Conversion from tacrolimus to cyclosporin is associated with a significant improvement of glucose metabolism in patients with new-onset diabetes mellitus after renal transplantation

Novel management of diabetes in kidney transplantation

PURPOSE OF REVIEW

Posttransplant diabetes mellitus (PTDM) is a prevalent complication in kidney transplant recipients, and has been associated with worse short-term and long-term outcomes.

RECENT FINDINGS

While hyperglycemia is frequently seen in the early posttransplant period because of surgical stress, infection, and use of high-dose steroids, the diagnosis of PTDM should be established after patients are clinically stable and on stable maintenance immunosuppression. In the early posttransplant period, hyperglycemia is typically treated with insulin, and pilot data have suggested potential benefit of lower vs. higher glycemic targets in this setting. Growing data indicate lifestyle modifications, including dietary interventions, physical activity, and mitigation of obesity, are associated with improved posttransplant outcomes. While there are limited data to support a first-line antidiabetic medication for PTDM, more established pharmacotherapies such as sulfonylureas, meglitinides, and dipetidyl peptidase IV inhibitors are commonly used. Given recent trials showing the benefits of sodium-glucose cotransporter 2 inhibitors and glucagon-like peptide 1 receptor agonists upon kidney outcomes in nontransplant patients, further study of these agents specifically in kidney transplant recipients are urgently needed.

SUMMARY

Increasing evidence supports a multidisciplinary approach, including lifestyle modification, obesity treatment, judicious immunosuppression selection, and careful utilization of novel antidiabetic therapies in PTDM patients.

Effect of cyclosporine, tacrolimus and sirolimus on cellular senescence in renal epithelial cells

INTRODUCTION

In transplantation medicine calcineurin inhibitors (CNI) still represent the backbone of immunosuppressive therapy. The nephrotoxic potential of the CNI Cyclosporine A (CsA) and Tacrolimus (FK506) is well recognized and CNI not only have been linked with toxicity, but also with cellular senescence which hinders parenchymal tissue regeneration and thus may prime kidneys for subsequent insults. To minimize pathological effects on kidney grafts, alternative immunosuppressive agents like mTOR inhibitors or the T-cell co-stimulation blocker Belatacept have been introduced.

METHODS

We compared the effects of CsA, FK506 and Sirolimus on the process of cellular senescence in different human renal tubule cell types (HK2, RPTEC). Telomere length (by real time PCR), DNA synthesis (by BrdU incorporation), cell viability (by Resazurin conversion), gene expression (by RT-PCR), protein (by western blotting), Immuncytochemistry and H₂O₂ production (by Amplex Red® conversion) were evaluated.

RESULTS

DNA synthesis was significantly reduced when cells were treated with cyclosporine but not with tacrolimus and sirolimus. Resazurin conversion was not altered by all three immunosuppressive agents. The gene expression as well as protein production of the cell cycle inhibitor p21 (CDKN1A) but not p16 (CDKN2A) was significantly induced by cyclosporine compared to the other two immunosuppressive agents when determined by western blotting an immuncytochemistry. Relative telomere length was reduced and hydrogen peroxide production increased after treatment with CsA but not with FK506 or sirolimus.

CONCLUSION

In summary, renal tubule cells exposed to CsA show clear signs of cellular senescence where on the contrary the second calcineurin inhibitor FK506 and the mTOR inhibitor sirolimus are not involved in such mechanisms. Chronic renal allograft dysfunction could be in part triggered by cellular senescence induced by immunosuppressive medication and the choice of drug could therefore influence long term outcome. Tacrolimus and Sirolimus are equally effective in avoiding cellular senescence compared to cyclosporine at least in parts due to a lack of induction of reactive oxygen species.

