Switching to sirolimus-based immune suppression after liver transplantation is safe and effective: a single-center experience

Assessment of Donor Liver Pathology Predicts Survival After Liver Transplantation: A Retrospective Cohort Study

BACKGROUND

The aims of this study were to investigate the pathologic manifestation of pretransplant biopsy and to provide an accurate assessment method for liver graft of China Donation after Citizen's Death (CDCD).

METHODS

A retrospective analysis was performed based on clinical and biopsy data of 96 CDCD liver transplantations completed between January 2012 and December 2017. The pretransplant pathologic sections were semiquantitatively scored according to Banff Schema recommendations on liver allograft pathology. Graft overall survival (OS) and early allograft dysfunction (EAD) rates were observed.

RESULTS

The histologic analysis of the 96 CDCD liver graft biopsy specimens was summarized, including portal area neutrophilic infiltrate, macrovesicular steatosis, microvesicular steatosis, and hepatocellular swelling. Among these pathologic characteristics, only portal area neutrophilic infiltrate ≥20% was an independent risk factor for graft survival, although it has limited effect on the recipient's short-term prognosis.

CONCLUSIONS

We found that portal area neutrophilic infiltrate ≥20% was an independent risk factors for long-term graft survival. According to this criterion, we can identify liver transplant recipients at risk for poor prognosis and make timely interventions.

Trends of rapamycin in survival benefits of liver transplantation for hepatocellular carcinoma

The proportion of liver transplantation (LT) for hepatocellular carcinoma (HCC) has kept on increasing over the past years and account for 20%-40% of all LT. Post-transplant HCC recurrence is considered the most important factor affecting the long-term survival of patients. The use of different types of immunosuppressive agents after LT is closely associated with an increased risk for HCC recurrence. The most commonly used conventional immunosuppressive drugs include the calcineurin inhibitors tacrolimus (FK506) and mammalian target of rapamycin inhibitor rapamycin (RAPA). Compared with tacrolimus, RAPA may carry an advantage in survival benefit because of its anti-tumor effects. However, no sufficient evidence to date has proven that RAPA could increase long-term recurrence-free survival and its anti-tumor mechanism of combined therapy remains incompletely clear. In this review, we will focus on recent advances in clinical application experience and basic research results of RAPA in patients undergoing LT for HCC to further guide the clinical practice.

Cardiovascular and metabolic disease in the liver transplant recipient

Liver transplantation has led to great improvements in long-term survival in patients with decompensated liver disease and hepatocellular carcinoma. Cardiovascular disease is the leading cause of non-graft-related deaths and has increased prevalence in liver allograft recipients. This is partly secondary to higher post-transplant rates of metabolic risk factors-notably obesity, hypertension, dyslipidemia, and diabetes mellitus, which comprise metabolic syndrome. Post-transplantation metabolic syndrome is expected to be a growing factor in morbidity and mortality as transplant candidates trend older, the rates of metabolic risk factors in the general population increase, non-alcoholic steatohepatitis grows disproportionally as an indication for transplantation, and post-transplantation survival lengthens. This review discusses the incidence and contributory factors for post-transplant increases in metabolic disease, as well as the burden of cardiovascular disease in the liver allograft recipient. Patients with pre-transplant diabetes or obesity are at particularly high risk for post-transplant metabolic syndrome, and would likely benefit from closer surveillance and more aggressive medical management of risk factors. In metabolic disease resistant to initial medical therapies, tailoring of immunosuppressive regimens may further assist in minimizing long-term cardiovascular disease, although this must be done with caution to avoid worsening the risk of graft failure.

Metabolic and Renal Effects of Mammalian Target of Rapamycin Inhibitors Treatment After Liver Transplantation: Real-Life Single-Center Experience

BACKGROUND

Mammalian target of rapamycin (mTOR) inhibitors following liver transplantation (LT) are used to minimize calcineurin inhibitor (CNI)-related nephrotoxicity. Data about metabolic effects of mTOR inhibitors are still limited.

AIM

This study aims to determine the renal and metabolic effects of different mTOR inhibitor-based protocols in real-life LT patients.

