Hepatitis B immune globulin to prevent hepatitis B virus graft reinfection following liver transplantation: a concise review

Viral load at the time of liver transplantation and risk of hepatitis B virus recurrence

Hepatitis B virus (HBV) recurrence after liver transplantation is significantly reduced by prophylaxis with hepatitis B immune globulins (HBIG) or antiviral drugs in nonreplicating patients and by the combination of both drugs in replicating patients. However, the load of HBV DNA, which defines replicating status in patients undergoing liver transplantation, remains unclear. This study analyzes the correlation between the viral load, tested with a single amplified assay, at the time of liver transplantation, and the risk of hepatitis B recurrence in 177 HBV carriers who underwent transplantation in a single center from 1990 to 2002. Overall, HBV relapsed after surgery in 15 patients (8.5%) with a 5- and 8-year actuarial rate of recurrence of 8% and 21%, respectively. After liver transplantation hepatitis B recurred in 9% of 98 selected subjects treated only with immune globulins and in 8% of 79 viremic patients who received immune globulins and lamivudine (P = NS). A linear correlation was observed between recurrence and viral load at the time of surgery. In transplant patients with HBV DNA higher than 100,000 copies/mL, 200-99,999 copies/mL, and DNA undetectable by amplified assay, hepatitis B recurred in 50%, 7.5%, and 0% of patients, respectively. Overall, a viral load higher than 100,000 copies/mL at the time of liver transplantation was significantly associated with hepatitis B recurrence (P = .0003). In conclusion, spontaneous or antiviral-induced HBV DNA viral load at the time of surgery classifies the risk of HBV recurrence after liver transplantation and indicates the best prophylaxis strategy.

HBV vaccination in liver transplant recipients: not an effective strategy in the prophylaxis of HBV recurrence

Anti-HBs immunoglobulins (HBIG) and lamivudine are main options to prevent hepatitis B virus (HBV) reinfection after liver transplantation. Although they are very effective, development of mutant viruses and high cost of treatment are main limitations for their application. Additionally there is an uncertainity for the duration of that prophylaxis regimen and its mostly applied indefinitely. Recently, post-transplant HBV vaccination is reported to be a cheaper alternative prophylaksis strategy, that enables discontinuation of HBIG. To investigate the efficacy of HBV vaccination in patients transplanted for HBV cirrhosis, we administered double course of double dose recombinant HBV vaccine (Genhavac B; containing HBV pre-S1, pre-S2, and S gene products). Vaccination has been started 1 month after HBIg discontinuation, and lamivudine (100 mg/day) was given throughout the study. The first cycle consisted of 0, 1- and 6-month schedule, and, in nonresponders, second cycle 0, 1-, 2-month schedule. Fourteen patients included into the study. Only one patient seroconverted (an anti-HBs titre of 37 IU/L) after the first cycle. No other patient responded to second cycle. HBV vaccination in the post-transplantation setting does not seems like an effective strategy in the prophylaxis of HBV recurrence.

Treatment of hepatitis B and C after liver transplantation. Part 1, hepatitis B

The outcome of OLT for HBV-related liver disease is dependent on the prevention of allograft re-infection. Over the past decade, major advances have been made in the management of HBV transplant candidates. The advent of long-term hepatitis B immune globulin (HBIG) administration as a prophylaxis against HBV recurrence, and the introduction of new antiviral agents against HBV infection, such as lamivudine (LAM), were a major breakthrough in the management of these patients. Results of OLT for HBV infection are similar to those achieved with other indications. Pre-OLT antiviral treatment such as LAM can suppress HBV replication before OLT and thus decrease the risk of re-infection of the graft. Combination prophylaxis with LAM and HBIG after transplantation highly effectively reduces the rate of HBV re-infection, even in HBV replicative cirrhotic patients. The optimal HBIG protocol in the LAM era is yet to be defined: dosing of HBIG, routes of administration, and possibility of stopping HBIG. Several antiviral drugs have been developed for the management of HBV infection on the graft, so outcome is currently good.

Management of HBV Infection in Liver Transplantation Patients

In the absence of preventative therapy, reinfection of allografts with hepatitis B virus (HBV) after orthotopic liver transplantation (OLT) resulted in dismal allograft and patient survival. Major advances in the management of HBV-infected recipients of OLT during the past 15 years have steadily reduced the rate of reinfection, resulting in improved outcomes. Initially, long-term use of hepatitis B immune globulin (HBIG) as a source of anti-HBs antibodies was effective in preventing or delaying reinfection. Lamivudine monotherapy made it possible to suppress HBV replication prior to OLT, markedly decreasing the risk of reinfection. Although lamivudine monotherapy used before and after OLT could prevent reinfection, its effectiveness was limited by progressive development of lamivudine-resistant mutant infections. Combination therapy with HBIG and lamivudine after OLT reduced both HBV recurrence and the risk of lamivudine resistance even in patients with active HBV replication. Introduction of adefovir provided a safe, alternative oral antiviral able to treat effectively lamivudine-resistant mutants HBV. Available strategies to prevent reinfection have resulted in OLT outcomes for HBV-infected patients comparable to those for patients transplanted for non-HBV indications. In the future, combination therapies of HBIG and both nucleoside and/or nucleotide agents will undoubtedly be optimized. Development of new drugs to treat HBV will increase opportunities to combine agents to enhance safety, efficacy and prevent emergence of HBV escape mutants. New vaccines and adjuvants may make it possible to generate anti-HBs in immunosuppressed patients, eliminating the need for HBIG.

