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Abstract

  1. Top of page
  2. Abstract
  3. PATIENTS AND METHODS
  4. RESULTS
  5. DISCUSSION
  6. REFERENCES

Hepatitis B immune globulin (HBIG) is routinely used in liver transplantation for hepatitis B virus (HBV)–related liver disease. With potent oral antivirals, HBIG may not be required. We conducted a prospective trial to evaluate living related liver transplantation (LRLT) without HBIG. Eighty-nine patients with HBV-related liver disease underwent LRLT between January 2005 and January 2012. All donors were vaccinated with the HBV vaccine. All patients were given oral antivirals for HBV before transplantation. Patients with HBV DNA levels ≤ 2000 IU/mL were not given HBIG, and patients with HBV DNA levels > 2000 IU/mL were given HBIG. Recurrence was defined as HBV DNA positivity 6 months after transplantation. Seventy-five of the 89 patients who underwent LRLT for HBV-related liver disease were not given HBIG. Nineteen patients received a combination of lamivudine and adefovir, 42 received entecavir, 12 received tenofovir, and 2 received a combination of entecavir and tenofovir. At the last follow-up (median = 21 months, range = 1-83 months), all patients were HBV DNA–negative. Sixty-six patients cleared hepatitis B surface antigen (HBsAg), and 19 patients formed antibody to hepatitis B surface antigen (anti-HBs). The cumulative probabilities of clearing HBsAg were 90% and 92% at 1 and 2 years after transplantation, respectively. Nine patients were HBsAg-positive with undetectable DNA at the last follow-up. The recurrence rate in our series was 8% (6/75). Five of these 6 patients had stopped taking oral antivirals, and 1 had entecavir resistance. All recurrences were salvaged with changes in the oral antivirals. The actuarial probability of survival in this cohort was 73.7% at 83 months. There was no mortality due to HBV recurrence. In conclusion, HBV prophylaxis with oral antivirals and without HBIG is safe and effective in LRLT. A majority of the patients will clear HBsAg, and some will develop anti-HBs antibodies. Liver Transpl 19:1030–1035, 2013. © 2013 AASLD.

Abbreviations
anti-HBs

antibody to hepatitis B surface antigen

HBIG

hepatitis B immune globulin

HBsAg

hepatitis B surface antigen

HBV

hepatitis B virus

LRLT

living related liver transplantation

Patients undergoing transplantation for hepatitis B virus (HBV) cirrhosis require prophylactic antiviral therapy. The risk of HBV reinfection after liver transplantation without prophylaxis is approximately 80%, and the rate is higher for patients with high HBV DNA levels at the time of transplantation.[1, 2] The current recommendation for HBV prophylaxis is a combination of a nucleoside/tide analogue and high-dose hepatitis B immune globulin (HBIG) for life.[3] Recently, low-dose HBIG in combination with lamivudine has been shown to be equally efficacious.[4] The combination of HBIG with antivirals (lamivudine and adefovir) has reduced the risk of reinfection to 10% during the first 2 years after transplantation.[5-7] However, with the advent of newer, more effective oral antivirals with lower resistance rates, the role of HBIG in the transplant setting needs to be re-evaluated.[8]

There are published data on the transfer of immunity from HBV-immunized donors to recipients of liver transplantation for HBV-related indications.[9, 10] Living donor liver transplantation offers a unique opportunity for vaccinating donors before transplantation. This transfer of adoptive immunity from vaccinated donors to recipients may also eliminate the need for HBIG after liver transplantation in this population.

We report a prospective trial evaluating outcomes after living related liver transplantation (LRLT) without HBIG prophylaxis. We performed this study to evaluate the efficacy of oral antivirals alone in the prevention of HBV reinfection with an HBIG-free protocol and to determine the hepatitis B surface antigen (HbsAg) seroconversion rate and antibody to hepatitis B surface antigen (anti-HBs) production in this population.

PATIENTS AND METHODS

  1. Top of page
  2. Abstract
  3. PATIENTS AND METHODS
  4. RESULTS
  5. DISCUSSION
  6. REFERENCES

Study Design

All patients who underwent LRLT for HBV-related liver disease at our center between January 2005 and January 2012 were prospectively included in this study. All patients were followed until October 2012 or death. The relationships of donors and recipients were recorded for any possible influence on the outcome. The study was approved by the hospital ethical commeittee.

