Calcineurin inhibitor minimization in the Symphony study: observational results 3 years after transplantation

[Modern immunosuppression after solid organ transplantation]

The one common factor in solid organ transplantation is the need for lifelong maintenance immunosuppression. Drug regimens after organ transplantation typically comprise a combination of different immunosuppressive drugs. In most cases a triple drug regimen with different mechanisms of action is used. The aim is to improve both patient and graft survival while minimizing potential side effects of immunosuppressive medication. The basis of most immunosuppressive regimens is calcineurin inhibitors in combination with mycophenolic acid. There are various stages of immunosuppression after solid organ transplantation involving induction therapy, initial and long-term maintenance therapy. In each phase an individual combination of immunosuppressants is set up depending on the risk profile of the individual patient to prevent transplant rejection and organ loss. Based on these considerations, concepts of calcineurin inhibitor or steroid reduction have been established in transplant medicine in recent years. The key role in terms of development of new immunosuppressive strategies is taken by kidney transplantation, the most common solid organ transplantation performed.

The tacrolimus metabolism rate influences renal function after kidney transplantation

The effective calcineurin inhibitor (CNI) tacrolimus (Tac) is an integral part of the standard immunosuppressive regimen after renal transplantation (RTx). However, as a potent CNI it has nephrotoxic potential leading to impaired renal function in some cases. Therefore, it is of high clinical impact to identify factors which can predict who is endangered to develop CNI toxicity. We hypothesized that the Tac metabolism rate expressed as the blood concentration normalized by the dose (C/D ratio) is such a simple predictor. Therefore, we analyzed the impact of the C/D ratio on kidney function after RTx. Renal function was analyzed 1, 2, 3, 6, 12 and 24 months after RTx in 248 patients with an immunosuppressive regimen including basiliximab, tacrolimus, mycophenolate mofetil and prednisolone. According to keep the approach simple, patients were split into three C/D groups: fast, intermediate and slow metabolizers. Notably, compared with slow metabolizers fast metabolizers of Tac showed significantly lower estimated glomerular filtration rate (eGFR) values at all the time points analyzed. Moreover, fast metabolizers underwent more indication renal biopsies (p = 0.006) which revealed a higher incidence of CNI nephrotoxicity (p = 0.015) and BK nephropathy (p = 0.024) in this group. We herein identified the C/D ratio as an easy calculable risk factor for the development of CNI nephrotoxicity and BK nephropathy after RTx. We propose that the simple C/D ratio should be taken into account early in patient's risk management strategies.

Risk of metabolic complications in kidney transplantation after conversion to mTOR inhibitor: a systematic review and meta-analysis

Mammalian target of rapamycin (mTOR) inhibitors have been used in transplantation with the hope of minimizing calcineurin inhibitor (CNI)-induced nephrotoxicity. However, mTOR inhibitors are also associated with a range of side effects, including metabolic complications. We aimed to determine the risks of metabolic complications after the conversion from CNI to mTOR inhibitor postkidney transplant. A systematic search in PubMed up to September 2013 identified nine relevant trials (a total of 2323 patients). The primary end points were the relative risks (RRs) of new-onset diabetes after transplant (NODAT) and hypercholesterolemia. The overall RRs of NODAT and hypercholesterolemia associated with mTOR inhibitors were 1.32 (95% confidence interval [CI] 0.92-1.87) and 2.15 (95% CI 1.35-3.41), respectively, compared with CNI-based regimen. Subgroup analyses revealed no differences in the incidence of NODAT or hypercholesterolemia between sirolimus- versus everolimus-based regimen, or between early versus late conversion. Analyses of secondary outcomes revealed a higher risk of acute rejection, proteinuria and anemia, but no difference in the risk of opportunistic infections after mTOR inhibitor conversion. In conclusion, the conversion from CNI to mTOR inhibitor in low-to-moderate risk kidney transplant recipients was associated with nonsignificant trend toward increased risk of NODAT and significant increase in hypercholesterolemia, acute rejection, proteinuria and anemia.

A randomized cross-over comparison of short-term exposure of once-daily extended release tacrolimus and twice-daily tacrolimus on renal function in healthy volunteers

Calcineurin inhibitor nephrotoxicity remains an issue for transplant recipients. The pharmacokinetic profile (PK) of the once-daily tacrolimus extended release (Tac-ER) includes equivalent exposure [AUC(0-24 h) ] but lower Cmax versus twice-daily tacrolimus immediate release (Tac-IR). We hypothesized that the unique PK profiles would result in pharmacodynamic differences in renal function. Nineteen healthy male subjects were allocated to once-daily Tac-ER and twice-daily Tac-IR in a prospective, randomized, two period, cross-over study. Tacrolimus was titrated to achieve trough levels of 8-12 ng/ml. Twenty four hours ERPF and GFR estimated by para-aminohippurate and sinistrin clearance were performed at baseline and at the end of each 10-day dosing period. Mean Tac C0 was 11.0 ± 2.2 and 11.3 ± 1.8 ng/ml for Tac-ER and Tac-IR, respectively. The mean Effective 24 h renal plasma flow (ERPF) was significantly higher with Tac-ER compared with Tac-IR (658 ± 127 vs. 610 ± 93 ml/min/1.73 m(2) , P = 0.046). There was a trend to a greater mean GFR over 24 h for Tac-ER at 114.5 ± 13.6 ml/min/1.73 m(2) compared with 108.9 ± 9.7 ml/min/1.73 m(2) for Tac-IR, P = 0.116. Under controlled physiological conditions, ERPF was significantly improved with Tac-ER compared with Tac-IR, likely owing to the differing PKs of these tacrolimus preparations (ClinicalTrials.gov Identifier: NCT01681134).

15-year follow-up of a multicenter, randomized, calcineurin inhibitor withdrawal study in kidney transplantation

BACKGROUND

Calcineurin inhibitors (CNIs) are essential immunosuppressive drugs after renal transplantation. Because of nephrotoxicity, withdrawal has been a challenge since their introduction.

METHODS

A randomized multicenter trial included 212 kidney patients transplanted between 1997 and 1999. All patients were initially treated with mycophenolate mofetil (MMF), cyclosporine A (CsA), and prednisone (pred). At 6 months after transplantation, 63 patients were randomized for MMF/pred, 76 for MMF/CsA, and 73 for MMF/CsA/pred. Within 18 months after randomization 23 patients experienced a rejection episode: MMF/pred (27.0%), MMF/CsA (6.8%) and MMF/CsA/pred (1.4%) (P<0.001).

