How Delayed Graft Function Impacts Exposure to Mycophenolic Acid in Patients After Renal Transplantation

Introduction: Mycophenolic acid (MPA) plasma concentrations are highly variable on standard-dose mycophenolate mofetil therapy. At creatinine clearances below 25 mL/min, MPA clearance increases as a result of a higher nonprotein-bound fraction. Patients with delayed graft function (DGF) after renal transplantation are exposed to low total MPA concentrations, when risk of rejection is highest. This study investigated the influence of DGF on MPA exposure and on clinical outcome.Methods: Adult renal transplantation patients treated with mycophenolate mofetil, corticosteroids, and either microemulsified cyclosporine (n = 459) or tacrolimus (n = 371) participated in a randomized controlled trial (the Fixed-Dose Concentration-Controlled [FDCC] Study). Abbreviated MPA areas under the curve (AUCs) were obtained on Day 3, Day 10, Week 4, and Month 3, to calculate MPA AUC((0-12)). Free MPA AUC values were available for a subgroup of patients (n = 269).Results: the overall incidence of DGF was 187 of 830 (23%) and did not differ between cyclosporine-treated (24%) and tacrolimus-(21%) treated patients. the incidence of biopsy-proven acute rejection at 12 months was significantly higher in patients with DGF (13.8% versus 21.4%). Patients with DGF had significantly lower dose-corrected MPA AUC on Day 3 and Day 10. Free MPA fraction and dose-corrected free MPA AUC were significantly higher in patients with DGF, from Day 3 until Month 3. the total number of patients with at least one opportunistic infection was significantly higher in patients with DGF (33.2%) compared with patients without DGF (25.8%) (P = 0.048). Patients with DGF developing opportunistic infections did not have higher total MPA AUC nor higher free MPA AUC compared with those without opportunistic infections.Conclusion: Patients with DGF have significantly lower dose-corrected MPA AUC in the first month after renal transplantation, presumably as a result of enhanced MPA clearance on account of the elevated MPA free fraction. Because patients with DGF have a higher rate of acute rejection and lower MPA exposure, higher dosing of mycophenolate mofetil in such patients may improve outcome. However, the already increased incidence of opportunistic infections in patients with DGF is a concern.F. Hoffmann-La Roche Ltd, Basel, SwitzerlandErasmus MC, Dept Hosp Pharm, Clin Pharmacol Unit, NL-3000 CA Rotterdam, NetherlandsErasmus MC, Dept Internal Med, NL-3000 CA Rotterdam, NetherlandsUniversidade Federal de São Paulo, Hosp Rim & Hipertensao, Dept Nephrol, São Paulo, BrazilLeiden Univ, Med Ctr, Dept Nephrol, Leiden, NetherlandsCharite, Dept Nephrol, D-13353 Berlin, GermanyLeuven Univ, Dept Nephrol & Renal Transplantat, Louvain, BelgiumMamelok Consulting, Palo Alto, CA USAUniv Gottingen, Klin Chem Abt, D-3400 Gottingen, GermanyUniversidade Federal de São Paulo, Hosp Rim & Hipertensao, Dept Nephrol, São Paulo, BrazilWeb of Scienc

INCIDENCE AND OUTCOME OF BK INFECTION IN A RANDOMIZED CONTROLLED MULTICENTER STUDY WITH RENAL TRANSPLANT PATIENTS RECEIVING DUO-THERAPY

Nephrolog

Minimization of Maintenance Immunosuppression Early After Renal Transplantation:An Interim Analysis

Introduction. Chronic allograft nephropathy is the main cause of long-term renal transplant failure. Chronic use of calcineurin inhibitors contributes to its pathogenesis. Here, we report on a multicenter randomized trial to study the effects of withdrawal of cyclosporine A (CsA) from a triple immunosuppressive regimen containing CsA, prednisolone (P), and mycophenolate sodium (MPS) early after transplantation. Methods. Patients continued on P/CsA, P/MPS, or P and everolimus (EVL). Before withdrawal, a transplant biopsy was performed ensuring no subclinical rejection was present. Drug levels were closely monitored. The primary outcome was interstitial graft fibrosis and hyalinosis. Secondary outcome was among others graft rejection. Results. According to trial regulations, an interim analysis was performed after enrollment of half of the intended number of patients (n = 113). Mean follow-up was 14 5 months from transplantation and 8 +/- 5 months from conversion. After conversion, acute rejection percentages were 3% in the P/CsA group, 22% in the P/MPS group, and 0% in the P/EVL group (P Conclusions. We conclude that switching immunosuppressive therapy from P/CsA/MPS to therapy with P/CsA or P/EVL at 6 months after renal transplantation is effective in preventing rejection. Double therapy with P/MPS after withdrawal of P/CsA resulted in an increase in severe acute rejection episodes. These results were the immediate reason to halt the P/MPS arm. Serum creatinine values at the latest follow-up (8 +/- 5 months after conversion and 14 +/- 5 months after transplantation) in the P/EVL group were lower than in the P/CsA group

