Recurrent HCV after liver transplantation-mechanisms, assessment and therapy

A Comprehensive Review of Liver Allograft Fibrosis and Steatosis: From Cause to Diagnosis

Despite advances in posttransplant care, long-term outcomes for liver transplant recipients remain unchanged. Approximately 25% of recipients will advance to graft cirrhosis and require retransplantation. Graft fibrosis progresses in the context of de novo or recurrent disease. Recurrent hepatitis C virus infection was previously the most important cause of graft failure but is now curable in the majority of patients. However, with an increasing prevalence of obesity and diabetes and nonalcoholic fatty liver disease as the most rapidly increasing indication for liver transplantation, metabolic dysfunction-associated liver injury is anticipated to become an important cause of graft fibrosis alongside alloimmune hepatitis and alcoholic liver disease. To better understand the landscape of the graft fibrosis literature, we summarize the associated epidemiology, cause, potential mechanisms, diagnosis, and complications. We additionally highlight the need for better noninvasive methods to ameliorate the management of graft fibrosis. Some examples include leveraging the microbiome, genetic, and machine learning methods to address these limitations. Overall, graft fibrosis is routinely seen by transplant clinicians, but it requires a better understanding of its underlying biology and contributors that can help inform diagnostic and therapeutic practices.

Liver Transplantation from a Human Leukocyte Antigen-Matched Sibling Donor: Effectiveness of Direct-Acting Antiviral Therapy against Hepatitis C Virus Infection

Through living-donor liver transplantation (LDLT) from a human leukocyte antigen (HLA)-matched sibling donor, it may be possible to stop the use of immunosuppressants. It is possible that acute antibody-mediated rejection and chronic active antibody-mediated rejection through the positivity of donor-specific anti-HLA antibodies and/or T cell-mediated rejection may affect the prognosis of liver transplantation. The etiologies of liver diseases of the recipient may also affect the post-transplantation course. Herein, we report on the successful re-treatment with direct-acting antiviral (DAA) therapy against hepatitis C virus (HCV) infection in a patient who underwent a LDLT from HLA-matched sibling donor. After liver transplantation for HCV-related liver diseases, it is easy for HCV to re-infect the graft liver under a lack of immunosuppressants. DAA therapy against HCV re-infection immediately after transplantation should be commenced, and it is important to eradicate HCV for better prognosis of the recipients in LDLT for HCV-related liver diseases.

Estimates of prevalence, time-trend, and association of smoking in adults living with HIV, HBV, and HCV (NHANES 1999-2018)

Although the smoking rate of human immunodeficiency virus (HIV), hepatitis B virus (HBV) or hepatitis C virus (HCV) infected people was much higher than that of the general population, smoking cessation interventions have long been ineffective. We aimed to examine the estimates of prevalence, time-trend, and association of smoking among people living with HIV, HBV, or HCV. This cohort was composed of 32,115 individuals from the NHANES database (1999-2018) and they were collected in the US. The time trend analysis of smoking and quitting rates was conducted using different years of survey follow-up and different infected groups. Multivariable logistic regression analysis was used to identify the risk factors related to smoking behavior of these infected people. Compared to non-infected smokers, infected smokers were more likely to be older (aged 30-39, OR = 9.92, CI 6.07-16.21; aged 40-49,OR = 3.51, CI 2.49-4.94), males (1.99, 1.54-2.55), lower education and economic level (1.78, 1.39-2.29; 2.05, 1.59-2.65), unemployed (1.63, 1.21-2.20), suffering depression (1.35, 1.05-1.72), and drug users (7.65, 5.04-11.59). Taken together, our study showed that these complex psychosocial characteristics and unhealthy behavioral factors might be major independent risk factors for increasing smoking rate and decreasing smoking cessation rate among these infected people.

