Delayed introduction of reduced-dose tacrolimus, and renal function in liver transplantation: the 'ReSpECT' study

Calcineurin inhibitor sparing with mycophenolate mofetil in liver transplantion: a systematic review of randomized controlled trials

Liver transplant recipients are at high risk of developing acute and chronic renal failure. Moreover, introduction of the model for end-stage liver disease (MELD) score for primary allocation of liver grafts favors patients with pretransplant kidney dysfunction, which in turn have a higher risk of posttransplant renal failure. Calcineurin inhibitors (CNI) further increase the risk of renal failure and therefore sparing CNI with the use of mycophenolate mofetil (MMF) may improve renal function. MMF may either be used de novo in the immediate posttransplant period in combination with low-dose CNI (scenario 1) or patients that receive immunosuppression based on CNI may be converted to MMF in combination with minimization or elimination of CNI (scenario 2). Although many retrospective cohort studies and nonrandomized trials have implicated efficacy of this approach the evidence from randomized controlled studies has not been summarized. In the current review we report the results of a systematic review and meta-analysis of randomized controlled trials.

Tacrolimus trough levels, rejection and renal impairment in liver transplantation: a systematic review and meta-analysis

We hypothesized that current trough concentrations of tacrolimus after liver transplantation are set too high, considering that clinical consequences of rejection are not severe while side effects are increased.We systematically reviewed 64 studies (32 randomized controlled trials and 32 observational studies) to determine how lower tacrolimus trough concentrations than currently recommended affect acute rejection rates and renal impairment. Among randomized trials the mean of tacrolimus trough concentration during the first month was positively correlated with renal impairment within 1 year (r = 0.73; p = 0.003), but not with acute rejection, either defined using protocol biopsies (r = -0.37; p = 0.32) or not (r = 0.11; p = 0.49). A meta-analysis of randomized trials directly comparing tacrolimus trough concentrations (five trials for acute rejection [n = 957] and two trials for renal impairment [n = 712]) showed that "reduced tacrolimus" trough concentrations (<10 ng/mL) within the first month after liver transplantation were associated with less renal impairment at 1 year (RR = 0.51 [0.38-0.69]), with no significant influence on acute rejection (RR = 0.92 [0.65-1.31]) compared to "conventional tacrolimus" trough levels (>10 ng/mL). Lower trough concentrations of tacrolimus (6-10 ng/mL during the first month) would be more appropriate after liver transplantation. Regulatory authorities and the pharmaceutical industry should allow changes of regulatory drug information.

Current concepts in pediatric liver transplantation

Liver transplantation is the definitive treatment for end-stage liver disease in both children and adults. Advances over the last 2 decades have resulted in excellent patient and graft survival rates in what were previously cases of fatal disorders. These developments have been due to innovations in surgical technique, increased surgical experience, refinements in immunosuppressive regimens, quality improvements in intraoperative anesthetic management, better understanding of the pathophysiology of the liver diseases, and better preoperative and postoperative care. Remarkably, the use of split-liver and living-related liver transplantation surgical techniques has helped mitigate the well-recognized national organ shortage. This review will discuss the major aspects of pediatric liver transplantation as it pertains to indication for transplantation, recipient selection and listing for orthotopic liver transplantation, pre-orthotopic liver transplantation care of children, optimal timing of orthotopic liver transplantation, surgical technical considerations, postoperative care and complications, and patient and graft survival outcomes.

Review article: use of induction therapy in liver transplantation

Induction therapy is used relatively infrequently in liver transplantation, but developments in induction regimens and strategies for their use are prompting a re-examination of its benefits. Rabbit antithymocyte globulin (rATG) induces protracted, dose-dependent lymphocytopenia with preferential reconstitution of regulatory T-lymphocytes. Non-depleting interleukin-2 receptor antagonists (IL-2RA) act selectively on activated T-lymphocytes with a shorter duration of effect. IL-2RA induction with delayed and reduced calcineurin inhibitor (CNI) exposure appears to preserve efficacy, while more aggressive CNI minimisation has been attempted successfully using rATG. Steroid-free tacrolimus monotherapy with rATG or IL-2RA induction is effective if adequate tacrolimus exposure is maintained. Early concerns that addition of induction to a conventional maintenance regimen could lead to accelerated progression of hepatitis C disease, or to an increased risk of hepatocellular cancer recurrence, now appear unfounded using modern regimens. Similarly, with routine use of systemic prophylaxis, recent prospective and retrospective data have not shown a higher rate of infections overall, or cytomegalovirus infection specifically, using rATG or IL-2RA induction. Historical evidence that lymphocyte-depleting agents increased the risk of non-Hodgkin lymphoma has not been confirmed for rATG. Wider use of induction in liver transplantation is now merited, using individualized strategies to support reduced CNI exposure or steroid-free immunosuppression.

Outcomes of living donor liver transplantation for patients with preoperative type 1 hepatorenal syndrome and acute hepatic decompensation

This study investigated the outcomes of living donor liver transplantation (LDLT) for patients with preoperative type 1 hepatorenal syndrome (HRS) and acute hepatic decompensation. Prospectively collected data for 104 patients who had fulminant hepatic failure, acute decompensation of cirrhosis, or an acute flare of chronic hepatitis B were analyzed. Thirty-three patients (31.7%) had HRS (the HRS group), and 71 patients (68.3%) did not (the non-HRS group). The median follow-up period was 60 months. The HRS group had significantly more preoperative intensive care unit (ICU) admissions (84.8% versus 60.6%, P = 0.01), worse preoperative blood test results (creatinine, 248 versus 88 μmol/L, P < 0.001; total bilirubin, 630 versus 555 μmol/L, P = 0.001), more hemodialysis (48.5% versus 0%, P < 0.001), more blood transfusions (9 versus 4 U, P < 0.001), longer postoperative ICU stays (8 versus 4 days, P < 0.001), worse postoperative blood test results (creatinine at 1 year, 108 versus 96 μmol/L, P = 0.006), and poorer overall survival (P < 0.001). In a multivariate analysis, only HRS was associated with poorer overall survival (hazard ratio = 8.592, 95% confidence interval = 1.782-41.431, P = 0.007). In conclusion, HRS patients had worse postoperative renal function and overall survival than non-HRS patients. However, their 5-year overall survival rate was still nearly 80%, which is satisfactory. Therefore, LDLT can be considered for patients who have acute hepatic decompensation with or without HRS.

