Management of hepatitis B and C virus infection before and after renal transplantation

The Impact of Antiviral Treatment of Hepatitis B Virus after Kidney Transplant and the Latest Insights

BACKGROUND

The current frequency of hepatitis B virus infection in patients with advanced chronic kidney disease (CKD) (including patients on maintenance dialysis and kidney transplant recipients) is low but not negligible worldwide. HBV has a deleterious effect on survival after a kidney transplant; antiviral treatments improved the short-term outcomes of kidney transplant recipients, but their long-term impact remains uncertain.

AIM

The aim of this review is to assess the role of antiviral therapy for HBV in improving survival after a kidney transplant. The recent publication of large surveys has prompted us to update the available evidence on the impact of HBV on patient and graft survival after a kidney transplant.

METHODS

We have conducted an extensive review of the medical literature, and various research engines have been used.

RESULTS

We retrieved several studies (n = 11; n = 121,436 unique patients) and found an association between positive serologic HBsAg status and diminished patient and graft survival after a kidney transplant; the adjusted relative risk (aRR) of all-cause mortality and graft loss was 2.85 (95% CI, 2.36; 3.33, p < 0.0001) and 1.26 (95% CI, 1.02; 1.51, p < 0.0001), respectively. To our knowledge, at least six studies reported improved patient and graft survival after the adoption of antiviral therapies for HBV (this result was reported with both survival curves and multivariable regression). According to novel clinical guidelines, entecavir has been suggested as a 'first line' antiviral agent for the treatment of HBV after a kidney transplant.

CONCLUSIONS

The recent availability of safe and effective antiviral drugs for the treatment of HBV has meant that the survival curves of HBsAg-positive patients on antiviral therapy and HBsAg-negative patients after a kidney transplant can be comparable. Antiviral therapy should be systematically proposed to HBV-positive kidney transplant recipients and candidates to avoid the deleterious hepatic and extra-hepatic effects of chronic HBV replication.

Influence of donor and recipient hepatitis B virus infection on long-term outcomes after kidney transplantation

BACKGROUND

The demand for transplantable kidneys continues to outstrip supply, and the risk of donor-derived infection limits utilization. The effect of donor or recipient HBV status, defined by surface antigen (HBsAg) positivity, on long-term survival outcomes of kidney transplant (KT) is unknown.

METHODS

We conducted a retrospective cohort study based on Organ Procurement and Transplantation Network (OPTN) data from 2000 to 2019. We identified three cohorts based on donor (D) or recipient (R) HBsAg status: D-R, D-R+, and D+R-. Pairwise comparisons of patient survival (PS) and all-cause graft survival (GS) after propensity score matching were performed to assess the effect of HBV infection in KT recipients.

RESULTS

Our findings showed that there were no statistically significant differences in PS and GS among D-R, D-R+, and D+R-groups, nor was the patient or GS different between donor and recipient HBsAg+ status. Finally, in 2019 kidney discard rates were 15% higher for HBsAg+ deceased donors compared to HBsAg- donors.

CONCLUSIONS

HBsAg+ status was not associated with worse PS or GS after KT. Prior to broadly advocating utilization of HbsAg+ kidneys, further studies assessing KT recipient morbidity and safety are necessary.