METHODS

This is a retrospective cohort study of patients treated with mTOR inhibitors after LT. Demographics, treatment protocols, glomerular filtration rate (GFR), and metabolic parameters were collected over a period of 4 years. Initiation of blood pressure (BP), diabetes mellitus, and lipid medications was also noted.

RESULTS

Fifty-two LT recipients received mTOR inhibitors. GFR improved significantly (by 1.96 mL/min/year), with greater improvement in patients with baseline renal dysfunction (+13.3 mL/min vs +4.5 mL/min at 3 years). Conversion to an mTOR inhibitor during the first post-transplant year resulted in a more durable improvement in GFR (for 4 years vs only 1 year for later conversion).No significant weight gain or new-onset diabetes mellitus was observed. However, there was some increase in total cholesterol (+7 mg/dL) and blood pressure (+2 mm Hg during the third year and +8 mm Hg in the fourth years), followed by initiation of lipid-lowering and BP medications in 25% and 13% of patients, respectively.

CONCLUSIONS

Treatment with an mTOR inhibitor following LT resulted in improved kidney functions without significant negative metabolic effects such as weight gain or new-onset diabetes mellitus. This makes mTOR inhibitors a valuable immunosuppressive option in the face of the growing incidence of nonalcoholic steatohepatitis as a leading cause for LT.

Proteinuria and baseline renal function predict mortality and renal outcomes after sirolimus therapy in liver transplantation recipients

Background

Chronic kidney disease is a significant complication after liver transplantation (LT), but the role of pre-existing renal insufficiency and proteinuria remains unclear among LT recipients receiving sirolimus.

Methods

We assessed the effects of proteinuria and baseline renal function on long-term renal and survival outcomes among 576 LT recipients who received SRL in a medical center between 2005 and 2014. Renal outcomes were the incidences of >50% reduction in their baseline estimated glomerular filtration rate and end stage kidney disease requiring renal replacement therapy. Proteinuria was identified using morning dipstick results (≥30 mg/dL) at baseline and within the first year after the initiation of SRL therapy. A Kaplan-Meier analysis was performed to estimate time to event. Factors associated with the outcomes were determined using the Cox proportional hazards model with a significance level set at P <0.05.

Results

During the study period, renal function deteriorated in 135 (25.3%) patients and 68 (11.8%) patients died. Persistent and new onset proteinuria contributed to a high rate of mortality and the deterioration of renal function (both log-rank tests, P <0.0001). After adjustments, new onset proteinuria within the first year after the initiation of SRL therapy increased the risk of deteriorating renal function, regardless of baseline estimated glomerular filtration rate. Moreover, pre-existing (hazard ratio = 1.91; P <0.001) and new onset diabetes (hazard ratio = 2.34; P <0.0001) were significantly associated with new onset proteinuria among SRL users.

Conclusions

These findings support the effective monitoring and early management of the predictable risks for proteinuria among new SRL users in order to delay the progression of renal disease.

Role of mTOR inhibitors for the control of viral infection in solid organ transplant recipients

Appropriate post-transplant immunosuppressive regimens that avoid acute rejection, while reducing risk of viral reactivation, have been sought, but remain a chimera. Recent evidence suggesting potential regulatory and antiviral effects of mammalian target of rapamycin inhibitors (mTORi) is of great interest. Although the concept of an immunosuppressive drug with antiviral properties is not new, little effort has been made to put the evidence together to assess the management of immunosuppressive therapy in the presence of a viral infection. This review was developed to gather the evidence on antiviral activity of the mTORi against the viruses that most commonly reactivate in adult solid organ recipients: cytomegalovirus (CMV), polyomavirus, Epstein-Barr virus (EBV), human herpesvirus 8 (HHV8), and hepatitis C virus (HCV). A rapid review methodology and evaluation of quality and consistency of evidence based on the GRADE system was used. The existing literature was variable in nature, although indicating a potential advantage of mTORi in CMV, polyomavirus, and HHV8 infection, and a most doubtful relation with EBV and HCV infection. Several recommendations about the management of these infections are presented that can change certain current patterns of immunosuppression and help to improve the prognosis of the direct and indirect effects of viral infection in solid organ recipients.

