Hepatitis B virus immunization with an adjuvant containing vaccine after liver transplantation for hepatitis B-related disease: failure of humoral and cellular immune response

2020 position statement and recommendations of the European Liver and Intestine Transplantation Association (ELITA): management of hepatitis B virus-related infection before and after liver transplantation

BACKGROUND

Prophylaxis of HBV recurrence is critical after liver transplantation in HBV patients. Despite new prophylactic schemes, most European LT centres persist on a conservative approach combining hepatitis B immunoglobulin (HBIG) and nucleos(t)ides analogues (NA).

AIM

This setting prompted the European Liver Intestine Transplantation Association (ELITA) to look for a consensus on the prevention of HBV recurrence.

METHODS

Based on a 4-round Delphi process, ELITA investigated 16 research questions and established 50 recommendations.

RESULTS

Prophylaxis should be driven according to 3 simplified risk groups: Low and high virological risk patients, with undetectable and detectable HBV DNA pre-LT, respectively, and special populations (HDV, HCC, poorly adherent patients). In low-risk patients, short-term (4 weeks) combination of third-generation NA+ HBIG, or third generation NA monotherapy can be considered as prophylactic options. In high-risk patients, HBIG can be discontinued once HBV DNA undetectable. Combined therapy for 1 year is advised. HBV-HCC patients should be treated according to their virological risk. In HDV/HBV patients, indefinite dual prophylaxis remains the gold standard. Full withdrawal of HBV prophylaxis following or not HBV vaccination should only be attempted in the setting of clinical trials. Organs from HBsAg+ve donors may be considered after assessment of risks, benefits, and patient consent. They should not be used if HDV is present. In poorly adherent patients, dual long-term prophylaxis is recommended. Budget impact analysis should be taken into account to drive prophylactic regimen.

CONCLUSIONS

These ELITA recommendations should stimulate a more rational and homogeneous approach to HBV prophylaxis across LT programs.

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 Vaccination in Patients Receiving Oral Antiviral Therapy Without Hepatitis B Immunoglobulin After Liver Transplant

Our study aimed to determine if a double-dose pre-S containing hepatitis B virus (HBV) vaccination (Sci-B-Vac) could elicit an adequate and sustainable immune response in HBV patients who developed spontaneous hepatitis B surface antibody (anti-HBs) response after liver transplant.

PATIENTS AND METHODS

All patients who received transplants for HBV-related disease for >1 year with normal graft function and hepatitis B surface antigen seronegativity were evaluated. They received a 40-μg HBV vaccine if they were responders in our previous vaccine trial, if anti-HBs was positive for >1 year after liver transplant (LT), or if a peak anti-HBs at any time point after LT was >100 mIU/mL. Primary endpoint was the development of anti-HBs ≥ 10 mIU/mL from previous negative value or a 1-log increase from baseline.

RESULTS

A total of 86 patients were recruited; 5 were responders from a previous trial; 45 patients had detectable anti-HBs >1 year after LT, and 36 patients had an anti-HBs >100 mIU/mL. All (5/5, 100%) previous responders responded to booster vaccination. For the remaining 81 patients, 10 of 81 (12.3%) responded.

CONCLUSION

All previous responders responded to booster vaccination, implying durability and memory of HBV immune response, which is an important prerequisite for definitive host immunity for HBV. In patients who had spontaneous anti-HBs production after LT, a single vaccination can induce response in 12.3% of patients.

The detection of (total and ccc) HBV DNA in liver transplant recipients with hepatitis B vaccine against HBV reinfection

To investigate the levels of hepatitis B virus total DNA (HBV DNA) and covalently closed circular (ccc) DNA in liver transplant recipients who received hepatitis B vaccination, including responders and non-responders, following liver transplantation due to hepatitis B-related diseases and to investigate the efficacy of hepatitis B immune reconstitution against HBV reinfection. Twenty responders and 34 non-responders were enrolled in the present study. The levels of HBV total DNA and ccc DNA in peripheral blood mononuclear cells (PBMCs) and the liver and plasma were detected by real-time polymerase chain reaction (PCR). Fifty-three blood samples and 38 liver allograft tissues were acquired. For the responders, the mean serum titer for anti-HBs (antibodies against hepatitis B surface antigen) was 289 (46.64-1000) IU/ml. Also for the responders, HBV total DNA was detected in PBMCs for one recipient and in the liver for another recipient, but ccc DNA was not detected in either of those 2 recipients. For the non-responders, HBV total DNA was detected in PBMCS for 2 recipients, neither of whom had ccc DNA. Also for the non-responders, HBV total DNA was detected in the livers of 3 recipients, 2 of whom also had ccc DNA. All responders had discontinued hepatitis B immunoglobulin (HBIG), and 13 responders had discontinued antiviral agents. One responder experienced HBV recurrence during the follow-up period. For the majority of liver transplant recipients, no HBV total DNA or ccc DNA was detected in the blood or liver. The lack of HBV total DNA and ccc DNA both in PBMCs and the liver in liver transplant recipients who received hepatitis B vaccination to prevent HBV reinfection should be a prerequisite for the withdrawal of HBIG and/or antiviral agents.

