CARDIOVASCULAR RISK PROFILE AFTER CONVERSION FROM CYCLOSPORINE A TO TACROLIMUS IN STABLE RENAL TRANSPLANT RECIPIENTS

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.

Optimization of de novo belatacept-based immunosuppression administered to renal transplant recipients

Kidney transplant recipients administered belatacept-based maintenance immunosuppression present with a more favorable metabolic profile, reduced incidence of de novo donor-specific antibodies (DSAs), and improved renal function and long-term patient/graft survival relative to individuals receiving calcineurin inhibitor (CNI)-based immunosuppression. However, the rates and severity of acute rejection (AR) are greater with the approved belatacept-based regimen than with CNI-based immunosuppression. Although these early co-stimulation blockade-resistant rejections are typically steroid sensitive, the higher rate of cellular AR has led many transplant centers to adopt immunosuppressive regimens that differ from the approved label. This article summarizes the available data on these alternative de novo belatacept-based maintenance regimens. Steroid-sparing, belatacept-based immunosuppression (following T cell-depleting induction therapy) has been shown to yield AR rates comparable to those seen with CNI-based regimens. Concomitant treatment with belatacept plus a mammalian target of rapamycin inhibitor (mTORi; sirolimus or everolimus) has yielded AR rates ranging from 0 to 4%. Because the optimal induction agent and number of induction doses; blood levels of mTORi; and dose, duration, and use of corticosteroids have yet to be determined, larger prospective clinical trials are needed to establish the optimal alternative belatacept-based regimen for minimizing early cellular AR occurrence.

Effect of Posttransplant Diabetes Mellitus on Graft Loss After Living-Donor Kidney Transplant at a Single Institution

BACKGROUND

This study aimed to evaluate predictive factors for graft loss in patients who received kidney transplantation (KT) from living kidney donors (LKDs) at a single institute in Japan.

METHODS

Our study focused on patients with end-stage renal disease who underwent KT from LKDs and were followed up for at least 1 year after surgery. The primary end point was graft survival (GS). GS after KT was analyzed using the Kaplan-Meier method. GS according to subgroup classification was analyzed using the log-rank test. A multivariate analysis was performed using a Cox proportional hazard model.

RESULTS

The median follow-up period was 105.5 months after KT. The 5- and 10-year GS rates were 97.8% and 96.0% in KT recipients (KTRs) without posttransplant diabetes mellitus (PTDM) and 89.9% and 63.2% in those with PTDM, respectively. The rate of graft loss was significantly higher in KTRs with PTDM than in those without PTDM (P < .001). Of the KTRs whose diabetes mellitus (DM) was cured after KT, those who underwent dialysis because of diabetic nephropathy had no graft loss. In the multivariate analysis, the serum creatinine level at 1 month after KT, PTDM, and human leukocyte antigen mismatches were significantly associated with graft loss after KT.

CONCLUSIONS

In this study, the rate of graft loss in KTRs with PTDM was significantly higher than that of KTRs without PTDM. However, among KTRs whose DM was cured after KT, those who underwent dialysis because of diabetic nephropathy had no graft loss.

Management of dyslipidemia in adult solid organ transplant recipients

Solid organ transplantation (SOT) has revolutionized treatment of end-stage disease. Improvements in the SOT continuum of care have unmasked a significant burden of cardiovascular disease, manifesting as a leading cause of morbidity and mortality. Although several risk factors for development of post-transplant cardiovascular disease exist, dyslipidemia remains one of the most frequent and modifiable risks. An important contributor to dyslipidemia in SOT recipients is the off-target metabolic effects of immunosuppressive medications, which may alter lipoproteins and their metabolism. Dyslipidemia management is paramount as lipid-lowering therapy with statins has demonstrated reductions in graft vasculopathy, decreased rejection rates, and improved survival. Several nonstatin medication options are available, but data supporting their benefit in the SOT population are minimal, typically extrapolated from studies in the general population. Further compounding dyslipidemia management is the complex interplay of drug interactions between lipid-lowering and immunosuppressant medications, which can result in serious toxicity and/or therapeutic failure.

Diabetes and other endocrine-metabolic abnormalities in the long-term follow-up of pancreas transplantation

Pancreas transplantation (PTX) has been demonstrated to restore long-term glucose homeostasis beyond what can be achieved by intensive insulin therapy or islet transplants. Moreover, PTX has been shown to decrease the progression of the chronic complications of diabetes. However, PTX patients require chronic use of immunosuppressive drugs with potential side effects. The long-term follow-up of PTX patients demands special care regarding metabolic deviations, infectious complications, and chronic rejection. Diabetes and other endocrine metabolic abnormalities following transplantation are common and can increase morbidity and mortality. Previous recipient-related and donor-related factors, as well as other aspects inherent to the transplant, act together in the pathogenesis of those abnormalities. Early recognition of these disturbances is the key to timely treatment; however, adequate tools to achieve this goal are often lacking. In a way, the type of PTX procedure, whether simultaneous pancreas kidney or not, seems to differentially influence the evolution of endocrine and metabolic abnormalities. Further studies are needed to define the best approach for PTX patients. This review will focus on the most common endocrine metabolic disorders seen in the long-term management of PTX: diabetes mellitus, hyperlipidemia, and bone loss. The authors here cover each one of these endocrine topics by showing the evaluation as well as proper management in the follow-up after PTX.

