The OPTN Deceased Donor Potential Study: Implications for Policy and Practice

Application potential of senolytics in clinical treatment

Of the factors studied in individual ageing, the accumulation of senescent cells has been considered as an essential cause of organ degeneration to eventually initiate age-related diseases. Cellular senescence is attributed to the accumulation of damage for an inducement in the activation of cell cycle inhibitory pathways, resulting the cell permanently withdraw from the cell proliferation cycle. Further, senescent cells will activate the inflammatory factor secretion pathway to promote the development of various age-related diseases. Senolytics, a small molecule compound, can delay disease development and extend mammalian lifespan. The evidence from multiple trials shows that the targeted killing of senescent cells has a significant clinical application for the treatment of age-related diseases. In addition, senolytics are also significant for the development of ageing research in solid organ transplantation, which can fully develop the potential of elderly organs and reduce the age gap between demand and supply. We conclude that the main characteristics of cellular senescence, the anti-ageing drug senolytics in the treatment of chronic diseases and organ transplantation, and the latest clinical progress of related researches in order to provide a theoretical basis for the prevention and treatment of ageing and related diseases.

Donor heart refusal after circulatory death: An analysis of United Network for Organ Sharing refusal codes

Objective

Donor hearts procured after circulatory death (DCD) may significantly increase the number of hearts available for transplantation. The purpose of this study was to analyze current DCD and brain-dead donor (DBD) heart transplantation rates and characterize organ refusal using the most up-to-date United Network for Organ Sharing (UNOS) and Organ Procurement and Transplantation Network data.

Methods

We analyzed UNOS and Organ Procurement and Transplantation Network DBD and DCD candidate, transplantation, and demographic data from 2020 through 2022 and 2022 refusal code data to characterize DCD heart use and refusal. Subanalyses were performed to characterize DCD donor demographics and regional transplantation rate variance.

Results

DCD hearts were declined 3.37 times more often than DBD hearts. The most frequently used code for DCD refusal was neurologic function, related to concerns of a prolonged dying process and organ preservation. In 2022, 92% (1329/1452) of all DCD refusals were attributed to neurologic function. When compared with DBD, DCD donor hearts were more frequently declined as the result of prolonged warm ischemic time (odds ratio, 5.65; 95% confidence interval, 4.07-7.86) and other concerns over organ preservation (odds ratio, 4.06; 95% confidence interval, 3.33-4.94). Transplantation rate variation was observed between demographic groups and UNOS regions. DCD transplantation rates are currently experiencing second order polynomial growth.

Conclusions

DCD donor hearts are declined more frequently than DBD. DCD heart refusals result from concerns over a prolonged dying process and organ preservation. Heart transplantation rates may be substantially improved by ex situ hemodynamic assessment, adoption of normothermic regional perfusion guidelines, and quality initiatives.

Transmission and Non-transmission of Melanoma From Deceased Solid Organ Donors to Transplant Recipients: Risks and Missed Opportunities

BACKGROUND

Biovigilance concerns are in tension with the need to increase organ donation. Cancer transmission risk from donor to recipient may be overestimated, as non-transmission events are rarely reported. We sought to estimate melanoma transmission risk in deceased organ donation and identify missed opportunities for donation in an Australian cohort with high melanoma prevalence.

METHODS

We used a population-based approach and linked deceased organ donors, transplant recipients, and potential donors forgone, 2010-2018, with the Central Cancer Registry (CCR), 1976-2018. We identified melanomas using ICD-O-3 classification, assessed the probability of transmission, and compared suspected melanoma history in potential donors forgone with melanoma notifications in the CCR.

RESULTS

There were 9 of 993 donors with melanoma in CCR; 4 in situ low-risk and 5 invasive high-to-unacceptable risk. Four were unrecognized before donation. Of 16 transplant recipients at risk, we found 0 of 14 transmission events (2 recipients had insufficient follow-up). Of 35 of 3588 potential donors forgone for melanoma risk alone, 17 were otherwise suitable for donation; 6 of 35 had no melanoma in CCR, 2 of 35 had in situ melanomas and 9 of 35 had thin invasive melanomas (localized, ≤0.8 mm thickness).

