The ORION study: comparison of two sirolimus-based regimens versus tacrolimus and mycophenolate mofetil in renal allograft recipients

The "Personalising Actinic Keratosis Treatment for Immunocompromised Patients" (IM-PAKT) Project: An Expert Panel Opinion

Actinic keratosis (AK) is an intraepithelial condition characterized by the development of scaly, erythematous lesions after repeated exposure to ultraviolet radiation. Significant immunosuppression is a risk factor for the development of AK and subsequent lesion progression to squamous cell carcinoma. Immunocompromised patients (ICPs), particularly organ transplant recipients, often have more advanced or complex AK presentations and an increased risk of skin carcinomas versus non-ICPs with AK, making lesions more difficult to treat and resulting in worse treatment outcomes. The recent "Personalising Actinic Keratosis Treatment" (PAKT) consensus reported that delivering patient-centric care may play a role in supporting better clinical outcomes and patient satisfaction with treatments for chronic dermatologic conditions such as AK, which require repeated cycles of treatment. Additionally, currently published guidance and recommendations were considered by the PAKT panel to be overly broad for managing ICPs with their unique and complex needs. Therefore, the "Personalising Actinic Keratosis Treatment for Immunocompromised Patients" (IM-PAKT) panel was established to build upon general recommendations from the PAKT consensus. The panel identified current gaps in guidance for AK care in ICPs, offered practical care approaches based on typical ICP scenarios, and highlighted the need to adapt AK management to optimize care and improve treatment outcomes in ICPs. In particular, dermatologists should establish collaborative and transparent relationships with patients' multidisciplinary teams to enhance overall care for patients' comorbidities: given their increased risk of progression to malignancy, earlier assessments/interventions and frequent follow-ups are vital.The panel also developed a novel "triage" tool outlining effective treatment follow-up and disease surveillance plans tailored to patients' risk profiles, guided by current clinical presentation and relevant medical history. Additionally, we present the panel's expert opinion on three fictional ICP scenarios to explain their decision-making process for assessing and managing typical ICPs that they may encounter in clinical practice.

Immunosuppressive drug combinations after kidney transplantation and post-transplant diabetes: A systematic review and meta-analysis

Post-transplant diabetes mellitus (PTDM) is a frequent complication after kidney transplantation (KT). This systematic review investigated the effect of different immunosuppressive regimens on the risk of PTDM. We performed a systematic literature search in MEDLINE and CENTRAL for randomized controlled trials (RCTs) that included KT recipients with any immunosuppression and reported PTDM outcomes up to 1 October 2023. The analysis included 125 RCTs. We found no differences in PTDM risk within induction therapies. In de novo KT, there was an increased risk of developing PTDM with tacrolimus versus cyclosporin (RR 1.71, 95%CI [1.38-2.11]). No differences were observed between tacrolimus+mammalian target of rapamycin inhibitor (mTORi) and tacrolimus+MMF/MPA, but there was a tendency towards a higher risk of PTDM in the cyclosporin+mTORi group (RR 1.42, 95%CI [0.99-2.04]). Conversion from cyclosporin to an mTORi increased PTDM risk (RR 1.89, 95%CI [1.18-3.03]). De novo belatacept compared with a calcineurin inhibitor resulted in 50% lower risk of PTDM (RR 0.50, 95%CI [0.32-0.79]). Steroid avoidance resulted in 31% lower PTDM risk (RR 0.69, 95%CI [0.57-0.83]), whereas steroid withdrawal resulted in no differences. Immunosuppression should be decided on an individual basis, carefully weighing the risk of future PTDM and rejection.

A review of landmark studies on maintenance immunosuppressive regimens in kidney transplantation

Immunosuppressive medications play a pivotal role in kidney transplantation, and the calcineurin inhibitors (CNIs), including cyclosporine A (CsA) and tacrolimus (TAC), are considered as the backbone of maintenance immunosuppressive regimens. Since the introduction of CNIs in kidney transplantation, the incidence of acute rejection has decreased, and allograft survival has improved significantly. However, CNI nephrotoxicity has been a major concern, believed to heavily impact long-term allograft survival and function. To address this concern, several CNI-sparing regimens were developed and studied in randomized, controlled, clinical trials, aiming to reduce CNI exposure and preserve long-term allograft function. However, more recent information has revealed that CNI nephrotoxicity is not the primary cause of late allograft failure, and its histopathology is neither specific nor pathognomonic. In this review, we discuss the historical development of maintenance immunosuppressive regimens in kidney transplantation, covering the early era of transplantation, the CNI-sparing era, and the current era where the alloimmune response, rather than CNI nephrotoxicity, appears to be the major contributor to late allograft failure. Our goal is to provide a chronological overview of the development of maintenance immunosuppressive regimens and summarize the most recent information for clinicians caring for kidney transplant recipients (KTRs).

Correlations between serum kidney injury molecule-1, cystatin C and immunosuppressants: A cross-sectional study of renal transplant patients in Bahrain

Renal transplant patients receive several immunosuppressive drug regimens that are potentially nephrotoxic for treatment. Serum creatinine is the standard for monitoring kidney function; however, cystatin C (Cys C) and kidney injury molecule-1 (KIM-1) have been found to indicate kidney injury earlier than serum creatinine and provide a better reflection of kidney function. Here, we assessed Cys C and KIM-1 serum levels in renal transplant patients receiving mycophenolate mofetil, tacrolimus, sirolimus, everolimus, or cyclosporine to evaluate kidney function. We used both the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) 2021 equation, which is based on creatinine and combined creatinine with Cys C, and the CKD-EPI 2012 equation, which is based on Cys C alone, to estimate glomerular filtration rate (GFR). Then, we assessed the association between serum KIM-1 and GFR < 90 mL per minute per 1.73 m 2. We observed significantly higher serum Cys C levels in patients with the elevated serum creatinine, compared with those with normal serum creatinine. The estimated GFRs based on creatinine were significantly higher than those based on the other equations, while a significant positive correlation was observed among all equations. Serum KIM-1 levels were negatively correlated with the estimated GFRs by the CKD-EPI Cys C and the combined creatinine with Cys C equations. A serum KIM-1 level above 0.71 ng/mL is likely to indicate GFR < 90 mL per minute per 1.73 m 2. We observed a significant correlation between serum creatinine and Cys C in our renal transplant patients. Therefore, serum KIM-1 may be used to monitor renal function when using potentially nephrotoxic drugs in renal transplants.

Cellular Immunobiology and Molecular Mechanisms in Alloimmunity-Pathways of Immunosuppression

Current maintenance immunosuppression commonly comprises a synergistic combination of tacrolimus as calcineurin inhibitor (CNI), mycophenolic acid, and glucocorticoids. Therapy is often individualized by steroid withdrawal or addition of belatacept or inhibitors of the mechanistic target of rapamycin. This review provides a comprehensive overview of their mode of action, focusing on the cellular immune system. The main pharmacological action of CNIs is suppression of the interleukin-2 pathway that leads to inhibition of T cell activation. Mycophenolic acid inhibits the purine pathway and subsequently diminishes T and B cell proliferation but also exerts a variety of effects on almost all immune cells, including inhibition of plasma cell activity. Glucocorticoids exert complex regulation via genomic and nongenomic mechanisms, acting mainly by downregulating proinflammatory cytokine signatures and cell signaling. Belatacept is potent in inhibiting B/T cell interaction, preventing formation of antibodies; however, it lacks the potency of CNIs in preventing T cell-mediated rejections. Mechanistic target of rapamycin inhibitors have strong antiproliferative activity on all cell types interfering with multiple metabolic pathways, partly explaining poor tolerability, whereas their superior effector T cell function might explain their benefits in the case of viral infections. Over the past decades, clinical and experimental studies provided a good overview on the underlying mechanisms of immunosuppressants. However, more data are needed to delineate the interaction between innate and adaptive immunity to better achieve tolerance and control of rejection. A better and more comprehensive understanding of the mechanistic reasons for failure of immunosuppressants, including individual risk/benefit assessments, may permit improved patient stratification.

mTOR-inhibitors and post-transplant diabetes mellitus: a link still debated in kidney transplantation

The mammalian target of rapamycin inhibitors (mTOR-Is, Sirolimus, and Everolimus) are immunosuppressive drugs widely employed in kidney transplantation. Their main mechanism of action includes the inhibition of a serine/threonine kinase with a pivotal role in cellular metabolism and in various eukaryotic biological functions (including proteins and lipids synthesis, autophagy, cell survival, cytoskeleton organization, lipogenesis, and gluconeogenesis). Moreover, as well described, the inhibition of the mTOR pathway may also contribute to the development of the post-transplant diabetes mellitus (PTDM), a major clinical complication that may dramatically impact allograft survival (by accelerating the development of the chronic allograft damage) and increase the risk of severe systemic comorbidities. Several factors may contribute to this condition, but the reduction of the beta-cell mass, the impairment of the insulin secretion and resistance, and the induction of glucose intolerance may play a pivotal role. However, although the results of several in vitro and in animal models, the real impact of mTOR-Is on PTDM is still debated and the entire biological machinery is poorly recognized. Therefore, to better elucidate the impact of the mTOR-Is on the risk of PTDM in kidney transplant recipients and to potentially uncover future research topics (particularly for the clinical translational research), we decided to review the available literature evidence regarding this important clinical association. In our opinion, based on the published reports, we cannot draw any conclusion and PTDM remains a challenge. However, also in this case, the administration of the lowest possible dose of mTOR-I should also be recommended.

