Decision analysis model for hepatitis B prophylaxis one year after liver transplantation

A 6-month mixed-effect pharmacokinetic model for post-transplant intravenous anti-hepatitis B immunoglobulin prophylaxis

Background

Although individualized dosage regimens for anti-hepatitis B immunoglobulin (HBIG) therapy have been suggested, the pharmacokinetic profile and factors influencing the basis for individualization have not been sufficiently assessed. We sought to evaluate the pharmacokinetic characteristics of anti-HBIG quantitatively during the first 6 months after liver transplantation.

Methods

Identical doses of 10,000 IU HBIG were administered to adult liver transplant recipients daily during the first week, weekly thereafter until 28 postoperative days, and monthly thereafter. Blood samples were obtained at days 1, 7, 28, 84, and 168 after transplantation. Plasma HBIG titer was quantified using 4 different immunoassay methods. The titer determined by each analytical method was used for mixed-effect modeling, and the most precise results were chosen. Simulations were performed to predict the plausible immunoglobulin maintenance dose.

Results

HBIG was eliminated from the body most rapidly in the immediate post-transplant period, and the elimination rate gradually decreased thereafter. In the early post-transplant period, patients with higher DNA titer tend to have lower plasma HBIG concentrations. The maintenance doses required to attain targets in 90%, 95%, and 99% of patients were ~15.3, 18.2, and 25.1 IU, respectively, multiplied by the target trough level (in IU/L).

Conclusion

The variability (explained and unexplained) in HBIG pharmacokinetics was relatively larger in the early post-transplant period. Dose individualization based upon patient characteristics should be adjusted focusing quantitatively on the early post-transplant period.

Biological effects of bone marrow mesenchymal stem cells on hepatitis B virus in vitro

The aim of the present study was to explore the effects of co‑culturing bone marrow‑derived mesenchymal stem cells (BM-MSCs) cultured with hepatitis B virus (HBV)‑infected lymphocytes in vitro. BM‑MSCs and lymphocytes from Brown Norway rats were obtained from the bone marrow and spleen, respectively. Rats were divided into the following five experimental groups: Group 1, splenic lymphocytes (SLCs); group 2, HepG2.2.15 cells; group 3, BM‑MSCs + HepG2.2.15 cells; group 4, SLCs + HepG2.2.15 cells; and group 5, SLCs + BM‑MSCs + HepG2.2.15 cells. The viability of lymphocytes and HepG2.2.15 cells was assessed using the MTT assay at 24, 48 and 72 h, respectively. Levels of supernatant HBV DNA and intracellular HBV covalently closed circular DNA (cccDNA) were measured using quantitative polymerase chain reaction. Supernatant cytokine levels were measured by enzyme‑linked immunosorbent assay (ELISA). T cell subsets were quantified by flow cytometry using fluorescence‑labeled antibodies. In addition, the HBV genome sequence was analyzed by direct gene sequencing. Levels of HBV DNA and cccDNA in group 5 were lower when compared with those in group 3 or group 4, with a significant difference observed at 48 h. The secretion of interferon‑γ was negatively correlated with the level of HBV DNA, whereas secretion of interleukin (IL)‑10 and IL‑22 were positively correlated with the level of HBV DNA. Flow cytometry demonstrated that the percentage of CD3+CD8+ T cells was positively correlated with the levels of HBV DNA, and the CD3+CD4+/CD3+CD8+ ratio was negatively correlated with the level of HBV DNA. Almost no mutations in the HBV DNA sequence were detected in HepG2.2.15 cells co‑cultured with BM‑MSCs, SLCs, or in the two types of cells combined. BM‑MSCs inhibited the expression of HBV DNA and enhanced the clearance of HBV, which may have been mediated by the regulation of the Tc1/Tc2 cell balance and the mode of cytokine secretion to modulate cytokine expression.

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.