RESULTS

During 15 years of follow-up, 73 patients died with a functioning graft, and 43 patients lost their graft. Ninety-six were alive with a functioning graft. Intention-to-treat analysis did not show a significant difference in patient and graft survival. In multivariate analysis, death-censored graft survival was significantly associated with serum creatinine at 6 months after transplantation and maximum PRA but not with the randomization group. CNI withdrawal did not result in a reduced incidence of or death by malignancy or cardiovascular disease. Death-censored graft survival was significantly worse in those patients randomized for CNI withdrawal that had to be reverted to CNI. Independent of randomization group, compared with no rejection, death-censored graft survival was significantly worse in 23 patients with acute rejection after randomization.

CONCLUSION

Fifteen years after conversion to a CNI free regimen, there was no benefit regarding graft and patient survival or regarding prevalence of or death by comorbidities. However, rejection shortly after CNI withdrawal was associated with decreased graft survival.

mTOR inhibitors and dyslipidemia in transplant recipients: a cause for concern?

Post-transplant dyslipidemia is exacerbated by mammalian target of rapamycin (mTOR) inhibitors. Early clinical trials of mTOR inhibitors used fixed dosing with no concomitant reduction in calcineurin inhibitor (CNI) exposure, leading to concerns when consistent and marked dyslipidemia was observed. With use of modern concentration-controlled mTOR inhibitor regimens within CNI-free or reduced-exposure CNI regimens, however, the dyslipidemic effect persists but is less pronounced. Typically, total cholesterol levels are at the upper end of normal, or indicate borderline risk, in kidney and liver transplant recipients, and are lower in heart transplant patients under near-universal statin therapy. Of note, it is possible that mTOR inhibitors may offer a cardioprotective effect. Experimental evidence for delayed progression of atherosclerosis is consistent with evidence from heart transplantation that coronary artery intimal thickening and the incidence of cardiac allograft vasculopathy are reduced with everolimus versus cyclosporine therapy. Preliminary data also indicate that mTOR inhibitors may improve arterial stiffness, a predictor of cardiovascular events, and may reduce ventricular remodeling and decrease left ventricular mass through an anti-fibrotic effect. Post-transplant dyslipidemia under mTOR inhibitor therapy should be monitored and managed closely, but unless unresponsive to therapy should not be regarded as a barrier to its use.

Cardiovascular morbidity and mortality after kidney transplantation

Kidney transplantation is the optimal treatment for patients with end stage renal disease (ESRD) who would otherwise require dialysis. Patients with ESRD are at dramatically increased cardiovascular (CV) risk compared with the general population. As well as improving quality of life, successful transplantation accords major benefits by reducing CV risk in these patients. Worldwide, cardiovascular disease remains the leading cause of death with a functioning graft and therefore is a leading cause of graft failure. This review focuses on the mechanisms underpinning excess CV morbidity and mortality and current evidence for improving CV risk in kidney transplant recipients. Conventional CV risk factors such as hypertension, diabetes mellitus, dyslipidaemia and pre-existing ischaemic heart disease are all highly prevalent in this group. In addition, kidney transplant recipients exhibit a number of risk factors associated with pre-existing renal disease. Furthermore, complications specific to transplantation may ensue including reduced graft function, side effects of immunosuppression and post-transplantation diabetes mellitus. Strategies to improve CV outcomes post-transplantation may include pharmacological intervention including lipid-lowering or antihypertensive therapy, optimization of graft function, lifestyle intervention and personalizing immunosuppression to the individual patients risk profile.

Microarray analysis of long non-coding RNA expression in human acute rejection biopsy samples following renal transplantation

Rejection is still a major obstacle in long-term allograft survival of renal transplant recipients. Long non‑coding RNAs (lncRNAs) are an important class of pervasive RNAs involved in a variety of biological functions, and which are often found to be differentially expressed between healthy and pathological conditions. The aim of this study was to compare the expression profiles of lncRNAs between samples from acute rejection following kidney transplantation and control samples. Three patients were enrolled, diagnosed by renal biopsy with acute rejection upon kidney transplantation. We used lncRNA microarrays to study the lncRNA expression profiles in the kidney biopsies of these patients and in kidneys from healthy donors. Reverse transcription‑quantitative polymerase chain reaction (RT-qPCR) was used to validate the microarray results. In addition, potential functions of the identified lncRNAs were further explored by searching the UCSC, RNAdb, RefSeq and NRED databases. Five candidate lncRNAs displaying differential expression in acute rejection samples were validated by RT-qPCR. The results were in agreement with the microarray data. Among the identified lncRNAs, certain have been previously identified in relevant conditions, thereby supporting previous evidence, but certain may constitute novel biomarker candidates. This is the first report to date using lncRNA microarrays to identify unique expression signatures of acute rejection in transplant biopsies. Our data indicate that lncRNAs are potentially involved in the pathogenesis of acute rejection. Our results may have important implications in the identification of diagnostic biomarkers, as well as in the understanding and treatment of acute rejection following renal transplantation.

Impact of the reduction of calcineurin inhibitors on renal function in heart transplant patients: a systematic review and meta-analysis

AIMS

Calcineurin inhibitors (CNIs) taken after heart transplantation lead to excellent short-term outcomes, but long-term use may cause chronic nephrotoxicity. Our aim was to identify, appraise, select and analyse all high-quality research evidence relevant to the question of the clinical impact of CNI-sparing strategies in heart transplant patients.

METHODS

We carried out a systematic review and meta-analysis of randomized controlled trials on CNI reduction in heart transplant recipients. Primary outcomes were kidney function and acute rejection after 1 year. Secondary outcomes included graft loss, all-cause mortality and adverse events.

RESULTS

Eight open-label studies were included, with 723 patients (four tested de novo CNI reduction and four maintenance CNI reduction). Calcineurin inhibitor reduction did not improve creatinine clearance at 12 months 5.46 [-1.17, 12.03] P = 0.32 I(2)  = 65.4%. Acute rejection at 12 months (55/360 vs. 52/332), mortality (18/301 vs. 15/270) and adverse event rates (55/294 vs. 52/281) did not differ between the low-CNI and standard-CNI groups. There was significant benefit on creatinine clearance in patients with impaired renal function at 6 months [+12.23 (+5.26, +18.82) ml min(-1) , P = 0.0003] and at 12 months 4.63 [-4.55, 13.82] P = 0.32 I(2)  = 75%.

