Transplant outcomes using kidneys from high KDPI acute kidney injury donors

Outcomes of Kidney Transplantation From Donors on Renal Replacement Therapy

Background

The increasing demand for organs has pushed transplant providers to expand kidney acceptance criteria. The use of kidneys from donors with AKI has been shown to provide good long-term graft survival. We aim to evaluate and compare the outcomes of deceased donor kidney transplantation from donors with acute kidney injury (AKI), either with or without renal replacement therapy (AKI-RRT) before donation.

Methods

A single-center retrospective review of all patients who underwent deceased donor kidney transplantation from AKI donors between 2009 and 2020 was performed. AKI donors were defined on the basis of donor terminal creatinine ≥2.0 mg/dL or use of RRT before donation. We compared the outcomes of recipients receiving a kidney from a donor with AKI versus AKI-RRT. Data are presented as medians (interquartile ranges) and numbers (percentages).

Results

Four hundred ninety-six patients were identified, of whom 300 (60.4%) were men with a median age of 57 y at transplantation. Thirty-nine patients received an AKI-RRT, whereas 457 received an AKI kidney. Donors in the AKI-RRT group were younger (28 versus 40), had less incidence of hypertension (15.3% versus 31.9%), and were more likely to be imported (94.9% versus 76.8%). There was a higher incidence of delayed graft function (72% versus 44%, P < 0.001) in the AKI-RRT group. Recipients in both groups had similar 90-d (100% versus 95.2%) and 1-y (100% versus 91.9%) graft survival. With a median follow-up of 5 y, there was no difference in death-censored graft survival in both groups (P = 0.83).

Conclusions

Careful selection of kidneys from donors with AKI on RRT can be safely used for kidney transplantation with favorable clinical outcomes.

Tailoring Kidney Transplant Strategies: Unraveling the Impact of Acute Kidney Injury and Preservation Methods Across Different Strata of Kidney Risk

BACKGROUND

The use of donor kidneys with acute kidney injury (AKI) aims to expand the organ pool, but uncertainty remains regarding their outcomes across different Kidney Donor Profile Index (KDPI) groups and preservation methods.

METHODS

We retrospectively analyzed 108 160 deceased donor kidney transplants from the OPTN database, focusing on adult recipients of kidneys from donors with or without AKI between December 2014 and December 2022. Propensity matching was used for each KDPI group (1-20, 21-59, 60-84, and 85-100), comparing donors with AKIN stages 0-1 to AKIN stages 2-3. Cox proportional hazards analysis assessed graft survival by AKIN stages and preservation type.

RESULTS

The use of AKIN stage 2-3 kidneys significantly increased over the study period. AKIN does not negatively impact graft survival in the KDPI 1-20 group and is linked to improved survival in KDPI 21-59 and 60-84. In the KDPI 85-100 group, AKIN stage 2-3 shows a trend toward increased graft failure. Pump preservation reduces delayed graft function (DGF) across most KDPI groups but does not consistently improve long-term survival, except in KDPI 85-100.

CONCLUSION

Transplantation with AKIN stage 2-3 kidneys is viable, but outcomes vary by KDPI group. Tailored guidelines should consider transplant center capabilities.

Reexamining Transplant Outcomes in Acute Kidney Injury Kidneys Through Machine Learning

BACKGROUND

Despite many people awaiting kidney transplant, kidney allografts from acute kidney injury (AKI) donors continue to be underutilized. We aimed to cluster kidney transplant recipients of AKI kidney allografts using an unsupervised machine learning (ML) approach.

METHODS

Using Organ Procurement and Transplantation Network-United Network for Organ Sharing (OPTN/UNOS) data, a consensus clustering cohort analysis was performed in 12 356 deceased donor kidney transplant recipients between 2015 and 2019 in whom donors had a terminal serum creatinine ≥1.5 mg/dL. Significant cluster characteristics were determined, and outcomes were compared.

