Use of LCP-Tacrolimus (LCPT) in Kidney Transplantation: A Delphi Consensus Survey of Expert Clinicians.

BACKGROUND LCPT (Envarsus XR®) is a common once-daily, extended-release oral tacrolimus formulation used in kidney transplantation. However, there are minimal evidence-based recommendations regarding optimal dosing and treatment in the de novo and conversion settings. MATERIAL AND METHODS Using Delphi methodology, 12 kidney transplantation experts with LCPT experience reviewed available data to determine potential consensus topics. Key statements regarding LCPT use were generated and disseminated to the panel in an online Delphi survey. Statements were either accepted, revised, or rejected based on the level of consensus, perceived strength of evidence, and alignment with clinical practice. Consensus was defined a priori as ≥75% agreement. RESULTS Twenty-three statements were generated: 14 focused on de novo LCPT use and 9 on general administration or LCPT conversion use. After 2 rounds, consensus was achieved for 11/14 of the former and 7/9 of the latter statements. In a de novo setting, LCPT was recognized as a first-line option based on its safety and efficacy compared to immediate-release tacrolimus. In particular, African Americans and rapid metabolizer populations were identified as preferred for first-line LCPT therapy. In a conversion setting, full consensus was achieved for converting to LCPT to address neurological adverse effects related to immediate-release tacrolimus and for the time required (approximately 7 days) for steady-state LCPT trough levels to be reached. CONCLUSIONS When randomized clinical trials do not replicate current utilization patterns, the Delphi process can successfully generate consensus statements by expert clinicians to inform clinical decision-making for the use of LCPT in kidney transplant recipients.

Baseline living-donor kidney volume and function associate with 1-year post-nephrectomy kidney function.

Living donors may develop kidney dysfunction more often than equally healthy populations. The purpose of this study was to determine whether computed tomography-assessed remaining kidney volume indexed to body surface area (RKV/BSA) was associated with 1-year post-nephrectomy renal function independent of baseline renal function. Using multivariable regression, we modeled 1-year estimated glomerular filtration rate (eGFR) and eGFR <60 mL /min/1.73 m2 and considered pre-determined baseline eGFR subgroups in 151 consecutive donors. Mean ± SD baseline age, eGFR, RKV, BSA, and RKV/BSA were 38 ± 11 years, 97 ± 16 mL/min/1.73 m2 , 153 ± 29 mL, 1.9 ± 0.2 m2 , and 80.0 ± 12.8 ml/m2 , respectively; 50% were female and 94% were white. Mean baseline eGFR was greater with increasing RKV/BSA tertiles (92 ± 14, 97 ± 16, 107 ± 16 mL/min/1.73 m2 ; P < 0.001). Post-nephrectomy eGFR remained separated by RKV/BSA tertiles. At baseline, each SD greater RKV/BSA and eGFR was independently associated with higher adjusted 1-year eGFR by 2.4 and 9.2 mL/min/1.73 m2 . Each SD greater age associated with 2.2 mL/min/1.73 m2 lower adjusted 1-year eGFR. Adjusted odds of 1-year eGFR <60 increased significantly for donors with RKV/BSA <80 mL/m2 . With baseline eGFR <90, probability of 1-year eGFR <60 increased to >80% with decreasing RKV/BSA values below 80 mL/m2 . Those with baseline eGFR >100 rarely developed 1-year eGFR <60 if RKV/BSA remained >60 mL/m2 . RKV/BSA independently associated with 1-year eGFR <60, especially with lower baseline eGFRs. Additional studies should evaluate the predictive utility of this measure and its potential role in donor evaluations and informed consent.

A randomized, phase 2 study of ASP0113, a DNA-based vaccine, for the prevention of CMV in CMV-seronegative kidney transplant recipients receiving a kidney from a CMV-seropositive donor.