Kidney transplantation in obese patients

The World Health Organization estimated that in 2014, over 600 million people met criteria for obesity. In 2011, over 30% of individuals undergoing kidney transplant had a body mass index (BMI) 35 kg/m² or greater. A number of recent studies have confirmed the relationship between overweight/obesity and important comorbidities in kidney transplant patients. As with non-transplant surgeries, the rate of wound and soft tissue complications are increased following transplant as is the incidence of delayed graft function. These two issues appear to contribute to longer length of stay compared to normal BMI. New onset diabetes after transplant and cardiac outcomes also appear to be increased in the obese population. The impact of obesity on patient survival after kidney transplantation remains controversial, but appears to mirror the impact of extremes of BMI in non-transplant populations. Early experience with (open and laparoscopic) Roux-en-Y gastric bypass and laparoscopic sleeve gastrectomy support excellent weight loss (in the range of 50%-60% excess weight lost at 1 year), but experts have recommended the need for further studies. Long term nutrient deficiencies remain a concern but in general, these procedures do not appear to adversely impact absorption of immunosuppressive medications. In this study, we review the literature to arrive at a better understanding of the risks related to renal transplantation among individuals with obesity.

Pathogenesis and management of FK506- and CsA-induced post-transplant diabetes mellitus: Similarities and differences

Tacrolimus (FK506) and cyclosporine (CsA) are clinically commonly used immunosuppressive agents, and both of them belong to calcineurin inhibitors. FK506 is more excellent in anti-rejection therapy. They are similar in pharmacological mechanism, but FK506 is more likely to induce post-transplant diabetes mellitus than CsA. This paper analyzes and compares the similarities and differences in the pathogenesis and management between FK506- and CsA-induced post-transplant diabetes mellitus.

The importance of different immunosuppressive regimens in the development of posttransplant diabetes mellitus

Solid-organ transplantation is the optimal long-term treatment for most patients with end-stage organ failure. After solid-organ transplantation, short-term graft survival significantly improved (1). However, due to chronic allograft nephropathy and death with functioning graft, long-term survival has not prolonged remarkably (2). Posttransplant immunosuppressive medications consist of one of the calcineurin inhibitors in combination with mycophenolate mofetil (MMF) or azathioprine (Aza) and steroids. All of them have different adverse effects, among which posttransplant diabetes mellitus (PTDM) is an independent risk factor for cardiovascular (CV) events and infections causing the death of many transplant patients and it may directly contribute to graft failure (3). According to the criteria of the American Diabetes Association (4), diabetes mellitus (DM) is defined by symptoms of diabetes (polyuria and polydipsia and weight loss) plus casual plasma glucose concentration ≥ 11.1 mmol/L or fasting plasma glucose (FPG) ≥ 7.0 mmol/L or 2-h plasma glucose level ≥ 11.1 mmol/L following oral glucose tolerance test (OGTT). This metabolic disorder occurring as a complication of organ transplantation has been recognized for many years. PTDM, which is a combination of decreased insulin secretion and increased insulin resistance, develops in 4.9/15.9% of liver transplant patients, in 4.7/11.5% of kidney recipients, and in 15/17.5% of heart and lung transplants [cyclosporine A (CyA)/tacrolimus (Tac)-based regimen, respectively] (5). Risk factors of PTDM can be divided into non-modifiable and modifiable ones (6), among which the most prominent is the immunosuppressive therapy being responsible for 74% of PTDM development (7). Emphasizing the importance of the PTDM, numerous studies have determined the long-term outcome. On the basis of these studies, graft and patient survival is tendentiously (8) or significantly (9, 10) decreased for those developing PTDM.

Complications associated with new-onset diabetes after kidney transplantation

New-onset diabetes mellitus after kidney transplantation (NODAT) is widely acknowledged to be associated with increased morbidity and mortality, as well as poor quality of life. Clear evidence links the occurrence of NODAT to accelerated progression of some macrovascular and/or microvascular complications. However, the evidence that some complications commonly attributed to diabetes mellitus occur in the context of transplantation lacks robustness. Certain complications are transplantation-specific and prevalent, but others are not frequently observed or documented. For this reason, it is essential that clinicians are aware of the array of potential complications associated with NODAT in kidney allograft recipients. Rather than simply translating evidence from the general population to the high-risk transplant recipient, this Review aims to provide specific guidance on diabetes-related complications in the context of a complex transplantation environment.

Regression of new-onset diabetes mellitus after conversion from tacrolimus to cyclosporine in liver transplant patients: results of a pilot study

INTRODUCTION

New-onset diabetes mellitus (NODM) has important implications for long-term outcome following liver transplantation.