CONCLUSIONS

This meta-analysis did not demonstrate a favourable effect of CNI reduction on kidney function, but there was no increase in acute rejection. To provide a better analysis of the influence of CNI reduction patterns and associated treatments, a meta-analysis of individual patient data should be performed.

mTOR inhibitors in pediatric kidney transplantation

The mammalian target of the rapamycin (mTOR) inhibitors sirolimus and everolimus are increasingly being used in pediatric kidney transplantation in different combinations and doses. Several studies have shown beneficial effects of using mTOR inhibitors in children after pediatric renal transplantation. A switch to a low-dose calcineurin inhibitor (CNI) and mTOR inhibitor has been proven to stabilize the glomerular filtration rate. Additionally, de novo studies using a low-dose CNI and an mTOR inhibitor have shown good graft survival and a low number of rejections. Side effects of mTOR inhibitors, such as hyperlipidemia, wound healing problems, and proteinuria, mainly occur if high doses are given and if treatment is not combined with a CNI. Lower doses of mTOR inhibitors do not result in growth impairment or reduced testosterone levels. Treatment with mTOR inhibitors is also associated with a lower number of viral infections, especially cytomegalovirus. Due to their antiproliferative effect, mTOR inhibitors could theoretically reduce the risk of post-transplant lymphoproliferative disease. mTOR inhibitors, especially in combination with low-dose CNIs, can safely be used in children after kidney transplantation as de novo therapy or for conversion from CNI- and mycophenolate mofetil-based regimens.

Intensified pharmaceutical care is improving immunosuppressive medication adherence in kidney transplant recipients during the first post-transplant year: a quasi-experimental study

BACKGROUND

Medication adherence is critical for transplant patients because the consequences of non-adherence can result in allograft loss and may be life threatening.

METHODS

A prospective study with 74 renal transplant recipients using a sequential control group design was performed to investigate the impact of a pharmaceutical intensified care programme led by a clinical pharmacist on daily drug adherence during the first year after renal transplantation. Thirty-nine patients of the control group received the already established standardized drug and transplant training, while 35 patients of the intensified care group (ICG) received additional inpatient and outpatient pharmaceutical care and counselling by a dedicated clinical pharmacist. Applied interventions were clustered and classified using the behaviour change technique taxonomy according to Michie. Adherence to immunosuppressive drug therapy was monitored up to 1 year using a medication event monitoring system, pill count (PC), drug holiday (DH) occurrence, Morisky questionnaire and self-report.

RESULTS

Sixty-seven patients (35 of the standard care and 32 of the ICG) were analysed. Implementation of DA was significantly (P = 0.014) improved in patients of the ICG (91%) compared with SCG (75%) during the first year after transplantion. Daily adherence measures were already improved within 30-40 days after start of intensified patient care and continued throughout the study period. Intensified care patients also showed significantly better results for taking adherence (P = 0.006), PC (P = 0.008) and DHs (P = 0.001).

CONCLUSIONS

The additional, intensified pharmaceutical care improved patients' medication adherence remarkably, suggesting that the applied additional care programme has the potential to improve outcomes after organ transplantation.

Long-term follow-up of a phase III clinical trial comparing tacrolimus extended-release/MMF, tacrolimus/MMF, and cyclosporine/MMF in de novo kidney transplant recipients

Background

In a phase III, open-label, comparative, noninferiority study, 638 subjects receiving de novo kidney transplants were randomized to one of three treatment arms: tacrolimus extended-release (Astagraf XL) qd, tacrolimus (Prograf) bid, or cyclosporine (CsA) bid. All subjects received basiliximab induction, mycophenolate mofetil, and corticosteroids. Safety and efficacy follow-up data through 4 years are reported.

Methods

Evaluations included patient and graft survival, study drug discontinuations, laboratory values including renal function and development of new-onset diabetes after transplantation, concomitant medications, and adverse events.

Results

At study termination, 129 Astagraf XL, 113 Prograf, and 79 CsA patients had continued follow-up. Demographic and baseline characteristics were similar in all arms. Four-year Kaplan-Meier estimates of patient survival in the Astagraf XL, Prograf, and CsA groups were 93.2, 91.2, and 91.7%, respectively, while graft survival was 84.7, 82.7, and 83.9%, respectively. At least one serious adverse event was reported in the majority of patients in each group during the study (65.9% Astagraf XL, 69.8% Prograf, and 65.6% CsA). Renal function was not significantly different between Astagraf XL and Prograf. HgbA1c levels were collected every 6 months; the 4-year Kaplan-Meier estimate for incidence of HgbA1c levels ≥6.5% was significantly higher for both tacrolimus formulations compared to CsA; 41.1% (Astagraf XL), 33.6% (Prograf), and 21.3% (CsA).

Conclusions

In this 4-year follow-up report, patients receiving Astagraf XL and Prograf showed comparable efficacy and safety profiles, with a higher incidence of new-onset diabetes after transplantation but superior renal function compared to patients receiving CsA.

High impact of rejection therapy on the incidence of post-transplant diabetes mellitus after kidney transplantation

BACKGROUND

Although major risk factors for post-transplant diabetes (PTDM) after kidney transplantation have been identified, a systematic study on the impact of rejection and rejection therapy is missing so far.

METHODS

Five hundred and twenty-six kidney transplant recipients transplanted in the years 2000-2007 were included. PTDM was defined according to WHO guidelines, and patients' data were compared with special attention to protocol and for cause biopsies and rejection therapies. Survival analyses were made for graft loss and patient death.

RESULTS

16.7% of all patients developed PTDM. Among common risk factors as higher age, body mass index (BMI), and others, the factor "acute cellular rejections" was comparably most relevant with a hazard ratio of 3.7. Consequently, antirejective treatment with steroid pulses and conversion to tacrolimus was the factor with the highest relative risk for the onset of PTDM (RR 3.5). PTDM itself had no impact on graft or patients' survival, but the decreased graft survival in PTDM patients was dominantly influenced by the higher frequency of acute cellular rejections, and patients' survival was reduced due to higher age.

CONCLUSION

Based upon a higher rate of acute rejections (AR), the necessity of frequent antirejective treatments was more relevant for the induction of PTDM than age or BMI.

