The Influence of Deceased Donor Age and Old-for-Old Allocation on Kidney Transplant Outcome

Outcome of kidney transplantation from senior deceased donors: a single centre study

BACKGROUND

Addressing the current demographic development, the efficacy and safety of kidney transplantations from very senior donors needs to be carefully evaluated. The aim of this study was to analyse patient and graft outcomes of kidney allograft recipients stratified by donor age.

METHODS

We retrospectively investigated n = 491 patients from a prospective, observational renal transplant cohort. Patients with kidneys from very old donors (n = 75, aged >70 years), elderly donors (n = 158, between 60-70 years), and regular donors (n = 258, aged <60 years) were investigated. The primary outcome was death-censored graft survival within the predefined donor age groups.

RESULTS

Overall, n = 57 death-censored graft losses occurred. Graft loss was proportionally highest in the very old donor group (n = 11/75), but this did not reach statistical significance when compared to the elderly (14/158) and regular donor groups (32/258); (p = 0.37). Kaplan-Meier analysis demonstrated that 3-year/5-year death-censored graft survival in the very old donor group was 96%/86% and did not differ from the other age groups (p = 0.44). Median estimated glomerular filtration rate (eGFR), calculated by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula (in ml/min/1.73 m2 of body surface) 12 months post-transplant did not differ between the elderly donor and very old donor groups (p = 0.53). However, patients who received regular donor kidneys had higher median eGFR compared to recipients in both the elderly and very old donor groups (p <0.0001). During follow-up, 31% of patients developed at least one acute rejection episode. Time-to-event analysis demonstrated no difference in occurrence of any acute rejection event across all three groups (p = 0.11).

CONCLUSIONS

This study demonstrates that kidney transplantation from carefully selected very old donors seems a valid option with reasonable short- and mid-term outcomes.

Kidney Transplantation Outcome Predictions (KTOP): A Risk Prediction Tool for Kidney Transplants from Brain-dead Deceased Donors Based on a Large European Cohort

BACKGROUND

European kidney donation shortages mandate efficient organ allocation by optimizing the prediction of success for individual recipients.

OBJECTIVE

To develop the first European online risk tool for kidney transplant outcomes on the basis of recipient-only and recipient plus donor characteristics.

DESIGN, SETTING, AND PARTICIPANTS

We used individual recipient and donor risk factors and three outcomes (death, death with functioning graft [DWFG], and graft loss) for 32 958 transplants within the Eurotransplant kidney allocation system and the Eurotransplant senior program between January 2006 and May 2018 in eight European countries to develop and validate a risk tool.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Cox proportional-hazards models were used to analyze the association of risk factors with overall patient mortality, and proportional subdistribution hazard regression models for their association with graft loss and DWFG. Prediction models were developed with recipient-only and recipient-donor risk factors. Sensitivity analyses based on time-specific area under the receiver operating characteristic curve (AUC) with leave-one-country-out validation were performed and calibration plots were generated.

RESULTS AND LIMITATIONS

The 10-yr cumulative incidence rate was 37% for mortality, 12% for DWFG, and 41% for graft loss. In recipient-donor models the leading risk factors for mortality were recipient diabetes (hazard ratio [HR] 10.73), retransplantation (HR 3.08 per transplant), and recipient age (HR 1.08). Effects were similar for DWFG. For graft loss, diabetes (subdistributional HR [SHR] 1.32), increased donor age (SHR 1.02), and prolonged cold ischemia time (SHR 1.02) had increased SHRs. All p values were <0.001.

CONCLUSIONS

Previously identified risk factors for outcomes following kidney transplants allow for outcome prediction with 10-yr AUC values of up to 0.81.

PATIENT SUMMARY

Using European data, we estimated individual risks to predict the success of kidney transplants and support physicians in decision-making. An online tool is now available (https://riskcalc.org/ktop/) for predicting kidney transplant outcomes both before and after a donor has been identified.

Recipient efficacy and safety of kidney transplantation from older living donor: consideration for using older kidney as a solution to the shortage of organs

Background

As a solution to organ shortages, studies on kidney transplantation (KT) from older donors are being conducted. However, many controversies remain about its safety and efficacy.

Methods

In Samsung Medical Center, from January 2000 to May 2015, 1,141 patients underwent living KT. Cases of retransplantation, recipient and donor aged younger than 18 years, and multiorgan transplantation were excluded, and a total of 859 cases were selected. Analysis was performed by dividing the patents into two groups a younger donor group (donors <60 years old; n=826) and an older donor group (donors ≥60 years old; n=33).

Results

There were no significant differences between the two groups in patient death (log-rank P=0.173) or in postoperative complications. The older donor group had a higher acute rejection (P=0.034; hazard ratio [HR], 1.704) and graft failure rate (P=0.029, HR=2.352). There was no significant difference in the trend of estimated glomerular filtration rate over time (P=0.189).

Conclusions

KT using kidneys from old-aged donors is safe, but there is room for improvement due to problems with higher acute rejection and graft failure rate.

Effect of Utilizing More Than 20-Year Older Deceased Donor Kidneys for Young Recipients: An Analysis of the UK Registry

OBJECTIVES

Despite the wider acceptance of expanded criteria kidneys and the advances in immunosuppression, clinicians remain sceptical when it comes to accepting kidneys from significantly older donors, especially for the young adult recipient population (age ≤40 years).

MATERIALS AND METHODS

We utilized prospectively maintained data from the United Kingdom Registry and analyzed the deceased donor renal transplant outcomes for 2 cohorts: (1) young recipients who received either a younger kidney or a kidney from a donor who was less than 20 years older (group <20; n = 2072) and (2) young recipients who received a kidney from donors who were 20 or more years older (group ≥20, n = 764). We used life tables for survival and performed Cox regression analysis to identify significant variables.

RESULTS

Median follow-up was 2918 days. The univariate analysis for graft loss showed the strongest predictors to be donor age, recipient age, recipient ethnicity, and delayed graft function, which retained their significance in the multivariate model. Graft survival rates were 94% versus 90% at 1 year, 86% versus 75% at 5 years, and 75% versus 63% at 10 years for group <20 versus group ≥20, respectively. Respective patient survival rates were comparable for both cohorts: 99% versus 98% at 1 year, 97% versus 96% at 5 years, and 91% versus 91% at 10 years.

CONCLUSIONS

Our analysis showed that allografts from ≥20-year-older deceased donors are beneficial and should be considered for transplant in younger recipients. Allograft survival may be worse compared with survival with younger allografts; however, young recipients do potentially better and survive longer compared with remaining on dialysis.

