Management of hepatitis B virus infection after liver transplantation

Hyperimmune Globulins for the Management of Infectious Diseases

This review is focused on the use of hyperimmune globulin therapy to treat some infectious diseases of viral or bacterial origin. Despite the introduction of antibiotics and vaccines, plasma immunoglobulin therapy from whole blood donation can still play a key role. These treatments provide passive transfer of high-titer antibodies that either reduces the risk or the severity of the infection and offer immediate but short-term protection against specific diseases. Antibody preparations derived from immunized human donors are commonly used for the prophylaxis and treatment of rabies, hepatitis A and B viruses, varicella-zoster virus, and pneumonia caused by respiratory syncytial virus, Clostridium tetani, Clostridium botulinum. The use of hyperimmune globulin therapy is a promising challenge, especially for the treatment of emerging viral infections for which there are no specific therapies or licensed vaccines.

Advancements in the prevention of hepatitis B recurrence by nucleos(t)ide analogue monotherapies after liver transplantation

Previous studies have shown that the recurrence rate of HBV (hepatitis B virus) after liver transplantation (LT) can be as high as 80% without any preventive measures. Therefore, prevention of HBV recurrence after LT is always an essential part of clinical work worldwide. The NAs that have been approved for HBV treatment include lamivudine, adefovir dipivoxil, entecavir (ETV), and telbivudine, tenofovir disoproxil fumarate (TDF), and tenofovir alafenamide (TAF). They are often combined with HBIG to prevent HBV recurrence after LT clinically. However, NAs with a higher genetic barrier, such as ETV, TDF, and TAF, can improve liver function by strongly inhibiting HBV replication and reducing the risks of HBV resistance. Recently, some NAs with a higher genetic barrier, such as ETV, TDF, and TAF, have been adopted as monotherapy for preventing the recurrence of hepatitis B after LT in multiple organ transplant centres and have achieved effective outcomes. This article aims to review the advances for NAs monotherapy in prophylaxis for HBV recurrence after LT.

Present and future management of viral hepatitis

Viral hepatitis can result in important morbidity and mortality, with its impact on health conditioned by the specific type of hepatitis, the geographical region of presentation and the development and access to new drugs, among other factors. Most acute presentation forms are self-limiting and may even go unnoticed, with just a small percentage of cases leading to acute liver failure that may necessitate transplantation or even cause the death of the patient. However, when they become chronic, as in the case of hepatitis B virus and C virus, unless they are diagnosed and treated adequately they may have severe consequences, like cirrhosis or hepatocarcinoma. Understanding of the mechanisms of transmission, the pathogenesis, the presence of vaccinations and the development over recent years of new highly-efficient, potent drugs have meant that we are now faced with a new scenario in the management of viral hepatitis, particularly hepatitis B virus and hepatitis C virus. The spectacular advances in hepatitis C virus treatment have led the World Health Organization to propose the objective of its eradication by 2030. The key aspect to achieving this goal is to ensure that these treatments reach all the more vulnerable population groups, in whom the different types of viral hepatitis have a high prevalence and constitute a niche that may perpetuate infection and hinder its eradication. Accordingly, micro-elimination programs assume special relevance at the present time.

An Overview of the Current Hepatitis B Treatment Strategies after Liver Transplantation

Currently, liver transplantation (LT) is considered as the only option for the treatment of patients with various causes of liver failure, including patients with chronic hepatitis B virus (HBV) infections. Overall, patients with HBV who undergo LT are at increased risk of hepatitis B infection recurrence. Although the current knowledge regarding the pathophysiology of this infection has been dramatically increased over the past few decades, it is still considered a complex disease process with varying degrees of clinical characteristics and changing patterns over time. There are various treatment strategies for preventing HBV recurrence in the LT setting. Generally, these regimens include oral nucleoside/ nucleotide analogues (NAs), hepatitis B immune globulin (HBIG), and vaccines or the combination of these drugs. The treatment strategy of choice should be based on cost-effectiveness, along with other patients underlying conditions. In this case, studies indicate that potent NAs are more cost-effective than HBIG in most case scenarios. In this article, we aimed to review the general medications used in the prophylaxis of the recurrence of HBV infection after LT.