Glomerular and tubular function following orthotopic liver transplantation in children treated with tacrolimus

The aim of this study was to analyze the impact of TAC on medium term (three-yr follow-up) renal function in pediatric liver transplant (OLT) recipients. Glomerular and tubular indices were retrospectively analyzed in 24 consecutive OLT pediatric recipients on TAC. CrCl increased significantly each month post-OLT (p = 0.003), with a trend toward significance between pre-OLT and 36 months (p = 0.17). There was no correlation between CrCl and TAC troughs (p = 0.783). Sixteen percent of patients had CrCl <60 mL/min/1.73 m(2) pre-OLT vs. none at 36 months post-OLT. TRP values were normal throughout the study. UPr/Cr decreased insignificantly over time and correlated significantly with TAC trough levels (p = 0.031). UCa/Cr values normalized by the third-month post-OLT, decreasing significantly over the time (p = 0.000) but did not correlate with TAC troughs. At three months post-OLT, 65.2% of patients needed antihypertensive therapy, and no patients needed more than one antihypertensive treatment after one yr. Despite nephrotoxic side effects in the early postoperative phase, this study shows that 65.5% patients had a normal renal function by three yr post-OLT. Tubular indices correlated with TAC trough levels.

Donation after cardiac death liver transplant recipients have an increased frequency of acute kidney injury

Donation after cardiac death (DCD) liver transplantation is associated with an increased frequency of hepato-biliary complications. The implications for renal function have not been explored previously. The aims of this single-center study of 88 consecutive DCD liver transplant recipients were (1) to compare renal outcomes with propensity-risk-matched donation after brain death (DBD) patients and (2) in the DCD patients specifically to examine the risk factors for acute kidney injury (AKI; peak creatinine ≥2 times baseline) and chronic kidney disease (CKD; eGFR <60 mL/min/1.73 m(2) ). During the immediate postoperative period DCD liver transplantation was associated with an increased incidence of AKI (DCD, 53.4%; DBD 31.8%, p = 0.004). In DCD patients AKI was a risk factor for CKD (p = 0.035) and mortality (p = 0.017). The cumulative incidence of CKD by 3 years post-transplant was 53.7% and 42.1% for DCD and DBD patients, respectively (p = 0.774). Importantly, increasing peak perioperative aspartate aminotransferase, a surrogate marker of hepatic ischemia reperfusion injury, was the only consistent predictor of renal dysfunction after DCD transplantation (AKI, p < 0.001; CKD, p = 0.032). In conclusion, DCD liver transplantation is associated with an increased frequency of AKI. The findings suggest that hepatic ischemia reperfusion injury may play a critical role in the pathogenesis of post-transplant renal dysfunction.

Optimization of the use of Calcineurin inhibitors in liver transplantation

Calcineurin inhibitors (CNIs), such as cyclosporin A and tacrolimus, are the cornerstone of maintenance immunosuppressive regimens in liver transplantation. CNIs prevent rejection by inhibition of calcineurin, via which lymphocyte proliferation and interleukin (IL)-2 production is prevented. Tacrolimus is now the first-choice immunosuppressant after liver transplantation, since it is associated with fewer episodes of rejection than cyclosporin A. In this review we will discuss interindividual differences, which influence tacrolimus metabolism. Because of these factors and the narrow therapeutic index of tacrolimus, monitoring of drug trough levels is necessary. Furthermore, we will discuss studies concerning conversion from the tacrolimus twice daily to tacrolimus once daily formulation in stable LT patients. Due to adverse effects of CNIs, such as chronic renal failure, hypertension, de novo malignancy and new-onset diabetes mellitus, CNI minimization strategies have been developed, which will be discussed too.

Hot-topic debate on kidney function: renal-sparing approaches are beneficial

1. Renal function is frequently compromised in candidates for transplantation with advanced cirrhosis. These patients frequently have chronic and irreversible kidney changes at the time of transplantation. 2. The accumulated incidence of chronic renal failure is high in liver transplant recipients. Chronic renal failure has a deleterious impact on the outcome. 3. Calcineurin inhibitor (CNI)-based immunosuppression is highly effective at preventing rejection. However, CNI nephrotoxicity has a central role in the occurrence of chronic renal failure. 4. Renal function impairment frequently occurs within the first year after transplantation. Once renal function is significantly impaired [glomerular filtration rate (GFR) < 60 mL/minute/1.73 m(2) ], any intervention is unlikely to result in a return to normal renal function. Early interventions are needed to prevent chronic and irreversible kidney injury. 5. De novo CNI minimization has been proven to be effective at reducing the rate of impaired renal function after transplantation. The reduction in the CNI doses should be offset by the addition of mycophenolate mofetil or enteric-coated mycophenolate sodium. 6. Delayed CNI minimization in patients with established renal insufficiency may result in a significant improvement in the GFR, even though the increase in the GFR after minimization is generally modest. 7. Mammalian target of rapamycin (mTOR) inhibitors are considered nonnephrotoxic immunosuppressive agents. They may be an option for improving renal function in liver transplant recipients. However, not all patients with renal dysfunction benefit from a switch to mTOR inhibitors. In addition, the benefits in terms of renal function should be balanced against specific side effects. 8. New immunosuppressive agents without intrinsic nephrotoxicity are currently under development for solid organ transplantation. These agents could help to reduce the burden of impaired renal function in transplantation in the near future.

