Sirolimus in liver transplant recipients: a large single-center experience

Side Effects of Immunosuppressant Drugs After Liver Transplant

Liver transplantation (LT) is the standard of care for both end-stage liver failure and hepatocellular carcinoma (HCC). Side effects of the main used immunosuppressive drugs have a noteworthy impact on the long-term outcome of LT recipients. Consequently, to achieve a balance between optimal immunosuppression and minimal side effects is a cornerstone of the post-LT period. Today, there are no validated markers for overimmunosuppression and underimmunosuppression, only a few drugs have therapeutic drug monitoring, and immunosuppression regimens vary from center to center and from country to country. Currently, there are many drugs with different efficacy and safety profiles. Using different agents permits a decrease in the dosage and minimizes the toxicities. A small subset of recipients achieves immunotolerance with the chance to stop immunosuppressive therapy. This article focuses on the side effects of immunosuppressive drugs, which significantly impact long-term outcomes for LT recipients. The primary aim is to highlight the balance between achieving effective immunosuppression and minimizing adverse effects, emphasizing the role of personalized therapeutic strategies. Moreover, this review evaluates the mechanisms of action and specific complications associated with immunosuppressive agents. Finally, special attention is given to strategies for reducing immunosuppressive burdens, improving patient quality of life, and identifying immunotolerant individuals.

Maintenance immunosuppressive therapy in liver transplantation: results from CESIT study, an Italian retrospective cohort study

OBJECTIVES

To investigate the use of maintenance immunosuppressive treatments following liver transplantation and to compare their risk-benefit profiles in clinical practice.

DESIGN

Retrospective multicentrer cohort study.

SETTING

Four Italian regions (Lombardy, Veneto, Lazio, Sardinia).

METHODS

Data were integrated from the national transplant information system and administrative claims data from four Italian regions. All adults who underwent incident liver transplantation between 2009 and 2019 were identified and categorised into two groups: cirrhosis or hepatocellular carcinoma (HCC). The trend of immunosuppressive treatment over years was analysed, and their effectiveness/safety profiles were compared using multivariate Cox models (HR; 95% CI).

MAIN OUTCOME MEASURES

Mortality, transplant reject/graft failure, incidence of severe infections, cancer, diabetes, major adverse cardiovascular events and lipid-modifying agents use.

RESULTS

The study comprised 750 subjects in the cirrhosis cohort and 1159 in the HCC cohort. Over the study years, there was a decline in the use of cyclosporine-CsA, while combination therapy involving tacrolimus with other drugs increased compared with monotherapy. Overall, tacrolimus monotherapy use was slightly over 40% in both groups, followed by tacrolimus+mycophenolate (39.5%-cirrhosis; 30.6%-HCC) and tacrolimus+molecular target of rapamycin inhibitors (mTORi) (8.5%-cirrhosis; 13.3%-HCC). No significant differences emerged in risk-benefit profile of different tacrolimus-based therapies, except for a higher risk of mortality in cirrhosis subjects under tacrolimus monotherapy compared with tacrolimus+mycophenolate (HR: 2.07; 1.17 to 3.65).

CONCLUSIONS

The study highlights a shift over time in postliver transplant therapeutic patterns, favouring the use of tacrolimus in combination with mycophenolate or mTORi, rather than monotherapy. Moreover, a potential association between tacrolimus monotherapy and increased mortality in the cirrhosis cohort was identified. Further research is warranted to investigate these findings more deeply and to optimise treatment strategies for liver transplant recipients.

The Role of mTOR Inhibitors after Liver Transplantation for Hepatocellular Carcinoma

Liver transplantation is a treatment option for nonresectable patients with early-stage HCC, with more significant advantages when Milan criteria are fulfilled. An immunosuppressive regimen is required to reduce the risk of graft rejection after transplantation, and CNIs represent the drugs of choice in this setting. However, their inhibitory effect on T-cell activity accounts for a higher risk of tumour regrowth. mTOR inhibitors (mTORi) have been introduced as an alternative immunosuppressive approach to conventional CNI-based regimens to address both immunosuppression and cancer control. The PI3K-AKT-mTOR signalling pathway regulates protein translation, cell growth, and metabolism, and the pathway is frequently deregulated in human tumours. Several studies have suggested the role of mTORi in reducing HCC progression after LT, accounting for a lower recurrence rate. Furthermore, mTOR immunosuppression controls the renal damage associated with CNI exposure. Conversion to mTOR inhibitors is associated with stabilizing and recovering renal dysfunction, suggesting an essential renoprotective effect. Limitations in this therapeutic approach are related to their negative impact on lipid and glucose metabolism as well as on proteinuria development and wound healing. This review aims to summarize the roles of mTORi in managing patients with HCC undergoing LT. Strategies to overcome common adverse effects are also proposed.

