2-Step-Scores with optional nephropathology for the prediction of adverse outcomes for brain-dead donor kidneys in Eurotransplant.

BACKGROUND AND HYPOTHESIS: The decision for acceptance or discard of the increasingly rare and marginal brain-dead donor kidneys in Eurotransplant (ET) countries has to be made without solid evidence. Thus, we developed and validated flexible clinicopathological scores called 2-Step Scores for the prognosis of delayed graft function (DGF) and one-year death-censored transplant loss (1y-tl) reflecting the current practice of six ET countries including Croatia and Belgium. METHODS: The training set was n=620 for DGF and n=711 for 1y-tl, with validation sets n=158 and n=162. In step 1, stepwise logistic regression models including only clinical predictors were used to estimate the risks. In step 2, risk estimates were updated for statistically relevant intermediate risk percentiles with nephropathology. RESULTS: Step 1 revealed an increased risk of DGF with increased cold ischaemia time, donor and recipient BMI, dialysis vintage, number of HLA-DR mismatches or recipient CMV IgG positivity. On the training and validation set, c-statistics were 0.672 and 0.704, respectively. At a range between 18% and 36%, accuracy of DGF-prognostication improved with nephropathology including number of glomeruli and Banff cv (updated overall c statistics of 0.696 and 0.701, respectively).Risk of 1y-tl increased in recipients with cold ischaemia time, sum of HLA-A. -B, -DR mismatches and donor age. On training and validation sets, c-statistics were 0.700 and 0.769, respectively. Accuracy of 1y-tl prediction improved (c-statistics = 0.706 and 0.765) with Banff ct. Overall, calibration was good on the training, but moderate on the validation set; discrimination was at least as good as established scores when applied to the validation set. CONCLUSION: Our flexible 2-Step Scores with optional inclusion of time-consuming and often unavailable nephropathology should yield good results for clinical practice in ET, and may be superior to established scores. Our scores are adaptable to donation after cardiac death and perfusion pump use.

A paired-kidney allocation study found superior survival with HLA-DR compatible kidney transplants in the Eurotransplant Senior Program.

The Eurotransplant Senior Program (ESP) has expedited the chance for elderly patients with kidney failure to receive a timely transplant. This current study evaluated survival parameters of kidneys donated after brain death with or without matching for HLA-DR antigens. This cohort study evaluated the period within ESP with paired allocation of 675 kidneys from donors 65 years and older to transplant candidates 65 years and older, the first kidney to 341 patients within the Eurotransplant Senior DR-compatible Program and 334 contralateral kidneys without (ESP) HLA-DR antigen matching. We used Kaplan-Meier estimates and competing risk analysis to assess all cause mortality and kidney graft failure, respectively. The log-rank test and Cox proportional hazards regression were used for comparisons. Within ESP, matching for HLA-DR antigens was associated with a significantly lower five-year risk of mortality (hazard ratio 0.71; 95% confidence interval 0.53-0.95) and significantly lower cause-specific hazards for kidney graft failure and return to dialysis at one year (0.55; 0.35-0.87) and five years (0.73; 0.53-0.99) post-transplant. Allocation based on HLA-DR matching resulted in longer cold ischemia (mean difference 1.00 hours; 95% confidence interval: 0.32-1.68) and kidney offers with a significantly shorter median dialysis vintage of 2.4 versus 4.1 yrs. in ESP without matching. Thus, our allocation based on HLA-DR matching improved five-year patient and kidney allograft survival. Hence, our paired allocation study suggests a superior outcome of HLA-DR matching in the context of old-for-old kidney transplantation.

Feasibility and Potential of Transcriptomic Analysis Using the NanoString nCounter Technology to Aid the Classification of Rejection in Kidney Transplant Biopsies.