Characteristics of low-density and high-density lipoprotein subclasses in pediatric renal transplant recipients

Renal transplant recipients often suffer from dyslipidemia which is one of the principal risk factors for cardiovascular disease. This study sought to determine characteristics of high-density lipoprotein (HDL) and low-density lipoprotein (LDL) particles and their associations with carotid intima-media thickness (cIMT) in a group of pediatric renal transplant recipients. We also examined the influence of immunosuppressive therapy on measured LDL and HDL particle characteristics. HDL size and subclass distribution were determined using gradient gel electrophoresis, while concentrations of small, dense LDL (sdLDL)-cholesterol (sdLDL-C) and sdLDL-apolipoprotein B (sdLDL-apoB) using heparin-magnesium precipitation method in 21 renal transplant recipients and 32 controls. Renal transplant recipients had less HDL 2b (P < 0.001), but more HDL 3a (P < 0.01) and 3b (P < 0.001) subclasses. They also had increased sdLDL-C (P < 0.01) and sdLDL-apoB (P < 0.05) levels. The proportion of the HDL 3b subclasses was a significant predictor of increased cIMT (P < 0.05). Patients treated with cyclosporine had significantly higher sdLDL-C and sdLDL-apoB concentrations (P < 0.05) when compared with those on tacrolimus therapy. Pediatric renal transplant recipients have impaired distribution of HDL and LDL particles. Changes in the proportion of small-sized HDL particles are significantly associated with cIMT. Advanced lipid testing might be useful in evaluating the effects of immunosuppressive therapy.

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.

Low levels of high-density lipoprotein cholesterol: an independent risk factor for late adverse cardiovascular events in renal transplant recipients

Long-term kidney transplant graft and patient survival is often limited by cardiovascular (CV) disease. Risk factors for CV disease such as diabetes, hypertension and elevated low-density lipoprotein levels are well documented; however, the impact of low levels of high-density lipoprotein (HDL) has not been defined. We performed a retrospective chart review of 324 consecutive renal transplant recipients from 2001 to 2007 to correlate baseline HDL levels with major adverse cardiovascular events (MACEs) defined as a composite of new onset CV illness, cerebral vascular events and peripheral vascular disease. A total of 92 MACEs occurred over a total of 1913 patient years of follow-up. Low HDL cholesterol levels were noted in 58.3% of patients. Compared with those with normal HDL levels, a greater percentage of patients with low HDL levels had post-transplant MACEs (20% vs. 60% respectively) and experienced an increased rate of all cause mortality. Sixty-two percent of all MACEs occurred in patients with low HDL levels. In the low HDL group, the odds ratio for experiencing a MACE was 1.92. Therefore, HDL cholesterol may provide an important new therapeutic target to prevent vascular morbidity and mortality following renal transplantation.

Minimization of calcineurin inhibitors to improve long-term outcomes in kidney transplantation

Long-term outcomes after kidney transplantation remain suboptimal, despite the great achievements observed in recent years with the use of modern immunosuppressive drugs. Currently, the calcineurin inhibitors (CNI) cyclosporine and tacrolimus remain the cornerstones of immunosuppressive regimens in many centers worldwide, regardless of their well described side-effects, including nephrotoxicity. In this article, we review recent CNI-minimization strategies in kidney transplantation, while emphasizing on the importance of long-term follow-up and patient monitoring. Finally, accumulating data indicate that low-dose CNI-based regimens would provide an interesting balance between efficacy and toxicity.

Comparative risk of impaired glucose metabolism associated with cyclosporine versus tacrolimus in the late posttransplant period

New onset diabetes after transplantation (NODAT) and impaired fasting glucose (IFG) are common in kidney transplant recipients (KTRs). Calcinuerin inhibitor (CNI) therapy is a causal risk factor. NODAT is associated with increased mortality and diminished graft survival. We studied the incidence of NODAT and IFG in KTRs before and after a medically indicated switch of CNI therapy from cyclosporine (CsA) to tacrolimus (Tac). The study population consisted of 704 nondiabetic KTRs. Of them, 171 underwent conversion from CsA to Tac (group I) and 533 remained on the CsA since transplantation (Group II). Time-dependent Cox regression and generalized estimating equations were used to account for sequential CNI exposure. NODAT and IFG occurred in 15.2% and 22.1% of group I subjects and 15.6% and 25.8% of group II subjects, respectively (p = 0.90 for NODAT and p = 0.38 for IFG). Accounting for equal follow-up time since conversion from CsA to Tac, the adjusted 5-year NODAT-free survival was 87.4% and 91.4% in group I and group II, respectively (p = 0.90). In conclusion, conversion to Tac, compared to continuous exposure to CsA, carries quantitatively similar risk of impaired glucose metabolism in KTRs in the late posttransplant period.