Immunosuppressive regimens for adult liver transplant recipients in real-life practice: consensus recommendations from an Italian Working Group

It is a well-recognized fact that implementing new guidelines in clinical practice may be difficult; therefore the Italian Society for Organ and Tissue Transplantation (SITO) set out to define practical immunosuppression tools for the management of liver transplantation patients. In 2017, an Italian Working Group of liver transplant experts and hepatologists issued a set of consensus statements along with evidence-based recommendations on the use of everolimus after liver transplantation. This article presents the evidence- and consensus-based algorithms developed within the Italian Working Group, which are aimed towards guiding clinicians in the selection of immunosuppressive regimens for the management of adult liver transplant recipients in real-life practice. The liver transplant recipient population, typically managed in clinical practice, was divided into the following categories: (1) standard patients; (2) critically ill patients; (3) patients with a specific etiology; (4) patients with hepatocellular carcinoma; (5) and patients with de novo malignancies. The algorithms are divided into two parts, according to the time from transplantation (0-3 months and > 3 months) and are discussed here along with relevant supporting literature, when available. Ultimately, it is hoped that the evidence- and consensus-based algorithms developed within the Italian Working Group, and presented here, contribute to simplify, personalize, and optimize immunosuppression of liver transplantation recipients in clinical practice.

Sirolimus and MMF are insufficient immunosuppressants for regulation of the proliferation of CD133+EpCAM+ cell populations in HCC cell lines

Studies on effective immunosuppressive strategies for the management of patients undergoing a liver transplantation (LT) due to hepatocellular carcinoma (HCC) are limited. In the present study, immunosuppressive candidates predicted to exhibit beneficial immunosuppressive and tumor-suppressive effects in patients with HCC were assessed using Huh7 and HEP3B HCC cells, which have high proportions of CD133+EpCAM+ cancer stem cell (CSC) populations. The immunosuppressants assessed were sirolimus, tacrolimus, cyclosporine A and mycophenolate mofetil (MMF), and their activities were assessed on CSCs. Sirolimus and MMF reduced the proliferation of Huh7 and HEP3B cells; however, the proportion of CD133+EpCAM+ was notably increased in treated Huh7 cells. Sirolimus treatment alone resulted in G0-G1 cell cycle arrest at all doses in all Huh7 and CD133-EpCAM- populations; however, CD133+EpCAM+ populations showed only slight G1 arrest at higher doses only. In contrast, S-phase arrest was induced at all doses in the Huh7, CD133-EpCAM- and CD133+EpCAM+ populations by MMF. Sirolimus and MMF effectively reduced the proliferation of Huh7 and HEP3B cells, but did not exert a notable effect on the CD133+EpCAM+ cells. Therefore, therapeutic strategies utilizing Sirolimus and MMF should be further studied in vivo for regulation of CSC populations in order to reduce HCC recurrence rates.

Sirolimus and mTOR Inhibitors: A Review of Side Effects and Specific Management in Solid Organ Transplantation

Inhibitors of mechanistic target of rapamycin (mTOR inhibitors) are used as antiproliferative immunosuppressive drugs and have many clinical applications in various drug combinations. Experience in transplantation studies has been gained regarding the side effect profile of these drugs and the potential benefits and limitations compared with other immunosuppressive agents. This article reviews the adverse effects of mTOR inhibitors in solid organ transplantation, with special attention given to mechanisms hypothesized to cause adverse events and their management strategies.

Risk factors for arterial hypertension after liver transplantation

Arterial hypertension represents a common complication of immunosuppressive therapy after liver transplantation (LT). The aim of the study is to evaluate the prevalence and risk factors associated with hypertension after LT. From a cohort of 323 cirrhotic patients who underwent LT from 2008 to 2012, 270 patients were retrospectively evaluated, whereas 53 (16.4%) patients deceased. Hypertension was defined as blood pressure ≥140/90 mm Hg in at least two visits and/or the need for antihypertensive therapy. The prevalence of hypertension was 15% before LT and significantly increased up to 53% after LT (P < .001). Mean follow-up was 43 ± 19 months. In normotensive (NT) subjects at baseline, 35.9% developed sustained hypertension after LT, whereas 15.2% developed transient hypertension within the first month after LT, and then returned NT. The development of sustained hypertension after LT was related to the mammalian target of rapamycin inhibitor treatment (odds ratio [OR], 4.02; 95% confidence interval [CI], 1.26-13.48; P = .02), alcoholic cirrhosis before LT (OR, 3.38; 95% CI, 1.44-8.09; P = .005), and new-onset hepatic steatosis after LT (OR, 2.13; 95% CI, 1.10-4.11; P = .02). Tacrolimus, the etiology and severity of liver disease, and other immunosuppressive regimens were not related to the development of hypertension after LT. In our cohort, the prevalence of arterial hypertension has increased up to 53% after LT, and metabolic comorbidities and immunosuppressive treatment with mammalian target of rapamycin inhibitors are the risk factors for the development of hypertension after LT.

