Comparison of famciclovir and lamivudine in the long-term treatment of hepatitis B infection after liver transplantation

Current therapeutic strategies for recurrent hepatitis B virus infection after liver transplantation

Hepatitis B virus (HBV)-related liver disease is the leading indication for liver transplantation (LT) in Asia, especially in China. With the introduction of hepatitis B immunoglobulin (HBIG) and oral antiviral drugs, the recurrent HBV infection rate after LT has been evidently reduced. However, complete eradication of recurrent HBV infection after LT is almost impossible. Recurrent graft infection may lead to rapid disease progression and is a frequent cause of death within the first year after LT. At present, the availability of new oral medications, especially nucleoside or nucleotide analogues such as adefovir dipivoxil, entecavir and tenofovir disoproxil fumarate, further strengthens our ability to treat recurrent HBV infection after LT. Moreover, since combined treatment with HBIG and antiviral agents after liver re-transplantation may play an important role in improving the prognosis of recurrent HBV infection, irreversible graft dysfunction secondary to recurrent HBV infection in spite of oral medications should no longer be considered an absolute contraindication for liver re-transplantation. Published reviews focusing on the therapeutic strategies for recurrent HBV infection after LT are very limited. In this article, the current therapeutic strategies for recurrent HBV infection after LT and evolving new trends are reviewed to guide clinical doctors to choose an optimal treatment plan in different clinical settings.

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

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

Favorable outcome of de novo hepatitis B infection after liver transplantation with lamivudine and adefovir therapy

De novo hepatitis B virus (HBV) infection after orthotopic liver transplantation (OLT) always progresses to chronic hepatitis because of the patients' immunocompromised status, and only a few then acquire hepatitis B surface antigen (HBsAg) seroconversion even with efficient antiviral therapy. Here we reported the case of a liver transplant recipient with de novo HBV infection who had a favorable outcome after lamivudine (LAM) and adefovir dipivoxil (ADV) antiviral therapy. The patient received OLT because of end-stage primary biliary cirrhosis and was found to have de novo HBV infection 3 months later. She was treated with LAM, and her serum HBV DNA turned undetectable 2 weeks later. However, serum HBV DNA turned detectable again after 9 months of LAM therapy and a YMDD mutation was detected. The addition of ADV was efficient to treat LAM-resistant HBV. After 3 months of combination therapy, LAM was stopped and ADV monotherapy was continued. HBsAg seroconversion was achieved after an additional 12 months. The prevention and treatment of de novo HBV infection after OLT is discussed.

[Liver transplantation for chronic hepatitis B]

Liver transplantation for hepatitis B represents 5-10 % of all liver transplantations performed in Europe. The prognosis after liver transplantation is related to the efficacy of prophylaxis of HBV graft reinfection. The risk of HBV reinfection is directly related to the HBV viral load at transplantation. HBV prophylaxis after transplantation with long-term administration of anti-HBS immune globulins (HBIG) or with monoprophylaxis with lamivudine can reduce significantly the risk of HBV recurrence mainly in patients without active HBV replication. Antivirals such as lamivudine, adefovir, entecavir or tenofovir can control HBV replication in patients with decompensated HBV cirrhosis waiting for transplantation. However, there is a risk of HBV viral breakthrough during nucleo (t) side antiviral treatment. The use of an antiviral alone or in combination should take into account the antiviral efficacy and the risk of viral resistance. The post-transplant combination of antiviral therapy and HBIG prophylaxis is very effective in reducing the rate of HBV reinfection to less than 10 % even in patients with HBV replication at transplantation. In the absence of active viral replication at transplantation, the possibilty to discontinue HBIG prophylaxis at long-term after transplantation with maintenance of antiviral treatment or HBV vaccination is in evaluation. The use of new antiviral therapies (nucleos(t)ide analogues) has dramatically improved the prognosis of patients with HBV reinfection of the graft. The current 5-year survival after liver transplantation for HBV related liver disease is 85 %. In conclusion, the prophylaxis of HBV reinfection combining antiviral therapy prior to transplantation, and combination of HBIG and antiviral therapy post-transplantation is effective in reducing the rate of HBV reinfection to less than 10 %.

Pharmacology, clinical efficacy and safety of lamivudine in hepatitis B virus infection

Lamivudine was the first nucleoside analog for the treatment of chronic hepatitis B (CHB). It is well-tolerated and induces a decrease in serum HBV DNA levels associated with normalization of serum alanine aminotransferase levels. However, a sustained response with hepatitis B 'e' antigen to anti-hepatitis B e seroconversion is obtained in a smaller proportion of patients and hepatitis B surface antigen loss is exceptional. The response is maintained during therapy, and needs to be continued indefinitely in the majority of patients since withdrawal of treatment is generally followed by a rapid reappearance of the virus. However, mutations can be induced in long-term treatment.