Compounds of the sphingomyelin-ceramide-glycosphingolipid pathways as secondary messenger molecules: new targets for novel therapies for fatty liver disease and insulin resistance

The compounds of sphingomyelin-ceramide-glycosphingolipid pathways have been studied as potential secondary messenger molecules in various systems, along with liver function and insulin resistance. Secondary messenger molecules act directly or indirectly to affect cell organelles and intercellular interactions. Their potential role in the pathogenesis of steatohepatitis and diabetes has been suggested. Data samples collected from patients with Gaucher's disease, who had high levels of glucocerebroside, support a role for compounds from these pathways as a messenger molecules in the pathogenesis of fatty liver disease and diabetes. The present review summarizes some of the recent data on the role of glycosphingolipid molecules as messenger molecules in various physiological and pathological conditions, more specifically including insulin resistance and fatty liver disease.

Long-term efficacy of hepatitis B vaccination as post-transplant prophylaxis in hepatitis B surface antigen (HBsAg) positive recipients and HBsAg negative recipients of anti-hepatitis B core positive grafts

AIM

Hepatitis B virus (HBV) reactivation after liver transplantation in HBV patients, or in HBV negative recipients of anti-hepatitis B core (HBc) positive grafts, has been prevented by prophylactic use of hepatitis B immunoglobulin (HBIG) and/or nucleoside/nucleotide analogs (NA). Vaccination against HBV is an alternative that may provide a chance to discontinue prophylaxis by producing anti-hepatitis B surface (HBs) antibodies.

METHODS

We retrospectively reviewed 40 HBV positive recipients (HBV+ group) and 27 HBV negative recipients of anti-HBc positive grafts (HBV-/anti-HBc+ graft group), who were administrated double-dose hepatitis B vaccination. Recipients were regarded as responders when anti-HBs greater than 100 IU/L was maintained for 6 months or more without HBIG. Response rates of vaccine and long-term outcomes were analyzed.

RESULTS

Eighteen of the 40 patients in the HBV+ group (45%) and 18 of the 27 patients in the HBV-/anti-HBc+ graft group (67%) responded to vaccination after a median of four and three times, respectively. Younger age was the only independent factor associated with vaccine response in the HBV-/anti-HBc+ graft group (P = 0.03), whereas no factor was found to be an independent predictor for vaccine response in the HBV+ group. Among the 18 responders in the HBV+ group, 17 remained without NA or HBIG 8.2 years after the start of vaccination. Ten of those required periodic booster vaccination. All 18 responders in the HBV-/anti-HBc+ graft group remained free from HBV prophylaxis 6.2 years after the start of vaccination.

CONCLUSION

Younger recipients have a greater chance to develop sufficient anti-HBs after double-dose HBV vaccination, leading to discontinue HBV prophylaxis.

One-year extended, monthly vaccination prophylaxis combined with hepatitis B immune globulin for hepatitis B after liver transplantation

AIM

The feasibility of vaccination in liver transplant recipients is highly controversial, and the present study aimed to investigate the efficacy of a 1-year extended, monthly vaccine prophylaxis protocol of a second-generation recombinant vaccine for transplant recipients.

METHODS

The recombinant hepatitis B vaccine (10 µg) was administrated s.c. every month for 12 months as the vaccination protocol to 39 liver transplant recipients in stable condition, including those with hepatitis B-related chronic liver disease (n = 30), those with acute hepatitis B liver failure (hepatitis B surface antibody [HBsAb], n = 4), and those with hepatitis B core antibody positive grafts (n = 5). A fixed dose of hepatitis B immune globulin (HBIG) was administrated during the study based on the monoprophylaxis approach, and the increase in the hepatitis B surface antibody titer was measured to evaluate the efficacy of the vaccination.