Genotype prevalence, viral load and outcome of hepatitis B virus precore mutant infection in stable patients and in patients after liver transplantation

OBJECTIVE

The precore mutant is detectable in most Israeli patients with persistent hepatitis B virus (HBV) infection. The aim of this study was to determine the prevalence of HBV genotypes, viral load and outcome of precore mutant infection in stable patients and in patients after liver transplantation.

METHODS

The prevalence of HBV genotype and viral load were investigated in 81 patients with HBV precore mutant infection. Of these, 50 patients (40 males, 10 females; mean age 43.4 +/- 11.0 yr) underwent liver transplantation and were serum HBV DNA-negative by hybridization at the time of transplantation. Patients received long-term HBV immunoprophylaxis and immunosuppression, and lamivudine in cases of graft HBV recurrence. The remaining 31 patients were stable, with serum anti-HBe-positivity. Genotypes were tested by restriction fragment length polymorphism of an S gene amplicon. Precore mutations were studied with an INNO-LiPA probe assay.

RESULTS

Follow-up was 46.6 +/- 37.7 months. Most of the transplanted group was of Middle Eastern origin (53.6%); the remainder were from Eastern Europe (21.4%), Western Europe and the USA (10.8%), Africa (7.1%), and Asia (7.1%). In the transplanted group, the pre-transplant HBV genotype D was the most prevalent (96%), while genotype A was found in only 4%. Eleven patients (22%) developed recurrent HBV infection post-transplantation. There were no differences in genotype distribution between patients with graft reinfection or lamivudine resistance and patients without recurrence. Mean viral load at recurrence was 148.4 x 10(6) +/- 60.4 x 10(6) copies/mL. The stable group had a similar origin and HBV genotype prevalence, but a lower mean viral load of 12.4 x 10(6) +/- 29.4 x 10(6) copies/mL (p = 0.007). The prevalence of mutations at the precore region and codon 28 was similar in both groups.

CONCLUSIONS

The chronic precore mutant HBV-infected patients were characterized as follows: (i) genotype D was the most frequent genotype, (ii) the HBV genotype distribution was similar in patients with stable infection and after liver transplantation, (iii) viral load at recurrence was significantly higher than in stable infection, and (iv) HBV genotype was unrelated to the development of recurrence or lamivudine resistance in the tested population.

Evolving strategies to prevent HBV recurrence

1. Long-term prophylaxis with hepatitis B immune globulin (HBIG) significantly reduces the risk for hepatitis B virus (HBV) recurrence and increases survival. Patients with HBV cirrhosis and / or positive HBV DNA at the time of transplantation have a high risk for recurrence despite HBIG prophylaxis. 2. Pre-orthotopic liver transplantation (OLT) antiviral treatment using lamivudine (LAM) can suppress HBV replication before transplantation and may induce clinical improvement in a subset of patients. Adefovir dipivoxil (ADV) may serve as "rescue" therapy for patients with LAM resistance; its place as first-line therapy requires further evaluation. 3. Combination prophylaxis with LAM and HBIG prevents HBV recurrence in 90% to 100% of patients who undergo transplantation for hepatitis B. The optimal HBIG protocol in the "nucleoside-nucleotide analog era" remains to be determined. The place of ADV or LAM as first-line posttransplant antiviral therapy in combination with HBIG requires further studies. 4. Future research should test new protocols using lower HBIG doses given intravenously (IV) or intramuscularly (IM) alone or in combination with antiviral agents and identify patients in whom HBIG prophylaxis can be stopped safely or replaced by antiviral agents or vaccination.

Low-dose hepatitis B immunoglobulin given "on demand" in combination with lamivudine: a highly cost-effective approach to prevent recurrent hepatitis B virus infection in the long-term follow-up after liver transplantation

BACKGROUND

Cost of long-term prophylaxis with high-dose human hepatitis B immune globulin (HBIg) after liver transplantation is extremely high. The aim of the present study was to assess consumption rates of high (5,000 IU) and low (2,000 IU) doses of HBIg given intravenously "on demand", and determine their cost-effectiveness compared with conventional fixed monthly schedules.

METHODS

The study included 11 male patients (mean age 53 years) who received transplants for hepatitis B virus (HBV)-related cirrhosis 29 to 96 months earlier, all receiving lamivudine (100 mg/day) prophylaxis. Each patient received three consecutive intravenous infusions of 5,000 IU HBIg, followed by three 2,000 IU infusions. HBIg consumption was assessed by serial measurement of serum hepatitis B surface antibody (HBsAb) titer at 2-week intervals. HBIg was readministered only when HBsAb titers dropped below 70 IU/L (i.e., "on demand").

RESULTS

Mean HBsAb peak titers after high and low HBIg doses were 1,641 +/- 385 and 848 +/- 216 IU/L, respectively (P <0.0001). Mean time to reach an HBsAb titer less than 70 IU/L was 79.5 +/- 38.2 days versus 61.6 +/- 32.1 days, respectively (P =NS). Interindividual variation coefficients were 23 +/- 18% and 32 +/- 26% (5,000 IU and 2,000 IU, respectively). Using the on demand approach, maintenance of a protective anti-HBs titer required an average number of 4.0 (5,000 IU) and 5.6 (2,000 IU) HBIg administrations per year, respectively (P =NS).

CONCLUSIONS

Individual HBIg consumption profiles are highly variable. A low-dose (2,000 IU) on demand HBIg administration schedule is highly cost-effective and provides more than 50% savings compared with conventional high-dose monthly schedules.

