Cardiovascular risk factors and estimated risk for CAD in a randomized trial comparing calcineurin inhibitors in renal transplantation

Association of Serum Osteoprotegerin With Vascular Calcification, and Cardiovascular and Graft Outcomes in Kidney Transplant Patients: Results From the KNOW-KT

BACKGROUND

Vascular calcification and stiffness contribute to increased cardiovascular morbidity in patients with chronic kidney disease. This study investigated associations between serum osteoprotegerin (OPG) levels and vascular calcification or stiffness to assess cardiovascular and graft outcomes in kidney transplant patients.

METHODS

The KoreaN cohort study for Outcome in patients With Kidney Transplantation was a prospective multicenter cohort study. Serum OPG levels were measured at baseline and 3 y after transplantation in 1018 patients. Patients were classified into high and low OPG groups according to median serum OPG levels. The median follow-up duration was 93.5 mo.

RESULTS

The mean age was 45.8 ± 11.7 y and 62.9% were men. Patients with high OPG had significantly higher coronary artery calcium scores, abdominal aortic calcification scores, and brachial-ankle pulse wave velocities than those with lower OPG; these parameters remained significant for 5 y after transplantation. The 3-y OPG levels were lower than baseline values ( P  < 0.001) and were positively correlated ( r  = 0.42, P  < 0.001). Multivariate Cox regression analysis showed that high OPG levels were significantly associated with posttransplant cardiovascular events ( P  = 0.008) and death-censored graft loss ( P  = 0.004). Similar findings regarding posttransplant cardiovascular events ( P  = 0.012) and death-censored graft loss ( P  = 0.037) were noted in patients with high OPG at the 3-y follow-up. Mediation analyses revealed that coronary artery calcium scores, abdominal aortic calcification scores, and brachial-ankle pulse wave velocities could act as mediators between serum OPG levels and posttransplant cardiovascular events.

CONCLUSIONS

Serum OPG concentration is associated with vascular calcification and stiffness and could be a significant risk factor for cardiovascular outcomes and graft loss in patients undergoing kidney transplantation.

Classification models for assessing coronary artery disease instances using clinical and biometric data: an explainable man-in-the-loop approach

The main goal driving this work is to develop computer-aided classification models relying on clinical data to identify coronary artery disease (CAD) instances with high accuracy while incorporating the expert's opinion as input, making it a "man-in-the-loop" approach. CAD is traditionally diagnosed in a definite manner by Invasive Coronary Angiography (ICA). A dataset was created using biometric and clinical data from 571 patients (21 total features, 43% ICA-confirmed CAD instances) along with the expert's diagnostic yield. Five machine learning classification algorithms were applied to the dataset. For the selection of the best feature set for each algorithm, three different parameter selection algorithms were used. Each ML model's performance was evaluated using common metrics, and the best resulting feature set for each is presented. A stratified ten-fold validation was used for the performance evaluation. This procedure was run both using the assessments of experts/doctors as input and without them. The significance of this paper lies in its innovative approach of incorporating the expert's opinion as input in the classification process, making it a "man-in-the-loop" approach. This approach not only increases the accuracy of the models but also provides an added layer of explainability and transparency, allowing for greater trust and confidence in the results. Maximum achievable accuracy, sensitivity, and specificity are 83.02%, 90.32%, and 85.49% when using the expert's diagnosis as input, compared to 78.29%, 76.61%, and 86.07% without the expert's diagnosis. The results of this study demonstrate the potential for this approach to improve the diagnosis of CAD and highlight the importance of considering the role of human expertise in the development of computer-aided classification models.

Early calcineurin-inhibitor to belatacept conversion in steroid-free kidney transplant recipients

Background

Belatacept (Bela) was developed to reduce nephrotoxicity and cardiovascular risk that are associated with the chronic use of Calcineurin inhibitors (CNIs) in kidney transplant recipients. The use of Bela with early steroid withdrawal (ESW) and simultaneous CNI avoidance has not been formally evaluated.

Methods

At 3 months post-transplant, stable kidney transplant recipients with ESW on Tacrolimus (Tac) + mycophenolate (MPA) were randomized 1:1:1 to: 1) Bela+MPA, 2) Bela+low-dose Tac (trough goal <5 ng/mL), or 3) continue Tac+MPA. All patients underwent surveillance graft biopsies at enrollment and then at 12, and 24 months post-transplant. Twenty-seven recipients were included; 9 underwent conversion to Bela+MPA, 8 to Bela+low-dose Tac and 10 continued Tac+MPA. Serial blood samples were collected for immune phenotyping and gene expression analyses.

Results

The Bela+MPA arm was closed early due to high rate of biopsy proven acute rejection (BPAR). The incidence of BPAR was 4/9 in Bela+MPA, 0/8 in Bela+low dose Tac and 2/10 in Tac+MPA, P= 0.087. The Bela+low-dose Tac regimen was associated with +8.8 mL/min/1.73 m² increase in eGFR compared to -0.38 mL/min/1.73 m² in Tac+MPA, P= 0.243. One graft loss occurred in the Bela+MPA group. Immunophenotyping of peripheral blood monocyte count (PBMC) showed that CD28⁺CD4⁺ and CD28⁺CD8⁺ T cells were higher in Bela+MPA patients with acute rejection compared to patients without rejection, although the difference did not reach statistical significance.

Conclusions

Our data indicate that, in steroid free regimens, low-dose Tac maintenance is needed to prevent rejection when patients are converted to Bela, at least when the maneuver is done early after transplant.

Trends in the effects of pre-transplant diabetes on mortality and cardiovascular events after kidney transplantation

AIMS/INTRODUCTION

It is not clear whether survival in kidney transplant recipients with pre-transplant diabetes has improved over the past decades. We compared the rates of mortality and major adverse cardiovascular events (MACE) after renal transplantation in patients with and without pre-transplant diabetes. Furthermore, we investigated whether transplant era and recipient age affected the association between diabetes status and adverse events.

MATERIALS AND METHODS

This retrospective cohort study included 691 patients who underwent renal transplantation between 1994 and 2016 at a single tertiary center. We compared the incidences of post-transplant mortality and four-point MACE in patients with and without pre-transplant diabetes using Kaplan-Meier analysis and the Cox proportional hazard model, and assessed the interactions between diabetes status and transplant era and recipient age.