Outcome of kidney transplantation from very senior donors in Switzerland - a national cohort study

Kidney transplantation from older and marginal donors is effective to confront organ shortage. However, limitations after transplantation of kidneys from very marginal kidney donors remain unclear. We compared patient and graft outcome, achieved allograft function and quality of life of renal transplantations from Very Senior Donors (VSD, defined as donors aged 70 years and older) with Senior Donors (SD, aged 60-70 years) and Regular Donors (RD, aged younger than 60 years) in Switzerland. We evaluated the outcome of 1554 adult recipients of deceased donor kidney transplantations from 05/2008 to 12/2019; median follow-up was 4.7 years. Failure-free survival (freedom from graft loss or death), glomerular filtration rate (eGFR), and quality of life at 12 months were analyzed for RD (reference group, n = 940), SD (n = 404), and VSD (n = 210). Failure-free survival decreased with increasing donor age, mainly attributable to premature graft loss. Still, overall 5-year failure-free survival reached 83.1%, 81.0%, and 64.0% in the RD, SD, and VSD subgroups, respectively. eGFR 12 months post-transplantation was significantly higher in RD compared with SD and VSD. The acceptance rate of donor candidates for kidney TPL was 78% for the entire cohort (87% for RD, 79% for SD, and 56% for VSD). Deceased donor kidney transplantation from donors aged 70 years or older is associated with an inferior, yet acceptable failure-free outcome, with sustained quality of life.

The Association Between Macroscopic Arteriosclerosis of the Renal Artery, Microscopic Arteriosclerosis, Organ Discard, and Kidney Transplant Outcome

Supplemental Digital Content is available in the text.

Background.

During organ retrieval, surgeons estimate the degree of arteriosclerosis and this plays an important role in decisions on organ acceptance. Our study aimed to elucidate the association between macroscopic renal artery arteriosclerosis, donor kidney discard, and transplant outcome.

Methods.

We selected all transplanted and discarded kidneys in the Netherlands between January 1, 2000, and December 31, 2015, from deceased donors aged 50 y and older, for which data on renal artery arteriosclerosis were available (n = 2610). The association between arteriosclerosis and kidney discard, the relation between arteriosclerosis and outcome, and the correlation between macroscopic and microscopic arteriosclerosis were explored.

Results.

Macroscopic arteriosclerosis was independently associated with kidney discard (odds ratio [OR], 1.36; 95% confidence interval [CI], 1.02-1.80; P = 0.03). Arteriosclerosis (any degree) was not significantly associated with delayed graft function (OR, 1.16; 95% CI, 0.94-1.43; P = 0.16), estimated glomerular filtration rate 1-y posttransplant (B, 0.58; 95% CI, –2.07 to 3.22; P = 0.67), and long-term graft survival (hazard ratio, 1.07; 95% CI, 0.86-1.33; P = 0.55). There was a significant association between mild arteriosclerosis and primary nonfunction (OR, 2.14; 95% CI, 1.19-3.84; P = 0.01). We found no correlation between macroscopic and histological arteriosclerosis, nor between histological arteriosclerosis and transplant outcome.

Conclusions.

Macroscopic arteriosclerosis of the renal artery was independently associated with kidney discard and somewhat associated with primary nonfunction posttransplant. However, there was no effect of arteriosclerosis on delayed graft function, estimated glomerular filtration rate at 1 y, or long-term graft survival. Our results are valid only after inevitable exclusion of discarded kidneys that had on average more arteriosclerosis. Hence, conclusions should be interpreted in the light of this potential bias.

Expanded criteria donors in deceased donor kidney transplantation - An Asian perspective

There is an increasing gulf between demand and supply for kidneys in end-stage renal failure patients worldwide, especially Asia. Renal transplantation is often the treatment of choice for long-suffering patients who have to undergo dialysis on a regular basis. The utilization of expanded criteria donors (ECDs) to address the donor pool shortage has been proven to be a legitimate solution. Metzger first described the classification of standard criteria donor and ECD in 2002. Since then, the criterion has undergone various modifications, with the key aims of optimizing organ procurement rate while minimizing discard and rejection rates. We review the methods to improve selection, characterization of risks, and surgical techniques. Although the ECD kidneys have a higher risk of impaired donor and recipient outcome than the "standard criteria" transplants, it may be justified by the improved overall survival of these patients compared to those who remained on dialysis. It is, therefore, crucial that we perform meticulous selection, along with state of the art surgical techniques to maximize the use of this scarce resource. In this article, we review the pre-procurement and post-procurement processes implemented to preserve outcomes.

Impacto de la perfusión hipotérmica pulsativa en el injerto renal de donante subóptimo: nuestra experiencia inicial

Objetivo: Estudios recientes han demostrado que el mantenimiento de la viabilidad de riñones con criterios expandidos durante su preservación sea un reto. La máquina de perfusión hipotérmica pretende mitigar el efecto del almacenamiento en frío sobre la calidad del órgano cuando el tiempo de isquemia fría es prolongada o el donante subóptimo.Objetivo: Evaluar las complicaciones que presentan los pacientes trasplantados renales con preservación está-tica fría o perfusión hipotérmica pulsátil.Material y Método: Estudio observacional retrospec-tivo durante 2010-2012 donde se incluyeron todos los trasplantes renales realizados en un hospital de tercer nivel. Las variables de estudio: estancia hospitalaria, horas de isquemia, necesidad de diálisis y número de sesiones post trasplante y el dispositivo de almacena-miento, edad y patologías asociadas al donante.Resultados: Se realizaron 175 trasplantes donde 70 procedieron de donantes ≥65 años. Se perfundieron en máquina 30 riñones y en 40 se utilizó la preservación estática. Nuestros hallazgos respecto al uso de la má-quina de perfusión conllevan un descenso en la estancia media hospitalaria y una menor necesidad de hemodiá-lisis postrasplante.Conclusiones: Debido al alto porcentaje de órganos procedentes de donantes de edad avanzada y difíciles de preservar, resulta fundamental buscar técnicas de perfusión intravascular continua para una preservación más efectiva del órgano.

Significant Reduction of Murine Renal Ischemia-Reperfusion Cell Death Using the Immediate-Acting PrC-210 Reactive Oxygen Species Scavenger

Background.

Ischemia-reperfusion (IR) injury remains a significant problem for all solid organ transplants; thus, an important unmet need in transplantation is the prevention of IR injury. PrC-210 has demonstrated superior prevention of reactive oxygen species damage in several preclinical studies as a free radical scavenger. Here, we describe its profound efficacy in suppressing IR injury in a murine model of kidney IR injury.