RESULTS

The vaccination protocol was initiated a mean of 54 months (range, 13-124) after liver transplantation, and all patients tolerated the vaccination well without adverse effects. The overall hepatitis B virus (HBV) recurrence rate was 5% (2/39) based on hepatitis B surface antigen positivity, and 2% (1/39) based on HBV DNA detectability. Six (15%) patients showed a good response to vaccination with an increase in the HBsAb titer greater than 100 IU/L at the end of vaccination, but only three (8%) maintained an adequate HBsAb level to spare HBIG during the 2-year observation period.

CONCLUSION

While a few patients demonstrated an adequate response to vaccination, the clinical indication for the HBV vaccination for liver transplant recipients is currently minimal.

Prophylactic managements of hepatitis B viral infection in liver transplantation

Liver transplantation (LT) is a considerably effective treatment for patients with end-stage hepatitis B virus (HBV)-related liver disease. However, HBV infection often recurs after LT without prophylaxis. Since the 1990s, the treatment for preventing HBV reinfection after LT has greatly progressed with the introduction of hepatitis B immunoglobulin (HBIG) and nucleos(t)ide analogues (NAs), resulting in improved patient survival. The combination therapy consisting of high-dose HBIG and lamivudine is highly efficacious for preventing the recurrence of HBV infection after LT and became the standard prophylaxis for HBV recurrence. However, mainly due to the high cost of HBIG treatment, an alternative protocol for reducing the dose and duration of HBIG has been evaluated. Currently, combination therapy using low-dose HBIG and NAs is considered as the most efficacious and cost-effective prophylaxis for post-LT HBV reinfection. Recently, NA monotherapy and withdrawal of HBIG from combination therapy, along with the development of new, potent high genetic barrier NAs, have provided promising efficacy, especially for low-risk recipients. This review summarizes the prophylactic protocol and their efficacy including prophylaxis of de novo HBV infection from anti-HBc antibody-positive donors. In addition, challenging approaches such as discontinuation of all prophylaxis and active immunity through hepatitis B vaccination are discussed.

Suppression of Hepatocellular Carcinoma by Inhibition of Overexpressed Ornithine Aminotransferase

Hepatocellular carcinoma is the second leading cause of cancer death worldwide. DNA microarray analysis identified the ornithine aminotransferase (OAT) gene as a prominent gene overexpressed in hepatocellular carcinoma (HCC) from Psammomys obesus. In vitro studies demonstrated inactivation of OAT by gabaculine (1), a neurotoxic natural product, which suppressed in vitro proliferation of two HCC cell lines. Alpha-fetoprotein (AFP) secretion, a biomarker for HCC, was suppressed by gabaculine in both cell lines, but not significantly. Because of the active site similarity between GABA aminotransferase (GABA-AT) and OAT, a library of 24 GABA-AT inhibitors was screened to identify a more selective inhibitor of OAT. (1S,3S)-3-Amino-4-(hexafluoropropan-2-ylidene)cyclopentane-1-carboxylic acid (2) was found to be an inactivator of OAT that only weakly inhibits GABA-AT, l-aspartate aminotransferase, and l-alanine aminotransferase. In vitro administration of 2 significantly suppressed AFP secretion in both Hep3B and HepG2 HCC cells; in vivo, 2 significantly suppressed AFP serum levels and tumor growth in HCC-harboring mice, even at 0.1 mg/kg. Overexpression of the OAT gene in HCC and the ability to block the growth of HCC by OAT inhibitors support the role of OAT as a potential therapeutic target to inhibit HCC growth. This is the first demonstration of suppression of HCC by an OAT inactivator.

Molecular Mechanisms to Control Post-Transplantation Hepatitis B Recurrence

Hepatitis B often progresses to decompensated liver cirrhosis requiring orthotopic liver transplantation (OLT). Although newer nucleos(t)ide analogues result in >90% viral and hepatitis activity control, severely decompensated patients still need OLT because of drug-resistant virus, acute exacerbation, or hepatocellular carcinoma. Acute hepatitis B is also an indication for OLT, because it can progress to fatal acute liver failure. After OLT, the hepatitis B recurrence rate is >80% without prevention, while >90% of transplant recipients are clinically controlled with combined hepatitis B immunoglobulin (HBIG) and nucleos(t)ide analogue treatment. However, long-term HBIG administration is associated with several unresolved issues, including limited availability and extremely high cost; therefore, several treatment protocols with low-dose HBIG, combined with nucleos(t)ide analogues, have been investigated. Another approach is to induce self-producing anti-hepatitis B virus (HBV) antibodies using an HBV envelope (HBs) antigen vaccine. Patients who are not HBV carriers, such as those with acutely infected liver failure, are good candidates for vaccination. For chronic HBV carrier liver cirrhosis patients, a successful vaccine response can only be achieved in selected patients, such as those treated with experimentally reduced immunosuppression protocols. The present protocol for post-OLT HBV control and the future prospects of newer treatment strategies are reviewed.

