Failure of hepatitis B vaccination in patients receiving lamivudine prophylaxis after liver transplantation for chronic hepatitis B

Viral Infections During Pregnancy: The Big Challenge Threatening Maternal and Fetal Health

Viral infections during pregnancy are associated with adverse pregnancy outcomes, including maternal and fetal mortality, pregnancy loss, premature labor, and congenital anomalies. Mammalian gestation encounters an immunological paradox wherein the placenta balances the tolerance of an allogeneic fetus with protection against pathogens. Viruses cannot easily transmit from mother to fetus due to physical and immunological barriers at the maternal-fetal interface posing a restricted threat to the fetus and newborns. Despite this, the unknown strategies utilized by certain viruses could weaken the placental barrier to trigger severe maternal and fetal health issues especially through vertical transmission, which was not fully understood until now. In this review, we summarize diverse aspects of the major viral infections relevant to pregnancy, including the characteristics of pathogenesis, related maternal-fetal complications, and the underlying molecular and cellular mechanisms of vertical transmission. We highlight the fundamental signatures of complex placental defense mechanisms, which will prepare us to fight the next emerging and re-emerging infectious disease in the pregnancy population.

Efficacy and Safety of Hepatitis B Virus Vaccination Following Hepatitis B Immunoglobulin Withdrawal After Liver Transplantation

BACKGROUND

Hepatitis B immunoglobulin (HBIG) and oral nucleoside/nucleotide analogs have been the mainstay of hepatitis B virus (HBV) prophylaxis after liver transplantation. However, long-term HBIG administration could have disadvantages, such as an increase in medical costs and the development of mutant HBV strains. This study aimed to investigate the safety and efficacy of HBV vaccination after the withdrawal of HBIG after liver transplantation.

METHODS

This prospective open-label single-arm observational clinical trial enrolled 41 patients who underwent liver transplantation between 2010 and 2016 because of a condition related to chronic HBV infection. At the time of enrollment, all patients had taken entecavir and discontinued HBIG administration. When hepatitis B surface antibody titer was undetectable after the withdrawal of HBIG, a recombinant HBV vaccine was injected intramuscularly at month 0, 1, and 6.

RESULTS

After excluding 5 patients who dropped out and 2 patients who had a persistent hepatitis B surface antibody titer, 9 (26.5%) of 34 patients had a positive vaccination response. The median hepatitis B surface antibody titer at seroconversion was 86 (12-1000) IU/L, and those at the end of follow-up were 216 (30-1000) IU/L. No patients experienced HBV recurrence during the study period. Sex (female, odds ratio 32.91 [1.83-592.54], P = .018) and the dosing interval of HBIG before withdrawal (≥90 days, 16.21 [1.21-217.31], P = .035) were independent contributing factors for positive response to the vaccination.

CONCLUSION

HBV vaccination still deserves consideration as active immunoprophylaxis after liver transplantation because it could provide added immunity to nucleoside/nucleotide analogs monotherapy with excellent cost-effectiveness.

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.

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.

Prophylaxis and treatment in liver transplantation. VII Consensus Document of the Spanish Society of Liver Transplantation

Whilst prophylaxis of hepatitis B is universally accepted after liver transplantation (LT), national recommendations for the prophylaxis and treatment of hepatitis B virus (HBV) infection after LT are lacking in Spain. The aim of the VII consensus meeting organised by the Spanish Society of Liver Transplantation (SETH) was to set recommendations on the prophylaxis and treatment of hepatitis B after LT. The scientific evidence and strength of recommendations was evaluated by using the "Grading of Recommendations Assessment, Development and Evaluation" (GRADE) system. This document describes the recommendations and their level of evidence for: the definition and risk factors for hepatitis B recurrence after LT, monitoring and prophylaxis of hepatitis B recurrence at different periods after LT, treatment of hepatitis B before and after LT, and the prophylaxis of HBV infection by the recipients of LT with hepatitis B core antigen positive donors.

Liver transplantation using hepatitis B core positive grafts with antiviral monotherapy prophylaxis

BACKGROUND & AIMS

The impact of hepatitis B core antibody (anti-HBc) positive liver grafts on survival and the risk of de novo hepatitis B virus (HBV) infection after liver transplantation (LT) remain controversial. Therefore, we aimed to analyze this risk and the associated outcomes in a large cohort of patients.

METHODS

This was a retrospective study that included all adults who underwent LT at Queen Mary Hospital, Hong Kong, between 2000 and 2015. Data were retrieved from a prospectively collected database. Antiviral monotherapy prophylaxis was given for patients receiving grafts from anti-HBc positive donors.

RESULTS

A total of 964 LTs were performed during the study period, with 416 (43.2%) anti-HBc positive and 548 (56.8%) anti-HBc negative donors. The median follow-up time was 7.8 years. Perioperative outcomes (hospital mortality, complications, primary nonfunction and delayed graft function) were similar between the 2 groups. The 1-, 5- and 10-year graft survival rates were comparable in anti-HBc positive (93.3%, 85.3% and 76.8%) and anti-HBc negative groups (92.5%, 82.9% and 78.4%, p = 0.944). The 1-, 5- and 10-year patient survival rates in anti-HBc positive group were 94.2%, 87% and 79% and were similar to the anti-HBc negative group (93.5%, 84% and 79.7%, p = 0.712). One-hundred and eight HBsAg negative recipients received anti-HBc positive grafts, of whom 64 received lamivudine and 44 entecavir monotherapy prophylaxis. The risk of de novo HBV was 3/108 (2.8%) and all occurred in the lamivudine era. There were 659 HBsAg-positive patients and 308 (46.7%) received anti-HBc positive grafts. The risk of HBV recurrence was similar between the 2 groups. Donor anti-HBc status did not impact on long-term patient and graft survival, or the risk of hepatocellular carcinoma recurrence after LT.