Methods.

C57/B6 mice underwent laparotomy with the left renal pedicle occluded for 30 minutes to induce IR injury. Right nephrectomy was performed at the time of surgery. Mice received a single systemic dose of the PrC-210, PrC-211, or PrC-252 aminothiols 20 minutes before IR injury. Twenty-four hours following IR injury, blood and kidney tissue were collected for analysis. Kidney caspase-3 level (a marker of cell death), direct histological analysis of kidneys, and serum blood urea nitrogen (BUN) were measured in animals to assess reactive oxygen species scavenger protective efficacies.

Results.

A single systemic PrC-210 dose 20 minutes before IR injury resulted in significant reductions in (1) IR-induced kidney caspase level (P < 0.0001); caspase was reduced to levels not significantly different than control caspase levels seen in unperturbed kidneys, (2) IR-induced renal tubular injury scores (P < 0.0001); brush border loss and tubular dilation were markedly reduced, and (3) serum BUN compared with control IR injury kidneys (P < 0.0001). The ranked protective efficacies of PrC-210 > PrC-211 >> PrC-252 paralleled previous radioprotection studies of the molecules.

Conclusions.

A single PrC-210 dose, minutes before the IR insult, profoundly reduced caspase, renal tubular injury, and serum BUN in mice exposed to standard kidney IR injury. These findings support further development of the PrC-210 molecule to suppress or prevent IR injury in organ transplant and other IR injury settings.

Kidney transplant registries: How to optimise their utility?

The scientific Registries (RE) in renal transplantation (Tx) are very useful since they allow us to identify risk factors in this population and facilitate contrasting the information with other national and international registries, contributing to establishing strategies which improve outcomes in terms of survival. They constitute an organised and planned system that uses observational methods and standardised systematic processes, including adjusted risk models, to essentially evaluate survival outcomes. The scientific RE are complemented with clinical trials providing scientific evidence, but inexcusably need adequate statistical analysis to generate reliable clinical data that contribute to optimising the prognosis of the transplant population. In addition, scientific RE provide valuable information on the performance of Tx programmes and help generate prognostic indexes, which could contribute to improving survival. Under these prerequisites, this review will assess the following aspects related to the scientific RE in the Tx: 1) the concept and importance of implementing RE in Tx; 2) the measures that are needed for the correct execution of the scientific RE; 3) the benefits, quality and limitations of RE; 4) the statistical tools for the adequate analysis of survival; and 5) utility of RE in the evaluation of performance, quality and surveillance of transplant programmes and the generation of comorbidity índices.

The impact of donor/recipient age difference and HLA mismatch on graft outcome in pediatric kidney transplantation

BACKGROUND

Understanding the relationship between the factors that influence long-term kidney transplant survival remains a key priority for pediatric nephrologists. We assessed the relative impact of donor/recipient age difference and HLA matching on long-term graft outcomes.

METHODS

We conducted a retrospective cohort study of pediatric and adolescent recipients who received a primary kidney transplant in Australia and New Zealand between January 1, 1990, and December 31, 2015. The primary outcome was graft survival analyzed by Kaplan-Meier method.

RESULTS

During the 26-year period, 1134 primary (395 DD and 739 LD) kidney transplants were performed in recipients less than 20 years of age. The median follow-up time was 10.2 years. Overall, 405 patients (35.7%) lost their transplant with graft survival 93.8% at 1 year, 82.5% at 5 years, 65.8% at 10 years, and 49.9% at 15 years post-transplant. There was consistently higher graft loss of DD kidneys as compared to LD kidneys at each time point. Both increasing donor/recipient age difference (aHR 1.11 per 10 years; 95% CI, 1.02-1.20; P = 0.009) and increasing HLA mismatch (aHR 1.20 per mismatch; 95% CI, 1.10-1.30; P < 0.001) were associated with decreased graft survival.

CONCLUSIONS

Donor/recipient age difference and HLA matching are important factors influencing long-term graft outcomes in pediatric kidney transplantation. HLA mismatch remains a strong predictor of graft loss. For patients without the option of a LD, we suggest that the degree of HLA mismatch should not be discounted as part of the decision-making process of organ allocation.

Graft Pre-conditioning by Peri-Operative Perfusion of Kidney Allografts With Rabbit Anti-human T-lymphocyte Globulin Results in Improved Kidney Graft Function in the Early Post-transplantation Period-a Prospective, Randomized Placebo-Controlled Trial

Introduction: Although prone to a higher degree of ischemia reperfusion injury (IRI), the use of extended criteria donor (ECD) organs has become reality in transplantation. We therefore postulated that peri-operative perfusion of renal transplants with anti-human T-lymphocyte globulin (ATLG) ameliorates IRI and results in improved graft function.

Methods: We performed a randomized, single-blinded, placebo-controlled trial involving 50 kidneys (KTx). Prior to implantation organs were perfused and incubated with ATLG (AP) (n = 24 kidney). Control organs (CP) were perfused with saline only (n = 26 kidney). Primary endpoint was defined as graft function reflected by serum creatinine at day 7 post transplantation (post-tx).

Results: AP-KTx recipients illustrated significantly better graft function at day 7 post-tx as reflected by lower creatinine levels, whereas no treatment effect was observed after 12 months surveillance. During the early hospitalization phase, 16 of the 26 CP-KTx patients required dialysis during the first 7 days post-tx, whereas only 10 of the 24 AP-KTx patients underwent dialysis. No treatment-specific differences were detected for various lymphocytes subsets in the peripheral blood of patients. Additionally, mRNA analysis of 0-h biopsies post incubation with ATLG revealed no changes of intragraft inflammatory expression patterns between AP and CP organs.

Conclusion: We here present the first clinical study on peri-operative organ perfusion with ATLG illustrating improved graft function in the early period post kidney transplantation.

Clinical Trial Registration:www.ClinicalTrials.gov, NCT03377283

Hypothermic Machine Perfusion Results in a Marginal Kidney Transplant Programme

BACKGROUND

Hypothermic machine perfusion (HMP) of deceased donor kidneys is associated with a better outcome than static cold storage, predominantly in marginal donors. Nevertheless, there is little evidence supporting whether graft centre of origin and donor category impact HMP results.

OBJECTIVE

To identify factors impacting HMP in transplantation from marginal donors.

