Antiviral prophylaxis for the prevention of chronic hepatitis C virus in patients undergoing liver transplantation

Revolution in the diagnosis and management of hepatitis C virus infection in current era

Chronic hepatitis C virus (HCV) infection is a major global public health problem, particularly in developing part of the world. Significant advances have been made in the early diagnosis and treatment of the disease. Its management has been particularly revolutionized during the past two decades. In this review, we summarize the major advances in the diagnostic and management armamentarium for chronic HCV infection. The focus of the present review is on the newer directly acting anti-viral agents, which have revolutionized the management of chronic HCV infection. Management of uncomplicated chronic HCV infection and of specific complications and special at-risk populations of patients will be covered in detail. Despite the advent and approval of highly effective and well tolerable oral agents, still many challenges remain, particularly the affordability, the equitable distribution and access to later drugs. The World Health Organization aims to eliminate viral hepatitis including HCV by 2030 since its poses a major public health threat. There is an urgent need to ensure uniform and early access to diagnostic and therapeutic facilities throughout the world if the later goal has to be realized.

Sofosbuvir and Ribavirin for 24 Weeks Is An Effective Treatment Option for Recurrent Hepatitis C Infection After Living Donor Liver Transplantation

BACKGROUND

Recurrent hepatitis C virus (HCV) has been a serious problem after liver transplantation (LT). We report our experience of 24-week therapy with sofosbuvir (SOF) and ribavirin (RBV) in post-LT recurrent HCV in living donor liver transplantation (LDLT) setting in South Asia.

METHODS

Data from all patients treated for post-transplantation HCV recurrence in a single center were analyzed. Treatment regimen was 24 weeks of SOF 400 mg daily and RBV (starting at 800 mg daily, increased as tolerated). Sustained virological response (SVR) was assessed 12 weeks and 24 weeks after completion of treatment.

RESULTS

63 patients (median age 52 [range 30-69] years; 80% males) were treated. Most (76.2%) were treatment experienced and predominant HCV genotype was 3 (77.7%) followed by 1 (20.6%). Median transient elastography (Fibroscan) score was 7 (range 3-11) kPa and none of the patients had cirrhosis. SVR12 was achieved in 60 of 63 patients (95.2%) while SVR24 was noted in 59 (93.7%). SVR12 rates were as good in genotype-3 as in genotype-1. Older age, longer period after transplantation, higher Fibroscan value and higher need for erythropoietin were likely to be associated with relapse. Adverse effects were noted in 34 patients and weakness and fatigue were the commonest side effects. Significant drop in hemoglobin (<8 g/dL) was seen in 6 patients.

CONCLUSIONS

SOF + RBV combination therapy for 24 weeks was safe and effective in treatment of for post-LT recurrent HCV in a single LT center and remains relevant due to its low cost and lack of drug interactions.

Host cell mTORC1 is required for HCV RNA replication

OBJECTIVE

Chronically HCV-infected orthotopic liver transplantation (OLT) recipients appear to have improved outcomes when their immunosuppressive regimen includes a mammalian target of rapamycin (mTOR) inhibitor. The mechanism underlying this observation is unknown.

DESIGN

We used virological assays to investigate mTOR signalling on the HCV replication cycle. Furthermore, we analysed HCV RNA levels of 42 HCV-positive transplanted patients treated with an mTOR inhibitor as part of their immunosuppressive regimen.

RESULTS

The mTOR inhibitor rapamycin was found to be a potent inhibitor for HCV RNA replication in Huh-7.5 cells as well as primary human hepatocytes. Half-maximal inhibition was observed at 0.01 µg/mL, a concentration that is in the range of serum levels seen in transplant recipients and does not affect cell proliferation. Early replication cycle steps such as cell entry and RNA translation were not affected. Knockdown of raptor, an essential component of mTORC1, but not rictor, an essential component of mTORC2, inhibited viral RNA replication. In addition, overexpression of raptor led to higher viral RNA replication, demonstrating that mTORC1, but not mTORC2, is required for HCV RNA replication. In 42 HCV-infected liver-transplanted or kidney-transplanted patients who were switched to an mTOR inhibitor, we could verify that mTOR inhibition decreased HCV RNA levels in vivo.

CONCLUSIONS

Our data identify mTORC1 as a novel HCV replication factor. These findings suggest an underlying mechanism for the observed benefits of mTOR inhibition in HCV-positive OLT recipients and potentiate further investigation of mTOR-containing regimens in HCV-positive recipients of solid organ transplants.

Overview and recent trends of systematic reviews and meta-analyses in hepatology

A systematic review (SR) is a research methodology that involves a comprehensive search for and analysis of relevant studies on a specific topic. A strict and objective research process is conducted that comprises a systematic and comprehensive literature search in accordance with predetermined inclusion/exclusion criteria, and an assessment of the risk of bias of the selected literature. SRs require a multidisciplinary approach that necessitates cooperation with clinical experts, methodologists, other experts, and statisticians. A meta-analysis (MA) is a statistical method of quantitatively synthesizing data, where possible, from the primary literature selected for the SR. Review articles differ from SRs in that they lack a systematic methodology such as a literature search, selection of studies according to strict criteria, assessment of risk bias, and synthesis of the study results. The importance of evidence-based medicine (EBM) in the decision-making for public policy has recently been increasing thanks to the realization that it should be based on scientific research data. SRs and MAs are essential for EBM strategy and evidence-based clinical practice guidelines. This review addresses the current trends in SRs and MAs in the field of hepatology via a search of recently published articles in the Cochrane Library and Ovid-MEDLINE.