Kidney Disease after Heart and Lung Transplantation

Chronic kidney disease (CKD) is not only common after lung and heart transplantation but also is associated with increased morbidity and mortality due to multiple pre-, peri- and post-transplant factors. While the exact incidence of CKD in this population is not well-defined, it seems to have gradually increased over the years as older recipients are more frequently considered. The increasing success of the procedure and expanding transplant candidate pool has allowed many with comorbid conditions to receive a transplant, which was considered prohibitive in the past. This review presents risk factors that have been linked to CKD as well as interventions that may help alleviate this serious problem. The impact of pretransplant renal function and the overexaggerated role of chronic nephrotoxicity of calcineurin inhibitors is discussed in detail. Until the exact pathophysiology of kidney disease is better understood, there is a dire need to expand the research agenda beyond observational studies.

Tacrolimus before CTLA4Ig and rapamycin promotes vascularized composite allograft survival in MGH miniature swine

BACKGROUND

We evaluated the outcome of vertical rectus abdominus myocutaneous flap (VRAM) allotransplantation in a mini-pig model, using a combined co-stimulation blockade (Co-SB) and mechanistic target of rapamycin inhibition (mTORi)-based regimen, with or without preceding calcineurin inhibition (CNI).

MATERIALS AND METHODS

VRAM allotransplants were performed between SLA-mismatched MGH miniature swine. Group A (n = 2) was treated continuously with the mTOR inhibitor rapamycin from day -1 in combination with the Co-SB agent cytotoxic T lymphocyte antigen 4-Ig (CTLA4-Ig) from post-operative day (POD) 0. In group B (n = 3), animals received tacrolimus daily from POD 0 to POD 13, followed by rapamycin daily from POD 7 and CTLA4-Ig weekly from POD 7-28. Graft rejection was determined by Banff criteria and host cellular and humoral immunity monitored.

RESULTS

In group A, allografts developed grade-I acute rejection by POD 2 and POD 7, and reached grade-IV by POD 17 and POD 20, respectively. By contrast, in group B, two allografts demonstrated grade-I rejection on POD 30 and grade-IV on POD 74, while the third exhibited grade-I rejection starting on POD 50, though this animal had to be euthanized on POD 58 due to Pneumocystis jirovecii infection. Time-to-event incidence of grade-I rejection was significantly lower in group A compared to group B. During the first 3 weeks post-transplant, no significant differences in anti-donor immunity were observed between the groups.

CONCLUSION

A short course of CNI, followed by combined Co-SB and mTORi significantly delays acute rejection of VRAM allografts in SLA-mismatched miniature swine.

A randomized controlled trial to evaluate efficacy and safety of early conversion to a low-dose calcineurin inhibitor combined with sirolimus in renal transplant patients

BACKGROUND

The calcineurin inhibitor (CNI)-based immune maintenance regimen that is commonly used after renal transplantation has greatly improved early graft survival after transplantation; however, the long-term prognosis of grafts has not been significantly improved. The nephrotoxicity of CNI drugs is one of the main risk factors for the poor long-term prognosis of grafts. Sirolimus (SRL) has been employed as an immunosuppressant in clinical practice for over 20 years and has been found to have no nephrotoxic effects on grafts. Presently, the regimen and timing of SRL application after renal transplantation vary, and clinical data are scarce. Multicenter prospective randomized controlled studies are particularly rare. This study aims to investigate the effects of early conversion to a low-dose CNI combined with SRL on the long-term prognosis of renal transplantation.

METHODS

Patients who receive four weeks of a standard regimen with CNI + mycophenolic acid (MPA) + glucocorticoid after renal transplantation in multiple transplant centers across China will be included in this study. At week 5, after the operation, patients in the experimental group will receive an additional administration of SRL, a reduction in the CNI drug doses, withdrawal of MPA medication, and maintenance of glucocorticoids. In addition, patients in the control group will receive the maintained standard of care. The patients' vital signs, routine blood tests, routine urine tests, blood biochemistry, serum creatinine, BK virus (BKV)/ cytomegalovirus (CMV), and trough concentrations of CNI drugs and SRL at the baseline and weeks 12, 24, 36, 48, 72, and 104 after conversion will be recorded. Patient survival, graft survival, and estimated glomerular filtration rate will be calculated, and concomitant medications and adverse events will also be recorded.

CONCLUSION

The study data will be utilized to evaluate the efficacy and safety of early conversion to low-dose CNIs combined with SRL in renal transplant patients.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR1800017277.

Medical Aspects of mTOR Inhibition in Kidney Transplantation

The advances in transplant immunosuppression have reduced substantially the incidence of kidney graft rejection. In recent years, the focus has moved from preventing rejection to preventing the long-term consequences of long-standing immunosuppression, including nephrotoxicity induced by calcineurin inhibitors (CNI), as well as infectious and neoplastic complications. Since the appearance in the late 1990s of mTOR inhibitors (mTORi), these unmet needs in immunosuppression management could be addressed thanks to their benefits (reduced rate of viral infections and cancer). However, management of side effects can be troublesome and hands-on experience is needed. Here, we review all the available information about them. Thanks to all the basic, translational and clinical research achieved in the last twenty years, we now use mTORi as de novo immunosuppression in association with CNI. Another possibility is represented by the conversion of either CNI or mycophenolate (MPA) to an mTORi later on after transplantation in low-risk kidney transplant recipients.

Personalized immunosuppression after kidney transplantation

With advances in immunosuppressive therapy, there have been significant improvements in acute rejection rates and short-term allograft survival in kidney transplant recipients. However, this success has not been translated into long-term benefits by the same magnitude. Optimization of immunosuppression is important to improve the clinical outcome of transplant recipients. It is important to note that each patient has unique attributes and immunosuppression management should not be a one-size-fits-all approach. Elderly transplant patients are less likely to develop acute rejection but more likely to die from infectious and cardiovascular causes than younger patients. For those with post-transplant cancers and BK polyomavirus-associated nephropathy, reduction of immunosuppression can increase the risk of rejection. Therapeutic drug monitoring (TDM) is routinely used for dosage adjustment of several immunosuppressive drugs. It has been hoped that pharmacogenetics can be used to complement TDM in optimizing drug exposure. Among the various drug-genotype pairs being investigated, tacrolimus and CYP3A5 gives the most promising results. Different studies have consistently shown that CYP3A5 expressers require a higher tacrolimus dose and take longer time to achieve target blood tacrolimus levels than nonexpressers. However, for pharmacogenetics to be widely used clinically, further trials are necessary to demonstrate the clinical benefits of genotype-guided dosing such as reduction of rejection and drug-related toxicities. The development of different biomarkers in recent years may help to achieve true personalized therapy in transplant patients.

Mammalian Target of Rapamycin Inhibitors and Wound Healing Complications in Kidney Transplantation: Old Myths and New Realities

Mammalian target of rapamycin inhibitors (mTOR-I) lacks nephrotoxicity, has antineoplastic effects, and reduces viral infections in kidney transplant recipients. Earlier studies reported a significant incidence of wound healing complications and lymphocele. This resulted in the uncomfortable willingness of transplant clinicians to use these agents in the immediate posttransplant period. As evidence and experience evolved over time, much useful information became available about the optimal use of these agents. Understandably, mTOR-I effects wound healing through their antiproliferative properties. However, there are a lot of other immunological and nonimmunological factors which can also contribute to wound healing complications. These risk factors include obesity, uremia, increasing age, diabetes, smoking, alcoholism, and protein-energy malnutrition. Except for age, the rest of all these risk factors are modifiable. At the same time, mycophenolic acid derivatives, steroids, and antithymocyte globulin (ATG) have also been implicated in wound healing complications. A lot has been learnt about the optimal dose of mTOR-I and their trough levels, its combinations with other immunosuppressive medications, and patients' profile, enabling clinicians to use these agents appropriately for maximum benefits. Recent randomized control trials have further increased the confidence of clinicians to use these agents in immediate posttransplant periods.

Long-Term Immunosuppression Management: Opportunities and Uncertainties

The long-term management of maintenance immunosuppression in kidney transplant recipients remains complex. The vast majority of patients are treated with the calcineurin inhibitor tacrolimus as the primary agent in combination with mycophenolate, with or without corticosteroids. A tacrolimus trough target 5-8 ng/ml seems to be optimal for rejection prophylaxis, but long-term tacrolimus-related side effects and nephrotoxicity support the ongoing evaluation of noncalcineurin inhibitor-based regimens. Current alternatives include belatacept or mammalian target of rapamycin inhibitors. For the former, superior kidney function at 7 years post-transplant compared with cyclosporin generated initial enthusiasm, but utilization has been hampered by high initial rejection rates. Mammalian target of rapamycin inhibitors have yielded mixed results as well, with improved kidney function tempered by higher risk of rejection, proteinuria, and adverse effects leading to higher discontinuation rates. Mammalian target of rapamycin inhibitors may play a role in the secondary prevention of squamous cell skin cancer as conversion from a calcineurin inhibitor to an mammalian target of rapamycin inhibitor resulted in a reduction of new lesion development. Early withdrawal of corticosteroids remains an attractive strategy but also is associated with a higher risk of rejection despite no difference in 5-year patient or graft survival. A major barrier to long-term graft survival is chronic alloimmunity, and regardless of agent used, managing the toxicities of immunosuppression against the risk of chronic antibody-mediated rejection remains a fragile balance.