AIM

To evaluate the impact of conversion from tacrolimus to cyclosporine in liver transplant patients presenting NODM.

METHOD

In a 12-month pilot study, 39 liver transplant patients with NODM were converted from tacrolimus to cyclosporine. Most patients (59%) were receiving antidiabetic therapy (18% insulin, 41% oral) and all patients had received dietary advice prior to the study.

RESULTS

At month 12, NODM had significantly resolved (FBG<7 mmol/L without treatment) in 36% of patients (95% CI 20.8-51.0%). In the 16 patients not receiving antidiabetic drugs at baseline, mean FBG decreased from 8.1 mmol/L to 6.6 mmol/L (P=0.008) and mean HbA(1c) decreased from 6.4 to 6.0% (P=0.05). Steroids were stopped rapidly in the nine patients receiving steroids at inclusion but NODM resolution was observed in only one of these nine patients. No significant factors were identified that could have affected NODM resolution. There were three episodes of biopsy-proven acute rejection (7.7%), no graft losses and one death. Overall, cyclosporine tolerance was good with no significant change in creatinine clearance at month 12. Total cholesterol increased from 4.6 mmol/L to 5.1 mmol/L (P<0.001).

CONCLUSIONS

These results suggest that liver transplant patients with NODM may benefit from conversion to cyclosporine from tacrolimus through improved glucose metabolism. Confirmation in a prospective, randomized comparative study is required.

Risk factors for new-onset diabetes after kidney transplantation

New-onset diabetes after transplantation, a common complication following kidney transplantation, is associated with adverse patient and graft outcomes. Our understanding of the risk factors associated with this metabolic disorder is improving and both transplantation-specific and nonspecific factors are clearly involved. Knowledge of these risk factors is important so that clinicians can implement pre-emptive risk stratification strategies and to guide therapeutic, risk-attenuation approaches in patients who develop transplant-associated hyperglycemia. In this Review, we explore the current understanding of the diverse range of risk factors that contribute to abnormal glucose metabolism after transplantation, with the aim of helping to guide clinical decision-making using appropriate risk stratification.

Immunosuppressive drugs in kidney transplantation: impact on patient survival, and incidence of cardiovascular disease, malignancy and infection

Renal transplant recipients have increased mortality rates when compared with the general population. The new immunosuppressive drugs have improved short-term patient survival up to 95% at 1-2 years, but these data have to be confirmed in long-term follow-up. Furthermore, no particular regimen has proved to be superior over others with regard to patient survival. Cardiovascular diseases are the most common cause of mortality in renal transplant recipients and while no immunosuppressive drug has been directly associated with cardiovascular events, immunosuppressive drugs have different impacts on traditional risk factors. Corticosteroids and ciclosporin are the agents with the most negative impact on weight gain, blood pressure and lipids. Tacrolimus increases the risk of new-onset diabetes mellitus. Sirolimus and everolimus have the most impact on risk factors for post-transplant hyperlipidaemia. Modifications in immunosuppression could improve the cardiovascular profile but there is little evidence regarding the beneficial effects of these changes on patient outcomes. Malignancies are also an increasing cause of mortality, overtaking cardiovascular disease in some series. Induction therapy, azathioprine and calcineurin inhibitors (CNIs) are probably the immunosuppressive agents most linked with post-transplant malignancies. Mycophenolate mofetil (MMF) has no negative impact on the incidence of malignancies. Target of rapamycin (mTOR) inhibitors have antioncogenic properties and they are associated with a lower incidence of malignancies. In addition, these agents have been recommended for use to decrease the dose or withdrawal of CNIs in patients with malignancies. Infections are still an important cause of morbidity and mortality in renal transplant recipients. Some immunosuppressive agents such as MMF increase the incidence of cytomegalovirus infection and the need for prophylactic measures in risk recipients. The use of potent immunosuppressive therapy has resulted in the appearance of BK virus nephropathy, which progresses to graft failure in a high percentage of patients. Although first associated with tacrolimus and MMF immunosuppression, recent data suggest that BK nephropathy appears with any kind of triple therapy. In conclusion, reducing risk factors for patient death should be a major target to improve outcomes after renal transplantation. Effort should be made to control cardiovascular diseases, malignancies and infections with improved use of immunosuppressive drugs. Preliminary results with belatacept suggest its safety and efficacy, and open new perspectives in the immunosuppression of de novo renal transplant recipients.