Cytomegalovirus (CMV) is a latent infection in most infected individuals, but can be pathogenic in immunocompromised kidney transplant recipients. ASP0113 is a DNA-based vaccine for the prevention of CMV-related mortality and end-organ disease in transplant recipients. The efficacy, safety, and immunogenicity of ASP0113 was assessed in a phase 2, double-blind, placebo-controlled study in CMV-seronegative kidney transplant recipients receiving a kidney from a CMV-seropositive donor. Transplant recipients were randomized (1:1) to receive 5 doses of ASP0113 (5 mg; n = 75) or placebo (n = 74) on Days 30/60/90/120/180 posttransplant, and they received prophylactic valganciclovir/ganciclovir 10-100 days posttransplant. The primary endpoint was the proportion of transplant recipients with CMV viremia ≥1000 IU/mL from Day 100 through to 1 year after the first study vaccine injection. There was no statistically significant difference in the primary endpoint between the ASP0113 and placebo groups (odds ratio 0.79, 95% confidence interval 0.43-1.47; P = .307). There were similar numbers of transplant recipients with treatment-emergent adverse events between groups; however, more transplant recipients reported injection site pain in the ASP0113 group compared with placebo. ASP0113 did not demonstrate efficacy in the prevention of CMV viremia in this CMV-seronegative kidney transplant population, but demonstrated a safety profile similar to placebo. ClinicalTrials.gov registration number: NCT01974206.

Optimizing everolimus exposure when combined with calcineurin inhibitors in solid organ transplantation.

The mammalian target of rapamycin (mTOR) inhibitor everolimus is a narrow therapeutic index drug for which optimal exposure levels are essential. The consistent pharmacokinetic profile of everolimus allows trough concentration (C0) measurement to be an appropriate and reliable index for therapeutic drug monitoring (TDM). Exposure-response analyses of data from early fixed-dose trials demonstrated that rates of biopsy-proven acute rejection (BPAR) are significantly higher if everolimus C0 declines below 3 ng/mL, an observation confirmed in subsequent concentration-controlled trials. Evidence for the most favorable upper limit is less clear but with reduced-exposure calcineurin inhibitor (CNI) therapy, an upper limit of 8 ng/mL appears to balance efficacy and safety outcomes. The recommended C0 range is 3-8 ng/mL in kidney, liver and heart transplantation patients, based on LC-MS/MS monitoring in whole blood. Randomized clinical trials based on this target range have demonstrated rates of BPAR comparable to a regimen of mycophenolic acid with standard-exposure CNI. Everolimus exhibits moderate intrapatient pharmacokinetic variability, and it can be challenging to maintain stable concentrations within target range in some individuals. Many factors can influence everolimus exposure for a given dose, including hepatic function, activity of the drug efflux pump P-glycoprotein, the rate of everolimus metabolism, drug-drug interactions (predominantly with CYP3A4 and P-glycoprotein inhibitors, including cyclosporine), intake of fatty food, and patient adherence to the prescribed regimen. Trough concentration levels should be monitored 4-5days after the first dose and after any change in everolimus dose, with additional monitoring in response to any change in concomitant medication or other clinical circumstances which could alter everolimus exposure. Although LC-MS/MS is the gold standard for everolimus monitoring, various immunoassays are widely used due to their relative simplicity and lower cost, and results can show considerable discrepancies with reference methods due to issues such as interassay variability and cross-reactivity. Method standardization will be important in the future to improve the consistency and reproducibility of results between centers. In conclusion, based on an extensive program of clinical trials, the optimal exposure range for everolimus in combination with reduced-exposure CNI therapy has been established and can be achieved in most transplant recipients through careful, planned TDM.

Early Results of Pilot Study Using Hepatitis C Virus (HCV) Positive Kidneys to Transplant HCV Infected Patients with End-Stage Renal Disease Allowing for Successful Interferon-Free Direct Acting Antiviral Therapy after Transplantation.

INTRODUCTION: Hepatitis C virus (HCV) infection in kidney transplant (KTX) patients reduces long-term patient and graft survival. Direct-acting antivirals (DAA) are > 90% effective in achieving sustained viral response (SVR); however, DAAs are not routinely available to patients with end-stage renal disease (ESRD). The University of Utah Transplant Program developed a protocol to allow HCV-positive potential KTX recipients to accept HCV-positive donors' kidneys. Three months after successful KTX, they were eligible for DAA therapy. METHODS: HCV-positive patients approved for KTX by the University of Utah Transplant Selection Committee were eligible to be enrolled in this study. Patients consented for the use of HCV-positive donor organs. Three to six months after successful KTX, these patients were treated for HCV with interferon-free direct-acting antiviral regimens according to viral genotype and prior treatment experience. RESULTS: Between 2014-2015, 12 HCV-positive patients were listed for KTX. Eight patients were kidney only eligible, seven patients received HCV-positive deceased donor kidneys, and one received an HCV-negative organ. Currently, six patients have completed treatment, all have achieved sustained viral response (SVR), and one patient is currently awaiting treatment. All seven patients have functioning kidney grafts. Wait time for KTX was reduced amongst all blood groups from an average of 1,350 days to only 65 days. CONCLUSIONS: HCV-positive patients with ESRD can successfully receive an HCV-positive donor's kidney. Once transplanted, these patients can receive DAA therapy and achieve SVR. Use of HCV-positive organs reduced time on the waitlist by greater than three years and expanded the donor organ pool.