Reducing non-melanoma skin cancer risk in renal transplant recipients

With an increasing number of renal transplant recipients (RTRs) and improving patient survival, a higher incidence of non-melanoma skin cancer (NMSC) has been observed. NMSC in RTRs are often more numerous and biologically more aggressive than the general population, thus contributing towards an increase in morbidity and to a lesser degree, mortality. The resultant cumulative health and financial burden is a recognized concern. Proposed strategies in mitigating risks of developing NMSC and early therapeutic options thereof include tailored modification of immunosuppressants in conjunction with sun protection in all transplant patients. This review highlights the clinical and financial burden of transplant-associated skin cancers, carcinogenic mechanisms in association with immunosuppression, importance of skin cancer awareness campaign and integrated transplant skin clinic, and the potential role of chemoprotective agents. A scheme is proposed for primary and secondary prevention of NMSC based on the available evidence.

Calcineurin Inhibitors Nephrotoxicity Prevention Strategies With Stress on Belatacept-Based Rescue Immunotherapy: A Review of the Current Evidence

BACKGROUND

A traditional narrative review was performed to evaluate clinical studies that have examined the clinical implications, risk factors, and prevention of calcineurin inhibitors (CNIs) nephrotoxicity with stress on a belatacept-based rescue regimen.

METHODS

The Cochrane Library, PubMed/MEDLINE, EBSCO (Academic Search Ultimate), ProQuest (Central), and Excerpta Medical databases and Google scholar were searched using the keywords (CNI AND Nephrotoxicity prevention) OR ("Calcineurin inhibitor" AND Nephrotoxicity) OR (Tacrolimus AND Nephrotoxicity) OR (Ciclosporin AND Nephrotoxicity) OR (cyclosporine AND Nephrotoxicity) OR (Belatacept) OR (CNI Conversion) for the period from 1990 to 2020. Fifty-five related articles and reviews were found.

CONCLUSION

A better understanding of the mechanisms underlying calcineurin inhibitor nephrotoxicity could help in the individualization of therapy for and prevention of CNI nephrotoxicity. Identification of high-risk patients for CNI nephrotoxicity before renal transplantation enables better use and selection of immunosuppression with reduced adverse effects and, eventually, successful treatment of the kidney recipients. Belatacept conversion is a good and safe option in patients with deteriorating renal function attributed to CNI nephrotoxicity.

Current State of Evidence on Kidney Transplantation: How Fragile Are the Results?

BACKGROUND

The study aims is to use the fragility index (FI) to examine the strength of evidence of randomized controlled trials (RCTs) published in the last decade on kidney transplantation.

METHODS

We searched MEDLINE for studies on kidney transplantation. We included the RCTs that compared 2 groups with 1:1 randomization and reported significant P-values (<0.05) for a dichotomous outcome and were published in the top 10 transplant journals. We calculated the FI; a calculation used to determine the minimum number of subjects needed to change from a nonevent to an event to make the study results nonsignificant (P-value >0.05).

RESULTS

57 RCTs met our inclusion criteria. The median sample size was 100 participants in each arm, the median number of events was 16(IQR 8-30) in the intervention group. Among the included trials, 79% were industry-funded, 93% involved medications, and the majority were open-label. The median FI was 3 (IQR 1-11). In 43% of the trials, the number of patients reported lost to follow-up was higher than or equal to the FI. Only 4% of the RCTs imputed a value for the missing dichotomous outcome. Furthermore, the median number of subjects who discontinued the trial due to adverse effects was 21, which was greater than the FI in 60% of the RCTs.

CONCLUSION

The arbitrary classification of results into "significant" and "nonsignificant" based on p-value <0.05 should perhaps be interpreted with the help of other statistical parameters and FI is one of them.

An open-label randomized clinical trial to evaluate the efficacy of everolimus versus tacrolimus in triple maintenance immunosuppressive therapy for kidney transplant patients

Tacrolimus (TAC), a calcineurin inhibitor, and everolimus (EVL), an mTOR inhibitor, have been used as immunosuppressive (ISS) drugs in post-kidney transplantation therapy. The objective of this study was to compare the efficacy of EVL vs TAC in the ISS maintenance triple therapy. Ninety-seven kidney transplant patients, who received triple maintenance therapy with TAC, mycophenolate mofetil (MMF), and methyl prednisone (PRED), were evaluated. After four months of post-kidney transplant therapy, 30 patients enrolled in a randomized controlled clinical trial, in which 16 patients received TAC+MMF+PRED (cohort 1), and 14 patients switched to EVL+MMF+PRED (cohort 2). The patients were followed-up for 36 months. Two patients from cohort 1 lost their grafts after one year due to non-adherence. Two patients from cohort 2 had intolerance to mTOR inhibitors and were switched back to TAC from EVL. One case (6.25%) in cohort 1 and three cases (21.43%) in cohort 2 of acute T-cell-mediated rejection was observed. Antibody-mediated acute rejection (ABMAR) was observed in four patients (25.0%) in cohort 1, and antibody-mediated chronic rejection (ABMCR) was observed in two patients (12.50%). One patient from cohort 2 lost the graft after 15 months due to polyomavirus infection. The graft survival rate was 87.50% in cohort 1 and 92.86% in cohort 2. This clinical trial showed that the EVL+MMF+PRED triple maintenance therapy was efficacious compared with TAC during 32 months of follow-up. However, further studies are needed to confirm the efficacy of this regimen for long-term graft survival.

Thirty Years of Tacrolimus in Clinical Practice

Tacrolimus was discovered in 1984 and entered clinical use shortly thereafter, contributing to successful solid organ transplantation across the globe. In this review, we cover development of tacrolimus, its evolving clinical utility, and issues affecting its current usage. Since earliest use of this class of immunosuppressant, concerns for calcineurin-inhibitor toxicity have led to efforts to minimize or eliminate these agents in clinical regimens but with limited success. Current understanding of the role of tacrolimus focuses more on its efficacy in preventing graft rejection and graft loss. As we enter the fourth decade of tacrolimus use, newer studies utilizing novel combinations (as with the mammalian target of rapamycin inhibitor, everolimus, and T-cell costimulation blockade with belatacept) offer potential for enhanced benefits.

Effect of Everolimus with Low-Dose Tacrolimus on Development of New-Onset Diabetes After Transplantation and Allograft Function in Kidney Transplantation: A Multicenter, Open-Label, Randomized Trial

Background

This randomized controlled trial aimed to investigate the effect of everolimus (EVL) with low-dose tacrolimus (Tac) on the development of post-transplantation diabetes mellitus (PTDM) in kidney transplantation (KT).

Material/Methods

Seventy-seven kidney transplant patients from 4 transplant centers were included. Patients were randomized to the “EVL group” (n=38) and the “TAC group” (n=39). The target Tac trough level was 2 to 5 ng/mL in the EVL group and 5 to 10 ng/mL in the TAC group.

Results

The 1-year cumulative incidence of PTDM in all patients was 7.8%, and no difference was found between the 2 groups (P=0.0819). Insulin resistance measured with the homeostatic model assessment for insulin resistance showed a significant increase only in the TAC group (1.11 to 1.30, P=0.0492). Allograft rejection rate and estimated glomerular filtration rate (eGFR) follow-ups every 3 months were not significantly different between the 2 groups. However, the EVL group showed a significant increase in the mean eGFR at 9 months and 12 months after KT compared to the baseline value (P=0.0242 and 0.0491, respectively).

The EVL group showed lower insulin resistance and higher allograft function in comparison to the TAC group.

Conclusions

EVL-based immunosuppressive therapy with lower Tac exposure could be a safer alternative for maintenance treatment.

Comparison of two strategies based on mammalian target of rapamycin inhibitors in secondary prevention of non-melanoma skin cancer after kidney transplantation, a pilot study

After kidney transplantation, withdrawal of calcineurin inhibitors (CNI) and conversion to sirolimus (SRL) may reduce the occurrence of new non-melanoma skin cancer (NMSC). Conversely, a reduced CNI exposure with everolimus (EVR) is an alternative strategy that has not been thoroughly evaluated. We retrospectively compared the occurrence of newly diagnosed NMSCs in two cohorts of kidney transplant recipients (KTR) with at least one NMSC: 35 patients were converted to EVR with reduced CNI exposure (CNI/EVR group), whereas 46 patients were converted to SRL in association with mycophenolic acid (MPA) (SRL/MPA group). Two years after conversion, survival free of new NMSC was similar between the two cohorts (p = .37), with 19 KTR (54.3%) in the CNI/EVR group and 22 (47.8%) in the SRL/MPA group being diagnosed of at least one new NMSC. Half of the KTR from both groups showed adverse events, leading to mTORi discontinuation for 37.1% of KTR in the CNI/EVR group and 21.7% in the SRL/MPA group (p = .09). The incidence of rejections was similar between the two groups. In a retrospective cohort of KTR with at least one post-transplant NMSC, the outcome of the patients converted to a CNI/EVR regimen was not different from those converted to a SRL/MPA regimen.