Present state of immunosuppressive therapy in liver transplant recipients

1. Our increasing understanding of the signaling pathways and cellular interactions in transplant immunobiology has facilitated targeted strategies using novel immunosuppressive agents. 2. The pattern of immunosuppressive drug use in the United States continues to change, and the changes include the use of antibody induction therapy and the agents used in maintenance therapy. 3. The driving forces behind the development of new immunosuppressive regimens are the long-term complications of current immunosuppressive regimens (particularly renal dysfunction and metabolic disturbances).

Hot-topic debate on kidney function: renal-sparing approaches are ineffective

1. Both acute kidney injury and chronic renal disease are common in patients undergoing liver transplantation. The etiologies are mixed. 2. The incidence of chronic renal failure after liver transplantation is unacceptable, and it has a significant impact on long-term outcomes after liver transplantation. 3. The role of calcineurin inhibitors (CNIs) in the development of posttransplant chronic renal failure is likely overrated. 4. The use of CNIs in the early posttransplant period is currently essential. 5. Whether new agents will be able to provide effective immunosuppression as primary immunosuppressives remains to be proven.

Renal function in patients undergoing transplantation for nonalcoholic steatohepatitis cirrhosis: time to reconsider immunosuppression regimens?

Nonalcoholic fatty liver disease is an independent risk factor for chronic kidney injury (CKI), yet the impact of liver transplantation (LT) on renal function in this at-risk group is not known. We compared the post-LT renal function of patients with nonalcoholic steatohepatitis (NASH) and a matched comparison group. Forty-eight consecutive patients who underwent transplantation for NASH between 2000 and 2008 in a single UK center were compared to non-NASH patients who were matched by age, sex, Model for End-Stage Liver Disease score, and estimated glomerular filtration rate (eGFR; calculated with the Modification of Diet in Renal Disease formula). In comparison with non-NASH patients, NASH patients had a significantly lower eGFR 3 months after LT (eGFR difference = 8.85 mL/minute/1.73 m(2), 95% confidence interval = 2.93-14.77). After adjustments for the effects of the body mass index, tacrolimus levels, diabetes mellitus, hypertension, and hepatocellular carcinoma, the difference between the groups remained significant 3 months after LT (P = 0.001). These data were then analyzed at numerous time points after LT (6, 12, and 24 months), and the time did not significantly affect the difference between the groups (P = 0.17). Within 2 years, 31.2% of the NASH patients (15/48) had developed stage IIIb CKI, whereas only 8.3% of the non-NASH patients (4/48) did (P = 0.009). In conclusion, this study has identified NASH as an independent risk factor for renal dysfunction after LT. Renal-sparing immunosuppression regimens should be considered at the time of LT to reduce the development of kidney injury in NASH patients. The optimization of such regimens requires a prospective study.

Chronic kidney disease after liver transplantation for acute liver failure is not associated with perioperative renal dysfunction

Renal dysfunction of acute liver failure (ALF) may have distinct pathophysiological mechanisms to hepatorenal syndrome of cirrhosis. Yet, the impact of perioperative renal function on posttransplant renal outcomes in ALF patients specifically has not been established. The aims of this study were (1) to describe the incidence and risk factors for chronic renal dysfunction following liver transplantation for ALF and (2) to compare renal outcomes with age-sex-matched patients transplanted for chronic liver disease. This was a single-center study of 101 patients transplanted for ALF. Fifty-three-and-a-half percent had pretransplant acute kidney injury and 64.9% required perioperative renal replacement therapy. After transplantation the 5-year cumulative incidence of chronic kidney disease (eGFR <60 mL/min/1.73 m²) was 41.5%. There was no association between perioperative acute kidney injury (p = 0.288) or renal replacement therapy (p = 0.134) and chronic kidney disease. Instead, the independent predictors of chronic kidney disease were older age (p = 0.019), female gender (p = 0.049), hypertension (p = 0.031), cyclosporine (p = 0.027) and nonacetaminophen-induced ALF (p = 0.039). Despite marked differences in the perioperative clinical condition and survival of patients transplanted for ALF and chronic liver disease, renal outcomes were the same. In conclusion, in patients transplanted for ALF the severity of perioperative renal injury does not predict posttransplant chronic renal dysfunction.

Interleukin 2 receptor antagonists for liver transplant recipients: a systematic review and meta-analysis of controlled studies

Interleukin 2 receptor antagonists (IL-2Ra) are frequently used as induction therapy in liver transplant recipients to decrease the risk of acute rejection while allowing the reduction of concomitant immunosuppression. We conducted a systematic review of prospective, controlled studies to test the hypothesis that the use of IL-2Ra is associated with a decrease in acute rejection and/or a decrease in the side effects of concomitant medication. We performed a search of all major databases and secondary sources from inception to December 2010. Random effects models were used to assess the incidence of acute rejection, graft loss, patient death, and adverse side effects, with or without IL-2Ra. Subgroup analysis and meta-regression were used to explore differences in effect and sources of heterogeneity. Eighteen studies (13 randomized and 5 nonrandomized) met the inclusion and exclusion criteria. Acute rejection at 12 months or later favored the use of IL-2Ra (relative risk [RR] 0.83; 95% confidence interval [CI] 0.76-0.94) and steroid-resistant rejection was also less frequent in patients receiving IL-2Ra (RR 0.66; CI 0.48-0.91). Graft loss and patient death did not differ significantly between treatments. Patients who received IL-2Ra in addition to reduced or delayed calcineurin inhibitors had better renal function (mean difference of estimated glomerular filtration rate: 6.29 mL/min; CI 1.66-10.91) and a lower incidence of renal dysfunction (RR 0.46; CI 0.27-0.78). The use of IL-2Ra was also associated with a lower incidence of posttransplant diabetes mellitus, whereas the incidence of other adverse events was similar.