CONCLUSIONS

De novo HBV was exceedingly rare especially with entecavir prophylaxis. Anti-HBc positive grafts did not impact on perioperative and long-term outcomes after transplant.

LAY SUMMARY

The risk of de novo hepatitis B infection after liver transplantation was rare when using hepatitis B core positive liver grafts with entecavir monotherapy prophylaxis. Hepatitis B core antibody status did not impact on perioperative and long-term outcomes after liver transplantation. This provides support for the clinical use of hepatitis B core positive liver grafts when required.

Antiviral Therapy for AECHB and Severe Hepatitis B (Liver Failure)

This chapter describes the principles of antiviral therapy, treatment strategies, medications and recommendations for AECHB, HBV-ACLF, HBV-related liver cirrhosis, HBV-related HCC, and liver transplantation.

Severe exacerbation of chronic hepatitis B is closely related to continuous HBV replication. Therefore, inhibiting HBV replication to reduce viral load may block disease progression and improve the quality of life of these patients. ETV or TDF has been recommend first-line drug for the treatment of AECHB.

A hyperactive immune response due to continuous HBV replication is the main mechanism for development of severe hepatitis B. In addition to comprehensive treatment, early administration of potent nucleoside analogs can rapidly reduce HBV DNA concentration, relieve immune injury induced by HBV, and reduce liver inflammation and patient mortality. Antiviral agents have become important in the treatment of severe exacerbation of chronic hepatitis B.

Long-term antiviral treatment with nucleoside analogs can delay or reverse the progress of liver cirrhosis. Virologic response, viral resistance and adverse drug reactions should be closely monitored during treatment. The treatment should be optimized for maximum effect based on each patient’s responses.

Effective antiviral therapy can suppress HBV replication and reduce the incidence of HBV-related HCC. Patients with HBV-related HCC should receive individualized and optimal multidisciplinary comprehensive treatment. Anti-viral drugs with high efficacy, low resistance and low adverse drug reactions should be selected to improve the patient’s quality of life and prolong survival time.

Methods to prevent HBV reinfection after liver transplantation include passive immunization (HBIG), antiviral treatment (nucleoside analogs) and active immunization (hepatitis B vaccine).

Clinical trials involving sequential combination therapy with NUC and Peg-IFN have shown statistically significant decline in HBsAg levels on treatment and high rates of sustained post-treatment serologic response. Combination therapy with novel DAA and immunotherapeutic approach may hold promise to overcome both cccDNA persistence and immune escape, representing a critical step towards HBV cure.

Taiwan consensus statement on the management of chronic hepatitis B

The experts of Taiwan Association for the Study of Liver (TASL) have actively participated and led the guidelines on hepatitis B virus (HBV) management by Asian Pacific Association for the Study of Liver (APASL) which is the first international association for the study of liver to publish the statement on HBV management before. However, there are more and more new data on the natural history and treatment of HBV infection in the past decade. These include new application of an old biomarker (quantitative HBsAg), clinical significance of HBV genotype and naturally occurring mutations, the role of non-invasive examination in evaluating severity of hepatic fibrosis, clinical significance of outcome calculators, new drug or new combination strategies towards more effective therapy and organ transplantation including liver and non-liver transplantation. It is time to publish the guidelines on HBV management of Taiwan. Hence, TASL have conducted an expert meeting to review, to discuss and to debate the relevant literatures, followed by draft the manuscript of HBV management guidelines and recommendations. The guidelines include general management, indications for fibrosis assessment, time to start or stop drug therapy, choice of drug to initiate therapy, when and how to monitor the patients during and after stopping drug therapy. Recommendations on the therapy of patients in special circumstances, including women in childbearing age, patients with antiviral drug resistance, concurrent viral infection, hepatic decompensation, patient receiving immune suppression or chemotherapy and patients in the setting of liver transplantation and hepatocellular carcinoma, are also included.

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.

Active immunization in patients transplanted for hepatitis B virus related liver diseases: A prospective study

Introduction

Prophylactic administration of hepatitis B immunoglobulin (HBIG) and nucleos(t)ide analogues (NAs) is the standard treatment for controlling hepatitis B virus (HBV) recurrence after liver transplantation (LT). Since lifelong use of HBIG is expensive and inconvenient and the antibodies level in anti-hepatitis B surface (HBs) is not sustainable and stable, an alternative strategy is to produce anti-HBs antibodies by active immunization. Our present study aimed to prospectively investigate the efficacy and safety of procedural HBV vaccination in transplanted patients.