De novo hepatitis b prophylaxis with hepatitis B virus vaccine and hepatitis B immunoglobulin in pediatric recipients of core antibody-positive livers

The use of hepatitis B core antibody-positive (HBcAb+) grafts for liver transplantation (LT) has the potential to safely expand the donor pool, as long as proper prophylaxis against de novo hepatitis B (DNHB) is employed. The aim of this study was to characterize the longterm outcome of pediatric LT recipients of HBcAb + liver grafts under a prophylaxis regimen against DNHB using hepatitis B virus (HBV) vaccine and hepatitis B immunoglobulin (HBIG). From June 1996 to February 2013, 49 patients receiving pediatric LT at our center were from HBcAb + donors. Forty-one patients who received DNHB prophylaxis according to our protocol were included in this analysis. Our DNHB prophylaxis protocol consists of HBV vaccine intramuscular injections given intermittently to maintain anti-hepatitis B surface antibody (HBsAb) titers above 100 IU/L. HBIG was also used during the first posttransplant year with a target anti-HBsAb titer level above 200 IU/L. There were 19 boys and 22 girls. Median age was 1.0 year (range, 4 months to 16 years). Median follow-up time was 66 months after transplant. Median annual number of HBV vaccine injections was 0.8 per year (range, 0-1.8 per year). Four patients did not require any HBV vaccine injections during follow-up. One patient with DNHB was encountered during the follow-up period (1/41, 2.4%). DNHB was diagnosed at 3.5 years after transplant, when hepatitis B surface antigen was positive upon routine follow-up serologic testing. Anti-HBsAb titer was 101.5 IU/L at the time. No grafts were lost because of DNHB-related events. Overall survival of the 41 recipients of HBcAb + grafts who received DNHB prophylaxis was 92.3% at 10 years after transplant. In conclusion, longterm prophylaxis against DNHB with HBV vaccine in pediatric LT recipients of HBcAb + grafts was safe and effective in terms of DNHB incidence as well as graft and patient survival.

Hepatitis B and liver transplantation: molecular and clinical features that influence recurrence and outcome

Hepatitis B virus (HBV) continues to be a major cause of morbidity and mortality worldwide. It is estimated that about 350 million people throughout the world are chronically infected with HBV. Some of these people will develop hepatic cirrhosis with decompensation and/or hepatocellular carcinoma. For such patients, liver transplantation may be the only hope for cure or real improvement in quality and quantity of life. Formerly, due to rapidity of recurrence of HBV infection after liver transplantation, usually rapidly progressive, liver transplantation was considered to be contraindicated. This changed dramatically following the demonstration that hepatitis B immune globulin (HBIG), could prevent recurrent HBV infection. HBIG has been the standard of care for the past two decades or so. Recently, with the advent of highly active inhibitors of the ribose nucleic acid polymerase of HBV (entecavir, tenofovir), there has been growing evidence that HBIG needs to be given for shorter lengths of time; indeed, it may no longer be necessary at all. In this review, we describe genetic variants of HBV and past, present, and future prophylaxis of HBV infection during and after liver transplantation. We have reviewed the extant medical literature on the subject of infection with the HBV, placing particular emphasis upon the prevention and treatment of recurrent HBV during and after liver transplantation. For the review, we searched PubMed for all papers on the subject of "hepatitis B virus AND liver transplantation". We describe some of the more clinically relevant and important genetic variations in the HBV. We also describe current practices at our medical centers, provide a summary and analysis of comparative costs for alternative strategies for prevention of recurrent HBV, and pose important still unanswered questions that are in need of answers during the next decade or two. We conclude that it is now rational and cost-effective to decrease and, perhaps, cease altogether, the routine use of HBIG during and following liver transplantation for HBV infection. Here we propose an individualized prophylaxis regimen, based on an integrated approach and risk-assessment.

Prophylaxis of hepatitis B infection in solid organ transplant recipients

Rates of transmission of hepatitis B virus (HBV) infection from organ donors with HBV markers to recipients along with reactivation of HBV during immunosuppression following transplantation have fallen significantly with the advent of hepatitis B immune globulin (HBIg) and effective antiviral therapy. Although the availability of potent antiviral agents and HBIg has highly impacted the survival rate of HBV-infected patients after transplantation, the high cost associated with this practice represents a major financial burden. The availability of potent antivirals with high genetic barrier to resistance and minimal side effects have made it possible to recommend an HBIg-free prophylactic regimen in selected patients with low viral burden prior to transplant. Significant developments over the last two decades in the understanding and treatment of HBV infection necessitate a re-appraisal of the guidelines for prophylaxis of HBV infection in solid organ transplant recipients.