Cardiovascular Risk Assessment and Management in Prerenal Transplantation Candidates.

Cardiovascular (CV) assessment in prerenal transplant patients varies by center. Current guidelines recommend stress testing for candidates if ≥ 3 CV risk factors exist. We evaluated the CV assessment and management in 685 patients referred for kidney transplant over a 7-year period. All patients had CV risk factors, and the most common cause of end-stage renal disease was diabetes. Thirty-three percent (n = 229) underwent coronary angiography. The sensitivity of stress testing to detect obstructive coronary artery disease (CAD) was poor (0.26). Patients who had no CAD, nonobstructive CAD, or CAD with intervention had significantly higher event-free survival compared with patients with obstructive CAD without intervention. There were no adverse clinical events (death, myocardial infarction, stroke, revascularization, and graft failure) within 30 days post-transplant in patients who had preoperative angiography (n = 77). Of the transplanted patients who did not have an angiogram (n = 289), there were 8 clinical events (6 myocardial infarctions) in the first 30 days. In conclusion, our results indicate that stress testing and usual risk factors were poor predictors of obstructive CAD and that revascularization may prove beneficial in these patients.

Long-term dosing patterns of enteric-coated mycophenolate sodium or mycophenolate mofetil with tacrolimus after renal transplantation.

MORE was a four-yr, prospective, observational study at 40 transplant centers in the US. Data were analyzed to evaluate changes in mycophenolic acid (MPA) dosing over time in 904 de novo kidney transplant recipients receiving enteric-coated mycophenolate sodium (EC-MPS, n = 616) or mycophenolate mofetil (MMF, n = 288) with tacrolimus. Induction therapy and steroid treatment were similar in the two subpopulations. The proportion of patients receiving the maximal recommended MPA dose was 80.5%, 43.9%, 39.2%, 34.6%, and 30.1% at baseline and years 1, 2, 3, and 4, respectively. More patients received the maximal recommended MPA dose with EC-MPS vs. MMF at month 1 (79.2% vs. 71.7%, p = 0.016), month 3 (68.5% vs. 56.9%, p = 0.001), and month 6 (52.9% vs. 44.0%, p = 0.028). Multivariate analysis showed the risk of biopsy-proven acute rejection, graft loss or death to be similar for EC-MPS vs. MMF. Estimated glomerular filtration rate (GFR) was similar with EC-MPS vs. MMF at all time points. There were no significant differences in any category of adverse event between the EC-MPS and MMF cohorts during follow-up, including gastrointestinal events. In conclusion, MPA dose was maintained more effectively in the first six months after kidney transplantation using EC-MPS vs. MMF, without an increase in adverse events.

Focus on mTOR inhibitors and tacrolimus in renal transplantation: pharmacokinetics, exposure-response relationships, and clinical outcomes.

Mammalian target of rapamycin (mTOR)-inhibitor-containing immunosuppressive regimens have been developed as part of calcineurin inhibitor (CNI) minimization/withdrawal strategies for renal transplant recipients, with the goal of avoiding CNI-associated nephrotoxicity. This review focuses on the pharmacokinetic interactions and exposure-response relationships of mTOR inhibitors and tacrolimus (TAC), the most widely used CNI. We also discuss key randomized clinical studies that have evaluated use of this combination in renal transplantation. Pharmacokinetic studies have shown that mTOR inhibitors, everolimus (EVR) and sirolimus (SRL), have a large intra- and inter-patient variability in drug exposure, and narrow therapeutic windows (trough levels [C0] 3-8 ng/mL and 5-15 ng/mL, respectively). Consequently, routine therapeutic drug monitoring of EVR and SRL is recommended to optimize efficacy and minimize toxicity in individual patients. As there is a good correlation between C0 and area under the curve (AUC), C0 can be used as a convenient and reliable measure of mTOR drug exposure. Clinical data on the use of EVR or SRL in TAC minimization strategies in renal transplantation are limited. Available evidence suggests that treatment with EVR allows early and substantial TAC minimization when used with basiliximab induction and corticosteroids, to achieve good renal function without compromising efficacy or safety. However, data comparing this combination with other regimens are lacking. Results with SRL are more mixed. SRL in combination with reduced TAC has been shown to provide less nephrotoxicity than the SRL/standard TAC combination, with comparable efficacy and safety. However, this approach has been shown to be inferior to other regimens in terms of patient/graft survival and biopsy-proven acute rejection (vs MMF/TAC) as well as renal function (vs MMF/TAC and SRL/MMF). Further studies are needed to define the therapeutic window for TAC when used in combination with mTOR inhibitors, evaluate EVR/reduced TAC versus other regimens, assess long-term outcomes, and determine efficacy and safety in high-risk patients.