Sirolimus Use in Liver Transplant Recipients With Hepatocellular Carcinoma: A Randomized, Multicenter, Open-Label Phase 3 Trial

We investigated whether sirolimus-based immunosuppression improves outcomes in liver transplantation (LTx) candidates with hepatocellular carcinoma (HCC).

In a large prospective randomized open-label international trial, liver transplant recipients for HCC were randomized to receive non-mTOR-inhibitor-based-treatment or mTOR-inhibitor-based-treatment. Results indicate overall sirolimus does not improve long-term recurrence-free survival beyond 5 years while a benefit was seen in low-risk patients. Supplemental digital content is available in the text.

Trends in the use of maintenance immunosuppressive drugs among liver transplant recipients in Taiwan: a nationwide population-based study

PURPOSE

During the past two decades, many novel immunosuppressive drugs have been approved for transplant recipients. Trends in the use of maintenance immunosuppressants after liver transplantation in Asia are unclear. Thus, we aimed to analyze the prescription trends in maintenance immunosuppressive drugs among liver transplant recipients in Taiwan and compare the results with the trends reported from western countries.

METHODS

We conducted a retrospective nationwide population-based study utilizing the National Health Insurance Research Database (NHIRD) to analyze the prescribing patterns of immunosuppressants used in Taiwanese liver transplant recipients from 2000 to 2009.

RESULTS

A total of 1686 liver transplant patients and their prescriptions of immunosuppressants were analyzed. The 5-year survival rate of liver transplant recipients was 79.6%. In 2009, the major immunosuppressive therapy among liver transplant recipients was a dual-drug regimen with tacrolimus and mycophenolic acid (57.3%). Among the calcineurin inhibitors (CNI), the use of cyclosporine decreased from 58.9% to 12.5%, while the use of tacrolimus notably increased from 23.3% to 77.5%. The use of azathioprine decreased from 21.3% to 0.4%, while the use of mycophenolic acid increased from 56.1% to 76.5%. Among the mammalian target of rapamycin (mTOR) inhibitors, sirolimus was approved in 2002, and its use increased to 8.7% in 2009. In the first 3 months after liver transplantation, a total of 17 different regimens were used in 2009, compared with seven regimens in 2000.

CONCLUSIONS

Although the CNI-based combination obviously remains the major regimen, our results reveal a trend toward individualized immunosuppressive regimens among Taiwanese liver transplant recipients. Copyright © 2016 John Wiley & Sons, Ltd.

Analysis of ischemia/reperfusion injury in time-zero biopsies predicts liver allograft outcomes

Ischemia/reperfusion injury (IRI) that develops after liver implantation may prejudice long-term graft survival, but it remains poorly understood. Here we correlate the severity of IRIs that were determined by histological grading of time-zero biopsies sampled after graft revascularization with patient and graft outcomes. Time-zero biopsies of 476 liver transplants performed at our center between 2000 and 2010 were graded as follows: nil (10.5%), mild (58.8%), moderate (26.1%), and severe (4.6%). Severe IRI was associated with donor age, donation after circulatory death, prolonged cold ischemia time, and liver steatosis, but it was also associated with increased rates of primary nonfunction (9.1%) and retransplantation within 90 days (22.7%). Longer term outcomes in the severe IRI group were also poor, with 1-year graft and patient survival rates of only 55% and 68%, respectively (cf. 90% and 93% for the remainder). Severe IRI on the time-zero biopsy was, in a multivariate analysis, an independent determinant of 1-year graft survival and was a better predictor of 1-year graft loss than liver steatosis, early graft dysfunction syndrome, and high first-week alanine aminotransferase with a positive predictive value of 45%. Time-zero biopsies predict adverse clinical outcomes after liver transplantation, and severe IRI upon biopsy signals the likely need for early retransplantation.

A retrospective 15-year review: survival advantage after switching to sirolimus in hepatitis C virus infected liver graft recipients

BACKGROUND

The use of sirolimus-based immune suppression in liver transplantation, particularly in hepatitis C virus (HCV)-infected recipients, remains contentious. There is some evidence that sirolimus retards hepatic fibrosis, is renal sparing and may be of benefit in preventing hepatocellular carcinoma (HCC) recurrence. Sirolimus has not been adopted by many transplant centres because of persistent concerns regarding an increased risk of hepatic artery thrombosis, graft loss and death with de novo sirolimus.