Utility of Mac-2 Binding Protein Glycosylation Isomer to Evaluate Graft Status After Liver Transplantation

Mac-2 binding protein glycosylation isomer (M2BPGi) is a novel liver fibrosis biomarker, but there are few studies on M2BPGi in liver transplantation (LT) recipients. This study aimed to evaluate the utility of M2BPGi measurement in LT recipients. We collected the clinicopathological data of 233 patients who underwent a liver biopsy at Kyoto University Hospital after LT between August 2015 and June 2019. The median values of M2BPGi in patients with METAVIR fibrosis stages F0, F1, F2, and ≥F3 were 0.61, 0.76, 1.16, and 1.47, respectively, whereas those in patients with METAVIR necroinflammatory indexes A0, A1, and ≥A2 were 0.53, 1.145, and 2.24, respectively. Spearman rank correlation test suggested that the necroinflammatory index had a stronger correlation to the M2BPGi value than the fibrosis stage. The area under the receiver operating characteristic curve of M2BPGi to predict ≥A1 was 0.75, which was significantly higher than that of any other liver fibrosis and inflammation marker. Patients with a rejection activity index (RAI) of ≥3 had a higher M2BPGi value than those with RAI ≤ 2 (P = 0.001). Patients with hepatitis C virus viremia had a higher M2BPGi value than sustained virological responders or those with other etiologies. In conclusion, the present study demonstrated that M2BPGi values are more strongly influenced by necroinflammatory activity and revealed M2BPGi, which has been thought to be a so-called fibrosis marker, as a disease activity marker in transplant recipients. M2BPGi measurement may be useful to detect early stage liver inflammation that cannot be detected by routine blood examination of LT recipients.

Hepatitis C Virus Vaccine: Challenges and Prospects

The hepatitis C virus (HCV) causes both acute and chronic infection and continues to be a global problem despite advances in antiviral therapeutics. Current treatments fail to prevent reinfection and remain expensive, limiting their use to developed countries, and the asymptomatic nature of acute infection can result in individuals not receiving treatment and unknowingly spreading HCV. A prophylactic vaccine is therefore needed to control this virus. Thirty years since the discovery of HCV, there have been major gains in understanding the molecular biology and elucidating the immunological mechanisms that underpin spontaneous viral clearance, aiding rational vaccine design. This review discusses the challenges facing HCV vaccine design and the most recent and promising candidates being investigated.

Inferior Outcomes Associated with the Coexistence of Hepatocellular Carcinoma Recurrence and Hepatic Virus Reinfection After Living Donor Liver Transplantation

BACKGROUND

Chronic viral hepatitis remains a major etiology of liver cirrhosis and hepatocellular carcinoma. Liver transplantation has been considered an effective treatment for this condition. This study aims to analyze living donor liver transplantation for patients with hepatocellular carcinoma and its relationship with hepatitis virus status.

METHODS

A retrospective analysis of 268 patients who received living donor liver transplantation for hepatocellular carcinoma was performed. Patients were analyzed according to their serologic status of hepatitis virus; clinicopathologic features, operative parameters, and outcomes were also assessed and compared.

RESULTS

Twenty-three patients (8.6%) had hepatocellular carcinoma recurrence following liver transplantation; the most common pattern of recurrence was systemic spreading (n = 10). Hepatitis B virus relapse was encountered in 41 out of 188 patients (21.8%) with hepatitis B virus-positive, and hepatitis C virus reactivation was noted in 48 (60.8%) patients among 79 hepatitis C virus-positive patients. Incidence of hepatitis C virus reactivation was significantly higher than that of hepatitis B virus relapse (p < 0.0001). Hepatocellular carcinoma recurrence and overall survival were not significantly different in relation to hepatitis virus; however, patients who had hepatocellular carcinoma recurrence combined with hepatitis virus reinfection had the significantly lowest survival rate compared with other groups (p < 0.0001).

CONCLUSION

Living donor liver transplantation based on expanded hepatocellular carcinoma criteria achieved a satisfactory result, but reinfection of hepatic virus remains a great concern particularly in patient with hepatitis C. Moreover, hepatocellular carcinoma recurrence accompanied with reinfection of hepatic virus after liver transplantation is associated with inferior outcomes.