Methods

Recipients who had undergone LT for hepatitis B related liver diseases more than one year before, with no evidence of HBV recurrence or rejection and normal liver function were enrolled. All subjects received the hepatitis B vaccine (40 μg) by intramuscular injection at months 0, 1, 2, 6 and 12 after enrollment with continuous administration of NAs. The liver function and anti-HBs titers were measured before each vaccination and HBIG (400U) was administrated intramuscularly when anti-HBs titer was lower than 30 IU/L during the course. The results of routine blood tests, liver function, concentration of immunosuppressant, and HBV-DNA copies were monitored during the research. After completion of the vaccination procedure, recipients were regarded as responders if their anti-HBs greater than 30 IU/L were maintained for up to six months without using HBIG and vaccine.

Results

Twenty-seven patients were enrolled in this study and the average anti-HBs titer before vaccination was 19.86±14.80 IU/L. The average anti-HBs titer of the nine responders at the end of the follow-up was 57.14±22.75 IU/L, giving an overall response rate of 33.3% (9/27). There were no reports of reactivation of HBV, rejection, severe anaphylaxis or other adverse events. Responders and non-responders showed their significant difference in anti-HBs titers after the fourth vaccination (P<0.01). Moreover, the majority of non-responders (11/18, 63.64%) had high LY/EO rates (lymphocyte number/eosinophil number>15) while most responders (8/9, 88.89%) had low LY/EO rates at the beginning of vaccination (P = 0.019).

Conclusions

Active immunization is an effective, cost-saving, and safe method for the prevention of HBV reactivation in patients transplanted for hepatitis B virus related liver diseases. The LY/EO rate may be a valuable indicator in selecting potential recipients for vaccination.

The Management of Hepatitis B in Liver Transplant Recipients

Liver transplant (LT) is now an established indication for patients with chronic hepatitis B, mainly because of the development and use of hepatitis B immunoglobulin (HBIG) and oral antivirals for prophylaxis. The combination of low-dose HBIG and antivirals has been considered the standard prophylaxis regimen to prevent post-LT recurrence of hepatitis B. The important remaining issues are related to the long-term cost of HBIG and the risk of escape hepatitis B virus (HBV) mutants. Strategies for prevention of HBV after LT are constantly improving. With the availability of new nucleoside/nucleotide analogues, new post-LT strategies also should emerge.

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.

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.

Rational Basis for Optimizing Short and Long-term Hepatitis B Virus Prophylaxis Post Liver Transplantation: Role of Hepatitis B Immune Globulin

Antiviral therapy using newer nucleos(t)ide analogues with lower resistance rates, such as entecavir or tenofovir, suppress hepatitis B virus (HBV) replication, improve liver function in patients with compensated or decompensated cirrhosis, and delay or obviate the need for liver transplantation in some patients. After liver transplantation, the combination of long-term antiviral and low-dose hepatitis B Immune globulin (HBIG) can effectively prevent HBV recurrence in greater than 90% of transplant recipients. Some forms of HBV prophylaxis need to be continued indefinitely after transplantation but, in patients with a low-risk of HBV recurrence (i.e., HBV DNA levels undetectable before transplantation), it is possible to discontinue HBIG and maintain only long-term nucleos(t)ide analogue(s) therapy. A more cautious approach is necessary for those patients with high pretransplant HBV DNA levels, those with limited antiviral options if HBV recurrence occurs (i.e., HIV or hepatitis D virus coinfection, preexisting drug resistance), those with a high risk of hepatocellular carcinoma recurrence, and those at risk of noncompliance with antiviral therapy. In this group, HBIG-free prophylaxis cannot be recommended.

The combination of long-term antiviral and low-dose Hepatitis B Immune globulin (HBIG) can effectively prevent HBV recurrence in > 90% of liver transplant recipients. In patients with low HBV DNA levels, nucleos(t)ide analogue(s) treatment without HBIG is possible.

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.

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.

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.

Reestablishment of active immunity against HBV graft reinfection after liver transplantation for HBV-related end stage liver disease

Background. The aim of this study was to establish a hepatitis B virus (HBV) vaccination protocol among orthotopic liver transplantation (OLT) recipients under the coverage of a low-dose hepatitis B immunoglobulin (HBIG) combined with an antiviral agent prophylaxis protocol. Method. Two hundred OLT recipients were included in this study. The vaccine was injected at months 0, 1, 2, and 6. Low-dose HBIG combined with antiviral agent prophylaxis protocol was continued before reestablishment of active immunity against HBV in order to maintain a steady anti-HBs titer. Results. Active immunity against HBV was reestablished in 50 patients, for an overall response rate of 25%. Of the 50 patients, 24 discontinued HBIG without any HBV graft reinfection during a follow-up period of 26.13 ± 7.05 months. 21 patients discontinued both HBIG and antiviral agents during a follow-up period of 39.86 ± 15.47 months, and 4 patients among them appeared to be HBsAg positive. There was no recipient death or graft loss because of HBV reinfection. Conclusions. Vaccination preventing HBV reinfection for OLT recipients is feasible. The strategy withdrawal of HBIG with induction of active immunity against hepatitis B is reasonable for long-term survivors of OLT; however, discontinuation nucleoside analogues should be cautious.