RESULTS

The median donor terminal creatinine was 2.2 (interquartile range [IQR] 1.7-3.3) mg/dL. Cluster analysis was performed on 12 356 AKI kidney recipients, and three clinically distinct clusters were identified. Young, sensitized kidney re-transplant patients characterized Cluster 1. Cluster 2 was characterized by first-time kidney transplant patients with hypertensive and diabetic kidney diseases. Older diabetic recipients characterized Cluster 3. Clusters 1 and 2 donors were young and met standard kidney donor profile index (KDPI) criteria; Cluster 3 donors were older, more likely to have hypertension or diabetes, and meet high KDPI criteria. Cluster 1 had a higher risk of acute rejection, 3-year patient death, and graft failure. Cluster 3 had a higher risk of death-censored graft failure, patient death, and graft failure at 1 and 3 years. Cluster 2 had the best patient-, graft-, and death-censored graft survival at 1 and 3 years. Compared to non-AKI kidney recipients, the AKI clusters showed a higher incidence of delayed graft function (DGF, AKI: 43.2%, 41.7%, 45.3% vs. non-AKI: 25.5%); however, there were comparable long-term outcomes specific to death-censored graft survival (AKI: 93.6%, 93.4%, 90.4% vs. non-AKI: 92.3%), patient survival (AKI: 89.1%, 93.2%, 84.2% vs. non-AKI: 91.2%), and overall graft survival (AKI: 84.7%, 88.2%, 79.0% vs. non-AKI: 86.0%).

CONCLUSIONS

In this unsupervised ML approach study, AKI recipient clusters demonstrated differing, but good clinical outcomes, suggesting opportunities for transplant centers to incrementally increase kidney utilization from AKI donors.

Preoperative Risk Assessment of Early Kidney Graft Loss

Background

A large proportion of potential organ donors are not utilized for kidney transplantation out of risk of early allograft loss because of donor-related characteristics. These can be summarized using kidney donor profile index (KDPI). Because KDPI affects the choice of the recipient, the predictive ability of KDPI is tied to recipient attributes. These have been questioned to explain most of the predictive ability of KDPI. This study aims to quantify the effect of the donor on early graft loss (EGL) by accounting for nonrandom allocation.

Methods

This study included patients undergoing kidney transplantation from deceased donors between 2014 and 2020 from the Scientific Registry of Transplantation Recipients. EGL, defined as a return to dialysis or retransplantation during the first posttransplant year, was the primary endpoint. Nonrandom allocation and donor-recipient matching by KDPI necessitated the use of inverse probability treatment weighting, which served to assess the effect of KDPI and mitigate selection bias in a weighted Cox regression model.

Results

The study comprised 89 290 transplantations in 88 720 individual patients. Inverse probability treatment weighting resulted in a good balance of recipient covariates across values of continuous KDPI. Weighted analysis showed KDPI to be a significant predictor for short-term outcomes. A comparable (in terms of age, time on dialysis, previous transplants, gender, diabetes status, computed panel-reactive antibodies, and HLA mismatches) average recipient, receiving a kidney from a donor with KDPI 40-60 had a 3.5% risk of EGL increased to a risk of 7.5% if received a kidney from a KDPI >95 donor (hazard ratio, 2.3; 95% confidence interval, 1.9-2.7). However, for all-cause survival KDPI was less influential.

Conclusions

The predictive ability of KDPI does not stem from recipient confounding alone. In this large sample-sized study, modeling methods accounting for nonindependence of recipient selection verify graft quality to effectively predict short-term transplantation outcomes.

Impact of Deceased-donor Acute Kidney Injury on Kidney Transplantation

Even as record numbers of deceased donors are undergoing organ recovery, the global transplant community continues to struggle with a shortage of donor organs and a high organ discard rate. Acute kidney injury (AKI) occurs in many hospitalized patients, including up to 25% of patients in critical condition. Registry studies have shown a significant increase in nonrecovery or organ discard rates in AKI donors, despite most studies reporting similar clinical outcomes compared with non-AKI donors. This review aims to capture the salient information learned from these studies and to summarize the efforts that have been made to gain a more granular understanding of how kidneys from donors with AKI behave posttransplant. In particular, we reviewed the studies that analyzed the clinical outcomes in different stages of AKI and AKI in marginal donors, such as kidney donor profile index of >85%, older donors, and donation after circulatory death donors. We summarized studies investigating molecular biomarkers, transcriptomics, and possible future therapeutic targets for postdonation AKI.

