Host and virological features of HCV infection in liver transplant setting

Cirrhosis due to hepatitis C (HCV) infection, with or without hepatocellular carcinoma (HCC), is the leading indication for liver transplantation (LT) worldwide. Recurrent HCV infection of the allograft is universal if the virus is detectable at the time of transplant, with variable clinical course. In one third of liver recipients recurrent HCV infection lead to cirrhosis in the graft within only 5 years after LT. A small proportion of recipients can develop cholestatic HCV (CHC), a severe form of recurrence carrying a poor prognosis. In the last years, the approval of interferon-free (IFN-free) regimens for the treatment of chronic HCV has been a major step forward in Transplant Hepatology. The safety and efficacy of direct acting antivirals (DAAs) allow to treat patients awaiting LT as well as individuals with HCV recurrence after LT. Here we present two studies including HCV-infected patients in the peri-transplant setting. In the first study we aimed to assess the persistence of HCV-RNA in liver explants of HCV-infected patients treated with an IFN-free regimen on the waitlist for LT, and to analyze if its presence was associated with relapse after LT. Moreover, we investigated the potential role of the innate immune response on the persistence of HCV-RNA in the liver. Residual HCV-RNA was detected in liver explant in 67% of HCV-infected patients treated with DAAs on the waitlist, and with serum HCV-RNA negative at transplant. Nevertheless, HCV-RNA persistence in liver explant does not seem to be associated with virological relapse after transplantation, except in cases where liver HCV-RNA concentrations are high. Interestingly, we also found that the intrahepatic IFN pathway is down-regulated in patients treated with DAAs. In the second study we investigated virological mechanisms involved in the pathogenesis of cholestatic HCV (CHC) after LT, assessing the HCV quasispecies evolution and presence of specific mutations within the NS5B region, before and after LT, using ultra-deep pyrosequencing. Patients included in this study were at the extreme spectrum of hepatitis C recurrence: mild disease with an excellent long-term outcome and patients with CHC with a poor outcome. We showed that in patients with CHC, the predominant virus strain outgrow the others and generates a relatively uniform quasispecies. In these patients, HCV appears to acquire an increased fitness in the new graft, since we found that the master sequence present before LT propagated in most of CHC patients after LT, but not in patients with mild HCV recurrence. We cannot exclude that specific mutations within HCV genome of patients with CHC may explain the high viral replication capacity and fitness. Indeed, we found specific mutations in the HCV genome of some patients with CHC, but our sample was not sized to show significant differences with individuals with mild hepatitis C recurrence. A further step forward could be to introduce these mutations in in vitro models to test their impact on virus replication/fitness. In conclusion, the antiviral treatment of hepatitis C infection with DAAs before liver transplantation seems the ideal option in the liver transplant setting. However, in patients treated with DAAs on the waiting list, who have high explant HCV-RNA concentrations and a downregulation of IFN-pathway, another therapeutic strategy should be choose in order to avoid HCV recurrence after LT. In patients who develop a cholestatic hepatitis C recurrence after LT, the application of specific mutations of HCV polymerase gene in in vitro models might be crucial for a better understanding of the mechanisms underlying this severe form of HCV recurrence

Liver transplantation for viral hepatitis in 2015

Liver transplantation (LT) is a life-saving treatment for patients with end-stage liver disease and for patients with liver cell cancer related to liver disease. Acute and chronic liver diseases related to hepatitis viruses are between the main indications for liver transplantation. The risk of viral reinfection after transplantation is the main limiting factor in these indications. Before the availability of antiviral prophylaxis, hepatitis B virus (HBV) recurrence was universal in patients who were HBV DNA-positive before transplantation. The natural history of recurrent HBV was accelerated by immunosuppression, and it progressed rapidly to graft failure and death. Introduction of post-transplant prophylaxis with immunoglobulin alone first, and associated to antiviral drugs later, drastically reduced HBV recurrence, resulting in excellent long-term outcomes. On the contrary, recurrence of hepatitis C is the main cause of graft loss in most transplant programs. Overall, patient and graft survival after LT for hepatitis C virus (HCV)-associated cirrhosis is inferior compared with other indications. However, successful pretransplant or post transplant antiviral therapy has been associated with increased graft and overall survival. Until recently, the combination of pegylated interferon and ribavirin was the standard of care for the treatment of patients with chronic hepatitis C. Highly active antiviral compounds have been developed over the past decade, thanks to new in vitro systems to study HCV entry, replication, assembly, and release

Hepatitis C virus related cirrhosis decreased as indication to liver transplantation since the introduction of direct-acting antivirals: A single-center study