CONCLUSIONS

Our findings contribute to current evidence that suggests donors with melanomas of low metastatic potential may provide an opportunity to safely increase organ donation and so access to transplantation.

Aging exacerbates murine lung ischemia-reperfusion injury by excessive inflammation and impaired tissue repair response

Donor shortage is a major problem in lung transplantation (LTx), and the use of lungs from elderly donors is one of the possible solutions in a rapidly aging population. However, the utilization of organs from donors aged >65 years has remained infrequent and may be related to a poor outcome. To investigate the molecular events in grafts from elderly donors early after LTx, the left lungs of young and old mice were subjected to 1 hour of ischemia and subsequent reperfusion. The left lungs were collected at 1 hour, 1 day, and 3 days after reperfusion and subjected to wet-to-dry weight ratio measurement, histological analysis, and molecular biological analysis, including RNA sequencing. The lungs in old mice exhibited more severe and prolonged pulmonary edema than those in young mice after ischemia reperfusion, which was accompanied by upregulation of the genes associated with inflammation and impaired expression of cell cycle-related genes. Apoptotic cells increased and proliferating type 2 alveolar epithelial cells decreased in the lungs of old mice compared with young mice. These factors could become conceptual targets for developing interventions to ameliorate lung ischemia-reperfusion injury after LTx from elderly donors, which may serve to expand the old donor pool.

Geographic disparities in access to liver transplantation

Since the Final Rule regarding transplantation was published in 1999, organ distribution policies have been implemented to reduce geographic disparity. While a recent change in liver allocation, termed acuity circles, eliminated the donor service area as a unit of distribution to decrease the geographic disparity of waitlisted patients to liver transplantation, recently published results highlight the complexity of addressing geographic disparity. From geographic variation in donor supply, as well as liver disease burden and differing model for end-stage liver disease (MELD) scores of candidates and MELD scores necessary to receive liver transplantation, to the urban-rural disparity in specialty care access, and to neighborhood deprivation (community measure of socioeconomic status) in liver transplant access, addressing disparities of access will require a multipronged approach at the patient, transplant center, and national level. Herein, we review the current knowledge of these disparities-from variation in larger (regional) to smaller (census tract or zip code) levels to the common etiologies of liver disease, which are particularly affected by these geographic boundaries. The geographic disparity in liver transplant access must balance the limited organ supply with the growing demand. We must identify patient-level factors that contribute to their geographic disparity and incorporate these findings at the transplant center level to develop targeted interventions. We must simultaneously work at the national level to standardize and share patient data (including socioeconomic status and geographic social deprivation indices) to better understand the factors that contribute to the geographic disparity. The complex interplay between organ distribution policy, referral patterns, and variable waitlisting practices with the proportion of high MELD patients and differences in potential donor supply must all be considered to create a national policy strategy to address the inequities in the system.

Variability in Heart Yield From Donation After Brain Death Between Organ Procurement Organizations: An Opportunity for Improvement