Calcineurin inhibitors: 40 years later, can't live without

Calcineurin inhibitors (CNIs) revolutionized the field of organ transplantation and remain the standard of care 40 years after the discovery of cyclosporine. The early impressive results of cyclosporine in kidney transplant recipients led to its subsequent use in other organ transplant recipients and for treatment of a variety of autoimmune diseases as well. In this review, we examine the discovery of CNIs, their mechanism of action, preclinical and clinical studies with CNIs, and the usage of CNIs in nontransplant recipients. We review the mechanisms of renal toxicity associated with CNIs and the recent efforts to avoid or reduce usage of these drugs. Although minimization strategies are possible, safe, and of potential long-term benefit, complete avoidance of CNIs has proven to be more challenging than initially thought.

Ten years experience with belatacept-based immunosuppression after kidney transplantation

Background

Belatacept was approved for prevention of acute rejection in adult kidney transplantation in 2011 based on two randomized, controlled, multicenter phase 3 studies. Long-term experience over 10 years with belatacept-based immunosuppression after kidney transplantation has not been reported before.

Patients and Methods

Analyzed were 20 patients who had been included into a randomized multicenter phase 2 study by our institution between March 2001 and November 2002. For 10-year follow-up, three different groups could be analyzed: 1) patients with primary calcineurin inhibitor-based (CNI-based) immunosuppression (n = 5), 2) patients with early switch from a belatacept-based to a CNI-based regimen within the first 14 months (n = 8) and 3) patients with completely CNI-free belatacept immunosuppression (n = 7).

Results

Fifteen patients received primary belatacept-based immunosuppression and five patients primary cyclosporine A (CyA). Five patients are still on belatacept. Kidney function measured by serum creatinine levels worsened in the CNI group and the belatacept to CNI switch group during long-term follow-up whereas all patients receiving belatacept throughout follow-up showed stable creatinine values. Acute rejections occurred predominantly in the first 12 months after transplantation and were responsible for four of seven switches from belatacept- to CNI-based immunosuppression within the first 14 months. Five of the 20 patients died.

Conclusions

Belatacept is effective and safe in renal transplant patients and was not associated with graft loss due to chronic allograft nephropathy. Belatacept was well tolerated in all patients and caused less nephrotoxic side effects and was well accepted in most patients.

The allo- and viral-specific immunosuppressive effect of belatacept, but not tacrolimus, attenuates with progressive T cell maturation

Tacrolimus impairs allo- and viral-specific T cell responses. Belatacept, a costimulation-based alternative to tacrolimus, has emerged with a paradoxical picture of less complete control of alloimmunity with concomitant impaired viral immunity limited to viral-naïve patients. To reconcile these signatures, bulk population and purified memory and naïve lymphocytes from cytomegalovirus (CMV)-seropositive (n=10) and CMV-seronegative (n=10) volunteers were studied using flow cytometry, interrogating proliferation (carboxyfluorescein succinimidyl ester dilution) and function (intracellular cytokine staining) in response to alloantigens or CMV-pp-65 peptides. As anticipated, T cells from CMV-experienced, but not naïve, individuals responded to pp-65 with a small percentage of their repertoire (<2.5%) consisting predominantly of mature, polyfunctional (expressing interferon gamma, tumor necrosis factor alpha and IL-2) T effector memory cells. Both CMV naïve and experienced individuals responded similarly to alloantigen with a substantially larger percentage of the repertoire (up to 48.2%) containing proportionately fewer polyfunctional cells. Tacrolimus completely inhibited responses of CMV- and allo-specific T cells regardless of their maturation. However, belatacept's effects were decreasingly evident in increasingly matured cells, with minimal effect on viral-specific triple cytokine producers and CD28-negative allo-specific cells. These data indicate that belatacept's immunosuppressive effect, unlike tacrolimus's, wanes on progressively developed effector responses, and may explain the observed clinical effects of belatacept.

Conversion to mTOR-inhibitor-based immunosuppression: which patients and when?

Mammalian target of rapamycin (mTOR) inhibitors are currently considered an alternative immunosuppressive treatment that can prevent the nephrotoxicity, viral infections and malignancies that are associated with calcineurin inhibitor-based immunosuppressive regimens. However, the side effects of mTOR-inhibitor-based regimens lead to frequent treatment discontinuations, and not all patients seem to have the same benefits from conversion to mTOR inhibitors. This review focuses on long-term results of trials that have assessed early and late conversion to sirolimus or everolimus. The renal benefit of late conversion (≥1 year post transplantation) is limited, except in patients with good renal function and without proteinuria. Early conversion to mTOR inhibitors in the first 6 months, in combination with mycophenolate mofetil, could be an appropriate strategy for maintenance therapy in renal transplant recipients with a low immunological risk after careful screening at the time of conversion. Good renal function (glomerular filtration rate >40 ml/ minute), weak proteinuria (<1 g/day), an absence of previous acute rejection and subclinical rejection, and appearance of donor-specific anti-human leukocyte antigen antibodies appear to be the most important criteria in identifying patients for whom conversion to an mTOR inhibitor may improve renal function at 5 years.

Optimising the use of mTOR inhibitors in renal transplantation

Renal transplantation is the treatment of choice for end-stage renal failure. Although advances in immunosuppression have led to improvements in short-term outcomes, graft survival beyond 5 to 10 years has not improved. One of the major causes of late renal allograft failure is chronic allograft nephropathy, a component of which is nephrotoxicity from the use of calcineurin inhibitors (CNIs). In addition, premature patient death is a major limitation of renal transplantation and the major causes are cancer, cardiovascular disease and infection. CNI-free immunosuppressive regimens based on mammalian target of rapamycin (mTOR) inhibitors have been trial led over the last few years and have defined the rational use of these agents. Conversion from a CNI-based to an mTOR-inhibitor-based regimen has been successful at improving renal function for a number of years after conversion, although long-term survival outcomes are still awaited. The studies suggest that the safest and most effective time to convert is between 1 and 6 months after transplant. In addition, mTOR-inhibitor-based regimens have been shown to be associated with lower rates of post-transplant malignancy and less cytomegalovirus infection, which may add further to the appeal of this approach.