Management of chronic hepatitis B before and after liver transplantation

Liver transplantation remains the only curative option for eligible patients with complications of chronic hepatitis B (CHB) infection, including severe acute hepatitis flares, decompensated cirrhosis, and hepatocellular carcinoma. In general, all patients with CHB awaiting liver transplantation should be treated with oral nucleos(t)ide analogs (NAs) with high barriers to resistance to prevent potential flares of hepatitis and reduce disease progression. After liver transplantation, lifelong antiviral therapy is also required to prevent graft hepatitis, which may lead to subsequent graft loss. Although combination therapy using NA and hepatitis B immune globulin (HBIG) has been the regimen most widely adopted for over a decade, recent studies have demonstrated that newer NAs with low rates of resistance are effective in preventing graft hepatitis even without the use of HBIG, achieving excellent long term outcome. For patients without pre-existing resistant mutations, monotherapy with a single NA has been shown to be effective. For those with resistant strains, a combination of nucleoside analog and nucleotide analog should be used. To date, clinical trials using therapeutic vaccination have shown suboptimal response, as CHB patients likely have an immune deficit against HBV epitopes. Future strategies include targeting different sites of the hepatitis B replication cycle and restoring the host immunity response to facilitate complete viral eradication.

Travel advice for the immunocompromised traveler: prophylaxis, vaccination, and other preventive measures

Immunocompromised patients are traveling at increasing rates. Physicians caring for these complex patients must be knowledgeable in pretravel consultation and recognize when referral to an infectious disease specialist is warranted. This article outlines disease prevention associated with international travel for adults with human immunodeficiency virus, asplenia, solid organ and hematopoietic transplantation, and other immunosuppressed states. While rates of infection may not differ significantly between healthy and immunocompromised travelers, the latter are at greater risk for severe disease. A thorough assessment of these risks can ensure safe and healthy travel. The travel practitioners' goal should be to provide comprehensive risk information and recommend appropriate vaccinations or prevention measures tailored to each patient's condition. In some instances, live vaccines and prophylactic medications may be contraindicated.

Safe and cost-effective control of post-transplantation recurrence of hepatitis B

A combination of hepatitis B immunoglobulin (HBIG) and nucleoside/nucleotide analogs (NUC) is the current standard of care for controlling hepatitis B recurrence after orthotopic liver transplantation (OLT). However, long-term HBIG administration is associated with several unresolved issues, including limited availability and extremely high cost, and thus several protocols for treatment with low-dose HBIG combined with NUC or HBIG-free regimens have been developed. This article reviews recent advances in post-OLT hepatitis B virus (HBV) control and future methodological directions. New NUC such as entecavir, tenofovir or lamivudine plus adefovir dipivoxil combinations induce a very low frequency of viral resistance. The withdrawal of HBIG after several months of OLT under new NUC continuation also has permissible effects. Even after HBV reactivation, NUC can usually achieve viral control when viral markers are strictly followed up. Another approach is to induce self-producing anti-HBV antibodies via vaccination with a hepatitis B surface antigen vaccine. However, HBV vaccination is not sufficiently effective in patients to treat liver cirrhosis type B after OLT because immune tolerance to the virus has already continued for several decades. Trials of its safety and cost-effectiveness are required. This review advocates a safe and economical approach to controlling post-OLT HBV recurrence.

Prophylaxis against Recurrence in Liver Transplantation Patients with Hepatitis B Virus: What is New?

Hepatitis B virus (HBV) causes an endemic infection that affects nearly 2 billion patients worldwide. It is one of the leading causes of liver cirrhosis, hepatocellular carcinoma (HCC), and liver transplantation (LT). Recurrence of HBV infection after LT is due to specific HBV-host genome interactions. Although hepatitis B immunoglobulin treatment constituted the backbone of HBV recurrence, use of the nucleoside and nucleotide analogs (especially the ones with a higher genetic barrier to resistance), either alone or in combination, offer us new and powerful options in overcoming this serious issue.