Tacrolimus exposure in the real world: an analysis from the Mycophenolic acid Observational REnal transplant study.

Tacrolimus exposure and renal function data to 36 months post-transplant were analyzed from the prospective, observational Mycophenolic acid Observational REnal transplant (MORE) registry in which de novo kidney transplant patients were managed according to local practice. Tacrolimus trough (C0 ) concentration at month 12 was stratified as low (<6 ng/mL), moderate (6-8 ng/mL), or high (>8 ng/mL) in 724 patients. Estimated glomerular filtration rate (eGFR) was stratified as low (<60 mL/min/1.73 m(2) ) or high (≥60 mL/min/1.73 m(2) ). High tacrolimus C0 (>8 ng/mL) was observed in 47.7%, 34.1%, 26.8%, and 26.7% of patients at baseline and months 12, 24, and 36, respectively. Biopsy-proven acute rejection was similar to month 36 regardless of tacrolimus C0 category at month 12. Tacrolimus C0 >8 ng/mL vs. <6 ng/mL at month 12 was predictive of low eGFR at month 24 (p = 0.023) with a nonsignificant trend at month 36 (p = 0.085). Infections (p < 0.013) and BK virus infection (p < 0.001) were most frequent in the low tacrolimus C0 cohort. Neutropenia was most frequent in the high tacrolimus C0 category (p = 0.010). In conclusion, over a quarter of patients were exposed to high tacrolimus C0 to 36 months post-transplant. Tacrolimus exposure did not affect rejection risk, but tacrolimus C0 >8 ng/mL at month 12 was predictive of subsequent low eGFR compared to C0 <6 ng/mL.

Long-term outcomes in African American kidney transplant recipients under contemporary immunosuppression: a four-yr analysis of the Mycophenolic acid Observational REnal transplant (MORE) study.

Mycophenolic acid Observational REnal transplant (MORE) was a prospective, observational study of de novo kidney transplant patients receiving mycophenolic acid (MPA). Four-yr data on 904 patients receiving tacrolimus and enteric-coated mycophenolate sodium (EC-MPS) or mycophenolate mofetil (MMF) were analyzed to evaluate immunosuppression and graft outcomes in African American (AA, n = 218) vs. non-AA (n = 686) patients. Mean tacrolimus dose was higher in AA vs. non-AA patients but mean tacrolimus trough concentration was similar. Use of the recommended MPA dose in AA patients decreased from 78.9% at baseline to 33.1% at year 3. More AA patients received the recommended MPA dose with EC-MPS than MMF at month 6 (56.2% vs. 35.7%, p = 0.016) and month 36 (46.6% vs. 16.7%, p = 0.029), with no safety penalty. Significantly, more AA patients received corticosteroids than non-AA patients. Biopsy-proven acute rejection was higher in AA vs. non-AA patients (18.9% vs. 10.7%, p = 0.003), as was graft loss (10.9% vs. 4.4%, p = 0.003); differences were confirmed by Cox regression analysis. Patient survival was similar. Estimated GFR was comparable in AA vs. non-AA patients. Kidney allograft survival remains lower for AA vs. non-AA recipients even under the current standard of care.

Outcomes in ethnic minority renal transplant recipients receiving everolimus versus mycophenolate: comparative risk assessment results from a pooled analysis.