Growing experience with mTOR inhibitors in pediatric solid organ transplantation

Controlled trials of mTOR inhibitors in children following solid organ transplantation are scarce, although evidence from prospective single-arm studies is growing. Everolimus with reduced CNI therapy has been shown to be efficacious and safe in de novo pediatric kidney transplant patients in prospective trials. Prospective and retrospective data in children converted from CNI therapy to mTOR inhibition following kidney, liver, or heart transplantation suggest preservation of immunosuppressive efficacy. Good renal function has been maintained when mTOR inhibitors are used de novo in children following kidney transplantation or after conversion to mTOR inhibition with CNI minimization. mTOR inhibition with reduced CNI exposure is associated with a low risk for developing infection in children. Growth and development do not appear to be impaired during low-dose mTOR inhibition, but more studies are required. No firm conclusions can be drawn as to whether mTOR inhibitors should be discontinued in children requiring surgical intervention or whether mTOR inhibition delays progression of hepatic fibrosis after pediatric liver transplantation. In conclusion, current evidence suggests that use of mTOR inhibitors in children undergoing solid organ transplantation is efficacious and safe, but a number of issues remain unresolved and further studies are required.

Safety of immunosuppressive drugs used as maintenance therapy in kidney transplantation: a systematic review and meta-analysis

To evaluate the safety of regimens containing calcineurin inhibitors (CNI), proliferation signal inhibitors (TOR-I) and antimetabolites, we conducted a meta-analysis of randomized clinical trials (RCTs) and observational studies. A total of 4,960 citations were identified in our electronic search and 14 additional articles were identified through hand searching. Forty-eight articles (11,432 participants) from 42 studies (38 RCTs and four cohorts) met the inclusion criteria. Meta-analysis results revealed the following: (i) tacrolimus was associated with an increased risk for diabetes and lower risk of dyslipidemia, compared to cyclosporine; (ii) mycophenolate mofetil (MMF) was associated with increased risk for total infections, abdominal pain, diarrhea and vomiting, compared with azathioprine; (iii) sirolimus was associated with higher risk of anemia, diabetes, dyslipidemia, lymphoceles and withdrawal compared to tacrolimus or cyclosporine, and cyclosporine was associated with an increased risk of CMV infection; (iv) the combination of CNI with antimetabolites was associated with more adverse events than CNI alone; (v) TOR-I was related to more adverse events than MMF. The data observed in this meta-analysis are similar to those describe by others authors; thus, the choice of treatment must be made by the clinical staff based on specific patient characteristics.

[Tumor and transplantation]

Tumor treatment and transplantation-associated with unavoidable mandatory immunosuppression-appear to be unreconcilable opposites. The clinical reality shows, however, that transplantation in many early stage primary tumors is the most effective treatment. The essential immunosuppression after transplantation can however promote tumor recurrence. Immunosuppression also leads to a significant increased rate of de novo tumors-in all organ transplant recipients. However, not all immunosuppressant drugs have the same effect on tumors. In experimental and clinical settings, the class of mTOR inhibitors has a clear antitumoral effect and is recommended as the immunosuppression treatment of choice in patients with increased tumor risk. The purpose of this review is to provide the reader with the scientific background regarding the clinical problem of tumors and transplantation.

Is it time to give up with calcineurin inhibitors in kidney transplantation?

Calcineurin inhibitors (CNIs) represent today a cornerstone for the maintenance immunosuppressive treatment in solid organ transplantation. Nevertheless, several attempts have been made either to minimize their dosage or to avoid CNIs at all because these drugs have the severe side effect of chronic nephrotoxicity. This issue represents a frontier for renal transplantation. The principal problem is to understanding whether the poor outcome over the long-term may be ascribed to CNIs nephrotoxicity or to the inability of these drugs to control the acute and chronic rejection B cells mediated. The authors analyze extensively all the international trials attempting to withdraw, minimize or avoid the use of CNIs. Few trials undertaken in low risk patients with an early conversion from CNIs to proliferation signal inhibitors were successful, but the vast majority of trials failed to improve CNIs side effects. To date the use of a new drug, a co-stimulation blocker, seems promising in avoiding CNIs with similar efficacy, better glomerular filtration rate and an improved metabolic profile. Moreover the use of this drug is not associated with the development of donor-specific anti-human leukocyte antigen antibodies. This point has a particular relevance, because the failure of CNIs to realize good outcomes in renal transplantation has recently ascribed to their inability to control the acute and chronic rejections B-cell mediated. This paper analyzes all the recent studies that have been done on this issue that represents the real frontier that should be overcome to realize better results over the long-term after transplantation.

Current trends in immunosuppressive therapies for renal transplant recipients

PURPOSE

Current trends in immunosuppressive therapies for renal transplant recipients are reviewed.

SUMMARY

The common premise for immunosuppressive therapies in renal transplantation is to use multiple agents to work on different immunologic targets. The use of a multidrug regimen allows for pharmacologic activity at several key steps in the T-cell replication process and lower dosages of each individual agent, thereby producing fewer drug-related toxicities. In general, there are three stages of clinical immunosuppression: induction therapy, maintenance therapy, and treatment of an established acute rejection episode. Only immunosuppressive therapies used for maintenance therapy are discussed in detail in this review. The most common maintenance immunosuppressive agents can be divided into five classes: (1) the calcineurin inhibitors (CNIs) (cyclosporine and tacrolimus), (2) costimulation blockers (belatacept), (3) mammalian target of rapamycin inhibitors (sirolimus and everolimus), (4) antiproliferatives (azathioprine and mycophenolic acid derivatives), and (5) corticosteroids. Immunosuppressive regimens vary among transplantation centers but most often include a CNI and an adjuvant agent, with or without corticosteroids. Selection of appropriate immunosuppressive regimens should be patient specific, taking into account the medications' pharmacologic properties, adverse-event profile, and potential drug-drug interactions, as well as the patient's preexisting diseases, risk of rejection, and medication regimen.

CONCLUSION

Advancements in transplant immunosuppression have resulted in a significant reduction in acute cellular rejection and a modest increase in long-term patient and graft survival. Because the optimal immunosuppression regimen is still unknown, immunosuppressant use should be influenced by institutional preference and tailored to the immunologic risk of the patient and adverse-effect profile of the drug.

Identification and characterization of kidney transplants with good glomerular filtration rate at 1 year but subsequent progressive loss of renal function

BACKGROUND

After the first year after kidney transplantation, 3% to 5% of grafts fail each year but detailed studies of how grafts progress to failure are lacking. This study aimed to analyze the functional stability of kidney transplants between 1 and 5 years after transplantation and to identify initially well-functioning grafts with progressive decline in allograft function.

METHODS

The study included 788 adult conventional kidney transplants performed at the Mayo Clinic Rochester between January 2000 and December 2005 with a minimum graft survival and follow-up of 2.6 years. The modification of diet in renal disease equation for estimating glomerular filtration rate (eGFR(MDRD)) was used to calculate the slope of renal function over time using all available serum creatinine values between 1 and 5 years after transplantation.

