Prevalent immunosuppressive strategies in liver transplantation for hepatitis C: results of a multi-center international survey

The multidisciplinary support in preventing alcohol relapse after liver transplantation: A single-center experience

BACKGROUND AND AIM

Alcoholic liver disease (ALD) represents a frequent indication for liver transplantation (LT). Since 2004, we have adopted a program of multidisciplinary support(MS) to assist patients undergoing LT for ALD. We aimed at analyzing the relapse rate and the risk factors for relapse. The relapse rate was also compared with that of a historical group of patients who underwent transplantation. Their survival rate was also analyzed.

PATIENTS AND METHODS

Consecutive patients with ALD transplanted from 2004 were included. The most important demographic, psychosocial, and clinical characteristics known to be associated with alcohol relapse were recorded.

RESULTS

Sixty-nine patients underwent MS: 8.7% presented alcohol relapse. At multivariate analysis female gender (sHR 9.02, 95% CI 1.71-47.56, P = .009), alcohol withdrawal syndrome (sHR 5.89, 95% CI 1.42-24.46, P = .015) and a shorter time of MS program before LT (sHR 0.928 per month, 95% CI 0.870-0.988, P = .021) were identified as independent risk factors for relapse. The rate of alcohol relapse was significantly lower than that of the historical group who did not undergo MS (sHR 0.21, 95% CI: 0.06-0.68; P = .009).

CONCLUSION

This study shows that a MS program may contribute to alcohol relapse prevention after LT in ALD patients. However, the relevance of this support needs to be confirmed by clinical trials.

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.

Impact of immunosuppression minimization and withdrawal in long-term hepatitis C virus liver transplant recipients

AIM: To investigate the effects of different immunosuppressive regimens and avoidance on fibrosis progression in hepatitis C virus (HCV) liver transplant (LT) recipients.

METHODS: We retrospectively compared the liver biopsies of well-matched HCV LT recipients under calcineurin inhibitors (CNI group, n = 21) and mycophenolate (MMF group, n = 15) monotherapy, with those patients who successfully withdrawn immunosuppression (IS) therapy from at least 3 years (TOL group, n = 10). To perform the well-matched analysis, all HCV transplanted patients from December 1993 were screened. Only those HCV patients who reached the following criteria were considered for the analysis: (1) at least 3 years of post-operative follow-up; (2) patients with normal liver graft function under low dose CNI monotherapy (CNI group); (3) patients with normal liver graft function under antimetabolite (Micophenolate Mofetil or coated mycophenolate sodium) monotherapy (MMF group); and (4) recipients with normal liver function without any IS. We excluded from the analysis recipients who were IS free or under monotherapy for < 36 mo, recipients with cirrhosis or with unstable liver function tests.

RESULTS: Thirty six recipients were enrolled in the study. Demographics, clinical data, time after LT and baseline liver biopsies were comparable in the three groups. After six years of follow-up, there was no worsening of hepatic fibrosis in the MMF group (2.5 ± 1.5 Ishak Units vs 2.9 ± 1.7 Ishak Units, P = 0.5) and TOL group (2.7 ± 10.7 vs 2.5 ± 1.2, P = 0.2). In contrast, a significant increase in the fibrosis score was observed in the CNI group (2.2 ± 1.7 vs 3.9 ± 1.6, P = 0.008). The yearly fibrosis progression rate was significantly worse in the CNI group (0.32 ± 0.35) vs MMF group (0.03 ± 0.31, P = 0.03), and TOL group (-0.02 ± 0.27, P = 0.02). No differences have been reported in grading scores for CNI group (2.79 ± 1.9, P = 0.7), MMF group (3.2 ± 1.5, P = 0.9) and TOL group (3.1 ± 1.4, P = 0.2). Twenty four patients were treated with low dose ribavirin (8 TOL, 7 MMF, 9 CNI). The hepatitis C titers were comparable in the three groups. No episodes of rejection have been reported despite differences of liver function test in the three groups during the observational period.

CONCLUSION: IS withdrawal and MMF monotherapy is safe and seems to be associated with the slowest fibrosis progression in HCV LT recipients.