Hepatocellular cancer and recurrence after liver transplantation: what about the impact of immunosuppression?

Liver transplantation (LT) has originally been designed to treat hepatobiliary malignancies. The initial results of LT for hepatocellular cancer (HCC) were, however, dismal this mainly due to the poor patient selection procedure. Better surgical and perioperative care and, especially, the refinement of selection criteria led to a major improvement of results, making HCC nowadays (again!) one of the leading indications for LT. This evolution is clearly shown by the innumerable reports aiming to further extend inclusion criteria for LT in HCC patients. Nonetheless, the vast majority of papers only deals with morphologic (tumour diameter and number) and (only recently) biologic (tumour markers and response to locoregional treatment) parameters to do so. Curiously enough, the role of both the immune competent state of the recipient as well as the impact of both immunosuppression (IS) type and load has been very poorly addressed in this context, even if it has been shown for a long time, based on both basic and clinical research, that they all play a key role in the outcome of any oncologic treatment and in the development of de novo as well as recurrent tumours. This chapter aims to give, after a short introductive note about the currently used inclusion criteria of HCC patients for LT and about the role of IS in carcinogenesis, a comprehensive overview of the actual literature related to the impact of different immunosuppressive drugs and schemes on outcome of LT in HCC recipients. Unfortunately, up to now solid conclusions cannot be drawn due to the lack of high-level evidence studies caused by the heterogeneity of the studied patient cohorts and the lack of prospectively designed and randomized studies. Based on long-term personal experience with immunosuppressive handling in LT some proposals for further clinical research and practice are put forward. The strategy of curtailing and minimising IS should be explored in the growing field of transplant oncology taking thereby into account the immunological privilege of the liver allograft. These strategies will become more and more compelling when further extending the indications in which adjuvant chemotherapy will probably become an inherent part of the therapeutic scheme of HCC liver recipients.

Sirolimus and Metformin Synergistically Inhibits Colon Cancer In Vitro and In Vivo

We estimated the effect of various immunosuppressants (ISs) and metformin (M) to provide theoretical background of optimal therapeutic strategy for de novo colon cancer after liver transplantation (LT). Three colon cancer cell lines (HT29, SW620, and HCT116) were used in in vitro studies. HT29 was also used in BALB/c-nude mice animal models. Following groups were used in both in vitro and in vivo studies: sirolimus (S), tacrolimus (T), cyclosporin A (CsA), M, metformin/sirolimus (Met/S), metformin/tacrolimus (Met/T), and metformin/cyclosporin A (Met/CsA). 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed and western blot analyses were performed for mTOR pathway proteins, apoptosis proteins, and epithelial-mesenchymal-transition (EMT) proteins. Tumor volume was measured for 4 weeks after inoculation. MTT-assay revealed significant cell viability inhibition in all 3 colon cancer cell lines in groups of S, M, and Met/S. Of note, group Met/S showed synergistic effect compare to M or S group. Western blot analysis showed significant low levels of all investigated proteins in groups of S and Met/S in both in vitro and in vivo experiment. Tumor growth was significantly inhibited only in the Met/S group. Combination of Met and S showed the most potent inhibition in all colon cancer cell lines. This finding might have application for de novo colon cancer.

Use of Everolimus in Liver Transplantation: Recommendations From a Working Group

Immunosuppression after liver transplantation (LT) is presently based on use of calcineurin inhibitors (CNI), although they are associated with an increased incidence of renal dysfunction, cardiovascular complications, and de novo and recurrent malignancies. Over the past decade, mammalian target of rapamycin inhibitors have received considerable attention as immunosuppressants because they are associated with a more favorable renal profile versus CNI, as well as antiproliferative activity in clinical studies. Comprehensive guidelines on use of everolimus (EVR) in LT are still lacking. In Italy, a project, named Everolimus: the road to long-term functioning, was initiated to collect the experience on EVR after LT with the aim of providing guidance for transplant clinicians. Herein, recommendations by this national consensus group, based on Delphi methodology, are presented. Consensus was reached on 20 of the 23 statements proposed, and their level of evidence, grade of recommendation, and percent of agreement are reported. Statements are grouped into 4 areas: (A) renal function; (B) time of EVR introduction, CNI reduction and elimination, and risk for graft rejection; (C) antiproliferative effects of EVR; and (D) management of EVR-related adverse events. The high level of consensus shows that there is good agreement on the routine use of EVR in predefined clinical scenarios, especially in light of posttransplant nephrotoxicity and other adverse events associated with long-term administration of CNIs.