BACKGROUND: Transcriptome analysis could be an additional diagnostic parameter in diagnosing kidney transplant (KTx) rejection. Here, we assessed feasibility and potential of NanoString nCounter analysis of KTx biopsies to aid the classification of rejection in clinical practice using both the Banff-Human Organ Transplant (B-HOT) panel and a customized antibody-mediated rejection (AMR)-specific NanoString nCounter Elements (Elements) panel. Additionally, we explored the potential for the classification of KTx rejection building and testing a classifier within our dataset. METHODS: Ninety-six formalin-fixed paraffin-embedded KTx biopsies were retrieved from the archives of the ErasmusMC Rotterdam and the University Hospital Cologne. Biopsies with AMR, borderline or T cell-mediated rejections (BLorTCMR), and no rejection were compared using the B-HOT and Elements panels. RESULTS: High correlation between gene expression levels was found when comparing the 2 chemistries pairwise (r = 0.76-0.88). Differential gene expression (false discovery rate; P < 0.05) was identified in biopsies diagnosed with AMR (B-HOT: 294; Elements: 76) and BLorTCMR (B-HOT: 353; Elements: 57) compared with no rejection. Using the most predictive genes from the B-HOT analysis and the Element analysis, 2 least absolute shrinkage and selection operators-based regression models to classify biopsies as AMR versus no AMR (BLorTCMR or no rejection) were developed achieving an receiver-operating-characteristic curve of 0.994 and 0.894, sensitivity of 0.821 and 0.480, and specificity of 1.00 and 0.979, respectively, during cross-validation. CONCLUSIONS: Transcriptomic analysis is feasible on KTx biopsies previously used for diagnostic purposes. The B-HOT panel has the potential to differentiate AMR from BLorTCMR or no rejection and could prove valuable in aiding kidney transplant rejection classification.

Noninvasive Diagnosis of Acute Rejection in Renal Transplant Patients Using Mass Spectrometric Analysis of Urine Samples: A Multicenter Diagnostic Phase III Trial.

Timely recognition and treatment of acute kidney graft rejection is important to prevent premature graft failure. A predefined urinary marker set for acute T cell-mediated rejection (TCMR) containing 14 peptides was tested for this purpose in a multicenter in-place validation study. Methods: Three hundred twenty-nine prospectively collected and 306 archived urine samples from 11 transplant centers in Germany, France, and Belgium were examined. Samples were taken immediately before a biopsy, performed for graft dysfunction within the first transplant year. Primary outcomes were sensitivity and specificity of the marker set for the diagnosis of biopsy-proven acute TCMR, with prespecified thresholds of 83% for sensitivity and 70% for specificity. Results: Eighty-two patients (13%) had acute TCMR grade I-III. In relation to the biopsy diagnosis of TCMR, the sensitivity of the urine test was 0.66 (95% confidence interval, 0.56-0.76) and the specificity 0.47 (95% confidence interval, 0.43-0.51), with an area under the curve (AUC) of 0.60. The different TCMR grades I-III were not reflected by the marker set, and borderline TCMR was not specifically detected. Secondary independent masked assessment of biopsies consented by 2 pathologists revealed an interobserver kappa value of 0.49 for diagnosing TCMR, compared with the local center's diagnosis. Using this consensus diagnosis, the AUC of the urine test was 0.63 (sensitivity 0.73, specificity 0.45). Post hoc optimization of the marker set improved the diagnostic performance in the study cohort (AUC 0.67) and in an independent patient cohort (AUC 0.69). Conclusions: This study illustrates the difficulty of proteomics-based diagnosis of TCMR and highlights the need for rigorous independent in-place validation and optimization of diagnostic biomarkers.

Sirolimus in renal transplant recipients with malignancies in Germany.

BACKGROUND: Renal transplant recipients have an increased cancer risk. The mammalian target of rapamycin inhibitor sirolimus (SRL) has immunosuppressive and antitumour activities but knowledge about its use in recipients with cancer is limited. METHODS: We retrospectively analysed 726 renal allograft recipients converted to SRL from 10 German transplant centres. Patient and graft survival were analysed depending on malignancy status prior to conversion and tumour entity. RESULTS: Malignancy before conversion to SRL was reported in 230 patients, with 137 patients having skin cancers and 101 having solid cancers. Cancer occurred 4.6 ± 9.4 (median 3.0) years after transplantation. Basal cell carcinoma, squamous cell carcinoma and Bowen's disease were the most prevalent skin cancers, while carcinomas of the kidney, colon and breast were the most prevalent solid cancers before conversion. Patients with prior malignancy were older and had better renal function at conversion compared with patients without a history of cancer. After conversion to SRL, cancer incidence rates (IRs) of all tumours were lower compared with rates before conversion. Cancer IRs after conversion were higher in patients with malignancy before conversion compared with those without. Patient survival was worse in patients with solid cancers compared with patients with skin cancers or without malignancies. Biopsy-proven acute rejections in the first year after conversion were less frequent in patients with malignancy compared with those without. Graft survival and renal function in all cancer types were better than in patients converted to SRL without cancers. CONCLUSIONS: Conversion to SRL in patients with a history of cancer is safe regarding renal function and graft survival, while patient survival is largely dependent on tumour entity.

