Expanded Criteria Donor Kidneys Research Articles

#1836 Post-transplant evolution of kidney grafts from expanded criteria donors with diabetes

Abstract Background and Aims The increase in the number of potential kidney transplant (KT) recipients has led to efforts to increase the donor pool, including organs from expanded criteria donors (ECD) with diabetes mellitus (DM). However, doubts persist about their viability, especially with DM donors. Our aim is to analyze the post-transplant evolution of KT patients who have received kidney grafts from ECD with or without DM. Method Retrospective observational study of KT who received ECD kidney graft in our center between January 2014 and November 2023. We divided KT patients into two groups based on donor DM; ECD with DM and ECD without DM. We analyzed baseline characteristics and post-KT evolution. Univariate and multivariate statistical analysis was performed using Cox regression (SPSS Statistics 29.0). Results During the study period, 161 patients received grafts from ECD at our center. Pre-implant biopsies were performed on all grafts, with 15 discarded due to high histological score. Of these, 13 (86%) were diabetic donors (p < 0.001). The mean age of donors was 66 years, and that of recipients was 61. Forty-three (26%) KT recipients had a diabetic donor. Clinical characteristics of patients are reflected in Table 1. Conclusion Donors with DM showed adequate survival in our experience, similar to that of other ECD. This may be due to a more stringent pre-transplant clinical selection or pre-KT histological assessment. The development of new techniques is necessary to more precisely asses the viability of these grafts pre-KT, allowing for an increased utilization.

Predictive value of donor kidney quality assessment and risk quantification scores on 5-year outcomes of deceased donor kidney transplantation.

Due to the excess demand for deceased donor kidneys, risk quantification scores were developed to help with kidney allocation. The kidney donor risk index (KDRI) is used in the US kidney allocation system. We currently use expanded criteria (UNOS) and Remuzzi scoring for allocation of deceased donor kidneys and the utility of KDRI in our cohort is unknown. We aim to evaluate the association of KDRI with relation to 5year graft and patient survival. Retrospective cohort study of 225 adults who received a deceased donor kidney transplant between 1 Nov 2005 and 30 June 2014. Patients were followed up for 5years or until graft-loss or death. Implant biopsies of donor kidneys were done and the Remuzzi score was calculated. The median age was 48 (IQR 42, 52.5) years and 50.7% were male. KDRI-USA, KDRI-THAI, and KDRI-AUST were found to have no correlation with 5year graft survival. Donor characteristics which define an expanded criteria donor kidney, not associated with 5year graft survival are age (p = 0.58), terminal creatinine (p = 0.71) and history of hypertension (p = 0.35). Donor cerebrovascular accident (CVA) as a cause of death (p = 0.02) and Remuzzi score were associated with graft survival at 5years, with 75.8% with Remuzzi score ≤ 3 vs 24.2% with Remuzzi score of > 3 achieving 5year graft survival (p = 0.001). The association of KDRI with graft and patient survival was not demonstrated in our cohort. Histological assessment of the transplant kidney remains the best method of predicting long-term survival during donor selection.

Impact of Donation After Circulatory Death on Outcomes of Expanded Criteria Donor Kidney Transplants

Expanded criteria donor (ECD) kidneys experience suboptimal outcomes compared with standard criteria donor kidneys. To examine the additional impact of deceased organ category, donation after circulatory death (DCD), and neurologic determination of death (NDD) on ECD outcomes, we examined 1- and 3-year patient and graft survival in all ECD kidney recipients in our institution between January 2008 and December 2017. Of 166 ECD recipients, 49 (29.5%) were DCD and 117 (70.5%) were NDD. Delayed graft function was higher in the DCD/ECD group 61.2 % vs 32.0 % among NDD/ECD recipients. Graft loss was significantly increased among DCD/ECD (hazard ratio for graft loss 4.81 [95% CI1.78-13.01], P = .002 at 1 year and 2.03 [95% CI 1.03-4.0], P = .042 at 3 years). Death-censored graft loss was higher among DCD/ECD (hazard ratio was 10.12 [95% CI, 2.14, 47.92], P = .004 at 1 year and 2.83 [95% CI, 1.24, 6.46], P = .014 at 3 years). There was no statistically significant difference in all-cause mortality. Our study demonstrated that DCD/ECD kidneys have lower graft survival compared with NDD/ECD kidneys. Time on dialysis, waiting time, and panel reactive antibody should be taken into account when offering these organs to patients.