Hepatitis C Virus Infection and Vaccine Development

In the twenty-seven years since the discovery of hepatitis C virus (HCV) the majority of individuals exposed to HCV establish a persistent infection, which is a leading cause of chronic liver disease, cirrhosis and hepatocellular carcinoma. In developed nations, the cure rates of HCV infection could be over 90% with direct-acting antiviral (DAA) regimens, which has made the great progress in global eradication. However, the cost of these treatments is so expensive that the patients in developing nations, where the disease burden is the most severe, could not afford it, which highly restricted its access. Additionally, the largely asymptomatic nature of infection facilitates continued transmission in risk groups due to limited surveillance. Consequently a protective vaccine and likely emergence of drug-resistant viral variants call for further studies of HCV biology. In the current review, the development and the progress of preventive and therapeutic vaccines against the HCV have been reviewed in the context of peptide vaccines, recombinant protein vaccines, HCV-like particle, DNA vaccines and viral vectors expressing HCV genes.

The Role of Monocyte/Macrophage and CXCR3 in Differentiation between Recurrent Hepatitis C and Acute Cellular Rejection Postliver Transplantation

OBJECTIVE

Liver transplantation (LT) is the recommended treatment for patients with advanced liver disease and cirrhosis in all guidelines, mostly as a complication of HCV. The distinction between reinfection of the graft with HCV and acute cellular rejection (ACR) is essential because they are managed differently. Hepatic macrophages, which can either arise from circulating blood-derived monocytes (BDM) or from resident tissue Kupffer cells, are central in the pathogenesis of chronic liver injury. The aim of this work was to evaluate whether the origin of macrophages and the immune mediator CXCR3 could help in differentiating between acute recurrent HCV and ACR after liver transplantation.

METHODS

Twenty-nine cases of recurrent hepatitis C and 26 cases of ACR were included in this study. The expression of CD 68 (macrophage marker), CD11b (BDM marker), and CxCR3 in the postliver transplant biopsy using immunohistochemistry was determined.

RESULTS

CD11b expression highlighting macrophages of BDM origin was in favor of recurrent hepatitis C (P < 0.001) than in ACR (P = 0.44), while CXCR3 expression by hepatocytes was in favor of ACR (P = 0.001).

CONCLUSION

Macrophage infiltrating liver tissue post LT can distinguish between ACR by upregulation of CXCR3 and recurrent hepatitis C by predominant CD11b.

Innate and Adaptive Immune Responses in Chronic HCV Infection

Hepatitis C virus (HCV) remains a public health problem of global importance, even in the era of potent directly-acting antiviral drugs. In this chapter, I discuss immune responses to acute and chronic HCV infection. The outcome of HCV infection is influenced by viral strategies that limit or delay the initiation of innate antiviral responses. This delay may enable HCV to establish widespread infection long before the host mounts effective T and B cell responses. HCV's genetic agility, resulting from its high rate of replication and its error prone replication mechanism, enables it to evade immune recognition. Adaptive immune responses fail to keep up with changing viral epitopes. Neutralizing antibody epitopes may be hidden by decoy structures, glycans, and lipoproteins. T cell responses fail due to changing epitope sequences and due to exhaustion, a phenomenon that may have evolved to limit immune-mediated pathology. Despite these difficulties, innate and adaptive immune mechanisms do impact HCV replication. Immune-mediated clearance of infection is possible, occurring in 20-50% of people who contract the disease. New developments raise hopes for effective immunological interventions to prevent or treat HCV infection.

What are the outcomes of declining a public health service increased risk liver donor for patients on the liver transplant waiting list?