5-Year outcomes of the prospective and randomized CISTCERT study comparing steroid withdrawal to replacement of cyclosporine with everolimus in de novo kidney transplant patients

Withdrawal of either steroids or calcineurin inhibitors are two strategies to reduce treatment-related side effects and improve long-term outcomes of kidney transplantation. The CISTCERT study compared the efficacy and safety of these two strategies. In this multicenter, randomized controlled trial, 151 incident kidney transplant recipients received cyclosporine (CsA), mycophenolic acid (MPA), and steroids during three months, followed by either steroid withdrawal (CsA/MPA) or replacement of cyclosporine with everolimus (EVL) (EVL/MPA/steroids). 5-year patient survival (89% vs. 86%; P = NS) and death-censored graft survival (95% vs. 96%; P = NS) were comparable in the CsA/MPA and EVL/MPA/steroids arm, respectively. ⁵¹ CrEDTA clearance was comparable in the intention-to-treat analysis, but in the on-treatment population, the EVL/MPA/steroids arm exhibited a superior ⁵¹ CrEDTA clearance at 1 and 5 years after transplantation (61.6 vs. 52.4, P = 0.05 and 59.1 vs. 46.2ml/min/1.73 m² , P = 0.042). Numerically more and more severe rejections were observed in the EVL/MPA/steroids arm, which also experienced a higher incidence of posttransplant diabetes (26% vs. 6%, P = 0.0016) and infections. No significant differences were observed in cardiovascular outcomes and malignancy. Both regimens provide an excellent long-term patient survival and graft survival. Regarding graft function, EVL/MPA/steroids is an attractive strategy for patients with good tolerability who remain free of rejection. (ClinicalTrials.gov number: NCT00903188; EudraCT Number 2007-005844-26).

Early conversion to a CNI-free immunosuppression with SRL after renal transplantation-Long-term follow-up of a multicenter trial

Introduction

Early conversion to a CNI-free immunosuppression with SRL was associated with an improved 1- and 3- yr renal function as compared with a CsA-based regimen in the SMART-Trial. Mixed results were reported on the occurrence of donor specific antibodies under mTOR-Is. Here, we present long-term results of the SMART-Trial.

Methods and materials

N = 71 from 6 centers (n = 38 SRL and n = 33 CsA) of the original SMART-Trial (ITT n = 140) were enrolled in this observational, non-interventional extension study to collect retrospectively and prospectively follow-up data for the interval since baseline. Primary objective was the development of dnDSA. Blood samples were collected on average 8.7 years after transplantation.

Results

Development of dnDSA was not different (SRL 5/38, 13.2% vs. CsA 9/33, 27.3%; P = 0.097). GFR remained improved under SRL with 64.37 ml/min/1.73m² vs. 53.19 ml/min/1.73m² (p = 0.044). Patient survival did not differ between groups at 10 years. There was a trend towards a reduced graft failure rate (11.6% SRL vs. 23.9% CsA, p = 0.064) and less tumors under SRL (2.6% SRL vs. 15.2% CsA, p = 0.09).

Conclusions

An early conversion to SRL did not result in an increased incidence of dnDSA nor increased long-term risk for the recipient. Transplant function remains improved with benefits for the graft survival.

Conversion From Calcineurin Inhibitors to Belatacept in HLA-sensitized Kidney Transplant Recipients With Low-level Donor-specific Antibodies

BACKGROUND

Belatacept could be the treatment of choice in renal-transplant recipients with renal dysfunction attributed to calcineurin inhibitor (CNI) nephrotoxicity. Few studies have described its use in patients with donor-specific antibody (DSA).

METHODS

We retrospectively evaluated conversion from CNIs to belatacept in 29 human leukocyte antigen-immunized renal-transplant recipients. Data about acute rejection, DSA, and renal function were collected. These patients were compared with 42 nonimmunized patients treated with belatacept.

RESULTS

Patients were converted from CNIs to belatacept a median of 444 days (interquartile range, 85-1200) after transplantation and were followed up after belatacept conversion, for a median of 308 days (interquartile range, 125-511). At conversion, 16 patients had DSA. Nineteen DSA were observed in these 16 patients, of which 11/19 were <1000 mean fluorescence intensity (MFI), 7/19 were between 1000 and 3000 MFI, and one was >3000 MFI. At last follow-up, preexisting DSA had decreased or stabilized. Seven patients still had DSA with a mean MFI of 1298 ± 930 at the last follow-up. No patient developed a de novo DSA in the DSA-positive group. In the nonimmunized group, one patient developed de novo DSA (A24-MFI 970; biopsy for cause did not show biopsy-proven acute rejection or microinflammation score). After belatacept conversion, one antibody-mediated rejection was diagnosed. The mean estimated glomerular filtration rate improved from 31.7 ± 14.2 mL/min/1.73 m to 40.7 ± 12.3 mL/min/1.73 m (P < 0.0001) at 12 months after conversion. We did not find any significant difference between groups in terms of renal function, proteinuria, or biopsy-proven acute rejection.

CONCLUSIONS

We report on a safe conversion to belatacept in human leukocyte antigen-immunized patients with low DSA levels.

Tacrolimus- versus sirolimus-based immunosuppression after simultaneous pancreas and kidney transplantation: 5-year results of a randomized trial

Tacrolimus, the cornerstone immunosuppression after simultaneous pancreas and -kidney (SPK) transplantation, may exert nephrotoxic and diabetogenic effects. We therefore prospectively compared in an open-label, randomized, monocentric, 5-year follow-up study, a tacrolimus- and a sirolimus-based immunosuppressive regimen. Randomization using the block method allowing a blind allocation was done at the time of surgery. All patients received anti-thymocyte globulin and maintenance therapy with tacrolimus, mycophenolate mofetil, and steroids. At month 3, tacrolimus was continued or replaced by sirolimus. The primary endpoint was kidney and pancreas graft survival at 1 and 5 years. Fifty patients were included in the final analysis in each group. At 1 year, differences for kidney and pancreas graft survival between sirolimus and tacrolimus were 0% (90% confidence interval -4.61% to 4.61%) and 6% (90% confidence interval -6.32% to 18.32%), respectively. There was no difference in renal and pancreas graft survival at 5 years. Thirty-four patients (68%) in the sirolimus group vs three (6%) in the tacrolimus group needed definitive withdrawal of the study drug. Despite noninferiority of sirolimus compared to tacrolimus for kidney and pancreas graft survival, the high rate of sirolimus discontinuation does not favor its use as cornerstone therapy after SPK transplantation (NCT00693446).

Interventions to Prevent Nonmelanoma Skin Cancers in Recipients of a Solid Organ Transplant: Systematic Review of Randomized Controlled Trials

BACKGROUND

Organ transplant recipients are at high risk of developing skin cancer. The benefits and harms of interventions to prevent nonmelanoma skin cancer in solid organ transplant recipients have not been summarized.

METHODS

We searched MEDLINE, Embase, and CENTRAL through April 2018. Risk of bias was assessed using the Cochrane tool, and evidence certainty was evaluated using the Grades of Recommendation, Assessment, Development, and Evaluation process. Prespecified outcomes were nonmelanoma skin cancer, clearance and prevention of keratotic skin lesions, and intervention-specific adverse events.

RESULTS

Ninety-two trials (20 012 participants) were included. The evaluated treatments were cancer-specific interventions (acitretin, imiquimod, photodynamic therapy, nicotinamide, topical diclofenac, and selenium) and immunosuppression regimes (azathioprine, mycophenolate mofetil, calcineurin inhibitors, mammalian target of rapamycin [mTOR] inhibitors, belatacept, induction agents, and withdrawal of calcineurin inhibitors or corticosteroids). Effects on nonmelanoma skin cancer were uncertain for photodynamic therapy (3 trials, 93 participants, risk ratio [RR] 1.42 [95% confidence interval (CI), 0.65-3.11]; low certainty evidence), nicotinamide (2 trials, 60 participants), acitretin (2 trials, 61 participants), and imiquimod (1 trial, 20 participants) compared to control. mTOR inhibitors probably reduced skin cancer compared to calcineurin inhibitors (12 trials, 2225 participants, RR 0.62 [95% CI, 0.45-0.85]; moderate certainty evidence). Photodynamic therapy may cause pain at the treatment site (4 trials, 95 patients, RR 17.09 [95% CI, 4.22-69.26]; low certainty evidence).

CONCLUSIONS

There is limited evidence for the efficacy and safety of specific treatments to prevent nonmelanoma skin cancers among solid organ transplant recipients.

Metabolic Disorders with Kidney Transplant

Metabolic disorders are highly prevalent in kidney transplant candidates and recipients and can adversely affect post-transplant graft outcomes. Management of diabetes, hyperparathyroidism, and obesity presents distinct opportunities to optimize patients both before and after transplant as well as the ability to track objective data over time to assess a patient's ability to partner effectively with the health care team and adhere to complex treatment regimens. Optimization of these particular disorders can most dramatically decrease the risk of surgical and cardiovascular complications post-transplant. Approximately 60% of nondiabetic patients experience hyperglycemia in the immediate post-transplant phase. Multiple risk factors have been identified related to development of new onset diabetes after transplant, and it is estimated that upward of 7%-30% of patients will develop new onset diabetes within the first year post-transplant. There are a number of medications studied in the kidney transplant population for diabetes management, and recent data and the risks and benefits of each regimen should be optimized. Secondary hyperparathyroidism occurs in most patients with CKD and can persist after kidney transplant in up to 66% of patients, despite an initial decrease in parathyroid hormone levels. Parathyroidectomy and medical management are the options for treatment of secondary hyperparathyroidism, but there is no randomized, controlled trial providing clear recommendations for optimal management, and patient-specific factors should be considered. Obesity is the most common metabolic disorder affecting the transplant population in both the pre- and post-transplant phases of care. Not only does obesity have associations and interactions with comorbid illnesses, such as diabetes, dyslipidemia, and cardiovascular disease, all of which increase morbidity and mortality post-transplant, but it also is intimately inter-related with access to transplantation for patients with kidney failure. We review these metabolic disorders and their management, including data in patients with kidney transplants.