Hepatitis B in renal transplant patients

Hepatitis B virus (HBV) poses a significant challenge for both dialysis patients and kidney transplant recipients despite its decreasing rates, especially in developed countries. The best preventive method is vaccination. Patients with chronic renal disease should ideally be vaccinated prior to dialysis, otherwise, reinforced vaccination practices and close antibody titer monitoring should be applied while on dialysis. HBV infected dialysis patients who are renal transplant candidates must be thoroughly examined by HBV-DNA, and liver enzyme testing and by liver biopsy. When needed, one must consider treating patients with tenofovir or entecavir rather than lamivudine. Depending on the cirrhosis stage, dialysis patients are eligible transplant recipients for either a combined kidney-liver procedure in the case of decompensated cirrhosis or a lone kidney transplantation since even compensated cirrhosis after sustained viral responders is no longer considered an absolute contraindication. Nucleoside analogues have led to improved transplantation outcomes with both long-term patient and graft survival rates nearing those of HBsAg(-) recipients. Moreover, in the cases of immunized HBsAg(-) potential recipients with concurrent prophylaxis, we are enabled today to safely use renal grafts from both HBsAg(+) and HBsAg(-)/anti-HBc(+) donors. In so doing, we avoid unnecessary organ discarding. Universal prophylaxis with entecavir is recommended in HBV kidney recipients and should start perioperatively. One of the most important issues in HBV(+) kidney transplantation is the duration of antiviral prophylaxis. In the absence of robust data, it seems that prophylactic treatment may be discontinued in selected stable, low-risk recipients during maintenance immunosuppression and should be reintroduced when the immune status is altered. All immunosuppressive agents in kidney transplantation can be used in HBV(+) recipients. Immunosuppression is intimately associated with increased viral replication; thus it is important to minimize the total immunosuppression burden long term.

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.

Interferon-based anti-viral therapy for hepatitis C virus infection after renal transplantation: an updated meta-analysis

BACKGROUND

Hepatitis C virus (HCV) infection is highly prevalent in renal transplant (RT) recipients. Currently, interferon-based (IFN-based) antiviral therapies are the standard approach to control HCV infection. In a post-transplantation setting, however, IFN-based therapies appear to have limited efficacy and their use remains controversial. The present study aimed to evaluate the efficacy and safety of IFN-based therapies for HCV infection post RT.

METHODS

We searched Pubmed, Embase, Web of Knowledge, and The Cochrane Library (1997-2013) for clinical trials in which transplant patients were given Interferon (IFN), pegylated interferon (PEG), interferon plus ribavirin (IFN-RIB), or pegylated interferon plus ribavirin (PEG-RIB). The Sustained Virological Response (SVR) and/or drop-out rates were the primary outcomes. Summary estimates were calculated using the random-effects model of DerSimonian and Laird, with heterogeneity and sensitivity analysis.

RESULTS

We identified 12 clinical trials (140 patients in total). The summary estimate for SVR rate, drop-out rate and graft rejection rate was 26.6% (95%CI, 15.0-38.1%), 21.1% (95% CI, 10.9-31.2%) and 4% (95%CI: 0.8%-7.1%), respectively. The overall SVR rate in PEG-based and standard IFN-based therapy was 40.6% (24/59) and 20.9% (17/81), respectively. The most frequent side-effect requiring discontinuation of treatment was graft dysfunction (14 cases, 45.1%). Meta-regression analysis showed the covariates included contribute to the heterogeneity in the SVR logit rate, but not in the drop-out logit rate. The sensitivity analyses by the random model yielded very similar results to the fixed-effects model.

CONCLUSIONS

IFN-based therapy for HCV infection post RT has poor efficacy and limited safety. PEG-based therapy is a more effective approach for treating HCV infection post-RT than standard IFN-based therapy. Future research is required to develop novel strategies to improve therapeutic efficacy and tolerability, and reduce the liver-related morbidity and mortality in this important patient population.