Antiviral Therapy

All patients were started on an oral nucleoside/nucleotide according to their previous history. During the initial days of the study, all patients received a combination of lamivudine and adefovir. With the availability of new antiviral drugs, patients received entecavir preferentially, and those with lamivudine resistance were given tenofovir. Those with both lamivudine and adefovir resistance were given a combination of entecavir and tenofovir. All recipients received oral antivirals before transplantation to reduce HBV DNA levels to <2000 IU/mL (except for those with acute liver failure). Those who either were HBV DNA–negative or had levels < 2000 IU/mL at the time of transplantation were not given HBIG. Patients with HBV DNA counts > 2000 IU/mL were given low-dose intramuscular HBIG (800 IU from day 0 to day 7 after transplantation and then monthly until 2 successive HBV DNA counts were negative). The patients were continued after transplantation on the same oral antiviral regimen given in the pretransplant period.

Follow-Up

All patients with HBV DNA counts > 2000 IU/mL underwent testing monthly after transplantation until 2 consecutive values were negative and subsequently every 6 months as the others who underwent HBV DNA testing. HBsAg was measured monthly until 2 consecutive samples were negative and then every 6 months. Anti-HBs antibody titers were measured 6 months after transplantation. If a patient was negative for anti-HBs antibodies, he was given a course of HBV vaccination, and his titers were checked 1 month after the completion of his vaccination. A recurrent HBV infection was defined as the reappearance of HBsAg or HBV DNA after transplantation after initial seroclearance/DNA negativity.

Donor Vaccination

All donors were tested for HBV immunity, and a booster dose was given at least 15 days before transplantation. Vaccination was performed with a single intramuscular injection 2 mL deep. Donors for patients with acute liver failure were vaccinated when they arrived at the hospital.

Immunosuppression

All patients received triple immunosuppression (a calcineurin inhibitor, mycophenolate, and a steroid) initially. Tacrolimus was used in 90% of the recipients with trough levels maintained between 5 and 8 ng/mL. Cyclosporine was used in children < 3 years old and when tacrolimus was not tolerated. The mycophenolate dose was 500 mg twice a day for recipients ≤ 70 kg and 750 mg twice a day for recipients > 70 kg. Steroids were tapered off by the end of 3 months for most patients. Rejection episodes were treated with 500 mg of methylprednisolone daily for 3 days, and this was followed by a tapering dose of prednisolone (from 100 to 20 mg/day over the course of 5 days). No patient received antibody induction therapy.

Diagnostic Assays

HBsAg and anti-HBs antibodies were detected with an enzyme-linked immunosorbent assay technique (VIDAS HBsAg Ultra and VIDAS anti-HBs Total Quick, BioMerieux, France). HBV DNA was determined with a polymerase chain reaction method (COBAS TaqMan assay, Roche Molecular Systems, Branchburg, NJ). Patients were monitored via HBV DNA counts every month until there were 2 successive undetectable values and then every 6 months. HbsAg was tested monthly until negative findings and then every 6 months. The anti-HBs antibody titer was checked 6 months after transplantation, after attempts at vaccination, and subsequently at 6-month intervals.

Statistical Analysis

The statistical analysis was performed with SPSS 20 (SPSS, Inc., Chicago, IL). Categorical variables were compared with the chi-square test or Fisher's exact test. Continuous variables were analyzed with the Mann-Whitney U test. The cumulative incidence of HBsAg clearance was calculated with the Kaplan-Meier method, and comparisons were made with the log-rank test. The actuarial probability of survival was calculated with the Kaplan-Meier method. A P value less than 0.05 was considered statistically significant.

RESULTS

  1. Top of page
  2. Abstract
  3. PATIENTS AND METHODS
  4. RESULTS
  5. DISCUSSION
  6. REFERENCES

Between January 2005 and January 2012, LRLT was performed 651 times at our center. Eighty-nine patients underwent LRLT for HBV-related liver disease. Fourteen of the 89 patients received perioperative HBIG because their baseline HBV DNA counts were >2000 IU/mL, and they were excluded from the final analysis.