RESULTS

Most transplants demonstrated good function (eGFR(MDRD) ≥40 mL/min) at 1 year with positive eGFR(MDRD) slope between 1 and 5 years after transplantation. However, a subset of grafts with 1-year eGFR(MDRD) ≥40 mL/min exhibited strongly negative eGFR(MDRD) slope between 1 and 5 years suggestive of progressive loss of graft function. Forty-one percent of this subset reached graft failure during follow-up, accounting for 69% of allograft failures occurring after 2.5 years after transplantation. This pattern of progressive decline in estimated glomerular filtration rate despite good early function was associated with but not fully attributable to factors suggestive of enhanced antidonor immunity.

CONCLUSIONS

Longitudinal analysis of serial estimated glomerular filtration ratemeasurements identifies initially well-functioning kidney transplants at high risk for subsequent graft loss. For this subset, further studies are needed to identify modifiable causes of functional decline.

Inhibitors of mTOR and risks of allograft failure and mortality in kidney transplantation

Data on long-term outcomes of users of inhibitors of the mammalian target of rapamycin (mTORI) are lacking in kidney transplantation. In an analysis of 139 370 US kidney transplant recipients between 1999 through 2010, we compared clinical outcomes among users of mTORIs versus calcineurin inhibitors (CNI) in their primary immunosuppresive regimen. During the first 2 years posttransplantation, primary use of mTORIs without CNIs (N = 3237) was associated with greater risks of allograft failure and death compared with a CNI-based regimen (N = 125 623); the hazard ratio (HR) of the composite outcome ranged from 3.67 (95% confidence interval [CI], 3.12-4.32) after discharge to 1.40 (95% CI 1.26-1.57) by year 2. During years 2-8, primary use of mTORIs without CNIs was independently associated with greater risks of death (HR 1.25; 95% CI, 1.11-1.41) and the composite (HR 1.17; 95%CI, 1.08-1.27) in fully adjusted analyses. The results were qualitatively unchanged in subgroups defined by medical history, immunological risk and clinical course during the index transplant hospitalization. In a propensity-score matched cohort, use of mTORIs was associated with significantly worse outcomes during the first 2 years and greater risks of death (HR 1.21; 95% CI, 1.05-1.39) and the composite (HR 1.18; 95% CI, 1.08-1.30) in years 2-8. Compared with CNI-based regimens, use of an mTORI-based regimen for primary immunosuppression in kidney transplantation was associated with inferior recipient survival.

Impact of the early reduction of cyclosporine on renal function in heart transplant patients: a French randomised controlled trial

BACKGROUND

Using reduced doses of Cyclosporine A immediately after heart transplantation in clinical trials may suggest benefits for renal function by reducing serum creatinine levels without a significant change in clinical endpoints. However, these trials were not sufficiently powered to prove clinical outcomes.

METHODS

In a prospective, multicentre, open-label, parallel-group controlled trial, 95 patients aged 18 to 65 years old, undergoing de novo heart transplantation were centrally randomised to receive either a low (130 < trough CsA concentrations <200 μg/L, n = 47) or a standard dose of Cyclosporine A (200 < trough CsA concentrations <300 μg/L, n = 48) for the three first post-transplant months along with mycophenolate mofetil and corticosteroids. Participants had a stable haemodynamic status, a serum creatinine level <250 μmol/L and the donors' cold ischemia time was under six hours; multiorgan transplants were excluded. The change in serum creatinine level over 12 months was used as the main criterion for renal function. Intention-to-treat analysis was performed on the 95 randomised patients and a mixed generalised linear model of covariance was applied.

RESULTS

At 12 months, the mean (± SD) creatinine value was 120.7 μmol/L (± 35.8) in the low-dose group and 132.3 μmol/L (± 49.1) in the standard-dose group (P = 0.162). Post hoc analyses suggested that patients with higher creatinine levels at baseline benefited significantly from the lower Cyclosporine A target. The number of patients with at least one rejection episode was not significantly different but one patient in the low-dose group and six in the standard-dose group required dialysis.

CONCLUSIONS

In patients with de novo cardiac transplantation, early Cyclosporine A dose reduction was not associated with renal benefit at 12 months. However, the strategy may benefit patients with high creatinine levels before transplantation.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00159159.

An evaluation of sirolimus in renal transplantation

INTRODUCTION

Sirolimus is a powerful antiproliferative immunosuppressive drug approved for the prevention of kidney allograft rejection. By its unique mechanism of action, sirolimus provides a multitude of clinical potential and has been used effectively in different drug combinations. Extensive experience has been gained regarding the best timing of its application, side effect profile and potential benefits and limitations compared with other immunosuppressive drugs.

AREAS COVERED

The authors evaluate the recent experience with sirolimus in kidney transplantation. Pivotal randomized controlled trials were used to provide an overview with special attention to pharmacokinetic and dynamic aspects of sirolimus, its current clinical use as well as perspectives for its future role.

EXPERT OPINION

Sirolimus enriches the possibilities of immunosuppressive therapies after renal transplantation. Beneficial effects toward kidney function by allowing CNI sparing, lower incidence of malignancies and less viral infections have been suggested. Sirolimus should be used cautiously in de novo patients for reasons of wound healing. An early conversion to a sirolimus-based CNI-free regimen has shown promising results, whereas late conversion is more challenging. Finally, sirolimus-associated side effects are causing tolerability concerns and frequent discontinuations. Future research should aim to better define the therapeutic window and those patients most likely to benefit.

Using donor-specific antibodies to monitor the need for immunosuppression

BACKGROUND

Experience with tolerance protocols has shown that none is perfect and that each escape from tolerance must be identified early to prevent graft failure. In addition, some test is needed for patients who are weaned off immunosuppression (IS) to forewarn of weaning failure. The usual measures of function--such as serum creatinine levels--are not sensitive enough to detect rejection in a timely manner.

METHODS

A study was carried out on 72 patients who received living-donor kidney transplants with clonal deletion protocol (total lymphoid irradiation or bortezomib), and followed with reduced doses of maintenance IS. Every month or every 2 months, a test was performed for donor-specific antibodies (DSA) using Luminex mixed and/or single antigen beads.