The authors summarize the recommendations reached by an Italian National Consensus group using the Delphi methodology on the use of everolimus in liver transplantation, particularly its role in renal function, antiproliferative effects, adverse events, timing of introduction, and rejection risk.

Neurologic complications of transplantation

Major neurologic morbidity, such as seizures and encephalopathy, complicates 20-30% of organ and stem cell transplantation procedures. The majority of these disorders occur in the early posttransplant period, but recipients remain at risk for opportunistic infections and other nervous system disorders for many years. These long-term risks may be increasing as acute survival increases, and a greater number of "sicker" patients are exposed to long-term immunosuppression. Drug neurotoxicity accounts for a significant proportion of complications, with posterior reversible leukoencephalopathy syndrome, primarily associated with calcineurin inhibitors (i.e., cyclosporine and tacrolimus), being prominent as a cause of seizures and neurologic deficits. A thorough evaluation of any patient who develops neurologic symptoms after transplantation is mandatory, since reversible and treatable conditions could be found, and important prognostic information can be obtained.

New-onset diabetes mellitus after pediatric liver transplantation

In the first five yr after liver transplant, approximately one in 10 pediatric recipients will develop NODAT. Factors associated with higher risk for NODAT have been difficult to identify due to lack of uniformity in reporting and data collection. Limited studies have reported higher risk in those who are at an older age at transplant, those with high-risk ethnic backgrounds, and in those with particular underlying conditions, such as CF and primary sclerosing cholangitis. Immunosuppressive medications, including tacrolimus, cyclosporine A, GC, and sirolimus, have been implicated as contributing to NODAT, to varying degrees. Identifying those at highest risk, appropriately screening, and diagnosing NODAT is critical to initiating timely treatment and avoiding potential complications. In the pediatric population, treatment is limited primarily to insulin, with some consideration for metformin. Children with NODAT should be monitored carefully for complications of DM, including microalbuminuria, hypertension, hyperlipidemia, and retinopathy.

[National S3 guidelines on hepatocellular carcinoma]

CLINICAL/METHODICAL ISSUE

Evidence-based therapeutic and diagnostic algorithm for hepatocellular carcinoma.

STANDARD RADIOLOGICAL METHODS

Ultrasound, computed tomography, magnetic resonance imaging, image-guided percutaneous biopsy, percutaneous thermal ablation and transarterial chemoembolization.

METHODICAL INNOVATIONS

Diagnostic and therapy of hepatocellular carcinoma according to the official German interdisciplinary guidelines.

PERFORMANCE

The formulation of the German S3 guidelines on diagnosis and therapy of hepatocellular carcinoma was performed under special consideration of quality indicators and standardized quality improvement methods.

ACHIEVEMENTS

In 2013 the German S3 guidelines on diagnosis and therapy of hepatocellular carcinoma were published and clinically implemented as part of the nationwide guideline program in oncology of the Deutsche Krebsgesellschaft (German Cancer Society).

PRACTICAL RECOMMENDATIONS

The German S3 guidelines on diagnosis and therapy of hepatocellular carcinoma have to be considered as the national gold standard with the goal of optimization of patient care.

Hypothermic Oxygenated Perfusion (HOPE) downregulates the immune response in a rat model of liver transplantation

OBJECTIVE

To evaluate the impact of a novel oxygenated perfusion approach on rejection after orthotopic liver transplantation (OLT).

BACKGROUND

Hypothermic oxygenated perfusion (HOPE) was designed to prevent graft failure after OLT. One of the mechanisms is downregulation of Kupffer cells (in situ macrophages). We, therefore, designed experiments to test the effects of HOPE on the immune response in an allogeneic rodent model of nonarterialized OLT.

METHODS

Livers from Lewis rats were transplanted into Brown Norway rats to induce liver rejection in untreated recipients within 4 weeks. Next, Brown Norway recipients were treated with tacrolimus (1 mg/kg), whereas in a third group, liver grafts from Lewis rats underwent HOPE or deoxygenated machine perfusion for 1 hour before implantation, but recipients received no immunosuppression. In a last step, low-dose tacrolimus treatment (0.3 mg/kg) was assessed with and without HOPE.

RESULTS

Allogeneic OLT without immunosuppression led to death within 3 weeks after nonarterialized OLT due to severe acute rejection. Full-dose tacrolimus prevented rejection, whereas low-dose tacrolimus led to graft fibrosis within 4 weeks. HOPE treatment without immunosuppression also protected from lethal rejection. The combination of low-dose tacrolimus and 1-hour HOPE resulted in 100% survival within 4 weeks without any signs of rejection.