The tragedy of the national opioid epidemic has resulted in a significant increase in the number of opioid-related deaths and accordingly an increase in the number of potential donors designated Public Health Service (PHS) increased risk. Previous studies have demonstrated reluctance to use these PHS organs, and as a result, higher discard rates for these organs have been observed. All patients listed for liver transplantation in the United States from January 2005 to December 2016 were investigated. Patients on the waiting list were divided into 2 groups: those in which a PHS liver was used for transplantation (accepted PHS group) and those in which a PHS liver was declined and transplanted into a recipient lower on the match run (declined PHS group). Intention-to-treat patient survival from the time of PHS offer was significantly higher in the accepted PHS compared with the declined PHS group (P < 0.001). On Cox multivariate regression, declining a PHS donor liver was associated with a hazard ratio of 2.36 (95% confidence interval, 2.23-2.49; P < 0.001). For patients in which a PHS organ offer was declined, 11.6% died or were delisted for being too sick within the subsequent year. Donor liver allografts implanted in the accepted PHS group were of a lower donor risk index (1.28 versus 1.44) compared with the non-PHS organs that patients in the declined PHS group ultimately received if they underwent transplantation. In conclusion, there is a significantly higher survival for patients in which a PHS liver is accepted and used compared with those patients in which a PHS organ is declined. These data will help inform decisions about whether or not to accept a PHS donor liver for both patients and transplant professionals. Liver Transplantation 24 497-504 2018 AASLD.

Noninvasive photoacoustic identification and imaging of gut microbes

Homeostasis of the gut microbiota is indispensable for various physiological functions. Its composition and activity co-develop with the host, and especially associate with human colorectal cancer. However, current composition identification methods are complicated and not timely without spatial distribution information. In this Letter, we explored the photoacoustic imaging (PAI) technique to characterize the composition and quantify the proportions of the gut microbes after optical probe labeling. Our experimental results demonstrated that PAI has the potential to identify different gut bacterial species on the spot.

A cinnamon-derived procyanidin type A compound inhibits hepatitis C virus cell entry

BACKGROUND AND AIMS

Chronic hepatitis C virus (HCV) infection is a major cause of liver disease worldwide. Although direct-acting antivirals can cure the large majority of treated patients, important limitations remain, including treatment failure and high costs precluding access to therapy in resource-limited settings. We report herein the anti-HCV effects of IND02, a procyanidin type A molecule, isolated and characterized from cinnamon.

METHODS AND RESULTS

Using cellculture-derived HCV (HCVcc), HCV pseudoparticles (HCVpp), and subgenomic replicons, we demonstrated that IND02 markedly and dose-dependently inhibited HCV cell entry. Kinetic assays demonstrated that IND02 inhibits HCV entry most likely at a postbinding step. Experiments performed using primary human hepatocytes confirmed inhibition of HCV entry by IND02, demonstrating the functional impact in the most physiological cell-based system for studying HCV-host interactions.

CONCLUSIONS

The natural compound IND02 exhibits potent HCV cell entry inhibition and provides a novel perspective for development of a low-cost antiviral for treatment of HCV infection.

Bowel Thickening in Crohn's Disease: Fibrosis or Inflammation? Diagnostic Ultrasound Imaging Tools

The high frequency of intestinal strictures in patients with Crohn's disease and the different treatment approaches specific for each type of stenosis make the differentiation between fibrotic and inflammatory strictures crucial in management of the disease. However, there is no standardized approach to evaluate and discriminate intestinal strictures, and until now, there was no established cross-sectional imaging modality to detect fibrosis. New techniques, such as contrast-enhanced ultrasound and sonoelastography allow the assessment of vascularization and mechanical properties of stenotic bowel tissue, respectively. These techniques have shown great potential to characterize strictures in Crohn's disease. The aim of this review is to sum up the current knowledge on bowel ultrasound tools to discriminate inflammatory from fibrotic stenosis in Crohn's disease considering the most recent published studies in the field.

