Kidney Discard Research Articles

Trends in Discard of Kidneys from Hepatitis C Viremic Donors in the United States, 2020-2023

Trends in Discard of Kidneys from Hepatitis C Viremic Donors in the United States, 2020-2023

407.6: A pioneering study on factors influencing kidney discards.

407.6: A pioneering study on factors influencing kidney discards.

246.5: The current status of deceased donor kidney discard in Korea with a very long waiting time.

246.5: The current status of deceased donor kidney discard in Korea with a very long waiting time.

#1987 The current status of deceased donor kidney discard in Korea with a very long waiting time

Abstract Background and Aims Increasing rates of end stage kidney disease in Asia, including Korea, are very high; however, the rates of deceased donation in this area is much lower than those in the Western countries, leading to a serious discrepancy between donor organ need and supply. Therefore, efficient utilization of deceased donor kidneys with minimizing organ discard is essential. This nationwide study analyzed the current status of donor kidney discard in Korea. Method This study included deceased donor kidneys which are candidate for kidney transplantation between 2013 and 2018 in the Korean Network for Organ Sharing. Kidneys were procured bilaterally or unilaterally, or discarded bilaterally. Unilaterally- or bilaterally-procured kidneys were used for deceased donor kidney transplantation or discarded later. Kidney discard was defined as no-procurement or discard after procurement. We analysed risk factors affecting donor kidney discard using multivariable logistic regression analysis. Moreover, we analysed graft failure rate and mortality in kidney transplant patients according to discard pattern using Log rank test and multivariable Cox regression analysis. Results Among 5,592 deceased donor kidneys, numbers of no-procurement, single-procurement, and double-procurement were 385, 63, and 5,144, respectively. Most of unilaterally-procured kidneys were transplanted, whereas one kidney was discarded later. Bilaterally-procured kidneys were accompanied by two transplantations (n = 5,058), one transplantation with discard of the other kidneys (n = 33), or discard of both kidneys (n = 20). The kidney discard rate was 7.9% (n = 439), which seemed to be lower compared to that in the Western countries. The causes of no-procurement were universally organ damage and the common causes of kidney discard after procurement were organ damage (66.6%) and absence of available candidates (12.9%). While mean kidney donor profile index (KDPI) in the discard group (1.9 ± 0.7) was higher than that of transplantation group (1.5 ± 10.5, P < 0.001), a large overlap in the quality was observed. Risk factors for kidney discard were female sex (adjusted odds ratio [OR], 1.68; 95% confidence interval [CI], 1.31-2.15), hypertension (OR, 1.65; 95% CI, 1.27-2.14), diabetes mellitus (OR, 2.82; 95% CI, 2.12-3.75), high serum creatinine levels (OR, 1.89; 95% CI, 1.78-2.01), low hemoglobin levels (OR, 0.84; 95% CI, 0.79-0.90), and non-cerebrovascular cause of death (OR, 0.70; 95% CI, 0.55-0.89). When kidney transplantation using contralateral kidneys in the discard group was compared with that in the no-discard group, there were no significant differences in either graft failure rate or mortality between the two groups (P = 0.300). Furthermore, multivariable analysis showed that discard of the contralateral kidneys did not have a negative impact on either graft survival (hazard ratio 1.67; 95% CI, 0.74-3.77; P = 0.216) or patient survival (hazard ratio 0.86; 95% CI, 0.35-2.12; P = 0.749). Conclusion The discard rate of deceased donor kidneys was low in Korea with a very long waiting time and kidney transplant outcomes using contralateral kidneys in the discard group were comparable to those in the no-discard group, supporting maximal utilization of deceased donor kidneys would contribute to expanding a donor pool without compromising post-transplant outcomes.

Cytomegalovirus Matching in Deceased Donor Kidney Allocation: Results From a U.S. National Simulation Model.