CONCLUSIONS

We demonstrate that allograft treatment by HOPE not only protects against preservation injury but also impressively downregulates the immune system, blunting the alloimmune response. Therefore, HOPE may offer many beneficial effects, not only to rescue marginal grafts but also by preventing rejection and the need for immunosuppression.

Mammalian target of rapamycin inhibitors are associated with lower rates of hepatocellular carcinoma recurrence after liver transplantation: a systematic review

Calcineurin inhibitors (CNIs) have been associated in a dose-dependent fashion with an increased risk of post-transplant hepatocellular carcinoma (HCC) recurrence. The mammalian target of rapamycin inhibitors (mTORi) (sirolimus/everolimus) might represent an alternative immunosuppressive regimen with antineoplastic effect. In the present systematic review, the association between mTORi and HCC recurrence after liver transplantation (LT) was evaluated and compared against that of CNIs-treated patients. In total, 3666 HCC liver transplant recipients from 42 studies met the inclusion criteria. Patients under CNIs developed HCC recurrence significantly more frequently, compared with patients under mTORi (448/3227 or 13.8% vs. 35/439 or 8%, P < 0.001), although patients treated with CNIs had a higher proportion of HCC within Milan criteria (74% vs. 69%) and lower rates of microvascular invasion, compared with mTORi-treated patients (22% vs. 44%) (P < 0.05). Patients on everolimus had significantly lower recurrence rates of HCC, compared with those on sirolimus or CNIs (4.1% vs. 10.5% vs. 13.8%, respectively, P < 0.05), but everolimus-treated recipients had shorter follow-up period (13 vs. 30 vs. 43.2 months, respectively) and more frequently been transplanted for HCC within Milan criteria (84% vs. 60.5% vs. 74%, respectively, P < 0.05). Our findings favor the use of mTORi instead of CNIs to control HCC recurrence after LT, but comparative studies with longer follow-up are needed for final conclusions.

Tailored long-term immunosuppressive regimen for adult liver transplant recipients with hepatocellular carcinoma

Backgrounds/Aims

There are few guidelines for tailored immunosuppressive regimens for liver transplantation (LT) recipients with hepatocellular carcinoma (HCC). To establish long-term immunosuppressive regimens suitable for Korean adult LT recipients, we analyzed those that were currently in use at a single high-volume institution.

Methods

This cross-sectional study comprises three parts including review of the immunosuppressive regimens used to manage 2,147 adult LT outpatients, review of LT recipients who were diagnosed of HCC at LT, and review of LT recipients who suffered from HCC recurrence.

Results

In 1,000 adult LT recipients who were living more than 5 years with no adverse events, 916 received a calcineurin inhibitor (CNI)-based therapy (CNI only in 520; CNI with mycophenolate mofetil [MMF] in 396) and 84 were receiving an MMF-based therapy (MMF only in 45; MMF with minimal CNI in 39). Tacrolimus was preferred over cyclosporine for both monotherapy and combination therapy along the passage of posttransplant period. There was no difference in selection of immunosuppressants, target blood concentration, and rate of combination therapy between LT recipients with and without HCC, except for the first 1 year. Sirolimus-based regimens were applied in 21 patients who showed HCC recurrence. Sorafenib was often used after conversion to sirolimus.

Conclusions

Tailored immunosuppressive regimen covering the long-term posttransplant period should be established after consideration of individualized patient profiles including HCC.

The Role of mTOR Inhibitors in Liver Transplantation: Reviewing the Evidence

Despite the success of liver transplantation, long-term complications remain, including de novo malignancies, metabolic syndrome, and the recurrence of hepatitis C virus (HCV) and hepatocellular carcinoma (HCC). The current mainstay of treatment, calcineurin inhibitors (CNIs), can also worsen posttransplant renal dysfunction, neurotoxicity, and diabetes. Clearly there is a need for better immunosuppressive agents that maintain similar rates of efficacy and renal function whilst minimizing adverse effects. The mammalian target of rapamycin (mTOR) inhibitors with a mechanism of action that is different from other immunosuppressive agents has the potential to address some of these issues. In this review we surveyed the literature for reports of the use of mTOR inhibitors in adult liver transplantation with respect to renal function, efficacy, safety, neurological symptoms, de novo tumors, and the recurrence of HCC and HCV. The results of our review indicate that mTOR inhibitors are associated with efficacy comparable to CNIs while having benefits on renal function in liver transplantation. We also consider newer dosing schedules that may limit side effects. Finally, we discuss evidence that mTOR inhibitors may have benefits in the oncology setting and in relation to HCV-related allograft fibrosis, metabolic syndrome, and neurotoxicity.

