Treatment of recurrent hepatitis B infection in liver transplant recipients

Chronic hepatitis B in children and adolescents: epidemiology and management

Hepatitis B virus (HBV) infection is a worldwide health problem, which can cause acute liver failure, acute hepatitis, chronic hepatitis, liver cirrhosis, and liver cancer. It is most prevalent in Asia, Africa, Southern Europe, and Latin America. Approximately 2 billion people in the world have been infected by HBV, with more than 350 million as chronic carriers. Implementation of the HBV vaccine led to a significant reduction in viral transmission in many areas of the world; however, it remains highly endemic in many developing countries. The main source of infection in childhood is via perinatal transmission or horizontal transmission during preschool years. The majority of children with chronic hepatitis B (CHB) infection are asymptomatic; however, they may develop progressive disease and are at increased risk of advanced liver disease or liver cancer before their third decade. All children with chronic HBV infection should be regularly monitored for disease progression. The goal of therapy for children with CHB is to arrest disease progression and reduce the risk of developing cirrhosis and cancer. The available medications have a low success rate because of immunotolerance in the child and the development of viral resistance to standard therapy. Therefore, case selection and determination of the best time to commence treatment are essential to increase treatment efficacy and reduce the risk of viral resistance.

Virologic and clinical outcomes of hepatitis B virus infection in HIV-HBV coinfected transplant recipients

Liver transplantation (LT) is the treatment of choice for end-stage liver disease, but is controversial in patients with human immunodeficiency virus (HIV) infection. Using a prospective cohort of HIV-hepatitis B virus (HBV) coinfected patients transplanted between 2001-2007; outcomes including survival and HBV clinical recurrence were determined. Twenty-two coinfected patients underwent LT; 45% had detectable HBV DNA pre-LT and 72% were receiving anti-HBV drugs with efficacy against lamivudine-resistant HBV. Post-LT, all patients received hepatitis B immune globulin (HBIG) plus nucleos(t)ide analogues and remained HBsAg negative without clinical evidence of HBV recurrence, with a median follow-up 3.5 years. Low-level HBV viremia (median 108 IU/mL, range 9-789) was intermittently detected in 7/13 but not associated with HBsAg detection or ALT elevation. Compared with 20 HBV monoinfected patients on similar HBV prophylaxis and median follow-up of 4.0 years, patient and graft survival were similar: 100% versus 85% in HBV mono- versus coinfected patients (p = 0.08, log rank test). LT is effective for HIV-HBV coinfected patients with complications of cirrhosis, including those who are HBV DNA positive at the time of LT. Combination HBIG and antivirals is effective as prophylaxis with no clinical evidence of HBV recurrence but low-level HBV DNA is detectable in approximately 50% of recipients.

Antiviral effects of lamivudine, emtricitabine, adefovir dipivoxil, and tenofovir disoproxil fumarate administered orally alone and in combination to woodchucks with chronic woodchuck hepatitis virus infection

Adefovir dipivoxil (ADV) and tenofovir disoproxil fumarate (TDF) are nucleotide analogs that inhibit the replication of wild-type hepatitis B virus (HBV) and lamivudine (3TC)-resistant virus in HBV-infected patients, including those who are coinfected with human immunodeficiency virus. The combination of ADV or TDF with other nucleoside analogs is a proposed strategy for managing antiviral drug resistance during the treatment of chronic HBV infection. The antiviral effect of oral ADV or TDF, alone or in combination with 3TC or emtricitabine (FTC), against chronic woodchuck hepatitis virus (WHV) infection was evaluated in a placebo-controlled study in the woodchuck, an established and predictive model for antiviral therapy. Once-daily treatment for 48 weeks with ADV plus 3TC or TDF plus FTC significantly reduced serum WHV viremia levels from the pretreatment level by 6.2 log(10) and 6.1 log(10) genome equivalents/ml serum, respectively, followed by TDF plus 3TC (5.6 log(10) genome equivalents/ml), ADV alone (4.8 log(10) genome equivalents/ml), ADV plus FTC (one survivor) (4.4 log(10) genome equivalents/ml), TDF alone (2.9 log(10) genome equivalents/ml), 3TC alone (2.7 log(10) genome equivalents/ml), and FTC alone (2.0 log(10) genome equivalents/ml). Individual woodchucks across all treatment groups also demonstrated pronounced declines in serum WHV surface antigen, characteristically accompanied by declines in hepatic WHV replication and the hepatic expression of WHV antigens. Most woodchucks had prompt recrudescence of WHV replication after drug withdrawal, but individual woodchucks across treatment groups had sustained effects. No signs of toxicity were observed for any of the drugs or drug combinations administered. In conclusion, the oral administration of 3TC, FTC, ADV, and TDF alone and in combination was safe and effective in the woodchuck model of HBV infection.