Cytomegalovirus (CMV) infects >60% of adults and can pose an independent risk factor for allograft loss and mortality in solid organ transplant recipients. The purpose of this study is to evaluate the impact of a nationwide implementation of CMV seromatching (donor/recipient: D-/R- and D+/R+) in the U.S. deceased donor kidney allocation system (KAS). Adult candidates on the U.S. kidney-only transplant waiting list and deceased donor kidneys offered to the U.S. transplant centers were considered. A discrete-event simulation model, simulating the pre-COVID-19 period from January 1, 2015, to January 1, 2018, was used to compare the performances of currently employed KAS-250 policy (without CMV matching) to various simulated CMV matching policies parameterized by calculated panel reactive antibody exception threshold. Outcomes included CMV serodistribution, waiting time, access to transplantation among various groups, transplant rate, graft survival, kidney discard rate, and antigen-mismatch distribution, stratified by CMV serostatus. CMV matching policy with a calculated panel reactive antibody exception threshold of 50% (namely, the CMV">50%" policy) strikes a better balance between benefits and drawbacks of CMV matching. Compared with KAS-250, CMV">50%" reduced CMV high-risk (D+/R-) transplants (6.1% versus 18.1%) and increased CMV low-risk (D-/R-) transplants (27.2% versus 13.1%); increased transplant rate for CMV R- patients (11.54 versus 12.57) but decreased for R+ patients (10.68 versus 10.48), yielding an increase in aggregate (11.09 versus 10.94); and reduced mean time to transplantation (by 6 wk); and reduced kidney discard rate (25.7% versus 26.2%). Our findings underscore the feasibility and potential advantages of a nationwide CMV seromatching policy in kidney transplantation.

Wasted Potential: Decoding the Trifecta of Donor Kidney Shortage, Underutilization, and Rising Discard Rates

Kidney transplantation is a life-saving intervention for end-stage renal disease; yet, the persistent gap between organ demand and supply remains a significant challenge. This paper explores the escalating discard rates of deceased donor kidneys in the United States to assess trends, discard reasons, demographical differences, and preservation techniques. Data from the Scientific Registry of Transplant Recipients from 2010 to 2021 was analyzed using chi-squared tests for trend significance and logistic regression to estimate odds ratios for kidney discard. Over the last decade, discard rates have risen to 25% in 2021. Most discarded kidneys came from extended criteria donor (ECD) donors and elevated kidney donor profile index (KDPI) scores. Kidney biopsy status was a significant factor and predictor of discard. Discard rates varied greatly between Organ Procurement and Transplantation Network regions. Of reasons for discard, “no recipient located” reached a high of 60%. Additionally, there has been a twofold increase in hypothermic machine perfusion (HMP) since 2010, with transportation difficulties being the main reason for the discard of perfused kidneys. Our findings suggest a need to recalibrate organ utilization strategies, optimize the use of lower-quality kidneys through advanced preservation methods, and address the evolving landscape of organ allocation policies to reduce kidney discard rates.

Prediction of High-Risk Donors for Kidney Discard and Nonrecovery Using Structured Donor Characteristics and Unstructured Donor Narratives