Recurrent hepatitis C after liver transplant

End stage liver disease from hepatitis C is the most common indication for liver transplantation in many parts of the world accounting for up to 40% of liver transplants. Antiviral therapy either before or after liver transplantation is challenging due to side effects and lower efficacy in patients with cirrhosis and liver transplant recipients, as well as from drug interactions with immunosuppressants. Factors that may affect recurrent hepatitis C include donor age, immunosuppression, IL28B genotype, cytomegalovirus infection, and metabolic syndrome. Older donor age has persistently been shown to have the greatest impact on recurrent hepatitis C. After liver transplantation, distinguishing recurrent hepatitis C from acute cellular rejection may be difficult, although the development of molecular markers may help in making the correct diagnosis. The advent of interferon free regimens with direct acting antiviral agents that include NS3/4A protease inhibitors, NS5B polymerase inhibitors and NS5A inhibitors holds great promise in improving outcomes for liver transplant candidates and recipients.

Strategies to reduce hepatitis C virus recurrence after liver transplantation

Hepatitis C virus (HCV) is a major health problem that leads to chronic hepatitis, cirrhosis and hepatocellular carcinoma, being the most frequent indication for liver transplantation in several countries. Unfortunately, HCV re-infects the liver graft almost invariably following reperfusion, with an accelerated history of recurrence, leading to 10%-30% of patients progressing to cirrhosis within 5 years of transplantation. In this sense, some groups have even advocated for not re-transplanting this patients, as lower patient and graft outcomes have been reported. However, the management of HCV recurrence is being optimized and several strategies to reduce post-transplant recurrence could improve outcomes, decrease the rate of re-transplantation and optimize the use of available grafts. Three moments may be the focus of potential actions in order to decrease the impact of viral recurrence: the pre-transplant moment, the transplant environment and the post-transplant management. In the pre-transplant setting, it is not well established if reducing the pre transplant viral load affects the risk for HCV progression after transplant. Obviously, antiviral treatment can render the patient HCV RNA negative post transplant but the long-term benefit has not yet been fully established to justify the cost and clinical risk. In the transplant moment, factors as donor age, cold ischemia time, graft steatosis and ischemia/reperfusion injury may lead to a higher and more aggressive viral recurrence. After the transplant, discussion about immunosuppression and the moment to start the treatment (prophylactic, pre-emptive or once-confirmed) together with new antiviral drugs are of interest. This review aims to help clinicians have a global overview of post-transplant HCV recurrence and strategies to reduce its impact on our patients.

[Liver transplantation: personalized immunosuppression in patients with hepatitis C virus infection and hepatocellular carcinoma]

Transplantation has become the treatment of choice in end-stage liver disease, with 5-year survival rates of around 68-74% in European and North-American registries (www.unos.org, www.eltr.org, www.ont.es). These results are largely due to the development of powerful immunosuppressive agents, mainly calcineurin inhibitors. However, these immunosuppressive drugs are not free of adverse effects, especially nephrotoxicity. Moreover, two of the most frequent indications for transplantation, cirrhosis due to hepatitis C virus and hepatocellular carcinoma, can recur in the transplanted graft. Whether specific immunosuppression could be less harmful in these conditions is the subject of debate. With the greater use of suboptimal donors and of expanded criteria for liver transplantation in patients with hepatocellular carcinoma, aggressive recurrences can be expected to increase. The present review attempts to elucidate whether there is an immunosuppression strategy that could minimize the risk of aggressive tumoral recurrence or recurrence of hepatitis C.

Immunosuppression and HCV recurrence after liver transplantation

HCV related liver disease is the most common indication for liver transplantation. Recurrence of HCV infection is universal and has a substantial impact on patient and graft survival. Immunosuppression is a major factor responsible for the accelerated recurrence and compressed natural history of recurrent HCV infection. Accumulating experience has provided data to support certain strategies for immunosuppressive regimens. From the available evidence, more severe recurrence results from repeated bolus corticosteroid therapy and anti-lymphocyte antibodies used to treat rejection. Low dose and slow tapering of steroids are better than high dose maintenance and/or rapid tapering. Recent meta-analyses favour steroid-free regimens but these are complicated to interpret as the absence of steroids may simply represent less immunopotency. There is no difference in HCV recurrence between tacrolimus and cyclosporine regimens, but tacrolimus increases graft and patient survival in HCV transplanted patients. There may be a beneficial effect of maintenance azathioprine given for 6 months or longer. There is no conclusive evidence for benefit of mycophenolate and interleukin-2 receptor blockers. Few data are available for mTOR inhibitors. Better evidence is needed to establish the optimal immunosuppressive regimen for HCV recipients and more randomized trials should be performed.

