Characterizing proximity and transfers of deceased organ donors to donor care units in the United States.

Some United States organ procurement organizations transfer deceased organ donors to donor care units (DCUs) for recovery procedures. We used Organ Procurement and Transplantation Network data, from April 2017 to June 2021, to describe the proximity of adult deceased donors after brain death to DCUs and understand the impact of donor service area (DSA) boundaries on transfer efficiency. Among 19 109 donors (56.1% of the cohort) in 25 DSAs with DCUs, a majority (14 593 [76.4%]) were in hospitals within a 2-hour drive. In areas with DCUs detectable in the study data set, a minority of donors (3582 of 11 532 [31.1%]) were transferred to a DCU; transfer rates varied between DSAs (median, 27.7%, range, 4.0%-96.5%). Median hospital-to-DCU driving times were not meaningfully shorter among transferred donors (50 vs 51 minutes for not transferred, P < .001). When DSA boundaries were ignored, 3241 cohort donors (9.5%) without current DCU access were managed in hospitals within 2 hours of a DCU and thus potentially eligible for transfer. In summary, approximately half of United States deceased donors after brain death are managed in hospitals in DSAs with a DCU. Transfer of donors between DSAs may increase DCU utilization and improve system efficiency.

Design, cohort profile and comparison of the KTD-Innov study: a prospective multidimensional biomarker validation study in kidney allograft rejection.

There is an unmet need for robust and clinically validated biomarkers of kidney allograft rejection. Here we present the KTD-Innov study (ClinicalTrials.gov, NCT03582436), an unselected deeply phenotyped cohort of kidney transplant recipients with a holistic approach to validate the clinical utility of precision diagnostic biomarkers. In 2018-2019, we prospectively enrolled consecutive adult patients who received a kidney allograft at seven French centers and followed them for a year. We performed multimodal phenotyping at follow-up visits, by collecting clinical, biological, immunological, and histological parameters, and analyzing a panel of 147 blood, urinary and kidney tissue biomarkers. The primary outcome was allograft rejection, assessed at each visit according to the international Banff 2019 classification. We evaluated the representativeness of participants by comparing them with patients from French, European, and American transplant programs transplanted during the same period. A total of 733 kidney transplant recipients (64.1% male and 35.9% female) were included during the study. The median follow-up after transplantation was 12.3 months (interquartile range, 11.9-13.1 months). The cumulative incidence of rejection was 9.7% at one year post-transplant. We developed a distributed and secured data repository in compliance with the general data protection regulation. We established a multimodal biomarker biobank of 16,736 samples, including 9331 blood, 4425 urinary and 2980 kidney tissue samples, managed and secured in a collaborative network involving 7 clinical centers, 4 analytical platforms and 2 industrial partners. Patients' characteristics, immune profiles and treatments closely resembled those of 41,238 French, European and American kidney transplant recipients. The KTD-Innov study is a unique holistic and multidimensional biomarker validation cohort of kidney transplant recipients representative of the real-world transplant population. Future findings from this cohort are likely to be robust and generalizable.

Association of donor hepatitis C virus infection status and risk of BK polyomavirus viremia after kidney transplantation.

Kidney transplantation (KT) from deceased donors with hepatitis C virus (HCV) into HCV-negative recipients has become more common. However, the risk of complications such as BK polyomavirus (BKPyV) remains unknown. We assembled a retrospective cohort at four centers. We matched recipients of HCV-viremic kidneys to highly similar recipients of HCV-aviremic kidneys on established risk factors for BKPyV. To limit bias, matches were within the same center. The primary outcome was BKPyV viremia ≥1000 copies/ml or biopsy-proven BKPyV nephropathy; a secondary outcome was BKPyV viremia ≥10 000 copies/ml or nephropathy. Outcomes were analyzed using weighted and stratified Cox regression. The median days to peak BKPyV viremia level was 119 (IQR 87-182). HCV-viremic KT was not associated with increased risk of the primary BKPyV outcome (HR 1.26, p = .22), but was significantly associated with the secondary outcome of BKPyV ≥10 000 copies/ml (HR 1.69, p = .03). One-year eGFR was similar between the matched groups. Only one HCV-viremic kidney recipient had primary graft loss. In summary, HCV-viremic KT was not significantly associated with the primary outcome of BKPyV viremia, but the data suggested that donor HCV might elevate the risk of more severe BKPyV viremia ≥10 000 copies/ml. Nonetheless, one-year graft function for HCV-viremic recipients was reassuring.