β-glycosphingolipids ameliorated non-alcoholic steatohepatitis in the Psammomys obesus model

Liver steatosis is a common characteristic of obesity and type 2 diabetes, and fatty liver disease is increasingly recognized as a major health burden. Accumulating evidence suggests that β-glycosphingolipids play an important role in insulin sensitivity and thus could affect hepatic steatosis. To determine the effect associated with β-glycosphingolipid-mediated amelioration of liver injury, seven groups of Psammomys obesus on a high-energy diet were studied. Animals were treated with daily injections of β-glucosylceramide, β-lactosylceramide, or a combination of both. β-glycosphingolipids ameliorated the hepatic injury manifested by decreased liver enzymes, liver weight, and hepatic fat, and improved liver histology. Administration of both β-glucosylceramide and β-lactosylceramide also decreased interferon (IFN)-γ serum levels. These effects were associated with improved serum cholesterol and triglyceride levels. These data suggest that β-glycosphingolipids ameliorate liver injury in an animal model of nonalcoholic steatohepatitis.

Hepatitis B core antibody-positive donors in cardiac transplantation: a single-center experience

Hepatitis B virus (HBV) core antibody (HBcAb)-positive donors are increasingly utilized in solid organ transplantation. We report a single center's experience in cardiac transplantation with 18 HBcAb-positive donors. Available follow-up on recipients of cardiac allografts from HBcAb-positive donors, including 2 donors with low-level serum HBV DNA at the time of transplantation, demonstrated no documented donor-derived HBV transmission.

Contradictory immune response in post liver transplantation hepatitis B and C

Hepatitis B and C often progress to decompensated liver cirrhosis requiring orthotopic liver transplantation (OLT). After OLT, hepatitis B recurrence is clinically controlled with a combination of hepatitis B immunoglobulin (HBIG) and nucleos(t)ide analogues. Another approach is to induce self-producing anti-hepatitis B virus (HBV) antibodies using a HBV envelope antigen vaccine. Patients who had not been HBV carriers such as acutely infected liver failure or who received liver from HBV self-limited donor are good candidate. For chronic HBV carrier patients, a successful response can only be achieved in selected patients such as those treated with experimentally reduced immunosuppression protocols or received an anti-HBV adaptive memory carrying donor liver. Hepatitis C virus (HCV) reinfects transplanted livers at a rate of >90%. HCV reinfected patients show different severities of hepatitis, from mild and slowly progressing to severe and rapidly progressing, possibly resulting from different adaptive immune responses. More than half the patients require interferon treatment, although the success rate is low and carries risks for leukocytopenia and rejection. Managing the immune response has an important role in controlling recurrent hepatitis C. This study aimed to review the adaptive immune response in post-OLT hepatitis B and C.

Prevention of recurrent hepatitis B infection after liver transplantation

BACKGROUND

Recurrence of hepatitis B virus (HBV) infection after liver transplantation can lead to graft loss and a reduction in long-term survival. The purpose of this review is to summarize the current therapeutic options for preventing HBV recurrence in liver transplant recipients.

DATA SOURCES

Up to January 2013, studies that were published in MEDLINE and EMBASE on prevention of HBV recurrence after liver transplantation were reviewed.

RESULTS

There have been remarkable advancements in the past two decades on the prevention of HBV recurrence after liver transplantation, from the discovery of hepatitis B immune globulin (HBIG) and lamivudine monotherapy to the combination therapy using HBIG and lamivudine. With the development of newer and stronger antiviral agents, the need for life-long HBIG is doubtful. With their low resistance profile, oral antiviral prophylaxis using these new agents alone is sufficient and is associated with excellent outcome.

CONCLUSIONS

Restoration of host HBV immunity with adoptive immunity transfer and vaccination may represent the ultimate strategy to withdraw prophylactic treatment and to achieve a drug free regimen against HBV recurrence after liver transplantation.

Which patients respond best to hepatitis B vaccination after a hepatitis B virus-related liver transplantation?

BACKGROUND

A combination of hepatitis B immunoglobulin and nucleos(t)ide analogues is the current standard of care for controlling hepatitis B recurrence after orthotopic liver transplantation (OLT). However, frequent immunoglobulin treatment is expensive and inconvenient. This study investigated the efficacy of hepatitis B virus (HBV) vaccination in preventing the recurrence of hepatitis B after living donor OLT.

METHODS

Twenty-seven patients who had undergone living donor OLT participated in the study; five had acute HBV infected liver failure (ALF-OLT) and 22 had HBV related liver cirrhosis (LC-OLT). Hepatitis B surface antigen (HBsAg)-containing vaccine was administered to them for at least 1 year after transplantation and continued once monthly for up to 36 months post-OLT. Patients who had anti-HBs antibody titers above 100 mIU/mL for a minimum of 6 months without immunoglobulin administration were defined as good responders; the others were defined as poor responders. Interferon-γ enzyme-linked immunospot assays against HBs and HBc antigens were used to assay cellular immune responses.