Frequent incidence of escape mutants after successful hepatitis B vaccine response and stopping of nucleos(t)ide analogues in liver transplant recipients

The combination of nucleos(t)ide analogues (NAs) and hepatitis B immune globulin has been established as safe and effective prophylaxis against hepatitis B virus (HBV) reactivation after liver transplantation (LT). However, the essential weak point of this regimen is its high cost. The hepatitis B (HB) vaccine is an attractive alternative that costs less, and it enables some patients to have sufficiently high hepatitis B surface antibody (HBsAb) titers. Almost no data exist on whether NAs can be stopped safely in such successfully vaccinated patients. We investigated the incidence of HB vaccine escape mutants in liver recipients who had sufficient HBsAb titers after LT and stopped NAs. Among 18 HBV carriers and 7 non-HBV patients who received grafts from hepatitis B core antibody-positive donors, 2 HBV carriers and 6 non-HBV patients who achieved HBsAb titers >100 IU/L for >3 months after posttransplant vaccination were weaned from NAs. For the patients who showed viremia, we analyzed amino acid sequences of the HB envelope protein, and we performed a statistical analysis for the factors associated with viremia. In 4 of the 8 patients who achieved sufficient HBsAb levels after vaccination and stopped NAs, HBV DNA appeared after a median of 12 months. A sequence analysis showed various amino acid mutations, including the a-determinant, in the HB envelope region. Frequent vaccination was shown to be a statistically significant risk factor for inducing viremia. In conclusion, although the HB vaccine is an effective substitute for prophylaxis against HBV reactivation in some patients after LT, frequent vaccination could be a risk factor for producing escape mutants. Our data demonstrate not only that caution must be exercised in stopping NAs in effectively vaccinated patients (especially in patients vaccinated frequently) but also that it is important to set stopping rules for vaccination in transplant patients.

Induction of a robust T- and B-cell immune response in non- and low-responders to conventional vaccination against hepatitis B by using a third generation PreS/S vaccine

Non-responsiveness to conventional hepatitis B vaccines in individuals at high risk of exposure to hepatitis B virus (HBV) is an important public health problem and of particular relevance in health care providers. Yeast-derived conventional HBsAg vaccines fail to induce protective antibody titers in up to 10% of immune competent vaccinees. Therefore, a third generation HBV vaccine, Sci-B-Vac™, was developed which contains in addition to the small S antigen the PreS1 and PreS2 antigens. This vaccine proved to induce a highly potent cellular and humoral immune response in healthy individuals as well as protective antibody levels in non- and low-responders to conventional HBV vaccines. The aim of the study was to examine whether Sci-B-Vac™ triggers cellular and humoral immunity in individuals who failed immunization with conventional vaccines. We immunized 21 volunteers (15 non- and 6 low-responders) according to the standard vaccination schedule (0, 4 and 24 weeks), determined the cellular immunity by proliferation assay and interferon (IFN)-γ ELISpot and measured the anti-HBs antibody titers prior to each vaccination and four weeks after the third vaccine dose. Following three vaccinations, PreS/S-specific T-cell proliferation was detected in 8 out of 15 non-responders and 5 out of 6 low-responders. Specific IFN-γ responses were measured in 2 out of 15 non-responders and 4 out of 6 low-responders. All but one (20/21) study participants developed anti-HBs titers ≥10IU/l after three vaccinations. Anti-HBs ≥100IU/L were detected in 12 out of 15 non-responders and in 6 out of 6 low-responders. Anti-HBs ≥10IU/l and <100IU/l were found in 2 non-responders. These results indicate that Sci-B-Vac™ induces cellular immunity as well as protective anti-HBs antibody titers in non- and low-responders. In conclusion, these results confirm that Sci-B-Vac™ should be administered to non-responders to conventional HBV vaccines and patients with impaired immune function.

Review of the pharmacological management of hepatitis B viral infection before and after liver transplantation

The progress in treatment against hepatitis B virus (HBV) with the development of effective and well tolerated nucleotide analogues (NAs) has improved the outcome of patients with HBV decompensated cirrhosis and has prevented post-transplant HBV recurrence. This review summarizes updated issues related to the management of patients with HBV infection before and after liver transplantation (LT). A literature search using the PubMed/Medline databases and consensus documents was performed. Pre-transplant therapy has been initially based on lamivudine, but entecavir and tenofovir represent the currently recommended first-line NAs for the treatment of patients with HBV decompensated cirrhosis. After LT, the combination of HBV immunoglobulin (HBIG) and NA is considered as the standard of care for prophylaxis against HBV recurrence. The combination of HBIG and lamivudine is related to higher rates of HBV recurrence, compared to the HBIG and entecavir or tenofovir combination. In HBIG-free prophylactic regimens, entecavir and tenofovir should be the first-line options. The choice of treatment for HBV recurrence depends on prior prophylactic therapy, but entecavir and tenofovir seem to be the most attractive options. Finally, liver grafts from hepatitis B core antibody (anti-HBc) positive donors can be safely used in hepatitis B surface antigen negative, preferentially anti-HBc/anti-hepatitis B surface antibody positive recipients.

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.

Treatment of patients with HBV-related decompensated cirrhosis and liver transplanted patients

Antiviral therapy using newer nucleos(t)ide analogs with lower resistance rates could suppress hepatitis B virus (HBV) replication, improve liver function in patients with compensated or decompensated cirrhosis, delay or obviate liver transplantation in some patients, and reduce the risk of HBV recurrence. Some form of HBV prophylaxis needs to be continued indefinitely posttransplant. However, in patients with a low-risk of HBV recurrence it is possible to discontinue hepatitis B immunoglobulins and maintain long-term nucleos(t)ide analog therapy. Currently, treatment of posttransplantation hepatitis B is a less important clinical problem than it was historically because effective antiviral therapies exist to rescue patients who failed initial prophylaxis.