CONCLUSION

The use of IL-2Ra is associated with a lower incidence of acute rejection after transplantation. Concomitant immunosuppression can be reduced, avoiding long-term side effects of immunosuppression.

How long should initiation of calcineurin inhibitors be delayed to protect renal function in liver transplantation?

BACKGROUND AND AIM

Delayed introduction of calcineurin inhibitors (CNI) in liver transplantation (OLT) seeks to protect renal function, although the optimal length of the delay is not well established. The aim of this study was to analyze the effects on renal function of CNI initiation on different days after OLT.

METHODS

We reviewed the charts of 260 OLT recipients. Group D1-a (n = 36) underwent the standard initial immunosuppression at our center: namely, CNI introduction on day 1 with further daily administration to achieve target levels of 8 to 15 ng/mL for tacrolimus or 150 to 300 ng/mL for cyclosporine. Due to renal concerns, 126 patients (group D1-b) had CNI introduced on day 1 either not daily or at doses to achieve less than the target on at least two occasions. In 43 patients (group D2), CNI were introduced on day 2 in 23 on day 3 (group D3), in 12 on day 4 (group D4), and at least at day 5 in 20 others (group D5). In periods without CNI treatment, patients received mycophenolate mofetil. Steroids were administered to all patients. The study period included the first 3 months post-OLT. Renal function was estimated as creatinine clearance (CrCl) using the Cockcroft-Gault equation.

RESULTS

Changes in CrCl from pre-OLT to month 3 were -19% ± 28% in group D1-a; -27% ± 19% in group D1-b; -29% ± 19% in group D2; -23% ± 26% in group D3; -4% ± 38% in group D4, and +4% ± 33% in group D5 (P < .05 vs groups D1-a, D1-b, D2, and D3). On multivariate analysis, CNI introduction at day ≥ 5 was protective for kidneys when adjusted for other variables that potentially influence renal function.

CONCLUSION

CNI should be introduced at day 5 after OLT to protect renal function.

Safety and feasibility of third-party multipotent adult progenitor cells for immunomodulation therapy after liver transplantation--a phase I study (MISOT-I)

BACKGROUND

Liver transplantation is the definitive treatment for many end-stage liver diseases. However, the life-long immunosuppression needed to prevent graft rejection causes clinically significant side effects. Cellular immunomodulatory therapies may allow the dose of immunosuppressive drugs to be reduced. In the current protocol, we propose to complement immunosuppressive pharmacotherapy with third-party multipotent adult progenitor cells (MAPCs), a culture-selected population of adult adherent stem cells derived from bone marrow that has been shown to display potent immunomodulatory and regenerative properties. In animal models, MAPCs reduce the need for pharmacological immunosuppression after experimental solid organ transplantation and regenerate damaged organs.

METHODS

Patients enrolled in this phase I, single-arm, single-center safety and feasibility study (n = 3-24) will receive 2 doses of third-party MAPCs after liver transplantation, on days 1 and 3, in addition to a calcineurin-inhibitor-free "bottom-up" immunosuppressive regimen with basiliximab, mycophenolic acid, and steroids. The study objective is to evaluate the safety and clinical feasibility of MAPC administration in this patient cohort. The primary endpoint of the study is safety, assessed by standardized dose-limiting toxicity events. One secondary endpoint is the time until first biopsy-proven acute rejection, in order to collect first evidence of efficacy. Dose escalation (150, 300, 450, and 600 million MAPCs) will be done according to a 3 + 3 classical escalation design (4 groups of 3-6 patients each).

DISCUSSION

If MAPCs are safe for patients undergoing liver transplantation in this study, a phase II/III trial will be conducted to assess their clinical efficacy.

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.

Long-term results of liver transplantation

Liver transplantation (LT) is an established therapy associated with a dramatic improvement in patients life expectancy. With improved early-term management, current 10-year patient survival rates in many indications exceed 70%. Life-long immunosuppressive therapy may, however, be accompanied by considerable longterm toxicity: most importantly, renal dysfunction, cardiovascular disease, and cancer, which, in addition to recurrence of the primary liver disease, emerge as key contributors to late mortality. Chronic kidney disease cumulatively affects up to 28% of patients by ten years after LT. Various factors can contribute to renal impairment, but perioperative acute kidney injury, calcineurin inhibitor toxicity, hypertension, and diabetes are considered most important. LT patients demonstrate 3-fold risk for cardiovascular events, which seems to result mostly from an excess of traditional risk factors, mainly hypertension and diabetes. The cumulative cancer incidence reaches 16-42% by 20 years after LT, and cancer rates are 2- to 4-fold higher among LT patients than among matched controls. Highest rates are for nonmelanoma skin cancer (3- to 70-fold) and lymphoma (8- to 29-fold). The liver graft usually displays uncomplicated function in the long term. Most common causes for chronic graft dysfunction include disease recurrence and biliary problems. LT generally restores patients quality of life to a level comparable with that of the general population, with only minor deficits in some areas. Thus, long-term survival after LT is impressive, and despite these long-term complications, patients quality of life remains comparable with that of the general population.

