Strategies to reduce hepatitis C virus recurrence after liver transplantation

Has the risk of liver re-transplantation improved over the two decades?

BACKGROUND

Despite advancements in liver transplantation (LT) over the past two decades, liver re-transplantation (re-LT) presents challenges. This study aimed to assess improvements in re-LT outcomes and contributing factors.

METHODS

Data from the United Network for Organ Sharing database (2002-2021) were analyzed, with recipients categorized into four-year intervals. Trends in re-LT characteristics and postoperative outcomes were evaluated.

RESULTS

Of 128,462 LT patients, 7254 received re-LT. Graft survival (GS) for re-LT improved (91.3%, 82.1%, and 70.8% at 30 days, 1 year, and 3 years post-LT from 2018 to 2021). However, hazard ratios (HRs) for GS remained elevated compared to marginal donors including donors after circulatory death (DCD), although the difference in HRs decreased in long-term GS. Changes in re-LT causes included a reduction in hepatitis C recurrence and an increase in graft failure post-primary LT involving DCD. Trends identified included recent decreased cold ischemic time (CIT) and increased distance from donor hospital in re-LT group. Meanwhile, DCD cohort exhibited less significant increase in distance and more marked decrease in CIT. The shortest CIT was recorded in urgent re-LT group. The highest Model for End-Stage Liver Disease score was observed in urgent re-LT group, while the lowest was recorded in DCD group. Analysis revealed shorter time interval between previous LT and re-listing, leading to worse outcomes, and varying primary graft failure causes influencing overall survival post-re-LT.

DISCUSSION

While short-term re-LT outcomes improved, challenges persist compared to DCD. Further enhancements are required, with ongoing research focusing on optimizing risk stratification models and allocation systems for better LT outcomes.

Infections after organ transplantation and immune response

Organ transplantation has provided another chance of survival for end-stage organ failure patients. Yet, transplant rejection is still a main challenging factor. Immunosuppressive drugs have been used to avoid rejection and suppress the immune response against allografts. Thus, immunosuppressants increase the risk of infection in immunocompromised organ transplant recipients. The infection risk reflects the relationship between the nature and severity of immunosuppression and infectious diseases. Furthermore, immunosuppressants show an immunological impact on the genetics of innate and adaptive immune responses. This effect usually reactivates the post-transplant infection in the donor and recipient tissues since T-cell activation has a substantial role in allograft rejection. Meanwhile, different infections have been found to activate the T-cells into CD₄⁺ helper T-cell subset and CD₈⁺ cytotoxic T-lymphocyte that affect the infection and the allograft. Therefore, the best management and preventive strategies of immunosuppression, antimicrobial prophylaxis, and intensive medical care are required for successful organ transplantation. This review addresses the activation of immune responses against different infections in immunocompromised individuals after organ transplantation.

Donor and recipient polymorphisms of MAPK signaling pathway genes influence post-transplant liver function in Chinese liver transplant patients taking tacrolimus

Tacrolimus (TAC) is an immunosuppressive drug that is widely used for patients who underwent liver transplantation. In addition to inhibiting the action of calcineurin, TAC also exerts its immunosuppressive effects by interfering with mitogen activated protein kinase (MAPK) pathway. In this study, we investigated the impact of both recipient and donor genetic polymorphisms of MAPK kinase kinase (MAP3K) genes on clinical events in Han Chinese liver transplantation recipients taking TAC. Fifty-seven tag SNPs of 11 genes (MEKK1, MEKK2, MEKK4, MLK1, MLK3, ASK1, TAO1, TAO2, Tpl2, TAK1 and ZAK1) in the MAPK pathway were detected by MALDI-TOF MS assay in 175 TAC-treated liver transplant recipients. The associations of SNPs with incidence of acute rejection, TAC-induced acute nephrotoxicity, and post-transplantation liver and kidney function were explored using Kaplan-Meier survival analysis, Cox-proportional hazard model and linear mixed model, respectively. For the sites significantly associated with clinical events, the dual-luciferase reporter gene system was used to perform preliminary function verification. The results showed that (1) Donor-recipient combinational (D-R) MEKK1 rs62355944 and D-R MLK1 rs8006424 genotypes were significant influence factors of post-transplantation γ-glutamyl transpeptidase (GGT) level (P < 0.0001); (2) D-R MLK1 rs8006424 genotypes were found to significantly affect the alkaline phosphatase (ALP) level after transplantation (P < 0.0001). The results of the dual luciferase reporter gene system demonstrated that the luciferase activity of the pGL3-rs8006424A was significantly higher than that of pGL3-rs8006424G (3.47 ± 0.10 vs 2.97 ± 0.08, P = 0.002). Therefore, MEKK1 rs62355944 and MLK1 rs8006424 might serve as biomarkers to predict post-transplant liver function in liver transplant patients.