Increasing the number of available hearts for transplantation is the best strategy to decrease waitlist mortality. This study examines organ procurement organizations (OPOs) and their role in the transplantation network to determine whether variability in performance exists across them. Adult deceased donors who met the criteria for brain death between 2010 and 2020 (inclusive) in the United States were examined. A regression model was fitted and internally validated using donor characteristics available at the time of organ recovery to predict the likelihood of heart transplantation. Subsequently, an expected heart yield was calculated for each donor using this model. Observed-to-expected (O/E) heart yield ratios for each OPO were calculated by dividing the number of hearts recovered for transplantation by the expected number of recoveries. There were 58 OPOs active during the study period, and on average, OPO activity grew over time. The mean O/E ratio among OPOs was 0.98 (standard deviation ± 0.18). Twenty-one OPOs consistently performed below the expected level (95% confidence intervals < 1.0) and generated a deficit of 1,088 expected transplantations during the study period. The proportion of hearts that were recovered for transplantation varied significantly by OPO categories: low tier 31.8%, mid tier 35.6%, and high tier 36.2% (p < 0.01), even as the expected yield was similar across tiers (p = 0.69). OPO performance accounts for 28% of the variability in successfully transplanting a heart after accounting for the role of referring hospitals, donor families, and transplantation centers. In conclusion, there is significant variability in volume and heart yield from brain-dead donors across OPOs.

Variability in Organ Procurement Organization Performance by Individual Hospital in the United States

Importance

Availability of organs inadequately addresses the need of patients waiting for a transplant.

Objective

To estimate the true number of donor patients in the United States and identify inefficiencies in the donation process as a way to guide system improvement.

Design, Setting, and Participants

A retrospective cross-sectional analysis was performed of organ donation across 13 different hospitals in 2 donor service areas covered by 2 organ procurement organizations (OPOs) in 2017 and 2018 to compare donor potential to actual donors. More than 2000 complete medical records for decedents were reviewed as a sample of nearly 9000 deaths. Data were analyzed from January 1, 2017, to December 31, 2018.

Exposure

Deaths of causes consistent with donation according to medical record review, ventilated patient referrals, center acceptance practices, and actual deceased donors.

Main Outcomes and Measures

Potential donors by medical record review vs actual donors and OPO performance at specific hospitals.

Results

Compared with 242 actual donors, 931 potential donors were identified at these hospitals. This suggests a deceased donor potential of 3.85 times (95% CI, 4.23-5.32) the actual number of donors recovered. There was a surprisingly wide variability in conversion of potential donor patients into actual donors among the hospitals studied, from 0% to 51.0%. One OPO recovered 18.8% of the potential donors, whereas the second recovered 48.2%. The performance of the OPOs was moderately related to referrals of ventilated patients and not related to center acceptance practices.

Conclusions and Relevance

In this cross-sectional study of hospitals served by 2 OPOs, wide variation was found in the performance of the OPOs, especially at individual hospitals. Addressing this opportunity could greatly increase the organ supply, affirming the importance of recent efforts from the federal government to increase OPO accountability and transparency.

Cryopreservation of Whole Rat Livers by Vitrification and Nanowarming

Liver cryopreservation has the potential to enable indefinite organ banking. This study investigated vitrification-the ice-free cryopreservation of livers in a glass-like state-as a promising alternative to conventional cryopreservation, which uniformly fails due to damage from ice formation or cracking. Our unique "nanowarming" technology, which involves perfusing biospecimens with cryoprotective agents (CPAs) and silica-coated iron oxide nanoparticles (sIONPs) and then, after vitrification, exciting the nanoparticles via radiofrequency waves, enables rewarming of vitrified specimens fast enough to avoid ice formation and uniformly enough to prevent cracking from thermal stresses, thereby addressing the two main failures of conventional cryopreservation. This study demonstrates the ability to load rat livers with both CPA and sIONPs by vascular perfusion, cool them rapidly to an ice-free vitrified state, and rapidly and homogenously rewarm them. While there was some elevation of liver enzymes (Alanine Aminotransferase) and impaired indocyanine green (ICG) excretion, the nanowarmed livers were viable, maintained normal tissue architecture, had preserved vascular endothelium, and demonstrated hepatocyte and organ-level function, including production of bile and hepatocyte uptake of ICG during normothermic reperfusion. These findings suggest that cryopreservation of whole livers via vitrification and nanowarming has the potential to achieve organ banking for transplant and other biomedical applications.