Adefovir dipivoxil therapy in liver transplant recipients for recurrence of hepatitis B virus infection despite lamivudine plus hepatitis B immunoglobulin prophylaxis

BACKGROUND

Treatment of post-transplantation recurrence of hepatitis B virus (HBV) infection despite prophylaxis with hepatitis B immunoglobulin (HBIG) and lamivudine combination therapy is not easy. Because HBV reinfection has a severe course and could result in graft failure in liver transplant recipients, prompt medication is essential. Herein is reported the authors' experience with adefovir dipivoxil (AD) therapy in 11 liver transplant recipients who had HBV reinfection despite the administration of lamivudine and HBIG.

METHOD

Two-hundred and nine patients underwent liver transplantation (100 deceased donor liver transplantations [DDLT], 109 living donor liver transplantation [LDLT]) due to chronic hepatitis B infection between April 1997 and May 2005 in Ege University Medical School, Liver Transplantation Unit. Patients had prophylaxis with lamivudine and low-dose HBIG combination after liver transplantation. Treatment of recurrence consisted of AD 10 mg once a day and lamivudine 300 mg/daily and HBIG was discontinued in those patients.

RESULTS

In total there were 11 HBV recurrences: five occurred in DDLT recipients and six in LDLT recipients, at a median follow up of 18 months (range, 6-48 months). In one of 11 patients, pretransplant HBV-DNA and HBeAg were positive. Three patients had a severe course and one patient had fibrosing cholestatic hepatitis. After AD treatment, HBV-DNA level decreased in all patients and became negative in seven patients. Two patients died due to hepatocellular carcinoma recurrence after 12 and 14 months of follow up. Serum creatinine level increased mildly in one patient and no other side-effect was observed, and all patients continued therapy.

CONCLUSION

Adefovir dipivoxil is a safe, effective treatment option for post-transplant HBV recurrence even among patients with fibrosing cholestatic hepatitis caused by lamivudine-resistant HBV.

Liver transplantation for hepatitis B-related cirrhosis: recent advances

In the absence of preventative therapy, deceased-donor liver transplantation indicated for hepatitis B virus (HBV) cirrhosis results in dismal graft and patient survival due to HBV infection of the liver graft. Major advances in the management of HBV-infected recipients during the past 15 years have reduced the rate of graft infection, resulting in improved outcomes, comparable to those for patients transplanted for non-HBV indications. Long-term use of hepatitis B immunoglobulin for passive immunotherapy is effective in preventing re-infection. Combination therapy with hepatitis B immunoglobulin and lamivudine after liver transplantation reduces HBV recurrence. Adefovir dipoxil is a safe and effective alternative oral antiviral treatment for lamivudine-resistant mutant HBV. The high cost of hepatitis B immunoglobulin remains a problem that must be overcome by the development of HBV vaccines and potent adjuvants.

Five-year follow-up of a hepatitis B virus-positive recipient of hepatitis B surface antigen-positive living donor liver graft

The shortage of cadaveric donor organs has led to the use of living donors and marginal cadaveric donors. To date, there have been only 2 reports on the use of hepatitis B surface antigen (HBsAg)-positive liver grafts. Here we describe the 5-yr posttransplantation sequence of a hepatitis B virus (HBV)-positive recipient who received an HBsAg-positive living donor liver graft. A 43-yr-old HBV-positive patient with hepatorenal syndrome received a living donor liver graft in October 2000 from a 27-yr-old HBsAg-positive carrier with no clinical evidence of HBV infection other than the serologic markers. The recipient recovered slowly after liver transplantation (LT). Recipient serum HBsAg was continuously positive despite anti-HBV therapy with high-dose hepatitis B immunoglobulin (HBIG) and lamivudine. The patient was also treated with famciclovir and interferon; to date, a final regimen of lamivudine and adefovir has kept liver function stable for 20 months. The recipient has lived for 64 months after transplantation. The donor has not revealed any clinical evidence of active hepatitis during follow-up. In conclusion, our result implicates that a recipient of liver graft from an HBsAg-positive carrier may survive for a long period following antiviral therapy with lamivudine and adefovir. Considering this living donor case and previously reported cases, the use of an HBsAg-positive cadaveric liver graft may deserve attention when no other donor is available.