Relationship of hemoglobin levels with outcomes in deceased donor kidney transplant: a retrospective cohort study

INTRODUCTION

Anemia is frequent in patients undergoing replacement therapy for kidney failure. Anemia in the pre- and post-transplantation period might be related to kidney transplant outcomes. The current study therefore sought to assess the relationship between anemia, delayed allograft function (DGF), chronic kidney allograft dysfunction (CAD), and death from any cause following kidney transplantation from a deceased donor.

METHODS

This was a retrospective study with 206 kidney transplant patients of deceased donors. We analyzed deceased donors' and kidney transplant patients' demographic data. Moreover, we compared biochemical parameters, anemia status, and medicines between DGF and non-DGF groups. Afterward, we performed a multivariate analysis. We also evaluated outcomes, such as CAD within one year and death in ten years.

RESULTS

We observed a lower frequency of pre-transplant hemoglobin concentration (Hb) but higher frequency of donor-serum creatinine and red blood transfusion within one week after transplantation in the group with DGF. In addition, there was an independent association between Hb concentration before transplantation and DGF [OR 0.252, 95%CI: 0.159-0.401; p < 0.001]. There was also an association between Hb concentration after six months of kidney transplantation and both CAD [OR 0.798, 95% CI: 0.687-0.926; p = 0.003] and death from any cause.

CONCLUSION

An association was found between pre-transplantation anemia and DGF and between anemia six months after transplantation and both CAD and death by any cause. Thus, anemia before or after transplantation affects the outcomes for patients who have undergone kidney transplantation from a deceased donor.

Validation of the kidney donor profile index (KDPI) for deceased donor kidney transplants in China

BACKGROUND

The kidney donor profile index (KDPI) evaluates kidney donor's age, height, weight, ethnicity, cause of death, high blood pressure, diabetes, exposure to hepatitis C and estimated glomerular filtration (eGFR). Kidneys with lower KDPI scores are expected to function longer that those with higher KPDI values. The applicability of KDPI score in Chinese kidney transplant donation has not yet been validated. This study evaluated the prognostic value of KDPI score in Chinese kidney transplant patients.

METHODS

A retrospective analysis was conducted on 184 deceased donors and 353 corresponding kidney transplant patients at the Organ Transplantation Department of Renmin Hospital of Wuhan University between 2018 and 2021. The donors and recipients were stratified into four groups based on their KDPI score: KDPI 85-100, KDPI 60-84, KDPI 21-59, and KDPI 0-20.

RESULTS

As expected, the KDPI 85-100 group was associated with a poor short-term renal function (both postoperative creatinine and eGFR with P > 0.05), a higher incidence of delayed graft function (DGF; 25.5% for KDPI 85-100 group vs. 10.2% for KDPI 60-84 group vs. 5.4% for KDPI 21-59 group vs. 0 for KDPI 0-20 group, all P > 0.05). Furthermore, the same groups showed worse 3-year patient survival rate: 86.3% for KDPI 85-100 group vs. 97.01% for KDPI 60-84 group vs. 97.83% for KDPI 21-59 group vs. 100% for KDPI 0-20 group, all P > 0.05); and renal survival rate: 82.6% for KDPI 85-100 group vs. 92.99% KDPI 60-84 group vs.97.83% for KDPI 21-59 group vs. 100% for KDPI 0-20 group, all P > 0.05). Our analysis showed that the KDPI score had a good predictive value for the survival of kidney transplants and patients in our center (area under the curve: 0.728 and 0.76, P > 0.05).

CONCLUSION

We recommend that the KDPI scoring system can be employed as an effective tool to predict kidney transplantation outcomes in deceased donation in China.

A Machine Learning-Driven Virtual Biopsy System For Kidney Transplant Patients

In kidney transplantation, day-zero biopsies are used to assess organ quality and discriminate between donor-inherited lesions and those acquired post-transplantation. However, many centers do not perform such biopsies since they are invasive, costly and may delay the transplant procedure. We aim to generate a non-invasive virtual biopsy system using routinely collected donor parameters. Using 14,032 day-zero kidney biopsies from 17 international centers, we develop a virtual biopsy system. 11 basic donor parameters are used to predict four Banff kidney lesions: arteriosclerosis, arteriolar hyalinosis, interstitial fibrosis and tubular atrophy, and the percentage of renal sclerotic glomeruli. Six machine learning models are aggregated into an ensemble model. The virtual biopsy system shows good performance in the internal and external validation sets. We confirm the generalizability of the system in various scenarios. This system could assist physicians in assessing organ quality, optimizing allograft allocation together with discriminating between donor derived and acquired lesions post-transplantation.

