers positive for HBcAg and to examine the treatment of new hepatitis B.

METHODS

A total of 22 children who received livers positive for HBcAg between January 2013 and December 2015 were retrospectively analyzed. After their operations, the children were given lamivudine for anti-hepatitis B virus (HBV) treatment, a hepatitis B vaccine or intermittent supplements of hepatitis B immunoglobulins to prevent recurrence of the infection, and entecavir for anti-hepatitis B treatment. The children were categorized into two groups: one group of children stopped taking lamivudine one year after operation (n=7) by themselves, while the other group did not (n=15).

RESULTS

Of the seven children who stopped lamivudine anti-HBV treatment, six developed hepatitis B at 24.33±13.95 months after operation. Of these children, five were treated with entecavir, resulting in their HBV DNA decreasing to undetectable levels (<50 IU/mL). HBsAg turned negative in four of these patients, but in one patient it did not. The other patient with new hepatitis B continued to use lamivudine, resulting in their HBV DNA decreasing to normal levels (<50 IU/mL) but without their HBsAg turning negative. No new cases of hepatitis B were found in the 15 children who did not stop anti-HBV treatment.

CONCLUSIONS

The long-term prophylactic therapy of nucleoside analogues combined with hepatitis B immunoglobulins should be used for a long time after liver transplantation with a liver positive for HBcAg. Discontinuation of nucleoside analogues is associated with a higher risk of the new onset of hepatitis B. Entecavir has a significant effect on the treatment of postoperative new hepatitis B in children.

Prevention of HBV Recurrence after Liver Transplant: A Review

Globally, hepatitis B virus (HBV) infection is recognized as a major risk factor for the development of hepatocellular carcinoma, and HBV-induced liver failure is one of the leading indications for liver transplantation. Until about two decades ago, liver transplantation in patients with chronic HBV infection was a relative contraindication, due to high risk of viral replication with the use of immunosuppressants which could result in graft infection. In the 1990s, hepatitis B immunoglobulin (HBIg) use significantly reduced the risk of graft infection, improving outcomes of liver transplant in patients with chronic HBV infection. However, very high costs, especially with the need for long-term use, became a major concern. With the advent of nucleos(t)ide analogs (NAs), there was less need for high-dose, long-term HBIg use to prevent HBV recurrence. Lamivudine was initially used but resistance soon became a major issue. This was followed by more potent NAs, such as entecavir and tenofovir, emerging as the more preferred agents. Additionally, the use of these antiviral agents (HBIg and/or NAs) have made it possible to use the grafts from donors with positivity for hepatitis B core antibody, allowing for expansion of the donor pool. Nevertheless, there is no consensus on management protocols, which vary significantly amongst centers. In this review, we appraise studies on management strategies used and the role of active vaccination in the prevention of HBV recurrence in post-liver transplant patients.

Hepatitis B Immunoglobulin discontinuation in long-term liver transplant patients

BACKGROUND

Hepatitis B immunoglobulin (HBIG)-as a monotherapy or combined with nucleos(t)ide analogs (NUCs)-has effectively lowered Hepatitis B virus (HBV) reinfection after liver transplantation. However, it is associated with high costs and viral resistance. HBIG-free prophylaxis with novel NUCs (tenofovir, entecavir) composes a viable alternative. We evaluated reinfection rate, histological changes, and outcome associated with HBIG discontinuation.

METHODS

A retrospective analysis was performed of patients undergoing liver transplantation due to HBV-induced liver disease at our center since 1988. A controlled HBIG discontinuation was conducted between 2015 and 2017 in 65 patients. Recurrent infection was determined by HbsAg values. Fibrosis and inflammation were evaluated by routine biopsy. The survival of patients after HBIG discontinuation was compared to a control population on HBIG for prophylaxis.

RESULTS

From 1988 to 2013, 352 patients underwent liver transplantation due to HBV-induced liver disease. 169 patients could be included for analysis. 104 (51.5%) patients continued a prophylaxis containing HBIG. HBIG was discontinued in 65 (38.5%) patients in a controlled manner, maintaining an oral NUC. None of those patients showed HBV reinfection or graft dysfunction. No significant changes of inflammation grades (P = .067) or fibrosis stages (P = .051) were detected. The survival of patients after HBIG discontinuation was comparable to the control (P = .95).

CONCLUSION

HBIG withdrawal under continuation of oral NUC therapy is safe and not related to graft dysfunction, based on blood tests and histology. HBIG-free prophylaxis is not associated with a worse outcome and displays a financial relief as well as a logistic simplification during long-term follow-up.

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.