Finding the right time for weaning off immunosuppression in solid organ transplant recipients

Solid organ transplantation (SOT) requires lifelong immunosuppression (IS) to prevent rejection and graft loss. The currently adopted immunosuppressive protocols are numerous and are based on the administration of at least two molecules with diverse mechanisms of action. Owing to the fact that the majority of immunosuppressants act non-selectively, the immune system is normally oversuppressed, and as a result is less able to both defend the host against infection and to control the spread of malignant cells. Consequently, long-term IS is burdened by chronic toxicity, which may be highly invalidating and may significantly influence patient's quality of life, compliance to treatment, overall success rate, and patient and graft survival. In an ideal scenario, SOT recipients should initially receive just enough IS to favor the onset of clinical operational tolerance (COT), a condition where the immune system of the host does not attack the graft in the absence of any immunosuppressant. COT has been documented after liver transplantation (LT) and renal transplantation (RT). First, COT was accidentally detected in patients who were nonadherent to treatment and who spontaneously decided to stop all IS without any medical guidance or surveillance. Later, it was described in recipients who required IS withdrawal following the occurrence of malignant diseases. Based on strikingly convincing experimental data, several tolerogenic protocols have recently been applied in patients but overall the results have been disappointing. The current literature demonstrates that COT can be safely achieved in stable LT recipients, with completely different strategies. Importantly, the onset of an episode of acute rejection during the attempt of IS withdrawal would not worsen the clinical outcome. On the contrary, COT remains a major challenge after RT because the onset of acute rejection will substantiate in graft loss. Currently, a major field of investigation aims to define markers of COT, which will allow the selection of individuals who are more prone to develop COT. Preliminary results in both RT and LT have just been announced; however, these markers will require validation in prospective studies.

Reduced-dose tacrolimus with mycophenolate mofetil vs. standard-dose tacrolimus in liver transplantation: a randomized study

We conducted a multicenter randomized study in liver transplantation to compare standard-dose tacrolimus to reduced-dose tacrolimus with mycophenolate mofetil to reduce the occurrence of tacrolimus side effects. Two primary outcomes (censored criteria) were monitored during 48 weeks post-transplantation: occurrence of renal dysfunction or arterial hypertension or diabetes (evaluating benefit) and occurrence of acute graft rejection (evaluating risk). Interim analyses were performed every 40 patients to stop the study in the case of increased risk of graft rejection. One hundred and ninety-five patients (control: 100; experimental: 95) had been included when the study was stopped. Acute graft rejection occurred in 46 (46%) and 28 (30%) patients in control and experimental groups, respectively (HR = 0.59; 95% CI: [0.37-0.94]; p = 0.024). Renal dysfunction or arterial hypertension or diabetes occurred in 80 (80%) and 61 (64%) patients in control and experimental groups, respectively (HR = 0.68; 95% CI: [0.49-0.95]; p = 0.021). Renal dysfunction occurred in 42 (42%) and 23 (24%) patients in control and experimental groups, respectively (HR = 0.49; 95% CI: [0.29-0.81]; p = 0.004). Leucopoenia (p = 0.001), thrombocytopenia (p = 0.017) and diarrhea (p = 0.002) occurred more frequently in the experimental group. Reduced-dose tacrolimus with mycophenolate mofetil reduces the occurrence of renal dysfunction and the risk of graft rejection. This immunosuppressive regimen could replace full-dose tacrolimus in adult liver transplantation.

Mycophenolate monitoring in liver, thoracic, pancreas, and small bowel transplantation: a consensus report

Assessing the value of mycophenolic acid (MPA) monitoring outside renal transplantation is hindered by the absence of any trial comparing fixed-dose and concentration-controlled therapy. However, in liver and thoracic transplantation particularly, clinical trials, observational studies with comparison groups, and case series have described MPA efficacy, exposure/efficacy relationships, pharmacokinetic variability, and clinical outcomes relating to plasma MPA concentrations. On the basis of this evidence, this report identifies MPA as an immunosuppressant for which the combination of variable disposition, efficacy, and adverse effects contributes to interindividual differences seemingly in excess of those optimal for a fixed-dosage mycophenolate regimen. Combined with experiences of MPA monitoring in other transplant indications, the data have been rationalized to define circumstances in which measurement of MPA concentrations can contribute to improved management of mycophenolate therapy in nonrenal transplant recipients.

Renal function in the long term after pediatric liver transplantation: is there a need for protocol kidney biopsies?

PURPOSE OF REVIEW

With improving survival rates following solid organ transplantation, assessment of its success has broadened with a focus on long-term outcomes, including nongraft-related medical outcomes and family and patient perceptions of quality of life. Posttransplant renal dysfunction contributes to long-term morbidity and mortality following pediatric liver transplantation. In this review, we provide an overview of our understanding and approach to managing posttransplant renal dysfunction and highlight the existing gaps in knowledge in this area.

RECENT FINDINGS

The literature regarding renal dysfunction following liver transplant primarily focuses on the experience in the adult population. Studies on children are limited by small numbers and varying definitions of outcomes. Thus, lessons in the current literature must be closely examined before they can be extrapolated and applied to children.

SUMMARY

The current literature validates that posttransplant renal dysfunction is a frequent and important outcome for adults and children. Although the characteristics of children at high risk are less clear, calcineurin inhibitor minimization is considered a viable strategy for preserving renal function. The risk-benefit ratio of kidney biopsy in children and the possibility of renal preservation via immunosuppression withdrawal are intriguing concepts that remain to be defined.