Liver transplantation()

Orthotopic liver transplantation (OLT) involves the substitution of a diseased native liver with a normal liver (or part of one) taken from a deceased or living donor. Considered an experimental procedure through the 1980s, OLT is now regarded as the treatment of choice for a number of otherwise irreversible forms of acute and chronic liver disease.The first human liver transplantation was performed in the United States in 1963 by Prof. T.E. Starzl of the University of Colorado. The first OLT to be performed in Italy was done in 1982 by Prof. R. Cortesini. The procedure was successfully performed at the Policlinico Umberto I of the University of Rome (La Sapienza).The paper reports the indications for liver transplantation, donor selection and organ allocation in our experience, surgical technique, immunosuppression, complications and results of liver transplantation in our center.

Prevention and treatment of recurrent Hepatitis B after liver transplantation: the current role of nucleoside and nucleotide analogues

The Hepatitis B virus (HBV) is a DNA virus that can cause both acute and chronic liver disease in humans. Approximately 350–400 million people are affected worldwide and up to one million deaths occur annually from cirrhosis and hepatocellular carcinoma. When cirrhosis and liver failure develop, the definitive treatment of choice remains orthotopic liver transplantation (OLT). In the past, an unacceptable HBV recurrence rate with a high rate of graft loss was noted. The use of Hepatitis B immunoglobulin (HBIG) has resulted in improved patient and graft survival rates. The addition of the nucleoside analog Lamivudine (LAM) to HBIG has improved these survival curves to an even greater degree. Prolonged use of LAM will almost invariably lead to the development of viral mutations resistant to the drug. There are now several other nucleoside and nucleotide analogs (Adefovir, Entecavir, Tenofovir, and Truvada) available for the clinician to utilize against these resistant strains. It should be possible to prevent recurrence in most, if not all, post-transplant patients and also to significantly reduce viral loads with normalization of transaminases in those who have developed recurrent infection. The antiviral regimen should be robust and minimize the risk of breakthrough mutations. A prudent approach may be the implication of combination antiviral therapy. This review summarizes the efficacy of previous regimens utilized to prevent and treat recurrent HBV following OLT. Particular attention will be paid to the newer nucleoside and nucleotide analogs and the direction for future strategies to treat HBV in the post transplant setting.

[Liver transplantation for complications of hepatitis B]

In the absence of prophylaxis, there is an elevated risk of virus recurrence after liver transplantation required because of chronic hepatitis B. Regardless of prophylaxis, the risk of recurrence is associated with pre-graft viral load. Long-term prophylaxis by hepatitis B immune globulin (HBIG) significantly reduces the risk of recurrence, especially if there was no pre-graft viral replication. Use of antiviral agents such as lamivudine, adefovir, tenofovir, and entecavir, control HBV replication in patients with decompensation of cirrhosis while awaiting transplantation and in patients with HBV recurrence post-graft. The risk of emergence of resistant strains limits the use of these antiviral agents. The choice of one or several combined antiviral agents depends on their resistance profiles. Combining antiviral agents and HBIG after transplantation can reduce the risk of HBV recurrence to less than 10%, even in patients with viral replication pre-graft. If there was no detectable viral load pre-graft, withdrawal of HBIG should be considered at some point, while continuing an antiviral agent or after anti-HBV vaccination.

Study on the Efficacy and Safety of Adefovir Dipivoxil Treatment in Post–Liver Transplant Patients With Hepatitis B Virus Infection and Lamivudine-Resistant Hepatitis B Virus

Hepatitis B virus (HBV) recurrence and de novo HBV infection are frequent events in liver transplantation recipients. Treatment with lamivudine is initially efficient in both infections but the incidence of lamivudine-resistant HBV emergence increases over time. Adefovir appears to be promising in post-liver transplantation patients with recurrent HBV infection and lamivudine-resistant HBV. This study analyzed adefovir treatment in 42 post-liver transplantation patients who developed recurrent HBV or de novo HBV infection with lamivudine-resistant HBV (54.8% HCV-coinfected). Patients received 10 mg of oral adefovir once daily for a mean period of time of 21.5 months (range from 12 to 31 months). In 62.9% of patients, ALT levels decreased significantly. Serum HBV-DNA was undetectable in 64% of the cases. Twenty percent of patients lost HBeAg marker and 13.3% of them developed anti-HBe. In 9.5% of recipients, HBsAg became negative. There was no significant change in serum creatinine levels. In only one patient was worsening of the renal function detected, making dose adjustment necessary. No other side effects were reported. Our results confirm the efficacy and safety of adefovir treatment in post-liver transplantation patients with lamivudine-resistant HBV, neither were adefovir-resistant mutations identified in patients after 21 months of therapy, nor were there adverse events, especially renal toxicity.