RESULTS

Of 691 kidney recipients, 143 (20.7%) had pre-transplant diabetes. The mean follow-up duration was 94.5 months. Kaplan-Meier analysis showed that patients with pre-transplant diabetes had higher incidences of post-transplant mortality and four-point MACE compared with those without pre-transplant diabetes (log-rank test, P < 0.001 for both). After adjusting for potential confounding factors, pre-transplant diabetes was associated with an increased risk of post-transplant mortality and four-point MACE (hazard ratio 1.90, 95% confidence interval 1.05-3.44, P = 0.034; and hazard ratio 1.75; 95% confidence interval 1.02-3.00, P = 0.043, respectively). The associations between pre-transplant diabetes status and all-cause mortality and four-point MACE were not affected by transplant era or recipient age.

CONCLUSIONS

Pre-transplant diabetes remains a significant risk factor for mortality and four-point MACE in kidney transplant recipients.

Early postoperative acute myocardial infarction in kidney transplant recipients: A nested case-control study

INTRODUCTION

The epidemiology of early acute myocardial infarctions after kidney transplantation has not been well characterized. This study sought to examine the incidence, risk factors, and clinical outcomes of early acute myocardial infarctions or EAMI in kidney transplant recipients.

METHODS

A total of 1976 patients who underwent kidney transplantation at our center from Jan 1, 2000, to Sept 30, 2016, were included. A nested case-control design was used to study EAMI risk factors using a conditional logistic regression model. A Cox proportional hazards model was used to assess the association of EAMI with death-censored graft failure, death with graft function, and total graft failure.

RESULTS

Seventy four patients had an EAMI within 3 months post-transplant. Based on univariable analyses, risk factors for EAMI included age and recipient history of diabetes mellitus or coronary artery disease. After adjustment, recipient history of coronary artery disease was the only independent predictor for EAMI (OR 3.76, p < .001). Patients who experienced EAMI were more likely to experience death-censored graft failure, death with graft function, and total graft failure.

CONCLUSION

While the incidence of EAMI in kidney transplant recipients is relatively low, these data show that EAMI has profound long-term effects on morbidity and mortality.

Outcomes Following Percutaneous Coronary Intervention in Renal Transplant Recipients: A Binational Collaborative Analysis

OBJECTIVE

To investigate the clinical and procedural characteristics in patients with a history of renal transplant (RT) and compare the outcomes with patients without RT in 2 national cohorts of patients undergoing percutaneous coronary intervention (PCI).

PATIENTS AND METHODS

Data from the National Inpatient Sample (NIS) and British Cardiovascular Intervention Society (BCIS) were used to compare the clinical and procedural characteristics and outcomes of patients undergoing PCI who had RT with those who did not have RT. The primary outcome of interest was in-hospital mortality.

RESULTS

Of the PCI procedures performed in 2004-2014 (NIS) and 2007-2014 (BCIS), 12,529 of 6,601,526 (0.2%) and 1521 of 512,356 (0.3%), respectively, were undertaken in patients with a history of RT. Patients with RT were younger and had a higher prevalence of congestive cardiac failure, hypertension, and diabetes but similar use of drug-eluting stents, intracoronary imaging, and pressure wire studies compared with patients who did not have RT. In the adjusted analysis, patients with RT had increased odds of in-hospital mortality (NIS: odds ratio [OR], 1.90; 95% CI, 1.41-2.57; BCIS: OR, 1.60; 95% CI, 1.05-2.46) compared with patients who did not have RT but no difference in vascular or bleeding events. Meta-analysis of the 2 data sets suggested an increase in in-hospital mortality (OR, 1.79; 95% CI, 1.40-2.29) but no difference in vascular (OR, 1.24; 95% CI, 0.77-2.00) or bleeding (OR, 1.21; 95% CI, 0.86-1.68) events.

CONCLUSION

This large collaborative analysis of 2 national databases revealed that patients with RT undergoing PCI are younger, have more comorbidities, and have increased mortality risk compared with the general population undergoing PCI.

Outcomes of Renal Transplant Recipients after Percutaneous Coronary Intervention

Renal transplantation (RT) can improve life expectancy in hemodialysis (HD) patients. However, little is known about the outcomes of renal transplant recipients after percutaneous coronary intervention (PCI). This study aimed to elucidate the effect of RT on clinical outcomes after PCI. Renal transplant recipients who underwent PCI from 2002 to 2017 were enrolled. To evaluate the effectiveness of RT, we retrospectively reviewed HD patients who underwent PCI. Propensity-score matching was performed using logistic regression to control for differences in baseline characteristics. The primary outcome was the incidence of major adverse cardiac events. After propensity matching, patients were classified into the RT (n = 50) group and HD (n = 50) group. Kaplan-Meier analysis revealed that the incidence of major adverse cardiac events was significantly lower in the RT group than in the HD group (p < 0.0001). Moreover, RT was associated with a lower risk for all-cause death (odds ratio 0.04; 95% confidence interval 0.002 to 0.03; p = 0.0054) and target vessel revascularization (OR 0.27; 95% CI 0.07 to 0.79; p = 0.015). RT may improve clinical outcomes after PCI, and it is encouraged for HD patients to increase life expectancy and reduce the occurrence of adverse events after PCI. Further research would be warranted to support this finding.

Pros and Cons of Aspirin Prophylaxis for Prevention of Cardiovascular Events in Kidney Transplantation and Review of Evidence

Kidney transplant recipients have traditional and nontraditional risk factors which can lead to coronary artery disease and sudden death with a functional graft loss. Aspirin has been used traditionally for prevention of cardiovascular and cerebrovascular accidents. It has beneficial effects in secondary prevention of cardiovascular events in general population. Its use for primary prophylaxis is still disputed. Bleeding and theoretical risk of nephrotoxicity are the major concerns about its use. The data on aspirin in kidney transplant population is sparse. This review will focus on various pros and cons of aspirin use for prevention of cardiovascular events in kidney transplant recipients and a way forward.

Pulse Pressure and Outcome in Kidney Transplantation: Results From the Collaborative Transplant Study

BACKGROUND

Systolic blood pressure (SBP) and diastolic blood pressure (DBP) are important predictors of graft and patient survival in renal transplantation. Pulse pressure (PP), the difference between systolic and diastolic pressure, has been associated with cardiovascular and renal morbidity in nontransplant epidemiological studies and clinical trials.

METHODS

In this large retrospective analysis of prospectively collected data, transplant recipients from 1995 to 2015 were examined for patient and death-censored graft survival.