Successful Anti-HCV Therapy of a Former Intravenous Drug User with Sofosbuvir and Daclatasvir in a Peritranspant Setting: A Case Report

BACKGROUND Direct-acting antivirals (DAAs) represent a new hallmark in antiviral therapy of hepatitis C virus (HCV). DAAs have been shown to be safe and effective after liver transplantation (LT), but there is little information about their use in peritransplant settings. Former intravenous drug users represent an increasing group seeking HCV treatment. This case report demonstrates the successful peritransplant antiviral treatment of a former intravenous drug user who had been treated in a methadone maintenance program. CASE REPORT The patient was diagnosed with Child B cirrhosis for the first time in 2009. He had a Model for End-stage Liver Disease (MELD) score of 21 and started antiviral therapy with sofosbuvir (SOF) and daclatasvir (DCV) in March 2014. Due to hepatic decompensation, he received a LT in April 2014. Immunosuppression was performed with tacrolimus (TAC) and mycophenolate-mofetil (MMF), and boosted with prednisolone in the initial stage. Four weeks after his LT, the patient presented with an acute renal injury. The patient was discharged one week later after sufficient hydration, discontinuation of non-steroidal anti-phlogistics therapy, and adjustments to his immunosuppressive regimen. At the beginning of his therapy, the number of RNA copies was 13,000 IU/mL. He received 24 weeks of anti-HCV treatment with SOF and DCV; the antiviral treatment was successful and his LT was well tolerated.  CONCLUSIONS Treatment of HCV is feasible in a peritransplant setting. The antiviral regimen we used did not seem to have any relevant interactions with the patient's immunosuppressive regimens. Still, the peritransplant setting is a very demanding environment for anti-HCV therapy, and further studies are needed.

Imaging of intestinal fibrosis: current challenges and future methods

Crohn's disease (CD) activity assessments are dominated by inflammatory changes without discrete measurement of the coexisting fibrotic contribution to total bowel damage. Intestinal fibrosis impacts the development of severe structural complications and the overall natural history of CD. Measuring intestinal fibrosis is challenging and existing methods of disease assessment are unable to reliably distinguish fibrosis from inflammation. Both the immediate clinical need to measure fibrosis for therapeutic decision-making and the near-future need for tools to assess pipeline anti-fibrotic medications highlight the demand for biomarkers of fibrosis in CD. Developing non-invasive technologies exploit changes in intestinal perfusion, mechanical properties, and macromolecular content to provide quantitative markers of fibrosis. In this review of existing and experimental technologies for imaging intestinal fibrosis, we discuss the expanding capabilities of quantitative MR and ultrasound imaging, encouraging developments in non-invasive elastography, and emerging novel methods including photoacoustic imaging.

Review article: treatment as prevention - targeting people who inject drugs as a pathway towards hepatitis C eradication

BACKGROUND

Hepatitis C virus (HCV) is a leading cause of chronic liver disease worldwide. HCV predominates in people who inject drugs; a group in whom anti-viral therapy has previously been withheld on the basis of chaotic lifestyles and associated risks of reinfection. New research has emerged which suggests that by specifically targeting HCV-infected people who inject drugs for treatment, the pool of HCV would deplete, thus reducing overall transmission and eventually leading to HCV eradication.

AIM

To outline the requirements for HCV eradication and review the evidence that this is achievable.

METHODS

Expert review of the literature.

RESULTS

The achievement of HCV eradication using 'treatment as prevention' is supported by numerous epidemiological modelling studies employing a variety of models in several contexts including people who inject drugs, men who have sex with men and prisoners. More recent studies also incorporate the newer, more efficacious direct-acting anti-viral drugs. These drugs have been shown to be safe and effective in people who inject drugs in clinical trials. There is no empirical evidence of the impact of treatment as prevention strategies on population prevalence.

CONCLUSIONS

This review highlights the efforts to control HCV and evaluates the possibilities of achieving eradication of HCV. Currently, the technologies required to achieve HCV eradication exist, but the infrastructure to deliver them is not generally available or of insufficient scale outside of specific areas. Such areas are yet to demonstrate that elimination is possible, but results of studies in these areas are awaited. Such a demonstration would be proof of principle for eradication. Although we are aspiring towards HCV eradication, elimination is the more realistic prospect.