Calcineurin inhibitors and post-transplant weight gain

AIM

Excessive weight gain that leads to obesity is quite common after kidney transplantation. This is often attributed to immunosuppression. The aim of this retrospective study was to assess the effect of calcineurin inhibitors on post-transplant weight gain.

METHODS

A total of 99 patients were studied. The patients were divided into cyclosporine A (CyA) and tacrolimus (Tac) groups and were evaluated for weight changes and risk factors related to weight gain.

RESULTS

The weights of patients in both groups significantly increased after the sixth month. The median weight gain at 12 months was 3.5 and 8.0 kg compared with pretransplant dry weight in the Tac and CyA groups, respectively. The increases in the CyA group were significant compared with those of the Tac group. The prevalences of obese and overweight patients in both groups did not differ during a 12-month follow-up. The frequencies of diabetes mellitus, hypertension and dyslipidemia were comparable in both groups. The decrease in systolic blood pressure (BP) of the Tac group was significant compared with the decrease in the CyA group at the 12th month. In the 12-month follow-up period, the increases in triglyceride, total- and low-density lipoprotein-cholesterol values of the CyA group were significantly higher than those of the Tac group. The weight change between 0 and 12 months was negatively correlated with pretransplant body mass index (BMI) and positively with cumulative corticosteroid doses, total-cholesterol and BP changes.

CONCLUSION

Only pretransplant BMI, creatinine clearance, CyA usage, being hypertensive and dyslipidemic were independent predictors of weight gain at the 12th month. Our results suggested that the type of immunosuppression may affect post-transplant weight gain.

Immunosuppressive medications, clinical and metabolic parameters in new-onset diabetes mellitus after kidney transplantation

New-onset diabetes after transplantation (NODAT) is a growing concern in transplantation. All modifiable risk factors are not yet identified. We assessed the relationship between baseline clinical and biochemical parameters and NODAT. Eight-hundred and fifty-seven in-Caucasian renal transplant recipients were included. Charts were individually reviewed. The follow-up was 5.3 years (ranges: 0.25-20.8; 5613 patient-years). The incidence of NODAT was 15.0%, 18.4% and 22.0% at 10, 15 and 20 years following transplantation. Age, body mass index (BMI), glucose (all P < 0.0001) and triglycerides [hazard ratio (HR) per 1 mmol/l: 1.44 [1.17-1.77], P = 0.0006] were potent risk factors whereas steroid withdrawal (HR: 0.69 [0.47-1.01], P = 0.0601) reduced the risk. As compared to cyclosporine, sirolimus (HR: 3.26 [1.63-6.49], P = 0.0008) and tacrolimus (HR: 3.04 [2.02-4.59], P < 0.0001) were risk factors for NODAT. The risk of NODAT was comparable for sirolimus (HR: 2.35 [1.06-5.19], P = 0.0350) and tacrolimus (HR: 2.34 [1.46-3.75], P = 0.0004) after adjustments on age, BMI, glucose and steroid withdrawal; however, unlike sirolimus, tacrolimus remained significant after adjustment on triglycerides. The risk of NODAT appeared similar, but its pathophysiology seemed different in sirolimus- and tacrolimus-treated patients; this observation needs confirmation. However, main independent risk factors were age, BMI, initial glucose and triglycerides.

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.

Subclinical inflammation in renal transplant recipients: impact of cyclosporine microemulsion versus tacrolimus

BACKGROUND

Renal insufficiency and renal transplant (RT) provoke a microinflammatory state that leads to increased atherosclerosis. It is not fully known whether calcineurin inhibitors (CNIs) play a role in the inflammation observed in these patients or whether any differences exist between CNIs.

OBJECTIVES

The study aimed to establish differences in the inflammatory state of two groups treated with cyclosporine microemulsion (CyA) or tacrolimus (TC).

PATIENTS AND METHODS

This prospective study included 81 RT patients divided into two groups according to the CNI: CyA group, n = 35 versus TC group, n = 46. The markers of inflammation (MIF) were determined preRT and at 3 and 12 months' postRT: C-reactive protein (CRP), serum amyloid protein A (SAA), interleukin-6 (IL-6), soluble interleukin-2 receptor (sIL-2R), tumor necrosis factor-alpha (TNF-alpha), and pregnancy-associated plasma protein A (PAPP-A). Samples were collected in stable patients in the absence of rejection, active infection, or inflammatory processes.