Viral prophylaxis in organ transplant patients

Viral pathogens have emerged as the most important microbial agents having deleterious effects on solid organ transplant (SOT) recipients. Antiviral chemoprophylaxis involves the administration of medications to abort transmission of, avoid reactivation of, or prevent progression to disease from, active viral infection. Cytomegalovirus (CMV) is the major microbial pathogen having a negative effect on SOT recipients. CMV causes infectious disease syndromes, augments iatrogenic immunosuppression and is commonly associated with opportunistic superinfection. CMV has also been implicated in the pathogenesis of rejection. Chemoprophylactic regimens for CMV have included oral aciclovir (acyclovir) at medium and high doses, intravenous and oral ganciclovir, and the prodrugs valaciclovir (valacyclovir) and valganciclovir. CMV prophylactic strategies should be stratified, with the highest-risk patients receiving the most 'potent' prophylactic regimens. Herpes simplex virus (HSV) reactivation in SOT recipients is more frequent, may become more invasive, takes longer to heal, and has greater potential for dissemination to visceral organs than it does in the immunocompetent host. Prophylactic regimens for CMV are also effective chemoprophylaxis against HSV; in the absence of CMV prophylaxis, aciclovir, valaciclovir or famciclovir should be used as HSV prophylaxis in seropositive recipients. Primary varicella-zoster virus (VZV) after SOT is rare and most commonly seen in the paediatric transplant population because of VZV epidemiology. Zoster occurs in 5-15% of patients, usually after the sixth post-transplant month. Prophylactic regimens for zoster are neither practical nor cost effective after SOT because of the late onset of disease and low proportion of affected individuals. All SOT recipients should receive VZV immune globulin after contact with either varicella or zoster. Epstein-Barr virus has its most significant effect in SOT as the precipitating factor in the development of post-transplant lymphoproliferative disorders. Antiviral agents that could be effective are the same as those used for CMV, but indications for and effectiveness of prophylaxis are poorly established. Hepatitis B virus (HBV) and hepatitis C virus (HCV) are important pathogens in the SOT population as indications for transplantation. So-called 'prophylaxis' for recurrent HBV and HCV after liver transplantation is controversial, suppressive rather than preventive, and potentially lifelong. Influenza infection after SOT is acquired by person-to-person contact. During epidemic periods of influenza, transplant populations experience a relatively high frequency of infection, and influenza may affect immunosuppressed SOT recipients more adversely than immunocompetent individuals. Antiviral medications for prevention of influenza are administered as post-exposure prophylaxis to SOT recipients, in addition to yearly vaccine, in circumstances such as influenza epidemics and nosocomial outbreaks, and after exposure to a symptomatic individual during 'flu season'.

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.

Liver transplantation for HBV and management of reinfection

Follicular non-Hodgkin's lymphoma (NHL) represents the most common indolent lymphoma with a median survival of 10 years. A new prognostic index (FLIPI) provides prognostic information at diagnosis and at relapse. Initial treatments combining monoclonal antibody therapy using rituximab with chemotherapy appear to increase the response rate and decrease the risk of relapse with little increase in toxicity. Promising phase III trial results demonstrating improvements in outcome using rituximab have recently been reported. A number of phase II trials have also demonstrated encouraging activity combining radiolabeled antibodies in sequence with chemotherapy. The role of high-dose therapy and autologous transplantation is becoming more defined, with improvements in progression-free survival observed in the upfront and relapsed setting. The application of allogeneic transplantation, once restricted to young otherwise healthy patients has shown encouraging activity in older, relapsed, and refractory patients using nonmyeloablative conditioning regimens. These new treatment options make the management of newly diagnosed patients both exciting and a challenge.

Liver transplant and recurrent disease

Current prophylactic measures have greatly reduced recurrence rates of hepatitis B after liver transplantation. HBIG remains a critically important compound and although there is variability in dosing regimens and target anti-HBs levels, it is the backbone of recurrence prevention. Adjuvant therapies with nucleoside/nucleotide analogs alone have been limited by drug-resistant strains of HBV, but the armamentarium of these molecules continues to grow and hence the management of the post-LT HBV patient will evolve further. Currently lamivudine with HBIG remains an excellent option provided the patient has not developed resistance, especially in the pre-LT period. Adefovir is the drug of choice in that setting and perhaps the preferred drug in the pre-LT setting to allow the use of lamivudine post-LT. Further testing with tenofovir and newer compounds in development will expand these options. The use of multiple nucleoside analogs is an intriguing option, based on the HIV experience of reducing drug resistance and optimizing viral suppression, and will likely be further studied.