RESULTS

In 43 006 recipients, a higher 1-year PP was significantly associated with inferior 10-year patient and death-censored graft survival. In patients 60 years or older, SBP but not DBP was associated with 10-year survival, an effect that was pronounced in patients with a normal SBP of <140 mm Hg and an increased PP of 60 mm Hg or greater, highlighting the superior impact of PP on survival in elderly recipients. In recipients 60 years or older, higher PP was associated with increased mortality due to circulatory system diseases but not to infection or cancer. The combination of PP 60 mm Hg or greater and high SBP of 140 mm Hg or greater showed the strongest association with death-censored graft survival across all age groups.

CONCLUSIONS

We found convincing evidence that PP 1-year posttransplant is predictive of patient survival, especially in elderly recipients with normal SBP. Combined analysis of SBP and PP showed that high PP confers additional predictive information for patient survival beyond that derived from analysis of SBP alone. With regard to prediction of death-censored graft survival, the combination of high SBP and high PP showed the best correlation across all age groups.

Factor VIIa administration in orthotopic heart transplant recipients and its impact on thromboembolic events and post-transplant outcomes

Recombinant, activated factor VIIa (rFVIIa) is used during cardiac surgeries to mitigate refractory coagulopathic bleeding. The purpose of this study was to examine whether rFVIIa use in orthotopic heart transplant (OHT) recipients was associated with a higher incidence of thromboembolic (TE) events compared to patients who did not. A single-center, retrospective, cohort study was performed on OHT recipients who received rFVIIa for refractory coagulopathic bleeding from January 2013 to December 2015. Patients were evaluated for up to 6 months after transplantation and assessed for TE events, rejection, readmissions, graft survival, and patient survival. Categorical variables were analyzed using the Chi square test while student's t or ANOVA testing was utilized for continuous variables. Of the 62 patients who met inclusion criteria, 27 patients received rFVIIa, and 35 patients were selected for the control group. The overall incidence of TE events was not significantly different between patients who received rFVIIa compared to patients in the control group (14.8% vs 11.4%) (p = 0.69). Within 14 days, 14.81% of rFVIIa patients suffered a TE event compared to 5.7% of the control group (p = 0.23). Rejection, readmissions, graft survival, and patient survival were not significantly different at any time points. Use of rFVIIa in heart transplantation showed no difference in the overall rate of TE events, however, there was a nonsignificant trend toward higher risk of early TE development in the rFVIIa group compared to the control group.

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.

Ten-year outcomes in a randomized phase II study of kidney transplant recipients administered belatacept 4-weekly or 8-weekly

In the phase II IM103-100 study, kidney transplant recipients were first randomized to belatacept more-intensive-based (n = 74), belatacept less-intensive-based (n = 71), or cyclosporine-based (n = 73) immunosuppression. At 3-6 months posttransplant, belatacept-treated patients were re-randomized to receive belatacept every 4 weeks (4-weekly, n = 62) or every 8 weeks (8-weekly, n = 60). Patients initially randomized to cyclosporine continued to receive cyclosporine-based immunosuppression. Cumulative rates of biopsy-proven acute rejection (BPAR) from first randomization to year 10 were 22.8%, 37.0%, and 25.8% for belatacept more-intensive, belatacept less-intensive, and cyclosporine, respectively (belatacept more-intensive vs cyclosporine: hazard ratio [HR] = 0.95; 95% confidence interval [CI] 0.47-1.92; P = .89; belatacept less-intensive vs cyclosporine: HR = 1.61; 95% CI 0.85-3.05; P = .15). Cumulative BPAR rates from second randomization to year 10 for belatacept 4-weekly, belatacept 8-weekly, and cyclosporine were 11.1%, 21.9%, and 13.9%, respectively (belatacept 4-weekly vs cyclosporine: HR = 1.06, 95% CI 0.35-3.17, P = .92; belatacept 8-weekly vs cyclosporine: HR = 2.00, 95% CI 0.75-5.35, P = .17). Renal function trends were estimated using a repeated-measures model. Estimated mean GFR values at year 10 for belatacept 4-weekly, belatacept 8-weekly, and cyclosporine were 67.0, 68.7, and 42.7 mL/min per 1.73 m² , respectively (P<.001 for overall treatment effect). Although not statistically significant, rates of BPAR were 2-fold higher in patients administered belatacept every 8 weeks vs every 4 weeks.

Cell Therapy in Kidney Transplantation: Focus on Regulatory T Cells

Renal transplantation is the renal replacement modality of choice for suitable candidates with advanced CKD or ESRD. Prevention of rejection, however, requires treatment with nonspecific pharmacologic immunosuppressants that carry both systemic and nephrologic toxicities. Use of a patient's own suppressive regulatory T cells (Tregs) is an attractive biologic approach to reduce this burden. Here, we review the immunologic underpinnings of Treg therapy and technical challenges to developing successful cell therapy. These issues include the selection of appropriate Treg subsets, ex vivo Treg expansion approaches, how many Tregs to administer and when, and how to care for patients after Treg administration.

Efficacy and safety of tacrolimus compared with ciclosporin-A in renal transplantation: 7-year observational results

The European Tacrolimus versus Ciclosporin-A Microemulsion (CsA-ME) Renal Transplantation Study demonstrated that tacrolimus decreased acute rejection rates at 6 months. Primary endpoints of this investigator-initiated, observational 7-year follow-up study were acute rejection rates, patient and graft survival rates, and a composite endpoint (BPAR, graft loss, and patient death). We analyzed data from the original intent-to-treat population (n = 557; 286 tacrolimus, 271 CsA-ME). A total of 237 tacrolimus and 208 CsA-ME patients provided data. At 7 years, Kaplan-Meier estimated rates of patients free from BPAR were 77.1% in the tacrolimus arm and 59.9% in the CsA-ME arm, graft survival rates amounted to 82.6% and 80.6%, and patient survival rates to 89.9% and 88.1%. Estimated combined endpoint-free survival rates were 60.2% in the tacrolimus arm and 47.0% in the CsA-ME arm (P = <0.0001). A higher number of patients from the CsA-ME arm crossed over to tacrolimus during 7 year follow-up: 19.7% vs. 7.9% (P = <0.002). More patients in the tacrolimus group stopped steroids and received immunosuppressive monotherapy. Significantly, more CsA-ME patients received lipid-lowering medication and experienced cosmetic and cardiovascular adverse events. Tacrolimus-treated renal transplant recipients had significantly higher combined endpoint-free survival rates mainly driven by lower acute rejection rates despite less immunosuppressive medication at 7 years.