Duration of Dialysis in Acute Kidney Injury Donors and Transplant Outcomes

BACKGROUND

Acute kidney injury (AKI) kidneys, including those from donors on dialysis, are often underutilized, although there is increasing data available demonstrating good transplant outcomes. To date, data on the duration of donor dialysis and transplant outcomes are limited.

STUDY DESIGN

This was a single-center study of deceased donor kidney transplants from 2010 to 2022. The study cohort consisted of recipients of deceased donor kidney transplants from donors with AKI and on dialysis. Three groups were identified based on the predetermined interquartile range of donor dialysis duration: 1 to 2 dialysis days, 3 to 4 dialysis days, and 5 or more dialysis days.

RESULTS

During this period, 765 AKI deceased donor transplants were performed, of which 230 were from donors on dialysis. The median dialysis duration was 2 days with a maximum of 13 days. Across the 3 groups, there were no differences in recipient age (p = 0.23) or dialysis vintage (p = 0.70). Donor age (p = 0.86) and kidney donor profile index (p = 0.57) were comparable between the groups. Recipients of deceased donor kidney transplants from donors on dialysis 5 or more days had lower terminal creatinine levels (p = 0.003) and longer cold ischemia times (p = 0.04). Posttransplant, the median length of hospital stay was 3 days for all groups (p = 0.75). There were no differences in delayed graft function occurrence (94.4% vs 86.8% vs 92.1%, p = 0.19), duration of delayed graft function (p = 0.56), or readmissions (p = 0.99). At 1 year posttransplant, the estimated glomerular filtration rate (p = 0.76), patient survival (p = 0.82), or death-censored graft survival (p = 0.28) were comparable.

CONCLUSIONS

Excellent outcomes have been observed in AKI deceased donor kidney transplants, including those coming from donors on dialysis. In this small cohort, the duration of donor dialysis did not adversely affect outcomes. Cautious expansion of the donor pool, including donors on dialysis, should be considered given the ongoing organ shortage.

Outcomes with transplanting kidneys offered through expedited allocation

INTRODUCTION

Expedited out-of-sequence deceased donor kidney allocation is a strategy to avoid discards after early placement attempts have been unsuccessful. Our study aimed to assess outcomes and characteristics of these transplanted kidneys.

METHODS

KDPI matching was performed between expedited allocation (EA) and standard allocation (SA) deceased donor kidney transplants performed at our center.

RESULTS

Between 2018 and 2021, there were 225 EA offers, and 189 (84%) were transplanted. EA recipients were older (p = .007) and had shorter dialysis vintage (p < .0001). EA kidneys were likely to be nationally allocated (p < .001), have AKI (p < .0001) and longer CIT (p < .0001). There were no differences in EA and SA time-zero kidney biopsies (ci, p = .07; ct, p = .89; cv, p = .95; ah, p = .79). EA kidneys had more DGF (p = .0006), but there were no differences in DGF duration (p = .83), hospital length of stay (p = .43), 1- and 2-year eGFR (p = .16, p = .99), patient (p = .34), or death-censored graft (p = .66) survival.

CONCLUSION

During this study period, our center transplanted 189 kidneys through EA following local-regional declines. These kidneys often came from AKI donors and had more DGF but had similar outcomes to KDPI-matched SA kidneys. Although it has been suggested that EA has the potential to worsen transplant disparities, transplant center level decisions on organ acceptance contribute to these variations.

Single center experience and literature review of kidney transplantation from non-ideal donors with acute kidney injury: Risk and reward

INTRODUCTION

There is limited experience transplanting kidneys from either expanded criteria donors (ECD) or donation after circulatory death (DCD) deceased donors with terminal acute kidney injury (AKI).

METHODS

AKI kidneys were defined by a donor terminal serum creatinine level >2.0 mg/dL whereas non-ideal deceased donor (NIDD) kidneys were defined as AKI/DCD or AKI/ECDs.