The renal benefit of mycophenolate mofetil after liver transplantation

BACKGROUND

The risk and benefit of adding mycophenolate mofetil (MMF) to a standard immunosuppressive regimen at the time of liver transplantation (LT) is not well described.

METHODS

We performed a retrospective case-control analysis comparing one-yr outcomes of all LT recipients at our institution treated with post-operative tacrolimus (TAC), MMF, and steroids vs. TAC and steroids.

RESULTS

A total of 101 LT recipients (50:51 case:control) were analyzed. Despite more renal dysfunction at LT, the MMF + TAC group had similar serum creatinine (Cr) and glomerular filtration rate (GFR) as the TAC group one-yr post-LT. In this time period, Cr decreased (1.57-1.22 mg/dL, p = 0.04) and GFR increased (57.5-65.1 mL/min per 1.73 m(2), p = 0.05) in the MMF + TAC group, while Cr increased (1.11-1.35, p < 0.01) and GFR declined (73.5-60.1, p < 0.001) in the TAC group. These findings occurred without a difference in absolute rejection episodes, hospitalizations, infections, deaths, or time to above events (p > 0.05). Subgroup analysis of patients stratified by pre-transplant renal dysfunction (Cr ≥ 1.2 mg/dL) supported the previous. MMF was reasonably well tolerated with a low rate of discontinuation.

CONCLUSIONS

The use of adjunctive MMF immediately after LT may protect against calcineurin inhibitor nephrotoxicity, potentially without the need for dose reduction or increased risk of adverse events.

ATG-Fresenius treatment and low-dose tacrolimus: results of a randomized controlled trial in liver transplantation

We report the results of a prospective randomized controlled trial in liver transplantation assessing the efficacy and safety of antithymocyte globulin (ATG-Fresenius) plus tacrolimus monotherapy at gradually decreasing doses. Patients were randomized to either: (a) standard-dose tacrolimus plus steroids;or (b) peritransplant ATG-Fresenius plus reduced-dose tacrolimus monotherapy followed by weaning of tacrolimus starting 3 months after transplantation. The primary end-point was the achievement of very low-dose tacrolimus (every-other-day or once daily dose with <5 ng/mL trough levels) at 12 months after transplantation. Acute rejection occurring during the first 3 months after transplantation was more frequent in the ATG group (52.4% vs. 25%). Moreover, late acute rejection episodes occurred in all recipients in whom weaning was attempted and no recipients reached the primary end-point. This motivated the premature termination of the trial. Tacrolimus trough levels were lower in the ATG-Fresenius group but no benefits in terms of improved renal function, lower metabolic complications or increased prevalence of tolerance-related biomarkers were observed. In conclusion, the use of ATG-Fresenius and tacrolimus at gradually decreasing doses was associated with a high rate of rejection, did not allow for the administration of very low doses of tacrolimus and failed to provide detectable clinical benefits. ClinicalTrials.gov identifier: NCT00436722.

Study protocol: a pilot study to determine the safety and efficacy of induction-therapy, de novo MPA and delayed mTOR-inhibition in liver transplant recipients with impaired renal function. PATRON-study

BACKGROUND

Patients undergoing liver transplantation with preexisting renal dysfunction are prone to further renal impairment with the early postoperative use of Calcineurin-inhibitors. However, there is only little scientific evidence for the safety and efficacy of de novo CNI free "bottom-up" regimens in patients with impaired renal function undergoing liver transplantation. This is a single-center study pilot-study (PATRON07) investigating safety and efficacy of CNI-free, "bottom-up" immunosuppressive (IS) strategy in patients undergoing liver transplantation (LT) with renal impairment prior to LT.

METHODS/DESIGN

Patients older than 18 years with renal impairment at the time of liver transplantation eGFR < 50 ml/min and/or serum creatinine levels > 1.5 mg/dL will be included. Patients in will receive a CNI-free combination therapy (basiliximab, MMF, steroids and delayed Sirolimus). Primary endpoint is the incidence of steroid resistant acute rejection within the first 30 days after LT. The study is designed as prospective two-step trial requiring a maximum of 29 patients. In the first step, 9 patients will be included. If 8 or more patients show no signs of biopsy proven steroid resistant rejection, additional 20 patients will be included. If in the second step a total of 27 or more patients reach the primary endpoint the regimen is regarded to be safe and efficient.

DISCUSSION

If a CNI-free-"bottom-up" IS strategy is safe and effective, this may be an innovative concept in contrast to classic top-down strategies that could improve the patient short and long-time renal function as well as overall complications and survival after LT. The results of PATRON07 may be the basis for a large multicenter RCT investigating the new "bottom-up" immunosuppressive strategy in patients with poor renal function prior to LT.http://www.clinicaltrials.gov-identifier: NCT00604357.

Daclizumab induction therapy in liver transplant recipients with renal insufficiency

BACKGROUND

The role of interleukin 2 (IL-2) receptor antibodies to avoid the nephrotoxic effects of calcineurin inhibitors in the early post-liver transplant (LT) period is not well defined.

AIM

To examine the use of daclizumab induction in LT recipients with renal insufficiency.

METHODS

Between 2002 and 2005, 62 patients (median pre-LT creatinine 2.4 mg/dL, IQR 1.9-3.7) received daclizumab induction with tacrolimus being administered when serum creatinine was <2.0 mg/dL. A concurrent comparison group (n = 221, 2002-2005) received tacrolimus-based immunosuppression without daclizumab (median pre-LT creatinine 1.1 mg/dL, IQR 0.9-1.4). A second historical comparison group (n = 103, 1995-2005) not receiving daclizumab was matched to the daclizumab patients by pre-LT serum creatinine (2.2 mg/dL, IQR 1.8-3.1). All patients received mycophenolate mofetil and steroids.