Association between circulating thrombopoietin levels and cardiovascular risk prediction scores in renal transplant recipients

BACKGROUND/AIMS

The 7-year Major Adverse Cardiovascular Events Calculator (CRCRTR-MACE) predicts cardiovascular events (CVE) in renal transplant recipients (RTR), and thrombopoietin (TPO) is a humoral inflammatory factor implicated in cardiovascular disease (CVD). The aim of the study was to determine if circulating TPO levels in stable RTR are positively associated with variable(s) in the CRCRTR-MACE score.

METHODS

CRCRTR-MACE scores were calculated in 95 stable RTR. TPO levels were measured by multiplexed fluorescent bead-based immunoassay in all patients and 48 controls. Multivariate analysis (MVA) was performed between TPO and CV risk variables and patient demographics. Stepwise regression with backward elimination of insignificant variables estimated the impact of risk variables on TPO levels. Significance was defined at p < 0.05. Normalized data were presented as mean ± SD and non-normalized data as median (maximum to minimum).

RESULTS

The risk of a CVE within 7 years as predicted by the median was 9.97% (range 1.93-84.2). The percentage of patients who were above 20% risk for a CVE was 28.4%. Control TPO level of 170.41 (4.4-995.9) pg/ml was significantly lower than that of 237.90 (32.77-1,386.79) pg/ml in RTR (p = 0.010). TPO level correlated significantly with the total CRCRTR-MACE score (R = 0.310, p = 0.004), smoking (p = 0.009) and eGFR (R = -0.275, p = 0.012) but not with age, diabetes, LDL level or history of CVE. Only the total CRCRTR-MACE score (p = 0.013) and smoking (p = 0.009) remained significant in the MVA. Stepwise regression estimated that smoking increased TPO levels by 206.28 pg/ml and each 10% increase in CRCRTR-MACE score increased TPO levels by an additional 44.4 pg/ml.

CONCLUSION

TPO levels are increased in RTR with high CRCRTR-MACE, particularly in smokers with diminished eGFR. Circulating TPO may serve as a biomarker and treatment target for CVD in RTR.

Validity of cardiovascular risk prediction models in kidney transplant recipients

Background. Predicting cardiovascular risk is of great interest in renal transplant recipients since cardiovascular disease is the leading cause of mortality. Objective. To conduct a systematic review to assess the validity of cardiovascular risk prediction models in this population. Methods. Five databases were searched (MEDLINE, EMBASE, SCOPUS, CINAHL, and Web of Science) and cohort studies with at least one year of follow-up were included. Variables that described population characteristics, study design, and prognostic performance were extracted. The Quality in Prognostic Studies (QUIPS) tool was used to evaluate bias. Results. Seven studies met the criteria for inclusion, of which, five investigated the Framingham risk score and three used a transplant-specific model. Sample sizes ranged from 344 to 23,575, and three studies lacked sufficient event rates to confidently reach conclusion. Four studies reported discrimination (as measured by c-statistic), which ranged from 0.701 to 0.75, while only one risk model was both internally and externally validated. Conclusion. The Framingham has underestimated cardiovascular events in renal transplant recipients, but these studies have not been robust. A risk prediction model has been externally validated at least on one occasion, but comprehensive validation in multiple cohorts and impact analysis are recommended before widespread clinical application is advocated.

Multivessel coronary revascularization and outcomes in kidney transplant recipients

Coronary artery disease is a major cause of morbidity and mortality in the kidney transplant population. We compared the long-term outcomes of coronary artery bypass graft (CABG) surgery with percutaneous coronary intervention (PCI) for multivessel coronary disease in a contemporary cohort of US kidney transplant recipients. From the U.S. Renal Data System, we identified all adult kidney transplant patients with ≥6 months of Medicare A+B undergoing first recorded multivessel coronary revascularization from 1997 to 2009. The associations of CABG versus PCI with death and the composite of death or myocardial infarction (MI) were compared using proportional hazards regression. Of the 2272 patients included in the study, 1594 underwent CABG and 678 underwent PCI. The estimated 5-year survival rate was 55% [95% confidence interval (CI) 53% to 57%] following coronary revascularization, with no significant association between revascularization type and death [adjusted hazard ratio (aHR) = 1.08; CI 0.94-1.23] or the composite of death or MI (aHR = 1.07; CI 0.96-1.18). Separate propensity score-matched analyses yielded similar results. In this analysis of kidney transplant recipients undergoing multivessel coronary revascularization, we found no difference between CABG and PCI in terms of survival or the composite of death and MI.

Effect of conversion from ciclosporin to tacrolimus on endothelial progenitor cells in stable long-term kidney transplant recipients

BACKGROUND

Endothelial progenitor cell (EPC) counts are proposed surrogate markers for vascular function and cardiovascular risk. The effect of tacrolimus (TAC) on EPC is unknown.

METHODS

In this randomized controlled trial, we assigned 148 stable long-term kidney transplant recipients (KTR) to maintaining ciclosporin (CSA) or to commencing TAC-based immunosuppression at a 2:1 ratio. EPC counts (CD34/KDR) after 24 months were defined as primary endpoint.

RESULTS

The intent-to-treat analysis included 141 KTR (estimated glomerular filtration rate, 46.7 [40.1-61.8] mL/min per 1.73 m). Median (interquartile range [IQR]) EPC counts at baseline and month 24 were 6 (2-9) and 3 (1-9) cells and 4 (2-8) and 2 (0-5) cells per 5×10 mononuclear cells in CSA and TAC, respectively. Median (IQR) circulating angiogenic cells at baseline and month 24 were 28 (10.7-57) and 44.33 (14.6-59.8) cells and 22 (10.8-41) and 21 (9.7-49.5) cells per high-power field in CSA and TAC, respectively. Median (IQR) endothelial cell colony-forming units count per well at baseline and month 24 were 10.5 (3.3-34.3) and 4.38 (1.7-26.5) in CSA and significantly declined from 9.31 (1.8-29.3) to 4.13 (1.1-9.5) in TAC (P=0.003). There were no cardiovascular events in either group.

CONCLUSION

Although late conversion from CSA to TAC appears safe in KTR, conversion to TAC has no favorable effect on EPC. Low EPC levels are associated with a higher risk of subsequent cardiovascular events and are therefore of prognostic value. Their trend to decline over time deserves further examination.