AIM: To evaluate waiting list (WL) registration and liver transplantation (LT) rates in patients with hepatitis C virus (HCV)-related cirrhosis since the introduction of direct-acting antivirals (DAAs). METHODS: All adult patients with cirrhosis listed for LT at Padua University Hospital between 2006-2017 were retrospectively collected using a prospectively-updated database; patients with HCV-related cirrhosis were divided by indication for LT [dec-HCV vs HCV/ hepatocellular carcinoma (HCC)] and into two interval times (2006-2013 and 2014-2017) according to the introduction of DAAs. For each patient, indications to LT, severity of liver dysfunction and the outcome in the WL were assessed and compared between the two different time periods. For patients receiving DAA-based regimens, the achievement of viral eradication and the outcome were also evaluated. RESULTS: One thousand one hundred and ninty-four [male (M)/female (F): 925/269] patients were included. Considering the whole cohort, HCV-related cirrhosis was the main etiology at the time of WL registration (490/1194 patients, 41%). HCV-related cirrhosis significantly decreased as indication to WL registration after DAA introduction (from 43.3% in 2006-2013 to 37.2% in 2014-2017, P = 0.05), especially amongst dec-HCV (from 24.2% in 2006-2013 to 15.9% in 2014-2017, P = 0.007). Even HCV remained the most common indication to LT over time (289/666, 43.4%), there was a trend towards a decrease after DAAs introduction (from 46.3% in 2006-2013 to 39% in 2014-2017, P = 0.06). HCV patients (M/F: 43/11, mean age: 57.7 \ub1 8 years) who achieved viral eradication in the WL had better transplant-free survival (log-rank test P = 0.02) and delisting rate (P = 0.002) than untreated HCV patients. CONCLUSION: Introduction of DAAs significantly reduced WL registrations for HCV related cirrhosis, especially in the setting of decompensated cirrhosis

Management of bacterial infection in the liver transplant candidate

Bacterial infection (BI) is a common cause of impairment of liver function in patients with cirrhosis, especially in the liver transplant candidates. These patients share an immunocompromised state and increased susceptibility to develop community and hospital-acquired infections. The changing epidemiology of BI, with an increase of multidrug resistant strains, especially in healthcare-associated settings, represents a critical issue both in the waiting list and in the post-operative management. This review focused on the role played by BI in patients awaiting liver transplantation, evaluating the risk of drop-out from the waiting list, the possibility to undergo liver transplantation after recovery from infection or during a controlled infection

Neuropsychiatric performance and treatment of hepatitis C with direct-acting antivirals: a prospective study

Background: Since direct-acting antivirals (DAAs) have been approved for the treatment of hepatitis C virus (HCV) infection, a small series of patients with new-onset neuropsychiatric alterations have been referred to us. We therefore set out to study neuropsychiatric function in relation to DAAs prospectively. Methods: Ten patients with cirrhosis and 12 post-liver transplant (post-LT) patients were enrolled. All underwent wake electroencephalography (EEG) and a neuropsychological evaluation (paper and pencil battery, simple/choice reaction times, working memory task) at baseline, at the end of treatment with DAAs and after 6 months. At the same time points, full blood count, liver/kidney function tests, quantitative HCV RNA, ammonia and immunosuppressant drug levels were obtained, as appropriate. Results: Patients with cirrhosis were significantly older than post-LT patients (65\ub112 vs 55\ub17 years; P<0.05). Neuropsychological performance and wake EEG were comparable in the two groups at baseline. At the end of a course of treatment with DAAs, a significant slowing in choice reaction times and in the EEG (increased relative delta power) was observed in patients with cirrhosis, which resolved after 6 months. In contrast, no significant changes over time were observed in the neuropsychiatric performance of post-LT patients. No significant associations were observed between neuropsychiatric performance and stand-alone/combined laboratory variables. Conclusion: Some degree of neuropsychiatric impairment was observed in relation to treatment with DAAs in patients with cirrhosis, but not in post-LT patients, suggesting that the former may be sensitive to mild DAA neurotoxicity

Polyclonal and monoclonal B lymphocytes response in HCV-infected patients treated with direct-acting antiviral agents

Hepatitis C virus (HCV) chronic infection can be associated with extrahepatic manifestations such as mixed cryoglobulinaemia and lymphoproliferative disorders that are endowed with increased rates of morbidity and all-cause mortality. In this study, we used flow cytometry to evaluate the effect of interferon-free antiviral treatment on peripheral blood lymphocytes in HCV-infected patients with or without associated lymphoproliferative disorders. Flow cytometry analysis of peripheral blood lymphocytes was performed at baseline and at the end of treatment. In HCV-infected patients with lymphoproliferative disorders, we evaluated immunoglobulin (Ig) light chain \u3ba/\u3bb ratio variations as a measure of monoclonal B-cell response to antiviral therapy. Healthy volunteers were enrolled as controls. A total of 29 patients were included, nine with and 20 without lymphoproliferative disorders. Sustained virological response was achieved in 29 of 29 patients. We observed a significant reduction in the B-cell compartment (39% global reduction) in eight of nine HCV-infected patients with lymphoproliferative disorders after viral clearance. We recognized the same trend, even if less pronounced, in HCV-infected patients without lymphoproliferative disorders (9% global reduction). Among HCV-infected patients with lymphoproliferative disorders, three showed an improvement/normalization of the immunoglobulin light chain ratio, whereas in the remaining six patients monoclonal B cells persisted to be clonally restricted even 1\ua0year after the end of treatment. Our data show that DAAs treatment can be effective in reducing the frequency of pathological B cells in the peripheral blood of HCV-infected patients affected by HCV-associated lymphoproliferative disorders; however, monoclonal populations can persist after viral eradication