Management of post liver transplantation recurrent hepatitis C infection with directly acting antiviral drugs: a review

Recurrent HCV infection (rHCV) of the liver allograft following transplantation is universal and is associated with poor graft and patient survival in comparison with other indications. Treatment of rHCV infection in the previous era with pegylated interferon and ribavirin was associated with low sustained virological response (SVR) due to poor tolerability, adverse events and graft rejection. Recently, directly acting antiviral drugs (DAA) have been approved for the treatment of hepatitis C infection and a number of clinical trials have been conducted across various centers in the management of rHCV infection of the graft. In this review we discuss about recent studies that have emerged on the use of NS5b polymerase inhibitor, sofosbuvir in combination with second generation protease inhibitor, simeprevir, fixed dose ledipasvir or daclatasvir with or without ribavirin in the treatment of post transplant rHCV infection.

A robust model of natural hepatitis C infection using hepatocyte-like cells derived from human induced pluripotent stem cells as a long-term host

BACKGROUND

Hepatitis C virus (HCV) could induce chronic liver diseases and hepatocellular carcinoma in human. The use of primary human hepatocyte as a viral host is restrained with the scarcity of tissue supply. A culture model restricted to HCV genotype 2a (JFH-1) has been established using Huh7-derived hepatocyte. Other genotypes including the wild-type virus could not propagate in Huh7, Huh7.5 and Huh7.5.1 cells.

METHODS

Functional hepatocyte-like cells (HLCs) were developed from normal human iPS cells as a host for HCV infection. Mature HLCs were identified for selective hepatocyte markers, CYP450s, HCV associated receptors and HCV essential host factors. HLCs were either transfected with JFH-1 HCV RNA or infected with HCV particles derived from patient serum. The enhancing effect of α-tocopherol and the inhibitory effects of INF-α, ribavirin and sofosbuvir to HCV infection were studied. The HCV viral load and HCV RNA were assayed for the infection efficiency.

RESULTS

The fully-developed HLCs expressed phase I, II, and III drug-metabolizing enzymes, HCV associated receptors (claudin-1, occludin, CD81, ApoE, ApoB, LDL-R) and HCV essential host factors (miR-122 and SEC14L2) comparable to the primary human hepatocyte. SEC14L2, an α-tocopherol transfer protein, was expressed in HLCs, but not in Huh7 cell, had been implicated in effective HCVser infection. The HLCs permitted not only the replication of HCV RNA, but also the production of HCV particles (HCVcc) released to the culture media. HLCs drove higher propagation of HCVcc derived from JFH-1 than did the classical host Huh7 cells. HLCs infected with either JFH-1 or wild-type HCV expressed HCV core antigen, NS5A, NS5B, NS3 and HCV negative-stand RNA. HLCs allowed entire HCV life cycle derived from either JFH-1, HCVcc or wild-type HCV (genotype 1a, 1b, 3a, 3b, 6f and 6n). Further increasing the HCVser infection in HLCs was achieved by incubating cell with α-tocopherol. The supernatant from infected HLCs could infect both naïve HLC and Huh7 cell. Treating infected HLC with INF-α and ribavirin decreased HCV RNA in both the cellular fraction and the culture medium. The HLCs reacted to HCVcc or wild-type HCV infection by upregulating TNF-α, IL-28B and IL-29.

CONCLUSIONS

This robust cell culture model for serum-derived HCV using HLCs as host cells provides a remarkable system for investigating HCV life cycle, HCV-associated hepatocellular carcinoma development and the screening for new anti HCV drugs.

