Increased kidney transplantation utilizing expanded criteria deceased organ donors with results comparable to standard criteria donor transplant

Diagnostic and Prognostic Value of Machine Perfusion Biomarkers in Kidney Graft Evaluation

BACKGROUND

With the rising prevalence of end-stage kidney disease, the use of expanded criteria donor allografts, seen as essential for meeting organ demand, still proves challenging due to their higher risk of graft loss, delayed function, and rejection. Machine perfusion, a technique in preserving allografts, offers improved allograft outcomes compared to static cold storage while allowing for the noninvasive measurement of kidney injury biomarkers in the perfusate solution. This offers an objective method to assess graft function at various preservation stages.

MATERIALS AND METHODS

We conducted a narrative review of the databases PubMed and Scopus, including studies written in the English language and published after 2010.

RESULTS

In this narrative review, we identified biomarkers, like 4-hydroxyproline, taurine, and glutathione transferase, as predictive markers of delayed graft function. Additionally, biomarkers, like extracellular histone h3, vascular cell adhesion protein, and matrix metalloprotease protein, have shown correlation with decreased graft function, although their predictive ability remains inconclusive.

DISCUSSION

The review outlines various suggestions for potential areas of research focus to enhance future expanded criteria donor allograft utilization. However, limitations exist, including the absence of a singular reliable biomarker and the challenges of validating biomarker effectiveness across diverse outcomes.

Energy Metabolism and Metformin: Effects on Ischemia-Reperfusion Injury in Kidney Transplantation

Metformin (MTF) is the only biguanide included in the World Health Organization's list of essential medicines; representing a widespread drug in the management of diabetes mellitus. With its accessibility and affordability being one of its biggest assets, it has become the target of interest for many trying to find alternative treatments for varied pathologies. Over time, an increasing body of evidence has shown additional roles of MTF, with unexpected interactions of benefit in other diseases. Metformin (MTF) holds significant promise in mitigating ischemia-reperfusion injury (IRI), particularly in the realm of organ transplantation. As acceptance criteria for organ transplants expand, IRI during the preservation phase remain a major concern within the transplant community, prompting a keen interest in MTF's effects. Emerging evidence suggests that administering MTF during reperfusion may activate the reperfusion injury salvage kinase (RISK) pathway. This pathway is pivotal in alleviating IRI in transplant recipients, potentially leading to improved outcomes such as reduced rates of organ rejection. This review aims to contextualize MTF historically, explore its current uses, pharmacokinetics, and pharmacodynamics, and link these aspects to the pathophysiology of IRI to illuminate its potential future role in transplantation. A comprehensive survey of the current literature highlights MTF's potential to recondition and protect against IRI by attenuating free radical damage, activating AMP-activated protein kinase to preserve cellular energy and promote repair, as well as directly reducing inflammation and enhancing microcirculation.

Non-Donors of Organs and Tissues Due to Medical Refusal in a Transplant Referral Service

BACKGROUND

Obtaining organs for transplants through a deceased donor occurs exclusively through donation. However, some open protocols with potential donors do not become effective donors due to medical refusal. Our aim was to identify the profile of non-donors of organs and tissues due to medical refusal in a state reference service for transplants.

METHODS

This is a cross-sectional study with retrospective data collection from medical records of patients who died and had a protocol opened to evaluate brain death and procurement of organs and tissues in 2019.

RESULTS

The sample consisted of 27 patients, the majority of whom were female, aged over 71 years, had primary education, and were married. The main causes of medical refusal were age above the recommended age and septicemia. Brain death was mostly confirmed within 12 hours, and the main cause of hospitalization was a vascular event.

CONCLUSIONS

Identifying the profile of non-donors due to medical refusal is necessary for services to identify possible misattributed medical contraindications and thus contribute to reducing the disproportion between supply and demand for organs and tissues for transplants.

Prevention of Delayed Graft Function in Kidney Transplant Recipients through a Continuous Infusion of the Prostaglandin Analogue Iloprost: A Single-Center Prospective Study

BACKGROUND

Delayed graft function (DGF) is common after kidney transplantation from deceased donors and may significantly affect post-transplant outcomes. This study aimed to evaluate whether an innovative approach, based on the administration of the intravenous prostaglandin analogue iloprost, could be beneficial in reducing the incidence of DGF occurring after kidney transplantation from deceased donors.

METHODS

This prospective, randomized (1:1), placebo-controlled study enrolled all consecutive patients who received a kidney transplant from a deceased donor from January 2000 to December 2012 and who were treated in the peri-transplant period with the prostaglandin analogue iloprost at 0.27 μg/min through an elastomeric pump (treatment group) or with a placebo (control group).

RESULTS

A total of 476 patients were included: DGF was reported in 172 (36.1%) patients in the entire cohort. The multivariate analysis showed that the donor's age > 70 years (OR 2.50, 95% confidence interval (CI): 1.40-3.05, p < 0.001), cold ischemia time > 24 h (OR 2.60, 95% CI: 1.50-4.51, p < 0.001), the donor's acute kidney injury (OR 2.71, 95% CI: 1.61-4.52, p = 0.021) and, above all, the recipient's arterial hypotension (OR 5.06, 95% CI: 2.52-10.1, p < 0.0001) were the strongest risk factors for developing post-transplant DGF. The incidence of DGF was 21.4% in the treatment group and 50.9% in the control group (p < 0.001). Interestingly, among patients who developed DGF, those who received iloprost had a shorter duration of post-transplant DGF (10.5 ± 8.3 vs. 13.4 ± 6.7, days, p = 0.016).

CONCLUSIONS

This study showed that the use of a continuous infusion of iloprost could safely and effectively reduce the incidence of DGF in recipients of deceased-donor kidneys, allowing a better graft functionality as well as a better graft survival.