All Expanded Criteria Donor Kidneys are Equal But are Some More Equal Than Others? A Population-Cohort Analysis of UK Transplant Registry Data.

Survival outcomes for kidney transplant candidates based on expanded criteria donor (ECD) kidney type is unknown. A retrospective cohort study was undertaken of prospectively collected registry data of all waitlisted kidney failure patients receiving dialysis in the United Kingdom. All patients listed for their first kidney-alone transplant between 2000-2019 were included. Treatment types included; living donor; standard criteria donor (SCD); ECD60 (deceased donor aged ≥60years); ECD50-59 (deceased donor aged 50-59years with two from the following three; hypertension; raised creatinine and/or death from stroke) or remains on dialysis. The primary outcome was all-cause mortality, with time-to-death from listing analyzed using time-dependent non-proportional Cox regression models. The study cohort comprised 47,917 waitlisted kidney failure patients, of whom 34,558 (72.1%) received kidney transplantation. ECD kidneys (n = 7,356) were stratified as ECD60 (n = 7,009) or ECD50-59 (n = 347). Compared to SCD, both ECD60 (Hazard Ratio 1.126, 95% CI 1.093-1.161) and ECD50-59 (Hazard Ratio 1.228, 95% CI 1.113-1.356) kidney recipients have higher all-cause mortality. However, compared to dialysis, both ECD60 (Hazard Ratio 0.194, 95% CI 0.187-0.201) and ECD50-59 (Hazard Ratio 0.218, 95% CI 0.197-0.241) kidney recipients have lower all-cause mortality. ECD kidneys, regardless of definition, provide equivalent and superior survival benefits in comparison to remaining waitlisted.

Survival after kidney transplantation compared with ongoing dialysis for people over 70 years of age: A matched-pair analysis

Kidney transplantation offers improved survival and quality of life compared to dialysis for most recipients; however, benefits for elderly patients (>70 years) remain uncertain. Using the Australia and New Zealand Dialysis and Transplant Registry (2009-2019), elderly transplant recipients were matched to a waitlisted dialysis patient by age, cause of end-stage kidney disease, and dialysis duration (paired controls). We censored dialysis patients at the time of transplant. Survival was compared using stratified Cox regression. Elderly transplant recipients (KTRs) (n = 465) were matched to waitlisted pairs. Transplant group mortality initially exceeded dialysis due to excess infection-related deaths (1.9 transplant versus 0.3 dialysis/100 patient-years, P = .03). Beyond month 9, a progressive survival benefit in favor of transplantation was apparent. Over a median follow-up of 1.7 years, mortality was 38% lower for KTRs (95% confidence interval 0.41-0.94, P = .02), and 5-year survival was 80% KTRs vs 53% dialysis (P < .001). Recipients of living and standard criteria donor kidneys acquired immediate survival advantage compared with dialysis, while recipients of expanded criteria donor's kidneys experienced elevated risk of death for the first 17 months. Compared with remaining on dialysis, elderly KTRs incur an increased risk of early posttransplant mortality but thereafter may anticipate progressively superior survival rates.

Midterm Outcomes of Kidney Transplantation from Expanded Criteria Donors After Circulatory Death: A Single-Center Retrospective Cohort Study.