Seventy-five patients underwent liver transplantation without the use of perioperative HBIG. The baseline HBV DNA count before transplantation was negative for 57 patients. Eighteen of these patients had positive HBV DNA counts (but <2000 IU/mL) before transplantation (median = 258 IU/mL, range = 15-1500 IU/mL). Sixteen of the 75 patients had associated hepatocellular carcinoma. The baseline demographic data are presented in Table 1. Indications for transplantation are listed in Table 2. Acute liver failure was the transplant indication for 3 patients. All patients (except for those undergoing transplantation for acute liver failure) were on oral antivirals for at least 1 month before transplantation. The details for the oral antivirals are presented in Table 3.

Table 1. Demographic Characteristics of the Patients (n = 75)
Median age (years)47 (range = 17–69)
Sex: male/female (n/n)66/9
Median Model for End-Stage Liver Disease score19 (range = 8–40)
Child score: A/B/C (n/n/n)2/24/49
HBV DNA before transplantation: positive/negative (n/n)18/57
Median follow-up (months)21 (range = 1–83 months)
Table 2. Indications for Liver Transplantation (n = 75)
Indicationn
  1. a

    Not exclusive of decompensated cirrhosis.

Decompensated cirrhosis68
Acute liver failure3
Acute-on-chronic liver failure2
Hepatocellular carcinomaa16
Table 3. Oral Antiviral Therapy
Oral Antiviraln
Lamivudine + adefovir19
Entecavir42
Tenofovir12
Entecavir + tenofovir2

The relationships of the donors to the recipients were recorded. A majority of the donors were close relatives who had lived together with the recipients in the same household (20 sons or daughters, 19 brothers or sisters, 10 wives, 11 first cousins, 2 mothers, 7 nephews or nieces, and 6 distant relatives).

Recurrence of HBV

Seventy-five patients with HBV-related liver disease underwent liver transplantation without perioperative HBIG. Fifty-seven patients were HBV DNA–negative before transplantation and remained negative after transplantation. The 18 patients who were HBV DNA–positive before transplantation achieved HBV DNA negativity within the first 3 months after transplantation (range = 15 days to 3 months).

HBV DNA reappeared in the blood of 6 patients after the clearance of HBV DNA as well as HBsAg. Five of these 6 patients had stopped taking oral antivirals on their own. One patient had developed resistance to entecavir. All these patients were salvaged by changes in their oral antivirals without the use of HBIG. All these patients with recurrence were HBV DNA–negative at the last follow-up after they changed their antiviral therapy. Among the 6 patients in whom HBsAg and HBV DNA reappeared after antiviral therapy was stopped, 3 experienced HBsAg clearance again after the re-initiation of oral antivirals. The recurrence rate in our series for patients undergoing transplantation without HBIG was 8% (6/75).

Sixty-six of the 75 patients had cleared HBsAg by the last follow-up. The median time to the clearance of HBsAg was 3 months (range = 1-12 months). Nine patients never experienced HBsAg clearance but were negative for HBV DNA at the last follow-up. The cumulative probabilities of HBsAg clearance after transplantation were 90% and 92% at 1 and 2 years after transplantation, respectively (Fig. 1). Two of the patients who were positive for HBV DNA before transplantation (n = 18) were HBsAg-positive at the last follow-up. Seven of the 57 patients who were negative for HBV DNA before transplantation had detectable HBsAg at the last follow-up. There was no difference in the rate of HBsAg loss between those who were HBV DNA–positive and those who were negative at the time of transplantation (P = 1.01, Fisher's exact test).

image

Figure 1. Cumulative probability of the clearance of HBsAg after transplantation.

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Survival

Overall, 18 of the 75 patients died (survival rate = 76%) with a median follow-up of 21 months (range = 1-83 months). Nine patients died within the first 2 months after transplantation: 8 were HBV DNA–negative before transplantation, and 1 had a pretransplant HBV DNA level of 220 IU/mL. None of the 18 deaths were due to the recurrence of HBV disease because all patients were HBV DNA–negative at the time of death. Twelve of these patients underwent liver biopsy either before or after their demise, and none showed evidence of HBV recurrence. The causes of death are listed in Table 4. The actuarial probability of survival in this cohort was 73.7% at 83 months (Kaplan-Meier analysis; Fig. 2). Fifteen of the 57 patients who were negative for HBV DNA before transplantation died. There were 3 deaths among the 18 patients positive for HBV DNA before transplantation. There was no difference in mortality between patients who were HBV DNA–positive and patients who were negative before transplantation (P = 0.53, Fisher's exact test).

image

Figure 2. Actuarial probability of survival for liver transplant patients without HBIG.