Immunogenicity of different hepatitis B virus vaccination schedules in liver transplant recipients

AIM

To compare the immunogenicity of two modified hepatitis B virus (HBV) vaccination schedules in liver transplant recipients. Hepatitis B immunoglobulin (HBIG) in combination with nucleoside/nucleotide analogs (NUCs) is the recommended prophylaxis for preventing HBV recurrence following liver transplantation (LT). However, HBIG treatment is expensive. Active immunization with hepatitis B vaccine would be a preferable alternative prophylaxis to replace HBIG treatment. However, the overall response rate to standard vaccination (given at months 0, 1 and 6) is relatively low in immune-compromised patients.

METHODS

Two cohorts of 114 subjects were immunized with recombinant HBV vaccine containing S-antigen. The patients in the rapid schedule group were immunized with 40 μg HBV vaccine at months 0, 1, 2 and 3, and with 20 μg at months 4, 5 and 6. The patients in the accelerated schedule group were immunized with 40 μg of HBV vaccine at days 0, 7, 14 and 28, and 20 μg at months 2, 3 and 4.

RESULTS

The overall response rate was 16.7% (19/114) and all responders discontinued HBIG injection and only one patient developed HBV recurrence. The response rate was 24.6% (14/57) and 8.8% (5/57) in the rapid vaccination and the accelerated vaccination schedules, respectively (P = 0.024).

CONCLUSION

HBV vaccination may induce endogenous anti-HBs to replace HBIG in selected patients. Vaccination schedules may influence vaccine response, and individual optimization may improve response rate to HBV vaccination.

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.

Future prevention and treatment of chronic hepatitis B infection

Vaccination for hepatitis B virus (HBV) infection and treatment for chronic hepatitis B, while effective for primary prevention and control of the disease, still have their limitations. Global coverage of HBV immunization needs improvement. Several patient populations are noted to have suboptimal seroprotective rates after HBV vaccination. There are currently several potential new vaccines undergoing animal and human studies, most notably vaccines containing immunostimulatory DNA sequences. Long-term nucleoside analogue therapy is necessary in achieving permanent virologic suppression. Potential new treatments explore new mechanisms of action, including the inhibition of hepatitis B surface antigen release, targeting antifibrotic mechanism, and immunomodulation through novel interferons and therapeutic vaccines. The clinical application of potential new vaccines and therapies would enhance the prevention of HBV infection and treatment of chronic hepatitis B.

Anti-hepatitis B surface immunoglobulin reduction in early postoperative period after liver transplantation in hepatitis B virus-positive patients

AIM

  We investigated a protocol that lowered the necessary dose of anti-hepatitis B surface immunoglobulin (HBIg) with frequent monitoring of hepatitis B surface antigen (HBsAg) and antibody (HBsAb) levels in the early post-transplant period.

METHODS

  Fifteen hepatitis B virus (HBV)-positive patients were studied. We administered a nucleoside analog from the preoperative period, high dose HBIg was used intraoperatively (200 IU/kg in the patients who weighed less than 50 kg, and 10 000 IU in those who weighed more than or equal to 50 kg) and was continued every day (5000-10 000 IU/day). Thereafter, HBIg was administered to keep the target trough titers. We evaluated the effectiveness and safety of this protocol for preventing HBV reactivation.

RESULTS

  The average use of HBIg during the first three postoperative months (POM) was 27.9 ± 9.6 Kilo International Units. The average cost was $US11 800 in the first three postoperative months, compared with other previously reported protocols (about $20 000-40 000). HBV reactivation was detected in only one patient (6.7%) during the median follow up of 64 months (range: 12-86 months).

CONCLUSIONS

  The present protocol for HBIg administration, which used frequent monitoring of HBsAg and HBsAb levels to determine the minimum required dose, was both safe and effective, and contributed to overall cost saving after liver transplantation.

Hepatitis B virus S gene escape mutants

Hepatitis B virus (HBV) can be classified into nine immunological subtypes or eight genotypes. The most prevalent genotypes in Asia are genotypes B and C. HBV is transmitted parenteraly and can produce either asymptomatic or symptomatic disease. Although the consequences of acute hepatitis B can be severe, serious sequelae are associated with chronic infections. HBV seroprevalence ranges from intermediate (2%-7%) to high (≥8%) levels in Asia. Several strategies for the control and prevention of HBV infection have been found to be efficacious. They include vaccination and the administration of HBIG, interferon-a and nucleoside/nucleotide analogues. However, these procedures also apply selective pressures on HBV in infected individuals leading to the generation and accumulation of mutations in the S gene. Most of these mutations occur in the major hydrophilic region (MHR) of the S gene. These mutations create public health concerns as they can be responsible for reactivation of hepatitis B and occult hepatitis B infection. The inability to detect occult infections means that these individuals may become blood donors. This suggests that new strategies for donor evaluation and selection may need to be developed to protect the blood supply.

Entecavir monotherapy is effective in suppressing hepatitis B virus after liver transplantation

BACKGROUND & AIMS

We investigated the efficacy of entecavir, a cyclopentyl guanosine nucleoside analogue, as monoprophylaxis in patients with chronic hepatitis B who received a liver transplant.