Predicting older-donor kidneys' post-transplant renal function using pre-transplant data

This paper provides a methodology for predicting post-transplant kidney function, that is, the 1-year post-transplant estimated Glomerular Filtration Rate (eGFR-1) for each donor-candidate pair. We apply customized machine-learning algorithms to pre-transplant donor and recipient data to determine the probability of achieving an eGFR-1 of at least 30 ml/min. This threshold was chosen because there is insufficient survival benefit if the kidney fails to generate an eGFR-1 ≥ 30 ml/min. For some donor-candidate pairs, the developed algorithm provides highly accurate predictions. For others, limitations of previous transplants' data results in noisier predictions. However, because the same kidney is offered to many candidates, we identify those pairs for whom the predictions are highly accurate. Out of 6977 discarded older-donor kidneys that were a match with at least one transplanted kidney, 5282 had one or more identified candidate, who were offered that kidney, did not accept any other offer, and would have had ≥80% chance of achieving eGFR-1 ≥ 30 ml/min, had the kidney been transplanted. We also show that transplants with ≥80% chance of achieving eGFR-1 ≥ 30 ml/min and that survive 1 year have higher 10-year death-censored graft survival probabilities than all older-donor transplants that survive 1 year (73.61% vs. 70.48%, respectively).

Maximizing the use of potential donors through increased rates of family approach for authorization

In the United States, a small proportion of potential deceased organ donor referrals lead to donation and recovery. Understanding variation in the processes involved between organ procurement organizations (OPOs) may help increase deceased donation and reduce the organ shortage. We studied 103 923 referrals from 10 OPOs from 2018 to 2019, of which 14.4% led to approach for authorization, 8.2% led to authorization, 5.1% led to organ recovery, and 4.8% led to transplantation. First-person authorization (FPA) was associated with threefold higher odds of donation (OR = _2.83 3.02 _3.22 , p < .001). Female referrals had 11% lower odds of approach; when approached, Black and Hispanic referrals had 46% and 35% lower odds of authorization, respectively (all p < .001). There was substantial OPO-level variation in rates of approach, authorization, and organ recovery, which persisted after adjusting for age, sex, race, and FPA status. An OPO's relative rate of approach correlated strongly with its relative rate of donation among all referrals (ρ = 0.43). Correlation between an individual OPO's authorization rate among approached families, and overall rate of donation, was negative, suggesting that high authorization rates may be the result of selective approach practices. Therefore, approaching a higher proportion of families for authorization may lead to higher donation rates.

Preserving and rejuvenating old organs for transplantation: novel treatments including the potential of senolytics

PURPOSE OF REVIEW

Older donors have the potential to close the gap between demand and supply in solid organs transplantation. Utilizing older organs, at the same time, has been associated with worse short- and long-term outcomes. Here, we introduce potential mechanisms on how treatments during machine perfusion (MP) may safely improve the utilization of older organs.

RECENT FINDINGS

Consequences of ischemia reperfusion injury (IRI), a process of acute, sterile inflammation leading to organ injury are more prominent in older organs. Of relevance, organ age and IRI seem to act synergistically, leading to an increase of damage associated molecular patterns that trigger innate and adaptive immune responses. While cold storage has traditionally been considered the standard of care in organ preservation, accumulating data support that both hypothermic and normothermic MP improve organ quality, particularly in older organs. Furthermore, MP provides the opportunity to assess the quality of organs while adding therapeutic agents. Experimental data have already demonstrated the potential of applying treatments during MP. New experimental show that the depletion of senescent cells that accumulate in old organs improves organ quality and transplant outcomes.

SUMMARY

As the importance of expanding the donor pool is increasing, MP and novel treatments bear the potential to assess and regenerate older organs, narrowing the gap between demand and supply.