Antenatal lamivudine to reduce perinatal hepatitis B transmission: a cost-effectiveness analysis

OBJECTIVES

This study aimed to determine whether administration of lamivudine to pregnant women with chronic hepatitis B in the third trimester is a cost-effective strategy in preventing perinatal transmission.

STUDY DESIGN

We developed a decision analysis model to compare the cost-effectiveness of 2 management strategies for chronic hepatitis B in pregnancy: (1) expectant management or (2) lamivudine administration in the third trimester. We assumed that lamivudine reduced perinatal transmission by 62%.

RESULTS

Our Markov model demonstrated that lamivudine administration is the dominant strategy. For every 1000 infected pregnant women treated with lamivudine, $337,000 is saved and 314 quality-adjusted life-years are gained. For every 1000 pregnancies with maternal hepatitis B, lamivudine prevents 21 cases of hepatocellular carcinoma and 5 liver transplants in the offspring. The model remained robust in sensitivity analysis.

CONCLUSION

Antenatal lamivudine administration to pregnant patients with hepatitis B is cost-effective, and frequently cost-saving, under a wide range of circumstances.

Substitution of tenofovir/emtricitabine for Hepatitis B immune globulin prevents recurrence of Hepatitis B after liver transplantation

BACKGROUND

Hepatitis B immune globulin (HBIg) with or without nucleos(t)ide analogue (NA) inhibitors has been shown to prevent recurrence of hepatitis B virus (HBV) following orthotopic liver transplantation (OLT). However, the use of HBIg has many disadvantages.

AIMS

The present study was performed to determine if converting patients from HBIg ± NA to combination NA therapy could prevent recurrence of HBV.

METHODS

Twenty-one recipients without evidence of HBV recurrence on HBIg ± NA for ≥ 6 months were enrolled. Patients received their last injection of HBIg at the time they initiated tenofovir disoproxil fumarate/emtricitabine (TDF/FTC; Truvada(®) ) and were followed up for 31.1 ± 9.0 [range 15-47] months.

RESULTS

After 1 year, 3 patients (14%) had detectable HBsAg, one of whom was non-compliant. Two of 3 with recurrence cleared HBsAg by last follow-up on TDF/FTC; the non-compliant patient became HBV DNA-undetectable with re-institution of TDF/FTC. TDF/FTC saved $12,469/year over our standard-of-care, monthly intramuscular HBIg/lamivudine. There was no evidence of a general adverse effect of TDF/FTC on renal function. However, 3 patients developed reversible acute renal failure; on renal biopsy, 1 had possible TDF/FTC-induced acute tubular necrosis.

CONCLUSIONS

Substitution of TDF/FTC for HBIg prevented recurrence of HBV DNA in 100% (20/20) of patients who were compliant with the medication and led to substantial cost savings over HBIg-containing regimens.

The option of HBIG-free prophylaxis against recurrent HBV

Since the early 1990's, hepatitis B immune globulin (HBIG) has been central to the prevention of hepatitis B virus (HBV) recurrence after liver transplantation. When used in combination with oral nucleos(t)ide analogues, HBIG prevents reinfection with HBV in ⩾90% of transplant recipients. While HBIG is highly efficacious, its use is undermined by its high cost. Because of this limitation, there have been many studies of alternative regimens seeking to minimize the dose or duration of HBIG without sacrificing low HBV recurrence rates. Toward that goal, lower dose intramuscular HBIG in combination with oral nucleos(t)ide analogues has been shown to be highly efficacious in preventing disease recurrence and represents a significant cost savings when compared with high dose intravenous administration. The withdrawal of HBIG after a defined course of combination HBIG and oral antivirals has also been shown to be effective, particularly if combination antiviral therapy is used. The ability to achieve undetectable HBV DNA levels pre-transplantation in the majority of patients may contribute to the high efficacy of these HBIG "light" regimens. Additionally, the success of antiviral rescue therapy for those patients who fail prophylaxis and develop recurrent HBV infection post-transplant has provided the impetus to move increasingly towards HBIG-free approaches. New techniques to detect occult HBV in hepatic and extrahepatic sites may allow clinicians to define a subgroup of patients in whom withdrawal of HBIG or all prophylaxis may be applicable.