Acute Kidney Injury in Deceased Organ Donors and Kidney Transplant Outcomes: A National Cohort Study Using a Novel Data Source.

OBJECTIVE: The aim of this study was to determine graft function and survival for kidney transplants from deceased donors with acute kidney injury (AKI) that persists at the time of organ procurement. BACKGROUND: Kidneys from donors with AKI are often discarded and may provide an opportunity to selectively expand the donor pool. METHODS: Using Organ Procurement and Transplantation Network and DonorNet data, we studied adult kidney-only recipients between May 1, 2007 and December 31, 2016. DonorNet was used to characterize longitudinal creatinine trends and urine output. Donor AKI was defined using KDIGO guidelines and terminal creatinine ≥1.5 mg/dL. We compared outcomes between AKI kidneys versus "ideal comparator" kidneys from donors with no or resolved AKI stage 1 plus terminal creatinine <1.5mg/dL. We fit proportional hazards models and hierarchical linear regression models for the primary outcomes of all-cause graft failure (ACGF) and 12-month estimated glomerular filtration rate (eGFR), respectively. RESULTS: We identified 7660 donors with persistent AKI (33.2% with AKI stage 3) from whom ≥1 kidney was transplanted. Observed rates of ACGF within 3 years were similar between recipient groups (15.5% in AKI vs 15.1% ideal comparator allografts, P = 0.2). After risk adjustment, ACGF was slightly higher among recipients of AKI kidneys (adjusted hazard ratio 1.05, 95% confidence interval: 1.01-1.09). The mean 12-month eGFR for AKI kidney recipients was lower, but differences were not clinically important (56.6 vs 57.5 mL/min/1.73m 2 for ideal comparator kidneys; P < 0.001). There were 2888 kidneys discarded from donors with AKI, age ≤65 years, without hypertension or diabetes, and terminal creatinine ≤4 mg/dL. CONCLUSION: Kidney allografts from donors with persistent AKI are often discarded, yet those that were transplanted did not have clinically meaningful differences in graft survival and function.

Assessment of the Utility of Kidney Histology as a Basis for Discarding Organs in the United States: A Comparison of International Transplant Practices and Outcomes.

BACKGROUND: Many kidneys donated for transplant in the United States are discarded because of abnormal histology. Whether histology adds incremental value beyond usual donor attributes in assessing allograft quality is unknown. METHODS: This population-based study included patients who received a deceased donor kidney that had been biopsied before implantation according to a prespecified protocol in France and Belgium, where preimplantation biopsy findings are generally not used for decision making in the allocation process. We also studied kidneys that had been acquired from deceased United States donors for transplantation that were biopsied during allocation and discarded because of low organ quality. Using donor and recipient characteristics, we fit multivariable Cox models for death-censored graft failure and examined whether predictive accuracy (C index) improved after adding donor histology. We matched the discarded United States kidneys to similar kidneys transplanted in Europe and calculated predicted allograft survival. RESULTS: In the development cohort of 1629 kidney recipients at two French centers, adding donor histology to the model did not significantly improve prediction of long-term allograft failure. Analyses using an external validation cohort from two Belgian centers confirmed the lack of improved accuracy from adding histology. About 45% of 1103 United States kidneys discarded because of histologic findings could be accurately matched to very similar kidneys that had been transplanted in France; these discarded kidneys would be expected to have allograft survival of 93.1% at 1 year, 80.7% at 5 years, and 68.9% at 10 years. CONCLUSIONS: In this multicenter study, donor kidney histology assessment during allocation did not provide substantial incremental value in ascertaining organ quality. Many kidneys discarded on the basis of biopsy findings would likely benefit United States patients who are wait listed.