Cost-effectiveness of Ombitasvir/Paritaprevir/Ritonavir, Dasabuvir+Ribavirin for US Post-Liver Transplant Recurrent Genotype 1 HCV

BACKGROUND & AIMS

Orthotopic liver transplant patients with recurrent hepatitis C (HCV) historically have had limited treatment options. Ombitasvir/paritaprevir/ritonavir, dasabuvir and ribavirin (3D+R) was approved by the FDA in December 2014 for liver transplant recipients with recurrent genotype 1 HCV, in whom it is effective and well-tolerated.

METHODS

Using a two-phase Markov model, we analysed the cost-effectiveness of 3D+R in liver transplant recipients, the only HCV treatment with FDA approval in this population. As a sensitivity analysis, we also considered the cost-effectiveness of pegylated interferon plus ribavirin, the only other therapy with data from Phase III trials in this population. Patients were given one of three options: 3D+R for 24 weeks, pegylated interferon and ribavirin for 48 weeks (PR48) or no treatment (NT). Patients were then followed through subsequent disease progression until death. Outcome measures analysed were: lifetime risks of liver morbidity and mortality, treatment costs, non-treatment medical expenditures, and quality-adjusted life years.

RESULTS

Treatment with 3D+R was associated with a significantly lower lifetime risk of liver-related morbidity and mortality than treatment with PR48 or NT. 3D+R also was associated with a higher gain in quality-adjusted life years (11.3 compared to 8.25 with NT) and lower discounted overall costs ($423,585 compared to $724,757 with NT).

CONCLUSIONS

The use of 3D+R for liver transplant recipients with recurrent HCV is an outcome-improving and cost-effective regimen for this population with limited treatment options and large unmet need.

Role of liver transplantation in human immunodeficiency virus positive patients

End-stage liver disease (ESLD) is a leading cause of morbidity and mortality amongst human immunodeficiency virus (HIV)-positive individuals. Chronic hepatitis B and hepatitis C virus (HCV) infection, drug-induced hepatotoxicity related to combined anti-retro-viral therapy, alcohol related liver disease and non-alcohol related fatty liver disease appear to be the leading causes. It is therefore, anticipated that more HIV-positive patients with ESLD will present as potential transplant candidates. HIV infection is no longer a contraindication to liver transplantation. Key transplantation outcomes such as rejection and infection rates as well as medium term graft and patient survival match those seen in the non-HIV infected patients in the absence of co-existing HCV infection. HIV disease does not seem to be negatively impacted by transplantation. However, HIV-HCV co-infection transplant outcomes remain suboptimal due to recurrence. In this article, we review the key challenges faced by this patient cohort in the pre- and post-transplant period.

Review on immunosuppression in liver transplantation

The optimal level of immunosuppression in solid organ transplantation, in particular for the liver, is a delicate balance between the benefit of preventing rejection and the adverse side effects of immunosuppression. There is uncertainty about when this level is achieved in any individual recipient. Immunosuppression regimens vary between individual centers and changes with time as new agents and data are available. Presently concerns about the adverse side effects of calcineurin inhibitor, the main class of immunosuppressive agents used in liver transplantation (LT), has led to consideration of the use of antibody induction therapies for patients at higher risk of developing adverse side effects. The longevity of the transplanted organ is potentially improved by better management of rejection episodes and special consideration for tailoring of immunosuppression to the individual with viral hepatitis C, hepatocellular carcinoma or pregnancy. This review provides an overview of the current strategies for post LT immunosuppression and discusses modifications to consider for special patient populations.

Sofosbuvir and simeprevir for treatment of hepatitis C virus infection in liver transplant recipients