RESULTS

No significant differences existed between the markers of inflammation in the two treatment groups prior to transplantation. At 3 months' posttransplant, patients treated with CyA showed significantly higher levels of IL-6 (P = .05), SAA (P = .03), and sIL-2R (P = .008) compared with patients treated with TC. These differences were maintained for IL-6 (P = .03) and sIL-2R (P = .027) at 12 months' posttransplant. A multivariate analysis at 3 months showed that only age [OR 10.1; CI (95% 2.6-38.4); P = .001], SAA [OR 4.8; IC (95% 1.4-16.5); P = .015], and sIL-2R [OR 4.9; IC (95% 1.5-16.2); P = .009] were independent predictors of the CNI used. At 12 months, age [OR 3.7; IC (95% 0.9-14.2] and sIL-2R [OR 6.04; IC (95% 1.5-23); P = .006] continued to be independent predictors.

CONCLUSIONS

Patients treated with CyA displayed significantly higher levels of inflammatory markers (IL-6, SAA, sIL-2R) at 3 and 12 months' posttransplantation, independent of age, gender, time on dialysis, diabetes mellitus (preRT and de novo postRT), and renal function measured by serum creatinine.

Early steroid withdrawal in pediatric renal transplant on newer immunosuppressive drugs

Steroids have been a cornerstone in renal transplant immunosuppression. New immunosuppressive drugs have led to protocols using early steroid withdrawal or complete avoidance. A prospective protocol in 23 pediatric renal transplant (ages 2-14 yr) who received decreasing steroid doses stopping at day 7 post-Tx, FK, and MMF were compared with a CsA, AZT, historically matched steroid-based control group. Basiliximab was used in two doses. Anthropometric, biochemical variables, AR rates, and CMV infection were evaluated and compared using Student's t-test and regression analysis. A better growth pattern was seen in steroid withdrawal group. GFR rate and serum glucose were similar in both groups. Total serum cholesterol levels were significantly lower in steroid withdrawal group. The incidence of AR at 12 months was 4.3% in steroid withdrawal group vs. 8.6% in steroid-based group (p = ns). No difference in CMV infection was observed. Hemoglobin levels were low during the first months in both groups; reached normal values after six months. SBP became higher at 12 months in steroid-based group. Patient and graft survival was 98% in both groups at one-yr post-transplant. Early steroid withdrawal was efficacious, safe, and did not increase risk of rejection, preserving optimal growth, renal function, and reducing cardiovascular risk factors.

The mammalian target of rapamycin regulates lipid metabolism in primary cultures of rat hepatocytes

The mammalian target of rapamycin (mTOR) is a conserved serine-threonine kinase that regulates cell growth and metabolism in response to nutrient signals. However, the specific involvement of mTOR in regulation of energy metabolism is poorly understood. To determine if signaling via mTOR might be directly involved in regulation of fatty acid metabolism in hepatocytes, we performed studies with rapamycin, a specific inhibitor of mTOR. Rapamycin-mediated inhibition of mTOR (18-48 hours) increased oxidation of exogenous fatty acids (46%-100%, respectively). In addition, esterification of exogenous fatty acids and de novo lipid synthesis were reduced (40%-60%, respectively). Consistent with inhibition of lipogenic pathways, rapamycin decreased expression of genes encoding acetyl-coenzyme A carboxylase I and mitochondrial glycerol phosphate acyltransferase. Non-insulin-dependent glucose transport and glycogen synthesis were decreased by 20% to 30%, whereas glucose utilization was unaffected by rapamycin. The data suggest that the hyperlipidemia observed with the drug in vivo is likely not the result of enhanced hepatic synthesis, but rather of delayed peripheral clearance. However, these results are consistent with the idea that mTOR may play a significant role, not only in "energy sensing," but also in regulation of energy production through profound effects on hepatic fatty acid metabolism.

A comparison of the effects of C2-cyclosporine and C0-tacrolimus on renal function and cardiovascular risk factors in kidney transplant recipients

BACKGROUND

There are few data directly comparing the effects of two-hour postingestion monitored cyclosporine (C2-CsA) vs. trough-monitored tacrolimus (C0-Tac) on renal function and cardiovascular risk factors.

METHODS

We studied 378 (202 C2-CsA vs. 176 C0-Tac) incident kidney transplant recipients in Toronto, Canada, from August 1, 2000 and December 31, 2003. Outcomes included changes in estimated glomerular filtration rate (eGFR at 1 and 6 months by modification of diet in renal disease four-variable equation), mean arterial pressure (MAP), total cholesterol (TC), and new-onset diabetes mellitus (NODM) at six months posttransplant. The independent effect of treatment/monitoring strategies on continuous outcomes and time-to-NODM was modeled using linear and Cox regression, respectively.

RESULTS

Mean eGFR was 59.5 vs. 62.9 ml/min at one month and 50.6 vs. 61.2 ml/min at six months for C2-CsA vs. C0-Tac, respectively. Multiple linear regression revealed the slope of eGFR to be 0.93 ml/min/month lower in C2-CsA patients. This was equivalent to an adjusted average eGFR difference of 4.64 ml/min between months one and six posttransplant. There was no significant difference in average MAP and TC. In a stepwise multivariable Cox model and a propensity score analysis, there was no significant association between the type of treatment/monitoring strategy and time-to-NODM.