Despite the unmet need, many deceased-donor kidneys are discarded or not recovered. Inefficient allocation and prolonged ischemia time are contributing factors, and early detection of high-risk donors may reduce organ loss. To evaluate the feasibility of machine learning (ML) and natural language processing (NLP) classification of donors with kidneys that are used vs not used for organ transplant. This retrospective cohort study used donor information (structured donor characteristics and unstructured donor narratives) from the United Network for Organ Sharing (UNOS). All donor offers to a single transplant center between January 2015 and December 2020 were used to train and validate ML models to predict donors who had at least 1 kidney transplanted (at our center or another center). The donor data from 2021 were used to test each model. Donor information was provided by UNOS to the transplant centers with potential transplant candidates. Each center evaluated the donor and decided within an allotted time whether to accept the kidney for organ transplant. Outcome metrics of the test cohort included area under the receiver operating characteristic curve (AUROC), F1 score, accuracy, precision, and recall of each ML classifier. Feature importance and Shapley additive explanation (SHAP) summaries were assessed for model explainability. The training/validation cohort included 9555 donors (median [IQR] age, 50 [36-58] years; 5571 male [58.3%]), and the test cohort included 2481 donors (median [IQR] age, 52 [40-59] years; 1496 male [60.3%]). Only 20% to 30% of potential donors had at least 1 kidney transplanted. The ML model with a single variable (Kidney Donor Profile Index) showed an AUROC of 0.69, F1 score of 0.42, and accuracy of 0.64. Multivariable ML models based on basic a priori structured donor data showed similar metrics (logistic regression: AUROC = 0.70; F1 score = 0.42; accuracy = 0.62; random forest classifier: AUROC = 0.69; F1 score = 0.42; accuracy = 0.64). The classic NLP model (bag-of-words model) showed its best metrics (AUROC = 0.60; F1 score = 0.35; accuracy = 0.59) by the logistic regression classifier. The advanced Bidirectional Encoder Representations From Transformers model showed comparable metrics (AUROC = 0.62; F1 score = 0.39; accuracy = 0.69) only after appending basic donor information. Feature importance and SHAP detected the variables (and words) that affected the models most. Results of this cohort study suggest that models using ML can be applied to predict donors with high-risk kidneys not used for organ transplant, but the models still need further elaboration. The use of unstructured data is likely to expand the possibilities; further exploration of new approaches will be necessary to develop models with better predictive metrics.

Viability of Transplanted Organs Based on Donor’s Age

Organ transplantation is becoming a major public health issue in many countries due to its attributable death rate and the excessive cost. There is a growing gap between organ supply and demand for organ transplantation in the US, which is causing major public health crisis. Twenty people on average die each day while waiting for a transplant because the supply of available organs from deceased donors does not meet the demand. National organ donation has increased in the past two decades; however, the number of individuals who need transplants has risen much faster as new patient is added to the national transplant waiting list every ten minutes. To address this disparity, not only the number of donors must be increased, but also the discard rate of available organs must be reduced. The kidney discard rate has increased by almost four times from the late 1980s to 2009, from approximately five percent to nearly 20 percent. So, it is important to investigate factors that may decrease the chance of an organ to be discarded as well as increase the survival time of transplanted organs. In this paper, we perform statistical survival analysis to study the impact of donor’s age on organ survival. Transplanted kidneys, livers, and intestines between 1987 and 2010 are investigated in this study. The results show that donor's age is an important factor for transplanted kidneys and livers donated by younger donors and survive for longer times while donor's age does not seem to be correlated with the survival time of transplanted intestines.

Temporal changes in the utilization of kidneys from hepatitis C virus–infected donors in the United States

Despite data demonstrating increased utilization of kidneys from hepatitis C virus (HCV)-infected donors, it is unknown whether this is due to an increase in the donor pool or improved organ utilization and whether data from early pilot trials were temporally associated with changes in organ utilization. We used data from the Organ Procurement and Transplantation Network on all kidney donors and recipients of kidney transplants from January 1, 2015, to March 31, 2022 to evaluate temporal changes using joinpoint regression. Our primary analyses compared donors on the basis of their HCV viremic status (HCV-infected vs HCV-negative). Kidney utilization changes were assessed by evaluating the kidney discard rate and kidneys transplanted per donor. A total of 81 833 kidney donors were included in the analysis. There was a statistically significant decrease in the discard rates of HCV-infected kidney donors from 40% to just over 20% over a 1-year period, with a concurrent increase in kidneys transplanted per donor. This increased utilization occurred in tandem with the publication of pilot trials involving HCV-infected kidney donors in HCV-negative recipients rather than an increase in the donor pool. Ongoing clinical trials may strengthen existing data, which could result in this practice becoming the accepted standard of care.