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.

Comparable kidney transplant outcomes in selected patients with a body mass index ≥ 40: A personalized medicine approach to recipient selection

INTRODUCTION

Many kidney transplant (KT) centers decline patients with a body mass index (BMI) ≥40 kg/m2 . This study's aim was to evaluate KT outcomes according to recipient BMI.

METHODS

We performed a single-center, retrospective review of adult KTs comparing BMI ≥40 patients (n = 84, BMI = 42 ± 2 kg/m2 ) to a matched BMI < 40 cohort (n = 84, BMI = 28 ± 5 kg/m2 ). Patients were matched for age, gender, race, diabetes, and donor type.

RESULTS

BMI ≥40 patients were on dialysis longer (5.2 ± 3.2 years vs. 4.1 ± 3.5 years, p = .03) and received lower kidney donor profile index (KDPI) kidneys (40 ± 25% vs. 53 ± 26%, p = .003). There were no significant differences in prevalence of delayed graft function, reoperations, readmissions, wound complications, patient survival, or renal function at 1 year. Long-term graft survival was higher for BMI ≥40 patients, including after adjusting for KDPI (BMI ≥40: aHR = 1.79, 95% CI = 1.09-2.9). BMI ≥40 patients had similar BMI change in the first year post-transplant (delta BMI: BMI ≥ 40 +.9 ± 3.3 vs. BMI < 40 +1.1 ± 3.2, p = .59).

CONCLUSIONS

Overall outcomes after KT were comparable in BMI ≥40 patients compared to a matched cohort with lower BMI with improved long-term graft survival in obese patients. BMI-based exclusion criteria for KT should be reexamined in favor of a more individualized approach.

Nonutilization of Kidneys From Donors After Circulatory Determinant of Death

Background.

The expansion of donation after circulatory determination of death (DCDD) programs and unmet demands for kidney transplantation indicate that there is a need to improve the efficiency and utilization of these organs.

Methods.

We studied all DCDD donors retrieved for kidney transplantation in Australia between 2014 and 2019 and determined the factors associated with nonutilization using least absolute shrinkage and selection operator and random forest models. Self-organizing maps were used to group these donors into clusters with similar characteristics and features associated with nonutilization were defined.

Results.

Of the 762 DCDD donors, 116 (15%) were not utilized for kidney transplantation. Of the 9 clusters derived from self-organizing map, 2 had the highest proportions of nonutilized kidneys. Factors for nonutilization (adjusted odds ratio [95% confidence interval], per SD increase) were duration from withdrawal of cardiorespiratory support till death (1.38 [1.16-1.64]), admission and terminal serum creatinine (1.43 [1.13-1.85]) and (1.41 [1.16-1.73]). Donor kidney function and duration of warm ischemia were the main factors for clinical decisions taken not to use kidneys from DCDD donors.

Conclusions.

Donor terminal kidney function and the duration of warm ischemia are the key factors for nonutilization of DCDD kidneys. Strategies to reduce the duration of warm ischemia and improve post-transplant recipient kidney function may reduce rates of nonutilization.

Dual kidney transplants from adult marginal donors: Review and perspective

The practice of dual kidney transplantation (DKT) from adult marginal deceased donors (MDDs) dates back to the mid-1990s with initial pioneering experiences reported by the Stanford and Maryland groups, at which time the primary indication was estimated insufficient nephron mass from older donors. Multiple subsequent studies of short and long-term success have been reported focusing on three major aspects of DKT: Identifying appropriate selection criteria and developing scoring systems based on pre- and post-donation factors; refining technical aspects; and analyzing mid-term outcomes. The number of adult DKTs performed in the United States has declined in the past decade and only about 60 are performed annually. For adult deceased donor kidneys meeting double allocation criteria, >60% are ultimately not transplanted. Deceased donors with limited renal functional capacity represent a large proportion of potential kidneys doomed to either discard or non-recovery. However, DKT may reduce organ discard and optimize the use of kidneys from MDDs. In an attempt to promote utilization of MDD kidneys, the United Network for Organ Sharing introduced new allocation guidelines pursuant to DKT in 2019. The purpose of this review is to chronicle the history of DKT and identify opportunities to improve utilization of MDD kidneys through DKT. This article is protected by copyright. All rights reserved.

Comparison of estimated glomerular filtration rate of marginal versus standard renal allograft: A prospective cohort study

Introduction:

The end-stage renal disease (ESRD) population is increasing worldwide and organ shortage is an important issue. The disparity between the availability of organs and waitlisted patients for transplants has forced many transplant centers across the world to use marginal kidney donors. We assess and compare postoperative estimated glomerular filtration rate (eGFR) in patients who received a graft from marginal renal donor (MRD) versus those who received a graft from standard renal donor (SRD).

Methods:

A total of 214 patients with ESRD underwent open live donor renal allografting from September 2015 to September 2017. Out of 214 donors, 165 (77.1%) were SRD and 49 (22.9%) were MRD. Post-transplant eGFR was calculated at 2 months for donors and at days 1, 3, 5, and 7 and month 1, 3, 6, and 12 for recipients.

Results:

There was no statistically significant difference in eGFR of recipients at preoperative and postoperative period between SRD and MRD groups. Although at 12 months of follow–up eGFR was relatively high in SRD group, it did not show any statistically significant difference. The recipient survival rate at 1-year follow-up was 98.2% in SRD and 100% in MRD group.

Conclusions:

Renal transplant recipients using MRDs have a comparable glomerular filtration rate to SRDs at the end of 1 year. Short-term outcomes in recipients receiving marginal renal grafts were similar when compared to the allograft from standard donors.