Early outcomes of implanting larger-sized grafts in deceased donor liver transplantation

BACKGROUND

The outcomes of large-sized graft mismatch in deceased donor liver transplantation (LT) have been rarely studied. The aim of this study was to determine whether a large-sized graft for recipient influenced the post-transplant outcomes.

METHODS

A total of 273 patients undergoing LT were enrolled and divided into a large and a normal-sized graft group by graft weight to recipient weight (GWRW) >2.5% (n = 76) or GWRW ≤2.5% (n = 197). Post-operative complications and outcomes were retrospectively analysed.

RESULTS

The two groups were comparable in demographic characteristics. The rate of complications was significantly higher in the large-sized graft group including early allograft dysfunction (36.8% versus 17.8%, P = 0.001), hepatic necrosis (26.3% versus 13.7%, P = 0.01) and massive hydrothorax (25% versus 14.7%, P = 0.04). The large-sized graft group suffered higher early mortality compared with the normal-sized graft group (30 days: 14.5% versus 5.6%, P = 0.02, 90 days: 21.1% versus 9.6%, P = 0.01). The primary causes of early death were multiple organ failure (10.5% versus 2%, P = 0.002) and sepsis (2.6% versus 1.5%, P = 0.54). Four parameters including donor alanine transaminase, GWRW, estimated blood loss and model for end-stage liver disease score were significant on multivariate analysis, and indicated significant risk factors for the early mortality of recipients.

CONCLUSION

In deceased donor LT, GWRW >2.5% is associated with increased liver injury, risk of early mortality and other adverse outcomes. Thus, donor livers should be allocated to recipients with GWRW ≤2.5%.

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.

Screening and Prophylaxis to Prevent Hepatitis B Reactivation: Transplant Recipients

Organ transplantation is a lifesaving procedure for many patients. To prevent rejection or graft-versus-host disease, recipients require long-term immunosuppression. In patients who have ever been exposed to hepatitis B, it is possible for reactivation to occur; this includes patients who are anti-hepatitis B core antibody-positive only or both anti-hepatitis B core antibody-positive and hepatitis B surface antibody-positive. The susceptibility to this varies with the nature of the transplant. Hepatitis B can be transmitted from donor to recipient. It is important to assess the hepatitis B status and formulate a strategy to prevent transmission and prevent reactivation.

Role of nucleoside/nucleotide analogues and low-dose hepatitis B immune globülin in prophylaxis of hepatitis B recurrence among cadaveric liver transplant recipients

BACKGROUND/AIMS

Hepatitis B core antibody (HBcAb) positivity of the donor or the recipient may pose a risk of hepatitis B virus (HBV) reactivation following liver transplantation (LT). We retrospectively investigated patient survival and reactivation among recipients who were given low-dose Hepatitis B Immune Globulin (HBIG) plus antiviral agent (AV) versus AV only.

MATERIALS AND METHODS

Records of cadaveric LT recipients, between 2013 and 2016, with positive Hepatitis B surface Antigen (HBsAg) and/or HBcAb and recipients who had received LT from HBcAb-positive donors were reviewed. Patient characteristics and clinical data were extracted. Donor variables were retrieved from the United Network of Organ Sharing (UNOS) database. HBIG (1560 IU/mL) Intravenous (IV) was intraoperatively administered with three daily doses. Entecavir 1 mg daily was also given. STATA was used for statistical analysis.

RESULTS

There were 53 recipients; 39 (73.6%) were male with a median age of 59 y. HCV was the major indication in 30 (55.6%) patients. There were 28 recipients (52.8%) who received HBIG plus AV and 25 (47.2%) received AV only. The Model of End Stage Liver Disease (MELD) score between the groups were similar. Survival rates at 6, 12, and 24 months were 100% (n=53), 93.2% (n=44), and 100.0% (n=26), respectively. There was no reactivation; two recipients in the AV group and one in the HBIG plus AV group died within 12 months.