Hepatitis B vaccines

Yeast-derived hepatitis B vaccines, containing the small HBV envelope protein SHBAg, are immunogenic, safe and cost-effective in prevention of hepatitis B virus infection in neonates, children and adults. Newly developed pre-S/S hepatitis B vaccines may play a role in inducing fast and augmented seroconversion rates in special risk groups.

Evolution of hepatitis B virus sequence from a liver transplant recipient with rapid breakthrough despite hepatitis B immune globulin prophylaxis and lamivudine therapy

Recurrent hepatitis B virus (HBV) infection after liver transplantation can be prevented by prophylactic hepatitis B immune globulin (HBIG) and lamivudine therapy. However, reinfection may still occur due to the emergence of immune escape mutants and mutants of the YMDD motif. The full spectrum of mutations within the HBV genome during recurrent HBV infection remains to be documented. In this study, serial HBV isolates were characterized from a patient with lamivudine resistance prior to liver transplantation who developed recurrent HBV infection within 2 months of transplantation despite a high dose of HBIG and lamivudine therapy. Sequence analysis of full-length viral genome before transplantation revealed many point mutations as compared with a wild-type genotype C sequence, including the T1753G/A1762T/G1764A triple mutation in the basal core promoter and the G1896A nonsense mutation in the precore region. After transplantation and therapy, several point mutations in the HBV genome emerged or became dominant. These mutations caused L426I/L526M/M550I triple mutation (equivalent to L428I/L528M/M552I in previous reports) in the polymerase, and D144E mutation in the "a" determinant of HBsAg. Transfection experiments revealed that the D144E mutation reduced HBsAg affinity to anti-HBs, confirming its active role for immune escape. Our study suggests that mutations in the HBsAg (D144E) and the polymerase (L426I/L526M/M550I) of HBV genome may be responsible for viral breakthrough despite HBIG prophylaxis and lamivudine therapy.

Living donor liver transplantation for hepatitis B cirrhosis

The living donor liver transplantation (LDLT) experience for patients with hepatitis B virus (HBV) infection is still limited. Because LDLT can be performed electively, it can provide an appropriate length of time to reduce HBV DNA levels before the operation. This study aims to examine the feasibility of our protocol for preventing HBV reinfection after LDLT. Of 20 patients analyzed, 15 patients had detectable serum HBV DNA when referred to our hospital. Thirteen patients had hepatocellular carcinoma. All patients were treated with lamivudine (100 mg/d) before LDLT. After LDLT, hepatitis B immunoglobulin (HBIG) was administered to maintain serum antibody to hepatitis B surface antigen titers at greater than 1,000 IU/mL for 1 year and 200 IU/mL thereafter. Lamivudine was not administered postoperatively, except for three patients with detectable serum HBV DNA just before LDLT. All patients survived the operation. One patient died 229 days after LDLT of carcinoma recurrence. In the other 19 patients, liver function has remained normal and no viral relapse occurred postoperatively during a median follow-up of 19 months. Perioperative use of lamivudine and indefinite HBIG administration in the postoperative period might be a rational strategy for preventing HBV reinfection after LDLT.

Immunization with an adjuvant hepatitis B vaccine after liver transplantation for hepatitis B-related disease

Patients who undergo transplantation for hepatitis B virus (HBV)-related diseases are treated indefinitely with hepatitis B hyperimmunoglobulin (HBIG) to prevent endogenous HBV reinfection of the graft. Active immunization with standard hepatitis B vaccines in these patients has recently been reported with conflicting results. Two groups of 10 liver transplant recipients on continuous HBIG substitution who were hepatitis B surface antigen (HBsAg) positive and HBV DNA negative before transplantation were immunized in a phase I study with different concentrations of hepatitis B s antigen formulated with the new adjuvants 3-deacylated monophosphoryl lipid A (MPL) and Quillaja saponaria (QS21) (group I/vaccine A: 20 microg HBsAg, 50 microg MPL, 50 microg QS21; group II/vaccine B: 100 microg HBsAg, 100 microg MPL, 100 microg QS21). Participants remained on HBIG prophylaxis and were vaccinated at weeks 0, 2, 4, 16, and 18. They received 3 additional doses of vaccine B at bimonthly intervals if they did not reach an antibody titer against hepatitis B surface antigen (anti-HBs) greater than 500 IU/L. Sixteen (8 in each group) of 20 patients (80%) responded (group I: median, 7,293 IU/L; range, 721-45,811 IU/L anti-HBs; group II: median, 44,549 IU/L; range, 900-83,121 IU/L anti-HBs) and discontinued HBIG. They were followed up for a median of 13.5 months (range, 6-22 months). The vaccine was well tolerated. In conclusion, most patients immunized with the new vaccine can stop HBIG immunoprophylaxis for a substantial, yet to be determined period of time.