Primary Graft Dysfunction: The Role of Aging in Lung Ischemia-Reperfusion Injury

Transplant centers around the world have been using extended criteria donors to remedy the ongoing demand for lung transplantation. With a rapidly aging population, older donors are increasingly considered. Donor age, at the same time has been linked to higher rates of lung ischemia reperfusion injury (IRI). This process of acute, sterile inflammation occurring upon reperfusion is a key driver of primary graft dysfunction (PGD) leading to inferior short- and long-term survival. Understanding and improving the condition of older lungs is thus critical to optimize outcomes. Notably, ex vivo lung perfusion (EVLP) seems to have the potential of reconditioning ischemic lungs through ex-vivo perfusing and ventilation. Here, we aim to delineate mechanisms driving lung IRI and review both experimental and clinical data on the effects of aging in augmenting the consequences of IRI and PGD in lung transplantation.

Impact of Portable Normothermic Blood-Based Machine Perfusion on Outcomes of Liver Transplant: The OCS Liver PROTECT Randomized Clinical Trial

Question

Can oxygenated portable normothermic perfusion of deceased donor livers for transplant improve outcomes compared with the current standard of care using ischemic cold storage?

Findings

In this multicenter randomized clinical trial of 300 recipients of liver transplants with the donor liver preserved by either normothermic perfusion or conventional ischemic cold storage, normothermic machine perfusion resulted in decreased early liver graft injury and ischemic biliary complications and greater organ utilization.

Meaning

In this study, portable normothermic oxygenated machine perfusion of donor liver grafts resulted in improved outcomes after liver transplant and in more livers being transplanted.

Importance

Ischemic cold storage (ICS) of livers for transplant is associated with serious posttransplant complications and underuse of liver allografts.

Objective

To determine whether portable normothermic machine perfusion preservation of livers obtained from deceased donors using the Organ Care System (OCS) Liver ameliorates early allograft dysfunction (EAD) and ischemic biliary complications (IBCs).

Design, Setting, and Participants

This multicenter randomized clinical trial (International Randomized Trial to Evaluate the Effectiveness of the Portable Organ Care System Liver for Preserving and Assessing Donor Livers for Transplantation) was conducted between November 2016 and October 2019 at 20 US liver transplant programs. The trial compared outcomes for 300 recipients of livers preserved using either OCS (n = 153) or ICS (n = 147). Participants were actively listed for liver transplant on the United Network of Organ Sharing national waiting list.

Interventions

Transplants were performed for recipients randomly assigned to receive donor livers preserved by either conventional ICS or the OCS Liver initiated at the donor hospital.

Main Outcomes and Measures

The primary effectiveness end point was incidence of EAD. Secondary end points included OCS Liver ex vivo assessment capability of donor allografts, extent of reperfusion syndrome, incidence of IBC at 6 and 12 months, and overall recipient survival after transplant. The primary safety end point was the number of liver graft–related severe adverse events within 30 days after transplant.

Results

Of 293 patients in the per-protocol population, the primary analysis population for effectiveness, 151 were in the OCS Liver group (mean [SD] age, 57.1 [10.3] years; 102 [67%] men), and 142 were in the ICS group (mean SD age, 58.6 [10.0] years; 100 [68%] men). The primary effectiveness end point was met by a significant decrease in EAD (27 of 150 [18%] vs 44 of 141 [31%]; P = .01). The OCS Liver preserved livers had significant reduction in histopathologic evidence of ischemia-reperfusion injury after reperfusion (eg, less moderate to severe lobular inflammation: 9 of 150 [6%] for OCS Liver vs 18 of 141 [13%] for ICS; P = .004). The OCS Liver resulted in significantly higher use of livers from donors after cardiac death (28 of 55 [51%] for the OCS Liver vs 13 of 51 [26%] for ICS; P = .007). The OCS Liver was also associated with significant reduction in incidence of IBC 6 months (1.3% vs 8.5%; P = .02) and 12 months (2.6% vs 9.9%; P = .02) after transplant.