DESIGN, SETTING, AND PARTICIPANTS

Analysis of prospectively collected cohort data of expanded criteria donor (ECD) and donor after circulatory death (DCD) categories II and III was performed. A total of 214 adult recipients of first kidney transplantation with complete data and a minimum of 6-mo follow-up were included.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Delayed graft function (DGF) was defined as the lack of decrease in creatinine level in the first 48h. Graft loss was defined as return to dialysis or creatinine clearance <15ml/min/1.73m². Univariate and multivariate logistic regression analyses for DGF were constructed to identify independent risk factors. Recipient and graft survival (GS) analyses were conducted by Kaplan-Meier, and univariate and multivariate Cox regression analyses.

RESULTS AND LIMITATION

DGF occurred in 32.8% of imported and 20.5% of local grafts (p=0.059). Only donor category (DCD; odds ratio [OR]: 6.6, p=0.008) and haemodialysis (OR: 3.5, p=0.002) were significantly associated with DGF development. The 1-yr GS rate was 92.5% in the local donor group and 84.3% in the imported donor group (p=0.050). Multivariate analysis by Cox proportional hazards model identified only donor category (hazard ratio [HR] 10.99, p=0.001) and donor age (HR 1.07, p=0.005) as predictive variables for GS. The small sample size of the DCD group diminished the statistical power and did not permit a subgroup analysis to determine the impact of specific DCD category on HMP results.

CONCLUSIONS

DCD donor category, but not donor centre of origin, impacted DGF development and GS in the HMP of deceased donor kidneys.

PATIENT SUMMARY

Currently, the number of donors is insufficient to meet the demand for renal grafts. Expanded criteria for donation after brain death and donation after circulatory death (DCD) programmes have been developed as strategies to minimise this problem. Hypothermic machine perfusion has previously demonstrated its usefulness in expanded criteria donation and DCD preservation. DCD type and donor age increase the risk of graft loss.

Methods for the evaluation of biomarkers in patients with kidney and liver diseases: multicentre research programme including ELUCIDATE RCT

Background

Protein biomarkers with associations with the activity and outcomes of diseases are being identified by modern proteomic technologies. They may be simple, accessible, cheap and safe tests that can inform diagnosis, prognosis, treatment selection, monitoring of disease activity and therapy and may substitute for complex, invasive and expensive tests. However, their potential is not yet being realised.

Design and methods

The study consisted of three workstreams to create a framework for research: workstream 1, methodology – to define current practice and explore methodology innovations for biomarkers for monitoring disease; workstream 2, clinical translation – to create a framework of research practice, high-quality samples and related clinical data to evaluate the validity and clinical utility of protein biomarkers; and workstream 3, the ELF to Uncover Cirrhosis as an Indication for Diagnosis and Action for Treatable Event (ELUCIDATE) randomised controlled trial (RCT) – an exemplar RCT of an established test, the ADVIA Centaur® Enhanced Liver Fibrosis (ELF) test (Siemens Healthcare Diagnostics Ltd, Camberley, UK) [consisting of a panel of three markers – (1) serum hyaluronic acid, (2) amino-terminal propeptide of type III procollagen and (3) tissue inhibitor of metalloproteinase 1], for liver cirrhosis to determine its impact on diagnostic timing and the management of cirrhosis and the process of care and improving outcomes.

Results

The methodology workstream evaluated the quality of recommendations for using prostate-specific antigen to monitor patients, systematically reviewed RCTs of monitoring strategies and reviewed the monitoring biomarker literature and how monitoring can have an impact on outcomes. Simulation studies were conducted to evaluate monitoring and improve the merits of health care. The monitoring biomarker literature is modest and robust conclusions are infrequent. We recommend improvements in research practice. Patients strongly endorsed the need for robust and conclusive research in this area. The clinical translation workstream focused on analytical and clinical validity. Cohorts were established for renal cell carcinoma (RCC) and renal transplantation (RT), with samples and patient data from multiple centres, as a rapid-access resource to evaluate the validity of biomarkers. Candidate biomarkers for RCC and RT were identified from the literature and their quality was evaluated and selected biomarkers were prioritised. The duration of follow-up was a limitation but biomarkers were identified that may be taken forward for clinical utility. In the third workstream, the ELUCIDATE trial registered 1303 patients and randomised 878 patients out of a target of 1000. The trial started late and recruited slowly initially but ultimately recruited with good statistical power to answer the key questions. ELF monitoring altered the patient process of care and may show benefits from the early introduction of interventions with further follow-up. The ELUCIDATE trial was an ‘exemplar’ trial that has demonstrated the challenges of evaluating biomarker strategies in ‘end-to-end’ RCTs and will inform future study designs.

Conclusions

The limitations in the programme were principally that, during the collection and curation of the cohorts of patients with RCC and RT, the pace of discovery of new biomarkers in commercial and non-commercial research was slower than anticipated and so conclusive evaluations using the cohorts are few; however, access to the cohorts will be sustained for future new biomarkers. The ELUCIDATE trial was slow to start and recruit to, with a late surge of recruitment, and so final conclusions about the impact of the ELF test on long-term outcomes await further follow-up. The findings from the three workstreams were used to synthesise a strategy and framework for future biomarker evaluations incorporating innovations in study design, health economics and health informatics.

Trial registration

Current Controlled Trials ISRCTN74815110, UKCRN ID 9954 and UKCRN ID 11930.

Funding

This project was funded by the NIHR Programme Grants for Applied Research programme and will be published in full inProgramme Grants for Applied Research; Vol. 6, No. 3. See the NIHR Journals Library website for further project information.

Mortality in Elderly Waiting-List Patients Versus Age-Matched Kidney Transplant Recipients: Where is the Risk?

The number of elderly patients on the waiting list (WL) for kidney transplantation (KT) has risen significantly in recent years. Because KT offers a better survival than dialysis therapy, even in the elderly, candidates for KT should be selected carefully, particularly in older waitlisted patients. Identification of risk factors for death in WL patients and prediction of both perioperative risk and long-term post-transplant mortality are crucial for the proper allocation of organs and the clinical management of these patients in order to decrease mortality, both while on the WL and after KT. In this review, we examine the clinical results in studies concerning: a) risk factors for mortality in WL patients and KT recipients; 2) the benefits and risks of performing KT in the elderly, comparing survival between patients on the WL and KT recipients; and 3) clinical tools that should be used to assess the perioperative risk of mortality and predict long-term post-transplant survival. The acknowledgment of these concerns could contribute to better management of high-risk patients and prophylactic interventions to prolong survival in this particular population, provided a higher mortality is assumed.

Hypothermic machine perfusion in kidney transplantation

PURPOSE OF REVIEW

This article summarizes novel developments in hypothermic machine perfusion (HMP) as an organ preservation modality for kidneys recovered from deceased donors.