METHODS

We studied data from 80 consecutive patients who received a liver transplant (47 from living donors and 33 from deceased donors) for hepatitis B-related disease and entecavir monotherapy as prophylaxis. None of the patients received hepatitis B immunoglobulin. Indications for transplant included decompensation from cirrhosis (27.5%), acute-on-chronic hepatitis B (47.5%), and hepatocellular carcinoma (25%). The median follow-up time was 26 months (range, 5-40 months). Before transplant, 33 patients were not on antiviral therapy and 47 were on oral therapy (18 had received less than 3 months of treatment).

RESULTS

At the time of transplant, the median log HBV DNA level was 3.5 copies/mL (range, 1.54-8.81); 21 patients (26%) had undetectable levels of HBV DNA. The cumulative rate of hepatitis B surface antigen (HBsAg) loss was 86% and 91% after 1 and 2 years, respectively. Ten patients had reappearance of HBsAg. Eighteen patients (22.5%) were HBsAg positive at the time of their last examination; 17 of these had undetectable levels of HBV DNA, and the remaining patient had a low level of HBV DNA (217 copies/mL). There was no evidence of mutations at sites that confer resistance to entecavir among patients who were HBsAg positive.

CONCLUSIONS

Although only 26% of patients had complete viral suppression at the time of transplant, 91% lost HBsAg, with 98.8% achieving undetectable levels of HBV DNA. A hepatitis B immunoglobulin-free regimen of entecavir monotherapy is effective after liver transplantation for chronic hepatitis B.

Prevention of post liver transplant HBV recurrence

BACKGROUND

Twenty years ago, liver transplantation for hepatitis B had been a relative contraindication to universal HBV recurrence and poor outcomes. Over the ensuing two decades, there has been refinement of prevention strategies in order to minimize HBV recurrence in the allograft.

RESULTS

Currently, the most efficacious and cost-effective strategies include newer oral antiviral drugs in combination with low doses of hepatitis B immunoglobulin (HBIG). More recently, strategies have been successful in withdrawing HBIG and newer approaches of HBIG avoidance are currently under development.

CONCLUSION

Thus, 20 years afterward, HBV recurrence is <5% and outcomes following liver transplantation are excellent.

Engineering virus-specific T cells that target HBV infected hepatocytes and hepatocellular carcinoma cell lines

BACKGROUND & AIMS

Virus-specific T cells capable of controlling HBV and eliminating hepatocellular carcinoma (HCC) expressing HBV antigens are deleted or dysfunctional in patients with chronic HBV or HBV-related HCC. The goal of this study was to determine if T cell receptor (TCR) gene transfer can reconstitute HBV-specific T cell immunity in lymphocytes of chronic HBV patients and investigate whether HCC cells with natural HBV-DNA integration can be recognized by genetically modified T cells.

METHODS

We used vector-mediated gene transfer to introduce HLA-A2-restricted, HBV-specific TCRs into T cells of chronic HBV as well as HBV-related HCC patients.

RESULTS

The introduced TCRs were expressed on the cell surface, evidenced by Vβ and pentamer staining. TCR transduced T cells produced IFN-γ, TNF-α, IL-2, and lysed HBV infected hepatocyte-like cell lines. Furthermore, HCC cell lines with natural HBV-DNA integration could be recognized by HBV-specific TCR-re-directed T cells.

CONCLUSIONS

TCR re-directed HBV-specific T cells generated from PBMC of chronic HBV and HBV-related HCC patients were multifunctional and capable of recognizing HBV-infected cells and HCC tumor cells expressing viral antigens from naturally integrated HBV DNA. These genetically modified T cells could be used to reconstitute virus-specific T cell immunity in chronic HBV patients and target tumors in HBV-related HCC.

Different effect of HBV vaccine after liver transplantation between chronic HBV carriers and non-HBV patients who received HBcAb-positive grafts

BACKGROUND

Combination of nucleos(t)ide analogue and anti-HBs immunoglobulin (HBIg) is the standard protocol for prevention of HBV reactivation after liver transplantation, but because of the extremely high cost of HBIg, HBV vaccine is tried as a much cheaper and potentially safer substitute. Here we show the different effect of HBV vaccine between chronic HBV carrier and non-HBV patients who received grafts from HBc antibody-positive donors.

METHODS

Fifteen chronic HBV carriers and 6 non-HBV patients who received grafts from HBc antibody-positive donors were included in this study. These patients received double dose of pre-S-containing HBV vaccine every month from later than 12 months after liver transplantation. Successful vaccination was defined as HBsAb >100 IU/l without HBIg administration for 3 months.

RESULTS

None of the 15 chronic HBV carriers succeeded in maintaining high enough HBsAb titers. In contrast, 5 of 6 non-HBV patients with HBcAb-positive donors achieved HBsAb >100 IU/l without HBIg coadministration. Recipient HBV status (HBV carrier/non-HBV) was considered to have a stronger effect on vaccine success (p < 0.001) though recipient age (p = 0.006) was also selected as a significant factor.

CONCLUSIONS

Recipient HBV status seems to be the most important factor affecting success of HBV vaccine after liver transplantation. In non-HBV patients who received grafts from HBcAb-positive donors, HBV vaccination is an effective, cost-saving, and safe method for prevention of HBV reactivations. In contrast in chronic HBV patients, response rate was quite poor, so some modifications such as combination with adjuvant or modification of administration schedules should be considered.