CONCLUSION

This study supports the use of low-dose HBIG and AV for post-LT prophylaxis to be as effective as conventionally used high-dose HBIG (9600 IU) plus AV. Future prospective larger studies are warranted to examine the potential benefits of using AV alone without HBIG.

Current clinical evidence for nucleos(t)ide analogues in patients with HBV-related hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a leading cause of death globally and is frequently seen following Hepatitis B virus (HBV) or Hepatitis C virus infection. Areas with high HBV infection rates, such as Asia and sub-Saharan Africa, are therefore also high-risk areas for HCC. Areas covered: This review identifies and discusses the current evidence from robust clinical trials which have investigated the benefits of Nucleos(t)ide analogue (NA) antiviral therapy in HBV-related HCC patients, including HCC patients that underwent liver transplantation and HCC patients with or without curative treatment. In addition, we assess how this evidence has influenced current clinical practice, with a particular focus on those areas of high HBV infection rates. Expert commentary: A number of studies have assessed whether NA antiviral treatment can improve the prognosis of HBV-related HCC patients. In this review we evaluate the current evidence, including that from trials in Asia, for antiviral NA treatments in HBV-related HCC patients. We also focus on those NAs with a high genetic barrier to resistance (i.e. ETV or TDF), on different therapeutic approaches, and on the future evidence that is required in this field.

Recommendations for the treatment of hepatitis B in 2017

The therapeutic goal which is currently unfrequent but realistic in HBV infected patients is sustained HBsAg clearance. It is preceded by the loss or significant suppression of HBV replication and leads to inhibition of the progression of liver fibrosis, normalization of biochemical indicators of liver damage, reduction in the risk of hepatocellular carcinoma, prolongation of survival, prevention of HBV infection in the transplanted organ in post-transplant patients, enhancement of the quality of life, inhibition or reversal of extrahepatic changes associated with HBV infection, and halting of the spread of HBV infections. Recommendations of Polish Group of Experts for HBV for 2017 provide guidelines to assess treatment eligibility, choice of the first-line drug, monitoring and duration of treatment, management of treatment failure as well as therapy of HBV associated cirrhosis or hepatocellular carcinoma. Moreover it contains advice for treatment of HBV infection in children, females planning pregnancy or pregnant. We also included recommendations for pre- and post-exposure prophylaxis, prevention of HBV transmission from mother to infant, after liver transplantation, on immunosuppressive therapy and during HCV treatment.

Hepatitis B immunity in the pediatric liver transplant population

PURPOSE OF REVIEW

Hepatitis B virus (HBV) infection contributes significantly to vaccine-preventable disease related deaths, and insufficient HBV immunity may have unique implications for the pediatric liver transplant population. This article reviews the significance of HBV infection and the vaccination and screening measures needed to achieve adequate HBV immunity in these children.

RECENT FINDINGS

HBV non-immunity among transplant candidates is higher than expected, even after appropriate completion of the vaccine series. Annual measurement of quantifiable HBV surface antibody in this vulnerable group should guide administration of booster and/or re-vaccination, improving immunoprotection from this potentially deadly hepatotropic virus. The liver plays a vital role in immune regulation; it induces immune tolerance and competence and both clears antigens from the circulation and generates liver-primed memory cells through antigen presentation via hepatic scavenger cells. Lymphocyte populations are depleted in patients with liver disease.

SUMMARY

Immunity provided during early childhood against HBV infection is important to both pediatric liver transplant candidates and aging recipients. Appropriate vaccination and achievement of adequate immunity pre-transplant and post-transplant is critical. The field of pediatric transplantation is ripe for functional cellular and humoral immunity studies that examine factors which predict poor immune response to childhood vaccines, particularly HBV.