RECENT FINDINGS

HMP has undergone a renaissance in recent years. This renewed interest has arisen parallel to a shift in paradigms; not only optimal preservation of an often marginal quality graft is required, but also improved graft function and tools to predict the latter are expected from HMP. The focus of attention in this field is currently drawn to the protection of endothelial integrity by means of additives to the perfusion solution, improvement of the HMP solution, choice of temperature, duration of perfusion, and machine settings. HMP may offer the opportunity to assess aspects of graft viability before transplantation, which can potentially aid preselection of grafts based on characteristics such as perfusate biomarkers, as well as measurement of machine perfusion dynamics parameters.

SUMMARY

HMP has proven to be beneficial as a kidney preservation method for all types of renal grafts, most notably those retrieved from extended criteria donors. Large numbers of variables during HMP, such as duration, machine settings and additives to the perfusion solution are currently being investigated to improve renal function and graft survival. In addition, the search for biomarkers has become a focus of attention to predict graft function posttransplant.

A double-blind randomised controlled investigation into the efficacy of Mirococept (APT070) for preventing ischaemia reperfusion injury in the kidney allograft (EMPIRIKAL): study protocol for a randomised controlled trial

Background

Delayed graft function (DGF) is traditionally defined as the requirement for dialysis during the first week after transplantation. DGF is a common complication of renal transplantation, and it negatively affects short- and long-term graft outcomes. Ischaemia reperfusion injury (IRI) is a prime contributor to the development of DGF. It is well established that complement system activation plays a pivotal role in the pathogenesis of IRI. Mirococept is a highly effective complement inhibitor that can be administered ex vivo to the donor kidney just before transplantation. Preclinical and clinical evidence suggests that Mirococept inhibits inflammatory responses that follow IRI. The EMPIRIKAL trial (REC 12/LO/1334) aims to evaluate the efficacy of Mirococept in reducing the incidence of DGF in cadaveric renal transplantation.

Methods/design

EMPIRIKAL is a multicentre double-blind randomised case-control trial designed to test the superiority of Mirococept in the prevention of DGF in cadaveric renal allografts, as compared to standard cold perfusion fluid (Soltran®). Patients will be randomised to Mirococept or placebo (Pbo) and will be enrolled in cohorts of N = 80 with a maximum number of 7 cohorts. The first cohort will be randomised to 10 mg of Mirococept or Pbo. After the completion of each cohort, an interim analysis will be carried out in order to evaluate the dose allocation for the next cohort (possible doses: 5–25 mg). Immunosuppression therapy, antibiotic and antiviral prophylaxis will be administered as per local centre protocols. The enrolment will take approximately 24 months, and patients will be followed for 12 months. The primary endpoint is DGF, defined as the requirement for dialysis during the first week after transplantation. Secondary endpoints include duration of DGF, functional DGF, renal function at 12 months, acute rejection episodes at 6 and 12 months, primary non-function and time of hospital stay on first admission and in the first year following transplant. Safety evaluation will include the monitoring of laboratory data and the recording of all adverse events.

Discussion

The EMPIRIKAL trial is the first study to evaluate the efficacy of an ex vivo administered complement inhibitor (Mirococept) in preventing DGF in cadaveric human renal transplantation. Mirococept has a unique ‘cytotopic’ property that permits its retention in the organ microvasculature.

Trial registration

ISRCTN registry, ISRCTN49958194. Registered on 3 August 2012.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-1972-x) contains supplementary material, which is available to authorized users.

Strategies for an Expanded Use of Kidneys From Elderly Donors

The old-for-old allocation policy used for kidney transplantation (KT) has confirmed the survival benefit compared to remaining listed on dialysis. Shortage of standard donors has stimulated the development of strategies aimed to expand acceptance criteria, particularly of kidneys from elderly donors. We have systematically reviewed the literature on those different strategies. In addition to the review of outcomes of expanded criteria donor or advanced age kidneys, we assessed the value of the Kidney Donor Profile Index policy, preimplantation biopsy, dual KT, machine perfusion and special immunosuppressive protocols. Survival and functional outcomes achieved with expanded criteria donor, high Kidney Donor Profile Index or advanced age kidneys are poorer than those with standard ones. Outcomes using advanced age brain-dead or cardiac-dead donor kidneys are similar. Preimplantation biopsies and related scores have been useful to predict function, but their applicability to transplant or refuse a kidney graft has probably been overestimated. Machine perfusion techniques have decreased delayed graft function and could improve graft survival. Investing 2 kidneys in 1 recipient does not make sense when a single KT would be enough, particularly in elderly recipients. Tailored immunosuppression when transplanting an old kidney may be useful, but no formal trials are available.Old donors constitute an enormous source of useful kidneys, but their retrieval in many countries is infrequent. The assumption of limited but precious functional expectancy for an old kidney and substantial reduction of discard rates should be generalized to mitigate these limitations.

Inadequate Antioxidative Responses in Kidneys of Brain-Dead Rats

BACKGROUND

Brain death (BD)-related lipid peroxidation, measured as serum malondialdehyde (MDA) levels, correlates with delayed graft function in renal transplant recipients. How BD affects lipid peroxidation is not known. The extent of BD-induced organ damage is influenced by the speed at which intracranial pressure increases. To determine possible underlying causes of lipid peroxidation, we investigated the renal redox balance by assessing oxidative and antioxidative processes in kidneys of brain-dead rats after fast and slow BD induction.

METHODS

Brain death was induced in 64 ventilated male Fisher rats by inflating a 4.0F Fogarty catheter in the epidural space. Fast and slow inductions were achieved by an inflation speed of 0.45 and 0.015 mL/min, respectively, until BD confirmation. Healthy non-brain-dead rats served as reference values. Brain-dead rats were monitored for 0.5, 1, 2, or 4 hours, after which organs and blood were collected.

RESULTS

Increased MDA levels became evident at 2 hours of slow BD induction at which increased superoxide levels, decreased glutathione peroxidase (GPx) activity, decreased glutathione levels, increased inducible nitric oxide synthase and heme-oxygenase 1 expression, and increased plasma creatinine levels were evident. At 4 hours after slow BD induction, superoxide, MDA, and plasma creatinine levels increased further, whereas GPx activity remained decreased. Increased MDA and plasma creatinine levels also became evident after 4 hours fast BD induction.

CONCLUSION

Brain death leads to increased superoxide production, decreased GPx activity, decreased glutathione levels, increased inducible nitric oxide synthase and heme-oxygenase 1 expression, and increased MDA and plasma creatinine levels. These effects were more pronounced after slow BD induction. Modulation of these processes could lead to decreased incidence of delayed graft function.