Management of Hepatitis C Before and After Liver Transplantation in the Era of Rapidly Evolving Therapeutic Advances

Management of hepatitis C (HCV) in liver transplantation (LT) population presents unique challenges. Suboptimal graft survival in HCV+ LT recipients is attributable to universal HCV recurrence following LT. Although eradication of HCV prior to LT is ideal for the prevention of HCV recurrence it is often limited by adverse events, particularly in patients with advanced cirrhosis. Antiviral therapy in LT candidates needs careful monitoring, and prophylaxis with HCV antibodies is ineffective. Early antiviral therapy after LT has been investigated, but no clear benefit has been demonstrated. Protocol liver biopsy is generally recommended in HCV+ LT recipients, and antiviral therapy can be considered in those with severe/progressive HCV recurrence. Sustained virological response (SVR) can be achieved in approximately 30% of LT recipients with pegylated interferon/ribavirin (PEG-IFN/RBV) with survival benefit, but adverse effects are common. Favorable patient characteristics for response to therapy include non-1 genotype, previously untreated, low baseline HCV-RNA, and donor IL28B genotype CC. Direct acting antiviral (DAA)-based triple therapy is associated with higher rates of SVR, but with similar or slightly higher rates of side effects, and immunosuppressive regimens need to be closely monitored and adjusted during the treatment period. Notably, the safety and efficacy of HCV treatment are very likely to improve with newer generation DAA. The benefit of immunosuppressive strategy on the natural history HCV recurrence has not been well elucidated. Based upon available evidence, cyclosporine A (CSA), mycophenolate mofetil (MMF), and sirolimus appear to have a neutral or small beneficial impact on HCV recurrence. Donor interleukin 28 B (IL28B) polymorphisms appear to impact the course and treatment outcomes in recurrent HCV. Retransplantation should be considered for patients with reasonable survival probability.

Antiviral interventions for liver transplant patients with recurrent graft infection due to hepatitis C virus

BACKGROUND

Antiviral therapy for recurrent hepatitis C infection after liver transplantation is controversial due to unresolved balance between benefits and harms.

OBJECTIVES

To compare the therapeutic benefits and harms of different antiviral regimens in patients with hepatitis C re-infected grafts after liver transplantation.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; Issue 1, 2013), MEDLINE, EMBASE, and Science Citation Index Expanded to February 2013.

SELECTION CRITERIA

We considered only randomised clinical trials (irrespective of language, blinding, or publication status) comparing various antiviral therapies (alone or in combination) in the treatment of hepatitis C virus recurrence in liver transplantation for the review.

DATA COLLECTION AND ANALYSIS

Two authors collected the data independently. We calculated the risk ratio (RR) or mean difference (MD) with 95% confidence intervals (CI) using the fixed-effect and the random-effects models based on available case-analysis. In the presence of only trials for a dichotomous outcome, we performed the Fisher's exact test.

MAIN RESULTS

Overall, 17 trials with 736 patients met the inclusion criteria for this review. All trials had high risk of bias. Five hundred and one patients randomised in 11 trials provided information for various comparisons in this systematic review after excluding post-randomisation drop-outs and patients from trials that did not report any of the outcomes of interest for this review. The comparisons for which outcomes were available included pegylated (peg) interferon versus control; peg interferon plus ribavirin versus control; ribavirin plus peg interferon versus peg interferon; peg interferon (1.5 μg/kg/week) plus ribavirin versus peg interferon (0.5 μg/kg/week) plus ribavirin; amantadine plus peg interferon plus ribavirin versus peg interferon plus ribavirin; interferon versus control; interferon plus ribavirin versus control; ribavirin versus interferon; and ribavirin versus placebo. Long-term follow-up was not available in these trials. There were no significant differences in mortality, retransplantation, graft rejections requiring retransplantation or medical treatment, or fibrosis worsening between the groups in any of the comparisons in which these outcomes were reported. Quality of life and liver decompensation were not reported in any of the trials. There was a significantly higher proportion of participants who developed serious adverse events in the ribavirin plus peg interferon combination therapy group than in the peg interferon monotherapy group (1 trial; 56 participants; 17/28 (60.7%) in the intervention group versus 5/28 (17.9%) in the control group; RR 3.40; 95% CI 1.46 to 7.94). There was no significant difference in proportion of participants who developed serious adverse events or in the number of serious adverse events between the intervention and control groups in the other comparisons that reported serious adverse events.

AUTHORS' CONCLUSIONS

Considering the lack of clinical benefit, there is currently no evidence to recommend or refute antiviral treatment for recurrent liver graft infection with hepatitis C virus. Further randomised clinical trials with low risk of bias and low risk of random errors with adequate duration of follow-up are necessary.