BACKGROUND: Everolimus (EVR) has demonstrated good efficacy after renal transplantation. Racial disparities in clinical outcomes after de novo renal transplantation are well documented; whether the efficacy of EVR varies based on recipient ethnicity is unknown. We conducted a comparative risk assessment of EVR by ethnicity. METHODS: Data on 2004 renal transplant recipients from three EVR studies were pooled to identify the impact of ethnicity on efficacy outcomes across EVR dosing groups and control groups. Ethnic groups compared were African Americans, non-U.S. blacks, Asians, Hispanics, and Caucasians. EVR groups received either 1.5 or 3 mg per day, with either standard-dose cyclosporine or reduced-dose cyclosporine. Control groups received mycophenolic acid (MPA) with standard-dose cyclosporine. Composite efficacy failure endpoint was graft loss, death, biopsy-proven acute rejection, or lost to follow-up. Adjusted odds ratios were calculated using a logistic regression model. RESULTS: The proportion of renal transplant recipients who met the composite endpoint was African Americans (46%), non-U.S. black (35%), Caucasian (31%), Hispanic (28%), and Asian (25%). The odds of meeting the composite endpoint were significantly (P=0.0001) greater for African Americans versus Caucasians but did not differ among the other ethnic groups (ethnic groups were only compared with Caucasians). EVR and MPA were associated with similar efficacy among each of the ethnic groups. CONCLUSION: In this pooled data analysis in more than 2000 renal transplant recipients, EVR versus MPA resulted in similar composite endpoint incidence events across ethnicities. Consistent with previously published data, African Americans had poorer clinical outcomes. EVR is efficacious regardless of ethnicity.

Outcomes in African American kidney transplant patients receiving tacrolimus and mycophenolic acid immunosuppression.

BACKGROUND: Prospective data regarding immunosuppression and rejection in African American patients receiving modern immunosuppressive regimens are sparse. METHODS: One-year data were analyzed from 901 tacrolimus-treated de novo kidney transplant patients in the prospective Mycophenolic Acid Observational Renal Transplant registry. RESULTS: Mean tacrolimus dose was significantly higher in African Americans (n=217) versus non-African Americans (n=684), but mean tacrolimus trough concentrations were similar. The proportion of patients receiving mycophenolic acid dose equal to or more than 2000 mg per day (mycophenolate mofetil equivalents) was significantly higher with enteric-coated mycophenolate sodium versus mycophenolate mofetil at month 6 among African Americans and at month 3 in non-African Americans, but rates of acute rejection and adverse events (including gastrointestinal events) were similar. The 1-year incidence of biopsy-proven acute rejection (BPAR) was 14.1% in African Americans versus 7.5% in non-African Americans. On multivariate analysis, African American ethnicity was associated with a higher risk of BPAR (hazard ratio, 1.93; 95% confidence interval, 1.19-3.09; P=0.007). Mean (standard deviation) glomerular filtration rate at month 12 estimated by the Chronic Kidney Disease Epidemiology Collaboration formula was 59.2 (22.2) mL/min/1.73 m in African Americans versus 58.8 (19.9) mL/min/1.73 m in non-African Americans (confidence interval of the difference, -3.4 to 4.3; P=0.83). CONCLUSION: This observational study confirms that African Americans require higher doses of tacrolimus to achieve target trough concentrations and are more likely to experience BPAR during the first year after kidney transplantation despite modern immunosuppression regimens. In our 1-year study, this was not associated with significantly inferior graft survival.

Acute rejection characteristics from a prospective, randomized, double-blind, placebo-controlled multicenter trial of early corticosteroid withdrawal.

BACKGROUND: This report characterizes acute rejection and rejection outcomes in subjects randomized to continuous corticosteroid therapy (CCS) or early corticosteroid withdrawal (CSWD; 7 days after transplantation) in the Astellas Blinded CSWD Trial. METHODS: The Astellas Blinded CSWD Trial was a 5-year, prospective, multicenter, randomized, double-blind trial of early CCS withdrawal in 386 kidney transplant recipients (195 CCS and 191 CSWD). Tacrolimus and mycophenolate mofetil were required as well as either rabbit antithymocyte globulin or interleukin-2 receptor antibody induction. Biopsy-confirmed acute rejection (BCAR) was grade 1A or higher by Banff criteria. This report also provides borderline changes (BL) that did not meet Banff grade 1A included with BCAR (BCAR+BL). RESULTS: BCAR+BL was 25 (12.8%) in CCS group and 42 (22.0%) in CSWD group (P=0.022). Early BCAR+BL (first 90 days after transplantation) was less frequent in CCS (n=5 [2.6%]) than in CSWD (n=22 [11.5%]; P<0.001). Among non-African-American subjects, early BCAR+BL occurred more often in CSWD (n=20 [12.7%]) versus CCS (n=2 [1.3%]; P<0.001). Late acute rejection (>2 years) occurred more often in African-American subjects in CCS (n=5 [13.9%]) than in CSWD (n=0; P=0.056). Risk factors were CSWD (hazard ratio [HR], 4.72; P<0.002) and human leukocyte antigen mismatch (HR, 1.48; P<0.005) for early BCAR+BL and CSWD (HR, 1.9; P<0.02), human leukocyte antigen mismatch (HR, 1.2; P<0.01), and age (HR, 0.97; P<0.002) for 5-year rejection. The HR for graft loss associated with BCAR+BL was 8.8. CONCLUSIONS: BCAR+BL may occur more frequently during the early period after transplantation under an early CSWD regimen with tacrolimus plus induction compared with CCS, particularly among non-African-Americans.