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.

Management of end-stage liver disease in chronic hepatitis B

The consequences of chronic hepatitis B virus infection include hepatocellular carcinoma and liver cirrhosis. Effective antiviral therapy in patients with hepatitis B with advanced liver disease with viral suppression and sustained HBeAg seroconversion (where applicable) may abort hepatic decompensation, diminish hepatocellular risk, and reduce the risk of viral recurrence after transplantation. Overt hepatic decompensation is an indication for referral to a transplant center.

Long-term efficacy of nucleoside monotherapy in preventing HBV infection in HBsAg-negative recipients of anti-HBc-positive donor livers

BACKGROUND AND AIM

Transmission of hepatitis B virus (HBV) infection occurs in up to 87.5% of HBsAg-negative recipients of anti-HBc-positive donor livers in the absence of HBV prophylaxis. There is no standardized prophylactic regimen to prevent HBV infection in this setting. The aim of this study was to determine the long-term efficacy of nucleoside analogue to prevent HBV infection in this setting.

METHODS

A retrospective study of HBsAg-negative patients receiving liver transplantation (LT) from anti-HBc-positive donors during a 10-year period.

RESULTS

Twenty patients were studied, mean age was 50.2 ± 8.3 years, 40% were men, and 90% were Caucasian. The median MELD score at the time of LT was 18 (12-40). None of the patients received hepatitis B immune globulin. Eighteen patients received nucleoside analogue monotherapy: 10 received lamivudine and 8 received entecavir. None of these 18 patients developed HBV infection after a median follow up of 32 (1-75) months. One patient received a second course of hepatitis B vaccine 50 months after LT with anti-HBs titer above 1,000 mIU/mL. Lamivudine was discontinued and the patient remained HBsAg negative 18 months after withdrawal of lamivudine. Two patients who were anti-HBs positive before LT were not started on HBV prophylaxis after LT; both developed HBV infection after LT.

CONCLUSIONS

Nucleoside monotherapy is sufficient in preventing HBV infection in HBsAg-negative recipients of anti-HBc-positive donor livers. HBV prophylaxis is necessary in anti-HBs-positive recipients of anti-HBc-positive donor livers.

Current management of hepatitis B virus infection before and after liver transplantation

The progress in treatment against hepatitis B virus (HBV) has substantially improved the outcome of all HBV-infected patients. We systematically reviewed the existing data in the management of HBV transplant patients in order to assess the optimal regimen in the pretransplant setting, for post-transplant prophylaxis and for therapy of HBV recurrent infection. All data suggest that an effective pretransplant anti-HBV therapy prevents post-transplant HBV recurrence. Pretransplant therapy has been based on lamivudine with addition of adefovir upon lamivudine resistance, but the use of newer, potent high-genetic barrier agents is expected to improve long-term efficacy. Moreover, it may lead to improvement of liver function, which sometimes removes the need for transplantation, although more objective criteria for removal from waiting lists are required. After liver transplantation, the combination of HBV immunoglobulin and one nucleos(t)ide analogue, mostly lamivudine, is currently the best approach, almost eliminating the probability of HBV recurrence. Treatment of post-transplant HBV recurrence has been mainly studied with lamivudine, but it will be most effective with entecavir and tenofovir, which have a low risk of resistance. In conclusion, the newer anti-HBV agents improve the treatment of HBV both pretransplant and post-transplant. HBV immunoglobulin is still used in combination with an anti-HBV agent for post-transplant prophylaxis. Monoprophylaxis with one of the new anti-HBV agents might be possible, particularly in patients preselected as having a low risk of HBV recurrence, but further data are needed and strategies to ensure compliance must be used.

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.

Double-dose double-phase use of second generation hepatitis B virus vaccine in patients after living donor liver transplantation: Not an effective measure in transplant recipients

AIMS

Post-transplant active immunization for chronic hepatitis B patients has been attempted in several studies with controversial results. We assessed the effect of a double-dose double-phase vaccination regimen among partial living donor liver recipients.

METHODS

Eighteen patients who underwent liver transplantation (LT) for chronic hepatitis B and two non-hepatitis B virus (HBV)-infected patients who received hepatitis B core antibody (HBcAb)-positive donor organs were recruited 18-78 months after LT. All were on hepatitis B immunoglobulin (HBIG) mono-prophylaxis before and throughout vaccination, to maintain hepatitis B surface antibody (HBsAb) titers of more than 100 IU/mL. Recombinant hepatitis B surface antigen vaccine (40 microg) was administered intramuscularly during weeks 0, 4, 8, 24, 28 and 32.

RESULTS

The patients consisted of 15 males and five females with a median age of 52 (39-59) years. None developed a sufficient HBsAb titer above 500 IU/mL by week 48. In two patients whose maximum HBsAb titer increased to above 300 IU/mL, we attempted to skip HBIG, but shortly thereafter the titer dropped below 100 IU/mL and HBIG administration was resumed. Although the HBIG dose was reduced during and after vaccination, cessation of administration was not achieved.

CONCLUSION

Double-dose double-phase use of second generation recombinant vaccine was not effective in this study population. The selected population should be targeted for a conventional vaccine regimen, and different approaches, such as strong adjuvant or pre-S containing protein, should be further tested in a larger number of patients after LT for chronic hepatitis B.