Impact of donor kidney biopsy on kidney yield and posttransplant outcomes

Procurement biopsy is performed to determine kidney quality, but evidence supporting such association is poor. We investigated the impact of glomerulosclerosis percentage (GS%) on kidney yield and patient outcomes. Information on deceased kidney donors from July 1, 2017, to June 30, 2019, was collected. Association between GS% and kidney yield (number of kidneys procured per donor) and posttransplant graft and patient outcomes were studied. Maximal GS% and minimal GS% were calculated to determine the relationship between GS% and kidney yield; minimal GS% only for correlation with posttransplant outcomes. Multinomial logistic regression and Cox models with least absolute shrinkage and selection operator were used to analyze the association of GS% with kidney yield and posttransplant outcomes, respectively. The kidney yield was 1.63 when maximal GS% and minimal GS% were <5%, but was 0.88 when both GS% were >20%. The hazard ratio for graft failure 1 year after transplant was 1.05 when minimal GS% was 16% to 20%, but was 1.3 for GS% of >20%. The hazard ratio for mortality increased from 1 to 1.2 when minimal GS% reached >20%. In summary, higher GS% was associated with lower kidney yield and inferior posttransplant outcomes. Incorporation of GS% into Scientific Registry of Transplant Recipients models may reassure organ procurement organizations and transplant centers pursuing kidneys with relatively high GS% levels, thereby reducing kidney discard rates.

Identify Hard-to-Place Kidneys for Early Engagement in Accelerated Placement With a Deep Learning Optimization Approach

Recommended practices that follow match-run sequences for hard-to-place kidneys succumb to many declines, accruing cold ischemic time and exacerbating kidney quality that may lead to unnecessary kidney discard. Hard-to-place deceased donor kidneys accepted and transplanted later in the match-run sequence may threaten higher graft failure rates. Accelerated placement is a practice for organ procurement organizations (OPOs) to allocate high-risk kidneys out of sequence and reach patients at aggressive transplant centers. The current practice of assessing hard-to-place kidneys and engaging in accelerated kidney placements relies heavily on the kidney donor profile index (KDPI) and the number of declines. Although this practice is reasonable, it also accrues cold ischemic time and increases the risk for kidney discard. We use a deep learning optimization approach to quickly identify kidneys at risk for discard. This approach uses Organ Procurement and Transplantation Network data to model kidney disposition. We filter discards and develop a model to predict transplant and discard of recovered and not transplanted kidneys. Kidneys with a higher probability of discard are deemed hard-to-place kidneys, which require early engagement for accelerated placement. Our approach will aid in identifying hard-to-place kidneys before or after procurement and support OPOs to deviate from the match-run for accelerated placement. Compared with the KDPI-only prediction of the kidney disposition, our approach demonstrates a 10% increase in correctly predicting kidneys at risk for discard. Future work will include developing models to identify candidates with an increased benefit from using hard-to-place kidneys.

Improving assessment in kidney transplantation by multitask general path model

BackgroundKidney transplantation is a pivotal intervention for individuals suffering from end-stage renal diseases, offering them the potential for restored health and an enhanced quality of life. However, the successful outcome of these transplantation procedures relies significantly on the careful matching of donor kidneys with compatible recipients. Unfortunately, the current kidney-matching process overlooks viability changes during preservation. The objective of this study is to investigate the potential for forecasting heterogeneous kidney viability using historical datasets to enhance kidney-matching decision-making. MethodsWe present a multitask general path model designed for continuous forecasting of kidney viability during preservation. This model quantifies likely viability trajectories of donor kidneys based on pathologist-provided biopsy scores during preservation, explicitly addressing both inter-kidney similarities and individual differences. To validate our model, we conducted viability assessments on six recently procured porcine kidneys and needle biopsy insertion experiments on phantoms, utilizing a leave-one-kidney-out cross-validation approach. ResultsOur proposed model consistently exhibited the lowest forecasting error (averaged root mean squared error, RMSEbegin=0.61 at the beginning and RMSEend<0.05 at the end of kidney preservation) when compared to widely-adopted benchmark models, including multitask learning (RMSEbegin=0.65, RMSEend=0.54), general path (RMSEbegin=0.58, RMSEend=0.49), and generalized linear models (RMSEbegin=0.59, RMSEend=0.56) in the kidney viability assessment study. Additionally, across all testing scenarios, the forecasting RMSE of our model rapidly diminished with minimal initial kidney samples during preservation. Similar patterns were observed from the needle biopsy insertion study. ConclusionsIn both validation studies, our model outperformed benchmark models and exhibited rapid learning with limited initial samples. This approach holds promise for enhancing kidney transplantation decision-making, including improving tissue extraction accuracy through needle biopsy data analysis. By implementing this model across various kidney assessment stages in transplantation, we aim to reduce kidney discards and benefit a larger number of patients.