Renal Function and Patient-Reported Outcomes in Stable Kidney Transplant Patients Following Conversion From Twice-Daily Immediate-Release Tacrolimus to Once-Daily Prolonged-Release Tacrolimus: A 12-Month Observational Study in Routine Clinical Practice in Germany (ADAGIO).

INTRODUCTION: This 12-month, noninterventional study on routine clinical practice in Germany evaluated renal function in stable kidney transplant recipients converted from immediate-release tacrolimus (IR-T) to prolonged-release tacrolimus (PR-T). METHODS: Renal function was assessed in 183 patients by estimated glomerular filtration rate using the modification of diet in renal disease-4 formula. Self-reported gastrointestinal health-related quality of life, adherence, satisfaction with PR-T, suspected rejection episodes, and safety were also assessed at conversion and at 3, 6, and 12 months. RESULTS: Conversion from IR-T to PR-T resulted in stable kidney function over 12 months, with a difference in estimated glomerular filtration rate between the first and final visits of 0.1 mL/min/1.73 m2 (95% confidence interval, -1.6, 1.8). Eight patients experienced an acute rejection episode (4.4%). At each assessment, gastrointestinal health-related quality of life was low and adherence was high. Most patients reported that they were very satisfied (69.8%) or satisfied (28.1%) with PR-T at the final visit. Among patients reporting a preference, 78.4% preferred PR-T, 2.2% preferred IR-T, and 19.4% reported no preference. The safety profile of PR-T was consistent with that previously described. CONCLUSION: Conversion of stable kidney transplant recipients from IR-T to PR-T provided stable kidney and graft function over 12 months (Verband Forschender Arzneimittelhersteller--registered study: NIS ADV-02).

Determinants of Successful Use of Sirolimus in Renal Transplant Patients.

BACKGROUND: Sirolimus is an established immunosuppressant in renal transplantation with antineoplastic and antiviral features, but side effects like proteinuria limit its use. The aim of this retrospective multicenter observational study is to define predictors for determining which patients most likely benefit from a sirolimus-based therapy. METHODS: All patients from 10 German centers that were switched to a sirolimus-containing maintenance immunosuppression in 2000 to 2008 after 3 months or later post-transplantation were enrolled (n = 726). Observation times after switching to sirolimus ranged from 4 days to 9 years (median: 24.3 months). With multinomial logistic regression, risk factors for the endpoints terminal graft failure and withdrawal of sirolimus therapy compared to successful therapy were identified. RESULTS: Successful sirolimus therapy was observed in 304 patients. Forty patients died with functioning graft. Therapy failures included graft loss (n = 106) and sirolimus-discontinuation for various reasons (n = 276). Successful sirolimus-use was predicted in 83% and graft failure in 65%, whereas prediction of deliberate sirolimus-discontinuation was poor (48%). Most favorable results for sirolimus-use were observed in patients switched in 2006 to 2008. Using ROC analysis, an estimated glomerular filtration rate (eGFR) below 32 mL/min was shown to be the cut-off in patients withdrawing from therapy as a result of renal reasons, as well as in patients with graft loss. Proteinuria above 151 mg/L was shown to be predictive for patients with graft failure. CONCLUSIONS: eGFR and proteinuria are the major determinants for successful sirolimus-therapy. Our findings help stratifying patients who will benefit most from this therapy and avoid toxicities in patients without potential benefits for this therapy.