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Table 4. Causes of Death
Cause of Deathn
Cardiac (myocardial infarction or left ventricular dysfunction)2
Chronic rejection2
Hepatocellular carcinoma recurrence3
Intracranial bleeding1
Necrotizing fasciitis1
Pancreatitis1
Primary nonfunction1
Fungal sepsis1
Bacterial sepsis2
Hepatic Artery Thrombosis1
Intrahepatic bleed (Post biopsy)1
Bile leak/sepsis2
Total18

Follow-Up

Oral antivirals were given to all patients (except for those undergoing transplantation for acute liver failure) for at least 1 month before transplantation (Table 3). Nineteen patients were given a combination of lamivudine and adefovir. With the introduction of newer antiviral drugs, entecavir and tenofovir were used. Forty-two patients were on entecavir, 12 were given tenofovir, and 2 patients received a combination of entecavir and tenofovir because they had documented resistance to both lamivudine and adefovir. Six patients experienced a recurrence of their HBV infection, which was documented by the reappearance of HBV DNA in their serum. Five of these 6 patients had stopped taking oral antiviral drugs, and 1 patient on entecavir had developed HBV DNA positivity. All patients with recurrence were salvaged with changes in the oral antiviral drugs. All patients were negative for HBV DNA at the last follow-up. The probability of recurrence was 8% (6/75) according to an intention-to-treat analysis.

All patients were monitored for the development of anti-HBs antibody titers 6 months after transplantation and subsequently at 6-month intervals. Five patients developed anti-HBs antibody titers > 100 mIU/mL (range = 105-1050 mIU/mL). Another 14 patients had titers between 10 and 100 mIU/mL (range = 10-58 mIU/mL). Anti-HBs antibodies were undetectable (<10 mIU/mL) for all others. Thus, only part of our cohort (19/75) developed significant antibody titers. Fourteen of the 19 patients who developed anti-HBs antibody titers > 10 mIU/mL had these titers 6 months after transplantation. The other 5 patients developed antibodies after attempts at HBV vaccination starting 6 months after transplantation. All patients who had positive antibody titers maintained them for a median follow-up period of 17 months (range = 6-70 months). There was no correlation between preoperative HBV DNA and the development of anti-HBs antibodies after transplantation (P = 0.53, Fisher's exact test).

Sixteen patients had hepatocellular carcinoma before transplantation. Five of these patients experienced a recurrence of their hepatocellular carcinoma; 2 patients had an early recurrence at 3 and 5 months. Both of these patients experienced recurrence in the transplanted liver. Three patients had a recurrence of hepatocellular carcinoma (bony metastasis) 12 to 18 months after transplantation

DISCUSSION

  1. Top of page
  2. Abstract
  3. PATIENTS AND METHODS
  4. RESULTS
  5. DISCUSSION
  6. REFERENCES

The current recommendations for prophylaxis for recurrent HBV infections after transplantation are based on old data on the combination of lamivudine and HBIG.[3] HBIG has been used in combination with lamivudine because of the low genetic barrier and the high incidence of resistance to lamivudine. A combination of lamivudine and adefovir has been used successfully to eliminate the use of HBIG after transplantation.[7, 11] With the advent of more potent oral antivirals, the need for HBIG in the posttransplant setting needs to be reevaluated.[12, 13] Recently, a study showed that HBIG may not be required after transplantation with the use of entecavir.[8, 9] With the transfer of adoptive immunity from HBV-vaccinated/immune donors, HBV recipients have been shown to clear HBsAg and form anti-HBs antibodies without the use of HBIG.[8, 9] We are reporting a prospective trial of liver transplantation for patients with HBV-related disease who were managed with oral antivirals alone.