Impact of deceased donor with acute kidney injury on subsequent kidney transplant outcomes-an ANZDATA registry analysis

BACKGROUND

The need for kidney transplantation drives efforts to expand organ donation. The decision to accept organs from donors with acute kidney injury (AKI) can result in a clinical dilemma in the context of conflicting reports from published literature.

MATERIAL AND METHODS

This observational study included all deceased donor kidney transplants performed in Australia and New Zealand between 1997 and 2017. The association of donor-AKI, defined according to KDIGO criteria, with all-cause graft failure was evaluated by multivariable Cox regression. Secondary outcomes included death-censored graft failure, death, delayed graft function (DGF) and acute rejection.

RESULTS

The study included 10,101 recipients of kidneys from 5,774 deceased donors, of whom 1182 (12%) recipients received kidneys from 662 (11%) donors with AKI. There were 3,259 (32%) all-cause graft failures, which included 1,509 deaths with functioning graft. After adjustment for donor, recipient and transplant characteristics, donor AKI was not associated with all-cause graft failure (adjusted hazard ratio [HR] 1.11, 95% CI 0.99-1.26), death-censored graft failure (HR 1.09, 95% CI 0.92-1.28), death (HR 1.15, 95% CI 0.98-1.35) or graft failure when death was evaluated as a competing event (sub-distribution hazard ratio [sHR] 1.07, 95% CI 0.91-1.26). Donor AKI was not associated with acute rejection but was associated with DGF (adjusted odds ratio [OR] 2.27, 95% CI 1.92-2.68).

CONCLUSION

Donor AKI stage was not associated with any kidney transplant outcome, except DGF. Use of kidneys with AKI for transplantation appears to be justified.

Urological Complications in Kidney Transplant Recipients: Analysis of the Risk Factors and Impact on Transplant Outcomes in the Era of “Extended Criteria Donors”

Urological complications (UC) following kidney transplantation (KT) are associated with increased morbidity. The aim of this study is to evaluate the risk factors for UC in the era of “extended criteria donors” (ECD) and their impact on patient and graft survivals. A retrospective monocentric study of all patients undergoing KT from 2010 to 2019 with a follow-up ≥30 days was performed. Out of 459 patients (males: 296 (64.5%); age: 57 (19–77) years) enrolled, 228 (49.7%) received ECD organs, moreover, 166 (67.2%) grafts had a cold ischemia time ≥10 h. UCs were reported in 32 (7%) patients. In 21 (65.6%) cases UC occurred within 3 months post-KT and 24 (5.2%) were associated with early urinary tract infection (UTI). The overall 5 year patient and graft survival rates were 96.5% and 90.6%, respectively. UC decreased graft survival (UC-group: 75.0% vs. noUC-group: 91.8%, p < 0.001), especially if associated with early UTI (UC-group: 71.4% vs. noUC-group: 77.8%, p < 0.001). At multivariate analysis, early UTI after KT (OR: 9.975, 95%-IC: 2.934–33.909, p < 0.001) and delayed graft function (DGF) (OR: 3.844, 95%-IC: 1.328–11.131, p: 0.013) were significant risk factors for UC, while ECD graft did not increase the risk of post-transplant UC. ECD grafts are not associated with UC. DGF and early UTI post-KT increase the risks of UC and reduce graft survival in the long-term. Therefore, aggressive management of early post-transplant UTI and strategies to reduce DGF incidence, such as machine preservation, are essential to prevent UC after KT.

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.

Projecting the Number of Posttransplant Clinic Visits With a Rise in the Number of Kidney Transplants: A Case Study From Ontario, Canada

Background:

In Ontario, kidney transplants have risen by 4% annually in recent years. An understanding of how this will affect the future annual number of posttransplant follow-up visits informs how to organize and deliver care.

Objective:

We projected the required number of annual posttransplant follow-up nephrology visits to inform posttransplant care delivery.

Design:

Population-based retrospective cohort study.

Setting:

Linked databases from Ontario, Canada (population 14 million).

Patients:

Incident kidney transplant recipients from years 2008 to 2013.

Measurements:

Frequency, distance traveled, and current and projected visits for posttransplant follow-up.

Methods:

Assuming a graft survival of 13 years and using the mean number of posttransplant clinic visits in years 1, 2, and 3, we forecasted the number of clinic visits needed in the year 2027.

Results:

Using data from 2443 recipients, the mean (SD) number of clinic visits per recipient was 14.0 (9.2) in the first year after transplant, and 3.9 (6.2) and 3.0 (5.3) in the second and third year, respectively. If transplant rates rise by 4% per year until 2027, the estimated annual visits number will increase from 30 622 to 43 948. The median (25th, 75th percentile) distance between transplant center and patient’s home was 30 (13, 65) km. The median round-trip travel distance for these visits in the first year after transplantation was 603 km per recipient, and median driving cost was Can$344 (2017).

Limitations:

Regarding patient expense, limitations include that distances traveled were calculated orthodromically, and we did not account for patient cost of follow-up beyond that of vehicular travel. Regarding follow-up projections, limitations include the assumption that graft life span will not change, follow-up patterns do not differ between donor kidney type, and we did not survey stakeholders as to their preferred method of follow-up.

Conclusion:

We quantified the increase in posttransplant visits when regional annual rates of transplantation rise. Strategies recognizing the burden of these visits may enhance patient-centered care, as it is unclear how some patients manage costs, nor how the current health care system will manage the demand.

Expanded Criteria Donor Kidneys With Kidney Donor Profile Index ≤ 85%: Are We Doing Enough to Counsel Our Patients?