Donation and Transplantation of Kidneys Harvested From Deceased Donors Over the Age of 60 Years in the Upper Silesia Region

BACKGROUND

Population aging and shortage of organs for transplantation result in increasing numbers of kidneys retrieved from elderly donors. The aim of this study was to analyze donation of kidneys from donors after brain death (DBD) over the age of 60 years (≥60), comorbidities that affect decisions on retrieval, and early results of kidney transplantation.

METHODS

Ninety-six potential DBD ≥60 and 309 aged 40-59 years (40-59) reported in Upper Silesia, Poland, from 2004 to 2013 were enrolled in the study.

RESULTS

DBD >60 presented a higher rate of coexisting hypertension (53% vs 34%), limb ischemia (10% vs 1%), and past stroke (6% vs 1%) compared with DBD 40-59 (P < .05), but no differences were observed in serum creatinine concentration (85 vs 84 μmol/L), coexisting coronary disease (14% vs 6%), or diabetes (10% vs 4%). The decision of withdrawal from retrieval was more frequent in DBD ≥60 (16% vs 7%; P < .05). Twelve months after kidney transplantation, serum creatinine concentration was higher in recipients of kidneys from DBD ≥60 compared with DBD 40-59 (169 vs 138 μmol/L; P < .001). The survivals of recipients (93% vs 95%) and kidney grafts (90% vs 93%) as well as rates of proteinuria >1.0 g/24 h (6% vs 2%) did not differ between the groups.

CONCLUSIONS

A higher rate of comorbidities in potential kidney DBD ≥60 results in a lower retrieval rate in these donors. The function of kidneys harvested from DBD ≥60 12 months after transplantation is worse than those from DBD 40-59, but still acceptable.

An Improved Classification of Kidney Function Recovery Using Estimated Glomerular Filtration Rate Slope Post-transplantation

BACKGROUND

The impact of renal function recovery on graft survival was examined using estimated glomerular filtration rate (eGFR) slope after kidney transplantation (GAP classification); this was compared to the conventional classification of immediate graft function (IGF), slow graft function (SGF), and delayed graft function (DGF).

MATERIALS AND METHODS

Overall, 541 cases of cadaveric renal transplants were reviewed from a prospective transplant database. eGFR and its slope were measured using the harmonic mean over the first week post-transplantation. Next, 495 kidney transplant recipients from an independent institution were assessed to determine the prognostic value of graft function based on the eGFR slope.

RESULTS

The main discrimination of eGFR slopes occurred within the first 7 days. Three groups in the GAP classification (Good graft function, Average graft function, Poor graft function) were defined based on eGFR slope tertiles: good graft function (GGF), average graft function (AGF), and poor graft function (PGF) were defined based on the ΔCrCL per day over the first 7 days: <1 mL/min, 1-4 mL/min, and >4 mL/min, respectively. When applied to the validation cohort, the 5-year graft failure was 20% for the PGF group, 4% for the AGF group, and 3% for the GGF group. Multivariable Cox regression analysis demonstrated better prediction of long-term graft function with the new classification (C statistic 0.49 [old)] vs 0.61 [new]).

CONCLUSION

The new GAP criteria were better at predicting long-term graft survival and renal function compared to the conventional classification system, and deserve further consideration in future studies.

The Kidney Transplant Morbidity Index (KTMI): A Simple Prognostic Tool to Help Determine Outcome Risk in Kidney Transplant Candidates

Background

The Kidney Transplant Morbidity Index (KTMI) is a novel prognostic morbidity index to help determine the impact that pretransplant comorbid conditions have on transplant outcome.

Objective

To use national data to validate the KTMI.

Design

Retrospective analysis of the Organ Procurement and Transplant Network/United Network for Organ Sharing database.

Setting and Participants

The study sample consisted of 100 261 adult patients who received a kidney transplant between 2000 and 2008.

Main Outcome Measure

Kaplan-Meier survival curves were used to demonstrate 3-year graft and patient survival for each KTMI score. Cox proportional hazards regression models were created to determine hazards for 3-year graft failure and patient mortality for each KTMI score.

Results

A sequential decrease in graft survival (0 = 91.2%, 1 = 88.2%, 2 = 85.4%, 3 = 81.7%, 4 = 77.8%, 5 = 74.0%, 6 = 69.8%, and ≥7 = 68.7) and patient survival (0 = 98.2%, 1 = 96.6%, 2 = 93.7%, 3 = 89.7%, 4 = 84.8%, 5 = 80.8%, 6 = 76.0%, and ≥7 = 74.7%) is seen as KTMI scores increase. The differences in graft and patient survival between KTMI scores are all significant ( P < .001) except between 6 and ≥7. Multivariate regression analysis reveals that KTMI is an independent predictor of higher graft failure and patient mortality rates and that risk increases as KTMI scores increase.

Conclusion

The KTMI strongly predicts graft and patient survival by using pretransplant comorbid conditions; therefore, this easy-to-use tool can aid in determining outcome risk and transplant candidacy before listing, particularly in candidates with multiple comorbid conditions.

Immunologic prognostic factors of renal allograft survival

INTRODUCTION

Successful outcome of renal transplantation depends on various factors, of which immunologic is one of the most important. Accumulated experience of a single center, with the same surgical and immunological team contributes significantly to safe conclusions. Purpose of this study was the evaluation of potential factors, in particular immunologic, that influence renal allograft survival.

PATIENTS AND METHODS

During the period 1991-2013, 20,784 surgical operations have been performed in our Department of Surgery - Transplant Unit, of which 575 were renal transplantations. We examined donor and recipient demographic factors, immunologic characteristics along with patient and graft survival.

RESULTS

Renal allograft was retrieved from living-related donor in 103 cases and in 472 from cadaveric donor. Donor age was 46.7 ± 18.5 years old and 49.9% (287) were male. Recipient age was 48 ± 12.3 years old and 402 were male. HLA histocompatibility was carefully matched resulting in 85.5% renal transplants with 2-4 HLA mismatches and 93.8% renal transplants with at least one HLA-DR. Renal graft survival the first, fifth and tenth year was 89%, 76%, and 67% and patient survival was respectively 95%, 89% and 83%. Statistical analysis revealed that only donor age influenced renal graft survival (P < .05). HLA mismatches were not correlated with graft survival (log rank P = .495), but identification of panel reactive antibodies (PRA) class I and class II post transplantation had a statistically significant impact on long term renal graft survival (log rank P < .001 and P = .021, accordingly).