Immunization with an adjuvant hepatitis B vaccine after liver transplantation for hepatitis B-related disease

Patients who undergo transplantation for hepatitis B virus (HBV)-related diseases are treated indefinitely with hepatitis B hyperimmunoglobulin (HBIG) to prevent endogenous HBV reinfection of the graft. Active immunization with standard hepatitis B vaccines in these patients has recently been reported with conflicting results. Two groups of 10 liver transplant recipients on continuous HBIG substitution who were hepatitis B surface antigen (HBsAg) positive and HBV DNA negative before transplantation were immunized in a phase I study with different concentrations of hepatitis B s antigen formulated with the new adjuvants 3-deacylated monophosphoryl lipid A (MPL) and Quillaja saponaria (QS21) (group I/vaccine A: 20 microg HBsAg, 50 microg MPL, 50 microg QS21; group II/vaccine B: 100 microg HBsAg, 100 microg MPL, 100 microg QS21). Participants remained on HBIG prophylaxis and were vaccinated at weeks 0, 2, 4, 16, and 18. They received 3 additional doses of vaccine B at bimonthly intervals if they did not reach an antibody titer against hepatitis B surface antigen (anti-HBs) greater than 500 IU/L. Sixteen (8 in each group) of 20 patients (80%) responded (group I: median, 7,293 IU/L; range, 721-45,811 IU/L anti-HBs; group II: median, 44,549 IU/L; range, 900-83,121 IU/L anti-HBs) and discontinued HBIG. They were followed up for a median of 13.5 months (range, 6-22 months). The vaccine was well tolerated. In conclusion, most patients immunized with the new vaccine can stop HBIG immunoprophylaxis for a substantial, yet to be determined period of time.

Combined lamivudine and hepatitis B immunoglobulin for the prevention of hepatitis B recurrence after liver transplantation: long-term results

For the prevention of recurrent hepatitis B virus (HBV) infection after liver transplantation (LT), the efficacy of hepatitis B immunoglobulin (HBIg) has been largely demonstrated. The aim of this pilot study was to determine if the addition of lamivudine to HBIg in the prevention of HBV recurrence after LT could be more effective. Sixty HBsAg-positive/HBV DNA-negative patients underwent LT from October 1990 to December 2001. All 60 patients received intravenous HBIg to maintain serum anti-HB levels above 500 IU/L, indefinitely. Since 1997, 17 patients have received combined oral lamivudine (150 mg/day) and HBIg, and were compared with the historical cohort of 43 patients. In the historical control group, the recurrence rate was 10/43 (23%) after a 98-month median follow-up. Five patients died from HBV-related liver disease. After a 30-month median follow-up, none of the 17 patients in the combined prophylaxis group experienced HBV recurrence, and HBV DNA was undetectable by PCR in at least three serum samples per patient. HBV recurrence was significantly lower when compared with the historical control group (10/43 vs. 0/17, p < 0.01). Our results suggest that combined lamivudine and HBIg can avoid the recurrence of HBV infection in patients who are HBsAg-positive/HBV DNA negative before LT.

Use of hepatitis B core antibody-positive donors in recipients without evidence of hepatitis B infection: a survey of current practice in the United States

Because of the current organ shortage, some liver transplant programs have begun to accept marginal organs that previously would have been rejected. An example is the use of donors with evidence of past hepatitis B virus (HBV) infection. To gain insight into the use of hepatitis B core antibody-positive (anti-HBc(+)) donor livers in recipients without evidence of HBV infection, we conducted a survey. Surveys consisting of 12 multiple-choice questions were sent to all 110 liver transplant programs across the United States in mid-2001, and 56 of 110 surveys (51%) could be evaluated. Overall, 32 of 56 programs (57%) indicated they would transplant an anti-HBc(+) liver into a recipient without serological evidence of HBV infection. Of those who would accept an anti-HBc(+) liver, 16 of 27 respondents (59%) indicated knowledge of HBV DNA status would change their protocol; 46% of these respondents would decrease prophylaxis if HBV DNA was negative, 27% would increase prophylaxis if HBV DNA was positive, and 27% would not accept the liver if HBV DNA was positive. Conversely, 9 of 28 respondents (32%) who would not accept an anti-HBc(+) liver stated that knowing HBV DNA status would change their protocol in that they might consider accepting livers if HBV DNA was negative. In conclusion, as of mid-2001, of transplant medical directors in the United States who responded to our survey, 57% would accept an anti-HBc(+) donor liver for an HBV-naïve recipient. Treatment protocols for using these organs varied. Knowledge about HBV DNA status of the donor and/or liver would greatly influence prophylaxis for those accepting anti-HBc(+) donor livers.

Nucleoside analogues and other antivirals for treatment of hepatitis B in the peritransplant period

Chronic HBV infection is a common cause of advanced liver disease that is associated with substantial mortality. Furthermore, chronic hepatitis B was historically a controversial indication for liver transplantation because of a low post-transplant survival, with graft infection being the major contributor to adverse outcomes. The initial use of hepatitis B immune globulin as prophylaxis, followed later by combined therapy with lamivudine, markedly reduced viral recurrence and improved the survival of patients transplanted for acute or chronic hepatitis B with liver failure. Lamivudine alone can also be used for long-term prophylaxis against de novo HBV infection that can be transmitted by organs from donors positive for anti-HBc or anti-HBs. When used in patients with decompensated chronic hepatitis B with cirrhosis, lamivudine has been shown to improve clinical manifestations, prolong pretransplant survival, and defer, or even obviate, the need for transplantation. Despite prophylaxis, viral mutations with breakthrough reinfection may occur and lead to liver failure. The recently approved adefovir dipivoxil, which is active against lamivudine-resistant mutation, and other nucleoside analogs that are in various phases of development, offer hope as rescue therapy for viral recurrence. Other therapeutic alternatives in the future may include gene therapy and immune interventions.