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.

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

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

Association of clinical events with everolimus exposure in kidney transplant patients receiving reduced cyclosporine.

BACKGROUND: The association between clinical events and everolimus exposure in patients receiving reduced-exposure calcineurin inhibitor therapy is poorly explored. METHODS: In a pre-planned, descriptive analysis of data from a randomized controlled trial, events were correlated with everolimus trough concentrations in 556 newly transplanted kidney transplant patients receiving everolimus with reduced-exposure cyclosporine (CsA) and steroids. Influence of everolimus exposure on clinical events was stratified according to predefined time-normalized concentrations. RESULTS: The incidence of treated biopsy-proven acute rejection and graft loss at month 12 was highest in patients with everolimus <3 ng/mL (36.4% and 28.6%, respectively, vs. 9.1-15.3% and 0.9-5.0% with higher concentration ranges). A higher mortality rate was observed in patients with an everolimus trough concentration ≥ 12 ng/mL (10.0% vs. 1.7-5.6% with lower concentration ranges). The lowest rates of renal dysfunction (defined as poor renal function [estimated GFR, serum creatinine] or proteinuria), wound healing events, peripheral edema, new-onset diabetes mellitus, hypercholesterolemia and hypertriglyceridemia were generally observed with everolimus trough concentration in the range 3-8 ng/mL and CsA <100 ng/mL. Proteinuria occurred most frequently in patients with very low or very high everolimus trough concentrations. CONCLUSIONS: These results support an exposure-response relationship between clinical events and everolimus trough concentrations in kidney transplant patients receiving reduced-exposure CsA.

Effect of donor kidney volume on recipient outcome: does the "dose" matter?

BACKGROUND: The effect of donor kidney volume on recipient kidney function has not been fully evaluated. METHODS: We performed a prospective analysis of 125 consecutive living kidney donor/recipient pairs. Donor kidney volume was calculated from pretransplantation computed tomography angiograms using a three-dimensional computerized volume method. Cortical volume was calculated from arterial phase and total volume from delayed phase. Because weight is a surrogate marker for metabolic demands, we looked at the "volume dose" by calculating the ratio of donor kidney volume to recipient weight. Recipient kidney function was assessed by calculating the estimated glomerular filtration rate (eGFR) using the Chronic Kidney Disease Epidemiology Collaboration formula. Logistic regression models were used to evaluate odds of developing eGFR of <60 mL/min per 1.73m(2) (eGFR<60) at 12 months. RESULTS: Because cortical and total volumes were correlated (R=0.734, P<0.001), we used total kidney volume to evaluate the dose effect. The mean donated volume dose (SD) was 2.13 (0.62) mL/kg. The mean recipient eGFR at 12 months was 63.6 (17.3) mL/min per 1.73 m, and it correlated with volume dose (r=0.341, P<0.001). Compared with the lowest tertile, those in the highest tertile of donor kidney volume to recipient weight had lower odds ratio of developing eGFR of less than 60 mL/min per 1.73 m(2) (odds ratio, 0.23; 95% confidence interval, 0.07-0.81) in a multivariate logistic regression model. Spline regression suggested that a volume dose greater than 2.5 mL/kg was associated with lowest risk of eGFR of less than 60 mL/min per 1.73 m(2) at 12 months. CONCLUSIONS: Donor kidney volume dosing is an important determinant of recipient graft outcomes and may predict recipient kidney function in kidney transplantation.