RESULTS

From February 2007 to March 2023, we transplanted 266 single AKI donor kidneys including 29 from ECDs, 29 from DCDs (n = 58 NIDDs), and 208 from brain-dead standard criteria donors (SCDs). Mean donor age (43.7 NIDD vs. 33.5 years SCD), KDPI (66% NIDD vs. 45% SCD), and recipient age (57 NIDD vs. 51 years SCD) were higher in the NIDD group (all p < .01). Mean waiting times (17.8 NIDD vs. 24.2 months SCD) and dialysis duration (34 NIDD vs. 47 months SCD) were shorter in the NIDD group (p < .05). Delayed graft function (DGF, 48%) and 1-year graft survival (92.7% NIDD vs. 95.9% SCD) was similar in both groups. Five-year patient and kidney graft survival rates were 82.1% versus 89.9% and 82.1% versus 75.2% (both p = NS) in the NIDD versus SCD groups, respectively.

CONCLUSIONS

The use of kidneys from AKI donors can be safely liberalized to include selected ECD and DCD donors.

Breaking Barriers and Bridging Gaps: Advancing Diversity, Equity, and Inclusion in Kidney Transplant Care for Black and Hispanic Patients in the United States

Kidney transplantation offers better mortality and quality of life outcomes to patients with end-stage renal failure compared to dialysis. Specifically, living donor kidney transplantation is the best treatment for end-stage renal disease, since it offers the greatest survival benefit compared to deceased donor kidney transplant or dialysis. However, not all patients from all racial/ethnic backgrounds enjoy these benefits. While black and Hispanic patients bear the predominant disease burden within the United States, they represent less than half of all kidney transplants in the country. Other factors such as cultural barriers that proliferate myths about transplant, financial costs that impede altruistic donation, and even biological predispositions create a complex maze and can also perpetuate care inaccessibility. Therefore, blanket efforts to increase the overall donation pool may not extend access to vulnerable populations, who may require more targeted attention and interventions. This review uses US kidney transplantation data to substantiate accessibility differences amongst racial minorities as well as provides examples of successful institutional and national systemic level changes that have improved transplantation outcomes for all.

Past, Current, and Future Perspectives on Transplanting Acute Kidney Injury Kidneys

(1) Background: Acute kidney injury (AKI) kidneys have high non-utilization rates due to concerns regarding unfavorable outcomes. In this paper, we aimed to review the past, present, and future opinions on AKI kidneys. (2) Methods: A PubMed search was conducted for topics relevant to AKI kidney transplantation. (3) Results: Current short- and long-term data on AKI kidneys have demonstrated good outcomes including favorable graft function and survival. The role of procurement biopsies is controversial, but they have been shown to be beneficial in AKI kidneys by allowing clinicians to differentiate between reversible tubular injury and irreversible cortical necrosis. Machine perfusion has also been applied to AKI kidneys and has been shown to reduce delayed graft function (DGF). The incidence of DGF increases with AKI severity and its management can be challenging. Strategies employed to counteract this have included early initiation of dialysis after kidney transplantation, early targeting of adequate immunosuppression levels to minimize rejection risk, and establishment of outpatient dialysis. (4) Conclusions: Despite good outcomes, there continue to be barriers that impact AKI kidney utilization. Successful strategies have included use of procurement biopsies or machine perfusion and expectant management of DGF. With increasing experience, better use of AKI kidneys can result in additional opportunities to expand the donor pool.

Deceased Donor Kidney Nonuse: A Systematic Approach to Improvement

A large number of procured kidneys continue not to be transplanted, while the waiting list remains high.

Methods

We analyzed donor characteristics for unutilized kidneys in our large organ procurement organization (OPO) service area in a single year to determine the reasonableness of their nonuse and to identify how we might increase the transplant rate of these kidneys. Five experienced local transplant physicians independently reviewed unutilized kidneys to identify which kidneys they would consider transplanting in the future. Biopsy results, donor age, kidney donor profile index, positive serologies, diabetes, and hypertension were risk factors for nonuse.

Results

Two-thirds of nonused kidneys had biopsies with high degree of glomerulosclerosis and interstitial fibrosis. Reviewers identified 33 kidneys as potentially transplantable (12%).