Treatment of hepatitis B in patients with chronic kidney disease

Although the prevalence of chronic hepatitis B virus (HBV) infection in patients with chronic kidney disease remains low in developed countries, clinicians should be aware of the rationale for treatment in this setting. This patient population presents particular features and various complicating conditions requiring special treatment strategies. Interferon, the standard treatment for HBV infection, has been poorly tolerated by patients with chronic kidney disease, has presented relatively low efficacy, and has posed renal transplant recipients under the risk of acute rejection. The advent of effective nucleos(t)ide analogs (NAs) has offered the opportunity to minimize the consequences of HBV infection in HBV-positive patients with chronic kidney disease. Combination with immunosuppressive agents might be considered in cases of rapid renal function deterioration and/or severe proteinuria. Among the newer NAs, entecavir may be preferred, because of its high potency, high genetic barrier to resistance, and favorable renal safety profile. However, entecavir presented low efficacy in case of lamivudine or telbivudine resistance, and thus tenofovir may be a better option in that setting. All HBsAg-positive candidates should be treated with NAs before renal transplantation in order to maintain undetectable HBV DNA, reduce liver fibrosis, and prevent hepatic decompensation after renal transplantation. This review summarizes updated issues related to treatment of chronic HBV infection in all categories of population with chronic kidney disease (those exhibiting HBV-associated glomerular disease, those treated with hemodialysis, as well as renal transplant candidates, donors, and recipients).

Viral infection in renal transplant recipients

Viruses are among the most common causes of opportunistic infection after transplantation. The risk for viral infection is a function of the specific virus encountered, the intensity of immune suppression used to prevent graft rejection, and other host factors governing susceptibility. Although cytomegalovirus is the most common opportunistic pathogen seen in transplant recipients, numerous other viruses have also affected outcomes. In some cases, preventive measures such as pretransplant screening, prophylactic antiviral therapy, or posttransplant viral monitoring may limit the impact of these infections. Recent advances in laboratory monitoring and antiviral therapy have improved outcomes. Studies of viral latency, reactivation, and the cellular effects of viral infection will provide clues for future strategies in prevention and treatment of viral infections. This paper will summarize the major viral infections seen following transplant and discuss strategies for prevention and management of these potential pathogens.

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.

Hepatitis C and renal transplantation: a review on historical aspects and current issues

Chronic liver disease has a significant impact on the survival of renal transplant recipients with an incidence rate of 4-38%. Approximately, 8-28% of renal transplant recipients die due to chronic liver disease. Hepatitis C seems to be the leading cause of chronic liver disease in kidney recipients. Hepatitis C virus (HCV) infection has a wide range of prevalence (2.6-66%) among renal transplant recipients living in different countries with great genotype diversity in different parts of the world. Nowadays, antiviral drugs are used for the management of hepatitis C. Because of graft-threatening effects of some antiviral drugs used in HCV-infected renal transplant recipients, we specifically focused on HCV treatment after renal transplantation. Treatment of post-renal transplantation chronic liver disease with INF and ribavirin remains controversial. Anecdotal reports on post-renal transplantation hepatitis C demonstrate encouraging findings. This review summarises the most current information on diagnosis, treatment, prognosis, complications as well as the new aspects of treatment in HCV-infected renal transplant recipients. HCV belongs to the family of Flaviviridae, genus Hepacivirus.

Hepatitis C virus and kidney disease

Hepatitis C virus (HCV) infection remains frequent in patients on renal replacement therapy and has an adverse impact on survival in infected patients on chronic hemodialysis as well as renal transplant (RT) recipients. Nosocomial spread of HCV within dialysis units continues to occur. HCV is also implicated in the pathogenesis of renal dysfunction often mediated by cryoglobulins leading to chronic kidney disease as well as impairing renal allograft function. The role of antiviral therapy for hepatitis C in patients with renal failure remains unclear. Monotherapy with conventional interferon (IFN) for chronic hepatitis C is probably more effective in dialysis than in non-uraemic patients but tolerance is lower. Limited data only are available about monotherapy with pegylated interferon and combination therapy (pegylated IFN plus ribavirin) for chronic HCV in the dialysis population. Clinical experience with antiviral therapy for acute HCV in dialysis population is encouraging. Interferon remains contraindicated post-RT because of concerns about precipitating graft dysfunction. Sustained viral responses obtained by antiviral therapy in renal transplant candidates are durable after renal transplantation and may reduce HCV-related complications after RT (post-transplant diabetes mellitus, HCV-related glomerulonephritis, and chronic allograft nephropathy).