Mechanisms of hepatitis B virus graft reinfection and graft damage after liver transplantation

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.

Long-term consequences of stopping HBIG and/or nucleotide analogues in liver transplant recipients administered hepatitis B vaccination to prevent HBV reinfection

BACKGROUND

The long-term administration of nucleotide analogues (NAs) and hepatitis B immune globulin (HBIG) comprises standard prophylaxis for patients with hepatitis B virus (HBV)-related liver diseases to prevent HBV reinfection after liver transplantation (LT). However, prolonging the prophylaxis strategy involves safety issues, such as the development of escape mutations and/or emerging resistant strains, and is also associated with high costs; further, it remains unclear how long prophylactic treatment should be continued.

METHOD

Liver transplantation recipients responding to hepatitis B vaccination due to HBV-related liver diseases were retrospectively analysed after stopping HBIG and/or NAs, administered to prevent HBV reinfection, after long-term follow-up. The safety and effectiveness of the strategy were then evaluated for these responders.

RESULT

Seventy-eight responders were enrolled. All responders discontinued HBIG, among which 36 stopped both HBIG and NAs. During follow-up, four recipients experienced HBV reinfection, which was associated with HBV escape mutations, after the withdrawal of both HBIG and NAs. No death or graft loss occurred in recipients during the follow-up period.

CONCLUSION

A careful withdrawal of HBIG and/or NAs is feasible and safe for responders to hepatitis B vaccination receiving transplants for HBV-related liver diseases.

Association of the Interleukin-27 Gene Expression and Hepatitis B Virus Infection in Liver Transplanted Patients

OBJECTIVES

Hepatitis B viral infection is among the most common causes of cirrhosis and hepatocellular carcinoma and a frequent viral indication for liver transplant. Cytokine-mediated immunity plays a critical role in introducing and promoting hepatitis B virus outcomes and in graft microenvironment. Interleukin 27 is a heterodimeric cytokine and a member of interleukin-6/interleukin-12 family. Interleukin-27 shows a broad range of pro- and antiinflammatory properties and plays a determining role during immune responses in combating hepatitis B virus. Therefore, in this study, the possible association between expressions of interleukin-27 gene with hepatitis B virus infection was evaluated in liver transplant patients.

MATERIALS AND METHODS

In a cross-sectional study from liver transplant patients with the risk of hepatitis B virus infection who admitted to Namazi Hospital affiliated to Shiraz University of Medical Sciences, 50 patients were selected and subgrouped to 25 hepatitis B virus-infected and 25 noninfected ones between years 2011 and 2013. The 25 healthy controls also were enrolled in this study. The presence of hepatitis B virus infection was assessed using polymerase chain reaction and enzyme-linked immunosorbent assay protocols in liver transplant patients. In addition, the interleukin-27 gene expression level was analyzed using an in-house-SYBER Green real time polymerase chain reaction method. The rate of interleukin-27 gene expression level was statistically analyzed in studied patient groups and controls using the Livak (2-▵▵CT) method.

RESULTS

The expression level of interleukin-27 gene was increased 10.27- and 2.36-fold in hepatitis B virus-infected and uninfected liver transplanted patients compared with healthy controls.

CONCLUSION

Hepatitis B virus infection can lead to overexpression of interleukin-27 gene in liver transplant patients compared with uninfected ones and controls. However, further studies are needed to characterize the effective antihepatitis B virus effects of interleukin-27 in liver transplant patients.

