Pharmaceutical management of hepatitis B and C in liver and kidney transplant recipients

Interferon-free regimens in patients with hepatitis C infection and renal dysfunction or kidney transplantation

Treatment of patients with chronic kidney disease (CKD) and chronic hepatitis C (CHC) differs from that used in the general CHC population mostly when glomerular filtration rate (GFR) is below 30 mL/min, as sofosbuvir, the backbone of several current regimens, is officially contraindicated. Given that ribavirin free regimens are preferable in CKD, elbasvir/grazoprevir is offered in CHC patients with genotype 1 or 4 and ombitasvir/paritaprevir and dasabuvir in genotype 1b for 12 wk. Although regimens containing peginterferon with or without ribavirin are officially recommended for patients with CKD and genotype 2, 3, 5, 6, such regimens are rarely used because of their low efficacy and the poor safety and tolerance profile. In this setting, especially in the presence of advanced liver disease, sofosbuvir-based regimens are often used, despite sofosbuvir contraindication. It seems to have good overall safety with only 6% or 3.4% of CKD patients to discontinue therapy or develop serious adverse events without drug discontinuation. In addition, sustained virological response (SVR) rates with sofosbuvir based regimens in CKD patients appear to be comparable with SVR rates in patients with normal renal function. Treatment recommendations for kidney transplant recipients are the same with those for patients with CHC, taking into consideration potential drug-drug interactions and baseline GFR before treatment initiation. This review summarizes recent data on the current management of CHC in CKD patients highlighting their strengths and weaknesses and determining their usefulness in clinical practice.

Tenofovir and kidney transplantation: case report

Background: Hepatitis B viral infection (HBV) has been regarded as a contraindication for kidney transplantation because of the high risk of viral activation induced by immunosuppressive therapy. Anti-retroviral drugs have changed the prognosis of patients with hepatitis B viral infection (HBV+) who are candidates for renal transplant; indeed, therapy with antiretroviral drugs may ensure lower rates of morbidity and mortality compared to traditional therapies. Entecavir is the first-line antiviral therapy recommended for the treatment of HBV+ kidney-transplanted patients. In case of resistance to entecavir, tenofovir may be an alternative drug, either alone or in combination with entecavir. However, the best strategy of treatment is still unknown. In this case-report, a HBV+ kidney-transplanted patient who presented resistance to entecavir was initially treated by associating tenofovir to entecavir and with tenofovir alone afterward. This strategy induced complete remission of viral replication. Case presentation: In a HBV+ kidney-transplanted patient under monotherapy with entecavir, HBV flare (HBV DNA > 170.000 × 10³ UI/mL, HBeAg+, HbeAb–) occurred 9 months after transplantation; at that time, blood chemistry highlighted: creatinine 1.46 mg/dL, blood urea 65 mg/dL, e-GFR 50 mL/min, proteinuria 300 mg/24 h, calciuria 2,12 mmol/24 h, phosphaturia 0.56 g/24 h, vitamin D 11.5 ng/mL, PTH 130 pg/mL, calcemia 2.3 mmol/L, and phosphoremia 2 mg/dL. Liver elastometry (FibroScan) showed moderate fibrosis. Tenofovir was associated to entecavir. Three months after the combination therapy, reduction in HBV DNA replication (351 × 10³ UI/mL) was obtained. Creatinine and e-GFR were 1.48 mg/dL and 52 mL/min, respectively. At this point, entecavir was discontinued. After 13 months of tenofovir monotherapy, complete remission of viral replication was achieved but renal function deteriorated and proteinuria increased. Conclusion: This case-report indicates that tenofovir is effective in reducing viral replication of hepatitis B virus in a kidney-transplanted patient who presented resistance to previous treatment with entecavir. However, it should be taken into account that tenofovir could affect renal function.

Hepatitis C Virus Infection in Chronic Kidney Disease

Soon after the hepatitis C virus (HCV) was identified in 1989, it was recognized that the prevalence of infection in patients with ESRD far exceeded that in the general population. Infection with HCV predisposes to the hepatic complications of cirrhosis and hepatocellular carcinoma. However, important extrahepatic manifestations include immune complex glomerular disease, accelerated progression of CKD, increases in cardiovascular event risk, and lymphoproliferative disorders. Advances in understanding the molecular biology of HCV have ushered in a new era in the treatment of this infection. Second generation direct-acting antiviral agents have revolutionized therapy, with sustained virologic response rates (undetectable viral load 12 weeks after completing therapy) of >90% in most patients. Studies using direct-acting antivirals in patients with CKD and those on dialysis are showing excellent safety and efficacy as well. In this context, it is imperative that nephrologists become familiar with this literature, reviewed here, so that the important decisions, including which patients should be treated and the optimal timing to initiate therapy, are vetted in association with the compounding issues of CKD, ESRD, and kidney transplantation.