KDIGO clinical practice guideline for the care of kidney transplant recipients

The 2009 Kidney Disease: Improving Global Outcomes (KDIGO) clinical practice guideline on the monitoring, management, and treatment of kidney transplant recipients is intended to assist the practitioner caring for adults and children after kidney transplantation. The guideline development process followed an evidence-based approach, and management recommendations are based on systematic reviews of relevant treatment trials. Critical appraisal of the quality of the evidence and the strength of recommendations followed the Grades of Recommendation Assessment, Development, and Evaluation (GRADE) approach. The guideline makes recommendations for immunosuppression, graft monitoring, as well as prevention and treatment of infection, cardiovascular disease, malignancy, and other complications that are common in kidney transplant recipients, including hematological and bone disorders. Limitations of the evidence, especially on the lack of definitive clinical outcome trials, are discussed and suggestions are provided for future research.

Increasing incidence of new-onset diabetes after transplant among pediatric renal transplant patients

BACKGROUND

Risk of new-onset diabetes after transplant (NODAT) is well characterized for adults but much less understood in pediatric transplant. This study examines the incidence and risk factors of NODAT in pediatric renal transplant patients.

METHODS

The incidence of NODAT over the first 3 years after transplant was examined with the United States Renal Data System data for primary renal transplant recipients (ages 0-21 years, transplanted between 1995 and 2004) with Medicare primary. Patients had no evidence of diabetes before transplant. We estimated the cumulative incidence rate and used Cox proportional hazards regression to identify the risk factors for NODAT. Propensity scores were calculated for immunosuppression choice to adjust for potential confounding factors.

RESULTS

Two thousand one hundred sixty-eight recipients with valid immunosuppression records and without pretransplant evidence of diabetes were included. Unadjusted, cumulative NODAT incidence at 3 years posttransplant was 7.1%. Significant factors for increased risk of NODAT included cytomegalovirus D+/R- serostatus (adjusted hazard ratio [aHR]=1.60), age 13 to 18 years (aHR=2.18), age 19 to 21 years (aHR=2.60), body mass index more than or equal to 30 kg/m (aHR=2.17), and use of tacrolimus (aHR=1.51). We failed to find any significant relationships between NODAT and graft failure or death.

CONCLUSIONS

Although the incidence of NODAT among patients aged 0 to 21 years is lower than that for adult patients, it is higher than suggested by earlier research and may represent an increase over time. The lack of association between NODAT and graft or failure death has important implications for posttransplant care. A clearer understanding of risk factors can help guide posttransplant monitoring and clinical decision making.

Immunosuppressive agents: effects on glucose and lipid metabolism

Immunosuppressive therapies are critical elements in successful organ transplantation. Although immunosuppressant drugs are essential in preventing graft rejection and graft maintenance after transplantation, their use is complicated by adverse effects, many being detrimental to graft and even patient long-term survival. Commonly used agents are associated with dysregulated glucose metabolism and dyslipidemia. This article focuses on the effects of immunosuppressive agents on glucose and lipid metabolism. Adrenal effects of these drugs, where known, also are discussed.

Conversion from tacrolimus to cyclosporine could improve control of posttransplant diabetes mellitus after renal transplantation