Kidney transplant is the optimal treatment for end-stage renal disease; however, due to the imbalance between demand and supply, several strategies have been implemented to increase the donor pool. To increase the number of donors, expanded criteria donors after circulatory death have been explored as an acceptable graft source. In this study, we compared graft survival, estimated glomerular filtration rate at 3 and 5 years, and the incidence of delayed graft function between standard and expanded criteria donors after brain death and between standard and expanded criteria donors after circulatory death. A prospective cohort study was conducted between January 1, 2015, and December 31, 2019, at Reina Sofia University Hospital. Variables related to the donor, recipient, and transplant procedure were analyzed, and univariate and multivariate logistic and Cox regression analyses were performed. Our study included 308 deceased donor kidneys. The kidneys from standard criteria brain dead donors had higher estimated glomerular filtration rate than the other groups (P < .03).However, no significant differences in estimated glomerular filtration rate were observed among the suboptimal groups (expanded criteria and standard criteria donors after brain death and expanded criteria donors after circulatory death). The incidence of delayed graft function was significantly higher in expanded criteria donors after circulatory death than in the other groups (odds ratio = 6.9; 95% CI, 2.22-21.71; P < .001). Nevertheless, we found no significant differences in death-censored graft loss among the groups. Kidney transplants from expanded criteria donors and donors after cardiac death are comparable, even when both criteria are combined. The use of expanded criteria donor kidneys after cardiac death is therefore a suitable approach to expand the donor pool, despite the higher risk of delayed graft function, as there were no significant differences in death-censored graft loss.

Factors influencing kidney transplantation rates: a study from the ERA Registry.

Large international differences exist in kidney transplantation (KT) rates. We aimed to investigate which factors may explain the total, deceased donor and living donor KT rates over the last decade. KT experts from 39 European countries completed the Kidney Transplantation Rate Survey on measures and barriers and their potential effect on the KT rate in their country. In the analyses, countries were divided into low, middle and high KT rate countries based on the KT rate at the start of study period in 2010. Experts from low KT rate countries reported more frequently that they had taken measures regarding staff, equipment and facilities to increase the total KT rate compared with middle and high KT rate countries. For donor type-specific KT, the largest international differences in measures taken were reported for deceased donor KT, with middle and high KT rate countries taking more measures, such as the use of expanded criteria donor kidneys, the presence of transplantation coordinators and (inter)national exchange of donor kidneys. Once a measure was taken, experts' opinion on its success was similar across the low, middle and high KT rate countries. Experts from low KT rate countries more often reported potential barriers, such as patients' lack of knowledge and distrust in the healthcare system. Particularly in low KT rate countries, the KT rate might be stimulated by optimizing staff, equipment and facilities. In addition, all countries may benefit from measures specific to deceased and living donors.

Extracellular Vesicles Released During Normothermic Machine Perfusion Are Associated With Human Donor Kidney Characteristics.

Extracellular vesicles (EVs) are tissue-specific particles released by cells containing valuable diagnostic information in the form of various biomolecules. The characterization of EVs released by kidney grafts during normothermic machine perfusion (NMP) may present a promising avenue to assess graft status before transplantation. We phenotyped and determined the concentrations of EVs in the perfusate of 8 discarded expanded-criteria donor human kidneys during 6 h of NMP. Perfusate samples were taken at 0/60/180/360 min and examined with nanoparticle tracking analysis and imaging flow cytometry (IFCM). Using IFCM, EVs were identified by their expression of common EV markers CD9, CD63, and CD81 (tetraspanins) in combination with either platelet endothelial cell adhesion molecule (CD31), pan-leukocyte protein (CD45), or carboxyfluorescein succiminidyl ester (CFSE) fluorescence. Nanoparticle tracking analysis measurements revealed the release of nanoparticles <400 nm into the perfusate during NMP. With IFCM, tetraspanin protein signatures of the released nanoparticles were characterized, and the majority (~75%) of CFSE+ EVs were found to be CD81+, whereas ~16% were CD9+ and ~8% CD63+. Correlation analysis of concentrations of identified EV subsets with crude donor characteristics and NMP viability characteristics revealed significant correlations with cold ischemia time, donor age, and renal flow. Our findings demonstrate that discarded expanded-criteria donor kidney grafts release distinct EV subsets during NMP. Because these subsets correlate with well-established indicators of transplant outcome, EVs might represent new potential candidates for assessment of kidney graft quality.

Distinct global DNA methylation and NF-κB expression profile of preimplantation biopsies from ideal and non-ideal kidneys.