Basiliximab induction and delayed calcineurin inhibitor initiation in liver transplant recipients with renal insufficiency

BACKGROUND

Renal insufficiency (RI) is common after liver transplantation (LT) and may worsen due to calcineurin inhibitor (CNI) use. We compared LT outcomes using basiliximab induction and delayed CNI initiation to controls with a standard CNI regimen in patients with peri-LT RI.

METHODS

All adults transplanted January 2004 to December 2007 with peri-LT RI (hemodialysis or creatinine ≥1.5 within 1 week of LT) were included in a retrospective nonrandomized cohort. Outcomes including 30-day and 1-year patient and graft survival and renal function were compared between basiliximab and control groups.

RESULTS

Two hundred twenty-nine patients (102 basiliximab, 127 controls) were analyzed, mean age 54 years, 72% men, 54% with hepatitis C virus. Mean model for end-stage liver disease (28.2 vs. 20.0; P<0.001) and creatinine (1.9 vs. 1.6; P=0.001) were higher and more patients were on hemodialysis at LT (29% vs. 6%; P<0.001) in the basiliximab group. 30-day patient (99% vs. 97%; P=0.26) and graft survival (98% vs. 95%; P=0.17), 1-year patient (87% vs. 87%; P=0.89) and graft survival (86% vs. 82%; P=0.37), mean creatinine at 1-year (1.5 vs. 1.5 mg/dL; P=0.82), and treated acute rejection (6% vs. 6%; P=0.90) were similar between basiliximab and control groups, respectively. In multivariable logistic regression, basiliximab was not significantly associated with 30-day (odds ratio, 0.10; P=0.11) or 1-year (odds ratio, 0.97; P=0.94) survival, controlling for age, previous LT, model for end-stage liver disease, and hepatitis C virus.

CONCLUSIONS

Basiliximab induction resulted in 30-day and 1-year patient, graft and renal outcomes comparable with a control group receiving standard CNI-based immunosuppression. Antibody induction with delayed CNI should be further studied prospectively.

The impact of sirolimus on hepatitis C recurrence after liver transplantation

BACKGROUND

While some immunosuppression strategies may accelerate hepatitis C virus (HCV) recurrence after liver transplantation (LT), the impact of sirolimus (SRL) is not known.

OBJECTIVE

To assess the risk of biopsy-proven HCV recurrence and patient survival using known and suspected risk factors for HCV recurrence as covariates.

METHODS

A retrospective analysis of 141 consecutive patients, including 88 who received de novo SRL therapy, who had undergone a first LT for HCV cirrhosis was conducted. Known and suspected risk factor covariates including transplant era, donor and recipient age, Model for End-stage Liver Disease score, cold ischemia time, immunosuppressive drugs and steroid treatment rejection rates were used in the assessment.

RESULTS

Overall, 72.3% of the cohort developed biopsy-proven HCV recurrence. The incidence of HCV recurrence was not significantly different for patients treated with SRL (75% versus 69.8%; P=0.5). There was no difference found for time to recurrence, nor did mean activity or fibrosis scores differ at the time of initial recurrence. However, on follow-up using serial biopsies in patients with recurrence, the mean activity and fibrosis scores were significantly lower in the SRL group. Donor age and acute rejection episodes were the only factors affecting the HCV recurrence rate (expB 1.02 [95% CI 1.01 to 1.03]); P=0.03; and expB 2.8 [95% CI 1.8 to 4.3]; P<0.01], respectively). SRL treatment did not alter patient survival rates. Among patients treated with SRL-based immunosuppression, higher drug area under the curve levels were associated with a trend to lower disease activity and fibrosis at diagnosis; however, higher SRL levels were associated with shorter recurrence-free survival (P=0.038).