Should kidney allografts from old donors be allocated only to old recipients?

In several deceased donor kidney allocation systems, organs from elderly donors are allocated primarily to elderly recipients. The Eurotransplant Senior Program (ESP) was implemented in 1999, and since then, especially in Europe, the use of organs from elderly donors has steadily increased. The proportion of ≥60-year-old donors reported to the Collaborative Transplant Study (CTS) by European centers has doubled, from 21% in 2000-2001 to 42% in 2016-2017. Therefore, in the era of organ shortage it is a matter of debate whether kidney organs from elderly donors should only be allocated to elderly recipients or whether <65-year-old recipients can also benefit from these generally as "marginal" categorized organs. To discuss this issue, a European Consensus Meeting was organized by the CTS on April 12, 2018, in Heidelberg, in which 36 experts participated. Based on available evidence, it was unanimously concluded that kidney organs from 65- to 74-year-old donors can also be allocated to 55- to 64-year-old recipients, especially if these organs are from donors with no history of hypertension, no increased creatinine, no cerebrovascular death, and no other reasons for defining a marginal donor, such as diabetes or cancer.

Repeated kidney re-transplantation-the Eurotransplant experience: a retrospective multicenter outcome analysis.

In Eurotransplant kidney allocation system (ETKAS), candidates can be considered unlimitedly for repeated re-transplantation. Data on outcome and benefit are indeterminate. We performed a retrospective 15-year patient and graft outcome data analysis from 1464 recipients of a third or fourth or higher sequential deceased donor renal transplantation (DDRT) from 42 transplant centers. Repeated re-DDRT recipients were younger (mean 43.0 vs. 50.2 years) compared to first DDRT recipients. They received grafts with more favorable HLA matches (89.0% vs. 84.5%) but thereby no statistically significant improvement of patient and graft outcome was found as comparatively demonstrated in 1st DDRT. In the multivariate modeling accounting for confounding factors, mortality and graft loss after 3rd and ≥4th DDRT (P < 0.001 each) and death with functioning graft (DwFG) after 3rd DDRT (P = 0.001) were higher as compared to 1st DDRT. The incidence of primary nonfunction (PNF) was also significantly higher in re-DDRT (12.7%) than in 1st DDRT (7.1%; P < 0.001). Facing organ shortage, increasing waiting time, and considerable mortality on dialysis, we question the current policy of repeated re-DDRT. The data from this survey propose better HLA matching in first DDRT and second DDRT and careful selection of candidates, especially for ≥4th DDRT.

Everolimus in de novo kidney transplant recipients participating in the Eurotransplant senior program: Results of a prospective randomized multicenter study (SENATOR).

Early conversion to everolimus was assessed in kidney transplant recipients participating in the Eurotransplant Senior Program (ESP), a population in whom data are lacking. The SENATOR multicenter study enrolled 207 kidney transplant recipients undergoing steroid withdrawal at week 2 post-transplant (ClinicalTrials.gov [NCT00956293]). At week 7, patients were randomized (1:2 ratio) to continue the previous calcineurin inhibitor (CNI)-based regimen with mycophenolic acid (MPA) and cyclosporine or switch to a CNI-free regimen with MPA, everolimus (5-10 ng/mL) and basiliximab at weeks 7 and 12, then followed for 18 weeks to month 6 post-transplant. The primary endpoint was estimated GFR (eGFR). At week 7, 77/207 (37.2%) patients were randomized (53 everolimus, 24 control). At month 6, eGFR was comparable: 36.5±10.8ml/min with everolimus versus 42.0±13.0ml/min in the control group (p = 0.784). Discontinuation due to adverse events occurred in 27.8% of everolimus-treated patients and 0.0% of control patients (p = 0005). Efficacy profiles showed no difference. In conclusion, eGFR, safety and efficacy outcomes at month 6 post-transplant showed no difference between groups. The everolimus group experienced a higher rate of discontinuation due to adverse events. However, the high rate of non-randomization is highly relevant, indicating this to be a somewhat unstable patient population regardless of treatment.

Preformed Donor-Specific HLA Antibodies in Living and Deceased Donor Transplantation: A Multicenter Study.