Recurrent hepatitis C virus (HCV) infection occurs universally in the allograft in the absence of effective antiviral therapy before liver transplantation (LT). Antiviral therapy with sofosbuvir and simeprevir has proven to be highly effective and well tolerated in the nontransplant setting for treatment of HCV genotype 1 infection; therefore, we sought to evaluate the efficacy and safety of this regimen in LT recipients with recurrent HCV infection. This was a retrospective analysis of a single-center treatment protocol of patients with HCV genotype 1 infection who received a 12-week combination regimen of sofosbuvir and simeprevir. Sixty-one patients (35 with genotype 1a and 26 with genotype 1b) completed treatment with simeprevir and sofosbuvir. Three patients received additional ribavirin. Laboratory data and clinical assessments performed at the baseline, on treatment, at the end of treatment, and 12 weeks after the completion of antiviral therapy [sustained virological response at 12 weeks (SVR12)] were analyzed. The median time after LT was 5.4 years [interquartile range (IQR), 1.9-8.4 years], and tacrolimus was the most commonly used immunosuppressive agent (80.3%). Overall, SVR12 was achieved in 93.4% [95% confidence interval (CI), 84%-97%] of LT recipients treated with 12 weeks of sofosbuvir and simeprevir. When they were analyzed according to the HCV subtype, LT recipients with genotype 1b had a 100% SVR12 rate (95% CI, 87%-100%), whereas SVR12 was 89% (95% CI, 74%-95%) for those with genotype 1a. Advanced fibrosis (METAVIR F3-F4) was associated with diminished antiviral efficacy in LT recipients with genotype 1a [SVR12, 67% (95% CI, 39%-86%); P = 0.01]. Overall, the incidence of adverse events (AEs) was low, and no severe AEs occurred during treatment. In conclusion, treatment with a 12-week regimen of sofosbuvir and simeprevir was well tolerated and resulted in a high SVR12 rate for LT recipients with recurrent HCV genotype 1 infection. Genotype 1a patients with advanced fibrosis of the allograft were more likely to relapse.

Hepatitis C virus: Is it time to say goodbye yet? Perspectives and challenges for the next decade

The majority of individuals exposed to hepatitis C virus (HCV) establish a persistent infection, which is a leading cause of chronic liver disease, cirrhosis and hepatocellular carcinoma. Major progress has been made during the past twenty-five years in understanding the HCV life cycle and immune responses against HCV infection. Increasing evidence indicates that host genetic factors can significantly influence the outcome of HCV infection and the response to interferon alpha-based antiviral therapy. The arrival of highly effective and convenient treatment regimens for patients chronically infected with HCV has improved prospects for the eradication of HCV worldwide. Clinical trials are evaluating the best anti-viral drug combination, treatment doses and duration. The new treatments are better-tolerated and have shown success rates of more than 95%. However, the recent breakthrough in HCV treatment raises new questions and challenges, including the identification of HCV-infected patients and to link them to appropriate health care, the high pricing of HCV drugs, the emergence of drug resistance or naturally occurring polymorphism in HCV sequences which can compromise HCV treatment response. Finally, we still do not have a vaccine against HCV. In this concise review, we will highlight the progress made in understanding HCV infection and therapy. We will focus on the most significant unsolved problems and the key future challenges in the management of HCV infection.

Sofosbuvir and ribavirin before liver re-transplantation for graft failure due to recurrent hepatitis C: a case report

Background

Recurrent hepatitis C virus infection after liver transplantation is associated with reduced graft and patient survival. Re-transplantation for graft failure due to recurrent hepatitis C is controversial and not performed in all centers.

Case presentation

We describe a 54-year-old patient with hepatitis C virus genotype 1b infection and a null response to pegylated interferon-α and ribavirin who developed decompensated graft cirrhosis 6 years after a first liver transplantation. Treatment with sofosbuvir and ribavirin allowed for rapid negativation of serum HCV RNA and was well tolerated despite advanced liver and moderate renal dysfunction. Therapeutic drug monitoring did not reveal any clinically significant drug-drug interactions. Despite virological response, the patient remained severely decompensated and re-transplantation was performed after 46 days of undetectable serum HCV RNA. The patient is doing well 12 months after his second liver transplantation and remains free of hepatitis C virus.

Conclusions

The use of directly acting antivirals may allow for successful liver re-transplantation for recipients who remain decompensated despite virological response and is likely to improve the outcome of liver re-transplantation for end-stage recurrent hepatitis C.