Treatment with adefovir dipivoxil in a renal transplant patient with renal insufficiency and lamivudine-resistant hepatitis B infection

Antiviral treatment for chronic hepatitis B in renal transplant patients

Chronic hepatitis B infection is frequent in renal transplant patients. It negatively impacts long term outcomes reducing graft and patient survival. Current guidelines clearly define who needs treatment, when to start, what is the first line therapy, how to monitor treatment response, when to stop, and how patients must be controlled for its safety. There is some data showing a favorable safety and efficacy profile of nucleos(t)ide analogue (NUC) treatment in the renal transplant setting. Entecavir, a drug without major signs of nephrotoxicity, appears to be the first option for NUC naïve patients and tenofovir remains the preferred choice for patients with previous resistance to lamivudine or any other NUC. Renal transplant recipients under antiHBV therapy should be monitored for its efficacy against HBV but also for its safety with a close renal monitoring. Studies including a large number of patients with long term treatment and follow up are still needed to better demonstrate the safety and efficacy of newer NUCs in this population.

Evolution of hepatitis B management in kidney transplantation

Chronic hepatitis B virus (HBV) infection adversely influences the clinical outcomes of renal transplant recipients owing to increased hepatic complications. Management of HBV infection in kidney transplant recipients presents a challenge to clinicians, especially in endemic regions. Interferon precipitates renal allograft dysfunction. Treatment with lamivudine, the first oral nucleoside analogue available, resulted in effective viral suppression, reduced liver-related complications, and improved patient survival so that medium-term data showed comparable patient survival rates between hepatitis B surface antigen-positive and HBsAg-negative kidney transplant recipients in the era of effective antiviral therapies. Entecavir has replaced lamivudine as first-line therapy for treatment-naïve subjects in view of the propensity for drug resistance with the latter. Management of HBV infection in kidney transplant patients needs to take into consideration the nephrotoxicity of nucleoside/tide analogues such as adefovir and tenofovir. Prevention of HBV-related complications in kidney transplant recipients starts much earlier prior to transplantation, with vaccination of patients with chronic kidney disease and donor-recipient matching with regard to HBV status. In addition to anti-viral treatment, patients with chronic HBV infection must have regular surveillance for liver cancer and assessment for the development of cirrhosis.

Review article: nucleos(t)ide analogues in patients with chronic hepatitis B virus infection and chronic kidney disease

BACKGROUND

The treatment of chronic hepatitis B (CHB) in patients with chronic kidney disease (CKD) is based on nucleoside (lamivudine, telbivudine, entecavir) or nucleotide (adefovir, tenofovir) analogues (NAs), but it may be complex and the information is scarce. Entecavir and tenofovir represent the currently recommended first-line NAs for NA-naive CHB patients, while tenofovir is the NA of choice for CHB patients with resistance to nucleosides.

AIM

To review the efficacy and safety of NAs in adult CHB patients with CKD and to provide reasonable recommendations for their optimal management.

METHODS

Literature search in PubMed/Medline and manual search of relevant articles, reviews and book chapters.

RESULTS

NAs are cleared by kidneys and their dosage should be adjusted in patients with creatinine clearance <50 mL/min. There are concerns about nephrotoxic potential of the nucleotides, particularly adefovir, while improvements of creatinine clearance have been reported under telbivudine. Most existing data in CHB patients with CKD are for lamivudine and, less frequently, for other NAs, mostly entecavir. Besides CHB, NA should be used in case of immunosuppressive therapy in any HBsAg-positive patient with CKD including renal transplant (RT) recipients and in anti-HBs-positive recipients of kidney grafts from HBsAg-positive donors.

CONCLUSIONS

Chronic hepatitis B patients with chronic kidney disease receiving nucleoside analogues should be followed carefully for treatment efficacy and renal safety. Despite the absence of strong data, entecavir and telbivudine seem to be the preferred options for nucleoside analogue-naive CHB patients with chronic kidney disease, depending on viraemia and severity of renal dysfunction. More studies are certainly needed in this setting.