Hepatitis C Virus Treatment and Solid Organ Transplantation

Hepatitis C virus (HCV) infection is a common indication for liver transplantation. If the patient's HCV is untreated prior to liver transplant, infection of the allograft is nearly universal and can lead to graft failure. The demand for deceased-donor organ transplantation continues to surpass the available supply of donor organs. Waitlist mortality remains an important concern, and several strategies have been enacted to increase organ supply, such as using high-risk donors, including those who are HCV positive. The development of safe and highly effective HCV therapy with direct-acting antiviral agents has revolutionized the management of liver transplant candidates and transplantrecipients. Moreover, thenewer antiviral therapieshave paved the road for use of HCV-viremic organs, effectively expanding the donor pool and changing the landscape of solid organ transplantation. This article reviews the data on HCV treatment prior to and after organ transplantation.

The road map toward an hepatitis C virus-free transplant population

Antiviral therapy to eradicate hepatitis C virus (HCV) infection improves outcomes in patients undergoing liver transplantation (LT) for advanced chronic HCV with or without hepatocellular carcinoma. Traditionally, antiviral therapy focused on the use of interferon (IFN)-based regimens, with antiviral treatment initiated in the posttransplant period once recurrent HCV disease with fibrosis in the allograft was identified. The use of IFN-based therapy was limited in pretransplant patients with advanced liver disease. Earlier intervention, either before transplantation or early after LT, is now feasible with the advent of second-generation direct-acting antiviral agents (DAAs) with superior tolerability and efficacy to IFN-based therapy. These agents have the potential to reduce the number of patients developing HCV-related complications requiring LT and retransplantation, as well as reducing the demand for donor organs. We discuss the pros and cons of pretransplant, peritransplant, and posttransplant therapy with current DAAs, citing available data from clinical trials and real-world experience.

Elevated Preoperative Serum Bilirubin Improves Reperfusion Injury and Survival Postliver Transplantation

Background

The cytoprotective effects of hemeoxygenase-1 and its product biliverdin/bilirubin are widely acknowledged in experimental transplant medicine. However, its potentially beneficial effect during organ reperfusion is not established.

Methods

In a matched study, we compared markers of reperfusion injury (alanine aminotransferase/aspartate aminotransferase) and transplantation outcome (complication rates, liver function, and survival) between recipient groups with “normal” versus “increased” preoperative bilirubin values. Groups were matched for donor and recipient age, liver disease, year of transplantation, and recipient’s preoperative condition (modified model for end-stage liver disease score excluding bilirubin).

Results

The postoperative transaminase peak was significantly higher when comparing the “normal” to the “increased” bilirubin group (maximum aspartate aminotransferase “normal” 2013 [325-13 210] U/L vs “increased” 1360 [221-15 460] U/L, P = 0.006; maximum alanine aminotransferase “normal” 1151 [82-6595] U/L vs “increased” 820 [66-5382] U/L, P = 0.01). Grafts in the “increased” bilirubin group had faster recovery of graft function with faster decrease in international normalized ratio at days 3 and 7 posttransplantation in the “increased” vs “normal” bilirubin group. Although long-term functional parameters (international normalized ratio and bilirubin posttransplantation) as well as surgical and biliary complication rates were similar in both groups, 1-year survival rates were significantly higher in the group with increased preoperative bilirubin (graft survival, “normal” 86% vs “increased” 97%; P = 0.006).

Conclusions

Increased bilirubin levels of liver graft recipients before transplantation are associated with reduced reperfusion injury and improved survival after transplantation.