HBV DNA persistence 10 years after liver transplantation despite successful anti-HBS passive immunoprophylaxis

Long-term immunoprophylaxis with hepatitis B immune globulin (HBIG) is widely accepted for the prevention of recurrent hepatitis B virus (HBV) infection after liver transplantation in HBV-infected patients without viral replication. We report long-term results of HBIG administration in 284 hepatitis B surface antigen (HBsAg)-positive transplant patients. In protocol 1, 259 patients were given HBIG with the goal of maintaining the anti-HBs antibody (Ab) titer over 100 IU/L. After December 1993, 25 HBV DNA-positive patients received HBIG, with a target anti-HBs Ab titer over 500 IU/L, combined with posttransplantation antiviral therapy (protocol 2). At 10 years, 44 patients without recurrence were tested for the presence of HBV DNA in serum using real-time polymerase chain reaction (PCR); 28 were also tested in liver and peripheral blood mononuclear cells (PBMC). The overall 5- and 10-year posttransplantation actuarial rates of HBV recurrence were 24.2% and 25.4%, respectively. The 5-year recurrence rate in protocol 2 patients was 11.8%. On multivariate analysis, predictors of lower HBV recurrence risk were absence of serum HBV DNA before transplantation (P <.0001), acute liver disease (P =.0037), HDV superinfection (P =.012), and protocol 2 therapy (P <.0001). Low-level HBV DNA was detected by PCR in 45.4% of patients without HBV recurrence at 10 years. Overall actuarial 10-year survival was 74.4%. In conclusion, we confirm the efficacy of long-term HBIG immunoprophylaxis. Combination prophylaxis with HBIG and antiviral therapy is effective in patients with viral replication. Although there were only a few cases of HBV recurrence after 5 years, HBV DNA remained present in 45% of patients at 10 years.

Characterization of hepatitis B virus surface antigen and polymerase mutations in liver transplant recipients pre- and post-transplant

We evaluated serum samples from 18 chronic hepatitis B virus (HBV) patients who underwent liver transplantation for the presence of HBV polymerase and S gene mutations and HBV genotype using a new commercially available sequencing assay. All three patients with hepatitis B immune globulin (HBIG) treatment failure followed by nucleoside analogue treatment failure were infected with HBV genotype C; a pre-existing HBV S antigen (HBsAg) mutation (sD144A) was identified in one patient pretransplant, while sG145R mutations emerged in the other two patients post-transplant. These HBsAg mutations persisted for the duration of the study (5-6 years), despite the absence of HBIG administration for a 4-5-year period. Significant viral polymerase mutations (rtL180M and rtM204I/V) also emerged in all of these patients following treatment with lamivudine and/or famciclovir. Four of six patients with HBIG breakthrough without nucleoside analogue treatment failure yielded potentially significant HBsAg mutations post transplant. These data do not support previous reports highlighting the disappearance of HBsAg mutants in liver transplant recipients after discontinuation of HBIG. Determination of HBV genotype, as well as identification of HBV polymerase and S gene mutations in liver transplant candidates may be warranted to optimize HBV management strategies post transplant.

A randomized study comparing lamivudine monotherapy after a short course of hepatitis B immune globulin (HBIg) and lamivudine with long-term lamivudine plus HBIg in the prevention of hepatitis B virus recurrence after liver transplantation

BACKGROUND/AIMS

To compare the efficacy in preventing hepatitis B virus (HBV) recurrence of lamivudine vs. lamivudine plus hepatitis B immune globulin (HBIg) after a short course of HBIg and lamivudine in liver transplanted chronic hepatitis B patients.

METHODS

Forty-six patients with HBV cirrhosis received lamivudine before liver transplantation and were then randomized to receive lamivudine plus HBIg for 1 month followed by lamivudine or both drugs for 17 months.

RESULTS

Thirty-two patients were transplanted and 29 were randomized to receive combination therapy (15 cases) or lamivudine monotherapy (14 cases). HBV DNA was undetectable in all cases (17 induced by lamivudine therapy) at the time of liver transplantation. After 18 months of follow-up, all patients survived without HBV recurrence: hepatitis Bs antigen and HBV DNA were negative; however, HBV DNA was detected by polymerase chain reaction in four cases (three with HBIg plus lamivudine and one with lamivudine). Alanine aminotransferase levels were normal except in six cases (one HCV and two HDV coinfections). There were no drug-related adverse events.

CONCLUSIONS

Lamivudine monotherapy after a short course of lamivudine and HBIg is equally as efficacious in preventing HBV recurrence as HBIg plus lamivudine during the first 18 months after liver transplantation. This strategy is more economic and convenient to administer than long-term HBIg plus lamivudine.

Prevention of and treatment for hepatitis B virus infection after liver transplantation in the nucleoside analogues era

Post-transplant prophylaxis with hepatitis B immune globulin (HBIG) has significantly reduced hepatitis B virus (HBV) recurrence rates, but it is rather ineffective in patients with pretransplant viremia. Moreover, long-term HBIG administration is very expensive and may be associated with emergence of escape HBV mutants. Lamivudine has been widely used in the management of HBV transplant patients. Pretransplant lamivudine lowers HBV viremia, decreasing the risk of post-transplant HBV recurrence, but to try and minimize development of resistant HBV strains, it should start within the last 6 months of the anticipated transplantation timing. Preemptive post-transplant lamivudine monotherapy is associated with progressively increasing HBV recurrence rates, but combined therapy with lamivudine and HBIG at relatively low dosage is currently the most effective approach in this setting, even in HBV-DNA-positive patients, who also receive lamivudine in the pretransplant period. The most frequent therapy for post-transplant HBV recurrence is lamivudine, but the increasing resistance rates represent a rather challenging problem. Adefovir dipivoxil and entecavir are currently the most promising agents for lamivudine-resistant HBV strains. All these advances in anti-HBV therapy have made HBV liver disease an indication for liver transplantation irrespective of viral replication status, a complete turn around from 10 years ago.