CONCLUSIONS

Analysis of potential prognostic factor showed that only donor age was correlated with allograft survival. Development of PRA following renal transplantation influenced long term graft survival. Good HLA matching with at least one HLA DR resulted in excellent graft and patient survival.

Mechanisms and consequences of injury and repair in older organ transplants

Donor organ scarcity remains a significant clinical challenge in transplantation. Older organs, increasingly utilized to meet the growing demand for donor organs, have been linked to inferior transplant outcomes. Susceptibility to organ injury, reduced repair capacity, and increased immunogenicity are interrelated and impacted by physiological and pathological aging processes. Insights into the underlying mechanisms are needed to develop age-specific interventional strategies with regards to organ preservation, immunosuppression, and allocation. In this overview, we summarize current knowledge of injury and repair mechanisms and the effects of aging relevant to transplantation.

Optimizing utilization of kidneys from deceased donors over 60 years: five-year outcomes after implementation of a combined clinical and histological allocation algorithm

This 5 year observational multicentre study conducted in the Nord Italian Transplant programme area evaluated outcomes in patients receiving kidneys from donors over 60 years allocated according to a combined clinical and histological algorithm. Low-risk donors 60-69 years without risk factors were allocated to single kidney transplant (LR-SKT) based on clinical criteria. Biopsy was performed in donors over 70 years or 60-69 years with risk factors, allocated to Single (HR-SKT) or Dual kidney transplant (HR-DKT) according to the severity of histological damage. Forty HR-DKTs, 41 HR-SKTs and 234 LR-SKTs were evaluated. Baseline differences generally reflected stratification and allocation criteria. Patient and graft (death censored) survival were 90% and 92% for HR-DKT, 85% and 89% for HR-SKT, 88% and 87% for LR-SKT. The algorithm appeared user-friendly in daily practice and was safe and efficient, as demonstrated by satisfactory outcomes in all groups at 5 years. Clinical criteria performed well in low-risk donors. The excellent outcomes observed in DKTs call for fine-tuning of cut-off scores for allocation to DKT or SKT in high-risk patients.

Update on the long-term complications of renal transplantation

INTRODUCTION

Powerful immunosuppressive regimens have reduced rejection risk, leading to an expanding cohort of long-term kidney transplant recipients who are likely to encounter practitioners in other specialties.

SOURCES OF DATA

Key review papers and primary literature identified through searches of PubMed, Google Scholar and Medline.

AREAS OF AGREEMENT

Death from cardiovascular disease and malignancy remain the chief causes of transplant loss. Risk factors and phenotypes for these differ from the general population.

AREAS OF CONTROVERSY

Many guidelines for renal transplant recipients are based on extrapolation from studies on non-transplant cohorts and may not be appropriate. Emerging studies demonstrate that established interventions in the general population are less efficacious in transplant recipients.

GROWING POINTS

The influence of immunosuppression on the development of complications.

AREAS TIMELY FOR DEVELOPING RESEARCH

Markers to guide individualized optimal immunosuppression and predict the development of complications would allow for targeted early intervention.

Lack of impact of donor age on patient survival for renal transplant recipients ≥60years

There has been an increase in the number of older patients on the transplant waiting list and acceptance of older donor kidneys. Although kidneys from older donors have been associated with poorer graft outcomes, whether there is a differential impact of donor age on outcomes in older recipients remains unclear. The aim of this study was to evaluate the effect of donor age on graft and patient survival in renal transplant (RT) recipients ≥60years. Using the Australia and New Zealand Dialysis and Transplant Registry, outcomes of 1,037 RT recipients ≥60years between 1995 and 2009 were analyzed. Donor age groups were categorized into 0-20, >20-40, >40-60, and >60years. Compared with recipients receiving donor kidneys >60years, those receiving donor kidneys >20-40years had lower risk of acute rejection (odds ratio 0.46, 95% CI 0.27, 0.79; P<0.01) and death-censored graft failure (HR 0.37, 95% CI 0.19, 0.72; P<0.01). There was no association between donor age groups and death. With a corresponding growth in the availability of older donor kidneys and the observed lack of association between donor age and patient survival in RT recipients ≥60years, preferential allocation of older donor kidneys to RT recipients ≥60years may not disadvantage the life expectancy of these patients.

Age is an important predictor of kidney transplantation outcome

BACKGROUND

Donor and recipient age may have an impact on the renal transplant outcome. Kidney transplantation from older donors may result in a worse outcome, and the survival benefit of kidney transplantation compared with dialysis may be reduced. The aim of this study was to evaluate the impact of donor and recipient age on kidney transplant outcome.

MATERIALS AND METHODS

Two hundred and twenty-three recipients of kidney transplants performed at our institution between 2002 and 2007 were analysed. The role of donor and recipient age matching on survival rate were investigated performing the Kaplan-Meier survival time analysis by decades, considering the donor's age of 60 and 70 years. The Cox proportional hazard uni- and multivariate regressions were also performed. Finally, Kaplan-Meier survival time analysis was performed to assess survival rates of patients transplanted stratified by donor age compared with wait-listed renal transplant candidates.

RESULTS

Elderly recipients had a significant lower graft and patient survival as well as a significantly higher risk of graft loss and patient death. Recipients younger and older than 65 years of age were at higher risk of graft loss if they received grafts from donors>65 years [hazard ratio (HR)=2.59, 95% confidence interval (CI): 1.12-6 and HR=5.65, 95% CI: 2.31-13.79, respectively]. Elderly recipients displayed a worse survival compared with transplant candidates on the waiting list.

CONCLUSIONS

Age is an important predictor of kidney transplantation outcome. Kidney transplantation does not offer a significant survival benefit in the intermediate term, compared to the waiting list, to elderly recipients transplanted with grafts from older donors. However, it cannot be excluded that it is still possible that there is a long-term benefit of transplantation over dialysis in this group of patients.

Predicting the outcome of renal transplantation

OBJECTIVE

Renal transplantation has dramatically improved the survival rate of hemodialysis patients. However, with a growing proportion of marginal organs and improved immunosuppression, it is necessary to verify that the established allocation system, mostly based on human leukocyte antigen matching, still meets today's needs. The authors turn to machine-learning techniques to predict, from donor-recipient data, the estimated glomerular filtration rate (eGFR) of the recipient 1 year after transplantation.

DESIGN

The patient's eGFR was predicted using donor-recipient characteristics available at the time of transplantation. Donors' data were obtained from Eurotransplant's database, while recipients' details were retrieved from Charité Campus Virchow-Klinikum's database. A total of 707 renal transplantations from cadaveric donors were included.