Current status of liver transplantation for hepatitis B virus

The management of hepatitis B in liver transplantation has evolved significantly over the past 2 decades. Introduction of hepatitis B immune globulin and subsequently nucleos(t)ide analogues has revolutionized transplantation for hepatitis B virus (HBV), increasing survival for patients transplanted for this indication. With the availability of new and potent antivirals for HBV, the need for liver transplant should continue to decrease in the coming years. Moreover, the newer antivirals with high resistance barriers will allow effective long-term viral prophylaxis and therefore, prevention of recurrence.

Posttransplantation prophylaxis with primary high-dose hepatitis B immunoglobulin monotherapy and complementary preemptive antiviral add-on

A considerable proportion of liver transplantation recipients who receive hepatitis B immunoglobulin (HBIG) monotherapy for hepatitis B virus (HBV) prophylaxis develop resistance to HBIG. We retrospectively assessed the efficacy of HBV prophylaxis in 1524 patients who received primary high-dose HBIG monotherapy (n = 1463) or with a preemptive antiviral add-on as secondary combination therapy (n = 61). At a median follow-up time of 57 months, 106 (7.3%) patients receiving HBIG monotherapy experienced HBV recurrence, with a 10-year HBV recurrence rate of 9.8%, compared to none of the patients receiving preemptive combination therapy (P = 0.047). Thirteen patients (12.3%) with HBV recurrence failed antiviral therapy, leading to death or retransplantation. Response rates to rescue therapy before and after use of adefovir/entecavir were 44.4% and 91.8%, respectively. Acute exacerbation was not associated with treatment failure, but required prolonged treatment. Of 84 surviving patients with HBV recurrence, 44 (52.4%) showed no evidence of blood HBV DNA. The Gly145Arg mutation was found in 11 of 15 (73.3%) patients, whereas 25 of 71 (35.2%), 2 of 29 (6.9%), and 4 of 8 (50%) patients were resistant to lamivudine, adefovir, and entecavir, respectively. In conclusion, our finding of a 10-year HBV recurrence rate of 9.8% in patients receiving high-dose HBIG monotherapy indicates that this treatment is effective but requires complementary measures. Strict surveillance following HBIG monotherapy is necessary to enhance responses to rescue antiviral therapy. Preemptive conversion to combination therapy has a complementary role in prophylaxis with primary high-dose HBIG monotherapy, especially for patients at high risk of HBV recurrence.

Posttransplantation hepatitis B prophylaxis with combination oral nucleoside and nucleotide analog therapy

Liver transplant recipients are at risk of developing recurrent hepatitis B after liver transplantation for hepatitis B virus (HBV)-related liver disease. We evaluated the efficacy of a new hepatitis B prophylaxis regimen involving conversion from at least 12 months of HBIg with lamivudine to combination therapy with an oral nucleoside and nucleotide analog. Between June 2008 and May 2010, a total of 61 liver transplant recipients were converted to a combination of a nucleoside and nucleotide analog. The mean (±standard deviation) follow-up time after conversion was 15.0 (±6.1) months. Recurrent HBV occurred in two (3.3%) patients at 3.1 and 16.6 months after HBIg cessation. The overall person time incidence rate for HBV recurrence after HBIg cessation was 2.7 cases per 100 person-years. The estimate of HBV recurrence was 1.7% at 1 year after HBIg cessation. HBIg cessation a minimum of 12 months after liver transplantation with subsequent combination therapy with a nucleoside and nucleotide analog provides effective prophylaxis against recurrent HBV infection. The clinical implications of HBsAg detection without clinical, biochemical or molecular manifestations of recurrent hepatitis B require further study.