Racial disparities in preemptive waitlisting and deceased donor kidney transplantation: Ethics and solutions.

Kidney transplantation prior to dialysis, known as "preemptive transplant," enables patients to live longer and avoid the substantial quality of life burdens due to chronic dialysis. Deceased donor kidneys are a public resource that ought to provide health benefits equitably. Unfortunately, White, better educated, and privately insured patients enjoy disproportionate access to preemptive transplantation using deceased donor kidneys. This problem has persisted for decades and is exacerbated by the first-come, first-served approach to kidney allocation for predialysis patients. In this Personal Viewpoint, we describe the diverse barriers to preemptive waitlisting and kidney transplant. The analysis focuses on healthcare system features that particularly disadvantage Black patients, such as the waitlisting eligibility criterion of a single glomerular filtration rate or creatinine clearance ≤20 ml/min, and neglect of wide variation in the rate of progression to end-stage kidney disease (ESKD) in allocating preemptive transplants. We propose initiatives to improve equity including: (1) standardization of waitlisting eligibility criteria related to kidney function; (2) aggressive education for clinicians about early transplant referral; (3) innovations in electronic medical record capabilities; and (4) rapid status 7 listing by centers. If those initiatives fail, the transplant field should consider eliminating preemptive waitlisting and transplantation with deceased donor kidneys.

Effect of Neighborhood Food Environment and Socioeconomic Status on Serum Phosphorus Level for Patients on Chronic Dialysis.

BACKGROUND: Elevated blood phosphorus levels are common and associated with a greater risk of death for patients receiving chronic dialysis. Phosphorus-rich foods are prevalent in the American diet, and low-phosphorus foods, including fruits and vegetables, are often less available in areas with more poverty. The relative contributions of neighborhood food availability and socioeconomic status to phosphorus control in patients receiving dialysis are unknown. METHODS: Using longitudinal data from a national dialysis provider, we constructed hierarchical, linear mixed-effects models to evaluate the relationships between neighborhood food environment or socioeconomic status and serum phosphorus level among patients receiving incident dialysis. RESULTS: Our cohort included 258,510 patients receiving chronic hemodialysis in 2005-2013. Median age at dialysis initiation was 64 years, 45% were female, 32% were Black, and 15% were Hispanic. Within their residential zip code, patients had a median of 25 "less-healthy" food outlets (interquartile range, 11-40) available to them compared with a median of four "healthy" food outlets (interquartile range, 2-6). Living in a neighborhood with better availability of healthy food was not associated with a lower phosphorus level. Neighborhood income also was not associated with differences in phosphorus. Patient age, race, cause of ESKD, and mean monthly dialysis duration were most closely associated with phosphorus level. CONCLUSIONS: Neither neighborhood availability of healthy food options nor neighborhood income was associated with phosphorus levels in patients receiving chronic dialysis. Modifying factors, such as nutrition literacy, individual-level financial resources, and adherence to diet restrictions and medications, may be more powerful contributors than food environment to elevated phosphorus.

National Trends in Utilization and 1-Year Outcomes with Transplantation of HCV-Viremic Kidneys.