Influence of organ quality on the observed association between deceased donor kidney procurement biopsy findings and graft survival

Deceased donor kidney procurement biopsies findings are the most common reason for kidney discard. Retrospective studies have found inconsistent associations with post-transplant outcomes but may have been limited by selection bias because kidneys with advanced nephrosclerosis from high-risk donors are typically discarded. We conducted a retrospective cohort study of kidneys transplanted in the United States from 2015 to 2019 with complete biopsy data available, defining "suboptimal histology" as glomerulosclerosis ≥11%, IFTA ≥mild, and/or vascular disease ≥mild. We used time-to-event analyses to determine the association between suboptimal histology and death-censored graft failure after stratification by kidney donor profile index (KDPI) (≤35%, 36%-84%, ≥85%) and final creatinine (<1mg/dl, 1-2mg/dl, >2mg/dl). Among 30 469 kidneys included, 36% had suboptimal histology. In adjusted analyses, suboptimal histology was associated with death-censored graft failure among kidneys with KDPI 36-84% (HR 1.22, 95% CI 1.09-1.36), but not KDPI≤35% (HR 1.24, 0.94-1.64) or ≥ 85% (HR 0.99, 0.81-1.22). Similarly, suboptimal histology was associated with death-censored graft failure among kidneys from donors with creatinine 1-2mg/dl (HR 1.39, 95% CI 1.20-1.60) but not <1mg/dl (HR 1.07, 0.93-1.23) or >2mg/dl (HR 0.95, 0.75-1.20). The association of procurement histology with graft longevity among intermediate-quality kidneys that were likely to be both biopsied and transplanted suggests biopsies provide independent organ quality assessments.

Early Effect of the Circular Model of Kidney Allocation in the United States.

In March 2021, the United States implemented a new kidney allocation system (KAS250) for deceased donor kidney transplantation (DDKT), which eliminated the donation service area-based allocation and replaced it with a system on the basis of distance from donor hospital to transplant center within/outside a radius of 250 nautical miles. The effect of this policy on kidney discards and logistics is unknown. We examined discards, donor-recipient characteristics, cold ischemia time (CIT), and delayed graft function (DGF) during the first 9 months of KAS250 compared with a pre-KAS250 cohort from the preceding 2 years. Changes in discards and CIT after the onset of COVID-19 and the implementation of KAS250 were evaluated using an interrupted time-series model. Changes in allocation practices (biopsy, machine perfusion, and virtual cross-match) were also evaluated. Post-KAS250 saw a two-fold increase in kidneys imported from nonlocal organ procurement organizations (OPO) and a higher proportion of recipients with calculated panel reactive antibody (cPRA) 81%-98% (12% versus 8%; P <0.001) and those with >5 years of pretransplant dialysis (35% versus 33%; P <0.001). CIT increased (mean 2 hours), including among local OPO kidneys. DGF was similar on adjusted analysis. Discards after KAS250 did not immediately change, but we observed a statistically significant increase over time that was independent of donor quality. Machine perfusion use decreased, whereas reliance on virtual cross-match increased, which was associated with shorter CIT. Early trends after KAS250 show an increase in transplant access to patients with cPRA>80% and those with longer dialysis duration, but this was accompanied by an increase in CIT and a suggestion of worsening kidney discards.

The New Distance-Based Kidney Allocation System: Implications for Patients, Transplant Centers, and Organ Procurement Organizations.