AIM

To review the impact of switching to sirolimus monotherapy in HCV-infected liver recipients with respect to survival, graft loss and hepatic fibrosis.

METHODS

A retrospective review of 190 patients from a single centre undergoing first liver transplantation for HCV over 15 years. 113 patients were switched from calcineurin inhibitor (CNI)-based therapy to low-dose sirolimus monotherapy at a median of 15 months after transplantation for HCV-related fibrosis (72%), renal impairment (14%) or high-risk HCC (5%).

RESULTS

Patients switched to sirolimus had improved survival (P < 0.001) and slower progression to cirrhosis (P = 0.001). In patients with HCC (n = 91), sirolimus duration rather than strategy was an independent predictor of survival (P = 0.001) and extended time to HCC recurrence (33 vs. 16 months). Patients switched for renal dysfunction showed improvement in serum creatinine (140-108 μmol/L, P = 0.001). Those remaining on CNI-therapy were more likely to develop post-transplant diabetes (P = 0.03).

CONCLUSION

These data suggest selective switching to low-dose sirolimus monotherapy in HCV-positive liver recipients improves clinical outcome.

Sirolimus reduces the risk of significant hepatic fibrosis after liver transplantation for hepatitis C virus: a single-center experience

INTRODUCTION

Hepatitis C virus (HCV) recurrence following orthotopic liver transplantation is an expected outcome in all patients transplanted for a primary diagnosis of HCV. HCV recurrence has been shown to be associated with graft fibrosis and graft loss. Recent studies suggest that sirolimus (SRL) therapy may slow or inhibit hepatic fibrosis following liver transplant in patients positive for HCV at the time of transplant.

METHODS

Among 313 patients who underwent orthotopic liver transplantation for HCV between 2000 and 2009, 251 qualified for inclusion in the study. Per protocol liver biopsies were performed on all patients at 1 year following liver transplantation and/or at the time of a clinical diagnosis of HCV recurrence. Biopsies were scored for fibrosis using the Batts-Ludwig staging system (0-4); significant fibrosis was defined as fibrosis ≥ stage 2.

RESULTS

Overall, there was no difference in overall survival or graft loss in the SRL compared with the control group. Multivariate analysis revealed SRL therapy to be associated with decreased odds of significant hepatic fibrosis at year 1 postoperatively and over the study duration.

CONCLUSIONS

This retrospective, single-center study showed sirolimus-based immunosuppression to be associated with a lower risk of significant graft fibrosis, both at year 1 and throughout the study period, following liver transplantation in HCV-infected recipients.

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.

Living-donor liver transplantation and hepatitis C

Hepatitis-C-virus- (HCV-) related end-stage cirrhosis is the primary indication for liver transplantation in many countries. Unfortunately, however, HCV is not eliminated by transplantation and graft reinfection is universal, resulting in fibrosis, cirrhosis, and finally graft decompression. In areas with low deceased-donor organ availability like Japan, living-donor liver transplantation (LDLT) is similarly indicated for HCV cirrhosis as deceased-donor liver transplantation (DDLT) in Western countries and accepted as an established treatment for HCV-cirrhosis, and the results are equivalent to those of DDLT. To prevent graft failure due to recurrent hepatitis C, antiviral treatment with pegylated-interferon and ribavirin is currently considered the most promising regimen with a sustained viral response rate of around 30% to 35%, although the survival benefit of this regimen remains to be investigated. In contrast to DDLT, many Japanese LDLT centers have reported modified treatment regimens as best efforts to secure first graft, such as aggressive preemptive antiviral treatment, escalation of dosages, and elongation of treatment duration.