BACKGROUND AND OBJECTIVES: The prognostic value of preformed donor-specific HLA antibodies (DSA), which are only detectable by sensitive methods, remains controversial for kidney transplantation. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: The outcome of 4233 consecutive kidney transplants performed between 2012 and 2015 in 18 German transplant centers was evaluated. Most centers used a stepwise pretransplant antibody screening with bead array tests and differentiation of positive samples by single antigen assays. Using these screening results, DSA against HLA-A, -B, -C, -DRB1 and -DQB1 were determined. Data on clinical outcome and possible covariates were collected retrospectively. RESULTS: Pretransplant DSA were associated with lower overall graft survival, with a hazard ratio of 2.53 for living donation (95% confidence interval [95% CI], 1.49 to 4.29; P<0.001) and 1.59 for deceased donation (95% CI, 1.21 to 2.11; P=0.001). ABO-incompatible transplantation was associated with worse graft survival (hazard ratio, 2.09; 95% CI, 1.33 to 3.27; P=0.001) independent from DSA. There was no difference between DSA against class 1, class 2, or both. Stratification into DSA <3000 medium fluorescence intensity (MFI) and DSA ≥3000 MFI resulted in overlapping survival curves. Therefore, separate analyses were performed for 3-month and long-term graft survival. Although DSA <3000 MFI tended to be associated with both lower 3-month and long-term transplant survival in deceased donation, DSA ≥3000 MFI were only associated with worse long-term transplant survival in deceased donation. In living donation, only strong DSA were associated with reduced graft survival in the first 3 months, but both weak and strong DSA were associated with reduced long-term graft survival. A higher incidence of antibody-mediated rejection within 6 months was only associated with DSA ≥3000 MFI. CONCLUSIONS: Preformed DSA were associated with an increased risk for graft loss in kidney transplantation, which was greater in living than in deceased donation. Even weak DSA <3000 MFI were associated with worse graft survival. This association was stronger in living than deceased donation.

Onset and progression of diabetes in kidney transplant patients receiving everolimus or cyclosporine therapy: an analysis of two randomized, multicenter trials.

BACKGROUND: Conversion from calcineurin inhibitor (CNI) therapy to a mammalian target of rapamycin (mTOR) inhibitor following kidney transplantation may help to preserve graft function. Data are sparse, however, concerning the impact of conversion on posttransplant diabetes mellitus (PTDM) or the progression of pre-existing diabetes. METHODS: PTDM and other diabetes-related parameters were assessed post hoc in two large open-label multicenter trials. Kidney transplant recipients were randomized (i) at month 4.5 to switch to everolimus or remain on a standard cyclosporine (CsA)-based regimen (ZEUS, n = 300), or (ii) at month 3 to switch to everolimus, remain on standard CNI therapy or convert to everolimus with reduced-exposure CsA (HERAKLES, n = 497). RESULTS: There were no significant differences in the incidence of PTDM between treatment groups (log rank p = 0.97 [ZEUS], p = 0.90 [HERAKLES]). The mean change in random blood glucose from randomization to month 12 was also similar between treatment groups in both trials for patients with or without PTDM, and with or without pre-existing diabetes. The change in eGFR from randomization to month 12 showed a benefit for everolimus versus comparator groups in all subpopulations, but only reached significance in larger subgroups (no PTDM or no pre-existing diabetes). CONCLUSIONS: Within the restrictions of this post hoc analysis, including non-standardized diagnostic criteria and limited glycemia laboratory parameters, these data do not indicate any difference in the incidence or severity of PTDM with early conversion from a CsA-based regimen to everolimus, or in the progression of pre-existing diabetes. TRIAL REGISTRATION: clinicaltrials.gov , NCT00154310 (registered September 2005) and NCT00514514 (registered August 2007); EudraCT ( 2006-007021-32 and 2004-004346-40 ).

Histological findings to five years after early conversion of kidney transplant patients from cyclosporine to everolimus: an analysis from the randomized ZEUS study.