Hepatitis B virus and renal transplantation

Hepatitis B virus (HBV) infection remains an important cause of liver disease in the renal transplant (RT) population, potentially diminishing survival. Consequences of HBV infection after RT include progression to decompensated cirrhosis and an increased risk of hepatocellular carcinoma. Although precautions initially recommended by the Centers for Diseases Control and Prevention 30 years ago have substantially reduced HBV transmission within hemodialysis units, acute HBV outbreaks continue to be reported in patients with chronic kidney disease on maintenance hemodialysis. In addition, immigration from areas of high HBV prevalence implies that HBV-infected organs with chronic kidney disease will continue to enter the RT pool. Fortunately, the advent of oral therapy for HBV infection now reduces the risk of HBV progression post-RT.

Long-term outcome of renal transplant recipients with chronic hepatitis B infection-impact of antiviral treatments

BACKGROUND

Antiviral treatment has improved the short-term outcome of kidney transplant recipients with chronic hepatitis B infection, but its long-term impact, especially in patients who have developed drug resistance, remains uncertain.

METHODS

Sixty-three hepatitis B surface antigen positive (HBsAg+) and 63 HBsAg- patients who have undergone kidney transplantation from 1985 to 2008 were retrospectively reviewed and their clinical outcomes were compared.

RESULTS

With lamivudine as initial treatment, 62% of patients developed drug resistance after 4 years. Lamivudine resistance was associated with a higher incidence of chronic hepatitis but had no significant impact on liver stiffness score or patient survival during follow-up. Salvage treatment with adefovir or entecavir was well tolerated, and resulted in a three-log decrease in hepatitis B deoxynucleic acid after 6 months and normalization of alanine aminotransferase in 75% of patients. The survival rate of HBsAg+ patients transplanted in the recent era of antiviral treatment was 81% at 10 years. Treatment of hepatitis B with nucleoside/nucleotide analogues resulted in significantly improved patient survival (83% vs. 34% at 20 years, P=0.006). Although antiviral treatment was associated with reduced mortality because of liver complications (P=0.036), liver-related deaths still accounted for 40% of mortalities in HBsAg+ patients in the era of antiviral therapies and 22.2% of all deaths that occurred in patients who had received antiviral treatment.

CONCLUSION

Treatment of HBsAg+ renal transplant recipients with nucleoside/nucleotide analogues confers long-term survival benefit, and that rescue therapy with adefovir or entecavir is effective and well tolerated in patients who had developed resistance to lamivudine.

Response to adefovir or entecavir in renal allograft recipients with hepatitic flare due to lamivudine-resistant hepatitis B

We studied the effects of adefovir or entecavir in six kidney transplant recipients (mean age 45.7 +/- 7.8 yr) who developed hepatitic flare due to lamivudine-resistant hepatitis B virus (HBV) infection, with 18 months of follow-up. All patients had elevated alanine aminotransferase (ALT) levels and HBV DNA >10(5) copies/mL (median 2.15 x 10(8) copies/mL) at baseline. Serum creatinine and creatinine clearance levels were 137.8 +/- 59.7 mumol/L and 62.6 +/- 18.7 mL/min, respectively. Four patients were treated with adefovir and two with entecavir. Median HBV DNA decreased to 1.99 x 10(5) copies/mL (p = 0.028) after six months, 1.5 x 10(4) copies/mL (p = 0.043) after 12 months, and 7.35 x 10(4) copies/mL (p = 0.068) after 18 months of treatment. There was a corresponding improvement in ALT (34.5 +/- 19.1 U/L after 18 months, p = 0.029 compared with baseline). The rate of HBV DNA suppression was variable, and three patients took over six months for the viral load to decrease to <10(5) copies/mL. After 18 months, HBV DNA was <10(5) copies/mL in four patients and <10(2) copies/mL in one patient. Treatment was well-tolerated and renal function remained stable. We conclude that both adefovir and entecavir are effective in the treatment of lamivudine-resistant HBV in renal allograft recipients, and the reduction of HBV DNA to <10(5) copies/mL could be slow.

Treatment of lamivudine-resistant hepatitis B infection in post-renal transplant patients with adefovir dipivoxil: preliminary results

We report the treatment outcome in six post-renal transplant patients with lamivudine-resistant hepatitis B virus (LR-HBV) infection using adefovir dipivoxil and followed for 6 to 18 months. Posttransplant immunosuppressive therapy was not altered. Adefovir dipivoxil effectively suppressed hepatitis B virus DNA and improved alanine transferase, although DNA suppression seemed dependent on continued therapy. Nephrotoxicity led to withdrawal of the drug in three patients. This may limit therapeutic usefulness in a significant proportion of post-renal transplant patients with LR-HBV infection.