Prophylaxis and treatment of recurrent hepatitis B after liver transplantation

Chronic hepatitis B virus (HBV) infection is the leading cause of end-stage liver disease in Asia. The results of liver transplantation in these patients have significantly improved to a level comparable to those of other recipients as a result of the rapid evolution in the strategies of prevention and treatment of recurrent hepatitis B over the past decade. Hepatitis B immune globulin (HBIG) and lamivudine, either alone or in combination, are effective in preventing reinfection, but the most cost-effective dosing regimen with optimum efficacy without the prohibitive cost remains to be determined, an issue that is particularly relevant to liver transplant centers with serious financial constraints in Asia. The idea of active immunization is attractive, but the results have been conflicting to date. The newer nucleoside analogs appear most promising, and a combination of two or more antiviral agents is likely to represent the future strategy of choice in the prophylaxis and treatment of recurrent hepatitis B after liver transplantation.

Conversion from intravenous to intramuscular hepatitis B immune globulin in combination with lamivudine is safe and cost-effective in patients receiving long-term prophylaxis to prevent hepatitis B recurrence after liver transplantation

Recurrent hepatitis B infection after liver transplantation was previously frequent and associated with significant allograft failure and mortality. Recurrence rates of hepatitis B were improved with the use of passive immunoprophylaxis with hepatitis B immune globulin, and later, lamivudine monotherapy. Combination prophylaxis with intravenous hepatitis B immune globulin and lamivudine substantially decreased rates of hepatitis B recurrence, but intravenous administration of hepatitis B immune globulin was expensive and associated with significant adverse effects. In the current study, 59 patients receiving primary liver transplantation for chronic hepatitis B infection were prospectively followed up after converting from intravenous to intramuscular hepatitis B immune globulin in combination with lamivudine. All patients tolerated intramuscular hepatitis B immune globulin well. At a median follow-up of 511 days after conversion to intramuscular hepatitis B immune globulin, 58 of 59 patients (98.3%) were hepatitis B surface antigen-negative. Twenty-one patients (35.6%) required a median of one supplemental intravenous hepatitis B immune globulin infusion to maintain therapeutic antibody levels. Economic analysis showed an average cost-effectiveness ratio for combination intramuscular hepatitis B immune globulin plus lamivudine of $52,600 per recurrence prevented, which was far below the cost of lamivudine monotherapy and of intravenous hepatitis B immune globulin alone or in combination with lamivudine. These results suggest that intramuscular administration of hepatitis B immune globulin in combination with lamivudine offers a safe, effective, and cost-effective approach to preventing hepatitis B recurrence after orthotopic liver transplantation.

Adoptive transfer of donor-derived immunity by liver transplantation: a potential avenue to prevent hepatitis B virus reinfection

Immunity to hepatitis B has been successfully transferred by bone marrow transplantation, but has also occurred after liver transplantation (LTx). This study was designed to analyse the influence of alloreactivity and immunosuppression, on the efficacy of adoptive immune transfer to hepatitis B by liver transplantation. Orthotopic LTx (n = 34) were performed in three rat strain combinations representing different genetic constellations. Donors had been vaccinated twice with recombinant hepatitis B surface antigen while recipients were unimmunized. Half of the allogeneic recipients were immunosuppressed with cyclosporin A. All animals were monitored weekly for the presence of anti-hepatitis B surface antibodies (anti-HBs). Effective anti-HBs titres were detected in 85% (29/34) of liver recipients and lasted from 2 to 10 weeks. Donor titre above >15 000 mIU/mL ensured a 100% seroconversion rate in the recipients. The maximal anti-HBs titre in recipients represented 0.06% approximately 0.76% of the donor titre. Rejection reduced the adoptive immune transfer, which was protected by immunosuppression. These observations suggest that transfer of functionally active donor lymphocytes, deriving from the graft, contributed to the donor-derived immune response in the recipient. Further studies to augment the donor-derived immune response are warranted to ensure a therapeutic effect for the recipient at risk of reinfection.

Expected developments in hepatology

It is very difficult to predict new developments in hepatology so we have decided to analyse the most important issues related to three clinical conditions in hepatology. The first is chronic hepatitis. Here, we discuss the relevance of occult forms of hepatitis B virus infection in the development of cryptogenic liver disease and hepatocellular carcinoma. In addition, the role of genotyping in hepatitis B is analysed, indicating that patients with genotype A have a better prognosis than those with genotype D. The treatment of hepatitis B virus infection is also reviewed, and it has been suggested that research should be directed towards the development of new anti-viral agents to suppress virus replication. The natural history of hepatitis C virus infection is considered, emphasizing the need to know the progression of fibrosis in these patients. The chapter also suggests that treatment of hepatitis C virus infection with pegilated interferon and ribavirin is currently relatively effective. New therapeutic strategies will be required in the future, the most important challenge being the development of a hepatitis C virus vaccine. The second section is on chronic cholestasis. The role of anti-mitochondrial antibodies in primary biliary cirrhosis is considered. The possible infectious agents implicated as potential triggers of primary biliary cirrhosis are also discussed, suggesting that several infections may play a role in the pathogenesis of this condition. Other aetiopathogenic factors, for example organic compounds, drugs and chemicals, are indicated. It is possible that, in the near future, the precise sequence and molecular basis by which infectious agents or xenobiotics may initiate the cascade of the autoimmune response will be defined. One of the most important challenges in primary sclerosing cholangitis concerns the mechanisms that may induce the development of this disease. Up until now, genetic factors have been suggested, recent data reporting a clear-cut association between primary sclerosing cholangitis and the tumour necrosis factor-alpha(2) allele. The third part of this chapter includes recent progress achieved in hepatocellular carcinoma, discussing developments in the knowledge of hepatocellular carcinogenesis. Hepatocellular carcinomas appear so far to be genetically heterogeneous neoplasms, and this heterogeneity may correlate with the variety of aetiological factors involved. The risk factors and primary, secondary and tertiary prevention of the condition are also analysed. Finally, the development of new therapeutic strategies for hepatocellular carcinoma is evaluated by evidence-based studies.