RESULTS

After transplantation, DSA developed in 17% of the patients at 6 months, 41% at 1 year, and 57% at 2 years, with 95% confidence limits of 10%, 28%; 30%, 55%; and 44%, 71%, respectively. Fifty-three percent of patients weaned IS to less than 10 mg prednisone daily experienced DSA within 3 months. Furthermore, prednisone dose (per 2.5 mg) and years after transplantation were inversely associated with DSA production (risk ratio 0.92 [95% confidence limits: 0.85, 0.99], and 0.70 [0.49, 1.00]).

CONCLUSIONS

DSA monitoring is highly effective for detecting escape from tolerance and reemergence of the immune response in weaned patients. DSA appearance was inversely proportional to the level of maintenance drugs in the weaning process. Measurement of DSA on a monthly basis is adequate for detection of the change in immune reactivity.

Does reduction in mycophenolic acid dose compromise efficacy regardless of tacrolimus exposure level? An analysis of prospective data from the Mycophenolic Renal Transplant (MORE) Registry

Prospective data are lacking concerning the effect of reduced mycophenolic acid (MPA) dosing on efficacy and the influence of concomitant tacrolimus exposure. The Mycophenolic Renal Transplant (MORE) Registry is a prospective, observational study of de novo kidney transplant patients receiving MPA therapy under routine management. The effect of MPA dose reduction, interruption, or discontinuation (dose changes) was assessed in 870 tacrolimus-treated patients: 375 (43.1%) reduced tacrolimus (≤7 ng/mL at baseline) and 495 (56.9%) standard tacrolimus (>7 ng/mL); enteric-coated mycophenolate sodium 589 (67.7%) and mycophenolate mofetil 281 (32.3%). During baseline to month 1, months 1–3, months 3–6, and months 6–12, 9.3% (78/838), 16.6% (132/794), 20.7% (145/701), and 13.1% (70/535) patients, respectively, required MPA dose changes. These patients experienced an increased risk of biopsy-proven acute rejection at one yr with tacrolimus exposure either included in the model (hazard ratio [HR] 2.60, 95% CI 1.28–5.29, p = 0.008) or excluded (HR 2.58, 95% CI 1.28–5.23, p = 0.008). MPA dose changes were significantly associated with one yr graft failure when tacrolimus exposure was included (HR 2.23; 95% CI 1.01–4.89, p = 0.047) but not when tacrolimus exposure was excluded (HR 2.16; 95% CI 0.99–4.79; p = 0.054). These results suggest that reducing or discontinuing MPA can adversely affect graft outcomes regardless of tacrolimus trough levels.

Dyslipidemia and its therapeutic challenges in renal transplantation

Cardiovascular disease is the leading cause of mortality in kidney transplant recipients. Dyslipidemia is a common finding after renal transplantation and a significant risk factor in the development of coronary heart disease. Although a causal relationship with cardiovascular mortality has not been proven in the transplant population, it is reasonable to extrapolate data from the general population and aggressively treat posttransplant dyslipidemia. Statins are considered the agents of choice, though their use may be complicated by drug misadventures. Pravastatin, fluvastatin and pitavastatin are considered to be the safest statins to use in this population; however, given their low-potency, a high-potency statin, such as atorvastatin, may be necessary in patients with significant dyslipidemia. In this article, we discuss the etiology of and treatment strategies for dyslipidemia in renal transplant recipients based on a literature review of potential therapeutic adverse effects and benefits in this population. We will also evaluate the reasons for and consequences of the latest Food and Drug Administration (FDA) warnings regarding the use of simvastatin.

Cyclosporin but not everolimus inhibits chemokine receptor expression on CD4+ T cell subsets circulating in the peripheral blood of renal transplant recipients

The peripheral chemokine receptors chemokine receptor 3 (CXCR3) and CC chemokine receptor 5 (CCR5) have been reported to be associated with allograft rejection. The impact of the expression of immunosuppressive drugs on peripherally circulating CD4(+) T cell subsets after renal transplantation is unknown. Expression of CXCR3 and CCR5 was investigated by flow cytometry in 20 renal allograft recipients participating in a prospective, randomized trial (NCT00514514). Initial immunosuppression consisted of basiliximab, cyclosporin A (CsA), mycophenolate sodium and corticosteroids. After 3 months, patients were treated either with CsA, mycophenolate sodium (MPA) plus corticosteroids (n = 6), CsA and everolimus plus corticosteroids (n =8) or CsA-free (CsA(free)) receiving everolimus, MPA and corticosteroids (n = 6). After initial reduction of CD4(+) forkhead box protein 3 (FoxP3)(+) and CD4(+) CD25(hi) FoxP3(+) regulatory T cells (T(regs)) (P < 0.05; P < 0.01), 3-month post-transplant percentages of T(regs) were reconstituted in CsA(free) and CsA(lo) arms compared to CsA(reg) 12 months post transplant. Expression of CCR5 and CXCR3 on CD4(+) FoxP3(+) and CD4(+) FoxP3(-) T cells 12 months post transplant was increased in CsA(free) versus CsA(reg). Increase in CCR5(+) CXCR3(+) co-expressing CD4(+) FoxP3(-) cells between 3 and 12 months correlated negatively with the glomerular filtration rate (GFR) slope/year [modification of diet in renal disease (MDRD); r = -0.59, P < 0.01]. CsA, but not everolimus, inhibits both T(reg) development and expression of CXCR3 and CCR5 on CD4(+) T cell subsets. Increase in CCR5(+) CXCR3(+) co-expressing CD4(+) FoxP3(-) T cells is associated with early loss in allograft function.

Are calcineurin inhibitors-free regimens ready for prime time?

The goal of research in transplant therapeutics is to achieve safe and effective immunosuppression strategies that allow durable engraftment free of toxicities. The calcineurin inhibitors (CNIs) regimens, because of their inherent toxicities (including nephrotoxicity), have been unable to meet these promises. Over the past decade acute cellular rejection decreased dramatically with a concomitant robust increase in 1-year graft survival; however, long-term graft outcome showed only modest improvement. This is due in part to the toxicities of the immunosuppressive drugs. The quest for a toxicity-free-CNI-free regimen has been both intense and frustrating. A turning point in CNIs-free therapy may have occurred with the recent approval of belatacept, which represents a new paradigm in immunosuppression: biological therapy for chronic immunosuppression devoid of the usual toxicities associated with the CNIs. Belatacept, a fusion receptor protein, blocks costimulation signals necessary for the activation of T cells. Although costimulation blockade has not been shown to induce tolerance, it can provide safe and effective immunosuppression without renal or cardiovascular toxicities. The approval of belatacept in both the United States and Europe for use in renal transplantation will finally push CNI-free regimens into prime time. Novel biologics such as ASKP1240 (a human anti-CD40 monoclonal antibody) and one small molecule, tofacitinib, may advance further the use of CNI-free regimens in organ transplantation.