RESULTS

Serum creatinine improved in the daclizumab group (-1.0 mg/dL, IQR -2.2 to -0.4) and worsened in the concurrent comparison group (+0.2 mg/dL, IQR 0-0.5) from pre-LT to 4 months. However, there was no difference when daclizumab group was compared with the historical comparison group matched on pre-LT creatinine (median change: -0.8 mg/dL vs. -0.7 mg/dL). Daclizumab induction was not associated with improvement in renal function at 4 months (P = 0.34) after adjusting for pre-LT creatinine, age, gender, hepatitis C status and simultaneous liver kidney transplantation.

CONCLUSION

The incremental benefit offered by induction therapy with IL-2 receptor antibodies to preserve renal function is questionable.

Interleukin-2 receptor blockade with humanized monoclonal antibody for solid organ transplantation

IMPORTANCE OF THE FIELD

Induction therapy has reduced the incidence of acute rejection compared with historical standards. The potency of currently available induction immunosuppression is not without risk and should be carefully considered. Induction with daclizumab, an IL-2 receptor antagonist, has been used safely and effectively for over 10 years across different transplant types. As a result of daclizumab use, transplant centers are able to implement steroid-sparing or calcineurin minimization protocols. Unfortunately, the manufacturing costs have resulted in withdrawal of this agent from the market reducing the options for patients undergoing transplantation.

AREAS COVERED IN THIS REVIEW

This review will update the reader on recently published daclizumab studies in adult solid organ transplant recipients, focusing on comparative studies with other induction agents.

WHAT THE READER WILL GAIN

This paper will provide a summary of comparative studies between daclizumab and other induction therapies focusing on their efficacy and safety.

TAKE HOME MESSAGE

Novel applications, such as long-term use in combination with calcineurin-inhibitor dose reduction and its value in the treatment of acute or chronic rejection have yet to be explored. Since daclizumab has been withdrawn from the market, future IL-2 receptor blockade will have to be achieved with basiliximab, which is a chimeric, monoclonal antibody directed against the same epitope.

A therapeutic exploratory study to determine the efficacy and safety of calcineurin-inhibitor-free de-novo immunosuppression after liver transplantation: CILT

Background

Immunosuppression with calcineurin inhibitors (CNI) increases the risk of renal dysfunction after orthotopic liver transplantation (OLT). Controlled trials have shown improvement of renal function in patients that received delayed and/or reduced-dose CNI after OLT. Delaying immunosuppression with CNI in combination with induction therapy does not increase the risk of acute rejection but reduces the incidence of acute renal dysfunction. Based on this clinical data this study protocol was designed to assess the efficacy and safety of calcineurin-inhibitor-free de-novo immunosuppression after liver transplantation.

Methods/Design

A prospective therapeutic exploratory, non-placebo controlled, two stage monocenter trial in a total of 29 liver transplant patients was designed to assess the safety and efficacy of de-novo CNI-free immunosuppression with basiliximab, mycophenolate sodium, prednisolone and everolimus. The primary endpoint is the rate of steroid resistant rejections. Secondary endpoints are the incidence of acute rejection, kidney function (assessed by incidence and duration of renal replacement therapy, incidence of chronic renal failure, and measurement glomerular filtration rate), liver allograft function (assessed by measurement of AST, ALT, total bilirubin, AP, GGT), treatment failure, (i. e., re-introduction of CNI), incidence of adverse events, and mortality up to one year after OLT.

Discussion

This prospective, two-stage, single-group pilot study represents an intermediate element of the research chain. If the data of the phase II study corroborates safety of de-novo CNI-free immunosuppressive regimen this should be confirmed in a randomized, prospective, controlled double-blinded clinical trial. The exploratory data from this trial may then also facilitate the design (e. g. sample size calculation) of this phase III trial.

Trial registration number

NCT00890253 (clinicaltrials.gov)

Sirolimus-based immunosuppression is associated with increased survival after liver transplantation for hepatocellular carcinoma

Liver transplantation is an important treatment option for selected patients with nonresectable hepatocellular carcinoma (HCC). Several reports have suggested a lower risk of posttransplant tumor recurrence with the use of sirolimus and a higher one with calcineurin inhibitors, but the selection of an ideal immunosuppression protocol is still a matter of debate. The aim of this study was to define the immunosuppression associated with the best survival after liver transplantation for HCC. It was based on the Scientific Registry of Transplant Recipients and included 2,491 adult recipients of isolated liver transplantation for HCC and 12,167 for non-HCC diagnoses between March 2002 and March 2009. All patients remained on stable maintenance immunosuppression protocols for at least 6 months posttransplant. In a multivariate analysis, only anti-CD25 antibody induction and sirolimus-based maintenance therapy were associated with improved survivals after transplantation for HCC (hazard ratio [HR] 0.64, 95% confidence interval [CI]: 0.45-0.9, P < or = 0.01; HR 0.53, 95% CI: 0.31-0.92, P < or = 0.05, respectively). The other studied drugs, including calcineurin inhibitors, did not demonstrate a significant impact. In an effort to understand whether the observed effects were due to a direct impact of the drug on tumor or more on liver transplant in general, we conducted a similar analysis on non-HCC patients. Although anti-CD25 induction was again associated with a trend toward improved survival, sirolimus showed a trend toward lower rates of survival in non-HCC recipients, confirming the specificity of its beneficial impact to cancer patients.

CONCLUSION

According to these data, sirolimus-based immunosuppression has unique posttransplant effects on HCC patients that lead to improved survival.