During the initial days of the trial, a combination of lamivudine and adefovir was used for all patients. With the introduction of entecavir and tenofovir into the Indian subcontinent, these became the preferred drugs, and the use of the lamivudine-adefovir combination was discontinued. Entecavir was the oral antiviral used in treatment-naive patients before transplantation. In patients with a previous history of lamivudine exposure, tenofovir was preferred. However, there was no difference in recurrence rates between patients on different oral antiviral drugs.

Despite the complete omission of HBIG from our patients who achieved preoperative HBV DNA levels < 2000 IU/mL, the rate of HBV infection recurrence was 1.3% (1/75) for those who were treatment-compliant. Another 5 patients who developed recurrence had stopped their oral antiviral prophylaxis. Only 1 patient on therapy developed resistance to entecavir. All patients with recurrence were successfully salvaged with changes in their oral antivirals. Therefore, according to a per-protocol analysis, the use of oral antivirals alone was associated with a very low risk of recurrence (1.3%). All the patients were HBV DNA–negative at the last follow-up.

All donors (except for 3 donors who donated for patients with acute liver failure) were vaccinated against HBV at least 15 days before transplantation with a double-dose vaccine. The recipients were monitored for the clearance of HBsAg and the appearance of anti-HBs antibodies. The majority of the patients cleared HBsAg after transplantation without any HBIG (66/75). All those who cleared HbsAg did so within 1 year of transplantation (range = 1-12 months). The cumulative probability of antigen clearance was 90% 1 year after transplantation. Some of these patients also formed anti-HBs antibodies (19/66). Five patients developed antibody titers > 100 mIU/mL. The likelihood of HBsAg clearance in a patient with chronic HBV on oral antivirals is 5% over 5 to 7 years. In a post–liver transplant patient who is immunosuppressed, the probability of HBsAg clearance without HBIG should be even lower (although data are lacking in this regard). The actuarial probability of HBsAg clearance in our cohort was 92% at 2 years. We attribute this high rate of clearance to the transfer of immunity from the vaccinated donors to the recipients because we did not use HBIG in any of these patients. This suggests that a transfer of immunity from the donor to the recipient is possible. The clearance of surface antigens and the formation of antibodies did not depend on the preoperative HBV DNA status of the recipients because the rates were similar for those who were positive and those who were negative for HBV DNA before transplantation.

In our study, the actuarial probability of survival was 73.7% during a follow-up period of 83 months. The causes of death are detailed in Table 4. None of the deaths were due to HBV recurrence after transplantation. The HBV DNA levels before transplantation did not affect mortality after transplantation in this cohort. The survival rate of our cohort is similar to the rates in previously reported series using a combination of HBIG and oral antivirals. In 2 large multicenter studies from the United States and Europe, the 5-year survival rate for patients undergoing transplantation for HBV-related liver disease was approximately 75% in a deceased donor liver transplantation setting.[14, 15] The only published trial on oral antivirals alone in an LRLT setting reported 5 deaths among 80 patients during a follow-up period of 26 months (range = 5-40 months).[8] Hence, the long-term survival rate without HBIG in this study is similar to the previously reported survival rates for recipients of liver transplantation for HBV-related indications with or without the use of HBIG. We conclude that in the era of newer antivirals, an HBIG-free regimen is as safe and effective as an HBIG and oral antiviral combination.

Although most of the patients experienced HBsAg clearance after transplantation in this cohort, the clearance of HBsAg and even the formation of anti-HBs antibodies did not seem to confer immunity against HBV. All the patients who stopped taking oral antivirals were negative for HBsAg at the time of their default. All 5 patients experienced a reappearance of HBsAg as well as HBV DNA within a few months of stopping. The mechanisms and implications of the loss of surface antigen and the formation of antibodies need further study. One possibility that particularly needs further investigation is the role of related donors in HBV immunity. Most of the donors in our study were close relatives who had stayed together with the recipients in the same household. This raises the possibility that many of these donors would have been exposed to HBV and developed immunity. This immunity could then have been transmitted to the recipients via the liver grafts.

In conclusion, HBV prophylaxis with oral antivirals and without HBIG is safe and effective in an LRLT setting. A majority of the patients will clear HBsAg after transplantation. Some of the patients will develop anti-HBs antibodies.

REFERENCES

  1. Top of page
  2. Abstract
  3. PATIENTS AND METHODS
  4. RESULTS
  5. DISCUSSION
  6. REFERENCES