Response-Guided Therapy for Hepatitis C Virus Recurrence Based on Early Protocol Biopsy after Liver Transplantation

Hepatitis C virus (HCV) recurrence after liver transplantation (LT) is universal and progressive. Here, we report recent results of response-guided therapy for HCV recurrence based on early protocol biopsy after LT. We reviewed patients who underwent LT for HCV related liver disease between 2010 and 2012. Protocol biopsies were performed at 3, 6, and 12 months after LT in HCV recurrence (positive HCV-RNA). For any degree of fibrosis, ≥ moderate inflammation on histology or HCV hepatitis accompanying with abnormal liver function, we treated with pegylated interferon and ribavirin. We adjusted treatment period according to individual response to treatment. Among 41 HCV related recipients, 25 (61.0%) who underwent protocol biopsies more than once were enrolled in this study. The mean follow-up time was 43.1 (range, 23-55) months after LT. Genotype 1 and 2 showed in 56.0% and 36.0% patients, respectively. Of the 25 patients, 20 (80.0%) started HCV treatment after LT. Rapid or early virological response was observed in 20 (100%) patients. Fifteen (75.0%) patients finished the treatment with end-of-treatment response. Sustained virological response (SVR) was in 11 (55.0%) patients, including 5 (41.7%) of 12 genotype 1 and 6 (75.0%) of 8 non-genotype 1 (P = 0.197). Only rapid or complete early virological response was a significant predictor for HCV treatment response after LT (100% in SVR group vs. 55.6% in non-SVR group, P = 0.026). Overall 3-yr survival rate was 100%. In conclusion, response-guided therapy for HCV recurrence based on early protocol biopsy after LT shows encouraging results.

Liver Transplantation Update: 2014

The first liver transplantation (LT) was performed by Thomas E Starzl five decades ago, and yet it remains the only therapeutic option offering gold standard treatment for end-stage liver disease (ESLD) and acute liver failure (ALF) and certain early-stage liver tumors. Post-liver transplantation survival has also dramatically improved over the last few decades despite increasing donor and recipient age and more frequent use of marginal organs to overcome the organ shortage. Currently, the overall 1 year survival following LT in the United States is reported as 85 to 90%, while the 10 years survival rate is ~50% (http://www.unos.org). The improvements are mainly due to progress in surgical techniques, postoperative intensive care, and the advent of new immunosuppressive agents. There are a number of factors that influence the outcomes prior to transplantation. Since 2002, the model for end-stage liver disease (MELD) score has been considered a predicting variable. It has been used to prioritize patients on the transplant waiting list and is currently the standard method used to assess severity in all etiologies of cirrhosis. Hepatocellular carcinoma (HCC) is the most common standard MELD exception because the MELD does not necessarily reflect the medical urgency of patients with HCC. The criteria for candidates with HCC for receiving LT have evolved over the past decade. Now, patients with HCC who do not meet the traditional Milan (MC) or UCSF criteria for LT often undergo downstaging therapy I an effort to shrink the tumor size. The shortage of donor organs is a universal problem. In some countries, the development of a deceased organ donation program has been prevented due to socioeconomic, cultural, legal and other factors. Due to the shortage of cadaveric donors, several innovative techniques have been developed to expand the organ donor pool, such as split liver grafts, marginal- or extended-criteria donors, live donor liver transplantation (LDLT), and the use of organs donated after cardiac death. Herein, we briefly summarize recent advances in knowledge related to LT. We also report common causes of death after liver transplant, including the recurrence of hepatitis C virus (HCV) and its management, and coronary artery disease (CAD), including the role of the cardiac calcium score in identifying occult CAD.

HOW TO CITE THIS ARTICLE

Dogan S, Gurakar A. Liver Transplantation Update: 2014. Euroasian J Hepato-Gastroenterol 2015;5(2):98-106.

The transplantation of solid organs from HIV-positive donors to HIV-negative recipients: ethical implications

HIV-positive individuals have traditionally been barred from donating organs due to transmission concerns, but this barrier may soon be lifted in the USA in limited settings when recipients are also infected with HIV. Recipients of livers and kidneys with well-controlled HIV infection have been shown to have similar outcomes to those without HIV, erasing ethical concerns about poorly chosen beneficiaries of precious organs. But the question of whether HIV-negative patients should be disallowed from receiving an organ from an HIV-positive donor has not been adequately explored. In this essay, we will discuss the background to this scenario and the ethical implications of its adoption from the perspectives of autonomy, beneficence/non-maleficence and justice.