Platelets and Hepatocellular Cancer: Bridging the Bench to the Clinics

Growing interest is recently being focused on the role played by the platelets in favoring hepatocellular cancer (HCC) growth and dissemination. The present review reports in detail both the experimental and clinical evidence published on this topic. Several growth factors and angiogenic molecules specifically secreted by platelets are directly connected with tumor progression and neo-angiogenesis. Among them, we can list the platelet-derived growth factor, the vascular endothelial growth factor, the endothelial growth factor, and serotonin. Platelets are also involved in tumor spread, favoring endothelium permeabilization and tumor cells\u2019 extravasation and survival in the bloodstream. From the bench to the clinics, all of these aspects were also investigated in clinical series, showing an evident correlation between platelet count and size of HCC, tumor biological behavior, metastatic spread, and overall survival rates. Moreover, a better understanding of the mechanisms involved in the platelet\u2013tumor axis represents a paramount aspect for optimizing both current tumor treatment and development of new therapeutic strategies against HCC

Hepatitis C virus intrinsic molecular determinants may contribute to the development of cholestatic hepatitis after liver transplantation

Cholestatic hepatitis C (CHC) is a severe form of hepatitis C virus (HCV) infection recurrence that leads to high graft loss rates early after liver transplantation (LT). To investigate the pathogenic mechanisms of CHC, we analysed HCV quasispecies in CHC patients compared to a control group (mild hepatitis C recurrence) by deep pyrosequencing. At the time of LT, NS5B quasispecies complexity was similar between the two groups but, after LT, it decreased more sharply in CHC patients than in the control group. Interestingly, the major variant before LT propagated efficiently and remained as the dominant sequence after LT in 62% of CHC patients versus 11% of controls (P=0.031). Sequence analysis of the complete nonstructural region in a limited number of patients revealed a potential 12 aa signature specific to the CHC group. These data suggest that intrinsic molecular determinants in the circulating HCV quasispecies may provide a fitness advantage, contributing to the development of CHC

Phylogenetic analysis of an epidemic outbreak of acute hepatitis C in HIV-infected patients by ultra-deep pyrosequencing

Background: The incidence of acute hepatitis C (AHC) among HIV-infected men who have sex with men (MSM) has increased significantly in the last 10 years. Several studies point to a social and sexual network of HIV-positive MSM that extends internationally. Objectives: The aim of our study was to investigate the dynamics of HCV transmission in an outbreak of AHC in HIV-infected MSM in Barcelona by ultra-deep pyrosequencing. Study design: Between 2008 and 2013, 113 cases of AHC in HIV-infected MSM were diagnosed in the Infectious Diseases Unit, Hospital Clínic, Barcelona. Massive sequencing was performed using the Roche 454 GS Junior platform. To define possible transmission networks, maximum likelihood phylogenetic trees were constructed, and levels of genetic diversity within and among patients were compared. Results: Among the 70 cases analyzed, we have identified 16 potential clusters of transmission: 8 for genotype 1a (23 cases involved), 1 for genotype 1b (3 cases) and 7 for genotype 4d (27 cases). Although the initial phylogenetic reconstruction suggested a local transmission cluster of HCV gt4d, our approach based on low genetic differentiation did not corroborate it. Indeed, gt4d strains formed 4 independent groups related to patients from other countries. Conclusions: Frequent clustering of HIV-positive MSM shows that HCV infection has spread through a local network in Barcelona. This outbreak is related to a large international HCV transmission network among MSM. Public health efforts are needed to reduce HCV transmission among this high-risk group

Direct-acting antivirals and hepatocellular carcinoma in chronic hepatitis C: A few lights and many shadows

With the introduction of direct-acting antiviral agents (DAA), the rate of sustained virological response (SVR) in the treatment of hepatitis C virus (HCV) has radically improved to over 95%. Robust scientific evidence supports a beneficial role of SVR after interferon therapy in the progression of cirrhosis, resulting in a decreased incidence of hepatocellular carcinoma (HCC). However, a debate on the impact of DAAs on the development of HCC is ongoing. This review aimed to analyse the scientific literature regarding the risk of HCC in terms of its recurrence and occurrence after the use of DAAs to eradicate HCV infection. Among 11 studies examining HCC occurrence, the de novo incidence rate ranged from 0 to 7.4% (maximum follow-up: 18 mo). Among 18 studies regarding HCC recurrence, the rate ranged from 0 to 54.4% (maximum "not well-defined" followup: 32 mo). This review highlights the major difficulties in interpreting data and reconciling the results of the included studies. These difficulties include heterogeneous cohorts, potential misclassifications of HCC prior to DAA therapy, the absence of an adequate control group, short follow-up times and different kinds of follow-up. Moreover, no clinical feature-based scoring system accounts for the molecular characteristics and pathobiology of the tumours. Nonetheless, this review does not suggest that there is a higher rate of de novo HCC occurrence or recurrence after DAA therapy in patients with previous HCV infection. \ua9 2018 The Author(s). Published by Baishideng Publishing Group Inc. All rights reserved