BACKGROUND

Kidneys at higher risk for allograft failure are defined by the Kidney Donor Profile Index (KDPI) > 85% in the current kidney allocation system (KAS), replacing the historical concept of expanded criteria donor (ECD) kidneys in the previous KAS. Discrepancies exist in the classification of "high-risk kidneys" between the 2 KAS. In the current KAS, only recipients of KDPI > 85% kidneys are counseled about the high risk of allograft failure and are required to sign a consent. In this study, we evaluated the outcomes and allocation of kidneys with discordant classification.

METHODS

Using the Scientific Registry of Transplant Recipients, kidneys transplanted between 01/2002 and 09/2016 were classified according to the old (standard criteria donor [SCD]/ECD) and current (KDPI) KAS. We then grouped them as concordant (KDPI ≤ 85% + SCD or KDPI > 85% + ECD) and discordant (KDPI ≤ 85% + ECD or KDPI > 85% + SCD) kidneys.

RESULTS

Approximately 11% of transplanted kidneys were discordant in classification. Among kidneys with KDPI ≤ 85%, ECD status conferred a 64% (95% CI: 56%-73%) higher risk of allograft failure compared to SCD status. However, SCD/ECD status was not associated with differential outcomes in KDPI > 85% kidneys. These ECD kidneys have KDPIs > 50% and have been transplanted across all estimated post-transplant survival (EPTS) deciles.

CONCLUSION

Adequate counseling about the risk and benefit of accepting ECD kidneys with KDPI ≤ 85% versus waiting on dialysis should be explored with the patients, especially those with lower EPTS.

Should we use kidneys from donors with acute kidney injury for renal transplantation?

The scarcity of donor organs for transplant results in long waiting times for kidney transplantation and low transplant rate worldwide. Utilization of kidneys from donors with acute kidney injury (AKI) is one of the strategies that has attracted attention recently. This article reviewed the outcomes of transplanted renal allografts from donors with acute kidney injury. Key findings about the transplant outcomes included a higher incidence of delayed graft function and primary non function, but respectable outcomes in the context of similar acute rejection rates, and graft function and graft survival. Against this background and with evidence of high mortality for patients remaining on waiting list of transplant, we advocate consideration of AKI donors for kidney transplantation.

Should Immunosuppression After Kidney Transplant Be Adjusted Based on Renal Resistance During Pretransplant Hypothermic Machine Perfusion?

BACKGROUND

The hypothermic machine perfusion reduces delayed graft function after kidney transplant and allows, to some extent, predicting early graft function. However, it is difficult to identify exact perfusion criteria with which to exclude kidneys from transplant or modify post-transplant care. The aim of this study was to analyze whether renal resistance during the fourth hour of hypothermic machine perfusion is useful in the prediction of graft survival and acute rejection.

PATIENTS AND METHODS

Data on pretransplant hypothermic machine perfusion parameters of 407 transplanted kidneys were available. Receiver operating characteristic curve analysis was performed to find an optimal cutoff value of ratio for predicting a higher risk class of considered group of patients. According to this, patients were divided into 2 groups: those who received kidneys with renal resistance lower than 0.19 mm Hg/mL/min (R1; n = 187) and those who received kidneys with renal resistance equal to or higher than 0.19 mm Hg/mL/min (R2; n = 220). Within R2, we additionally analyzed 2 subgroups: patients who received induction therapy (R2-Ind+; n = 124) and those who did not received induction therapy (R2-Ind-; n = 96).

RESULTS

Acute rejection in R1 within 1 month post transplant was 2-fold lower compared with R2 and was 6.4% vs 13.1% (P = .03), respectively. One-year graft survival was higher in R1 compared with R2 and was 94.6% vs 88.5% (P = .03), respectively. Acute rejection in the R2-Ind+ subgroup within 1 month post transplant was 2.46-fold lower compared with the R2-Ind- subgroup and was 8% vs 19.7% (P = .01), respectively.

CONCLUSION

Immunosuppression treatment after transplant should be adjusted to perfusion parameters.

Successful transplantation of kidneys from deceased donors with terminal acute kidney injury

BACKGROUND

There are many doubts with regards to accepting deceased kidneys with acute kidney injury (AKI) for transplantation.

PURPOSE

The aim of this study was to present the 5-years outcome of kidney transplantation cases where deceased donors developed AKI before organ procurement.

METHODS

Two hundred twenty-six deceased renal transplants were analyzed. Data regarding donors and recipients were collected. Terminal AKI was defined as terminal serum creatinine concentration higher than 1.99 mg/dL and 66 such cases were diagnosed. All kidney transplant recipients were followed for 60 months.

RESULTS

AKI group presented more episodes of delayed graft function (DGF) compared to the non-AKI group (56% vs 35%, p < .05). No differences were observed between the groups in the rate of acute rejection episodes, kidney function as well as patient and graft survival.

CONCLUSIONS

Transplants with AKI present more often DGF and comparable graft survival to transplants without AKI. Kidneys with AKI can be a valuable source of organs provided attentive selection and appropriate care of deceased donors.

A urinary microRNA panel that is an early predictive biomarker of delayed graft function following kidney transplantation

Predicting immediate and subsequent graft function is important in clinical decision-making around kidney transplantation, but is difficult using available approaches. Here we have evaluated urinary microRNAs as biomarkers in this context. Profiling of 377 microRNAs in the first urine passed post-transplantation identified 6 microRNAs, confirmed to be upregulated by RT-qPCR in an expanded cohort (miR-9, -10a, -21, -29a, -221, and -429, n = 33, P < 0.05 for each). Receiver operating characteristic analysis showed Area Under the Curve 0.94 for this panel. To establish whether this early signal was sustained, miR-21 was measured daily for 5 days post-transplant, and was consistently elevated in those developing Delayed Graft Function (n = 165 samples from 33 patients, p < 0.05). The biomarker panel was then evaluated in an independent cohort, sampled at varying times in the first week post-transplantation in a separate transplant center. When considered individually, all miRs in the panel showed a trend to increase or a significant increase in those developing delayed Graft Function (miR-9: P = 0.068, mIR-10a: P = 0.397, miR-21: P = 0.003, miR-29a: P = 0.019, miR-221: P = 0.1, and miR-429: P = 0.013, n = 47) with Area Under the Curve 0.75 for the panel. In conclusion, combined measurement of six microRNAs had predictive value for delayed graft function following kidney transplantation.