Epigenetic mechanisms may affect the ideal and non-ideal kidneys selected for transplantationand their inflammatory gene expression profile differently and may contribute to poor clinical outcomes. Study the Global DNA methylation and the expression profiles of the DNA methyltransferases (DNMTs) and nuclear factor kappa B (NF-κB) in preimplantation kidney biopsies from ideal and non-ideal kidneys (expanded criteria donor (ECD) and with KDPI > 85%). In a sample consistingof45 consecutive pre-implantation biopsies,global DNA methylation levels were detected by LINE-1 repeated elements using bisulfite pyrosequencing. DNMT gene expression was assessed by real-time quantitative polymerase chain reaction, and NF-κB protein expression by immunofluorescence. ECD kidneys displayed increased methylation levels in LINE-1, and DNMT1 and DNMT3B expression was upregulated when comparing ECD to standard criteria donor kidneys. Similarly, kidneys with KDPI > 85% exhibited increased LINE-1 methylation and DNMT1 upregulation when compared to a KDPI ≤ 85%. NF-κB protein expression levels were greatly increased in both types of non-ideal kidneys compared to ideal kidneys. Moreover, hypermethylation of LINE-1 was associated with cold ischemia time > 20h and ECD kidney classification. This study shows that global DNA hypermethylation and high expression of NF-κB occurred in both types of non-ideal kidneys and were associated with prolonged cold ischemia time. Global DNA methylation can be a useful tool to assess non-ideal kidneys and hence, could be used to expand the pool of kidneys donors.

344.3: Extracellular Vesicles Released During Normothermic Machine Perfusion Are Associated With Human Donor Kidney Characteristics

Background: Extracellular Vesicles (EVs) represent stable, tissue specific nano-sized particles that reflect the conditional state of their tissue of origin. Here, the dynamic release and phenotype of kidney EVs was characterized and quantified during Normothermic Machine Perfusion (NMP) of Expanded-Criteria Donor (ECD) kidneys to examine whether EVs could function as a potential biomarker for assessing kidney quality before transplantation. Materials & Methods: Eight discarded ECD kidneys (~13 ± 5 hours of cold ischemia, age 68 ± 7 (mean ± standard deviation), all male) were perfused in a closed system at 37 0C for 6 hours. Perfusates were taken before and at 1, 3 and 6 hours of NMP and examined with Nanoparticle Tracking Analysis (NTA) and Imaging Flow Cytometry (IFCM). For IFCM, perfusates were stained with the tetraspanins CD9, CD63 or CD81 (general EV markers), or a mix of these three markers in combination with CFDA-SE (a non-fluorescent molecule that acquires fluorescent properties after cleavage by intravesicular esterases) to identify, quantify and characterize EVs. Results: Analysis of perfusates with NTA revealed that the majority of nanoparticles present in the perfusates are <300 nm. For CFSE and the mix of tetraspanin double-positive EVs, we observed a ~700/ 740/ 560 fold increase compared to EV levels before perfusion at 1, 3 and 6 hours of NMP, respectively. Analysis of EV concentrations with crude donor characteristics (e.g. age, cold ischemia time (CIT), kidney weight) and NMP viability characteristics (renal flow, renal flow resistance, urine production) revealed that double-positive EV are negatively correlated with CIT whilst positive correlations were found with donor age after the first hour of NMP. Furthermore, tetraspanin CD81 was found to represent the majority (~75%) of the excreted double-positive EV (CD9: ~16%/ CD63 ~8%) (Figure). Conclusion: EVs <300 nm are released by ECD kidneys during NMP with highest excretion levels during the first hour of perfusion. Tetraspanin CD81 is predominantly present on these EVs, and EV concentrations were shown to be correlated with well-established indicators of kidney quality such as donor age and CIT. The characterization of the excreted EVs as well as their correlation with clinical parameters provide a starting point to study their role as potential biomarkers of kidney quality.

Expanded Criteria Donors.