A combined microRNA and chemokine profile in urine to identify rejection after kidney transplantation

Background. There is an unmet need for noninvasive tools for diagnosis of rejection after kidney transplantation. The aim of this study was to determine the discriminative value of a combined cellular and molecular biomarker platform in urine for the detection of rejection. Methods. First, microRNA (miR) molecules were screened in transplant biopsies and urine sediments of patients with acute rejection and patients without rejection and stable graft function. Second, the expression of 15 selected miRs was quantified in an independent set of 115 urine sediments of patients with rejection and 55 urine sediments of patients without histological signs of rejection on protocol biopsy. Additionally, CXCL-9 and CXCL-10 protein levels were quantified in the urine supernatant. Results. Levels of miR-155-5p (5.7-fold), miR-126-3p (4.2-fold), miR-21-5p (3.7-fold), miR-25-3p (2.5-fold), and miR-615-3p (0.4-fold) were significantly different between rejection and no-rejection urine sediments. CXCL-9 and CXCL-10 levels were significantly elevated in urine from recipients with rejection. In a multivariable model (sensitivity: 89.1%, specificity: 75.6%, area under the curve: 0.94, P < 0.001), miR-155-5p, miR-615-3p, and CXCL-9 levels were independent predictors of rejection. Stratified 10-fold cross validation of the model resulted in an area under the curve of 0.92. Conclusions. A combined urinary microRNA and chemokine profile discriminates kidney transplant rejection from stable graft conditions

Complement Factor C4d Is a Common Denominator in Thrombotic Microangiopathy

Complement activation has a major role in thrombotic microangiopathy (TMA), a disorder that can occur in a variety of clinical conditions. Promising results of recent trials with terminal complement-inhibiting drugs call for biomarkers identifying patients who might benefit from this treatment. The primary aim of this study was to determine the prevalence and localization of complement factor C4d in kidneys of patients with TMA. The secondary aims were to determine which complement pathways lead to C4d deposition and to determine whether complement activation results in deposition of the terminal complement complex. We examined 42 renal sections with histologically confirmed TMA obtained from a heterogeneous patient group. Deposits of C4d, mannose-binding lectin, C1q, IgM, and C5b-9 were scored in the glomeruli, peritubular capillaries, and arterioles. Notably, C4d deposits were present in 88.1% of TMA cases, and the various clinical conditions had distinct staining patterns within the various compartments of the renal vasculature. Classical pathway activation was observed in 90.5% of TMA cases. C5b-9 deposits were present in 78.6% of TMA cases and in 39.6% of controls (n=53), but the staining pattern differed between cases and controls. In conclusion, C4d is a common finding in TMA, regardless of the underlying clinical condition. Moreover, C5b-9 was present in >75% of the TMA samples, suggesting that terminal complement inhibitors may have a beneficial effect in these patients. C4d and C5b-9 should be investigated as possible diagnostic biomarkers in the clinical work-up of patients suspected of having complement-mediated TMA

Long-term cardiovascular outcome of renal transplant recipients after early conversion to everolimus compared to calcineurin inhibition: results from the randomized controlled MECANO trial