Evidence for rapamycin toxicity in pancreatic β-cells and a review of the underlying molecular mechanisms

Rapamycin is used frequently in both transplantation and oncology. Although historically thought to have little diabetogenic effect, there is growing evidence of β-cell toxicity. This Review draws evidence for rapamycin toxicity from clinical studies of islet and renal transplantation, and of rapamycin as an anticancer agent, as well as from experimental studies. Together, these studies provide evidence that rapamycin has significant detrimental effects on β-cell function and survival and peripheral insulin resistance. The mechanism of action of rapamycin is via inhibition of mammalian target of rapamycin (mTOR). This Review describes the complex mTOR signaling pathways, which control vital cellular functions including mRNA translation, cell proliferation, cell growth, differentiation, angiogenesis, and apoptosis, and examines molecular mechanisms for rapamycin toxicity in β-cells. These mechanisms include reductions in β-cell size, mass, proliferation and insulin secretion alongside increases in apoptosis, autophagy, and peripheral insulin resistance. These data bring into question the use of rapamycin as an immunosuppressant in islet transplantation and as a second-line agent in other transplant recipients developing new-onset diabetes after transplantation with calcineurin inhibitors. It also highlights the importance of close monitoring of blood glucose levels in patients taking rapamycin as an anticancer treatment, particularly those with preexisting glucose intolerance.

Anti-CD25 monoclonal antibody replacement therapy for chronic kidney disease in liver transplant recipients

BACKGROUND

Chronic kidney disease (CKD) is a frequent complication after liver transplantation (LT) and is associated with increased mortality. Strategies to reduce calcineurin inhibitor (CNI) dose or conversion to either mycophenolate mofetil and/or rapamycin resulted in variable results and side-effect profiles.

METHODS

We evaluated the effectiveness of CNI conversion to long-term anti-CD25 monoclonal antibody (mAb)-based immunosuppression in 15 adult LT patients with CKD at 7.6±4 years posttransplant (intervention group). Three patients had been previously switched to rapamycin, and 12 patients were on CNI. The control group included 15 LT patients on CNI with stable renal function over a similar posttransplant follow-up period.

RESULTS

Anti-CD25 mAb were given over a period of 26±15 months (range, 2-51 months) and were well tolerated. The slope of calculated creatinine clearance was -0.66 mL/min/month over 6 months before conversion and -0.05 mL/min/month after conversion to anti-CD25 mAb (P=0.16 and P=0.86 vs. controls). Three acute rejection episodes occurred in the intervention group. Acute rejection was reversible in two patients. However, one patient died of chronic rejection 1 year after having been switched to tacrolimus. Anti-CD25 mAb were replaced with either CNI or rapamycin in six patients (acute rejection [n=2], progression to end-stage renal disease [n=2], poor venous status [n=1], increased liver enzymes [n=1]).

CONCLUSION

The use of long-term anti-CD25 mAb therapy as a replacement to CNI and rapamycin-based immunosuppression may be feasible. It is crucial that rejection surveillance is intensified. A randomized controlled trial is required to confirm the benefits of this strategy.

Meta-analysis: recurrence and survival following the use of sirolimus in liver transplantation for hepatocellular carcinoma

BACKGROUND

The use of sirolimus (SRL)-based immunosuppression protocols have been reported to reduce recurrence rates following liver transplantation (LT) for hepatocellular carcinoma (HCC), although this is still a matter for debate.

AIM

To undertake a systematic review and meta-analysis of available literature on the usage of SRL as an immunosuppressive agent following LT for HCC, with a view to comparing cancer outcomes with the commonly used calcineurin inhibitors (CNIs).

METHODS

Systematic review and meta-analysis carried out in line with the Meta-analysis Of Observational Studies in Epidemiology (MOOSE) guidelines. Primary outcomes of interest were tumour recurrence rate and recurrence-free survival (RFS). Secondary outcomes were recurrence-related mortality and overall survival (OS).

RESULTS

In all, 5 studies met the inclusion criteria (n = 474). The recurrence rate was lower in SRL group (4.9-12.9%) in comparison with CNIs (17.3-38.7%). The 1-, 3- and 5-year RFS was 93-96%, 82-86% and 79-80% for SRL group, which was much better in comparison with the CNIs 70-78%, 64-65% and 54-60% respectively. Similarly, 1-, 3- and 5-year OS was much better for SRL group (94-95%, 85% and 80%) in comparison with CNIs (79-83%, 66% and 59-62%) respectively. Meta-analysis demonstrated lower recurrence (OR = 0.30, 95% CI = 0.16-0.55, P < 0.001), lower recurrence-related mortality (OR = 0.29, 95% CI = 0.12-0.70, P = 0.005) and lower overall mortality (OR = 0.35, 95% CI = 0.20-0.61, P < 0.001) for SRL group.