Randomized trial of everolimus-facilitated calcineurin inhibitor minimization over 24 months in renal transplantation

BACKGROUND

Strategies allowing calcineurin inhibitor minimization while maintaining efficacy may improve renal transplant outcomes.

METHODS

A2309 was a 24-month, phase IIIb, open-label trial of 833 de novo renal transplant recipients randomized to everolimus, targeting trough concentrations of 3-8 or 6-12 ng/mL plus reduced-exposure cyclosporine A (CsA) or to mycophenolic acid (MPA) 1.44 g per day plus standard-exposure CsA. All patients received basiliximab ± corticosteroids. The incidence of the primary composite efficacy endpoint and its components (treated biopsy-proven acute rejection, graft loss, death, or loss to follow-up), renal function (serum creatinine and estimated glomerular filtration rate), and adverse events (AEs) were compared at 24 months; as per the protocol, these analyses were not noninferiority.

RESULTS

Composite efficacy failure rates (95% confidence interval for difference vs. MPA) were 32.9% (-2.2%, 13.0%), 26.9% (-7.9%, 6.8%), and 27.4% at month 24 in the everolimus 3-8 and 6-12 ng/mL and MPA groups, respectively. Mean estimated glomerular filtration rate (Modification of Diet in Renal Disease) at month 24 was 52.2 (-2.1, 5.5 mL/min/1.73 m(2)), 49.4 (-4.8, 2.7 mL/min/1.73 m(2)), and 50.5 mL/min/1.73 m(2), respectively. AEs were generally mild to moderate in severity and comparable between the groups. AEs leading to discontinuation were reported in 28.5% (P = 0.03 vs. MPA), 30.6% (P = 0.007 vs. MPA), and 20.5% of patients receiving everolimus 3-8 and 6-12 ng/mL and MPA, respectively.

CONCLUSIONS

Everolimus trough concentrations targeted to 3-8 ng/mL, along with a greater than 60% reduction in CsA exposure, was associated with comparable efficacy and renal function versus MPA plus standard-exposure CsA over the 2-year period. A significantly higher incidence of AEs led to discontinuation in the everolimus groups compared with the MPA group.

The external validation of the cardiovascular risk equation for renal transplant recipients: applications to BENEFIT and BENEFIT-EXT trials

BACKGROUND

Renal transplant recipients (RTRs) have increased cardiovascular disease risk. Recently, major adverse cardiac event (MACE) and mortality risk calculators for prevalent RTRs were developed. We aimed to externally validate these risk equations in an international transplant database and subsequently demonstrate application to 2 clinical trials: Belatacept Evaluation of Nephroprotection and Efficacy as First-line Immunosuppression Trial (BENEFIT) and Belatacept Evaluation of Nephroprotection and Efficacy as First-line Immunosuppression Trial-EXTended criteria donors (BENEFIT-EXT).

METHODS

The 7-year risk calculators were developed using data from the ALERT trial and validated for discrimination and calibration in the Patient Outcomes in Renal Transplantation (PORT) study cohort. The outlier laboratory readings were trimmed to the 99th percentile observed in the PORT database. Diabetes mellitus, LDL-cholesterol, and serum creatinine values 3 years posttransplantation were used when applying the calculators to BENEFIT and BENEFIT-EXT trial treatment arms.

RESULTS

MACE could be predicted using a 7-variable model. The area under the ROC curve was 0.738 in ALERT and 0.740 in PORT, indicating preserved discrimination. In PORT, the calibration of the model indicated significant underestimation of risk in decile 5 and 9. Total mortality could be predicted using a 6-variable model. The area under the ROC curve was 0.734 in ALERT and 0.721 in PORT, indicating preserved discrimination. In PORT, the calibration of the model indicated significant underestimation of risk in decile 7 and significant overestimation in the highest risk decile. In BENEFIT and BENEFIT-EXT trial, the calculator estimated that belatacept use may result in reduction in MACE (>20%) and mortality (∼18%-30%).

CONCLUSION

The MACE and mortality risk calculators for prevalent RTRs have been externally validated and found suitable for generic risk stratification.

A cardiovascular risk calculator for renal transplant recipients

BACKGROUND

Renal transplant recipients (RTRs) have increased cardiovascular disease (CVD) risk. Standard CVD risk calculators are poorly predictive in RTRs; we therefore aimed to develop and validate an equation for CVD risk prediction in this population.

METHODS

We used data from the Assessment of Lescol in Renal Transplantation trial, which are randomly divided into an assessment sample and a test sample (67% and 33%, respectively, of the total population). For variable selection in the assessment sample, backward stepwise Cox regression was used. Using the regression coefficients and centralized prognostic index, risk was calculated for individual patients. The equation was then validated for calibration and discrimination using the test sample.

RESULTS

Major adverse cardiac events could be predicted using a seven-variable model including age, previous coronary heart disease, diabetes, low-density lipoprotein, creatinine, number of transplants, and smoking. The calibration of the model was good in the test sample with a Hosmer-Lemeshow chi-square value of 11.47 and a P value of 0.245. The areas under the receiver operating characteristic curve were 0.738 in the assessment sample and 0.740 in the test sample. Total mortality could be predicted using a six-variable model including age, coronary heart disease, diabetes, creatinine, total time on renal replacement therapy, and smoking. The calibration of the model was acceptable in the test sample with a Hosmer-Lemeshow chi-square value of 13.08 and a P value of 0.109. The areas under the receiver operating characteristic curve were 0.734 in the assessment sample and 0.720 in the test sample.

CONCLUSIONS

Using the Assessment of Lescol in Renal Transplantation trial population, a formula for 7-year CVD and mortality risk calculation for prevalent RTRs has been developed.

The use of a DNA biobank linked to electronic medical records to characterize pharmacogenomic predictors of tacrolimus dose requirement in kidney transplant recipients

OBJECTIVE

Tacrolimus, an immunosuppressive drug widely prescribed in kidney transplantation, requires therapeutic drug monitoring due to its marked interindividual pharmacokinetic variability and narrow therapeutic index. Previous studies have established that CYP3A5 rs776746 is associated with tacrolimus clearance, blood concentration, and dose requirement. The importance of other drug absorption, distribution, metabolism, and elimination (ADME) gene variants has not been well characterized.