CONCLUSION

Results of the present analysis suggest that de novo SRL-based immunosuppression can be safely used in patients undergoing LT for HCV-associated liver disease; however, SRL-based immunosuppression did not significantly affect the timing or severity of post-transplant HCV recurrence. HCV recurrence in SRL-treated patients had lower progressive activity and fibrosis levels on serial biopsy.

Recipient-based approach to tailoring immunosuppression in liver transplantation

Improvements in the field of transplant immunosuppression (IS) have led to significant advances in long-term survival of liver transplant recipients. Despite this progress, survival rates vary depending on recipient, donor and/or perioperative factors. Tailoring IS based on recipient factors is of growing interest among health care providers involved in the care of organ transplant recipients. To date there is no consensus document addressing individualized IS therapy for liver transplant recipients. This review will discuss the information available on the effect of the various IS drugs on recipient-based factors such as age, ethnicity, and liver disease etiology.

Pre-emptive antiviral therapy in living donor liver transplantation for hepatitis C: observation based on a single-center experience

Reports of large series in living donor liver transplantation (LDLT) for hepatitis C virus infection (HCV) are scarce. Between 1996 and 2008, 105 LDLTs were performed at the University of Tokyo for HCV. Rapid induction of antiviral treatment with interferon (IFN) and ribavirin (RBV) was attempted per protocol regardless of the clinical presentation of recurrent HCV (pre-emptive treatment approach). Treatment was continued for 12 months after serum HCV-RNA became negative (ETR: end-of-treatment response) and judged as a sustained viral response (SVR) after another 6 months of negative results without treatment. A fixed treatment period was not defined unless an ETR was achieved (no-stopping approach). Flexible dose adjustments were allowed. Ninety-five patients were eligible for pre-emptive therapy. Forty-three (45%) patients experienced an ETR, and 32 (34%) achieved SVR. Nonadherence to full-dose INF and RBV had little impact on the viral response. Evaluation using the Kaplan-Meier method to incorporate the cumulative time-dependent nature of the no-stopping approach estimated SVR rate at 53% by the fifth year. Survival rate at 5 years was 79% for the HCV recipients and did not differ significantly from our non-HCV series. In LDLT for HCV, pre-emptive IFN-RBV-based treatment with the application of no-stopping approach is feasible and effective.

Azathioprine in liver transplantation: a reevaluation of its use and a comparison with mycophenolate mofetil

Calcineurin inhibitors (CNIs) combined with steroids with or without azathioprine (AZA), have been a standard immunosuppression regimen after liver transplantation (LT). Since 2000 many centers have substituted AZA by mycophenolate mofetil (MMF). However, in LT the superiority of MMF over AZA is not clearly demonstrated. Therefore, we questioned the benefit of MMF versus AZA in LT with regard to rejection, renal dysfunction and hepatitis C virus (HCV) recurrence and survival. Using a literature search, relevant randomized controlled trials (RCT) and cohort studies were identified: two RCTs compared MMF to AZA only for acute rejection. Treated rejection was less with MMF in only one RCT (38.5% vs. 47.7%; p = 0.025), with no difference in patient and graft survival. No RCTs compared MMF and AZA in patients with CNI-related chronic renal dysfunction. Among two studies evaluating MMF, with substitution of AZA, one was stopped due to severe rejection. Recurrent HCV was less severe in 5/9 studies with AZA compared with 2/17 using MMF, six of which documented worse recurrence. Published data in LT show little, if any, clinical benefit of MMF versus AZA. RCTs should reevaluate AZA in LT. Evaluation of HCV replication and recurrence will be particularly important as AZA may have advantages over MMF.

Minimization of steroids in liver transplantation

Because of the markedly improved short-term results of liver transplantation (LT) and persistently high number of long-term complications, the attention of transplant physicians should be focused on minimizing immunosuppressive therapy as much as possible. Steroid-based immunosuppression is responsible for a substantial post-LT morbidity and mortality, hence, minimization of its use is of utmost importance to improve the quality of life of the successfully transplanted liver recipient. This literature review shows that LT can be performed safely with steroid-minimal immunosuppression without compromising graft and patient survival. The tendency in clinical practice is to move more and more from steroid withdrawal to steroid avoidance protocols.