Combination of calcineurin and mTOR inhibitors in kidney transplantation: a propensity score analysis based on current clinical practice

INTRODUCTION

The TRANSFORM study demonstrated that an immunosuppression based on a combination of calcineurin inhibitors and de-novo mTOR inhibitors (mTORi) is safe and effective in kidney transplant recipients. However, data that validate this approach in clinical practice are currently missing.

MATERIALS AND METHODS

Analysis of 401 kidney transplant recipients transplanted from June 2013 to December 2016. All patients received tacrolimus with prednisone in combination with either mycophenolate (n = 186) or mTORi (either everolimus or sirolimus, n = 215). A propensity score to receive mTORi was calculated based on the inverse probability of treatment weighting (IPTW) from the following parameters: age and sex of donor and recipient, BMI, previous transplants, diabetes, cPRA, dialysis before transplantation, dialysis vintage, type of donor, ABO-incompatibility, HLA-mismatches, induction and ischemia time. Median follow-up was 2.6 [1.9; 3.7] years.

RESULTS

Cox-regression analysis suggests good results for mTORi versus MPA in terms of 1-year biopsy-proven acute rejection (BPAR, P = 0.063), 1-year graft loss (P = 0.025) and patient survival (P < 0.001). Results observed for BPAR and graft failure were largely attributed to those patients that would have been excluded by the TRANSFORM because of some exclusion criteria (52.9% of the population, P = 0.003 for 1-year BPAR and P = 0.040 for graft loss). In patients who met selection criteria for TRANSFORM, no effect of treatment for BPAR or graft failure was observed, while the beneficial effect on overall survival persisted.

CONCLUSIONS

In a real-life setting, a protocol based on de-novo mTORi with tacrolimus and prednisone could be employed as a standard immunosuppressive regimen and was associated with good outcomes.

Target of rapamycin inhibitors (TOR-I; sirolimus and everolimus) for primary immunosuppression in kidney transplant recipients

BACKGROUND

Kidney transplantation is the therapy of choice for many patients with end-stage kidney disease (ESKD) with an improvement in survival rates and satisfactory short term graft survival. However, there has been little improvement in long-term survival. The place of target of rapamycin inhibitors (TOR-I) (sirolimus, everolimus), which have different modes of action from other commonly used immunosuppressive agents, in kidney transplantation remains uncertain. This is an update of a review first published in 2006.

OBJECTIVES

To evaluate the short and long-term benefits and harms of TOR-I (sirolimus and everolimus) when used in primary immunosuppressive regimens for kidney transplant recipients.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 20 September 2019 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register were identified through searches of CENTRAL, MEDLINE and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

All randomised controlled trials (RCTs) and quasi-RCTs in which drug regimens, containing TOR-I commenced within seven days of transplant, were compared to alternative drug regimens, were included without age restriction, dosage or language of report.

DATA COLLECTION AND ANALYSIS

Three authors independently assessed study eligibility, risk of bias, and extracted data. Results were reported as risk ratios (RR) with 95% confidence intervals (CI) for dichotomous outcomes and mean difference (MD) with 95% CI for continuous outcomes. Statistical analyses were performed using the random-effects model. The certainty of the evidence was assessed using GRADE MAIN RESULTS: Seventy studies (17,462 randomised participants) were included; eight studies included two comparisons to provide 78 comparisons. Outcomes were reported at six months to three years post transplant. Risk of bias was judged to be low for sequence generation in 25 studies, for allocation concealment in 23 studies, performance bias in four studies, detection bias in 65 studies, attrition bias in 45 studies, selective reporting bias in 48 studies, and for other potential bias in three studies. Risk of bias was judged to be at high risk of bias for sequence generation in two studies, allocation concealment in two studies, performance bias in 61 studies, detection bias in one study, attrition bias in four studies, for selective reporting bias in 11 studies and for other potential risk of bias in 46 studies. Compared with CNI and antimetabolite, TOR-I with antimetabolite probably makes little or no difference to death (RR 1.31, 95% CI 0.87 to 1.98; 19 studies) or malignancies (RR 0.86, 95% CI 0.50 to 1.48; 10 studies); probably increases graft loss censored for death (RR 1.32, 95% CI 0.96 to 1.81; 15 studies), biopsy-proven acute rejection (RR 1.60, 95% CI 1.25 to 2.04; 15 studies), need to change treatment (RR 2.42, 95% CI 1.88 to 3.11; 14 studies) and wound complications (RR 2.56, 95% CI 1.94 to 3.36; 12 studies) (moderate certainty evidence); but reduces CMV infection (RR 0.43, 95% CI 0.29 to 0.63; 13 studies) (high certainty evidence). Compared with antimetabolites and CNI, TOR-I with CNI probably makes little or no difference to death (RR 1.06, 95% CI 0.84 to 1.33; 31 studies), graft loss censored for death (RR 1.09, 95% CI 0.82 to 1.45; 26 studies), biopsy-proven acute rejection (RR 0.95, 95% CI 0.81 to 1.12; 24 studies); and malignancies (RR 0.83, 95% CI 0.64 to 1.07; 17 studies); probably increases the need to change treatment (RR 1.56, 95% CI 1.28 to 1.90; 25 studies), and wound complications (RR 1.56, 95% CI 1.28 to 1.91; 17 studies); but probably reduces CMV infection (RR 0.44, 95% CI 0.34 to 0.58; 25 studies) (moderate certainty evidence). Lower dose TOR-I and standard dose CNI compared with higher dose TOR-I and reduced dose CNI probably makes little or no difference to death (RR 1.07, 95% CI 0.64 to 1.78; 9 studies), graft loss censored for death (RR 1.09, 95% CI 0.54 to 2.20; 8 studies), biopsy-proven acute rejection (RR 0.87, 95% CI 0.67 to 1.13; 8 studies), and CMV infection (RR 1.42, 95% CI 0.78 to 2.60; 5 studies) (moderate certainty evidence); and may make little or no difference to wound complications (RR 0.95, 95% CI 0.53 to 1.71; 3 studies), malignancies (RR 1.04, 95% CI 0.36 to 3.04; 7 studies), and the need to change treatments (RR 1.18, 95% CI 0.58 to 2.42; 5 studies) (low certainty evidence). Lower dose of TOR-I compared with higher doses probably makes little or no difference to death (RR 0.84, 95% CI 0.67 to 1.06; 13 studies), graft loss censored for death (RR 0.92, 95% CI 0.71 to 1.19; 12 studies), biopsy-proven acute rejection (RR 1.26, 95% CI 1.10 to 1.43; 11 studies), CMV infection (RR 0.87, 95% CI 0.63 to 1.21; 9 studies), wound complications (RR 0.92, 95% CI 0.66 to 1.29; 7 studies), and malignancy (RR 0.84, 95% CI 0.54 to 1.32; 10 studies) (moderate certainty evidence); and may make little or no difference to the need to change treatments (RR 0.91, 95% CI 0.78 to 1.05; 10 studies) (low certainty evidence). It is uncertain whether sirolimus and everolimus differ in their effects on kidney function and lipid levels because the certainty of the evidence is very low based on a single small study with only three months of follow-up.

AUTHORS' CONCLUSIONS

In studies with follow-up to three years, TOR-I with an antimetabolite increases the risk of graft loss and acute rejection compared with CNI and an antimetabolite. TOR-I with CNI potentially offers an alternative to an antimetabolite with CNI as rates of graft loss and acute rejection are similar between interventions and TOR-I regimens are associated with a reduced risk of CMV infections. Wound complications and the need to change immunosuppressive medications are higher with TOR-I regimens. While further new studies are not required, longer-term follow-up data from participants in existing methodologically robust RCTs are needed to determine how useful immunosuppressive regimens, which include TOR-I, are in maintaining kidney transplant function and survival beyond three years.

Inhibition of the mTOR pathway: A new mechanism of β cell toxicity induced by tacrolimus

The mechanisms of tacrolimus-induced β cell toxicity are unknown. Tacrolimus (TAC) and rapamycin (Rapa) both bind to FK506-binding protein 12 (FKBP12). Also, both molecular structures are similar. Because of this similarity, we hypothesized that TAC can also inhibit the mTOR signalling, constituting a possible mechanism of β cell toxicity. Thus, we studied the effect of TAC and Rapa over the mTOR pathway, v-maf musculoaponeurotic fibrosarcoma oncogene homolog A (MafA), and insulin secretion and content in INS-1 β cells treated with or without glucose and palmitate and in islets from lean or obese rats. TAC and Rapa inhibited the mTOR pathway as reflected by lower levels of phospho-mTOR, phospo-p70S6K, and phospo-S6. The effect of Rapa was larger than TAC. Both drugs reduced the levels of MafA, insulin secretion, and content although these effects were larger with TAC. The changes on MafA and insulin metabolism were observed in cells on glucose and palmitate, in obese animals, and were absent in cells on maintenance medium or in lean animals. In silico docking and immunoprecipitation experiments confirmed that TAC can form a stable noncovalent interaction with FKBP12-mTOR. Thus, the mTOR inhibition may be a mechanism contributing to the diabetogenic effect of TAC.