Purpose of ReviewThe goal of deceased donor kidney allocation policy is to provide objective prioritization for donated kidneys, and policy has undergone a series of revisions in the past decade in attempt to achieve equity and utility in access to kidney transplantation. Most recently, to address geographic disparities in access to kidney transplantation, the Kidney Allocation System changed to a distance-based allocation system—colloquially termed “KAS 250”—moving away from donor service areas as the geographic basis of allocation. We review the early impact of this policy change on access to transplant for patients, and on complexity of organ allocation and transplantation for transplant centers and organ procurement organizations.Recent FindingsBroader sharing of kidneys has increased complexity of the allocation system, as transplant centers and OPOs now interact in larger networks. The increased competition resulting from this system, and the increased operational burden on centers and OPOs resulting from greater numbers of organ offers, may adversely affect organ utilization. Preliminary results suggest an increase in transplant rate overall but a trend toward higher kidney discard and increased cold ischemia time.SummaryThe KAS 250 allocation policy changed the geographic basis of deceased donor kidney distribution in a manner that is intended to reduce geographic disparities in access to kidney transplantation. Close monitoring of this policy’s impact on patients, transplant center behavior, and process measures is critical to the aim of maximizing access to transplant while achieving transplant equity.

Short-term outcome of kidney transplantation from deceased donors with nephrolithiasis.

Shortage of kidney allografts is a major barrier to end-stage renal disease patients receiving kidney transplantation, and it is necessary to enlarge the donor pool and find better ways of using available allografts. The global incidence of nephrolithiasis is increasing, nephrolithiasis affects approximately 10% of adults worldwide, and it also affects the kidney donors. However, there is little information about the use of cadaveric kidney allografts with nephrolithiasis. This study aims to evaluate the safety and outcome of kidney transplantation with allografts from the deceased donors with nephrolithiasis. A total of 520 deceased donors who was at least 10 years old, and 945 adult recipients with single kidney transplantation at the Department of Kidney Transplantation, the Second Xiangya Hospital from 2016 to 2020 were included in this study. The donors were divided into 2 groups according to nephrolithiasis diagnoses: The donors with nephrolithiasis (D + ) and the donors without nephrolithiasis (D - ). The recipients were assigned into 3 groups according to their donors and the allografts they received: The allografts from donors without nephrolithiasis (D - K - ), the allografts without nephrolithiasis from donors with nephrolithiasis (D + K - ), and the allografts with nephrolithiasis (D + K + ). The demographic and clinical data of enrolled subjects were retrospectively analyzed. The allograft discard ratio between different donors were analyzed. The one-year survival of allografts and recipients, as well as the allograft function and the complications of kidney transplantation were compared. Fifty out of 520 donors had nephrolithiasis, and the nephrolithiasis incidence was 9.6%. We recovered 1 040 kidneys, and total discard rate was 4.4% (46/1 040). The D + group had a rate of 7% discard. The donors with kidney discard accounted for 12% in the D + group, and this was higher than that of donors in the D - group (5.1%, P <0.05). The total incidence of delayed graft function (DGF) was 7.5%, and there were no significant differences in the incidence of DGF in recipients among the D - K - , D + K - , and D + K + group (7.5% vs 6.5% vs 8.2%, P> 0.05). During the one-year follow-up, 8 allografts lost function and 19 recipients died with a functional allograft. Recipients in the D - K - , D + K - ,and D + K + groups also had no significant difference between a one-year allograft and patient survival rate ( P >0.05). However, recipients in the D + K + group had a higher level of serum creatinine [(139.2±62.46) μmol/L vs (117.19±51.22) μmol/L, P <0.05] and lower estimated glomerular filtration rate [eGFR; (56.67±23.31) mL/(min·1.73 m -2 ) vs (66.86±21.90) mL/(min·1.73 m -2 ), P <0.05] compared with recipients in the D - K - group at 12 months after transplantation. During the first year after transplantation, 4 recipients developed urolithiasis, and recipients who received allografts from the D + group donors had a higher incidence of urolithiasis than those who received allografts from the D - group donors (2.2% vs 0.2%, P <0.05). There were no significant differences in the incidence of urinary tract infections and ureteral strictures at 1 year between recipients of D + and D - donors (both P >0.05). The cadaveric kidney allografts with nephrolithiasis could be safely used for transplantation, and the short-term outcome is acceptable. However, nephrolithiasis in donors may increase the rate of kidney discard, disturb the short-term function of allografts, and increase the risk of urolithiasis in recipients. Further research with a long-term study is needed to verify the long-term outcome of kidney transplantation using cadaveric kidney allografts with nephrolithiasis.