CONCLUSIONS

There was a greater decline in eGFR for patients on C2-CsA (vs. C0-Tac) between one and six months posttransplant. However, MAP, TC, and the risk of NODM were comparable in both treatment/monitoring groups. The long-term impact of short-term reductions in eGFR as a function of the type of treatment/monitoring strategy requires further study.

Conversion From Cyclosporine Microemulsion to Tacrolimus in Stable Kidney Transplant Patients With Hypercholesterolemia Is Related to an Improvement in Cardiovascular Risk Profile: A Prospective Study

The aim of this prospective multicenter study was to evaluate the effect of conversion from cyclosporine (CsA) to tacrolimus (Tac) on cardiovascular risk factors in stable kidney transplant patients with hyperlipidemia. Twenty-six patients were switched from CsA to Tac at 81.7 +/- 44.4 months after transplantation. Tac was started at 0.15 mg/kg/d. Patient outcomes were evaluated up to 6 months after conversion. Significant reductions were seen in systolic blood pressure (143 +/- 13 baseline to 136 +/- 9 mm Hg at 6 months, P = .026) as well as the need for antihypertensive medication, with no changes in diastolic blood pressure. There was a significant reduction in total cholesterol (247 +/- 41 to 221 +/- 35 mg/dL, P = .003), low-density lipoprotein cholesterol (150 +/- 24 to 127 +/- 27 mg/dL, P = .001), total cholesterol/high-density lipoprotein (HDL) cholesterol ratio (4.9 +/- 1.9 to 3.9 +/- 1, P = .02), and triglyceride levels (228 +/- 175 to 148 +/- 71 mg/dL, P = .026). No significant modifications in HDL cholesterol, Apo A1 and Apo-B levels, or in the need for lipid-lowering medication were observed. Glucose levels did not change, but an increase in HbAC1 took place (5.8 +/- 1.1 to 6.2 +/- 1, P = .002). In men Framingham risk score significantly decreased from 11.5 +/- 11.3 to 8.4 +/- 7.2. (P = .0023). In conclusion, elective conversion from CsA to Tac in stable kidney transplant patients with hyperlipidemia was related to an improved blood pressure and lipid profile, both suggesting a decrease in the estimated 10-year coronary heart disease risk in men.

Subclinical Inflammation and Prothrombotic State in Heart Transplant Recipients: Impact of Cyclosporin Microemulsion vs. Tacrolimus

BACKGROUND

Subclinical inflammation is related to adverse events in patients with coronary artery disease. In the present study, we determined the changes in hemostatic parameters and inflammatory markers in a large cohort of dyslipidemic cardiac transplant recipients compared with dyslipidemic healthy controls, and the effect of cyclosporin microemulsion (CsA) vs. tacrolimus immunoprophylaxis on these parameters.

METHODS

Stable cardiac transplant recipients (n=129) aged 56.7+/-10.1 years, 79+/-42 months postcardiac transplantation, and 26 mildly dyslipidemic healthy control subjects had serum measurements for lipids and lipoproteins, hemostatic parameters, and selected inflammatory markers. Transplant recipients were randomized to either continuation of CsA maintenance or conversion to tacrolimus immunoprophylaxis and were reassessed after six months.

RESULTS

CsA-maintained cardiac transplant recipients exhibited a significant elevation in Factor VIII, Von Willebrand factor, fibrinogen and PAI-I compared with healthy control subjects (all P<0.05). Similarly, cardiac transplant patients yielded a significantly elevated C-reactive protein (CRP) (4.11+/-6.25 [transplant group (TX)] vs. 2.09+/-2.21 mg/L [control group (CTL)]; P=0.0195), and homocysteine (19.2+/-8.8 [TX] vs. 9.70+/-2.45 microM [CTL]; P<0.001). VCAM, ICAM, E- and P-selectins were also significantly higher in transplant patients than in controls (all P<0.05). The conversion from CsA to tacrolimus resulted in a significant decrease in uric acid, total- and LDL-cholesterol, apolipoprotein B, creatinine, and homocysteine levels (all P<0.05).

CONCLUSIONS

Stable long-term CsA-maintained cardiac transplant patients exhibit a significant and general increase in hemostatic parameters and markers for subclinical inflammation. Tacrolimus conversion improved the patient lipid profile and decreased serum creatinine, uric acid, and homocysteine without any significant effect on the other markers.

Effect of Atorvastatin Therapy and Conversion to Tacrolimus on Hypercholesterolemia and Endothelial Dysfunction After Renal Transplantation

BACKGROUND

Hypercholesterolemia is a frequent complication in renal transplant patients treated with cyclosporine A (CsA). Whether it is preferable to treat hypercholesterolemia with statins or to switch patients from CsA to tacrolimus (TRL) has not been investigated.