Hepatitis B: progress in the last 15 years

1. Patients undergoing orthotopic liver transplantation (OLT) for hepatitis B without effective prophylaxis have a high risk for recurrent infection and severe graft damage, leading to death or re-OLT. 2. Long-term prophylaxis with hepatitis B immune globulin (HBIg) significantly reduces the risk for hepatitis B virus (HBV) recurrence and increases survival. Patients with detectable HBV DNA at the time of OLT have a high risk for recurrence despite HBIg prophylaxis. 3. Lamivudine (LAM) therapy for patients with decompensated HBV cirrhosis before OLT results in inhibition of viral replication and clinical improvement. Its efficacy is limited by the frequent emergence of LAM-resistant YMDD mutations. The ideal length of therapy with LAM pre-OLT has not yet been defined. 4. Prophylaxis of HBV recurrence with LAM monotherapy is not recommended because of the reappearance of hepatitis B surface antigen after OLT in approximately 50% of patients. 5. LAM is the best available treatment for patients with established recurrent hepatitis B. Long-term therapy is associated with the emergence of drug-resistant mutants in up to 60% of patients. Severe hepatitis and liver failure have been described among liver transplant recipients with YMDD mutations. 6. Combination therapy with HBIg and LAM prevents HBV recurrence in 90% to 100% of patients who undergo OLT for hepatitis B. The optimal HBIg protocol in the LAM era is yet to be defined. 7. Preliminary studies suggest that adefovir dipivoxil inhibits HBV replication in patients infected with LAM-resistant HBV strains. 8. Fifteen years ago, hepatitis B was regarded as a relative or absolute contraindication for OLT. Today, hepatitis B is a universally accepted indication for OLT.

Successful hepatitis B vaccination in patients who underwent transplantation for hepatitis B virus-related cirrhosis: preliminary results

Long-term hepatitis B immunoglobulin (HBIg) prophylaxis prevents endogenous hepatitis B virus (HBV) reinfection in the majority of liver transplant recipients. Active hepatitis B vaccination after orthotopic liver transplantation (OLT) in these patients has produced conflicting results to date. On this study, patients who remained hepatitis B surface antigen (HBsAg) negative with passive immunization after OLT for HBV cirrhosis were actively immunized using recombinant HBV antigen (Engerix), together with a novel adjuvant system (monophosphoryl lipid A and a natural saponine molecule). This led to a sustained antibody response to HBsAg (>500 IU/L) in 5 of 10 patients. This antibody response prevented reinfection and allowed termination of prophylactic HBIg substitution for more than 12 months in these patients.

Clinical evaluation (phase I) of a combination of two human monoclonal antibodies to HBV: safety and antiviral properties

Treatment of chronic hepatitis B virus (HBV) infection with interferon alfa and lamivudine is characterized by lack of viral clearance, loss of response, or emergence of drug-resistant mutants. Thus, new and multiple drug approaches are needed. We have developed two fully human monoclonal antibodies, directed against different epitopes of hepatitis B surface antigen (HBsAg) that bind to all major HBV subtypes. A phase I clinical study was conducted to evaluate the safety, tolerability, and efficacy of a mixture of these two monoclonal antibodies, HBV-AB(XTL). A total of 27 chronic HBV patients were enrolled. In part A of the study 15 patients in 5 cohorts received a single intravenous infusion of antibodies with doses ranging from 0.26 mg (260 IU) to 40 mg (40,000 IU). All patients completed 16 weeks of follow-up. In the second part of the study (part B), 12 patients in 4 cohorts received 4 weekly infusions of 10, 20, 40, or 80 mg each of HBV-AB(XTL) and were followed for 4 additional weeks. Administration of antibodies was well tolerated. Patients administered doses at an Ab:Ag molar ratio of 1:2 to 1:20 showed a rapid and significant decrease in HBsAg to undetectable levels, with a corresponding reduction of HBV-DNA levels. In part B, HBV-AB(XTL) induced a significant reduction in both HBsAg and HBV-DNA levels repeatedly after administration. In conclusion, these data suggest that HBV-AB(XTL) binds HBV particles and reduces serum viral titers and HBsAg levels. HBV-AB(XTL) could be combined with other monotherapies that are currently used to treat HBV carriers.