Management of hepatitis C infection before and after liver transplantation

Chronic hepatitis C (CHC) is the most common indication for liver transplantation (LT). Aggressive treatment of hepatitis C virus (HCV) infection before cirrhosis development or decompensation may reduce LT need and risk of HCV recurrence post-LT. Factors associated with increased HCV risk or severity of recurrence include older age, immunosuppression, HCV genotype 1 and high viral load at LT. HCV recurrence post-LT leads to accelerated liver disease and cirrhosis development with reduced graft and patient survival. Currently, interferon (IFN)-based regimens can be used in dual-agent regimens with ribavirin, in triple-agent antiviral strategies with direct-acting antivirals (e.g., protease inhibitors telaprevir or boceprevir), or before transplant in compensated patients to reduce HCV viral load to prevent or reduce the risk of post-LT recurrence and complications; they cannot be used in patients with decompensated cirrhosis. IFN-based regimens are used in less than half of HCV-infected patients waiting for LT due to extremely low efficacy and poor tolerability. However, antiviral therapy is indicated after LT in patients with histologically confirmed CHC despite tolerability issues. Improvements in side effect management have increased survival in patients achieving therapeutic targets. HCV treatment pre- and post-LT results in significant health care costs especially when lack of efficacy leads to disease worsening, although studies have shown sofosbuvir treatment before LT vs conventional post-LT dual antiviral is cost effective. The suboptimal efficacy and tolerability of IFN-based therapies, plus the significant economic burden, means the need for effective and well tolerated IFN-free anti-HCV therapy for pre- and post-LT remains high.

Tacrolimus-based versus cyclosporine-based immunosuppression in hepatitis C virus-infected patients after liver transplantation: a meta-analysis and systematic review

Background

Most liver transplant recipients receive calcineurin inhibitors (CNIs), especially tacrolimus and cyclosporine, as immunosuppressant agents to prevent rejection. A controversy exists as to whether the outcomes of hepatitis C virus (HCV)-infected liver transplant patients differ based on the CNIs used. This meta-analysis compares the clinical outcomes of tacrolimus-based and cyclosporine-based immunosuppression, especially cases of HCV recurrence in liver transplant patients with end-stage liver disease caused by HCV infection.

Methods

Related articles were identified from the Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, Medline, and Embase. Meta-analyses were performed for the results of homogeneous studies.

Results

Nine randomized or quasi-randomized controlled trials were included. The total effect size of mortality (RR = 0.98, 95% CI: 0.77–1.25, P = 0.87) and graft loss (RR = 1.05, 95% CI: 0.83–1.33, P = 0.67) showed no significant difference between the two groups irrespective of duration of immunosuppressant therapy after liver transplantation. In addition, the HCV recurrence-induced mortality (RR = 1.11, 95% CI: 0.66–1.89, P = 0.69), graft loss (RR = 1.62, 95% CI: 0.64–4.07, P  = 0.31) and retransplantation (RR = 1.40, 95% CI: 0.48–4.09, P = 0.54), as well as available biopsies, confirmed that histological HCV recurrences (RR =  0.92, 95% CI: 0.71–1.19, P = 0.51) were similar.

Conclusion

These results suggested no difference in posttransplant HCV recurrence-induced mortality, graft loss and retransplantation, as well as histological HCV recurrence in patients treated with tacrolimus-based and cyclosporine-based immunosuppresion.

Hepatitis C Recurrence after Orthotopic Liver Transplantation: Mechanisms and Management

Chronic Hepatitis C (HCV) infection is the leading indication for orthotopic liver transplantation and recurrence is nearly universal. Chronic HCV infection is frequently established through evasion of the innate immune system. Priming of adaptive immune responses modulate the severity and rate of fibrosis progression. Those with demonstrable viremia entering the transplant period uniformly suffer recurrence post-transplant. Progression to cirrhosis is accelerated post-transplant secondary to systemic immunosuppression. In addition, a number of factors, including donor, host, and viral characteristics, influence severity and rate of fibrosis progression. Interferon-based therapy, the previous standard of care, in those with advanced cirrhosis or post-transplant has been limited by a number of issues. These include a relative lack of efficacy and poor tolerability with higher incidence of infection and anemia. Recently, approval of direct acting antivirals have ushered in a new era in HCV therapeutics and have applicability in these special populations. Their use immediately prior to or post-transplant is expected to improve both morbidity and mortality.

Genetic variants of innate immune receptors and infections after liver transplantation

Infection is the leading cause of complication after liver transplantation, causing morbidity and mortality in the first months after surgery. Allograft rejection is mediated through adaptive immunological responses, and thus immunosuppressive therapy is necessary after transplantation. In this setting, the presence of genetic variants of innate immunity receptors may increase the risk of post-transplant infection, in comparison with patients carrying wild-type alleles. Numerous studies have investigated the role of genetic variants of innate immune receptors and the risk of complication after liver transplantation, but their results are discordant. Toll-like receptors and mannose-binding lectin are arguably the most important studied molecules; however, many other receptors could increase the risk of infection after transplantation. In this article, we review the published studies analyzing the impact of genetic variants in the innate immune system on the development of infectious complications after liver transplantation.