The expanded criteria donor is any donor over the age of 60 years or a donor over the age of 50 years with 2 of the following 3 items: (1) history of high blood pressure, (2) serum creatinine ≥1.5 mg/dL, and (3) death due to stroke. To accept an expanded criteria donor kidney may significantly decrease the amount of time a person waits for transplant but requires written informed consent from the recipient. Although expanded criteria donor kidneys have predictably shorter outcomes than standard criteria donors, the exact risk is unknown. At 5 years follow-up, 50% of expanded criteria donor kidneys are still working. Regardless of donor status of these kidneys as expanded criteria or standard criteria, the transplant recipients have higher survival rates compared with candidates who remain on the wait list. The success rate may be increased when a perfusion pump is used to preserve the kidneys. Sometimes the function of a single kidney from an expanded criteria donor is deemed insufficient. In this situation, a pair of marginally functioning kidneys may be transplanted as a dual-kidney transplant. This dual transplant option offers acceptable outcomes as good as a single-kidney transplant with normal function and can effectively address the shortage of donor organs. The use of a perfusion pump allows the clinician to decide whether or not to use a particular expanded criteria donor kidney. Expanded criteria donors may be justified by meticulous selection of each donor for recipients, along with more sophisticated surgical techniques to maximize the kidney donor pool.

MP36-20 MULTI-PHOTON MICROSCOPY FOR THE EVALUATION OF INTERSTITIAL FIBROSIS IN EXTENDED CRITERIA DONOR KIDNEYS: A PROOF-OF-CONCEPT PILOT STUDY

You have accessJournal of UrologyCME1 May 2022MP36-20 MULTI-PHOTON MICROSCOPY FOR THE EVALUATION OF INTERSTITIAL FIBROSIS IN EXTENDED CRITERIA DONOR KIDNEYS: A PROOF-OF-CONCEPT PILOT STUDY Wei Zheng So, Jirong Lu, Benjamin Yen Seow Goh, Rachel Zui Chih Teo, Anantharaman Vathsala, and Ho Yee Tiong Wei Zheng SoWei Zheng So More articles by this author , Jirong LuJirong Lu More articles by this author , Benjamin Yen Seow GohBenjamin Yen Seow Goh More articles by this author , Rachel Zui Chih TeoRachel Zui Chih Teo More articles by this author , Anantharaman VathsalaAnantharaman Vathsala More articles by this author , and Ho Yee TiongHo Yee Tiong More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002590.20AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: This study evaluated the initial use of label free second harmonic generation (SHG) imaging with two photon excitation (2PE) auto-fluorescence for the quantification of collagen/fibrosis on pre-implantation biopsies of expanded criteria donors (ECD). METHODS: A total of 22 core ECD kidney transplant biopsy specimen tissues from 7 ECD donors, taken at the time of pre-implantation were retrieved, cut into 5-micron sections, mounted on slides and deparaffinized. The core needle biopsies were imaged with 2X and 20X objective using the commercially available laser-based Genesis® 200 (Histoindex Pte Ltd and Clinnovate Pte Ltd, Singapore). The entire core was selected as the Region of Interest (ROI). Corresponding clinical information from transplant donors were retrieved. Pathological review was performed, and all biopsies had Interstitial Fibrosis (IF)/Tubular Atrophy (TA) scores > 0. Collagen parameters measured included quantification by the Collagen Area Ratio in Tissue (CART), and qualitative measurements by Collagen Reticulation Index (CRI). RESULTS: 22 core biopsies were extracted from 14 donor kidney samples, of which originated from 7 donors. Table 1 depicts the baseline ECD characteristics of the donors. For the 8 kidneys with multiple biopsies done, we obtained an average score of the collagen parameters across the different samples. Biopsies classified with >85% KDPI score had significantly higher CAR and CART than biopsies with ≤85% KDPI score (Table 2). CONCLUSIONS: MPM is an evolving technology that enables the quantification of the amount (CART) and quality (CRI) of collagen deposition in unstained explant biopsies of ECD kidneys. This initial evaluation found significant difference in both parameters between ECD donors with more or less than 85% KDPI. Source of Funding: None © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e605 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Wei Zheng So More articles by this author Jirong Lu More articles by this author Benjamin Yen Seow Goh More articles by this author Rachel Zui Chih Teo More articles by this author Anantharaman Vathsala More articles by this author Ho Yee Tiong More articles by this author Expand All Advertisement PDF DownloadLoading ...