BACKGROUND: Recent pilot trials have demonstrated the safety of transplanting HCV-viremic kidneys into HCV-seronegative recipients. However, it remains unclear if allograft function is impacted by donor HCV-viremia or recipient HCV-serostatus. METHODS: We used national United States registry data to examine trends in HCV-viremic kidney use between 4/1/2015 and 3/31/2019. We applied advanced matching methods to compare eGFR for similar kidneys transplanted into highly similar recipients of kidney transplants. RESULTS: Over time, HCV-seronegative recipients received a rising proportion of HCV-viremic kidneys. During the first quarter of 2019, 200 HCV-viremic kidneys were transplanted into HCV-seronegative recipients, versus 69 into HCV-seropositive recipients, while 105 HCV-viremic kidneys were discarded. The probability of HCV-viremic kidney discard has declined over time. Kidney transplant candidates willing to accept a HCV-seropositive kidney increased from 2936 to 16,809 from during this time period. When transplanted into HCV-seronegative recipients, HCV-viremic kidneys matched to HCV-non-viremic kidneys on predictors of organ quality, except HCV, had similar 1-year eGFR (66.3 versus 67.1 ml/min per 1.73 m2, P=0.86). This was despite the much worse kidney donor profile index scores assigned to the HCV-viremic kidneys. Recipient HCV-serostatus was not associated with a clinically meaningful difference in 1-year eGFR (66.5 versus 71.1 ml/min per 1.73 m2, P=0.056) after transplantation of HCV-viremic kidneys. CONCLUSIONS: By 2019, HCV-seronegative patients received the majority of kidneys transplanted from HCV-viremic donors. Widely used organ quality scores underestimated the quality of HCV-viremic kidneys based on 1-year allograft function. Recipient HCV-serostatus was also not associated with worse short-term allograft function using HCV-viremic kidneys.

Leveraging marginal structural modeling with Cox regression to assess the survival benefit of accepting vs declining kidney allograft offers.

Existing studies evaluating the survival benefit of kidney transplantation were unable to incorporate time-updated information on decisions related to each organ offer. We used national registry data, including organ turndown data, to evaluate the survival benefit of accepting vs turning down kidney offers in candidates waitlisted from 2007-2013. Among candidates who declined their first offer, only 43% ultimately received organ transplantations. Recipients who later underwent organ transplantation after declining their first offer had markedly longer wait times than recipients who accepted their first offer, and 56% received kidney transplants that were of similar or lower quality compared to their initial offer. In marginal structural modeling analyses accounting for time-updated offer characteristics (including Kidney Donor Profile Index, Public Health System risk status, and pumping), after 3 months posttransplant, there was a significant survival benefit of accepting an offer (adjusted hazard ratio 0.76, 95% confidence interval 0.66-0.89) that was similar among diabetics, candidates aged >65 years, and candidates living in donor service areas with the longest waitlist times. After carefully accounting for the effect of donor quality, we confirm that the survival benefit of accepting an organ offer is clinically meaningful and persistent beyond 3 months post-kidney transplantation, including high-risk subgroups of organ transplantation candidates.

Association of Kidney Transplant Center Volume With 3-Year Clinical Outcomes.

RATIONALE & OBJECTIVE: A robust relationship between procedure volume and clinical outcomes has been demonstrated across many surgical fields. This study assessed whether a center volume-outcome relationship exists for contemporary kidney transplantation, specifically for diabetic recipients, older recipients (aged ≥65 years), and recipients of high kidney donor profile index (KDPI ≥ 85) kidneys. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: Adult kidney-only transplant recipients who underwent transplantation between 2009 and 2013 (N = 79,581). EXPOSURES: The primary exposure variable was center volume, categorized into quartiles based on the total kidney transplantation volume. Quartile 1 (Q1) centers performed a mean of fewer than 66 kidney transplantations per year, whereas Q4 centers performed a mean of more than 196 kidney transplantations per year. OUTCOMES: All-cause graft failure and mortality within 3 years of transplantation. ANALYTICAL APPROACH: Multivariable Cox frailty models were used to adjust for donor characteristics, recipient characteristics, and cold ischemia time. RESULTS: Minor differences in rates of 3-year deceased donor all-cause graft failure across quartiles of center volume were observed (14.9% for Q1 vs 16.7% for Q4), including in subgroups (diabetic recipients, 18.4% for Q1 vs 19.7% for Q4; older recipients, 19.4% for Q1 vs 22.5% for Q4; recipients of high KDPI kidneys, 26.5% for Q1 vs 26.5% for Q4). Results were similar for 3-year mortality. After adjustment for donor, recipient, and graft characteristics using Cox regression, center volume was not significantly associated with all-cause graft failure or mortality within 3 years, except that diabetic recipients at Q3 centers had slightly lower mortality (compared with Q1 centers, adjusted HR of 0.85 [95% CI, 0.73-0.99]). LIMITATIONS: Potential unmeasured confounding from patient comorbid conditions and organ selection. CONCLUSIONS: These findings provide little evidence that care in higher volume centers is associated with better adjusted outcomes for kidney transplant recipients, even in populations anticipated to be at increased risk for graft failure or death.