Posttransplant diabetes mellitus (PTDM) occurs in approximately 15% to 20% of renal transplant patients. It has important clinical implications for graft function and survival. Anticalcineurin drugs are associated with an increased risk of developing PTDM. There is a little evidence that conversion from tacrolimus to cyclosporine (CsA)-based immunosuppression improves glucose metabolism and reverses diabetes. This prospective study included nine renal transplant patients (mean age of 34 +/- 20) with PTDM under immunosuppression with tacrolimus. Five were switched directly to CsA and the other four (glycemia > 250 mg/dL) required insulin and were simultaneously switched to CsA. Basal blood levels of tacrolimus were 7.9 +/- 1.9 ng/dL. Conversion was associated with an early, significant improvement of glycemia and HbA1c blood levels (P < .01). At the end of the follow-up, the glycemia (105 +/- 20 mg/dL) and Hb1Ac (5.1 +/- 0.4 mg/dL) were normal. Insulin was discontinued between 3 and 6 months in all patients who required it at the beginning. Cholesterol did not change significantly and triglycerides decreased significantly (basal 210 +/- 85 mg/dL, at 12 months 125 +/- 29, P < .01). Graft function was stable with a mean serum creatinine of 1.7 +/- 0.2 mg/dL. CsA blood levels remained stable during all follow-up periods (P = NS). There were neither episodes of acute rejection nor secondary effects related to the medication. In summary, renal transplant patients receiving tacrolimus who develop PTDM may display better control of hyperglycemia by a switch to CsA.

Immunosuppressive drug-induced diabetes

Post-transplant diabetes mellitus (PTDM) has emerged as a major adverse effect of immunosuppressive drugs (ISD). As recipients of organ transplants survive longer, the complications of diabetes mellitus have assumed greater importance. The predominant factor for causing PTDM by corticosteroids seems to be the aggravation of insulin resistance, however several studies have displayed deleterious effects on insulin secretion and beta-cells. Calcineurin inhibitors induce PTDM by a number of mechanisms, including decreased insulin secretion and a direct toxic effect on the pancreatic beta-cells. Recent in vitro studies stress on the increased apoptosis of beta-cells when exposed to these drugs. Studies involving other immunosuppressive agents (mycophenolate mofetil [MMF], sirolimus) are scarcer and lead to conflicting results, while daclizumab seems to have a neutral effect. Clinical studies have consistently shown a greater potential of tacrolimus to induce PTDM compared with cyclosporine. Reducing PTDM incidence is a feasible goal while using corticosteroid-sparing regimens and/or lower tacrolimus trough levels. In patients developing PTDM, conversion from tacrolimus to cyclosporine could improve or reverse glucose tolerance abnormalities. In the absence of well-designed studies in this specific indication, treatment of PTDM is based on the same principles as type 2 diabetes mellitus. Thiazolidinediones do not display any pharmacological interaction with calcineurin inhibitors, but their safety and efficacy in PTDM need to be confirmed in large-scale randomized trials. Use of sulfonylureas has to be cautious regarding the suspected interaction of some of them with calcineurin inhibitors. If needed, insulin regimens have to be adapted in patients who display the particular glycaemic profile of corticosteroid-induced diabetes. Incretin-based therapies, due to their specific action on beta-cell apoptosis and proliferation, raise promises that have to be confirmed in clinical studies. Until methods for inducing specific graft tolerance become available, immunosuppressive regimens should be tailored to the individual patient on the basis of predictive criteria for the development of PTDM.

Maintenance immunosuppression regimens: conversion, minimization, withdrawal, and avoidance

A wide choice of drug combinations is available to clinicians for immunosuppression regimens for their kidney transplant patients. Although many protocols have minimized early graft loss, the optimal long-term regimen is unknown. Recent studies clearly showed that cardiovascular death is now the leading cause of graft loss. Strategies must be developed that address this risk while keeping immunologic events low. Transplant physicians have focused on exploring regimens that minimize or avoid the use of corticosteroids. Studies also have started to explore protocols that minimize calcineurin inhibitor therapy.

Current and evolving immunosuppressive regimens in kidney transplantation

The advent of novel immunosuppressive agents with increased potency now offers multiple treatment options for transplant physicians. However, variable efficacy, drug-drug interactions, and adverse effects associated with long-term immunosuppression continue to complicate the clinical management of kidney transplant recipients. Currently, investigators are challenged to develop regimens that take into account not only efficacy, but also dosing, monitoring, safety, and patient quality of life. Recent research has focused on evaluating new combinations of approved agents that seek to improve outcomes by improving control of immunologic events with fewer complications. This article reviews current practice and recent studies to give all health care providers who manage kidney transplant recipients a better understanding of current regimens and general trends in immunosuppressive therapy.