BACKGROUND: Conversion from calcineurin inhibitor (CNI) therapy to everolimus within 6 months after kidney transplantation improves long-term graft function but can increase the risk of mild biopsy-proven acute cellular rejection (BPAR). We performed a post-hoc analysis of histological data from a randomized trial in order to further analyze histologic information obtained from indication and protocol biopsies up to 5 years after transplantation. METHODS: Biopsy samples obtained up to 5 years post-transplant were analyzed from the randomized ZEUS study, in which kidney transplant patients were randomized at month 4.5 to switch to everolimus (n = 154) or remain on cyclosporine (CsA)-based immunosuppression (n = 146). All patients received mycophenolate and steroids. RESULTS: At least one investigator-initiated biopsy was undertaken in 53 patients in each group between randomization and year 5, with a mean (SD) of 2.6 (1.7) and 2.2 (1.4) biopsies per patient in the everolimus and CsA groups, respectively. In the everolimus and CsA groups, investigator-initiated biopsies showed (i) BPAR in 12.3 and 7.5% (p = 0.182) of patients, respectively, with episodes graded mild in 22/24 and 18/20 cases (ii) CsA toxicity lesions in 4.5 and 10.3% of patients (p = 0.076) (iii) antibody-mediated rejection in 0.6 and 2.7% of patients (p = 0.204), respectively. CONCLUSIONS: This analysis of histological findings in the ZEUS study to 5 years after kidney transplantation shows no increase in antibody-mediated rejection under everolimus-based therapy with a lower rate of CNI-related toxicity compared to a conventional CsA-based regimen, and confirms the preponderance of mild BPAR seen in the main study after the early switch to CsA-free everolimus therapy. TRIAL REGISTRATION: ClinicalTrials.gov NCT00154310 . Date of registration: September 12, 2005.

Five-year outcomes in kidney transplant patients randomized to everolimus with cyclosporine withdrawal or low-exposure cyclosporine versus standard therapy.

HERAKLES was a 1-year randomized, multicenter trial. Patients were randomized at 3 months after kidney transplantation to remain on cyclosporine-based therapy, switch to everolimus without a calcineurin inhibitor (CNI), or switch to everolimus with low-exposure cyclosporine. Overall, 417 of 497 (83.9%) patients from the core study entered a 4-year extension study. The randomized regimen was continued to year 5 in 75.9%, 41.9% and 24.6% of patients in the standard-CNI, CNI-free and low-CNI groups, respectively. Adjusted estimated GFR at year 5 was significantly higher in the CNI-free group versus standard CNI (difference 7.2 mL/min/1.73 m2 , P < .001) or low CNI (difference 7.6 mL/min/1.73 m2 , P < .001). For patients who continued randomized therapy for 5 years, differences were 14.4 mL/min/1.73 m2  and 10.1 mL/min/1.73 m2 , respectively. Biopsy-proven acute rejection occurred during the 4-year extension study in 7.6%, 8.6%, and 9.0% of patients in the standard-CNI, CNI-free and low-CNI groups, respectively (P = .927). In conclusion, conversion to a CNI-free everolimus regimen 3 months after kidney transplantation improved long-term graft function, particularly in patients who continued the CNI-free regimen. Low CNI with everolimus did not improve renal function. Efficacy was comparable between groups but frequent immunosuppression changes should be taken into account.

Everolimus with cyclosporine withdrawal or low-exposure cyclosporine in kidney transplantation from Month 3: a multicentre, randomized trial.