Conclusions

Reducing the rate of unutilized kidneys in this OPO service area will be achieved by setting acceptable expanded donor characteristics, identifying suitable well-informed recipients, defining acceptable outcomes, and systematically evaluating the results of these transplants. Because the improvement opportunity will vary by region, to achieve a significant impact on improving the national nonuse rate, it would be useful for all OPOs, in collaboration with their transplant centers, to conduct a similar analysis.

Long-term outcomes of kidney transplantation from deceased donors with terminal acute kidney injury: Single center experience and literature review

INTRODUCTION

Long-term outcomes of kidney transplantation from deceased donors (DDKTs) with terminal acute kidney injury (AKI) are not well defined.

METHODS

Single center retrospective review of DDKTs from 1/31/07-12/31/19. AKI kidneys were defined by a doubling of the donor's admission serum creatinine (SCr) level AND a terminal SCr ≥2.0 mg/dl.

RESULTS

A total of 188 AKI DDKTs were performed, including 154 from brain-dead standard criteria donors (SCD). Mean donor age was 36 years and mean Kidney Donor Profile Index was 50%; mean admission and terminal SCr levels were 1.3 and 3.1 mg/dl, respectively. With a mean follow-up of 94 months (median 89 months), overall patient (both 71.3%) and graft survival (54% AKI vs. 57% non-AKI) rates were comparable to concurrent DDKTs from brain-dead non-AKI SCDs (n = 769). Delayed graft function (DGF) was higher in AKI kidney recipients (47% vs. 20% non-AKI DDKTs, p < .0001). DGF was associated with lower graft survival in recipients of both AKI and non-AKI SCD kidneys but the impact was earlier and more pronounced in non-AKI recipients.

CONCLUSIONS

Despite having more than twice the incidence of DGF, kidneys from deceased donors with terminal AKI have long-term outcomes comparable to non-AKI SCD kidneys and represent a safe and effective method to expand the donor pool.

Association of DGF and Early Readmissions on Outcomes Following Kidney Transplantation

Concerns regarding outcomes and early resource utilization are potential deterrents to broader use of kidneys at risk for delayed graft function (DGF). We assessed outcomes specific to kidneys with DGF that required early readmission following transplant. Three groups were identified: 1) recipients with DGF not requiring readmission, 2) recipients with DGF having an isolated readmission, and 3) recipients with DGF requiring ≥2 readmissions. Most recipients either required a single readmission (26.8%, n = 247) or no readmission (56.1%, n = 517); 17.1% (n = 158), had ≥2 readmissions. Recipients requiring ≥2 readmissions were likely to be diabetic (53.8%, p = 0.04) and have longer dialysis vintage (p = 0.01). Duration of DGF was longer with increasing number of readmissions (p < 0.001). There were no differences in patient survival for those with DGF and 0, 1 and ≥2 readmissions (p = 0.13). Graft survival, however, was lower for those with ≥2 readmissions (p < 0.0001). This remained true when accounting for death-censored graft loss (p = 0.0012). Additional subgroup analysis was performed on mate kidneys with and without DGF and mate kidneys, both with DGF, with and without readmissions. For these subgroups, there were no differences in patient or graft survival. As a whole, patients with DGF have excellent outcomes, however, patients with DGF requiring ≥2 readmissions have lower graft survival. A better understanding of recipient variables contributing to multiple readmissions may allow for improvements in the utilization of DGF at-risk kidneys.

Use of Machine Learning Consensus Clustering to Identify Distinct Subtypes of Kidney Transplant Recipients With DGF and Associated Outcomes

Data and transplant community opinion on delayed graft function (DGF), and its impact on outcomes, remains varied. An unsupervised machine learning consensus clustering approach was applied to categorize the clinical phenotypes of kidney transplant (KT) recipients with DGF using OPTN/UNOS data. DGF was observed in 20.9% (n = 17,073) of KT and most kidneys had a KDPI score <85%. Four distinct clusters were identified. Cluster 1 recipients were young, high PRA re-transplants. Cluster 2 recipients were older diabetics and more likely to receive higher KDPI kidneys. Cluster 3 recipients were young, black, and non-diabetic; they received lower KDPI kidneys. Cluster 4 recipients were middle-aged, had diabetes or hypertension and received well-matched standard KDPI kidneys. By cluster, one-year patient survival was 95.7%, 92.5%, 97.2% and 94.3% (p < 0.001); one-year graft survival was 89.7%, 87.1%, 91.6%, and 88.7% (p < 0.001). There were no differences between clusters after accounting for death-censored graft loss (p = 0.08). Clinically meaningful differences in recipient characteristics were noted between clusters, however, after accounting for death and return to dialysis, there were no differences in death-censored graft loss. Greater emphasis on recipient comorbidities as contributors to DGF and outcomes may help improve utilization of DGF at-risk kidneys.