Nonimmune complications after transplantation

As posttransplant longevity has increased, nonimmune complications related to the transplant and posttransplant course have emerged as important factors in defining long-term outcomes. The incidence of, and risk factors for these complications may vary by transplanted organ based on immunosuppressive protocols and preexisting risk factors. This article discusses the relevant nonimmune complications associated with posttransplant care, with a focus on risk factors and management strategies.

Renal dysfunction in chronic liver disease

This article is one of ten reviews selected from the Yearbook of Intensive Care and Emergency Medicine 2010 (Springer Verlag) and co-published as a series in Critical Care. Other articles in the series can be found online at http://ccforum.com/series/yearbook. Further information about the Yearbook of Intensive Care and Emergency Medicine is available from http://www.springer.com/series/2855.

Immunosuppression with low-dose daclizumab in liver transplant recipients with impaired kidney function: a single-center experience

BACKGROUND

Nephrotoxicity of calcineurin inhibitors (CNI) may exert detrimental effects, particularly in orthotopic liver transplantation (OLT) patients with impaired kidney function. Immunosuppression with daclizumab permits delayed introduction of CNI, and may be preferred for patients with kidney dysfunction. This retrospective analysis of our experience using daclizumab was performed among patients who underwent transplantation with impaired kidney function.

METHODS

We analyzed 168 patients. A serum creatinine (Cr) level >1.5 mg/dL was the indication for a protocol with low-dose daclizumab (50 mg intravenous [IV], day 0 and day 4), mycophenolate mofetil (MMF; 500 mg twice daily IV/orally), and tapering doses of prednisolone from day 0 after OLT. CNI were introduced at day 4-15 after OLT. Patients with a Cr level <1.5 mg/dL received immunosuppression with CNI+MMF+steroids or CNI+steroids.

RESULTS

Fourteen patients fulfilled the criterion for daclizumab immunosupression. Their Cr and creatinine clearance (CrCl) values at OLT were 2.85 +/- 1.22 mg/dL and 19 +/- 11 mL/min, respectively. In the remaining 154 patients, Cr and CrCl results were 0.88 +/- 0.3 mg/dL and 107 +/- 82 mL/min, respectively. At discharge, the daclizumab group showed Cr and CrCl estimates of 0.97 +/- 0.45 mg/dL and 86 +/- 34 mL/min (P < .0001 for both, when compared with prior to OLT). Both Cr and CrCl levels at discharge were not different from those values of patients who underwent transplantation with normal kidney function. The incidence of acuterejection was 14% in the daclizumab group and 18% in the other recipients (P = not significant [NS]).

CONCLUSIONS

Immunosuppression with low-dose daclizumab and delayed introduction of CNI was safe and did not increase the risk of an acute rejection episode, thus offerring an excellent therapeutic option for patients who undergo transplantation with impaired kidney function.

Mesenchymal stem cells as immunomodulators after liver transplantation

Mesenchymal stem cells (MSCs) are promising candidate cells for immunomodulation therapy that are currently being tested in the preclinical and clinical setting. MSCs suppress the immune response in a variety of in vitro and disease models and may thus be of benefit for patients suffering from autoimmune disorders or transplant rejection. The mechanism by which MSCs modulate the immune response is still under thorough investigation, but it most likely involves expression of local factors such as indoleamine 2,3-dioxygenase, inducible nitric oxide synthase, and others as well as interactions with dendritic or antigen-presenting cells. Although MSCs have been evaluated in clinical phase I and II studies for graft-versus-host disease and heart, kidney, and bone disease, their introduction into solid organ transplantation is still eagerly awaited. In this short review, we summarize the current understanding of immunomodulation achieved by MSC therapies and introduce a possible outline for a clinical study that will use MSCs in the context of a calcineurin inhibitor-free induction protocol after liver transplantation.

Renal impairment after liver transplantation - a pilot trial of calcineurin inhibitor-free vs. calcineurin inhibitor sparing immunosuppression in patients with mildly impaired renal function after liver transplantation

Objectives

Chronic kidney disease is frequent in patients after orthotopic liver transplantation (OLT) and has impact on survival. Patients receiving calcineurin inhibitors (CNI) are at increased risk to develop impaired renal function. Early CNI reduction and concomitant use of mycophenolat mofetil (MMF) has been shown to improve renal function.

Methods

The aim of this trial was to compare dose-reduced CNI/MMF versus CNI-free MMF/prednisone-based treatment in stable patients after OLT with respect to glomerular filtration rate (GFR). 21 patients [GFR 44.9 ± 9.9 mL/min/1.73 m² measured by 99m-Tc-DTPA-clearance, serum creatinine (SCr) 1.5 ± 0.42 mg/dL] were randomized either to exchange CNI for 10 mg prednisone (group 1; n = 8) or to receive CNI at 25% of the initial dose (group 2; n = 13) each in combination with 1000 mg MMF b.i.d.

Results

At month 12 mean SCr (-0.3 ± 0.4 mg/dL, p = 0.031) and GFR improved (8.6 ± 13.1 mL/min/1.73 m², p = 0.015) in group 2 but remained unchanged in group 1. Main side effects were gastroinstestinal symptoms (14.3%) and infections (4.8%). Two biopsy proven, steroid-responsive rejections occurred. In group 1 mean diastolic blood pressure (BP) increased by 11 ± 22 mmHg (p = 0.03).

Conclusions

Reduced dose CNI in combination with MMF but not CNI-free-immunosuppression leads to improvement of GFR in patients with moderately elevated SCr levels after OLT. Addition of steroids resulted in increased diastolic blood pressure presumably counterbalancing the benefits of CNI withdrawal on renal function.