The analysis of correlation between IL-12 gene expression and hepatitis B virus in the affected patients

Hepatitis B viral (HBV) infection, which is one of the global public health concerns, is among the most common causes of cirrhosis and hepatocellular carcinoma. It was proposed that cytokine-mediated immunity plays a critical role in determining the outcomes of hepatitis B virus infection. Interleukin 12 (IL-12) is a heterodimeric cytokine that shows a broad range of immunoregulatory properties during immune responses and combats host invading pathogens. The main purpose of this study was to investigate the possible association between expression levels of IL-12 gene with HBV infection in patients with HBV infection. This clinical study was performed on 30 HBV patients and 30 healthy controls. SYBR Green Real-time PCR was performed to examine the expression level of IL-12 gene in HBV patients. Then, the rate of expression was calculated using the Livak ([Formula: see text] ) method. ΔCT of samples in the two groups were compared using t test method. PCR was also used for HBV-DNA evidence. The results of our study demonstrated that the difference in mean of IL-12 gene expression between healthy subjects and HBV patients is statistically significant.

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.

Individualized management of pregnant women with high hepatitis B virus DNA levels

Hepatitis B is a major health concern in the Asia-Pacific region, and is endemic in China, Southeast Asia, and Africa. Chronic hepatitis B virus (HBV) infection may cause hepatic cirrhosis and liver cancer. It is estimated that there are more than 350 million chronic HBV carriers worldwide, of whom approximately one quarter will die of chronic hepatitis B-related liver diseases. HBV is transmitted horizontally through blood and blood products or by sexual transmission, and vertically from mother to infant. Perinatal infection is the predominant mode of transmission in countries with a high prevalence of hepatitis B surface antigen (HBsAg) carriage, and perinatal transmission leads to high rates of chronic infection. Therefore, it is important to prevent the mother-to-child transmission (MTCT) of HBV. Research has shown that pregnant women with high HBV DNA levels have an increased risk of MTCT. However, most of the obstetrics guidelines do not make a distinction between pregnant women with high HBV DNA levels and those who are HBsAg positive only. This review addresses the management of pregnant women with high levels of HBV viremia, in terms of antiviral therapy, use of hepatitis B immunoglobulin (HBIG), the combined application of hepatitis B vaccine and HBIG, choice of delivery mode and feeding practices.

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 immunoglobulin injection in pregnancy to interrupt hepatitis B virus mother-to-child transmission-a meta-analysis

OBJECTIVES

To evaluate the efficacy and safety of using hepatitis B immunoglobulin (HBIG) during pregnancy to prevent hepatitis B virus (HBV) mother-to-child transmission (MTCT).

METHODS

We systematically reviewed the effect of HBIG in decreasing HBV MTCT from randomized controlled trials (RCTs) carried out between January 1990 and December 2008, in English and Chinese languages. Multiple databases were searched, and experts in this field were contacted. The methodological quality of each RCT was assessed by the Jadad score. We abstracted data on HBV intrauterine infection, MTCT, treatment methods, newborn immune prophylaxis methods, and adverse effects. A Mantel-Haenszel random-effects model was employed for all analyses using odds ratios (OR) and 95% confidence intervals (95% CI).

RESULTS

Five thousand nine hundred newborns of asymptomatic hepatitis B surface antigen (HBsAg)-seropositive mothers from 37 qualified RCTs were included. Compared with the control group, newborns in the HBIG group had a lower intrauterine infection rate (indicated by HBsAg as OR 0.22, 95% CI [0.17, 0.29], from 32 RCTs; indicated by HBV DNA as OR 0.15, 95% CI [0.07, 0.30], from 13 RCTs; p<0.01 for both) and a higher protection rate (indicated by hepatitis B surface antibody (HBsAb) as OR 11.79, 95% CI [4.69, 29.61], from 15 RCTs; p<0.01). The same trend was found in MTCT by the time of 9-12 months after birth, indicated by HBsAg (OR 0.33, 95% CI [0.21, 0.51], from nine RCTs; p<0.01) and HBsAb (OR 2.49, 95% CI [1.55, 4.01], from 11 RCTs; p<0.01). HBIG appears to be safe, but a few RCTs have reported adverse events.

CONCLUSION

Multiple injections of HBIG in HBV carrier mothers with a high degree of infectiousness in late pregnancy, effectively and safely prevent HBV intrauterine transmission.