MEASUREMENTS

Two separate datasets were created, taking features with <10% missing values for one and <50% missing values for the other. Four established regressors were run on both datasets, with and without feature selection.

RESULTS

The authors obtained a Pearson correlation coefficient between predicted and real eGFR (COR) of 0.48. The best model for the dataset was a Gaussian support vector machine with recursive feature elimination on the more inclusive dataset. All results are available at http://transplant.molgen.mpg.de/.

LIMITATIONS

For now, missing values in the data must be predicted and filled in. The performance is not as high as hoped, but the dataset seems to be the main cause.

CONCLUSIONS

Predicting the outcome is possible with the dataset at hand (COR=0.48). Valuable features include age and creatinine levels of the donor, as well as sex and weight of the recipient.

A review of utility-based allocation strategies to maximize graft years of deceased donor kidneys

With the continuing shortage of deceased donor kidneys coupled with a growing number of older potential recipients, there has been a greater acceptance of using older donor kidneys, including increased utility of expanded criteria donor (ECD) kidneys. In this review, we will look at the impact of using ECD kidneys on graft and patient survival, and to identify modifiable factors that may improve transplant outcomes in recipients receiving ECD kidneys. In addition, we will discuss whether the implementation of utility-based allocation strategies to maximize graft outcomes is an appropriate way forward to provide a better balance between utility and equity in the distribution of deceased donor kidneys.

Tuberculosis following kidney transplantation: clinical features and outcome. A French multicentre experience in the last 20 years

BACKGROUND

Kidney transplant recipients are at high risk of opportunistic infection. The aims of this study were to describe the epidemiology, clinical features and prognosis of Tuberculosis (TB) in kidney transplant recipients.

METHODS

Retrospective observational study conducted in 14 French transplant centres involving all cases of TB that occurred in kidney transplant recipients between 1986 and 2006.

RESULTS

Among the 16146 kidney transplantations performed during the study period, 74 (0.45%) developed TB. The country of birth was a highly endemic area for TB in 20 (40.8%) patients. Time from kidney transplantation to TB was 10 months (4-27). Extrapulmonary and disseminated TB accounted for 33 (67.4%) cases. The most common symptoms were fever (71.7%), weight loss (41.3%) and asthenia (39.1%). Coexisting infections were diagnosed in 11 (22.4%) patients. Microbial sensitivity tests revealed no case of multidrug-resistant TB. Haemophagocytic syndrome associated with TB was diagnosed in 5 (10.2%) cases with 60% of mortality (P = 0.0005). Median length of antituberculous therapy was 12 (9.5-12) months. Immunosuppressive therapy was reduced in 22 (44.9%) patients without adverse consequence on the graft. Overall, hospital mortality was 6.1% and 1-year graft survival was 97%.

CONCLUSIONS

Kidney transplantation increases the risk of TB, with a high rate of extrapulmonary disease. Symptoms of infection are often attenuated, leading to delayed diagnosis. Overall prognosis is good but haemophagocytic syndrome is associated with high mortality. Country of birth might be taken into account in the decision of post-transplantation treatment of latent TB.

Acute respiratory failure in kidney transplant recipients: a multicenter study

INTRODUCTION

Data on pulmonary complications in renal transplant recipients are scarce. The aim of this study was to evaluate acute respiratory failure (ARF) in renal transplant recipients.

METHODS

We conducted a retrospective observational study in nine transplant centers of consecutive kidney transplant recipients admitted to the intensive care unit (ICU) for ARF from 2000 to 2008.

RESULTS

Of 6,819 kidney transplant recipients, 452 (6.6%) required ICU admission, including 200 admitted for ARF. Fifteen (7.5%) of these patients had combined kidney-pancreas transplantations. The most common causes of ARF were bacterial pneumonia (35.5%), cardiogenic pulmonary edema (24.5%) and extrapulmonary acute respiratory distress syndrome (ARDS) (15.5%). Pneumocystis pneumonia occurred in 11.5% of patients. Mechanical ventilation was used in 93 patients (46.5%), vasopressors were used in 82 patients (41%) and dialysis was administered in 104 patients (52%). Both the in-hospital and 90-day mortality rates were 22.5%. Among the 155 day 90 survivors, 115 patients (74.2%) were dialysis-free, including 75 patients (65.2%) who recovered prior renal function. Factors independently associated with in-hospital mortality were shock at admission (odds ratio (OR) 8.70, 95% confidence interval (95% CI) 3.25 to 23.29), opportunistic fungal infection (OR 7.08, 95% CI 2.32 to 21.60) and bacterial infection (OR 2.53, 95% CI 1.07 to 5.96). Five factors were independently associated with day 90 dialysis-free survival: renal Sequential Organ Failure Assessment (SOFA) score on day 1 (OR 0.68/SOFA point, 95% CI 0.52 to 0.88), bacterial infection (OR 0.43, 95% CI 0.21 to 0.90), three or four quadrants involved on chest X-ray (OR 0.44, 95% CI 0.21 to 0.91), time from hospital to ICU admission (OR 0.98/day, 95% CI 0.95 to 0.99) and oxygen flow at admission (OR 0.93/liter, 95% CI 0.86 to 0.99).

CONCLUSIONS

In kidney transplant recipients, ARF is associated with high mortality and graft loss rates. Increased Pneumocystis and bacterial prophylaxis might improve these outcomes. Early ICU admission might prevent graft loss.

Improving distribution efficiency of hard-to-place deceased donor kidneys: Predicting probability of discard or delay

We recently showed that DonorNet 2007 has reduced the efficiency of kidney distribution in the United States, particularly for those with prolonged cold ischemia time (CIT), by requiring systematic allocation of all kidneys regardless of quality. Reliable early identification of those most likely to be discarded or significantly delayed would enable assigning them to alternate, more efficient distribution strategies. Based on 39 035 adult kidneys recovered for possible transplantation between 2005 and 2008, we created a regression model that reliably (AUC 0.83) quantified the probability that a given kidney was either discarded or delayed beyond 36 h of CIT (Probability of Discard/Delay, PODD). We then analyzed two PODD cutoffs: a permissive cutoff that successfully flagged over half of those kidneys that were discarded/delayed, while only flagging 7% of kidneys that were not eventually discarded/delayed, and a more stringent cutoff that erroneously flagged only 3% but also correctly identified only 34%. Kidney transplants with high PODD were clustered in a minority of centers. Modifications of the kidney distribution system to more efficiently direct organs with high PODD to the centers that actually use them may result in reduced CIT and fewer discards.