METHODS

Twelve CsA-treated kidney transplant recipients with hypercholesterolemia were successively crossed over from CsA alone to: CsA plus atorvastatin; TRL alone; and TRL plus atorvastatin. Total cholesterol (C), Low density lipoprotein (LDL)-C, high density lipoprotein (HDL)-C, LDL and HDL alpha-tocopherol content, lag-time of LDL oxidation, plasma levels of oxidized LDL and the percentage of small dense LDL were assayed at the end of each treatment period. Endothelial function was assessed by high resolution ultrasound measurement of flow-mediated brachial artery vasodilatation (FMD).

RESULTS

Atorvastatin therapy was more efficient in reducing total cholesterol and LDL-C levels than conversion from CsA to TRL. Combining TRL with atorvastatin further reduced LDL-C levels as compared to TRL alone, but was no more efficient than the CsA-statin combination. Neither atorvastatin therapy nor conversion to TRL significantly changed the proportion of dense LDL, lipoprotein alpha-tocopherol contents or the lag time of LDL oxidation. Addition of atorvastatin to CsA increased FMD from 4.0+/-1.8% to 6.5+/-4.0% (P<0.05 vs. CsA). Conversion from CsA to TRL caused a slight improvement in FMD (5.1+/-2.1%, P<0.05 vs. CsA). Adding atorvastatin to TRL had no detectable effect on FMD (5.5+/-2.3%, P=NS vs. TRL).

CONCLUSIONS

Atorvastatin was more efficient in reducing total and LDL cholesterol levels of CsA-treated renal transplant patients than conversion to TRL and significantly improved endothelial dysfunction.

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.

Relative risk of new-onset diabetes during the first year after renal transplantation in patients receiving tacrolimus or cyclosporine immunosuppression

Clinical trials have consistently shown a higher incidence of new-onset diabetes mellitus with tacrolimus than cyclosporine. However, in protocol-driven studies steroid doses are comparable in both treatment arms, while in clinical practice steroid dose used in conjunction with tacrolimus or cyclosporine may differ. This retrospective study analysed renal transplant recipients without pre-existing diabetes receiving tacrolimus (n = 100) or cyclosporine (n = 100) for whom one-year follow-up data were available. Diabetes was defined as use of insulin or oral hypoglycemic agents; fasting glucose >6.9 mmol/L; or non-fasting glucose >11 mmol/L on three consecutive occasions. Tacrolimus-treated patients were significantly older than cyclosporine-treated patients (49 +/- 14 vs. 44 +/- 13 yr, p < 0.05) and received a significantly lower cumulative dose of corticosteroids over the first three months post-transplant (1284 +/- 379 vs. 1714 +/- 486 mg, p < 0.0001). At 3, 6, 9 and 12 months significantly more tacrolimus-treated patients had new-onset diabetes than cyclosporine- treated patients. At 12 months, 18 patients receiving tacrolimus and two receiving cyclosporine had diabetes (p < 0.0001). There was a clear relationship between age and incidence of new-onset diabetes at three months in the tacrolimus cohort. After stratifying patients by age group, the frequency of diabetes was significantly higher with tacrolimus than with cyclosporine in patients aged 40-60 yr [8/46 (17.4%) vs. 2/48 (4.2%), p < 0.05] and >60 yr [9/28 (32.1%) vs. 0/14 (0%), p < 0.05]. The mean tacrolimus trough level during the first three months was similar in patients with diabetes (13.1 +/- 2.3 ng/mL) or without diabetes (13.0 +/- 2.8 ng/mL, n.s.). These results indicate that new-onset diabetes is strongly and significantly associated with tacrolimus vs. cyclosporine in renal transplant recipients, even when steroid dosing is lower with tacrolimus.

Slowing the progression of chronic allograft nephropathy by conversion from cyclosporine to tacrolimus: a randomized controlled trial

BACKGROUND

Chronic allograft nephropathy (CAN) is a multifactorial process with immunologic and nonimmunologic factors. Because tacrolimus (Tac) has been ascribed a beneficial effect on some of these factors when compared to cyclosporine A (CyA), a randomized controlled trial was conducted to investigate whether conversion from CyA to Tac can ameliorate the progression of renal dysfunction in kidney transplant recipients (KTR) with CAN.

METHODS

Of the 46 patients with biopsy-proven CAN enrolled, 24 were converted from CyA to Tac, whereas 22 patients were maintained on CyA. Serum creatinine (SCrea), lipid profiles and an antihypertensive score (AHS) were determined after 3, 6 and 12 months. AHS is based on the total number and dosages of antihypertensive medications used. SCrea and AHS were additionally evaluated at 36 months.