Twelve-Month Outcomes After Transplant of Hepatitis C-Infected Kidneys Into Uninfected Recipients: A Single-Group Trial.

Background: Organs from hepatitis C virus (HCV)-infected deceased donors are often discarded. Preliminary data from 2 small trials, including THINKER-1 (Transplanting Hepatitis C kidneys Into Negative KidnEy Recipients), suggested that HCV-infected kidneys could be safely transplanted into HCV-negative patients. However, intermediate-term data on quality of life and renal function are needed to counsel patients about risk. Objective: To describe 12-month HCV treatment outcomes, estimated glomerular filtration rate (eGFR), and quality of life for the 10 kidney recipients in THINKER-1 and 6-month data on 10 additional recipients. Design: Open-label, nonrandomized trial. (ClinicalTrials.gov: NCT02743897). Setting: Single center. Participants: 20 HCV-negative transplant candidates. Intervention: Participants underwent transplant with kidneys infected with genotype 1 HCV and received elbasvir-grazoprevir on posttransplant day 3. Measurements: The primary outcome was HCV cure. Exploratory outcomes included 1) RAND-36 Physical Component Summary (PCS) and Mental Component Summary (MCS) quality-of-life scores at enrollment and after transplant, and 2) posttransplant renal function, which was compared in a 1:5 matched sample with recipients of HCV-negative kidneys. Results: The mean age of THINKER participants was 56.3 years (SD, 6.7), 70% were male, and 40% were black. All 20 participants achieved HCV cure. Hepatic and renal complications were transient or were successfully managed. Mean PCS and MCS quality-of-life scores decreased at 4 weeks; PCS scores then increased above pretransplant values, whereas MCS scores returned to baseline values. Estimated GFRs were similar between THINKER participants and matched recipients of HCV-negative kidneys at 6 months (median, 67.5 vs. 66.2 mL/min/1.73 m2; 95% CI for between-group difference, -4.2 to 7.5 mL/min/1.73 m2) and 12 months (median, 72.8 vs. 67.2 mL/min/1.73 m2; CI for between-group difference, -7.2 to 9.8 mL/min/1.73 m2). Limitation: Small trial. Conclusion: Twenty HCV-negative recipients of HCV-infected kidneys experienced HCV cure, good quality of life, and excellent renal function. Kidneys from HCV-infected donors may be a valuable transplant resource. Primary Funding Source: Merck.

Racial Disparities in Nephrology Consultation and Disease Progression among Veterans with CKD: An Observational Cohort Study.