Expanded Criteria Donor With Severe Acute Kidney Injury: Worth to Use?

BACKGROUND

Expanded criteria donors (ECDs) may present with acute kidney injury (AKI). Many transplantation centers refuse to use these kidneys because of concerns about poor transplant outcomes, resulting in a high discard rate. However, long-term results of ECDs with AKI (ECDs + AKI) have not been extensively studied.

METHODS

We retrospectively compared outcomes of ECDs with ECDs + AKI. Primary outcome was 5-year allograft and patient survival rate. Secondary outcomes were allograft function, rates of delayed graft function, and allograft rejection.

RESULTS

Of 743 deceased donor kidney transplant recipients, 95 ECD cases were included in this study. There were 38 patients (40%) with ECDs and 57 patients (60%) with ECDs + AKI. Mean donor creatinine was progressively higher with severity of AKI. Five-year graft and patient survival were comparable between ECDs and ECDs + AKI (80.6% vs 81.1%, P = .95 and 91.7% vs 88.7%, P = .73). Mean (SD) allograft estimated glomerular filtration rate was 36.7 (14.5) vs 40.6 (22.7) mL/min/1.73 m² with P = .61, respectively. Multivariate analysis showed factors associated graft loss were delayed graft function (P = .01) and donor-recipient age difference ≥10 years (P = .038), not AKI status.

CONCLUSIONS

Kidney transplant from ECDs + AKI has comparable allograft survival with ECDs without AKI. Use of ECDs + AKI is worthwhile and kidneys from ECDs + AKI should not be discarded. Recipient selection and perioperative care are important to optimize the use of scarce resource.

Deceased Donor Characteristics and Kidney Transplant Outcomes

Kidney transplantation is the therapy of choice for people living with kidney failure who are suitable for surgery. However, the disparity between supply versus demand for organs means many either die or are removed from the waiting-list before receiving a kidney allograft. Reducing unnecessary discard of deceased donor kidneys is important to maximize utilization of a scarce and valuable resource but requires nuanced decision-making. Accepting kidneys from deceased donors with heterogenous characteristics for waitlisted kidney transplant candidates, often in the context of time-pressured decision-making, requires an understanding of the association between donor characteristics and kidney transplant outcomes. Deceased donor clinical factors can impact patient and/or kidney allograft survival but risk-versus-benefit deliberation must be balanced against the morbidity and mortality associated with remaining on the waiting-list. In this article, the association between deceased kidney donor characteristics and post kidney transplant outcomes for the recipient are reviewed. While translating this evidence to individual kidney transplant candidates is a challenge, emerging strategies to improve this process will be discussed. Fundamentally, tools and guidelines to inform decision-making when considering deceased donor kidney offers will be valuable to both professionals and patients.

Outcomes of Simultaneous Liver-Kidney Transplantation Using Kidneys of Deceased Donors With Acute Kidney Injury

Outcomes from simultaneous liver-kidney transplantation (SLKT) when using kidneys from donors with acute kidney injury (AKI) have not been studied. We studied 5344 SLKTs between May 1, 2007, and December 31, 2019, by using Organ Procurement and Transplantation Network registry data supplemented with United Network for Organ Sharing-DonorNet data. Designating a donor as having AKI required by definition that the following criteria were met: (1) the donor's condition aligned with the Kidney Disease: Improving Global Outcomes (KDIGO) international consensus guidelines and the terminal serum creatinine (Scr) level was ≥1.5 times the minimum Scr level for deceased donors before organ recovery and (2) the terminal Scr level was ≥1.5 mg/dL (a clinically meaningful and intuitive Scr threshold for defining AKI for transplant providers). The primary outcomes were liver transplant all-cause graft failure (ACGF; defined as graft failures and deaths) and kidney transplant death-censored graft failure (DCGF) at 1 year after transplant. The donors with AKI were young, had good organ quality, and had a short cold ischemia time. In the study cohort, 4482 donors had no AKI, whereas 862 had AKI (KDIGO AKI stages: 1, n = 521; 2, n = 202; and 3, n = 138). In the group with AKI and the group with no AKI, respectively, liver ACGF at 1 year (11.1% versus 12.9% [P = 0.13]; hazard ratio [HR], 1.20; 95% confidence interval [CI], 0.97-1.49) and kidney DCGF at 1 year (4.6% versus 5.7% [P = 0.18]; HR, 1.27; 95% CI, 0.95-1.70) did not differ in the full multivariable Cox proportional hazard models. Selected kidneys from deceased donors with AKI can be considered for SLKT.