RESULTS

All five of the ALF-OLT patients had good responses after a median of four (range 2.5-5) vaccinations. Nine of the 22 LC-OLT patients had good responses after a median of 19 (range 11.5-30) vaccinations. Among the LC-OLT group, those with livers donated by relatively higher-aged, marital and high-titer anti-HBs antibody donors were good responders. LC-OLT patients classed as good responders showed interferon-γ responses comparable to those of the ALF-OLT patients.

CONCLUSIONS

The ALF-OLT and LC-OLT patients who received livers from relatively higher-aged, marital, high-titer anti-HBs antibody donors were the best candidates for HBV vaccine administration. Boosting donors before transplantation may facilitate later vaccine response of the recipients.

Immunoprophylaxis against and prevention of recurrent viral hepatitis after liver transplantation

The reinfection of the hepatic allograft with hepatitis B virus and hepatitis C virus can have important sequelae that result in poor long-term patient and graft survival. Although a response to treatment with antiviral medications can improve these outcomes, not all patients tolerate these medications or experience viral eradication. Avoiding reinfection of the graft is the most effective means of improving the long-term outcomes for these patient populations. This review is focused on the prevention of viral hepatitis reinfection after liver transplantation.

One-year vaccination against hepatitis B virus with a MPL-vaccine in liver transplant patients for HBV-related cirrhosis

Conflicting results have been reported on vaccination against hepatitis B virus (HBV) as a prophylaxis against viral recurrence after liver transplantation. We investigated the efficacy of 1-year, monthly vaccination using an adjuvant 3-deacylated monophosphoryl-lipid-A (MPL) recombinant S vaccine initially administered together with hepatitis B immunoglobulins (HBIg) in 18 patients transplanted for HBV-related cirrhosis. All received 12 vaccine doses (HBsAg, 20 mcg plus MPL, 50 mcg): the initial six doses (phase I) were administered within 7days after intravenous HBIg (2000IU), while the last 6 (phase II) following HBIg withdrawal. All patients received lamivudine during the study. Anti-HBs titers were determined before each dose and then for 1year after vaccination. After phase I anti-HBs titers were greater than 100IU/l in all patients and in three (16.6%) were greater than 500IU/l. After phase II 10 patients (55.5%) achieved anti-HBs titers greater than 100IU/l and five (27.7%) greater than 500IU/l. One year after vaccination eight patients (44.4%) maintained anti-HBs titers greater than 100IU/l, with a median titer of 234IU/l (102-1205), and 2 (11.1%) greater than 500IU/l. One-year extended monthly vaccination with a MPL-adjuvant recombinant vaccine induces a sustained protective anti-HBs response in approximately half of transplant recipients.

Hepatitis B immunoglobulins and/or lamivudine for preventing hepatitis B recurrence after liver transplantation: a systematic review

BACKGROUND

Currently, hepatitis B immunoglobulins (HBIg) and/or lamivudine have become the main options for prevention of hepatitis B recurrence after liver transplantation.

AIM

To assess the benefits of HBIg and/or lamivudine for prevention of hepatitis B recurrence after liver transplantation.

METHODS

We conducted a search of electronic databases and a manual search of bibliographical lists of relevant articles. All randomized clinical trials and non-randomized studies that meet the pre-specified criteria were included. However, results of non-randomized studies were reported under 'exploratory analyses' in the result section. The outcome measure was hepatitis B recurrence.

RESULTS

Two randomized and 44 non-randomized studies were included. Meta-analysis of two randomized studies shows one week HBIg combined with lamivudine regimen had equivalent effect compared with long-term high-dose HBIg regimen for preventing hepatitis B recurrence (RR 1.23; 95% CI 0.38-4.03; P = 0.73). For 44 non-randomized studies, only qualitative systematic review was performed. With long-term HBIg prophylaxis, hepatitis B recurrence rate ranged from 3.7% to 65%; with lamivudine prophylaxis, hepatitis B recurrence rate varied from 3.8% to 40.4%; Long-term high-dose HBIg plus lamivudine prophylaxis can reduce the risk of HBV recurrence to less than 10%.

CONCLUSIONS

Long-term HBIg prophylaxis or lamivudine prophylaxis can reduce the risk for hepatitis B virus recurrence. Long-term high-dose HBIg combined with lamivudine can further reduce HBV recurrence to less than 10%.