Adefovir dipivoxil therapy for lamivudine-resistant hepatitis B in pre- and post-liver transplantation patients

Three-hundred and twenty-four patients were enrolled in an open-label, multicenter, international study in which pre- and post-liver transplantation (LT) patients with recurrent chronic hepatitis B (CHB) and evidence of lamivudine-resistant HBV were treated with adefovir dipivoxil 10 mg once daily. In the pre- and post-LT cohorts, 128 and 196 patients were treated for a median duration of 18.7 and 56.1 weeks, respectively. In patients who received 48 weeks of treatment, 81% of the pre-LT and 34% of the post-LT cohort achieved undetectable serum hepatitis B virus (HBV) DNA (Roche Amplicor Monitor polymerase chain reaction [PCR] assay lower limit of quantification [LLQ] < 400 copies/mL) with a median change in serum HBV DNA from baseline of -4.1 log(10) and -4.3 log(10) copies/mL, respectively. Serum alanine aminotransferase (ALT), albumin, bilirubin, and prothrombin time normalized in 76%, 81%, 50%, and 83% of pre-LT patients and 49%, 76%, 75%, and 20% of post-LT patients. The Child-Pugh-Turcotte (CPT) score improved in over 90% of patients in both cohorts. Genotypic analysis of 122 HBV baseline samples revealed that 98% of these patients had lamivudine-resistant mutant HBV. No adefovir resistance mutations were identified in patients after 48 weeks of therapy. One-year survival was 84% for pre-LT and 93% for post-LT patients (Kaplan-Meier analysis). Treatment-related adverse effects associated with adefovir dipivoxil in this setting were primarily mild to moderate in severity. In conclusion, 48 weeks of adefovir dipivoxil resulted in significant improvements in virologic, biochemical, and clinical parameters in CHB patients pre- and post-LT with lamivudine-resistant HBV.

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.

Treatment of recurrent hepatitis B infection in liver transplant recipients

1. Therapeutic decisions are guided by a patient's clinical status (severity of disease and presence of comorbidities) and previous drug-exposure history. 2. Lamivudine is safe and effective in liver transplant recipients with recurrent hepatitis B virus (HBV) infection caused by wild-type virus or failure of hepatitis B immunoglobulin therapy. Lamivudine resistance, developing in approximately 25% after 12 months of therapy, is its main limitation. 3. Famciclovir is safe in liver transplant recipients; however, virological and clinical responses are less consistent than with lamivudine. Thus, lamivudine is favored over famciclovir as first-line therapy in transplant recipients with no previous exposure to nucleoside analogues. 4. Although limited in availability, adefovir dipivoxil appears safe and effective in treating liver transplant recipients with lamivudine-resistant HBV disease. Close monitoring of renal function is recommended, with dose adjustment in patients with reduced creatinine clearances. 5. Limited data suggest that intravenous ganciclovir, tenofovir disoproxil fumarate, and interferon alfa may be useful as rescue therapies for patients with lamivudine- or famciclovir-resistant HBV disease. 6. Antiviral therapy with two or more suitable agents may minimize the chance for viral resistance; therefore, future therapeutic strategies likely will use combination therapy in the long-term management of recurrent HBV disease.

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.

Famciclovir treatment of chronic delta hepatitis

BACKGROUND/AIMS

Interferon is the only established therapy for chronic delta hepatitis and alternative treatment options are an urgent need. Since successful treatment of a case of post-transplant delta hepatitis with the nucleoside analogue famciclovir had been reported, a pilot study was undertaken to evaluate the use of famciclovir in the treatment of chronic delta hepatitis.

METHODS

A total of 15 adult patients, 13 men, two women, ages 20-52 years, with chronic delta hepatitis were treated with famciclovir, 500 mg, three times a day for 6 months and were then followed-up for 6 months posttreatment. All patients had compensated chronic liver disease, elevated liver enzymes and were hepatitis delta virus (HDV) RNA positive by polymerase chain reaction at baseline. Patients were monitored and tested for HBsAg, hepatitis B virus (HBV) DNA and HDV RNA levels. Liver biopsies were obtained before starting famciclovir and within 1 month of completion of treatment.

RESULTS

HBV DNA levels decreased in nine of the 15 patients and levels rose again after treatment (P<0.05). Famciclovir had no effect on alanine aminotransferase (ALT) and HBsAg levels or on serum HDV RNA and overall, there was no improvement in liver histology.

CONCLUSIONS

Treatment of chronic delta hepatitis with famciclovir has no effect on disease activity and HDV RNA levels.

Immunisations in solid-organ transplant recipients

Solid-organ transplant recipients are at increased risk of various infectious diseases, some of which are vaccine preventable mmunisations are among the most efficient interventions available. Solid-organ tranplant recipients would greatly benefit from effective immunisations, provided the recommendations are based on a careful risk-benefit analysis in which the effectiveness of the vaccine is weighed against possible adverse reactions, including graft rejection. In this review, we summarise the data from studies on relevant immunisations in solid-organ transplant recipients. The major issues are the immunogenicity and safety of immunisations, the factors associated with poor immune response, and recommendations for immunisation schemes.