A randomized study of adefovir dipivoxil in place of HBIG in combination with lamivudine as post-liver transplantation hepatitis B prophylaxis

Prior to effective prophylaxis, liver transplantation for hepatitis B virus (HBV)-related disease was frequently complicated by recurrence, which could be severe and rapidly progressive. Combination hepatitis B immunoglobulin (HBIG) and lamivudine prophylaxis reduces this rate of recurrence to <5% at 5 years; however, HBIG administration is costly and inconvenient. We conducted a multicenter randomized study of adefovir dipivoxil substitution for low-dose intramuscular (IM) HBIG in patients without HBV recurrence at least 12 months posttransplantation for HBV-related disease. Thirty-four patients were randomized, 16 to adefovir (1 patient withdrew consent at 3 months and is not considered in the results) and 18 to continue HBIG. All continued lamivudine. Groups were well matched by age, sex, and time since transplantation (median, 4.5 years), and background virological risk for HBV recurrence (30% of patients in the adefovir group, 24% in the HBIG group having detectable HBV DNA at transplantation). All patients were alive at study completion without recurrence. One patient in the adefovir group became hepatitis B surface antigen-positive at 5 months but was persistently HBV DNA undetectable via polymerase chain reaction (sensitivity 14 IU/mL) over the following 20 months. Median creatinine was not significantly changed over the course of the study in either group. One patient in the adefovir group with a background of diabetic and hypertensive nephropathy (baseline creatinine 150 micromol/L) developed increased creatinine leading to dose reduction and ultimately cessation of adefovir at 15 months. Yearly cost of combination adefovir/lamivudine prophylaxis was $8,290 versus $13,718 IM HBIG/lamivudine.

CONCLUSION

Compared with combination HBIG plus lamivudine prophylaxis, combination adefovir plus lamivudine provides equivalent protection against recurrent HBV infection but with better tolerability and less cost.

Liver transplantation for hepatitis B: what is the best hepatitis B immune globulin/antiviral regimen?

1. Prophylaxis using the combination of lamivudine and high-dose intravenous hepatitis B immunoglobulin (approximately 10,000 IU monthly) reduces the long-term risk of recurrence of hepatitis B in hepatitis B surface antigen-positive transplant recipients to 5% to 10%. However, this therapy is expensive and inconvenient for patients. 2. Recent studies have shown that similar results can be obtained, at far less cost, with much lower doses of intramuscular hepatitis B immune globulin (400-800 IU monthly) in combination with pretransplant and posttransplant lamivudine therapy. 3. The development of lamivudine resistance pre-transplant can lead to hepatic decompensation and increases the risk of posttransplant recurrence in patients receiving hepatitis B immune globulin/lamivudine prophylaxis. Newer nucleos(t)ide analogues with lower resistance rates such as entecavir, adefovir, and tenofovir should therefore replace lamivudine in hepatitis B prophylaxis. 4. Combination therapy with these newer agents and low-dose intramuscular hepatitis B immune globulin is likely to be the most cost effective hepatitis B immune globulin-containing regimen for the prevention of hepatitis B recurrence post-transplant. 5. Some form of hepatitis B virus prophylaxis needs be continued indefinitely post-transplant. However, the use of antivirals with very low rates of drug resistance will make it possible to stop hepatitis B immune globulin therapy in many patients currently receiving hepatitis B immune globulin/nucleos(t)ide combination therapy.

Prevention of hepatitis B recurrence after living donor liver transplantation: primary high-dose hepatitis B immunoglobulin monotherapy and rescue antiviral therapy

The prevention of hepatitis B virus (HBV) recurrence is essential after liver transplantation in patients infected with HBV. We evaluated the efficacy of primary high-dose hepatitis B immunoglobulin (HBIG) monotherapy and rescue antiviral therapy in 639 HBV-infected adult patients who underwent living donor liver transplantation (LDLT) between February 1997 and December 2004. The overall 5-year survival rate was 80.7%, and recurrence of hepatocellular carcinoma was the most common cause of late mortality. Pretransplant HBV replication was observed in 392 (61.3%) patients. The interval of 10,000-IU HBIG administration to maintain antibody to hepatitis B surface antigen > 500 IU/L was 30 days in 11.4% patients, 40 to 50 days in 72.1%, and 60 days in 16.5%. At the last follow-up, 3.9% of the patients without HBV recurrence were receiving combination therapy. Overall 1-year, 3-year, 5-year, and 10-year HBV recurrence rates were 1.4%, 5.5%, 7.3%, and 8.5%, respectively. HBV recurrence occurred after a mean of 25.7 +/- 16.4 months after LDLT. After HBV recurrence, 5 of 9 patients died from rapidly progressive liver failure before treatment with adefovir, and only 1 of 29 patients died after treatment with adefovir. Need for frequent HBIG infusions (< or =30 days), active pretransplant HBV replication, and hepatocellular carcinoma recurrence were significant risk factors for HBV recurrence and indications for combination therapy. Our posttransplant HBV prophylaxis regimen resulted in a 5-year HBV recurrence rate of 7.3% and a mortality rate of 13.2% after HBV recurrence, showing the effectiveness of high-dose HBIG monotherapy and rescue antiviral therapy.