Early experiments with hypothermic oxygenated machine perfusion of kidney grafts from extended criteria donors

Objective: to evaluate the safety and efficacy of hypothermic oxygenated machine perfusion (HOPE) for kidney grafts obtained from expanded criteria donors (ECD).Materials and methods. From June 2018 to June 2021, 200 surgeries involving kidney transplants from deceased donors were performed at Botkin City Clinical Hospital. Of these, 123 were men (61.5%) and 77 were women (38.5%). The mean age was 47.62 ± 11.69 (20–73) years. In 102 cases, kidney grafts were procured from ECD. In 92 recipients (90.2%) of kidney transplants from an expanded criteria donor, static cold storage done according to the standard technique was used to preserve the organ; these patients constituted observation group 1. In 10 recipients (9.8%), hypothermic oxygenated perfusion was used in addition to static cold preservation; these patients formed observation group 2.Results. No 30-day mortality was recorded in both observation groups. The mean static cold storage time in group 1 patients was 612.33 ± 178.88 (133–1180) minutes. Overall incidence of delayed graft function was 26.5% (53/200). Incidence of delayed graft function was 19.3% (19/98) for organs from standard donors using static cold storage and 35.8% (33/92) for ECD organs. Twenty-five patients (12.5%) had postoperative complications. Postoperative complications with delayed graft function were diagnosed in 12 patients, which was 22.6% (12/53), with immediate function in 13 patients, which was 8.8% (13/147). Mean cold storage time in group 2 patients was 319.11 ± 110.24 (311–525) minutes. Mean HOPE time was 202.34 ± 21.48 (150–210) minutes. Delayed graft function was recorded in 1 group 2 patient (10%). No complications, including perfusion-related one, were recorded in this group.Conclusion. The unique technique used at Botkin City Clinical Hospital for HOPE in kidney transplant is safe. It provides a low risk of delayed graft function for ECD kidneys.

A Review of Current and Emerging Trends in Donor Graft-Quality Assessment Techniques.

The number of patients placed on kidney transplant waiting lists is rapidly increasing, resulting in a growing gap between organ demand and the availability of kidneys for transplantation. This organ shortage has forced medical professionals to utilize marginal kidneys from expanded criteria donors (ECD) to broaden the donor pool and shorten wait times for patients with end-stage renal disease. However, recipients of ECD kidney grafts tend to have worse outcomes compared to those receiving organs from standard criteria donors (SCD), specifically increased risks of delayed graft function (DGF) and primary nonfunction incidence. Thus, representative methods for graft-quality assessment are strongly needed, especially for ECDs. Currently, graft-quality evaluation is limited to interpreting the donor’s recent laboratory tests, clinical risk scores, the visual evaluation of the organ, and, in some cases, a biopsy and perfusion parameters. The last few years have seen the emergence of many new technologies designed to examine organ function, including new imaging techniques, transcriptomics, genomics, proteomics, metabolomics, lipidomics, and new solutions in organ perfusion, which has enabled a deeper understanding of the complex mechanisms associated with ischemia-reperfusion injury (IRI), inflammatory process, and graft rejection. This review summarizes and assesses the strengths and weaknesses of current conventional diagnostic methods and a wide range of new potential strategies (from the last five years) with respect to donor graft-quality assessment, the identification of IRI, perfusion control, and the prediction of DGF.

Early Graft Loss Following Transplantation From Expanded Criteria Donors.

Expanded criteria donor (ECD) kidneys are associated with higher graft loss rates than standard criteria donor kidneys. We sought to determine factors associated with early graft loss and their discrimination ability for this outcome compared with kidney donor risk index. Data were extracted from the Australia and New Zealand Dialysis and Transplant Registry (ANZDATA) for ECD transplants between 1997 and 2014. The primary outcome was early graft loss (all-cause graft loss within 3 y of transplantation). Death-censored graft loss was substituted as a sensitivity analysis. Era-adjusted odds ratios were calculated by multivariable logistic regression for donor, recipient, and transplant factors available at transplantation. Discrimination was assessed by c-statistic, with 95% confidence intervals (CIs) calculated by bootstrapping. Of 2152 ECD kidney transplants, early graft loss occurred in 406 (19%) and was associated with recipient diabetes, smoking, First Nations recipients, and oliguria. Of factors defining ECD (age, elevated terminal creatinine, hypertension, death from cerebrovascular accident), all but mode of death were associated with early graft loss. The multivariable model, including known donor, recipient, and transplant factors, was moderately good at predicting early graft loss (c-statistic 0.65; 95% CI, 0.62-0.68). Recipient factors (c-statistic 0.62; 95% CI, 0.59-0.65) performed equally well compared with donor factors (c-statistic 0.60; 95% CI, 0.57-0.64) or the kidney donor risk index (c-statistic 0.60; 95% CI, 0.56-0.63). Early graft loss occurs in approximately one-fifth of ECD kidney transplants. The discriminatory value of commonly used recipient, donor, and transplant factors are approximately comparable and limited.