Lipid metabolism and oxidative stress in children after liver transplantation treated with sirolimus

Lipid disturbances are one of the most frequent side effects of SRL; however, clinical consequences are not known. The aim of the study was to evaluate the risk of AS in children after LTx treated with SRL. In 17 children with median age 13.2 yr (1.9-17.9) who received SRL on average for 4.1 yr (s.d. ± 2.9) we measured and compared with age-matched healthy control group (n = 45) lipid parameters and markers of AS: ADMA, oxyLDL, GSH, GPx, TC, TG, HDL cholesterol, LDL cholesterol, VLDL cholesterol, ApoAI, ApoB, ApoE, lipoprotein (a) (Lp(a)). We found no major differences in cholesterol, cholesterol in lipoprotein fractions and TG concentrations between patients receiving SRL and the control group. ApoE was markedly increased in the study group (19.1 g/L [±1.8]) when compared to controls (9.8 [±3.9]). ApoA1 was decreased in the study group: 1.30 g/L (±0.2) vs. 1.45 (±0.25), p = 0.04. ApoB and Lpa concentrations were similar in both groups. There were differences in oxidative stress markers: GSH 743 (±66.2) mol/mL vs. 780 (±48.2), p = 0.02 and GPx 32.8 (±5.5) U/gHb vs. 34.3(±2.6), p = 0.01. Markers of AS: ADMA did not differ between groups and oxidized LDLc was significantly lower in SRL group: 190 mU/mL (±113) vs. 237 (±107) in control, p < 0.05. SRL does not significantly disturb lipid metabolism and oxidative status in children after LTx.

Targeting the PI3K/AKT/mTOR signaling axis in children with hematologic malignancies

The phosphatidylinositiol 3-kinase (PI3K), AKT, mammalian target of rapamycin (mTOR) signaling pathway (PI3K/AKT/mTOR) is frequently dysregulated in disorders of cell growth and survival, including a number of pediatric hematologic malignancies. The pathway can be abnormally activated in childhood acute lymphoblastic leukemia (ALL), acute myelogenous leukemia (AML), and chronic myelogenous leukemia (CML), as well as in some pediatric lymphomas and lymphoproliferative disorders. Most commonly, this abnormal activation occurs as a consequence of constitutive activation of AKT, providing a compelling rationale to target this pathway in many of these conditions. A variety of agents, beginning with the rapamycin analogue (rapalog) sirolimus, have been used successfully to target this pathway in a number of pediatric hematologic malignancies. Rapalogs demonstrate significant preclinical activity against ALL, which has led to a number of clinical trials. Moreover, rapalogs can synergize with a number of conventional cytotoxic agents and overcome pathways of chemotherapeutic resistance for drugs commonly used in ALL treatment, including methotrexate and corticosteroids. Based on preclinical data, rapalogs are also being studied in AML, CML, and non-Hodgkin's lymphoma. Recently, significant progress has been made using rapalogs to treat pre-malignant lymphoproliferative disorders, including the autoimmune lymphoproliferative syndrome (ALPS); complete remissions in children with otherwise therapy-resistant disease have been seen. Rapalogs only block one component of the pathway (mTORC1), and newer agents are under preclinical and clinical development that can target different and often multiple protein kinases in the PI3K/AKT/mTOR pathway. Most of these agents have been tolerated in early-phase clinical trials. A number of PI3K inhibitors are under investigation. Of note, most of these also target other protein kinases. Newer agents are under development that target both mTORC1 and mTORC2, mTORC1 and PI3K, and the triad of PI3K, mTORC1, and mTORC2. Preclinical data suggest these dual- and multi-kinase inhibitors are more potent than rapalogs against many of the aforementioned hematologic malignancies. Two classes of AKT inhibitors are under development, the alkyl-lysophospholipids (APLs) and small molecule AKT inhibitors. Both classes have agents currently in clinical trials. A number of drugs are in development that target other components of the pathway, including eukaryotic translation initiation factor (eIF) 4E (eIF4E) and phosphoinositide-dependent protein kinase 1 (PDK1). Finally, a number of other key signaling pathways interact with PI3K/AKT/mTOR, including Notch, MNK, Syk, MAPK, and aurora kinase. These alternative pathways are being targeted alone and in combination with PI3K/AKT/mTOR inhibitors with promising preclinical results in pediatric hematologic malignancies. This review provides a comprehensive overview of the abnormalities in the PI3K/AKT/mTOR signaling pathway in pediatric hematologic malignancies, the agents that are used to target this pathway, and the results of preclinical and clinical trials, using those agents in childhood hematologic cancers.

Proteinuria following sirolimus conversion is associated with deterioration of kidney function in liver transplant recipients

BACKGROUND

The role of sirolimus (SRL) conversion in the preservation of kidney function in liver transplant (LT) recipients with calcineurin inhibitor (CNI) nephrotoxicity is unclear.