Differential impact of immune escape mutations G145R and P120T on the replication of lamivudine-resistant hepatitis B virus e antigen-positive and -negative strains

Immune escape variants of the hepatitis B virus (HBV) represent an emerging clinical challenge, because they can be associated with vaccine escape, HBV reactivation, and failure of diagnostic tests. Recent data suggest a preferential selection of immune escape mutants in distinct peripheral blood leukocyte compartments of infected individuals. We therefore systematically analyzed the functional impact of the most prevalent immune escape variants, the sG145R and sP120T mutants, on the viral replication efficacy and antiviral drug susceptibility of common treatment-associated mutants with resistance to lamivudine (LAM) and/or HBeAg negativity. Replication-competent HBV strains with sG145R or sP120T and LAM resistance (rtM204I or rtL180M/rtM204V) were generated on an HBeAg-positive and an HBeAg-negative background with precore (PC) and basal core promoter (BCP) mutants. The sG145R mutation strongly reduced HBsAg levels and was able to fully restore the impaired replication of LAM-resistant HBV mutants to the levels of wild-type HBV, and PC or BCP mutations further enhanced viral replication. Although the sP120T substitution also impaired HBsAg secretion, it did not enhance the replication of LAM-resistant clones. However, the concomitant occurrence of HBeAg negativity (PC/BCP), sP120T, and LAM resistance resulted in the restoration of replication to levels of wild-type HBV. In all clones with combined immune escape and LAM resistance mutations, the nucleotide analogues adefovir and tenofovir remained effective in suppressing viral replication in vitro. These findings reveal the differential impact of immune escape variants on the replication and drug susceptibility of complex HBV mutants, supporting the need of close surveillance and treatment adjustment in response to the selection of distinct mutational patterns.

Recombinant interferon-alpha2b improves immune response to hepatitis B vaccination in haemodialysis patients: results of a randomised clinical trial

The use of adjuvants capable of improving the deficient immune response to hepatitis B virus (HBV) vaccine in haemodialysis patients is highly needed. Among potential adjuvants, type I interferons deserve a special attention in view of their known effects promoting cellular and humoral immune responses. The aim of the present trial was to evaluate the effects of recombinant interferon-alpha2b (IFN) administered as an adjuvant of HBV vaccine in unvaccinated haemodialysis patients. A significant and early enhancing effect on the antibody response was observed in patients receiving IFN. In addition, a predominance of IgG1 anti-HBs along with a transient normalization of circulating Th1 lymphocytes was only found in patients receiving IFN who achieved an early seroprotection. However, 6 months after the last vaccine dose, no significant differences were observed in the seroprotection rate achieved in patients vaccinated with IFN compared to that in patients receiving HBV vaccine alone. Mild to moderate fever, asthenia, and arthromyalgia were the most common reactions that occurred in vaccinees given IFN. In conclusion, addition of IFN to HBV vaccine, under the conditions used in this trial, is safe and achieves an earlier and higher seroprotection rate improving Th1-dependent immune response in haemodialysis patients.

A novel approach of prophylaxis to HBV recurrence after liver transplantation

Liver transplantation (LT) in patients with hepatitis B virus (HBV) infection is associated with a high rate of graft loss and poor survival, unless re-infection can be prevented. Human hepatitis B immune globulin (HBIG) and nucleoside analogues (NA) have long been utilized to prevent re-infection. Previously, we generated a human monoclonal antibody (mAb), HB that recognizes the surface antigen of hepatitis B virus (HBV). We have constructed a secreted version of HB and cloned its genes into recombinant adeno-associated virus (AAV). We compared the efficiency of AAV vector after a single injection via intramuscular or intravenous routes without additional intervention. Then, we evaluated the activity of antibody HB in tree shrews treated with rAAV-HB and in vitro experiments. So, intramuscular injection of rAAV-HB was a suitable method for the immunoprophylaxis of HBV infection. This human antibody will be useful for the immunoprophylaxis of HBV infection.