Acute Rejection in Kidney Transplantation and Early Beginning of Tacrolimus

BACKGROUND

Although tacrolimus is an effective immunosuppressive drug used for preventing biopsy proven acute rejection (BPAR) in kidney transplanted patients, its nephrotoxicity may compromise renal function and lead to delayed initiation because of its side effects. This study aimed to evaluate the safety of early initiation of tacrolimus in the occurrence of BPAR during the first 90 days post transplant.

METHODS

We conducted a retrospective cohort study involving 315 patients who underwent kidney transplantation from 2015 to 2017. Comparisons were performed between 2 groups according to whether the start time of tacrolimus therapy was delayed or not delayed. Cox proportional hazards models were used to examine the association between variables and the occurrence of BPAR.

RESULTS

The incidence of BPAR was 14.9% (n = 47) and it was significantly higher in the delayed group (19.4% vs 6.4%; P = .002). Delayed initiation tacrolimus group was significantly associated with the risk of BPAR (hazard ratio: 2.95; P < .036). The overall mortality rate was 2.5% (n = 8) and there was no association between delayed initiation therapy and death (P = .56).

CONCLUSION

Our study confirmed that delayed initiation of tacrolimus in patients with delayed graft function is associated with a high risk of BPAR.

Therapeutic Use of mTOR Inhibitors in Renal Diseases: Advances, Drawbacks, and Challenges

The mammalian (or mechanistic) target of rapamycin (mTOR) pathway has a key role in the regulation of a variety of biological processes pivotal for cellular life, aging, and death. Impaired activity of mTOR complexes (mTORC1/mTORC2), particularly mTORC1 overactivation, has been implicated in a plethora of age-related disorders, including human renal diseases. Since the discovery of rapamycin (or sirolimus), more than four decades ago, advances in our understanding of how mTOR participates in renal physiological and pathological mechanisms have grown exponentially, due to both preclinical studies in animal models with genetic modification of some mTOR components as well as due to evidence coming from the clinical experience. The main clinical indication of rapamycin is as immunosuppressive therapy for the prevention of allograft rejection, namely, in renal transplantation. However, considering the central participation of mTOR in the pathogenesis of other renal disorders, the use of rapamycin and its analogs meanwhile developed (rapalogues) everolimus and temsirolimus has been viewed as a promising pharmacological strategy. This article critically reviews the use of mTOR inhibitors in renal diseases. Firstly, we briefly overview the mTOR components and signaling as well as the pharmacological armamentarium targeting the mTOR pathway currently available or in the research and development stages. Thereafter, we revisit the mTOR pathway in renal physiology to conclude with the advances, drawbacks, and challenges regarding the use of mTOR inhibitors, in a translational perspective, in four classes of renal diseases: kidney transplantation, polycystic kidney diseases, renal carcinomas, and diabetic nephropathy.

Onset and progression of diabetes in kidney transplant patients receiving everolimus or cyclosporine therapy: an analysis of two randomized, multicenter trials

Background

Conversion from calcineurin inhibitor (CNI) therapy to a mammalian target of rapamycin (mTOR) inhibitor following kidney transplantation may help to preserve graft function. Data are sparse, however, concerning the impact of conversion on posttransplant diabetes mellitus (PTDM) or the progression of pre-existing diabetes.

Methods

PTDM and other diabetes-related parameters were assessed post hoc in two large open-label multicenter trials. Kidney transplant recipients were randomized (i) at month 4.5 to switch to everolimus or remain on a standard cyclosporine (CsA)-based regimen (ZEUS, n = 300), or (ii) at month 3 to switch to everolimus, remain on standard CNI therapy or convert to everolimus with reduced-exposure CsA (HERAKLES, n = 497).

Results

There were no significant differences in the incidence of PTDM between treatment groups (log rank p = 0.97 [ZEUS], p = 0.90 [HERAKLES]). The mean change in random blood glucose from randomization to month 12 was also similar between treatment groups in both trials for patients with or without PTDM, and with or without pre-existing diabetes. The change in eGFR from randomization to month 12 showed a benefit for everolimus versus comparator groups in all subpopulations, but only reached significance in larger subgroups (no PTDM or no pre-existing diabetes).

Conclusions

Within the restrictions of this post hoc analysis, including non-standardized diagnostic criteria and limited glycemia laboratory parameters, these data do not indicate any difference in the incidence or severity of PTDM with early conversion from a CsA-based regimen to everolimus, or in the progression of pre-existing diabetes.

Trial registration

clinicaltrials.gov, NCT00154310 (registered September 2005) and NCT00514514 (registered August 2007); EudraCT (2006-007021-32 and 2004-004346-40).

Electronic supplementary material

The online version of this article (10.1186/s12882-018-1031-1) contains supplementary material, which is available to authorized users.

Efficacy and Safety of a Tofacitinib-based Immunosuppressive Regimen After Kidney Transplantation: Results From a Long-term Extension Trial

Background

Tofacitinib is an oral Janus kinase inhibitor. This open-label, long-term extension (LTE) study (NCT00658359) evaluated long-term tofacitinib treatment in stable kidney transplant recipients (n = 178) posttransplant.

Methods

Patients who completed 12 months of cyclosporine (CsA) or tofacitinib treatment in the phase IIb parent study (NCT00483756) were enrolled into this LTE study, evaluating long-term tofacitinib treatment over months 12 to 72 posttransplant. Patients were analyzed by tofacitinib less-intensive (LI) or more-intensive (MI) regimens received in the parent study. For both groups, tofacitinib dose was reduced from 10 to 5 mg twice daily by 6 months into the LTE. Patients were followed up through month 72 posttransplant, with a focus on month 36 results.

Results

Tofacitinib demonstrated similar 36-month patient and graft survival rates to CsA. Biopsy-proven acute rejection rates at month 36 were 11.2% for CsA, versus 10.0% and 7.4% (both P > 0.05) for tofacitinib LI and MI, respectively. Least squares mean estimated glomerular filtration rates were 9 to 15 mL/min per 1.73 m² higher for tofacitinib versus CsA at month 36. The proportions of patients with grade 2/3 interstitial fibrosis and tubular atrophy in month 36 protocol biopsies were 20.0% for LI and 18.2% for MI (both P > 0.05) versus 33.3% for CsA. Kaplan-Meier cumulative serious infection rates at month 36 were numerically higher for tofacitinib LI (43.9%; P = 0.45) and significantly higher for MI (55.9%; P < 0.05) versus CsA (37.1%).

Conclusions

Long-term tofacitinib continued to be effective in preventing renal allograft acute rejection and preserving renal function. However, long-term tofacitinib and mycophenolic acid product combination was associated with persistent serious infection risk.

Risk factors associated with post-kidney transplant malignancies: an article from the Cancer-Kidney International Network

In kidney transplant recipients, cancer is one of the leading causes of death with a functioning graft beyond the first year of kidney transplantation, and malignancies account for 8-10% of all deaths in the USA (2.6 deaths/1000 patient-years) and exceed 30% of deaths in Australia (5/1000 patient-years) in kidney transplant recipients. Patient-, transplant- and medication-related factors contribute to the increased cancer risk following kidney transplantation. While it is well established that the overall immunosuppressive dose is associated with an increased risk for cancer following transplantation, the contributive effect of different immunosuppressive agents is not well established. In this review we will discuss the different risk factors for malignancies after kidney transplantation.

Effects of mTOR-Is on malignancy and survival following renal transplantation: A systematic review and meta-analysis of randomized trials with a minimum follow-up of 24 months

Background

mTOR-Is positively influence the occurrence and course of certain tumors after solid organ transplantation. The effect of mTOR-Is on the overall incidence of tumors irrespective of their origin is not entirely clear. Furthermore, conflicting data have been shown on mortality under mTOR-Is.

Methods

The current literature was searched for prospective randomized controlled renal transplantation trials. There were 1415 trials screened of which 13 could be included (pts. = 5924). A minimum follow-up of 24 months was mandatory for inclusion. Incidence of malignancies and patient survival was assessed in meta-analyses.

Results

The average follow-up of all trials was 40.6 months. Malignancy was significantly reduced under mTOR-Is compared to CNIs (RR 0.70, CI 0.49–0.99, p = 0.046). This effect remained stable when combined with CNIs (RR 0.58, CI 0.34–1.00, p = 0.05). When NMSCs were excluded the risk for malignancy remained significantly reduced under mTOR-I therapy (mono and combi) (RR 0.43, CI 0.24–0.77, p = 0.0046). Graft survival was minimally decreased under mTOR-Is (RR 0.99, CI 0.98–1.00, p = 0.054). This effect was abrogated when mTOR-Is were combined with CNIs (RR 0.99, CI 0.97–1.02, p = 0.50). Patient survival was not different (RR 1.00, CI 0.99–1.01, p = 0.54).

Conclusions

Posttransplant patients have a lower incidence of malignancy when treated with an mTOR-I no matter if it is used in combination with CNIs or not. This beneficial effect remains significant even when NMSCs are excluded. With currently used mTOR-I-based regimen patient and graft survival is not different compared to CNI therapies.

ESCMID Study Group for Infections in Compromised Hosts (ESGICH) Consensus Document on the safety of targeted and biological therapies: an infectious diseases perspective (Intracellular signaling pathways: tyrosine kinase and mTOR inhibitors)

BACKGROUND

The present review is part of the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Study Group for Infections in Compromised Hosts (ESGICH) Consensus Document on the safety of targeted and biologic therapies.