METHODS

We used novel DNA biobank and electronic medical record resources to identify ADME variants associated with tacrolimus dose requirement. Broad ADME genotyping was performed on 446 kidney transplant recipients, who had been dosed to a steady state with tacrolimus. The cohort was obtained from Vanderbilt's DNA biobank, BioVU, which contains linked deidentified electronic medical record data. Genotyping included Affymetrix drug-metabolizing enzymes and transporters Plus (1936 polymorphisms), custom Sequenom Massarray iPLEX Gold assay (95 polymorphisms), and ancestry-informative markers. The primary outcome was tacrolimus dose requirement defined as blood concentration to dose ratio.

RESULTS

In analyses, which adjusted for race and other clinical factors, we replicated the association of tacrolimus blood concentration to dose ratio with CYP3A5 rs776746 (P=7.15×10), and identified associations with nine variants in linkage disequilibrium with rs776746, including eight CYP3A4 variants. No NR1I2 variants were significantly associated. Age, weight, and hemoglobin were also significantly associated with the outcome. In final models, rs776746 explained 39% of variability in dose requirement and 46% was explained by the model containing clinical covariates.

CONCLUSION

This study highlights the utility of DNA biobanks and electronic medical records for tacrolimus pharmacogenomic research.

[Evaluation of patients' readiness for surgery when called from the waiting list for kidney transplantation: experience of the Budapest Centre]

The aim of this study was to assess the impact of the establishment of waiting list committee on recipient evaluation for kidney transplantation. Studies on this issue have not been previously reported.

METHODS

Data of 714 patients were collected between September 1, 2007 and April 20, 2010. Of the 714 patients 354 were transplanted. Data from the first 16 months period were compared to those obtained during the second 16 months period.

RESULTS

During the first period 171 patients (47.9%) were unfit for transplantation [129 patients (36.1%) were refused after telephone information and 42 patients (11.8%) after clinical investigation]. During the second period 141 (39.5%) patients were found to be unsuitable [80 patients (22.4%) after telephone information and 61 patients (17.1)] after clinical examination. During the two periods of the study 44% of patients were unfit for transplantation. A considerable number of patients were refused because of cardiologic reasons. The percent of fit patients was 52.1% in the first period and 60.5% in the second period. In addition, the percent of unfit patients who were unsuitable for kidney transplantation after telephone information decreased from 36.1% to 22.4%, while the percent of unfit patients after clinical evaluation increased from 11.% to 17.1%.

CONCLUSIONS

Authors conclude that waiting list committee made an effective work.

Presence of cardiovascular disease in patients on a waiting list for renal transplantation and in patients after kidney transplantation in a single center

BACKGROUND

Cardiovascular risk in hemodialysis patients is enhanced, resulting in a higher mortality rate compared with the general population, yet the average wait time for renal transplantation in Germany is 5-7 years. The age of wait-listed patients has risen progressively. The aim of this study was to evaluate the prevalence of cardiovascular disease in patients on the waiting list in our center before and after renal transplantation as well as the extent to which invasive treatment was required in these patients.

METHODS

The study investigated 2 groups: 350 patients on the renal transplantation waiting list at our center in 2008 and 324 patients who underwent renal transplantation at the same center in the years 2003-2007.

RESULTS

In 2008, 141 women and 209 men with a mean age of 48.6 years (range 13-71 years) were on the waiting list. In the years 2003-2007, 98 women and 226 men with a mean age of 54.3 years (range 16-78 years) received renal transplants. One hundred six patients on the waiting list for renal transplantation had to undergo coronary angiography. There is no upper age limit for donors or recipients in our program. Mean age at admission on the waiting list was 48.6 years (range 13-71 years). Mean age at transplantation was 54.3 years (range 16-78 years) in our center. Most of these patients were asymptomatic but presented a risk profile that included diabetes mellitus, severe general atherosclerosis, a pathologic ergometric test, or abnormal myocardial scintigraphy. Only in 1 case could coronary heart disease be excluded. Seventy patients (20%) suffered from mild to moderate coronary heart disease without the need for intervention. In 5 patients (1.4%) coronary bypass surgery was necessary due to severe 3-vessel coronary heart disease. In 2 cases (0.6%) replacement of the aortic valve was performed because of aortic valvular stenosis. Coronary angioplasty without implantation of stents was done in 2 patients (0.6%). Twenty-two patients (6.8%) were treated with implantation of bare metal stents and 6 patients (1.7%) with drug-eluting stents. After renal transplantation, 22 patients (6.8%) suffered from peripheral arterial occlusive disease. In 58 patients, coronary heart disease was documented by angiography. 16 patients (4.9%) had 1-vessel disease, 23 patients (7%) 2-vessel disease, and 19 patients (5.8%) 3-vessel disease. Myocardial infarction was documented in 18 patients (5.5%) before and in 5 patients (1.5%) after renal transplantation. Bare metal stent implantation was performed in 6 patients (1.8%) after transplantation. One patient received a drug-eluting stent after renal transplantation. In the years 2003-2007, 22 patients underwent coronary bypass surgery before kidney transplantation.

CONCLUSION

The prevalence of coronary heart disease is high in patients on the waiting list and after renal transplantation. The majority of these patients are clinically asymptomatic. One-third of the patients with coronary heart disease had to be treated invasively. Nevertheless, many diabetic patients are very sick from multiple complications after the waiting time, making theme unsuitable for transplantation.

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.

A prospective trial of a steroid-free/calcineurin inhibitor minimization regimen in human leukocyte antigen (HLA)-identical live donor renal transplantation

BACKGROUND

Few prospective trials in human leukocyte antigen (HLA) identical living donor (LD) renal transplantation exist. This prospective study evaluated a corticosteroid (CS)-free, calcineurin inhibitor (CNI) minimization immunosuppressive regimen in HLA-identical LD renal transplant recipients.

METHODS

Twenty HLA-identical LD recipients were prospectively enrolled. Immunosuppression included mycophenolate mofetil (MMF) (2 g/day), tacrolimus (target trough 4-8 ng/mL), sirolimus (target trough 6-10 ng/mL), and no pre- or postoperative steroids. In the absence of prior rejection, tacrolimus was discontinued at posttransplant day 120 and sirolimus at 1 year, leaving patients on MMF monotherapy.