METHODS

Data on 102 LT recipients with deteriorating kidney function after CNI exposure who were later converted to SRL were retrospectively reviewed. Kidney function was assessed using serum creatinine and estimated glomerular filtration rate (eGFR) at time of conversion and serially thereafter. The primary endpoint was stabilization or improvement of kidney function as assessed by eGFR at last recorded follow-up compared with eGFR at the time of conversion.

RESULT

After a median (interquartile range) of 3.1 (1.6-4.5) years of follow-up, serum creatinine decreased from 1.9 ± 0.8 to 1.8 ± 0.7 mg/dL (P=0.25) and eGFR increased from 40.8 ± 16.7 to 44.3 ± 20.0 mL/min (P=0.03). During the same time period, 24-hr urinary protein excretion increased from median (interquartile range) of 72 (0-155) to 382 (169-999) mg/day (P=0.0001). Sixty-five (64%) patients achieved the primary endpoint and 37 (36%) experienced deterioration in kidney function. Independent predictors of deterioration of kidney function after SRL conversion were development of proteinuria ≥ 1000 mg/day (odds ratio [OR]: 3.3, confidence interval [CI]: 1.1-9.5 P=0.03), post-LT diabetes (OR: 4.2, CI: 1.6-11.1, P=0.004), and higher eGFR at time of conversion (OR: 1.6, CI: 1.2-2.2, P=0.003).

CONCLUSION

Improvement or stabilization of kidney function occurred in the majority of LT recipients converted to SRL for CNI nephrotoxicity. Proteinuria ≥ 1000 mg/day, post-LT diabetes, and higher baseline eGFR were independent predictors of kidney function loss after SRL conversion.

Long-term outcome of conversion to sirolimus monotherapy after liver transplant

OBJECTIVES

This study sought to assess the long-term efficacy and safety of conversion from a calcineurin inhibitor-based immunosuppressive regimen to sirolimus monotherapy in liver transplant recipients with renal dysfunction.

MATERIALS AND METHODS

Twenty-five liver transplant recipients with calcineurin inhibitor-based immunosuppression were included in this single-center, prospective study. Indications were renal dysfunction, avoidance of tumor recurrence, combination renal dysfunction and avoidance of tumor recurrence, and calcineurin inhibitor-related adverse effects.

RESULTS

Mean interval between liver transplant and initiation of sirolimus monotherapy was 51.7 months. The mean follow-up was 75.6 months. The mean ± SD sirolimus whole-blood trough level was 9.0 ± 2.8 ng/mL after 6 months and 6.0 ± 1.8 ng/mL after 18 months. No rejection episodes occurred. There was an improvement of the mean creatinine level: 156.1 ± 54.9 μmol/L before conversion versus 129.1 ± 34.7 μmol/L approximately 3 years after conversion (P < .05). The glomerular filtration rate, measured by technetium Tc-99m-diethylenetriamine penta-acetic aerosol scintigraphy, improved from 27.4 ± 6.8 mL/min/1.73 m(2) before conversion to 43.3 ± 6.3 mL/min/1.73 m(2) at final follow-up. Proteinuria increased after conversion to sirolimus after 6 months (P < .05) and at last follow-up. The systolic blood pressure decreased from 151.5 ± 20.2 to 132.1 ± 19.4 mm Hg, and the diastolic from 89.7 ± 11.2 to 82.1 ± 9.1 mm Hg at last follow-up. Serum cholesterol and serum triglyceride levels were nearly unchanged. However, 50% of the patients were treated with lipid-lowering agents. Four patients had sirolimus-induced adverse effects (thrombocytopenia, gingival hyperplasia, oral ulceration).

CONCLUSIONS

Conversion from calcineurin inhibitors to sirolimus monotherapy after liver transplant results in stabilization of renal function in 75% to 85% of cases and of blood pressure, without increased risk of rejection. The spectrum of adverse effects is low.