BACKGROUND.: Randomized trials have shown that early adoption of everolimus-based immunosuppressive regimens without a calcineurin inhibitor (CNI) improves long-term kidney graft function, but the optimal strategy for CNI minimization remains uncertain. METHODS.: In a prospective, randomized, multicentre, 12-month trial, 499 de novo kidney transplant patients were randomized at Month 3 to (i) remain on standard CNI (cyclosporine) therapy with mycophenolic acid, (ii) convert to everolimus with mycophenolic acid or (iii) start everolimus with reduced CNI and no mycophenolic acid (clinical trials registry: ClinicalTrials.gov-NCT00514514). RESULTS.: The primary endpoint, change in estimated glomerular filtration rate (eGFR) (Nankivell) from randomization to Month 12, was significantly greater in the CNI-free arm versus standard CNI therapy: mean difference 5.6 mL/min/1.73 m 2 [95% confidence interval (CI) 2.8-8.3 mL/min/1.73 m 2 , P < 0.001]. The improvement in eGFR in the CNI-free arm was also higher than in the low-CNI group (mean difference 5.5 mL/min/1.73 m 2 , 95% CI 2.8-8.2 mL/min/1.73 m 2 , P < 0.001), while results were similar in the low-CNI and standard CNI arms. The post-randomization incidence of biopsy-proven acute rejection was 11.7%, 8.1% and 7.9% in the CNI-free, low-CNI and standard CNI groups, respectively (CNI-free versus standard CNI, P = 0.27; low-CNI versus standard CNI, P = 1.00). Adverse events led to study drug discontinuation in 28.7%, 15.5% and 15.2% of CNI-free, low-CNI and standard CNI patients, respectively. CONCLUSIONS.: Everolimus initiation with CNI withdrawal at Month 3 after kidney transplantation achieves a significant improvement in renal function at 12 months, with a similar rate of acute rejection.

Rescue allocation and recipient oriented extended allocation in kidney transplantation-influence of the EUROTRANSPLANT allocation system on recipient selection and graft survival for initially nonaccepted organs.

Nonaccepted kidneys grafts enter the rescue allocation (RA) process to avoid discards. In December 2013, recipient oriented extended allocation (REAL) was introduced to improve transparency. The aim of this study was to evaluate the influence of REAL on recipients' selection and graft function compared to the formerly existing RA as well as to identify factors that influence graft outcome. Therefore, a multicenter study of 10 transplant centers in the same region in Germany was performed. All transplantations after RA or REAL from December 1, 2012, until December 31, 2014, with a follow-up time until December 31, 2015 were analyzed. 113 of 941 kidney transplantations were performed after RA or REAL (12%). With REAL, the number of refusals before transplantation had increased (12 ± 7.1 vs. 8.6 ± 8.6, P = 0.036), and cold ischemia time has decreased (13.6 ± 3.6 vs. 17.2 ± 4.8 h, P = 0.019). Recipients after REAL needed significantly more allocation points compared to RA to receive a kidney. One-year graft survival was comparable. If kidneys from the same donor were transplanted to two recipients at one center, the greater the difference in recipient age, the greater the difference in serum creatinine after 12 months (-0.019 mg/dl per year, P = 0.011) was, that is older recipients showed lower creatinine. REAL influences selection of the recipients compared to the former RA era for successful organ receipt. Graft function is comparable and seems to be influenced by recipient age.

Pharmacokinetics and Clinical Outcomes of Generic Tacrolimus (Hexal) Versus Branded Tacrolimus in De Novo Kidney Transplant Patients: A Multicenter, Randomized Trial.

BACKGROUND: Scrupulous comparison of the pharmacokinetic and clinical characteristics of generic tacrolimus formulations versus the reference drug (Prograf) is essential. The pharmacokinetics of the Tacrolimus Hexal (TacHexal) formulation is similar to Prograf in stable renal transplant patients, but data in de novo patients are lacking. METHODS: De novo kidney transplant patients were randomized to generic tacrolimus (TacHexal) or Prograf in a 6-month open-label study. RESULTS: The primary end point, the dose-normalized area under the curve0-12h at month 1 posttransplant, was similar with TacHexal or Prograf; back-transformed geometric means of adjusted log-transformed values (analysis of variance) were 18.99 ng·h·L (TacHexal) and 20.48 ng·h·L (Prograf) (ratio, 1.08; 90% confidence interval, 0.84-1.38; P = 0.605). The dose-normalized peak concentration geometric means at month 1 was also comparable between treatments (ratio, 1.16; 90% confidence interval, 0.88-1.54; P = 0.377). There were no relevant differences in other pharmacokinetic parameters at month 1 or in area under the curve0-4h and trough concentration when measured at months 3 and 6. The adjusted change in mean estimated glomerular filtration rate from baseline to month 6 (Nankivell) was noninferior for TacHexal versus Prograf using observed values (47.7 vs 38.6 mL/min per 1.73 m, P < 0.001) and was superior based on observed values (P = 0.044) but not using last observation-carried forward method. Rates of biopsy-proven acute rejection (5.7% vs 7.9%), adverse events, and serious adverse events were similar with TacHexal or Prograf. CONCLUSION: Tacrolimus pharmacokinetics is similar with TacHexal and Prograf early after kidney transplantation. Efficacy and safety in this limited data set were comparable, with at least equivalent graft function under TacHexal.