AIMS

To review, from an infectious diseases perspective, the safety profile of therapies targeting different intracellular signaling pathways and to suggest preventive recommendations.

SOURCES

Computer-based Medline searches with MeSH terms pertaining to each agent or therapeutic family.

CONTENT

Although BCR-ABL tyrosine kinase inhibitors modestly increase the overall risk of infection, dasatinib has been associated with cytomegalovirus and hepatitis B virus reactivation. BRAF/MEK kinase inhibitors do not significantly affect infection susceptibility. The effect of Bruton tyrosine kinase inhibitors (ibrutinib) among patients with B-cell malignancies is difficult to distinguish from that of previous immunosuppression. However, cases of Pneumocystis jirovecii pneumonia (PCP), invasive fungal infection and progressive multifocal leukoencephalopathy have been occasionally reported. Because phosphatidylinositol-3-kinase inhibitors (idelalisib) may predispose to opportunistic infections, anti-Pneumocystis prophylaxis and prevention strategies for cytomegalovirus are recommended. No increased rates of infection have been observed with venetoclax (antiapoptotic protein Bcl-2 inhibitor). Therapy with Janus kinase inhibitors markedly increases the incidence of infection. Pretreatment screening for chronic hepatitis B virus and latent tuberculosis infection must be performed, and anti-Pneumocystis prophylaxis should be considered for patients with additional risk factors. Cancer patients receiving mTOR inhibitors face an increased incidence of overall infection, especially those with additional risk factors (prior therapies or delayed wound healing).

IMPLICATIONS

Specific preventive approaches are warranted in view of the increased risk of infection associated with some of the reviewed agents.

Immunosuppressive therapy for kidney transplantation in adults: a systematic review and economic model

BACKGROUND

End-stage renal disease is a long-term irreversible decline in kidney function requiring renal replacement therapy: kidney transplantation, haemodialysis or peritoneal dialysis. The preferred option is kidney transplantation, followed by immunosuppressive therapy (induction and maintenance therapy) to reduce the risk of kidney rejection and prolong graft survival.

OBJECTIVES

To review and update the evidence for the clinical effectiveness and cost-effectiveness of basiliximab (BAS) (Simulect(®), Novartis Pharmaceuticals UK Ltd) and rabbit anti-human thymocyte immunoglobulin (rATG) (Thymoglobulin(®), Sanofi) as induction therapy, and immediate-release tacrolimus (TAC) (Adoport(®), Sandoz; Capexion(®), Mylan; Modigraf(®), Astellas Pharma; Perixis(®), Accord Healthcare; Prograf(®), Astellas Pharma; Tacni(®), Teva; Vivadex(®), Dexcel Pharma), prolonged-release tacrolimus (Advagraf(®) Astellas Pharma), belatacept (BEL) (Nulojix(®), Bristol-Myers Squibb), mycophenolate mofetil (MMF) (Arzip(®), Zentiva; CellCept(®), Roche Products; Myfenax(®), Teva), mycophenolate sodium (MPS) (Myfortic(®), Novartis Pharmaceuticals UK Ltd), sirolimus (SRL) (Rapamune(®), Pfizer) and everolimus (EVL) (Certican(®), Novartis) as maintenance therapy in adult renal transplantation.

METHODS

Clinical effectiveness searches were conducted until 18 November 2014 in MEDLINE (via Ovid), EMBASE (via Ovid), Cochrane Central Register of Controlled Trials (via Wiley Online Library) and Web of Science (via ISI), Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects and Health Technology Assessment (The Cochrane Library via Wiley Online Library) and Health Management Information Consortium (via Ovid). Cost-effectiveness searches were conducted until 18 November 2014 using a costs or economic literature search filter in MEDLINE (via Ovid), EMBASE (via Ovid), NHS Economic Evaluation Database (via Wiley Online Library), Web of Science (via ISI), Health Economic Evaluations Database (via Wiley Online Library) and the American Economic Association's electronic bibliography (via EconLit, EBSCOhost). Included studies were selected according to predefined methods and criteria. A random-effects model was used to analyse clinical effectiveness data (odds ratios for binary data and mean differences for continuous data). Network meta-analyses were undertaken within a Bayesian framework. A new discrete time-state transition economic model (semi-Markov) was developed, with acute rejection, graft function (GRF) and new-onset diabetes mellitus used to extrapolate graft survival. Recipients were assumed to be in one of three health states: functioning graft, graft loss or death.

RESULTS

Eighty-nine randomised controlled trials (RCTs), of variable quality, were included. For induction therapy, no treatment appeared more effective than another in reducing graft loss or mortality. Compared with placebo/no induction, rATG and BAS appeared more effective in reducing biopsy-proven acute rejection (BPAR) and BAS appeared more effective at improving GRF. For maintenance therapy, no treatment was better for all outcomes and no treatment appeared most effective at reducing graft loss. BEL + MMF appeared more effective than TAC + MMF and SRL + MMF at reducing mortality. MMF + CSA (ciclosporin), TAC + MMF, SRL + TAC, TAC + AZA (azathioprine) and EVL + CSA appeared more effective than CSA + AZA and EVL + MPS at reducing BPAR. SRL + AZA, TAC + AZA, TAC + MMF and BEL + MMF appeared to improve GRF compared with CSA + AZA and MMF + CSA. In the base-case deterministic and probabilistic analyses, BAS, MMF and TAC were predicted to be cost-effective at £20,000 and £30,000 per quality-adjusted life-year (QALY). When comparing all regimens, only BAS + TAC + MMF was cost-effective at £20,000 and £30,000 per QALY.

LIMITATIONS

For included trials, there was substantial methodological heterogeneity, few trials reported follow-up beyond 1 year, and there were insufficient data to perform subgroup analysis. Treatment discontinuation and switching were not modelled.

FUTURE WORK

High-quality, better-reported, longer-term RCTs are needed. Ideally, these would be sufficiently powered for subgroup analysis and include health-related quality of life as an outcome.

CONCLUSION

Only a regimen of BAS induction followed by maintenance with TAC and MMF is likely to be cost-effective at £20,000-30,000 per QALY.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42014013189.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Immunosuppressive therapy for kidney transplantation in children and adolescents: systematic review and economic evaluation

BACKGROUND

End-stage renal disease is a long-term irreversible decline in kidney function requiring kidney transplantation, haemodialysis or peritoneal dialysis. The preferred option is kidney transplantation followed by induction and maintenance immunosuppressive therapy to reduce the risk of kidney rejection and prolong graft survival.

OBJECTIVES

To systematically review and update the evidence for the clinical effectiveness and cost-effectiveness of basiliximab (BAS) (Simulect,(®) Novartis Pharmaceuticals) and rabbit antihuman thymocyte immunoglobulin (Thymoglobuline,(®) Sanofi) as induction therapy and immediate-release tacrolimus [Adoport(®) (Sandoz); Capexion(®) (Mylan); Modigraf(®) (Astellas Pharma); Perixis(®) (Accord Healthcare); Prograf(®) (Astellas Pharma); Tacni(®) (Teva); Vivadex(®) (Dexcel Pharma)], prolonged-release tacrolimus (Advagraf,(®) Astellas Pharma); belatacept (BEL) (Nulojix,(®) Bristol-Myers Squibb), mycophenolate mofetil (MMF) [Arzip(®) (Zentiva), CellCept(®) (Roche Products), Myfenax(®) (Teva), generic MMF is manufactured by Accord Healthcare, Actavis, Arrow Pharmaceuticals, Dr Reddy's Laboratories, Mylan, Sandoz and Wockhardt], mycophenolate sodium, sirolimus (Rapamune,(®) Pfizer) and everolimus (Certican,(®) Novartis Pharmaceuticals) as maintenance therapy in children and adolescents undergoing renal transplantation.

DATA SOURCES

Clinical effectiveness searches were conducted to 7 January 2015 in MEDLINE (via Ovid), EMBASE (via Ovid), Cochrane Central Register of Controlled Trials (via Wiley Online Library) and Web of Science [via Institute for Scientific Information (ISI)], Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects and Health Technology Assessment (HTA) (The Cochrane Library via Wiley Online Library) and Health Management Information Consortium (via Ovid). Cost-effectiveness searches were conducted to 15 January 2015 using a costs or economic literature search filter in MEDLINE (via Ovid), EMBASE (via Ovid), NHS Economic Evaluation Databases (via Wiley Online Library), Web of Science (via ISI), Health Economic Evaluations Database (via Wiley Online Library) and EconLit (via EBSCOhost).

REVIEW METHODS

Titles and abstracts were screened according to predefined inclusion criteria, as were full texts of identified studies. Included studies were extracted and quality appraised. Data were meta-analysed when appropriate. A new discrete time state transition economic model (semi-Markov) was developed; graft function, and incidences of acute rejection and new-onset diabetes mellitus were used to extrapolate graft survival. Recipients were assumed to be in one of three health states: functioning graft, graft loss or death.