Older Donation After Circulatory Death Kidneys for Older Recipients: A Single-Center Experience

The number of older patients is increasing on the transplant waiting list. Donation after circulatory death (DCD) kidney transplantation has increased, but there remains hesitancy in use of older DCD organs. The aim of this study was to evaluate outcomes of directing older DCD donor kidneys into older recipients.

METHODS

Patients 60 years or older who received transplants from DCD donors 60 years or older, between February 2010 and January 2014, were identified from a prospectively maintained database.

RESULTS

Over a 4-year period, 88 patients 60 years or older received DCD kidney transplants from donors 60 years or older. Of these 44 (55%) were 60 to 69 years old and 40 (45%) were 70 years or older. Median follow up was 63 months. Patient survival was 95% and 79% at 1 and 5 years, respectively, with a survival in those 70 years and older (69%) compared with those aged 60 to 69 (88%) years (P = .01). Censored for death graft survival was 94% and 80% at 1 and 5 years, respectively. Median estimated glomerular filtration rate at 12 months and 36 months was 36 mL/min (range, 11-70 mL/min) and 39.5 mL/min (range, 11-77 mL/min), respectively.

CONCLUSIONS

Older DCD kidneys, when transplanted into older recipients, result in good patient and graft survival and an acceptable graft function, especially considering their age. This represents a good use of this organ resource.

Pre-transplant histology does not improve prediction of 5-year kidney allograft outcomes above and beyond clinical parameters

Pre-implant kidney biopsy is used to determine suitability of marginal donor kidneys for transplantation. However, there is limited data examining the utility of pre-implant histology in predicting medium term graft outcome. This retrospective study examined kidney transplants over a 10-year period at a single center to determine if pre-implant histology can identify cases of eGFR ≤35 ml/min/1.73m² at 5 year follow up beyond a clinical predictive logistic regression model. We also compared outcomes of dual kidney transplants with standard single kidney transplants. Of 1195 transplants, 171 received a pre-implant kidney biopsy and 15 were dual transplants. There was no significant difference in graft and patient survival rates. Median eGFR was lower in recipients of biopsied kidneys compared with standard kidney transplants (44 vs. 54 ml/min/1.73m², p < .001). Median eGFR of dual transplant and standard kidney transplants were similar (58 vs. 54 ml/min/1.73m², p = .64). Glomerular sclerosis (p = .05) and Karpinski Score (p = .03) were significant predictors of eGFR at 5-years in multivariate analysis but did not improve discrimination of eGFR ≤35 ml/min/1.73m² at 5-years beyond a clinical prediction model comprising donor age, donor hypertension and terminal donor creatinine (C-statistic 0.67 vs. 0.66; p = .647). Pre-implant histology did not improve prediction of medium-term graft outcomes beyond clinical predictors alone. Allograft function of dual transplant kidneys was similar to standard transplants, suggesting that there is scope to increase utilization of kidneys considered marginal based on histology.

Factors leading to the discard of deceased donor kidneys in the United States

The proportion of deceased donor kidneys procured for transplant but subsequently discarded has been growing steadily in the United States, but factors contributing to the rising discard rate remain unclear. To assess the reasons for and probability of organ discard we assembled a cohort of 212,305 deceased donor kidneys recovered for transplant from 2000-2015 in the SRTR registry that included 36,700 kidneys that were discarded. 'Biopsy Findings' (38.2%) was the most commonly reported reason for discard. The median Kidney Donor Risk Index of discarded kidneys was significantly higher than transplanted organs (1.78 vs 1.12), but a large overlap in the quality of discarded and transplanted kidneys was observed. Kidneys of donors who were older, female, Black, obese, diabetic, hypertensive or HCV-positive experienced a significantly increased odds of discard. Kidneys from donors with multiple unfavorable characteristics were more likely to be discarded, whereas unilaterally discarded kidneys had the most desirable donor characteristics and the recipients of their partner kidneys experienced a one-year death-censored graft survival rate over 90%. There was considerable geographic variation in the odds of discard across the United States, which further supports the notion that factors beyond organ quality contributed to kidney discard. Thus, while the discard of a small fraction of organs procured from donors may be inevitable, the discard of potentially transplantable kidneys needs to be avoided. This will require a better understanding of the factors contributing to organ discard in order to remove the disincentives to utilize less-than-ideal organs for transplantation.

Analysis of Distribution of Expanded- and Standard-Criteria Donors and Complications Among Polish Recipients by Kidney Donor Risk Index Value

INTRODUCTION

The approach toward transplanting kidneys from expanded-criteria donors (ECDs) in Poland is largely site-dependent. The Kidney Donor Risk Index (KDRI) allows for obtaining a more precise characteristic of ECDs and further stratification into "better" and "worse" quality grafts.

METHODS

Comparison of the incidence of delayed graft function (DGF) and biopsy-proven acute rejection (BPAR), median of hospitalization time and median of estimated glomerular filtration rate (eGFR) at 1 year after transplantation among kidney graft recipients (n = 468), divided by donor status (ECD/standard-criteria donor [SCD]) and KDRI value (I: 0.67-1.2, II: 1.21-1.6, III: 1.61-2.0, IV: 2.01-3.48).