CONCLUSION

The review showed lower recurrence rate, longer recurrence-free survival and overall survival and lower recurrence-related mortality in sirolimus-treated patients in comparison with the calcineurin inhibitor-treated patients following liver transplantation for hepatocellular carcinoma.

Current and Future Treatment Strategies for Patients with Advanced Hepatocellular Carcinoma: Role of mTOR Inhibition

Hepatocellular carcinoma (HCC) is a common cancer that has the third highest cancer-related mortality rate worldwide. Although potentially curable by transplantation if detected early, the majority of cases are diagnosed at an advanced stage of disease for which limited treatment options are available. The only proven systemic therapy for advanced HCC is sorafenib, a multi-kinase inhibitor that has demonstrated modest efficacy and reasonable tolerability in patients with advanced HCC. Five years after the approval of sorafenib, no other agent has been proven to be beneficial in the first- or second-line setting in advanced HCC. While molecular studies have highlighted various potential targets in HCC, the mammalian target of rapamycin (mTOR) has emerged as an exciting target for cancer therapy including HCC. Laboratory data have linked the phosphatidylinositol 3-kinase/AKT/mTOR axis to various oncogenic processes, including survival and angiogenesis. Historically, mTOR inhibitors have been used for their immunosuppressive properties, but more recently they have been approved as anticancer agents. Retrospective HCC studies suggest that the inclusion of mTOR inhibition as part of an immunosuppressant regimen after transplantation may reduce HCC recurrence compared with other immunosuppressive agents such as calcineurin inhibitors. More recently, single-arm, phase I/II studies have shown that mTOR inhibitors also have activity as monotherapy in cases of recurrent HCC or de novo advanced HCC. This article will review the rationale for targeting the mTOR pathway in HCC, and the currently available clinical data supporting its development for HCC.

Central pontine myelinolysis: a case report and clinical-pathological review

An 11-yr-old child presented with acute mental status changes and spastic quadriplegia after orthotopic liver transplantation. Magnetic resonance (MR) imaging findings were consistent with central pontine and EPM. Initial immunosuppression included tacrolimus, mycophenolate mofetil, and corticosteroids. Given that neurotoxicity is a well-established side effect of CNI, the patient was converted to rapamycin and subsequently experienced significant neurologic recovery. The temporal resolution of the patient's symptoms suggests that prompt recognition of central pontine and EPM and conversion from tacrolimus to rapamycin during the early post-operative course may have therapeutic benefits for patients undergoing pediatric transplant with CNI-related neurotoxicity.

Medical management of the liver transplant recipient

Long-term survival of liver transplant recipients has become the rule rather than the exception. As a result, the medical complications of long-term survival, including atherosclerotic cardiovascular disease, metabolic bone disease, and de novo malignancy, have accounted for an increasing proportion of late morbidity and mortality. Risk factors for these complications begin before transplant and are potentially modifiable but are exacerbated by the requirement for immunosuppressive medications after transplantation. Surveillance and early intervention programs administered by transplant hepatologists and other medical subspecialists may improve long-term outcomes in liver transplant recipients by ameliorating risk factors for atherosclerosis, bone fractures, and cancer.

The metabolic and toxicological considerations for mTOR inhibitors in the treatment of hepatocarcinoma

INTRODUCTION

Hepatocellular carcinoma (HCC) is a major health problem worldwide. Several molecular pathways involved in HCC growth and progression have recently been identified. Rapamycin analogs are able to inhibit one of the most active oncogenic molecular pathways in HCC cells: the mammalian target of rapamycin (mTOR) pathway.

AREAS COVERED

In this review, the authors analyze the principal molecular features of the mTOR pathway and the use of rapamycin analogs in the treatment of hepatocarcinoma. The article also looks at the reoccurrence of HCC following liver transplantation as well as after the treatment of de novo neoplasms. Finally, the authors discuss the advantage of using a combined HCC pharmacological therapy to obtain a synergistic effect on tumor mass.

EXPERT OPINION

Among the available options for the treatment of advanced-stage HCC, mTOR pathway inhibitors show great promise. Once these agents have their safety and efficacy confirmed, in the treatment of liver disease, their use should be considered in patients affected by HCC. This should especially be the case for those who have had liver transplants or suffered with de novo tumors. Moreover, the authors believe that mTOR inhibitors could be used in a combined pharmacological approach to improve HCC molecular-targeted therapy by producing a multiple-level block of tumor intracellular signaling.