A concise update on the status of liver transplantation for hepatitis B virus: the challenges in 2002

Significant improvements in both patient and graft survival after orthotopic liver transplantation (OLT) for hepatitis B virus (HBV)-related liver failure have been made during the last decade. Recurrence of HBV infection has decreased, even in high-risk patients. Despite ongoing progress, challenges remain for the next millennium, including the determination of cost-effective dosing strategies, treatment of HBV infection in liver transplant recipients, and ramifications of the use of new antiviral agents, specifically, the appearance of resistant strains. This review summarizes the relevant history of OLT for chronic viral hepatitis B, details accepted preventive and therapeutic treatments, and discusses ongoing experimental trials. Emphasis also is placed on new approaches in transplantation as they impact on the care of HBV-infected patients.

Failure of a reinforced triple course of hepatitis B vaccination in patients transplanted for HBV-related cirrhosis

Long-term immunoprophylaxis with anti-HBs immunoglobulins (HBIg) is used to prevent hepatitis B (HBV) reinfection after liver transplantation for HBV-related cirrhosis. This approach is highly expensive. A recent report proposed posttransplant HBV vaccination with a reinforced schedule as an alternative strategy to allow HBIg discontinuation. We investigated the efficacy of a reinforced triple course of HBV vaccination in 17 patients transplanted for HBsAg-positive cirrhosis 2 to 7 years earlier. The first cycle consisted of 3 double intramuscular doses (40 microg) of recombinant vaccine at month 0, 1, and 2, respectively. This was followed, in nonresponders, by a second cycle of 6 intradermal 10 microg doses every 15 days. All nonresponders then received a third cycle identical to the first one. Vaccination started 4.5 months after HBIg discontinuation, and lamivudine (100 mg/day) was given throughout the study. All patients were seronegative for HBsAg and HBV-DNA (by PCR) and positive for anti-HBe, and 7 were positive for anti-HDV. After the first cycle one patient (#5, 53 years old, male) developed an anti-HBs titer of 154 IU/L, another (#12) reached a titer of 20 IU/L and the remainder had titers <10 IU/L. At month 7, patient #5 reached a titer of 687 IU/L. After the second cycle only one additional patient (#9) had a slight response (an anti-HBs titer of 37 IU/L). After the third cycle patient #9 rose to an anti-HBs titer of 280 IU/L, patient #12 dropped to 10 IU/L, and no other patient responded. In conclusion, a highly reinforced HBV vaccination program is effective only in a few patients who had liver transplants for HBV-related cirrhosis.

Posttransplantation care: role of the primary care physician versus transplant center

1. Forty percent of transplant centers expect the primary care physician to be the primary physician; 40% have both a primary care physician and a hepatologist manage the patient. 2. Transplant centers expect primary care physicians to provide general preventive medicine, physical examinations, vaccinations, and, rarely, management of hypertension, renal dysfunction, and diabetes. 3. A high percentage of primary care physicians feel comfortable caring and managing the overall health care of a long-term liver transplant patient. 4. Primary care physicians feel at most ease managing preventive care, annual physical examinations, hypertension, diabetes mellitus, hyperlipidemia, bone disease, and vaccinations. 5. Primary care physicians should be aware of the common medical conditions of the liver transplant patient of hypertension, diabetes, obesity, hyperlipidemia, and recurrent disease. 6. Common medical conditions for both the transplant centers and primary care physicians are hypertension, dyslipidemia, diabetes mellitus, malignancy, bone disease, pregnancy, vaccination, infectious prophylaxis, and headaches.

Hepatitis B and C in the liver transplant recipient: current understanding and treatment

1. Liver disease related to chronic viral hepatitis is the leading indication for orthotopic liver transplantation (OLT) worldwide. 2. The natural history of hepatitis B virus infection has been dramatically modified, and outcome has improved substantially in the last decade with the use of hepatitis B immunoglobulin and lamivudine. 3. Hepatitis C virus (HCV) recurrence, defined by histological injury, is almost universal, and a subset of patients (20% to 30%) develops allograft cirrhosis by the fifth year post-OLT. 4. Unfortunately, antiviral therapy for hepatitis C post-OLT, even when initiated preemptively before the development of histological recurrence in the first few weeks post-OLT, has failed to alter the natural history of HCV disease recurrence. 5. HCV-related allograft cirrhosis is associated with a high rate of decompensation and mortality.

Late hepatic allograft dysfunction

1. Lifelong monitoring of graft function, immunosuppressive levels, and screening for drug toxicity is required in all liver recipients. 2. Late hepatic allograft dysfunction is common and is caused by a variety of etiologies including rejection, infection, biliary/vascular abnormalities, recurrence of disease, and drug hepatotoxicity. 3. In all patients with late hepatic allograft dysfunction, liver biopsy should be performed to assess for the presence of rejection, and to thus avoid excessive use of bolus corticosteroid therapy and guide appropriate immunosuppressive management. 4. Recurrence of disease is the most common cause of late hepatic allograft dysfunction. 5. Hepatitis C universally reinfects the hepatic allograft, and is associated with decreased patient and graft survival and leads to the recurrence of cirrhosis in 28% of patients within 5 years of transplantation. 6. Major advances have been made in preventing recurrence of hepatitis B by the use of hepatitis B immune globulin in combination with lamivudine therapy. 7. Autoimmune liver diseases such as primary biliary cirrhosis, primary sclerosing cholangitis, and autoimmune hepatitis have a recurrence rate of approximately 20% to 30%. 8. In patients developing recurrence of autoimmune hepatitis, steroid withdrawal is the most common cause. 9. Recurrent hepatocellular cancer can be markedly reduced if strict guidelines are adhered to in selecting patients. 10. Drug hepatotoxicity must always be considered in the differential diagnosis of late hepatic allograft dysfunction.