RESULTS

SCrea was decreased in the Tac group (Tac(baseline): 297 +/- 67 micromol/L; Tac(6): 261+/- 70 micromol/L, P < 0.001; Tac(12): 254 +/- 55 micromol/L, P < 0.001; Tac(36): 255 +/- 78 micromol/L, P = 0.235), whereas a significant increase of SCrea was detected in the CyA group (CyA(baseline): 279 +/- 77 micromol/L, CyA(12): 333 +/- 98 micromol/L, P < 0.001; CyA(36): 317 +/- 89 micromol/L, P < 0.001). Compared to CyA therapy, SCrea in the Tac group declined after 12 and 36 months (P = 0.011 and 0.048, respectively) as well as AHS (Tac(12): 59 +/- 13, CyA(12): 83 +/- 14, P < 0.001; Tac(36): 60 +/- 12, CyA(36): 84 +/- 14, P < 0.001). LDL cholesterol was lower in the Tac group after 12 months (Tac(12): 2.5 +/- 0.5 mmol/L, CyA(12): 3.5 +/- 0.6 mmol/L, P < 0.001).

CONCLUSION

Conversion from CyA to Tac in KTR with CAN improves allograft function, lowers blood pressure, and reduces LDL cholesterol. This superior profile may translate into improved long-term graft survival.

Tacrolimus-associated hypomagnesemia in renal transplant recipients

BACKGROUND

Since hypomagnesemia occurs frequently in tacrolimus treated patients, we studied the correlation between renal magnesium wasting and tacrolimus blood levels in renal transplant patients.

METHODS

Serum magnesium, fractional excretion of magnesium (FEMg), and 24-hour urinary excretion of magnesium were measured in 41 transplant patients and 10 healthy volunteers for correlation with tacrolimus level.

RESULTS

Of tacrolimus-treated patients, 43% displayed hypomagnesemia. FEMg (7.42+/-3.59% versus 1.88+/-0.43%) and 24-hour urinary excretion (112.36+/-51.43 mg/dL versus 6.7+/-2.79 mg/dL) were significantly higher among tacrolimus-treated patients than controls. Magnesium replacement did not influence FEMg or 24-hour urinary magnesium excretion. Tacrolimus level was the best predictor of 24-hour urinary magnesium excretion and FEMg. Serum magnesium levels correlated inversely with tacrolimus concentrations and creatinine clearance.

CONCLUSION

Hypomagnesemia in renal transplant recipients results from renal magnesium wasting. Tacrolimus levels and renal function impact on the excess renal magnesium excretion. Studies of longer duration are warranted to assess the long-term effects of this early posttransplant hypomagnesemia.

Conversion from tacrolimus to cyclosporine in liver transplanted patients with diabetes mellitus

Adverse effects associated with calcineurin inhibitors may impact their clinical utility in some patients. This study characterizes the clinical outcomes of liver transplanted (LT) patients who experienced diabetes mellitus (DM) on tacrolimus-based regimen and were converted to cyclosporine-based therapy. Since January 2002, all patients with DM on a tacrolimus-based regimen were recruited and converted to cyclosporine-based therapy, after a 6-month minimal follow-up after LT. Clinical and laboratory data related to the clinical course of the patients were recorded. Twenty-five patients were included after a median delay of 54 months after LT [seven women and 18 men, 51 years (range 30-69)]. There were 11 patients with insulin-treated DM (ITDM), 14 patients with noninsulin-treated DM (NITDM), and the glycemic control was poor (HbA1c > 6.5%) in 13/25 patients (52%). After a median follow-up of 20 months after conversion, there were four patients with ITDM, 17 patients with NITDM, and four patients without DM, and the glycemic control was poor in 3/25 patients (12%). Four patients returned to tacrolimus because of arterial hypertension or digestive side-effects. In conclusion, our results suggest that conversion from tacrolimus to cyclosporine in stable LT patients with DM is well tolerated and beneficial on glycemic control.

Cardiovascular complications of immunosuppressive agents in renal transplant recipients

Fatal and nonfatal cardiovascular events are the most important cause of graft loss in patients with a functioning graft following transplantation. The available data indicate that transplant patients have a high prevalence of hypertension, hyperlipidaemia and new onset diabetes mellitus after transplantation. The aetiology and pathogenesis of post-transplant hypertension, hyperlipidaemia and diabetes are multifactorial. In addition, disease of the native kidney and recurrence of renal disease can contribute to the development of cardiovascular disease in transplant recipients. Most transplant patients are at risk of clinically important drug-drug interactions involving immunosuppressive agents. Adverse reactions and drug-drug interactions should not be neglected when selecting an agent for treatment of cardiovascular risk factors in transplant recipients.

2005 immunosuppressive strategies in kidney transplantation: which role for the calcineurin inhibitors?

The calcineurin inhibitors (CNIs) cyclosporine and tacrolimus have been the cornerstones of immunosuppressive strategies in clinical transplantation. Currently, regimens that are most widely used for induction and maintenance therapy include CNIs. However, many clinical trials aiming at reducing or eliminating CNIs have been performed in recent years. Here, we review and discuss current and future immunosuppressive strategies with a special emphasis on the role of CNIs, in the light of recent studies in the field of kidney transplantation. In the current era, CNIs still play an important role.