BACKGROUND: Incident rates of ESRD are much higher among black and Hispanic patients than white patients. Access to nephrology care before progression to ESRD is associated with better clinical outcomes among patients with CKD. However, it is unknown whether black or Hispanic patients with CKD experience lower pre-ESRD nephrology consultation rates compared with their white counterparts, or whether such a disparity contributes to worse outcomes among minorities. METHODS: We assembled a retrospective cohort of patients with CKD who received care through the Veterans Health Administration from 2003 to 2015, focusing on individuals with incident CKD stage 4 who had an initial eGFR≥60 ml/min per 1.73 m2 followed by two consecutive eGFRs<30 ml/min per 1.73 m2. We repeated analyses among individuals with incident CKD stage 3. Outcomes included nephrology provider referral, nephrology provider visit, progression to CKD stage 5, and mortality. RESULTS: We identified 56,767 veterans with CKD stage 4 and 640,704 with CKD stage 3. In both cohorts, rates of nephrology referral and visits were significantly higher among black and Hispanic veterans than among non-Hispanic white veterans. Despite this, both black and Hispanic patients experienced faster progression to CKD stage 5 compared with white patients. Black patients with CKD stage 4 experienced slightly lower mortality than white patients, whereas black patients with CKD stage 3 had a small increased risk of death. CONCLUSIONS: Black or Hispanic veterans with CKD are more likely than white patients to see a nephrologist, yet are also more likely to suffer disease progression. Biologic and environmental factors may play a bigger role than nephrology consultation in driving racial disparities in CKD progression.

Treating hepatitis C infection in patients with advanced CKD in the real world: time to refocus on what our real treatment goals should be.

In this issue, Alric and colleagues demonstrate through real-world experience that grazoprevir-elbasvir is safe and effective for treating hepatitis C in advanced kidney disease patients with higher comorbidity burdens. This commentary highlights that this and similar studies have primarily focused on treatment safety and efficacy, rather than the clinical impact of viral eradication. Critical knowledge gaps including which patients to treat, and when, as well as potential management strategies that may improve outcomes, are discussed.

The case against imminent death donation.

PURPOSE OF REVIEW: Imminent death donation (IDD) is a proposal to procure organs from patients prior to the withdrawal of life support, which is anticipated to lead to death. In this review, we outline substantial concerns that the transplant community should consider when deliberating the possibility of practicing IDD. RECENT FINDINGS: Although there are several compelling theoretical and intuitive reasons to support IDD, its application has been hindered because of inadequate definitions or protocols. A lack of published reports limits empirical data about the practice. Discussion on the topic has not adequately addressed potential harms to the donor, involvement of stakeholders, or the threat to public trust. SUMMARY: Although IDD has been proposed as a method to increase the number of organs or improve end-of-life care, the proposal currently poses more risk than benefit for patients and the transplant community. Until the major barriers to implementation of IDD are addressed, the transplant community should invest its efforts to increase the organ supply elsewhere.

Kidney transplant outcomes for prior living organ donors.

The Organ Procurement and Transplantation Network gives priority in kidney allocation to prior live organ donors who require a kidney transplant. In this study, we analyzed the effect of this policy on facilitating access to transplantation for prior donors who were wait-listed for kidney transplantation in the United States. Using 1:1 propensity score-matching methods, we assembled two matched cohorts. The first cohort consisted of prior organ donors and matched nondonors who were wait-listed during the years 1996-2010. The second cohort consisted of prior organ donors and matched nondonors who underwent deceased donor kidney transplantation. During the study period, there were 385,498 listings for kidney transplantation, 252 of which were prior donors. Most prior donors required dialysis by the time of listing (64% versus 69% among matched candidates; P=0.24). Compared with matched nondonors, prior donors had a higher rate of deceased donor transplant (85% versus 33%; P<0.001) and a lower median time to transplantation (145 versus 1607 days; P<0.001). Prior donors received higher-quality allografts (median kidney donor risk index 0.67 versus 0.90 for nondonors; P<0.001) and experienced lower post-transplant mortality (hazard ratio, 0.19; 95% confidence interval, 0.08 to 0.46; P<0.001) than matched nondonors. In conclusion, these data suggest that prior organ donors experience brief waiting time for kidney transplant and receive excellent-quality kidneys, but most need pretransplant dialysis. Individuals who are considering live organ donation should be provided with this information because this allocation priority will remain in place under the new US kidney allocation system.