Recoverability of Diabetic Nephropathy of Donor Kidney After Kidney Transplantation.

Some kidney donors have diabetes, and little of their natural course of diabetic nephropathy (DN) is known. The aim of this study was to analyze the changes in pathologic lesions in the diabetic donor kidney after KT by performing protocol biopsy two weeks and one year after KT. This retrospective study included 103 patients who underwent KT, with kidneys from donors with a history of diabetes mellitus (DM). Among them, data of 34 patients who underwent biopsy two weeks and one year after KT were reviewed. Biopsy specimens were reviewed using light microscopy and electron microscopy. Glomerular basement membrane (GBM) thickness at 2 weeks and 1 year was compared. Biopsy showed that DN occurred in 29 of the 34 patients. Only trivial histological changes were observed in 22 patients (64.7%), including 5 patients who did not show DN. At one year after transplantation, there was no change in the DN histologic class in 26 patients (76.5%), and there was no statistically significant difference in the change in GBM thickness. This pattern was observed regardless of the recipient’s DM or glycemic control. With this understanding, clinicians can use kidneys from DM donors with more comfort, thereby reducing the kidney discard rate.

Dual impact of donor service area removal from kidney allocation system and Coronavirus Disease 2019 pandemic on access to transplantation.

IntroductionDonor service area was removed from kidney and pancreas allocation system in the United States on March 15, 2021 in favor of a distance based policy to provide geographic equity to access to transplantation. The policy change was introduced at a time when ongoing Coronavirus Disease 2019 (COVID‐19) pandemic cases were declining following the first delta wave.MethodsIn this Scientific Registry of Transplant Recipients based study, deceased donor kidney transplant recipients between March 15 and December 2 of 2019, 2020 and 2021 were compared representing pre‐policy change, pre‐COVID cohort; pre‐policy change, early COVID cohort; and post‐policy change, late COVID cohort.ResultsThere were 11336, 11808, and 12914 kidney transplants in the 2019, 2020, and 2021 cohorts, respectively. Proportion of kidney transplants increased from 8798 (78%) to 9496 (80%) to 11152 (86%), and decreased from 2538 (22%) to 2312 (20%) to 1762 (14%) within and beyond 250 nautical miles in subsequent years. Median distance between donor and transplant hospital increased (73 vs. 63 vs. 119 nautical miles, P < .001) and mean cold ischemia time increased (18.1 vs. 17.8 vs. 19.9 h, P < .001). Access to transplantation did not change for various racial groups (P = .07), pediatric patients (P = .29), dialysis vintage of >5 years (P = .21), veterans (P = .07) and decreased for those with calculated PRA of 99% and 100% (P < .001). Rate of kidney discard (19.6% vs. 20.4% vs. 24%) remained high. Although there were numerical increases in transplants from donors with donation after circulatory death, donor acute kidney injury, kidney donor profile index >85% and donor age >60 years in successive years, rates of kidney discard also increased proportionally.ConclusionImprovement in the access to transplantation following the policy change was attenuated by the concurrent prevalence of the COVID‐19 pandemic.

242.3: Is Kidney Time-Zero Biopsy Useful to Predict Graft Function at 1-Year?