Early discontinuation of steroids is safe and effective in pediatric kidney transplant recipients

In pediatric kidney transplantation, steroid induced growth retardation and cushingoid features are of particular concern. In children, gradual steroid withdrawal late after kidney transplantation increases the risk of rejection. In this pilot study, we investigated the outcome of pediatric renal transplantation with an early steroid withdrawal protocol. This is a retrospective case-control study of pediatric renal transplants with age-matched historical control. Groups were comparable in terms of HLA matching, donor type and graft ischemia time. In the steroid withdrawal group (SWG, n = 13), induction therapy included mycophenolate mofetil (MMF) and a 5-day course of steroids with Thymoglobulin in 11 and basiliximab in two other patients. In the steroid group (SG, n = 13), in addition to steroids, four patients were given basiliximab, eight were given Thymoglobulin, and one OKT3. Maintenance therapy included tacrolimus (SWG n = 11, SG n = 3) or cyclosporine (SWG n = 2, SG n = 10). Azathioprine was given to all the patients in the SG, except the last two patients of this series who were prescribed MMF. MMF was given to all in the SWG. Patient and graft survival rates were 100% in both groups. In the SWG, no acute rejection episode was detected. In the steroid group, three patients (25%) presented with an acute rejection episode. All but one patient in either group showed immediate graft function. Patients in the steroid-withdrawal group exhibited a significantly higher creatinine clearance at 6 and 12 months post-transplant (95.8 +/- 23.3 vs. 71.3 +/- 21.9, p = 0.03; and 91.3 +/- 21.6 vs. 69.6 +/- 28.6, p = 0.04). In the SWG delta BMI was significantly lower and delta height Z score was significantly higher, and we observed significantly less hyperlipidemia, body disfigurement, and need for anti-hypertensive medication. Early steroid withdrawal in pediatric renal transplant recipients is efficacious and safe and does not increase risk of rejection, preserving optimal growth and renal function, and reducing cardiovascular risk factors.

Open prospective multicenter study of conversion to tacrolimus therapy in renal transplant patients experiencing ciclosporin-related side-effects

The hyperlipidemic and hypertensive effects of ciclosporin constitute a cardiovascular risk. Cosmetic side-effects are known to reduce patients' quality of life. This was a 6-month, open, prospective, multicentre study in 296 adult kidney transplant patients to evaluate the conversion from ciclosporin to a tacrolimus-based regimen. Primary indications for conversion were hyperlipidemia (n =77), hypertension (n = 72), hypertrichosis (n = 32) and gingival hyperplasia (n = 115). At month 6, hyperlipidemia and hypertension were at least moderately improved in 59.1% and 63.5% of patients, and strongly or completely resolved in 29% and 25%. Gingival hyperplasia and hypertrichosis were strongly or completely resolved in 73% and 72% of patients. Mean total cholesterol was reduced from 255 to 218 mg/dl. Mean systolic blood pressure (SBP) was reduced from 152.9 to 137.5 mmHg and mean diastolic blood pressure (DBP) from 90.7 to 85.8 mmHg. Ciclosporin-related side-effects resolved or improved after conversion to tacrolimus.

Tacrolimus and Posttransplant Diabetes Mellitus in Renal Transplantation

The most prominent side effect of tacrolimus is the induction of posttransplant diabetes mellitus (PTDM). In this review, the authors discuss the incidence, mechanism, prevention, and treatment of tacrolimus-induced PTDM in renal patients.

Conversion From Cyclosporine to Tacrolimus Results in Improved Creatinine But Does Not Alter Lipid Profile

INTRODUCTION

While cyclosporine and tacrolimus use results in similar renal graft survival, the side effect profiles of the drugs are substantially different. We examined the electrolyte and lipid alterations that occurred in our patient population following conversion from cyclosporine to tacrolimus.

METHODS

Data for electrolytes, lipid profile, and immunosuppression were analyzed from 98 patients with kidney or kidney-pancreas transplants who were converted from cyclosporine to tacrolimus between October 1994 and June 2001. Results, expressed as mean +/- SEM, were compared to baseline values using the Wilcoxon signed-rank test (P < .05 considered significant).

RESULTS

Among these patients, there were 56 men, 42 women, 75 primary transplants, 15 repeat transplants, and 26 multiorgan transplants. The mean time to tacrolimus conversion was 769 +/- 122 days. Creatinine, BUN, and glucose improved after conversion to tacrolimus. Surprisingly, cholesterol, low-density lipoproteins, and high-density lipoproteins levels were not significantly altered, although triglyceride levels demonstrated a significant difference at 1 year.

CONCLUSION

Significant improvements in creatinine and BUN were observed following conversion from cyclosporine to tacrolimus. While hypomagnesemia was also seen, there was surprisingly little alteration in lipid profile.