RESULTS

ECD kidneys have been transplanted to 32.47% of recipients. There were no ECD recipients in KDRI compartment I, 16.55% in compartment II, 79.22% in compartment III, and 100% in IV. In KDRI compartment II, DGF was diagnosed in 34.9% of SCDs and 56% of ECDs (P = .003), BPAR occurred in 7.8% of SCDs and 16% of ECDs (P = .073), median hospital stay was 12 days for SCDs and ECDs (P = 1), and eGFR was 50.7 mL/min for SCDs and 49.4 mL/min for ECDs (P = .734). In KDRI compartment III, DGF was diagnosed in 43.8% of SCDs and 49.2% of ECDs (P = .139), BPAR occurred in 6.3% of SCDs and 31.7% of ECDs (P = .001), median hospital stay was 10 days for SCDs and 12 days for ECDs (P = .634), and eGFR was 49.5 mL/min for SCDs and 45.2 mL/min for ECDs (P = .382). Among ECD recipients, DGF was diagnosed in 56.0%, 49.2%, and 47.7% of patients for KDRI compartments II, III, and IV respectively (P = .776); BPAR occurred in 16% (compartment II), 31.7% (compartment III), and 23.1% (compartment IV) (P = .273); the median hospital stay was 12 days (compartment II), 12 days (compartment III), and 12.5 days (compartment IV) (P = 1); and eGFR was 49.5 mL/min (compartment II), 45.4 mL/min (compartment III), and 36.1 mL/min (compartment IV) (P = .002).

CONCLUSION

Assessment using both the ECD and KDRI systems allows for a more precise evaluation of prognosis and predicting complications among recipients.

Mesenchymal Stromal Cells as Anti-Inflammatory and Regenerative Mediators for Donor Kidneys During Normothermic Machine Perfusion

There is great demand for transplant kidneys for the treatment of end-stage kidney disease patients. To expand the donor pool, organs from older and comorbid brain death donors, so-called expanded criteria donors (ECD), as well as donation after circulatory death donors, are considered for transplantation. However, the quality of these organs may be inferior to standard donor organs. A major issue affecting graft function and survival is ischemia/reperfusion injury, which particularly affects kidneys from deceased donors. The development of hypothermic machine perfusion has been introduced in kidney transplantation as a preservation technique and has improved outcomes in ECD and marginal organs compared to static cold storage. Normothermic machine perfusion (NMP) is the most recent evolution of perfusion technology and allows assessment of the donor organ before transplantation. The possibility to control the content of the perfusion fluid offers opportunities for damage control and reparative therapies during machine perfusion. Mesenchymal stromal cells (MSC) have been demonstrated to possess potent regenerative properties via the release of paracrine effectors. The combination of NMP and MSC administration at the same time is a promising procedure in the field of transplantation. Therefore, the MePEP consortium has been created to study this novel modality of treatment in preparation for human trials. MePEP aims to assess the therapeutic effects of MSC administered ex vivo by NMP in the mechanisms of injury and repair in a porcine kidney autotransplantation model.

The Need for New Donor Stratification to Predict Graft Survival in Deceased Donor Kidney Transplantation

PURPOSE

The aim of this study was to determine whether stratification of deceased donors by the United Network for Organ Sharing (UNOS) criteria negatively impacts graft survival.

MATERIALS AND METHODS

We retrospectively reviewed deceased donor and recipient pretransplant variables of kidney transplantations that occurred between February 1995 and December 2009. We compared clinical outcomes between standard criteria donors (SCDs) and expanded criteria donors (ECDs).

RESULTS

The deceased donors consisted of 369 patients. A total of 494 transplant recipients were enrolled in this study. Mean age was 41.7±11.4 year (range 18-69) and 273 patients (55.4%) were male. Mean duration of follow-up was 8.8±4.9 years. The recipients from ECD kidneys were 63 patients (12.8%). The overall mean cold ischemia time was 5.7±3.2 hours. Estimated glomerular filtration rate at 1, 2, and 3 years after transplantation were significantly lower in ECD transplants (1 year, 62.2±17.6 vs. 51.0±16.4, p<0.001; 2 year, 62.2±17.6 vs. 51.0±16.4, p=0.001; 3 year, 60.9±23.5 vs. 54.1±18.7, p=0.047). In multivariate analysis, donor age (≥40 years) was an independent risk factor for graft failure. In Kaplan-Meier analyses, there was no significant difference in death-censored graft survival (Log rank test, p>0.05), although patient survival was lower in ECDs than SCDs (Log rank test, p=0.011).

CONCLUSION

Our data demonstrate that stratification by the UNOS criteria does not predict graft survival. In order to expand the donor pool, new criteria for standard/expanded donors need to be modified by regional differences.

Trends in brain-dead organ donor characteristics: a 13-year analysis

BACKGROUND

Driven by disease trends, such as obesity and metabolic syndrome, that are increasingly prevalent in the general population, we aimed to evaluate the comorbidities and attributes of the brain-dead organ donor population over time in a longitudinal study.

METHODS

We compared overall health and baseline attributes of organ donors between 2000-2005 and 2006-2012 using our prospective transplant database. Descriptive and comparative analyses of the 2 historical cohorts were performed.