Genetic and clinical determinants of early, acute calcineurin inhibitor-related nephrotoxicity: results from a kidney transplant consortium

BACKGROUND

Calcineurin inhibitor (CNI)-related acute nephrotoxicity is a common complication of transplantation. Clinical factors and elevated CNI levels are associated with nephrotoxicity; however, they do not fully explain the risk. Genetic factors may also predispose individuals to nephrotoxicity.

METHODS

We enrolled 945 kidney recipients into a multicenter, prospective study. DNA was genotyped for 2724 single-nucleotide polymorphisms (SNPs) using a customized chip. Cox models, unadjusted and adjusted for clinical factors, examined the association between SNPs and time to early CNI-related acute nephrotoxicity in the first 6 months posttransplant.

RESULTS

Cyclosporine was associated with a 1.49 hazard (95% confidence interval, 1.04-2.14) of acute nephrotoxicity relative to tacrolimus. Acute nephrotoxicity occurred in 22.6% of cyclosporine and 19.8% of tacrolimus recipients. The median (interquartile range) daily dose and trough concentration at time of nephrotoxicity were 400 mg (400-500 mg) and 228 ng/mL (190-272 ng/mL) in the cyclosporine group, and 6 mg (4-8 mg) and 12.6 ng/mL (10.2-15.9 ng/mL) in the tacrolimus group, respectively. In single-SNP adjusted analysis, nine SNPs in the XPC, CYP2C9, PAX4, MTRR, and GAN genes were associated with cyclosporine nephrotoxicity. In a multi-SNP analysis, SNPs from the same genes remained significant after adjusting for the clinical factors, showing that the SNPs are jointly and independently predictive of cyclosporine nephrotoxicity. No SNPs were associated with tacrolimus nephrotoxicity.

CONCLUSION

We identified SNPs that were potentially associated with early, acute cyclosporine-related nephrotoxicity. Identifying risk SNPs before transplantation provides an opportunity for personalization of immunosuppression by identifying those who may benefit from CNI-avoidance or minimization, or assist in selecting CNI type. These SNPs require independent validation.

DR(high+)CD45RA(-)-Tregs potentially affect the suppressive activity of the total Treg pool in renal transplant patients

Recent studies show that regulatory T cells (Tregs) play an essential role in tolerance induction after organ transplantation. In order to examine whether there are differences in the composition of the total CD4⁺CD127^low+/−FoxP3⁺- Treg cell pool between stable transplant patients and patients with biopsy proven rejection (BPR), we compared the percentages and the functional activity of the different Treg cell subsets (DR^high+CD45RA⁻-Tregs, DR^low+CD45RA⁻-Tregs, DR⁻CD45RA⁻-Tregs, DR⁻CD45RA⁺-Tregs). All parameters were determined during the three different periods of time after transplantation (0–30 days, 31–1,000 days, >1,000 days). Among 156 transplant patients, 37 patients suffered from BPR. The most prominent differences between rejecting and non-rejecting patients were observed regarding the DR^high+CD45RA⁻-Treg cell subset. Our data demonstrate that the suppressive activity of the total Treg pool strongly depends on the presence of these Treg cells. Their percentage within the total Treg pool strongly decreased after transplantation and remained relatively low during the first year after transplantation in all patients. Subsequently, the proportion of this Treg subset increased again in patients who accepted the transplant and reached a value of healthy non-transplanted subjects. By contrast, in patients with acute kidney rejection, the DR^high+CD45RA⁻-Treg subset disappeared excessively, causing a reduction in the suppressive activity of the total Treg pool. Therefore, both the monitoring of its percentage within the total Treg pool and the monitoring of the HLA-DR MFI of the DR⁺CD45RA⁻-Treg subset may be useful tools for the prediction of graft rejection.

Calcineurin inhibitors in kidney transplantation: friend or foe?

PURPOSE OF REVIEW

The utilization of calcineurin inhibitors (CNI) in kidney transplantation has dramatically improved short-term outcomes but significant gains in long-term outcomes have proved elusive. Nephrotoxicity is the major problem associated with CNIs and is responsible for the disappointing progress seen in long-term graft survival. In this review, we assess CNI efficacy as well as the latest strategies employed to limit long-term CNI nephrotoxicity.

RECENT FINDINGS

Three CNI sparing strategies - CNI withdrawal, CNI avoidance, and CNI minimization - are evaluated with discussion of key studies such as the Efficacy Limiting Toxicity Elimination-Symphony and Spare-the-Nephron studies. Recent breakthroughs in transplant immunosuppression are discussed such as the BENEFIT and BENEFIT-EXT studies, which have led to the recent US Food and Drug Administratrion approval of belatacept, a novel T-cell costimulation blocker.

SUMMARY

For now, CNIs remain the proven standard of care in modern immunosuppression. However, some novel agents may challenge the role CNIs play in kidney transplantation in the very near future.

Three-year outcomes from BENEFIT, a randomized, active-controlled, parallel-group study in adult kidney transplant recipients

The clinical profile of belatacept in kidney transplant recipients was evaluated to determine if earlier results in the BENEFIT study were sustained at 3 years. BENEFIT is a randomized 3 year, phase III study in adults receiving a kidney transplant from a living or standard criteria deceased donor. Patients were randomized to a more (MI) or less intensive (LI) regimen of belatacept, or cyclosporine. 471/666 patients completed ≥3 years of therapy. A total of 92% (MI), 92% (LI), and 89% (cyclosporine) of patients survived with a functioning graft. The mean calculated GFR (cGFR) was ∼21 mL/min/1.73 m(2) higher in the belatacept groups versus cyclosporine at year 3. From month 3 to month 36, the mean cGFR increased in the belatacept groups by +1.0 mL/min/1.73 m(2) /year (MI) and +1.2 mL/min/1.73 m(2) /year (LI) versus a decline of -2.0 mL/min/1.73 m(2) /year (cyclosporine). One cyclosporine-treated patient experienced acute rejection between year 2 and year 3. There were no new safety signals and no new posttransplant lymphoproliferative disorder (PTLD) cases after month 18. Belatacept-treated patients maintained a high rate of patient and graft survival that was comparable to cyclosporine-treated patients, despite an early increased occurrence of acute rejection and PTLD.