Clinical Correlates and Outcomes of Dual Basiliximab and Antithymocyte Globulin Induction in Kidney Transplant Recipients: A National Study.

We used national transplant registry data to study clinical correlates and outcomes of single versus dual induction therapy in adult kidney-only transplant recipients in the United States (2005-2018). The risk of death and graft loss at 1 and 5 y, according to induction therapy type, was assessed using multivariate Cox regression analysis (adjusted hazard ratio with 95% upper and lower confidence limits [LCLaHRUCL]). Of the 157 351 recipients included in the study, 67% were treated with ATG alone, 29% were treated with IL2rAb alone, and 5% were treated with both. Compared with IL2rAb alone, the strongest correlates of dual induction included Black race, calculated panel reactive antibody ≥80%, prednisone-sparing maintenance immunosuppression, more recent transplant eras, longer cold ischemia time, and delayed graft function. Compared with ATG alone, dual induction was associated with an increased 5-y risk of death (aHR 1.071.151.23; P < 0.0001), death-censored graft failure (aHR 1.051.131.22; P < 0.05), and all-cause graft failure (aHR 1.061.121.18; P < 0.0001). Further research is needed to develop risk-prediction tools to further inform optimal, individualized induction protocols for kidney transplant recipients.

A kidney discard decision strategy based on zero-time histology analysis could lead to an unjustified increase in the organ turndown rate among ECD.

The utility of zero-time kidney biopsies (KB) in deciding to accept expanded criteria donor (ECD) kidneys remains controversial. However, zero-time histology is one of the main causes for discarding kidneys in the United States. In a single-centre study, we examined the utility and impact on outcome of the use of frozen section zero-time KB among ECD. Ninety-two zero-time KB were analysed for accept/discard decision between 2005 and 2015 among ECD. 53% of kidneys were rejected after zero-time KB analysis; there was no difference in individual clinical and biological data between accepted/rejected groups. However, histology of rejected kidneys showed more sclerotic glomeruli (20% vs. 8%; P<0.001), increased interstitial fibrosis (1.25±0.12 vs. 0.47±0.09; P<0.0001), more arteriosclerosis (2.14±0.17 vs. 1.71±0.11; P=0.0032) and arteriolar hyalinosis (2.15±0.12 vs. 1.55±0.11; P=0.0006). Using propensity score matching, we generated a group of 42 kidney allograft recipients who received a transplant matched for donor zero-time histology and clinical characteristics with donors whose kidneys were rejected. Interestingly, their 1- and 5-year graft survival and function were similar to the global cohort of ECD recipients. In conclusion, when performed, zero-time KB was a decisive element for kidney discard decision. However, adverse zero-time histology was not associated with poorer graft survival and kidney function among ECD.

Oxygenated End-Hypothermic Machine Perfusion in Expanded Criteria Donor Kidney Transplant