Unacceptable human leucocyte antigens for organ offers in the era of organ shortage: influence on waiting time before kidney transplantation.

BACKGROUND: The assignment of human leucocyte antigens (HLAs) against which antibodies are detected as unacceptable antigens (UAGs) avoids allocation of HLA- incompatible allografts. There is uncertainty as to what extent UAGs decrease the probability of receiving a kidney offer. METHODS: Kidney transplantations in 3264 patients on the waiting lists of six German transplant centres were evaluated for a period of at least 2 years. The proportion of excluded offers due to UAGs was calculated as virtual panel-reactive antibodies (vPRAs). RESULTS: In the common Eurotransplant Kidney Allocation Scheme, the transplant probability was unaffected by vPRAs in exploratory univariate analyses. In the multivariable model, a 1% increase in vPRA values was outweighed by an additional waiting time of 2.5 weeks. The model was confirmed using an external validation cohort of 1521 patients from seven centres. If only patients with standard risk were considered (e.g. no simultaneous transplantation of other organs), only 1.3 weeks additional waiting time was needed. In the Eurotransplant Senior Program, patients with vPRA values >50% had a strongly reduced transplant probability in the unadjusted analyses. In the multivariable model, a 1% increase in vPRA values was outweighed by an additional waiting time of 5 weeks. CONCLUSIONS: This study demonstrates that the assignment of UAGs decreases the transplant probability in both main Eurotransplant allocation programs because of insufficient compensatory mechanisms. At present, for immunized patients, a prolonged waiting time has to be weighed against the increased immunologic risk due to donor-specific antibodies not assigned as UAGs.

Urinary Calprotectin Differentiates Between Prerenal and Intrinsic Acute Renal Allograft Failure.

BACKGROUND: Urinary calprotectin has recently been identified as a promising biomarker for the differentiation between prerenal and intrinsic acute kidney injury (AKI) in the nontransplant population. The present study investigates whether calprotectin is able to differentiate between these 2 entities in transplant recipients as well. METHODS: Urinary calprotectin was assessed by enzyme-linked immunosorbent assay in 328 subjects including 125 cases of intrinsic acute allograft failure, 27 prerenal graft failures, 118 patients with stable graft function, and 58 healthy controls. Acute graft failure was defined as AKI stages 1 to 3 (Acute Kidney Injury Network criteria), exclusion criteria were obstructive uropathy, urothelial carcinoma, and metastatic cancer. The clinical differentiation of prerenal and intrinsic graft failure was performed either by biopsy or by a clinical algorithm including response to fluid repletion, history, physical examination, and urine dipstick examination. RESULTS: Reasons for intrinsic graft failure comprised rejection, acute tubular necrosis, urinary tract infection/pyelonephritis, viral nephritis, and interstitial nephritis. Calprotectin concentrations of patients with stable graft function (50.4 ng/mL) were comparable to healthy controls (54.8 ng/mL, P = 0.70) and prerenal graft failure (53.8 ng/mL, P = 0.62). Median urinary calprotectin was 36 times higher in intrinsic AKI (1955 ng/mL) than in prerenal AKI (P < 0.001). Receiver-operating characteristic curve analysis revealed a high accuracy of calprotectin (area under the curve, 0.94) in the differentiation of intrinsic versus prerenal AKI. A cutoff level of 134.5 ng/mL provided a sensitivity of 90.4% and a specificity of 74.1%. Immunohistochemical stainings for calprotectin in renal allograft biopsy specimens confirmed the serological results. CONCLUSIONS: Urinary calprotectin is a promising biomarker for the differentiation of prerenal and intrinsic acute renal allograft failure.