RESULTS

A total of 1040 brain-dead organ donors were included in our analysis: 496 from the 2000-2005 period and 544 from the 2006-2012 period. Our analysis revealed that donors from the recent (2006-2012) period were more likely to have increased body mass index (26.4 ± 6.0 v. 25.0 ± 4.8, p = 0.003), smoking history (57.0% v. 27.2%, p < 0.001), coronary artery disease (14.3% v. 3.2%, p = 0.015) and dyslipidemia (19.1% v. 4.2%, p < 0.001), but less likely to have concurrent infection (1.1% v. 7.9%, p < 0.001) than those from the earlier period.

CONCLUSION

Our data suggest that the characteristics and comorbidities of brain-dead organ donors have somewhat deteriorated over the last decade. Further studies are needed to evaluate the impact of these health attributes on donated organ utilization and outcomes.

ECD kidney transplantation outcomes are improved when matching donors to recipients using a novel creatinine clearance match ratio (CCMR)

Improved outcomes have been associated with various methods of size matching between expanded criteria (ECD) donors and recipients. A novel method for improved functional based matching was developed utilizing manipulation of Cockcroft-Gault estimated creatinine clearances for donor and recipient. We hypothesized that optimal clearance-based matches would have superior outcomes for both immediate graft function and long-term graft survival. For the analysis, recipients of ECD kidneys in the Scientific Registry of Transplant Recipients (SRTR) transplanted between October 1, 1987 and August 31, 2011 were included. Univariate and multivariate analyses predicted the hazard ratio of graft failure and the odds ratio of requiring dialysis within the first week. A total of 25,640 ECD kidney transplants were analyzed. On multivariate analysis, higher creatinine clearance match ratio (CCMR) was associated with increased graft failure and odds of requiring dialysis within the first week (comparing highest ratio quintile versus lowest ratio quintile: HR 1.43, p < 0.001; OR 2.08, p < 0.001). This study suggests that ECD kidneys have improved outcomes when the recipient/donor CCMR is optimized.

Proposal of categorization of expanded criteria donors in renal transplantation

INTRODUCTION

Transplantation of renal allografts that have been procured from expanded criteria donors (ECD) have prevailed in an attempt to expand the donor pool. Even though ECD is an acceptable source of donors, the wide range of age along with the presence or not of risk factors necessitates further categorization. The aim of this study was to analyze the allograft and recipient survival of the ECD renal grafts and to propose an ECD categorization model.

PATIENTS AND METHODS

We reviewed the medical records of renal transplant recipients from January 2002 to July 2012, who received renal allografts from expanded and standard criteria donors (SCD) without risk factors such as hypertension, cerebrovascular disease or impaired renal function.

RESULTS

During the study period, 310 renal transplantations were performed in our Transplant Unit, of which 86 and 114 renal grafts were procured from ECD and SCD respectively. ECD renal graft survival the first, third and fifth year was 92%, 82% and 70% while respective recipient survival was 95%, 87% and 82%. Comparison with the control group of SCD showed that ECD renal graft survival after the third post-transplant year was significantly inferior (P < .0001). Donor age was a considerable prognostic factor of long-term renal graft function. Serum creatinine of ECD grafts was the first and third year 1.86 ± 0.6 mg/dL and 1.91 ± 0.8 mg/dL, respectively, showing significant difference to that of SCD grafts (P < .0001). Further categorization of ECD showed that renal allografts procured from donors above 60 years old without risk factors had better renal graft survival and function compared to grafts procured from donors aged 50-59 with 2 or 3 risk factors.

CONCLUSIONS

Renal transplantation from ECD offers acceptable graft survival rates, however they are inferior compared to renal grafts from optimal kidney donors. ECD kidney grafts have to be categorized, taking into consideration the independent risk factors.

Kidney transplantation outcomes from expanded criteria donors, standard criteria donors or living donors older than 60 years

OBJECTIVES

To evaluate outcomes in kidney allograft recipients from donors with expanded criteria (ECD) versus standard criteria (SCD) or living donors (LD) >60 years.

METHODS

We studied all patients who received a kidney between 2005 and 2011, focusing in recipients of kidneys from deceased ECD, SCD and LD >60 years. ECD was any deceased donor >60 years or >50 years with two of the following: hypertension (HTN), stroke as the cause of death, or serum creatinine >1.5 mg/dL. We recorded characteristics of the transplant procedure, patient, graft survival and renal function 1 year after transplantation and at the end of follow-up.

RESULTS

Six-hundred and five patients were transplanted between 2005 and 2011 in our department. There were 142 (25.1%) transplantations from ECD, 192 (33.98%) from SCD and 96 (16.99%) from LDs older than 60 years. In a mean follow-up time of 36.4 months, graft survival rates were similar for all groups. Calculated GFR was found statistically different between the ECD and SCD groups, but still satisfactory at first year, and at end of follow-up time. Comparison of the patients, who received transplants from ECD, even older than 70 years, and those from LD >60 years revealed equivalent renal function in short and long term.

CONCLUSIONS

Utilization of marginal kidneys effectively doubled our deceased transplant volume in the period 2005-2011. Patients' and graft survival were shown similar at the end of follow-up for all groups. Renal outcomes were shown equivalent between the ECD and LD >60 years groups, and although significantly lower between the ECD and the SCD group, were still very satisfactory.

Challenges of organ shortage for transplantation: solutions and opportunities

Organ shortage is the greatest challenge facing the field of organ transplantation today. A variety of approaches have been implemented to expand the organ donor pool including live donation, a national effort to expand deceased donor donation, split organ donation, paired donor exchange, national sharing models and greater utilization of expanded criteria donors. Increased public awareness, improved efficiency of the donation process, greater expectations for transplantation, expansion of the living donor pool and the development of standardized donor management protocols have led to unprecedented rates of organ procurement and transplantation. Although live donors and donation after brain death account for the majority of organ donors, in the recent years there has been a growing interest in donors who have severe and irreversible brain injuries but do not meet the criteria for brain death. If the physician and family agree that the patient has no chance of recovery to a meaningful life, life support can be discontinued and the patient can be allowed to progress to circulatory arrest and then still donate organs (donation after circulatory death). Increasing utilization of marginal organs has been advocated to address the organ shortage.