RESULTS

Three randomised controlled trials (RCTs) and four non-RCTs were included. The RCTs only evaluated BAS and tacrolimus (TAC). No statistically significant differences in key outcomes were found between BAS and placebo/no induction. Statistically significantly higher graft function (p < 0.01) and less biopsy-proven acute rejection (odds ratio 0.29, 95% confidence interval 0.15 to 0.57) was found between TAC and ciclosporin (CSA). Only one cost-effectiveness study was identified, which informed NICE guidance TA99. BAS [with TAC and azathioprine (AZA)] was predicted to be cost-effective at £20,000-30,000 per quality-adjusted life year (QALY) versus no induction (BAS was dominant). BAS (with CSA and MMF) was not predicted to be cost-effective at £20,000-30,000 per QALY versus no induction (BAS was dominated). TAC (with AZA) was predicted to be cost-effective at £20,000-30,000 per QALY versus CSA (TAC was dominant). A model based on adult evidence suggests that at a cost-effectiveness threshold of £20,000-30,000 per QALY, BAS and TAC are cost-effective in all considered combinations; MMF was also cost-effective with CSA but not TAC.

LIMITATIONS

The RCT evidence is very limited; analyses comparing all interventions need to rely on adult evidence.

CONCLUSIONS

TAC is likely to be cost-effective (vs. CSA, in combination with AZA) at £20,000-30,000 per QALY. Analysis based on one RCT found BAS to be dominant, but analysis based on another RCT found BAS to be dominated. BAS plus TAC and AZA was predicted to be cost-effective at £20,000-30,000 per QALY when all regimens were compared using extrapolated adult evidence. High-quality primary effectiveness research is needed. The UK Renal Registry could form the basis for a prospective primary study.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42014013544.

FUNDING

The National Institute for Health Research HTA programme.

Management Strategies for Posttransplant Diabetes Mellitus after Heart Transplantation: A Review

Posttransplant diabetes mellitus (PTDM) is a well-recognized complication of heart transplantation and is associated with increased morbidity and mortality. Previous studies have yielded wide ranging estimates in the incidence of PTDM due in part to variable definitions applied. In addition, there is a limited published data on the management of PTDM after heart transplantation and a paucity of studies examining the effects of newer classes of hypoglycaemic drug therapies. In this review, we discuss the role of established glucose-lowering therapies and the rationale and emerging clinical evidence that supports the role of incretin-based therapies (glucagon like peptide- (GLP-) 1 agonists and dipeptidyl peptidase- (DPP-) 4 inhibitors) and sodium-glucose cotransporter 2 (SGLT2) inhibitors in the management of PTDM after heart transplantation. Recently published Consensus Guidelines for the diagnosis of PTDM will hopefully lead to more consistent approaches to the diagnosis of PTDM and provide a platform for the larger-scale multicentre trials that will be needed to determine the role of these newer therapies in the management of PTDM.

De Novo Malignancies After Liver Transplantation: A Single Institution Experience

OBJECTIVES

Our objective was to analyze characteristics, risk factors, and incidence of de novo malignancies after liver transplant.

MATERIALS AND METHODS

The hospital records of 557 patients who underwent liver transplant were analyzed from the point of de novo malignancy development. We evaluated the demographic features and survival of these patients retrospectively.

RESULTS

The research covered 429 patients, 9 (2%) of whom developed de novo malignancy. All of these patients were male (100%), and their mean (SD) age was 51.33 (4.69) years (range, 45-65 y). Indications for transplant included alcohol related in 4 cases, chronic hepatitis B in 2 cases, chronic hepatitis B and C in 1 case, chronic hepatitis B and D in 1 case, and chronic hepatitis C and alcohol-related cirrhosis in 1 case. The mean (SD) time from transplant to cancer diagnosis was 63.41 (37.10) months (range, 17-122 mo). The types of tumors were lung cancer, lymphoma, neuroendocrine tumor of lung, nasopharyngeal cancer, and squamous cell carcinoma of the skin. Seven cases received chemotherapy with or without radiotherapy. Two cases received surgery and radiotherapy. One patient underwent surgical treatment. One patient died before treatment was started.

CONCLUSIONS

In recent years, improvements in surgical techniques and immunosuppressive therapies have helped prolong survival of patients who undergo liver transplant. However, this also has led to a rise in the incidence of long-term complications such as de novo malignancy. These patients are more likely to develop de novo malignancy than the general population, for which chronic immunosuppression is identified as a major risk factor. Early diagnosis and treatment of de novo malignancies can help obtain better prognosis and higher survival rates in these patients.

Calcineurin inhibitor withdrawal or tapering for kidney transplant recipients

BACKGROUND

Calcineurin inhibitors (CNI) can reduce acute transplant rejection and immediate graft loss but are associated with significant adverse effects such as hypertension and nephrotoxicity which may contribute to chronic rejection. CNI toxicity has led to numerous studies investigating CNI withdrawal and tapering strategies. Despite this, uncertainty remains about minimisation or withdrawal of CNI.

OBJECTIVES

This review aimed to look at the benefits and harms of CNI tapering or withdrawal in terms of graft function and loss, incidence of acute rejection episodes, treatment-related side effects (hypertension, hyperlipidaemia) and death.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Specialised Register to 11 October 2016 through contact with the Information Specialist using search terms relevant to this review. Studies contained in the Specialised Register are identified through search strategies specifically designed for CENTRAL, MEDLINE, and EMBASE; handsearching conference proceedings; and searching the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

All randomised controlled trials (RCTs) where drug regimens containing CNI were compared to alternative drug regimens (CNI withdrawal, tapering or low dose) in the post-transplant period were included, without age or dosage restriction.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed studies for eligibility, risk of bias, and extracted data. Results were expressed as risk ratio (RR) or mean difference (MD) with 95% confidence intervals (CI).

MAIN RESULTS

We included 83 studies that involved 16,156 participants. Most were open-label studies; less than 30% of studies reported randomisation method and allocation concealment. Studies were analysed as intent-to-treat in 60% and all pre-specified outcomes were reported in 54 studies. The attrition and reporting bias were unclear in the remainder of the studies as factors used to judge bias were reported inconsistently. We also noted that 50% (47 studies) of studies were funded by the pharmaceutical industry.We classified studies into four groups: CNI withdrawal or avoidance with or without substitution with mammalian target of rapamycin inhibitors (mTOR-I); and low dose CNI with or without mTOR-I. The withdrawal groups were further stratified as avoidance and withdrawal subgroups for major outcomes.CNI withdrawal may lead to rejection (RR 2.54, 95% CI 1.56 to 4.12; moderate certainty evidence), may make little or no difference to death (RR 1.09, 95% CI 0.96 to 1.24; moderate certainty), and probably slightly reduces graft loss (RR 0.85, 95% CI 0.74 to 0.98; low quality evidence). Hypertension was probably reduced in the CNI withdrawal group (RR 0.82, 95% CI 0.71 to 0.95; low certainty), while CNI withdrawal may make little or no difference to malignancy (RR 1.10, 95% CI 0.93 to 1.30; low certainty), and probably makes little or no difference to cytomegalovirus (CMV) (RR 0.87, 95% CI 0.52 to 1.45; low certainty)CNI avoidance may result in increased acute rejection (RR 2.16, 95% CI 0.85 to 5.49; low certainty) but little or no difference in graft loss (RR 0.96, 95% CI 0.79 to 1.16; low certainty). Late CNI withdrawal increased acute rejection (RR 3.21, 95% CI 1.59 to 6.48; moderate certainty) but probably reduced graft loss (RR 0.84, 95% CI 0.72 to 0.97, low certainty).Results were similar when CNI avoidance or withdrawal was combined with the introduction of mTOR-I; acute rejection was probably increased (RR 1.43; 95% CI 1.15 to 1.78; moderate certainty) and there was probably little or no difference in death (RR 0.96; 95% CI 0.69 to 1.36, moderate certainty). mTOR-I substitution may make little or no difference to graft loss (RR 0.94, 95% CI 0.75 to 1.19; low certainty), probably makes little of no difference to hypertension (RR 0.86, 95% CI 0.64 to 1.15; moderate), and probably reduced the risk of cytomegalovirus (CMV) (RR 0.60, 95% CI 0.44 to 0.82; moderate certainty) and malignancy (RR 0.69, 95% CI 0.47 to 1.00; low certainty). Lymphoceles were increased with mTOR-I substitution (RR 1.45, 95% CI 0.95 to 2.21; low certainty).Low dose CNI combined with mTOR-I probably increased glomerular filtration rate (GFR) (MD 6.24 mL/min, 95% CI 3.28 to 9.119; moderate certainty), reduced graft loss (RR 0.75, 95% CI 0.55 to 1.02; moderate certainty), and made little or no difference to acute rejection (RR 1.13 ; 95% CI 0.91 to 1.40; moderate certainty). Hypertension was decreased (RR 0.98, 95% CI 0.80 to 1.20; low certainty) as was CMV (RR 0.41, 95% CI 0.16 to 1.06; low certainty). Low dose CNI plus mTOR-I makes probably makes little of no difference to malignancy (RR 1.22, 95% CI 0.42 to 3.53; low certainty) and may make little of no difference to death (RR 1.16, 95% CI 0.71 to 1.90; moderate certainty).

AUTHORS' CONCLUSIONS

CNI avoidance increased acute rejection and CNI withdrawal increases acute rejection but reduced graft loss at least over the short-term. Low dose CNI with induction regimens reduced acute rejection and graft loss with no major adverse events, also in the short-term. The use of mTOR-I reduced CMV infections but increased the risk of acute rejection. These conclusions must be tempered by the lack of long-term data in most of the studies, particularly with regards to chronic antibody-mediated rejection, and the suboptimal methodological quality of the included studies.