Calcineurin-inhibitor minimization in liver transplant patients with calcineurin-inhibitor-related renal dysfunction: a meta-analysis

Background

Introduction of calcineurin-inhibitor (CNI) has made transplantation a miracle in the past century. However, the side effects of long-term use of CNI turn out to be one of the major challenges in the current century. Among these, renal dysfunction attracts more and more attention. Herein, we undertook a meta-analysis to evaluate the efficacy and safety of calcineurin-inhibitor (CNI) minimization protocols in liver transplant recipients with CNI-related renal dysfunction.

Methods

We included randomized trials with no year and language restriction. All data were analyzed using random effect model by Review Manager 5.0. The primary endpoints were glomerular filtration rate (GFR), serum creatinine level (sCr) and creatinine clearance rate (CrCl), and the secondary endpoints were acute rejection episodes, incidence of infection and patient survival at the end of follow-up.

Results

GFR was significantly improved in CNI minimization group than in routine CNI regimen group (Z = 5.45, P<0.00001; I² = 0%). Likely, sCr level was significantly lower in the CNI minimization group (Z = 2.84, P = 0.005; I² = 39%). However, CrCl was not significantly higher in the CNI minimization group (Z = 1.59, P = 0.11; I² = 0%). Both acute rejection episodes and patient survival were comparable between two groups (rejection: Z = 0.01, P = 0.99; I² = 0%; survival: Z = 0.28, P = 0.78; I² = 0%, respectively). However, current CNI minimization protocols may be related to a higher incidence of infections (Z = 3.06, P = 0.002; I² = 0%).

Conclusion

CNI minimization can preserve or even improve renal function in liver transplant patients with renal impairment, while sharing similar short term acute rejection rate and patient survival with routine CNI regimen.

Influence of immunosuppressive drugs on the recurrence of hepatocellular carcinoma after liver transplantation: a gap between basic science and clinical evidence

Effects of immunosuppressive drug on tumor development in transplantation are understudied. Tumors are especially concerning when liver transplantation recipients have a pretransplant hepatocellular carcinoma (HCC). Because immunosuppressive drugs likely influence HCC recurrence, with mammalian target of rapamycin inhibitors showing antineoplastic properties especially experimentally, we sought for practical medical guidance from published clinical studies. Although the current literature review revealed 14 studies regarding immunosuppression in this context, suggesting antitumor effects for mammalian target of rapamycin inhibitors, the quality of evidence is low. Therefore, randomized controlled trials investigating effects of immunosuppression on HCC recurrence in liver transplantation are lacking, exposing a gap between basic science knowledge and clinical evidence.

Evolving concepts in the selection of immunosuppression regimen for liver transplant recipients

The introduction of calcineurin inhibitor (CNI) based immunosuppression has revolutionized the field of liver transplantation by dramatically reducing the incidence of acute cellular rejection and prolonging patient and allograft survival. However, the introduction of CNIs has also come at the price of increased patient morbidity, particularly with regard to the well-known nephrotoxic effects of the medications. In an effort to minimize the adverse effects, immunosuppression regimen have evolved to include the use of various induction agents and purine synthesis inhibitors to limit the dose of CNI necessary to achieve low acute cellular rejection rates. Careful assessments of risks and benefits are needed as these newer agents have their own side effect profiles. In addition, the impact of newer immunosuppression regimen on hepatitis C (HCV) recurrence has not been completely elucidated. This review will provide an overview of the most common immunosuppression regimen used in liver transplantation and discuss their impact on acute cellular rejection, patient and allograft survival, and HCV recurrence.

Causes of sirolimus discontinuation in 97 liver transplant recipients

INTRODUCTION

Sirolimus is a potent immunosuppressant with a mechanism of action different from calcineurin inhibitors (CNIs). It has increasing importance for liver transplant (OLT) patients, in particular if when there is decreased renal function. We evaluated the efficacy and the causes for discontinuation of sirolimus-based immunosuppression among OLT recipients.

OBJECTIVE

We retrospectively analyzed 97 liver transplanted patients who were prescribed sirolimus as the principal immunosuppressant. Of these, 61 patients discontinued treatment. Herein we have reported the causes, the timing, and the effects of sirolimus discontinuation.

RESULTS

The overall patient survival at 3 years follow-up was 89%. Hepatotoxicity and blood disorders were the most frequent, severe reported side effects. Acute cellular rejection episodes appeared in seven patients and was relieved in 1 to 2 weeks after the sirolimus administration. In 10 patients, the cholestasis associated with chronic rejection was sharply reduced after the introduction of sirolimus. No increase in vascular thrombosis and/or poor wound healing were reported.

CONCLUSION

Sirolimus given alone or in combination with CNIs appears to be an effective primary immunosuppressant regimen for OLT patients. However, in the late postoperative period (>3 months) the drug is associated with a relatively high rate of side effects.