Introduction: Clinical and histological characteristics of donors are known to influence graft outcome after kidney transplantation. One of the most common reasons for donor kidney discard is unfavorable histology on procurement biopsies. Many centers perform time-zero biopsies (Bx0), although there is no consensus about the histological findings significance or its association with post-transplant biopsies results. We aim to determine if findings in Bx0 could predict the allograft function at 1-year after transplantation. Methods: Adult kidney-transplant patients from October 2014 to December 2020 with Bx0, post-transplant biopsy performed and at least 1-year follow-up were included. Recipient’s gender and age, clinical donor characteristics, histological findings in Bx0 and post-transplant biopsies and 1-year creatinine levels were analyzed using SPSS® V.25. Results: During the analyzed period 138 kidney transplants were performed. Bx0 was performed in 68 (49%) patients, and of those, 60 patients (88%) had at least one post-transplant biopsy. Mean age was 46 ± 14-year-old and 37 (54%) were male. Fifty-three patients (78%) received a kidney from deceased donor and 15 (22%) from living donor. Donor mean age was 43 ± 13-year-old. Fourteen (20%) had hypertension and the mean body mass index (BMI) was 27.3 ± 5.1 kg/m2. Donor’s mean serum creatinine before procurement surgery was 1.14 ± 0.53 mg/dL and the mean cold ischemia time (CIT) was 17:21 ± 9:40hs. Bx0 histological findings were: acute tubular necrosis (ATN) in 62 biopsies (19%), glomerulosclerosis (GS) in 40 (59%) and interstitial fibrosis and tubular atrophy (IFTA) in 41 (60%), with a mean of 6 ± 9% and 5 ± 7% respectively; 15 (22%) had arteriolar hyaline thickening. A risk factor for allograft GS was donor’s age >43-year-old (OR 4.4 95%IC 1.7 – 11.7 p= 0.000). In addition, we found that donor’s age >43-year-old and history of hypertension were risk factors for IFTA (OR 3.7 95%CI 1.6 – 8.8 p= 0.000 and OR 2.57 95%CI 1.4 – 4.4 p= 0.004 respectively). The mean of 1-year serum creatinine was 1.8 ± 1.6 mg/dL. Clinical and pathological parameter effects on 1-year serum creatinine are shown in table 1. The risk factors for worse outcomes in terms of 1-year serum creatinine are shown in table 2. We also found that GS and IFTA persist in post-transplant biopsies in 85% and 100% of patients respectively. Conclusion: We have found that not only donor age and hypertension are risk factors for pathological findings in Bx0 but also those findings impact negatively on 1-year serum creatinine.

Utilization and outcomes of deceased donor SARS-CoV-2–positive organs for solid organ transplantation in the United States

Coronavirus disease‐19 has had a marked impact on the transplant population and processes of care for transplant centers and organ allocation. Several single‐center studies have reported successful utilization of deceased donors with positive severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) tests. Our aims were to characterize testing, organ utilization, and transplant outcomes with donor SARS‐CoV‐2 status in the United States. We used Scientific Registry of Transplant Recipients data from March 12, 2020 to August 31, 2021 including a custom file with SARS‐CoV‐2 testing data. There were 35 347 donor specimen SARS‐CoV‐2 tests, 77.5% upper respiratory samples, 94.6% polymerase chain reaction tests, and 1.2% SARS‐CoV‐2–positive tests. Donor age, gender, history of hypertension, and diabetes were similar by SARS‐CoV‐2 status, while positive SARS‐CoV‐2 donors were more likely African‐American, Hispanic, and donors after cardiac death (p‐values <.01). Recipient demographic characteristics were similar by donor SARS CoV‐2 status. Adjusted donor kidney discard (odds ratio = 2.08, 95% confidence interval [CI] 1.66–2.61) was higher for SARS‐CoV‐2–positive donors while donor liver (odds ratio = 0.44, 95% CI 0.33–0.60) and heart recovery (odds ratio = 0.44, 95% CI 0.31–0.63) were significantly reduced. Overall post‐transplant graft survival for kidney, liver, and heart recipients was comparable by donor SARS‐CoV‐2 status. Cumulatively, there has been significantly lower utilization of SARS‐CoV‐2 donors with no evidence of reduced recipient graft survival with variations in practice over time.