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'.

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.

Adefovir treatment in posttransplant hepatitis B virus infection resistant to lamivudine plus hepatitis B virus immunoglobulin

Failure of prophylaxis for hepatitis B virus (HBV) recurrence in liver transplant patients with HBV immunoglobulin (HBIG) or lamivudine or both can be associated with rapid development of liver failure. Some of these patients develop a devastating clinicopathological state characterized by jaundice and rapidly progressive liver failure or fibrosing cholestatic hepatitis. We present two liver transplant recipients who experienced HBV recurrence while they were under lamivudine and HBIG prophylaxis. One of them had finding of severe HBV infection; the other, fibrosing cholestatic hepatitis. After commencing adefovir dipivoxil both patients showed improvements in clinical status and laboratory data. At month 4 of treatment, HBV DNA values became negative and liver function tests almost normalized. In addition, in one case showed HBs ag/anti-HBs seroconversion. When failure of prophylaxis with lamivudine and HBIG occurs, adefovir dipivoxil should be considered to be a safe and effective choice for recurrent HBV infections in liver transplant patients.

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Outcome of liver transplantation for hepatitis B in the United States

Important innovations, such as hepatitis B immune globulin (HBIG) and lamivudine, have been introduced to the care of patients undergoing liver transplantation (OLT) for viral hepatitis B (HBV) (over the last 15 years). We analyzed survival of OLT recipients with HBV in the United States to examine the effect of these innovations. A retrospective analysis was conducted based on data collected prospectively by the United Network for Organ Sharing in all adult (older than 18) patients undergoing primary OLT in the United States between 1987 and 2002. OLT recipients with HBV were identified by the principal diagnosis of acute or chronic HBV or positive results on HBV markers. Patients were divided into Era 1 (1987-1991), Era 2 (1992-1996), and Era 3 (1997-2002). Era 1 consisted of 6,708 patients (675 with HBV), Era 2 consisted of 13,995 patients (1,005 with HBV), and Era 3 consisted of 20,730 patients (1,723 with HBV). More recent patients were older and had less advanced liver disease and shorter ischemic time. The survival of patients with HBV was significantly better for Era 2 than for Era 1 (P <.01) and for Era 3 than for Era 2 (P <.01). There was no difference in survival between patients with HBV and all other diagnoses for Era 3 (P =.14). In the multivariable analysis, the effect of these eras persisted when other variables such as recipient and donor age, warm ischemic time, pre-OLT disease severity, and hepatocellular carcinoma (HCC) were taken into account. Unlike previous reports, fulminant disease and Asian race had no effect on patient survival. In conclusion, these data underscore the effectiveness of therapeutic innovations that have occurred in the past two decades and indicate timely and widespread adoption of these measures by transplant centers nationwide.

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.

Impact of donor infections on outcome of orthotopic liver transplantation

Infection occurs when microbial agents enter the host, either through airborne transmission or by direct contact of a substance carrying the infectious agent with the host. Human body fluids, solid organs, or other tissues often are ideal vectors to support microbial agents and can transmit infections efficiently from donor to recipient. In the case of blood transfusion and tissue transplantation, the main consequence of such a transmission is infection of the recipient. However, in the case of solid-organ transplantation, and particularly for liver transplantation, donor infections are not only transmitted to the recipient, the donor infection also may affect the donated liver's preservability and subsequent function in the recipient irrespective of the systemic consequences of the infection. In addition, solid organ recipients of infected organs are less able to respond to the infectious agent because of their immunosuppressive treatment. Thus, transmission of infections from organ donor to liver recipient represents serious potential risks that must be weighed against a candidate's mortality risk without the transplant. However, the ever-increasing gap between the number of donors and those waiting for liver grafts makes consideration of every potential donor, regardless of the infection status, essential to minimize waiting list mortality. In this review, we will focus on assessing the risk of transmission of bacterial, fungal, viral, and parasitic infectious agents from cadaveric liver donors to recipients and the effect such a transmission has on liver function, morbidity, and mortality. We will also discuss risk-benefit deliberations for using organs from infected donors for certain types of recipients. These issues are critically important to maximize the use of donated organs but also minimize recipient morbidity and graft dysfunction.