Prevention of lamivudine-resistant hepatitis B recurrence after liver transplantation with entecavir plus tenofovir combination therapy and perioperative hepatitis B immunoglobulin only

Combination therapy with antivirals plus hepatitis B immunoglobulin (HBIg) has become the standard treatment for prevention of post-liver transplant hepatitis B virus (HBV) recurrence. However, HBIg therapy is inconvenient and expensive. Alternative therapeutic approaches with modern nucleos(t)ide analogues are limited so far. The present case report describes prevention of HBV recurrence with entecavir and tenofovir. A 48-year-old male patient with hepatitis B-induced decompensated liver cirrhosis initially improved on lamivudine (LAM) until LAM resistance (rtL180M and rtM204V) emerged followed by renewed decompensation. Therefore, tenofovir was added to LAM leading to undetectable HBV DNA (<200 copies/mL). Six months later, low-level viremia (479 copies/mL) was detected. Treatment was escalated to tenofovir plus entecavir. HBV DNA became negative again, and the patient underwent orthotopic liver transplantation. HBIg was administered during transplantation (10,000 IU) and on the second and third postoperative days (total dose 26,000 IU). Subsequently, the anti-hepatitis B surface (HBs) titer rose to 1477 IU/L at day 4 post transplantation. Although HBIg should have been continued, the patient remained on combination therapy with tenofovir plus entecavir only. The anti-HBs titer decreased and became negative 4 months later. However, under continued combination therapy with oral antivirals, HBV DNA and hepatitis B surface antigen remained negative during the entire follow-up of 21 months after liver transplantation. Combination therapy with entecavir plus tenofovir may prevent post-liver transplant hepatitis B recurrence even without HBIg maintenance therapy. This case illustrates that combination oral antiviral therapy might substitute for HBIg as indefinite prophylactic regimen due to profound antiviral efficacy and low risk of viral resistance. Efficacy and safety must be further investigated in randomized controlled trials.

Comparison of different immunoprophylaxis regimens after liver transplantation with hepatitis B core antibody-positive donors: a systematic review

Orthotopic liver transplantation (OLT) recipients without hepatitis B virus (HBV) infection who receive liver grafts from antibody to hepatitis B core antigen-positive [HBcAb(+)], hepatitis B surface antigen-negative [HBsAg(-)] donors have an increased risk of developing de novo hepatitis B infection. We compared the 2 most commonly employed prophylactic regimens-lamivudine (LAM) monotherapy and hepatitis B immunoglobulin (HBIG)+LAM combination therapy-to determine the relative efficacies of these 2 protocols in preventing de novo hepatitis B infection. A comprehensive search of the Cochrane Database of Systematic Reviews, MEDLINE (1966 to June 2009), and bibliographies of retrieved trials was conducted. Eligible studies included OLT recipients who received HBcAb(+) liver grafts and were treated prophylactically with either LAM monotherapy or HBIG+LAM combination therapy. 13 studies were identified as meeting the eligibility criteria. The rates of de novo hepatitis B infection, mortality, and mortality due to de novo hepatitis B infection were assessed. The incidence of de novo hepatitis B infection was 2.7% (n = 73) in patients receiving LAM-only prophylaxis versus 3.6% (n = 110) in patients receiving HBIG+LAM combination therapy. In the HBIG+LAM group, the dose and duration of HBIG therapy were highly variable. The median follow-up time for the LAM monotherapy group was 25.4 months with a range of 14.78 to 27.6 months, whereas the median follow-up time for the LAM+HBIG group was 31.1 months with a range of 15.3 to 38.5 months. The risk of developing de novo hepatitis B infection based on the pretransplant recipient HBV serology in each treatment group could not be calculated because of incomplete data and the limited number of de novo hepatitis B infection cases in the series reviewed. In conclusion, on the basis of these findings, we conclude that published studies have not shown HBIG+LAM combination therapy to be more effective than LAM-only treatment. Nucleoside analogue monotherapy should therefore be considered when one is treating HBV(-) patients who have received liver allografts from HBcAb(+) donors.