RESULTS

Tacrolimus was successfully withdrawn in 94% of patients (16/17). One hundred percent (15/15) of patients who reached 1-year posttransplant had sirolimus discontinued. Ninety-four percent (17/18) of patients remain off CSs. Mean serum creatinine at 6, 12, and 24 months were 1.38+/-0.32, 1.35+/-0.37, and 1.25+/-0.29 mg/dL; corresponding mean calculated creatinine clearance estimates were 70+/-18, 73+/-17, and 72+/-15 mL/min. Acute cellular rejection, chronic allograft nephropathy, and CNI toxicity were not observed. Death-censored graft survival was 100% at last follow-up.

CONCLUSIONS

A CS-free, CNI minimization immunosuppressive regimen with weaning to MMF monotherapy provides excellent renal function, graft survival, and patient survival in HLA-identical LD renal transplant recipients.

Early conversion from cyclosporine to tacrolimus increases renal graft function in chronic allograft nephropathy at BANFF stages I and II

Switching from cyclosporine to tacrolimus without steroid pulse was suggested as a therapeutic option in chronic allograft nephropathy (CAN). Thirty-one renal transplant recipients with CAN were prospectively converted from cyclosporine to tacrolimus (group A), in parallel 31 matched cyclosporin A (CsA) patients (group B) without CAN were followed up for 30 months. In six matching patients of groups A and B inulin and para-aminohippurate (PAH)-clearances and mycophenolate were measured over a span of 3 months. Transplant biopsies of group A were scored according to BANFF. While group A presented with transplant dysfunction compared with group B before switching (2.7 +/- 0.16 mg/dl vs. 1.7 +/- 0.09 mg/dl; P < 0.001), transplant function was equal 30 months later: it ameliorated in group A (2.0 +/- 0.18 mg/dl vs. 2.7 +/- 0.16 mg/dl; P < 0.001) and decreased in group B (1.9 +/- 0.13 mg/dl vs. 1.7 +/- 0.09 mg/dl, P < 0.05). Especially, patients with biopsy scores I and II according to BANFF benefited from tacrolimus. Within 3 months, mycophenolate acid (MPA) levels increased under tacrolimus (P < 0.05) whereas inulin and PAH-clearances remained unchanged. At switching, antihypertensive treatment was more intense in group B, but this difference evened out. Adverse side effects were more frequent under tacrolimus. Patients with mild to moderate CAN significantly benefited from switching to tacrolimus. Increased MPA-levels under tacrolimus might have contributed to this effect.

Cyclosporine A and Rapamycin induce in vitro cholesteryl ester transfer protein activity, and suppress lipoprotein lipase activity in human plasma

PURPOSE

Cyclosporine A (CsA), Rapamycin (RAPA), Tacrolimus (FK-506) and Mycophenolate mofetil (MMF) are immunosuppressants that are widely used in solid organ transplant patients. However, some of these drugs have been reported to cause dyslipidemia in patients. Our aim was to determine the effects of these drugs on in vitro cholesteryl ester transfer protein (CETP), hepatic lipase (HL) and lipoprotein lipase (LPL) activity within human plasma.

METHODS

We measured CETP activity in human normolipidemic plasma with and without drug treatment, by measuring the incorporation of labeled cholesteryl ester into lipoproteins. To further confirm the result, we also measured recombinant CETP (rCETP) activity with and without drug treatment. We measured HL and LPL activity in post-heparin normal human plasma in the presence and absence of the drugs by measuring the release of fatty acids from radiolabeled triolein.

RESULTS

We found an increase in CETP activity in human normolipidemic plasma and rCETP treated with CsA and RAPA. By contrast, CETP activity was not altered significantly in the presence of FK-506 and MMF. LPL activity in post-heparin normal human plasma was suppressed following the co-incubation with CsA, RAPA, FK-506 or MMF whereas HL activity remained unaffected.

CONCLUSIONS

The increase in CETP activity and suppression in LPL activity following CsA and RAPA treatment observed in the present study may be associated with elevated LDL cholesterol levels and hypertriglyceridemia seen in patients administered these drugs.

The role of tacrolimus in renal transplantation

Tacrolimus gained FDA approval for use in liver transplantation in 1994 and, approximately 3 years later, was approved for the prevention of acute rejection in kidney transplantation. Over the last decade tacrolimus has become the calcineurin inhibitor of choice for the prevention of rejection in renal transplantation. The objective of this study was to provide a review and update of the literature on the use of tacrolimus in renal transplantation. Numerous clinical trials have shown tacrolimus to be superior to cyclosporine in the prevention of acute rejection and recent trials have demonstrated superiority of tacrolimus over cyclosporine in terms of allograft survival. Post-transplant diabetes remains more common with tacrolimus than cyclosporine, despite lower doses of both tacrolimus and corticosteroids. A novel once-daily dosage form of tacrolimus has recently been developed and is approved for use in Europe. Tacrolimus remains an important immunosuppressant for the prevention of acute rejection. The prolonged-release formulation may improve compliance and possibly long-term outcomes.

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.

Efficacy and safety of tacrolimus compared with ciclosporin A in renal transplantation: three-year observational results

BACKGROUND

The European tacrolimus versus ciclosporin A microemulsion (CsA-ME) renal transplantation study showed that tacrolimus was significantly more effective in preventing acute rejection and had a superior cardiovascular risk profile at 6 months.

METHODS

The endpoints of this investigator-initiated, observational, 36-month follow-up were acute rejection incidence rates, rates of patient and graft survival and renal function. An additional analysis was performed using the combined endpoints BPAR, graft loss and patient death. Data available from the original ITT population (557 patients; 286 tacrolimus and 271 CsA-ME) were analysed.

RESULTS

A total of 231 tacrolimus and 217 CsA-ME patients participated. At 36 months, Kaplan-Meier-estimated BPAR-free survival rates were 78.8% in the tacrolimus group and 60.6% in the CsA-ME group, graft survival rates were 88.0% and 86.9% and patient survival rates were 96.6% and 96.7%, respectively. The estimated combined endpoint-free survival rate was 71.4% with tacrolimus and 55.4% with CsA-ME (P <or= 0.001, chi-square test). Significantly more CsA-ME patients crossed over to tacrolimus during the 3-year follow-up: 21.2% versus 2.6%, P <or= 0.0001, chi-square test. Most patients in the tacrolimus arm discontinued steroids and received monotherapy and fewer tacrolimus patients remained on a triple regimen. Mean serum creatinine concentration was 145.4 +/- 90.9 micromol/L with tacrolimus and 149.0 +/- 92.1 micromol/L with CsA-ME. Significantly more CsA-ME patients had a classified cholesterol value >6 mmol/L (26.3% versus 12.6%, P <or= 0.0003, chi-square test).