HBIg discontinuation with maintenance oral anti-viral therapy and HBV vaccination in liver transplant recipients

BACKGROUND

Hepatitis B (HBV) is an uncommon indication for liver transplantation in the US accounting for approximately 5% of cases. Recurrence prophylaxis is typically long-term hepatitis B immune-globulin (HBIg) and an oral anti-HBV agent. Because of high HBIg costs and improving efficacy of new oral agents, there is increasing interest in HBIg discontinuation.

AIM

To describe results of a protocol at our center including HBV vaccination and HBIg discontinuation.

METHODS

All patients received HBIg therapy and an oral anti-viral agent from the time of transplant. Patients transplanted for HBV with a stable post-operative clinical course underwent HBV vaccination and HBIg discontinuation. After HBIg discontinuation, patients were monitored for HBV recurrence for at least one year. Recurrence was defined as either viral (HBV-DNA 10(4) copies/ml on two consecutive occasions) or hepatitis (viral recurrence with elevated liver transaminases).

RESULTS

Of 1182 recipients, 36 (3%) had HBV. Twenty-four were excluded from the protocol, and the remaining 12 patients underwent HBIg withdrawal. Median age at HBIg discontinuation was 56 (range, 36-70) years, median time from transplant to HBIg discontinuation was 62.8 (range, 27.5-128) months, and median time of follow-up after discontinuation was 27.4 (range, 13-69) months. Of the 12 patients vaccinated, no patients maintained HBSAb >or= 10 IU/l at last follow-up. There was no viral or hepatitis recurrence and no deaths or graft loss.

CONCLUSIONS

HBIg discontinuation with maintenance oral anti-viral monotherapy is safe and effective for HBV liver transplant recipients. Vaccination is not effective in this population.

Alpha versus beta: are we on the way to resolve the mystery as to which is the endogenous ligand for natural killer T cells?

Natural killer T (NKT) lymphocytes are a unique subset of cells that play a role in regulating the immune system. For the past decade, studies have focused upon attempts to define these cells and to determine the ligand(s) that are required for their development and peripheral activation. Many research groups have focused upon determining the mechanisms for activating or inhibiting NKT cells in an attempt to control immune-mediated disorders as well as infectious and malignant conditions by using different ligand structures. Alpha-anomeric glycolipids and phospholipids derived from mammalian, bacterial, protozoan and plant species have been suggested as potential ligands for these lymphocytes. Some of these ligands were structured in forms that can bind to CD1d molecules. The lack of alpha-anomeric glycosphingolipids in mammals and the modest effect of these ligands in human studies, along with recent data from animal models and humans on the NKT-dependent immunomodulatory effect of beta-glycosphingolipids, suggest that the beta-anomeric ligands have the potential to be the endogenous NKT ligand.

Glucocerebroside: an evolutionary advantage for patients with Gaucher disease and a new immunomodulatory agent

Gaucher disease (GD) is caused by the reduced activity of a lysosomal enzyme, glucocerebrosidase, leading to the accumulation of glucocerebroside (GC). The relatively high prevalence of this disease within an ethnic group is believed to reflect a selective advantage. Treatment with enzyme replacement therapy (ERT) is safe and effective in ameliorating the primary symptoms of the disease, yet there have been reports that some patients on ERT have developed type 2 diabetes or metabolic syndrome, malignancies and central nervous system disorders. A series of animal studies suggest that these complications may be related to the reduction of GC levels by the enzyme administered. GC has been shown to have an immunomodulatory effect through the promotion of dendritic cells, natural killer T cells, and regulatory T cells. The break down of GC to ceramide can underline part of these findings. Clinical trials suggested a beneficial effect of GC in type 2 diabetes or nonalcoholic steatohepatitis. This review of the data from animal models and humans proposes that the increased level of GC may provide an evolutionary advantage for patients with GD. Indirectly, these data support treating symptomatic patients with mild/moderate GD with low-dose ERT and re-evaluating the use of ERT in asymptomatic patients.