Long-term data on cardiovascular (CV) outcome of renal transplant recipients (RTR) on mTOR-i (mammalian Target Of Rapamycin-inhibitors) are scarce. In a sub-study of the MECANO trial we investigated changes in intima media thickness (IMT), CV risk profile, Major Adverse CV Events (MACE) and survival in RTR on a mTORi versus CNI based regimen. Patients (enrolled 361) were treated with (basiliximab) and triple IS (CsA-Cyclosporine A-(C), MPS(M), prednisolone(P)). At M6 patients were randomized (n=224) to the CsA group (C, P, N=89), MPS group (M, P, N=39) EVL group (Everolimus, P, N=96). At week 2, M6 and M 24, IMT measurements of the Common Carotid Artery were performed. Cardiovascular risk factors were assessed at baseline, 6 and 24 months of follow-up. Seven years survival and MACE -free survival probability were calculated by the Cardiovascular Risk Calculator for RTR. After seven years of follow-up incidence of cardiovascular events and patient survival were assessed. Mean IMT at baseline, (N=192), was 0.64±0.14 mm. At M6 (N=158), 0.66±0.15, M24 IMT was 0.68±0.15 (N=95). CONCLUSION: No significant differences between groups concerning IMT, true CV events and mortality, CV risk profile, predicted MACE / Mortality were found between mTORi and CNI-based regimen after 7 years of follow-up. This article is protected by copyright. All rights reserved

Molecular comparison of calcineurin inhibitor-induced fibrogenic responses in protocol renal transplant biopsies

The calcineurin inhibitor cyclosporine (CsA) induces a fibrogenic response that may lead to scarring of the renal allograft. This study investigated whether tacrolimus, a novel calcineurin inhibitor, exerts fibrogenic effects to a similar extent. Sixty patients were enrolled in a randomized study: 29 received CsA, and 31 received tacrolimus. Patients were subjected to tailored exposure-controlled calcineurin inhibitor regimens. Protocol biopsies were obtained at the time of transplantation and 6 and 12 mo after transplantation. Cortical TGF-beta and collagens alpha1(I) and alpha1(III) mRNA steady-state levels were determined with real-time PCR. The extent of protein deposition of TGF-beta, alpha-smooth muscle actin, and interstitial collagens in the renal cortex was quantified with computer-assisted image analysis. The extent of interstitial collagen deposition measured with Sirius red and the accumulation of alpha-smooth muscle actin and TGF-beta protein after 6 and 12 mo were similar for both immunosuppressive regimens. mRNA levels of TGF-beta and collagens alpha1(I) and alpha1(III) were not significantly different in the treatment groups either. It is concluded that the fibrogenic response in renal allografts is similar in patients who receive CsA-based regimens and patients who receive tacrolimus-based regimen

Cardiovascular Risk Following Conversion to Belatacept From a Calcineurin Inhibitor in Kidney Transplant Recipients: A Randomized Clinical TrialPlain-Language Summary

Rationale &amp; Objective: In kidney transplant recipients (KTRs), a belatacept-based immunosuppressive regimen is associated with beneficial effects on cardiovascular (CV) risk factors compared with calcineurin inhibitor (CNI)–based regimens. Our objective was to compare the calculated CV risk between belatacept and CNI (predominantly tacrolimus) treatments using a validated model developed for KTRs. Study Design: Prospective, randomized, open-label, parallel-group, investigator-initiated, international multicenter trial. Setting &amp; Participants: KTRs aged 18-80 years with a stable graft function (estimated glomerular filtration rate > 20 mL/min/1.73 m2), 3-60 months after transplantation, treated with tacrolimus or cyclosporine A, were eligible for inclusion. Intervention: Continuation with a CNI-based regimen or switch to belatacept for 12 months. Outcomes: Comparison of the change in the estimated 7-year risk of major adverse CV events and all-cause mortality, changes in traditional markers of CV health, as well as measures of arterial stiffness. Results: Among the 105 KTRs randomized, we found no differences between the treatment groups in the predicted risk for major adverse CV events or mortality. Diastolic blood pressure, measured both centrally by using a SphygmoCor device and peripherally, was lower after the belatacept treatment than after the CNI treatment. The mean changes in traditional cardiovascular (CV) risk factors, including kidney transplant function, were otherwise similar in both the treatment groups. The belatacept group had 4 acute rejection episodes; 2 were severe rejections, of which 1 led to graft loss. Limitations: The heterogeneous baseline estimated glomerular filtration rate and time from transplantation to trial enrollment in the participants. A limited study duration of 1 year. Conclusions: We found no effects on the calculated CV risk by switching to the belatacept treatment. Participants in the belatacept group had not only lower central and peripheral diastolic blood pressure but also a higher rejection rate. Funding: The trial has received a financial grant from Bristol-Myers Squibb. Trial Registration: EudraCT no. 2013-001178-20