Outcomes of Dual Kidney Transplants from High KDPI Kidneys are Superior Compared to Single Kidney High KDPI Transplants at One-Year

Dual kidney transplantation (DKT), utilizing two adult kidneys from the same donor for one recipient, has been used as way to expand the available donor pool. These kidneys often come from high Kidney Donor Profile Index donors (KDPI >85%). Data comparing outcomes between high KDPI DKT and single kidney transplants (SKT) remain limited. We assessed outcomes of 336 high KDPI kidney transplants performed at our center; 11.0% (n = 37) were DKT. Recipients of DKT were older (p = 0.02) and donors had a higher KDPI score (median 96% vs. 91%, p<0.0001). DKT operative time was higher compared to SKT (+1.4 hours, p<0.0001). There were no differences in delayed graft function (54.1% vs. 51.5%, p = 0.77) and hospital length of stay (median 4.0 vs. 3.0 days, p = 0.21) between DKT and SKT. Grade I Clavien-Dindo complications occurred in 8.1% of DKT and 13.7% of SKT (p = 0.008). There were no grade IVa, IVb or V complications in either group. DKT had more glomerulosclerosis (p = 0.04), interstitial fibrosis (p = 0.02), tubular atrophy (p = 0.01), and arterial thickening (p = 0.03) on one-year protocol biopsies. Estimated glomerular filtration was higher for DKT at one- (p = 0.004) and two-years post-transplant (p = 0.01). There were no differences in patient (HR 1.3, 95% CI 0.5-3.3, p = 0.58) or graft (HR 1.1, 95% CI 0.5-2.3, p = 0.83) survival. Good outcomes can be achieved with DKT using high KDPI kidneys with moderate chronic changes. DKT is a good option to help further utilize high KDPI kidneys and minimize discard. This article is protected by copyright. All rights reserved.

Duration of delayed graft function and its impact on graft outcomes in deceased donor kidney transplantation

BACKGROUND

There is controversy regarding the impact of delayed graft function (DGF) on kidney transplant outcomes. We hypothesize that the duration of DGF, rather than DGF itself, is associated with long-term kidney graft function.

METHODS

We analyzed all deceased donor kidney transplants (DDKT) done at our center between 2008 to 2020. We determined factors associated with DGF duration. DGF duration was assessed at three 14-day intervals: < 14 DGF days, 14-27 DGF days, > 28 DGF days. We studied the impact of DGF duration on survival and graft function and resource utilization, including hospital length of stay and readmissions.

RESULTS

1714 DDKT recipients were included, 59.4% (n = 1018) had DGF. The median DGF duration was 10 days IQR (6,15). The majority of recipients (95%) had resolution of DGF within 28 days. Donor factors associated with DGF days were longer cold ischemia time, donor on inotropes, older age, donation after circulatory death, higher terminal creatinine, and hypertension. Recipient factors associated with increased DGF duration included male sex, length on dialysis before transplant, and higher body mass index. There were no differences in acute rejection events or interstitial fibrosis progression by 4 months when comparing DGF days. The median length of stay was 3 days. However, readmissions increased with increasing DGF duration. Death-censored graft survival was not associated with the length of DGF except when DGF lasted > 28 days.

CONCLUSIONS

Inferior graft survival was observed only in recipients of DDKT with DGF lasting beyond 28 days. DGF lasting < 28 days had no impact on graft survival. Duration of DGF, rather than DGF itself, is associated with graft survival.

TRIAL REGISTRATION

Retrospective study approved by Mayo Clinic IRB number ID: 20-011561.