CONCLUSIONS

Patients treated with tacrolimus had significantly higher combined endpoint-free survival rates and lower acute rejection rates with less immunosuppressive medication at 36 months.

CYP3A5 and CYP3A4 but not MDR1 single-nucleotide polymorphisms determine long-term tacrolimus disposition and drug-related nephrotoxicity in renal recipients

The impact of CYP3A and MDR1 gene single-nucleotide polymorphisms on long-term tacrolimus disposition and drug-related toxicity has not been assessed. A study was performed in 95 genotyped recipients by measuring (12 and 4 h) concentration-time curves on day 7; 3, 6 months; 1, 2, 3, 4, and 5 years after transplantation. In contrast to recipients carrying the CYP3A4*1/CYP3A5*1 or CYP3A4*1B/CYP3A5*1 genotypes, dose-corrected tacrolimus exposure almost doubled over 5 years in patients with the CYP3A4*1/ CYP3A5*3 genotype (AUC(0-12 h): from 41.7+/-18.7 to 80+/-39.2 ng h/ml/mg; P<0.05), whereas apparent oral steady-state clearance and dose requirements significantly decreased accordingly. The CYP3A4*1/CYP3A5*1 and CYP3A4*1B/CYP3A5*1 genotypes were significantly more frequently associated with the development of biopsy-proven tacrolimus-related nephrotoxicity than the CYP3A4*1/ CYP3A5*3 genotype (37.5 vs 11.2%; P=0.03 and 42.8 vs 11.2%; P=0.02). The lack of a time-related increase in dose-corrected tacrolimus exposure observed with the CYP3A4*1/CYP3A5*1 and CYP3A4*1B/CYP3A5*1 genotypes is associated with tacrolimus-related nephrotoxicity, possibly as a result of higher concentrations of toxic metabolites.

The Pharmacodynamic Effects of Sirolimus andSirolimus-Calcineurin Inhibitor Combinations on Macrophage Scavenger and Nuclear Hormone Receptors

BACKGROUND

Sirolimus (SIR) alone or in combination with cyclosporine (CsA) or tacrolimus (TAC) are used in solid organ transplantation, but uncertainty remains regarding their respective atherogenic potentials.

METHODS

THP-1 cells were cultured as macrophages and then treated with plasma trough and peak concentration doses of SIR, SIR/CsA or SIR/TAC to assess the time- and dose-dependent mRNA or protein expression of selected atherogenic genes. The selected atherogenic genes included: the macrophage scavenger receptors (MSRs) CD36, CD68, scavenger receptor (SR)-A, SR-BII, and LOX-1; the nuclear hormone receptors peroxisome proliferator activated receptor gamma (PPARgamma) and liver-X-receptor alpha (LXRalpha); and the cholesterol efflux transporter (ABCA-1).

RESULTS

SIR-mediated changes in mRNA included the upregulation of ABCA1, downregulation of CD68, SR-A and SR-BII, and concentration- and/or time-dependent effects on CD36, LOX-1, PPARgamma, and LXRalpha that did not translate into significant protein changes. With SIR/CsA, the protein expressions of PPARgamma and ABCA-1 were downregulated at 8 h. In contrast, with SIR/TAC, PPARgamma, and ABCA-1 protein expressions were upregulated at 8 h.

CONCLUSIONS

Combination results differed from findings with SIR alone, supporting the observed clinical phenotype with calcineurin inhibitors. These findings may provide a rationale for the development of novel drug delivery strategies to mitigate adverse pharmacodynamic responses.

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.

Impact of cyclosporine reduction with MMF: a randomized trial in chronic allograft dysfunction. The 'reference' study

Long-term use of calcineurine inhibitors (CNIs) may contribute to the development of chronic allograft dysfunction (CAD). We investigate the impact of the introduction of MMF combined with cyclosporine (CsA) 50% dose reduction. An open, randomized, controlled, multicenter, prospective study was conducted in 103 patients, receiving a CsA-based therapy with a serum creatinine between 1.7-3.4 mg/dL, more than 1 year after transplantation. They were randomized to receive MMF with half dose of CsA (MMF group) or to continue their maintenance CsA dose (control group). A total of 96 weeks after randomization, the evolution of renal function assessed by regression line analysis of 1/SeCr improved in the MMF group (positive slope) vs. the control group (negative slope), 4.2 x 10(-4) vs. -3.0 x 10(-4), respectively (p < 0.001). Concurrently, the absolute renal function improved significantly in the MMF group. No episode of biopsy-proven acute rejection occurred. One patient in each group lost his graft because of biopsy-proven chronic allograft nephropathy. There was a significant decrease of triglycerides level in the MMF group. Anemia and diarrhea were statistically more frequent in the MMF group. In CAD, the reduction of CsA in the presence of MMF results in significant improvement in renal function during a 2-year follow-up.

Morbidity and mortality of cardiac surgery following renal transplantation

BACKGROUND

With improved survival following renal transplantation, the number of patients undergoing cardiac surgery has increased. The purpose of this study was to review the morbidity, mortality, and allograft function in renal transplant patients undergoing major cardiac surgery.

METHODS

Retrospective database review of consecutive renal transplant patients undergoing cardiac surgery from 1987 to 2002. Patients requiring dialysis (D) before cardiac surgery versus those with stable renal transplants (ND) were compared.

RESULTS

Cardiac surgery was performed in 46 patients during the study period. Twenty patients (42%) required dialysis (D) before surgery while 26 (58%) had stable allograft function (ND). Among patients who had stable allograft function prior to surgery, there was no allograft loss. In the ND group, preoperative and discharge creatinine levels were 2.17 +/- 1.0 and 2.4 +/- 1.5 mg/dL, respectively. All operative deaths occurred in the dialysis dependent group. The 30-day and 3-year survival, respectively was 80% and 20% in the D group compared to 100% and 69% amongst the ND group (p </= 0.01). Infectious complications consisted of pneumonia and sepsis each in 8.5% and of deep sternal wound infection in 4.3% of the entire group.

CONCLUSIONS

(1) Morbidity and mortality of cardiac surgery in renal transplant patients with stable allograft function is low and stable allograft function can be maintained without allograft loss. (2) Mortality following cardiac surgery is significantly higher among renal transplant patients who become dialysis dependent and intermediate-term survival is poor.

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.

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.