Spanish society of liver transplantation (SETH) consensus recommendations on hepatitis C virus and liver transplantation

In November 2010, the Spanish Society of Liver Transplantation (Sociedad Española de Trasplante Hepático, SETH) held a consensus conference. One of the topics of debate was liver transplantation in patients with hepatitis C. This document reviews (i) the natural history of post-transplant hepatitis C, (ii) factors associated with post-transplant prognosis in patients with hepatitis C, (iii) the role of immunosuppression in the evolution of recurrent hepatitis C and response to antiviral therapy, (iv) antiviral therapy, both before and after transplantation, (v) follow-up of patients with recurrent hepatitis C and (vi) the role of retransplantation.

Comparison of liver transplantation outcomes from adult split liver and circulatory death donors

BACKGROUND

Adult whole-organ donation after circulatory death (DCD) and 'split' extended right lobe donation after brain death (ERL-DBD) liver transplants are considered marginal, but direct comparison of outcomes has rarely been performed. Such a comparison may rationalize the use of DCD livers, which varies widely between UK centres.

METHODS

Outcomes for adult ERL-DBD livers and 'controlled' DCD liver transplantations performed at the Cambridge Transplant Centre between January 2004 and December 2010 were compared retrospectively.

RESULTS

None of the 32 patients in the DCD cohort suffered early graft failure, compared with five of 17 in the ERL-DBD cohort. Reasons for graft failure were hepatic artery thrombosis (3), progressive cholestasis (1) and small-for-size syndrome (1). Early allograft dysfunction occurred in a further five patients in each group. In the DCD group, ischaemic cholangiopathy developed in six patients, resulting in graft failure within the first year in two; the others remained stable. The incidence of biliary anastomotic complications was similar in both groups. Kaplan-Meier survival analysis confirmed superior graft survival in the DCD liver group (93 per cent at 3 years versus 71 per cent in the ERL-DBD cohort; P = 0·047), comparable to that of contemporaneous whole DBD liver transplants (93 per cent at 3 years). Patient survival was similar in all groups.

CONCLUSION

Graft outcomes of DCD liver transplants were better than those of ERL-DBD liver transplants. Redefining DCD liver criteria and refining donor-recipient selection for ERL-DBD transplants should be further explored.

Liver transplantation and hepatitis C

Hepatitis-C-virus- (HCV-) related end-stage cirrhosis is the primary indication for liver transplantation in many countries. Unfortunately, however, HCV is not eliminated by transplantation and graft reinfection is universal, resulting in fibrosis, cirrhosis, and finally graft decompensation. The use of poor quality organs, particularly from older donors, has a highly negative impact on the severity of recurrence and patient/graft survival. Although immunosuppressive regimens have a considerable impact on the outcome, the optimal regimen after liver transplantation for HCV-infected patients remains unclear. Disease progression monitoring with protocol biopsy and new noninvasive methods is essential for predicting patient/graft outcome and starting antiviral treatment with the appropriate timing. Antiviral treatment with pegylated interferon and ribavirin is currently considered the most promising regimen with a sustained viral response rate of around 30% to 35%, although the survival benefit of this regimen remains to be investigated. Living-donor liver transplantation is now widely accepted as an established treatment for HCV cirrhosis and the results are equivalent to those of deceased donor liver transplantation.

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.

Neuroprotective, immunosuppressant and antineoplastic properties of mTOR inhibitors: current and emerging therapeutic options

The acronym mTOR defines a family of serine-threonine protein kinase called mammalian target of rapamycin. The major role of these kinases in the cell is to merge extracellular instructions with information about cellular metabolic resources and to control the rate of anabolic and catabolic processes accordingly. In mammalian cells mTOR is present in two distinct heteromeric protein complexes commonly referred to as mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2), involved in the control of a wide variety of cellular processes. It has been recently reported that compounds acting modulating mTOR activity, beside mediating the well recognized processes exploited in the anticancer and immunosuppressant effects, are provided with neuroprotective properties. In fact, mTOR is involved in the mechanism of PI3K/Akt-induced upregulation of glutamate transporter 1, GLT1, that is linked to several neuronal disorders such as stroke, Alzheimer's disease, and amyotrophic lateral sclerosis. Furthermore, in adult brain mTOR is crucial for numerous physiological processes such as synaptic plasticity, learning, memory, and brain control of food uptake. Moreover, the activation of mTOR pathway is involved in neuronal development, dendrite development and spine morphogenesis.

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.