Recipient cytotoxic T lymphocyte antigen-4 +49 G/G genotype is associated with reduced incidence of hepatitis B virus recurrence after liver transplantation among Chinese patients

BACKGROUND

Single-nucleotide polymorphisms (SNP) of two-gene locus cytotoxic T lymphocyte antigen-4 (CTLA-4) +49 and CD86 +1057 were previously reported to influence the outcome of liver transplantation (LT) with respect to allograft acceptance. SNP at CTLA-4 +49 was also suggested to be associated with the individual difference in the clearance of hepatitis B virus (HBV). However, their influence on the incidence of post-LT HBV reinfection was not clear. With the increasing knowledge of costimulatory mechanisms on LT and host immune response, we designed this study to investigate the relationship between different alleles as well as genotypes at these two locations and HBV reinfection after LT.

METHODS

Genomic DNA from 167 LT recipients with HBV-related diseases was genotyped for CTLA-4 +49 and CD86 +1057 genomic polymorphisms using a sequence-specific primer-polymerase chain reaction (PCR-SSP). HBV recurrence was diagnosed based on the serological and pathological finding of HBV DNA and HBsAg.

RESULTS

The present study indicated that the recipients with CTLA-4 +49 GG genotype had a reduced risk (6.67%) of HBV recurrence compared with non-CTLA-4 +49 GG-carrying individuals (20.7%) (relative risk 3.098) (P=0.032). The allelic frequency of CTLA-4 +49 G was also significantly lower in patients with HBV recurrence, compared with that in patients without HBV recurrence (P=0.013, odds ratio 2.176, 95% confidence interval 1.170-4.046). However, no significant association was found between CD86 +1057 and HBV recurrence.

CONCLUSION

Our result on CTLA-4 +49 A/G polymorphism indicated that the CTLA-4 +49 GG genotype was related to a reduced risk in the incidence of HBV recurrence.

Response to an experimental HBV vaccine permits withdrawal of HBIg prophylaxis in fulminant and selected chronic HBV-infected liver graft recipients

Strategies using lamivudine and hepatitis B immunoglobulins (HBIg) for prevention of hepatitis B virus (HBV) reinfection after liver transplantation (LT) are expensive since life-long treatment is needed. We evaluated the possibility to obtain protective hepatitis B surface antigen (HBsAg) antibody (anti-HBs) titers after LT and to discontinue HBIg prophylaxis after a reinforced course of vaccination against HBV using an experimental adjuvant HBsAg / AS04 vaccine (GlaxoSmithKline Biologicals [GSK], Rixensart, Belgium) in patients transplanted for hepatitis B. Fifteen LT patients on stable low-level immunosuppression were vaccinated with a double dose of the vaccine at 0, 1, 2, 6, and 12 months: 5 patients were transplanted for nonviral diseases and 10 patients were transplanted for HBV on HBIg monotherapy. HBIg were continued during baseline vaccination (0, 1, and 2 months) and when anti-HBs titers determined every 6 weeks dropped below 150 IU/L. Overall follow-up was 18 months. Sustained long-term response to vaccination was defined as anti-HBs titers >500 IU/L without further need for HBIg administration during a follow-up period of at least 12 months. Overall sustained response to vaccination was 53% (8 / 15 patients); 80% (4 / 5 patients) in the nonviral disease group and 40% (4 / 10 patients) in the HBV group (2 /2 fulminant and 2/8 chronically infected patients) developed a sustained long-term response and were completely free of HBIg at the end of the 18-month follow-up. No HBV recurrence, rejection episodes, or side effects occurred during the follow-up. In conclusion, protective anti-HBs titers were obtained in a substantial number of LT patients following a reinforced course of HBV vaccination with vaccines containing new immunostimulating adjuvants. Vaccination seems well tolerated and safe and allows long-term discontinuation of HBIg.