Feasibility of renal transplantation after unroofing of a large renal cyst in an expanded criteria donor

We present a case in which a deceased donor kidney with a large simple cyst was successfully unroofed and transplanted to a 61-year-old male. The donor was a 62-year-old male with a history of hypertension for 2 years; cerebral vascular accident was the cause of death. A large 8-cm cyst distorting the renal hilum was identified upon the procurement of the deceased donor kidney. Prior to transplantation, the large cyst was unroofed from the allograft; the frozen section confirmed a benign cyst and the transplant was performed. Postoperatively, the serum creatinine level was 1.4 mg/ml at 22-month follow-up and the patient was normotensive. Deceased donor kidneys with giant cysts distorting the renal hilum can be effectively transplanted.

Kidney, pancreas and liver allocation and distribution in the United States

Kidney transplant and liver transplant are the treatments of choice for patients with end-stage renal disease and end-stage liver disease, respectively. Pancreas transplant is most commonly performed along with kidney transplant in diabetic end-stage renal disease patients. Despite a steady increase in the numbers of kidney and liver transplants performed each year in the United States, a significant shortage of kidneys and livers available for transplant remains. Organ allocation is the process the Organ Procurement and Transplantation Network (OPTN) uses to determine which candidates are offered which deceased donor organs. OPTN is charged with ensuring the effectiveness, efficiency and equity of organ sharing in the national system of organ allocation. The policy has changed incrementally over time in efforts to optimize allocation to meet these often competing goals. This review describes the history, current status and future direction of policies regarding the allocation of abdominal organs for transplant, namely the kidney, liver and pancreas, in the United States.

Successful outcome of transplant of kidneys recovered from a brain-dead liver transplant recipient: case report

Few reports describing the use of organs donated by transplant recipients have been published. In this case report, kidneys procured from a brain-dead liver recipient were transplanted successfully. A 21-year-old man was referred for liver transplant after an overdose of acetaminophen. The patient's kidney function was initially normal, with proper urine production and normal kidney laboratory parameters. On the third day after admission, the patient's kidney laboratory parameters became elevated and hepatic encephalopathy requiring mechanical ventilation developed. An orthotopic liver transplant was performed the next day. The patient did not recover consciousness, and brain death was diagnosed on the third day after the liver transplant surgery. The maximum serum concentration of creatinine was 5.8 mg/dL (513 μmol/L) before kidney recovery, and urine production was normal. The kidneys were recovered with organ-perfusion support and were preserved by using machine perfusion. The kidneys were transplanted into 2 male recipients. Twelve months after transplant, the recipients remained in good health with satisfactory kidney function. This case demonstrates that transplanting kidneys recovered from liver transplant recipients is possible and beneficial, thus expanding the pool of potential donors.

Availability, utilization and outcomes of deceased diabetic donor kidneys; analysis based on the UNOS registry

The number of kidneys obtained from deceased diabetic donors available for transplantation has increased >eightfold increase in the past 15 years. We assessed allograft outcomes associated with deceased diabetic donors and compared them with that of standard and extended criteria donors (ECD) in the UNOS data registry. We identified 1982 recipients of diabetic standard criteria donors over a 10-year period from 1995 through 2004. Both overall and death-censored survival of organs from diabetic standard criteria donors was significantly better than that of organs obtained from nondiabetic ECD while inferior to that from nondiabetic standard criteria donors. Compared with ECD donors, diabetic donors had lower serum creatinine, less cold ischemia and these kidneys were less likely to be pump-perfused. Recipients of diabetic kidneys were younger and less likely to experience delayed graft function compared with recipient of ECD kidneys. More recently, many diabetic donor kidneys have been given to diabetic recipients with early graft survival being similar to that among nondiabetic recipients. These findings demonstrate the potential to expand and to improve utilization of this resource without compromising outcomes for recipients. Improved, evidence-based evaluation and allocation of deceased diabetic donor kidneys is needed to optimize their use.

Acute kidney injury before organ procurement is associated with worse long-term kidney graft outcome

BACKGROUND

As the disparity between the numbers of available organ donors and patients awaiting transplantation increases, different strategies have been proposed to extend the donor pool. Patients with acute kidney injury (AKI) developing during an intensive care unit (ICU) stay are often considered to be donors, but the long-term outcomes of such high-risk kidney transplantations is unknown. We analyzed the renal function and outcomes over 5 years of kidney grafts recovered from deceased donors diagnosed with AKI.

MATERIALS AND METHODS

We collected data from 61 deceased kidney donors, identified in 1 ICU, and 120 kidney graft recipients who underwent transplantation between January 1999 and December 2006. Donors were stratified according to the RIFLE classification, based on their creatinine and urine output change from admission to the ICU and organ procurement. Recipient kidney graft function (eGFR) calculated according to the MDRD (Modification of Diet in Renal Disease) equation was estimated every 6 months.

RESULTS

Among 61 donors, 10 (16.4%) developed AKI, including 7 classified as "risk", 2 as "injury," and 1 as "failure." The mean follow-up of kidney graft recipients was 49±18 months. The long-term risk for graft loss was significantly higher among the group of kidneys recovered from donors with AKI (27.8% vs 7.1%; P=.02; log-rank=0.07). Their excretory function was worse over the whole follow-up period.

CONCLUSION

Patients with kidney grafts obtained from the donors with AKI showed a higher risk for graft loss and worse excretory function upon long-term follow-up.