Current prophylactic strategies against hepatitis B virus recurrence after liver transplantation

Prophylactic strategies against hepatitis B virus (HBV) recurrence after liver transplantation (LT) are essential for patients with HBV-related disease. Before LT, lamivudine (LAM) was proposed to be down-graded from first- to second-line therapy. In contrast, adefovir dipivoxil (ADV) has been approved not only as first-line therapy but also as rescue therapy for patients with LAM resistance. Furthermore, combination of ADV and LAM may result in lower risk of ADV resistance than ADV monotherapy. Other new drugs such as entecavir, telbivudine and tenofovir, are probably candidates for the treatment of hepatitis-B-surface-antigen-positive patients awaiting LT. After LT, low-dose intramuscular hepatitis B immunoglobulin (HBIG), in combination with LAM, has been regarded as the most cost-effective regimen for the prevention of post-transplant HBV recurrence in recipients without pretransplant LAM resistance and rapidly accepted in many transplant centers. With the introduction of new antiviral drugs, new hepatitis B vaccine and its new adjuvants, post-transplant HBIG-free therapeutic regimens with new oral antiviral drug combinations or active HBV vaccination combined with adjuvants will be promising, particularly in those patients with low risk of HBV recurrence.

Hepatitis B vaccination: The key towards elimination and eradication of hepatitis B

Hepatitis B virus infection is a global health problem. Worldwide, about 360 million people are chronically infected with the virus. They continue to spread the virus to others and are themselves at risk of chronic liver diseases and hepatocellular carcinoma. The infection can now be treated by antivirals or interferons and the transmission route can be interrupted. Nevertheless, the most effective means is to immunize all susceptible individuals, especially young children, with safe and efficacious vaccines. The combined efforts of vaccination, effective treatment and interruption of transmission make elimination of the infection plausible and may eventually lead to eradication of the virus. Because hepatitis B vaccination has a key role in the control of hepatitis B, properties of this vaccine, its effectiveness in pre-exposure and post-exposure settings, duration of protection after vaccination and the need of booster doses are discussed. Mass hepatitis B vaccination in children decreases the carriage of the virus, and the diseases associated with acute and chronic infection, including hepatocellular carcinoma. Challenges that need to be solved to expand mass vaccination, and the strategies towards elimination and eventual eradication of hepatitis B in the world are also discussed.

Successful hepatitis B vaccination in liver transplant recipients with donor-specific hyporesponsiveness

Currently, patients are prescribed lifelong treatment with hepatitis B immunoglobulin (HBIg) after liver transplantation (LT) for hepatitis B virus (HBV)-related diseases in order to prevent reinfection with HBV. Active immunization with an HBV vaccine would be a preferable alternative; however, the immunosuppressive environment in LT recipients is believed to elicit a poor response to vaccination. Minimizing the exposure of the HBV-infected LT recipients to immunosuppressants would be beneficial in inducing adaptive immunity against HBV by vaccination. In this study, in addition to efforts to minimize immunosuppression, prophylaxis with HBV vaccination combined with continuous HBIg administration was performed in 17 LT recipients who had undergone transplantation attributable to HBV-related diseases. During the observation period, the overall response rate to HBV vaccination was 64.7%. The immune status of the recipients was evaluated by a mixed lymphocyte reaction assay in response to allostimulation. Patients showing a donor-specific hyporesponse with a well-maintained response to the third-party stimulus always achieved a sustained immune response to the vaccine, whereas patients showing a hyporesponse to both the donor and the third-party stimulus were unable to do so. Thus, inducing an anti-donor-specific immunosuppressive status by minimizing immunosuppression should enable post-transplant HBV vaccination to be a promising prophylactic strategy.

Hepatitis B virus vaccine switch program for prevention of de novo hepatitis B virus infection in pediatric patients

The principal objective of this study was to evaluate the feasibility of Hepatitis B virus (HBV) vaccine switch program after 1-year Hepatitis B immunoglobulin (HBIG) for the prevention of de novo HBV (DNHBV) infection in pediatric recipients of hepatitis B core antibody (anti-HBc)-positive grafts. In this study, we enrolled pediatric recipients (n = 14), who had undergone living donor liver transplantation with anti-HBc-positive grafts between July 2000 and July 2005 and were followed up for over 24 months after transplantation. HBIG was given daily during the first week and intermittently in order to maintain anti-hepatitis B surface antigen (anti-HBs) titers greater than 200 IU/l until 12 months post-transplantation. Then the HBV vaccine was given intermittently as a substitute for HBIG when anti-HBs titer fell below 200 IU/l. The median follow-up duration after vaccination was 26.5 months, and a median of 2.03 doses of vaccine per year was required for the maintenance of anti-HBs titers greater than at least 100 IU/l. Two of the patients did not start the HBV vaccine due to sustained high anti-HBs titer. Eleven completed the HBV switch, whereas 1 was ongoing. With the HBV vaccine switch program, anti-HBs titers greater than 100 IU/l could be maintained conveniently and effectively.