Continuous hypothermic machine perfusion during organ preservation has a beneficial effect on graft function and survival in kidney transplant when compared with static cold storage (SCS). To compare the effect of short-term oxygenated hypothermic machine perfusion preservation (end-HMPo2) after SCS vs SCS alone on 1-year graft survival in expanded criteria donor kidneys from donors who are brain dead. In a prospective, randomized, multicenter trial, kidneys from expanded criteria donors were randomized to either SCS alone or SCS followed by end-HMPo2 prior to implantation with a minimum machine perfusion time of 120 minutes. Kidneys were randomized between January 2015 and May 2018, and analysis began May 2019. Analysis was intention to treat. On randomization and before implantation, deceased donor kidneys were either kept on SCS or placed on HMPo2. Primary end point was 1-year graft survival, with delayed graft function, primary nonfunction, acute rejection, estimated glomerular filtration rate, and patient survival as secondary end points. Centers in 5 European countries randomized 305 kidneys (median [range] donor age, 64 [50-84] years), of which 262 kidneys (127 [48.5%] in the end-HMPo2 group vs 135 [51.5%] in the SCS group) were successfully transplanted. Median (range) cold ischemia time was 13.2 (5.1-28.7) hours in the end-HMPo2 group and 12.9 (4-29.2) hours in the SCS group; median (range) duration in the end-HMPo2 group was 4.7 (0.8-17.1) hours. One-year graft survival was 92.1% (n = 117) in the end-HMPo2 group vs 93.3% (n = 126) in the SCS group (95% CI, -7.5 to 5.1; P = .71). The secondary end point analysis showed no significant between-group differences for delayed graft function, primary nonfunction, estimated glomerular filtration rate, and acute rejection. Reconditioning of expanded criteria donor kidneys from donors who are brain dead using end-HMPo2 after SCS does not improve graft survival or function compared with SCS alone. This study is underpowered owing to the high overall graft survival rate, limiting interpretation. isrctn.org Identifier: ISRCTN63852508.

Impact of pre-transplant biopsy on 5-year outcomes of expanded criteria donor kidney transplantation.

Compared to Standard Criteria Donors (SCD), Expanded Criteria Donor (ECD) kidneys are associated with poorer outcomes, although pre-transplant biopsy may mitigate risks. This study assessed 5-year outcomes of deceased-donor kidney transplant recipients, comparing recipients of ECD allografts evaluated histologically to recipients of SCD and ECD kidneys assessed clinically. This is a single-centre retrospective study. From November 2005 to December 2009 (Era 1), donors were assessed clinically for suitability for kidney donation. From December 2009 to October 2017 (Era 2), kidneys from ECDs and diabetics underwent pre-transplant biopsy and were allocated based on Remuzzi score. Outcomes of Era 1 and 2 recipients were compared. ECD kidney transplantation increased from 30.4% to 40.0% from Era 1 to 2. Univariable Cox regression, stratified by transplant era, found that 5-year graft loss was highest with Era 1 ECD (HR 2.5, 95% CI 1.1-5.5, P = .027) while graft loss for Era 2 ECD recipients was similar to SCD recipients. There was no difference in 5-year recipient survival. Amongst Era 1 ECD recipients, 51.2% experienced rejection compared to 30.8-41.5% for other subgroups. Five-year eGFR was higher with Era 2 ECD at 48.4 (33.3-60.7) ml/min/1.73 m2 compared to 42.2 (35.8-57.3) ml/min/1.73 m2 for Era 1 ECD. However, these differences were not statistically significant. Introduction of pre-transplant biopsy assessment may be associated with improved outcomes of ECD kidney recipients such that they are now comparable to SCD kidney recipients, with benefits persisting over 5 years.

Ex vivo delivery of Mirococept: A dose-finding study in pig kidney after showing a low dose is insufficient to reduce delayed graft function in human kidney.

The complement system plays a pivotal role in the pathogenesis of ischemia-reperfusion injury in solid organ transplantation. Mirococept is a potent membrane-localizing complement inhibitor that can be administered ex vivo to the donor kidney prior to transplantation. To evaluate the efficacy of Mirococept in reducing delayed graft function (DGF) in deceased donor renal transplantation, we undertook the efficacy of mirococept (APT070) for preventing ischaemia-reperfusion injury in the kidney allograft (EMPIRIKAL) trial (ISRCTN49958194). A dose range of 5-25mg would be tested, starting with 10mg in cohort 1. No significant difference between Mirococept at 10mg and control was detected; hence the study was stopped to enable a further dose saturation study in a porcine kidney model. The optimal dose of Mirococept in pig kidney was 80mg. This dose did not induce any additional histological damage compared to controls or after a subsequent 3hours of normothermic machine perfusion. The amount of unbound Mirococept postperfusion was found to be within the systemic dose range considered safe in the Phase I trial. The ex vivo administration of Mirococept is a safe and feasible approach to treat DGF in deceased donor kidney transplantation. The porcine kidney study identified an optimal dose of 80mg (equivalent to 120mg in human kidney) that provides a basis for further clinical development.