Conclusions and Relevance

This multicenter randomized clinical trial provides the first indication, to our knowledge, that normothermic machine perfusion preservation of deceased donor livers reduces both posttransplant EAD and IBC. Use of the OCS Liver also resulted in increased use of livers from donors after cardiac death. Together these findings indicate that OCS Liver preservation is associated with superior posttransplant outcomes and increased donor liver use.

Trial Registration

ClinicalTrials.gov Identifier: NCT02522871

The potential of Senolytics in transplantation

Older organs provide a substantial unrealized potential with the capacity to close the gap between demand and supply in organ transplantation. The potential of senolytics in improving age-related conditions has been shown in various experimental studies and early clinical trials. Those encouraging data may also be of relevance for transplantation. As age-differences between donor and recipients are not uncommon, aging may be accelerated in recipients when transplanting older organs; young organs may, at least in theory, have the potential to 'rejuvenate' old recipients. Here, we review the relevance of senescent cells and the effects of senolytics on organ quality, alloimmune responses and outcomes in solid organ transplantation. This article is part of the Special Issue - Senolytics - Edited by Joao Passos and Diana Jurk.

Reexamining Risk Aversion: Willingness to Pursue and Utilize Nonideal Donor Livers Among US Donation Service Areas

Background

Livers from "nonideal" but acceptable donors are underutilized; however, organ procurement organization (OPO) metrics do not assess how OPO-specific practices contribute to these trends. In this analysis, we evaluated nonideal liver donor avoidance or risk aversion among OPOs and within US donation service areas (DSAs).

Methods

Adult donors in the United Network for Organ Sharing registry who donated ≥1 organ for transplantation between 2007 and 2019 were included. Nonideal donors were defined by any of the following: age > 70, hepatitis C seropositive, body mass index > 40, donation after circulatory death, or history of malignancy. OPO-specific performance was evaluated based on rates of nonideal donor pursuit and consent attainment. DSA performance (OPO + transplant centers) was evaluated based on rates of nonideal donor pursuit, consent attainment, liver recovery, and transplantation. Lower rates were considered to represent increased donor avoidance or increased risk aversion.

Results

Of 97 911 donors, 31 799 (32.5%) were nonideal. Unadjusted OPO-level rates of nonideal donor pursuit ranged from 88% to 100%. In a 5-tier system of overall risk aversion, tier 5 DSAs (least risk-averse) and tier 1 DSAs (most risk-averse) had the highest and lowest respective rates of non-ideal donor pursuit, consent attainment, liver recovery, and transplantation. On average, recovery rates were over 25% higher among tier 5 versus tier 1 DSAs. If tier 1 DSAs had achieved the same average liver recovery rate as tier 5 DSAs, approximately 2100 additional livers could have been recovered during the study period.

Conclusion

Most OPOs aggressively pursue nonideal liver donors; however, recovery practices vary widely among DSAs. Fair OPO evaluations should consider early donation process stages to best disentangle OPO and center-level practices.

Aggressive pursuit and utilization of non-ideal donor lungs does not compromise post-lung transplant survival

BACKGROUND

Organ procurement organizations (OPOs) vary in willingness to pursue and utilize non-ideal donor lungs; implications of these practices for lung transplant (LTx) recipients remain unclear. We examined associations between OPO-level behavior toward non-ideal donors and post-LTx outcomes.

METHODS

Adult lung donors and corresponding adult first-time LTx recipients in the 2008-2019 UNOS registry were included. Non-ideal donors had any of age > 50, smoking history ≥20 pack-years, PaO₂ /FiO₂ ratio ≤350, donation after circulatory death, or increased risk status. OPOs were classified as least, moderately, or most aggressive based on non-ideal donor pursuit, consent attainment, lung recovery, and transplantation. Post-transplant outcomes were compared among aggressiveness strata.

RESULTS

Of 22,795 recipients, 6229 (27.3%), 8256 (36.2%), and 8310 (36.5%) received lungs from least, moderately, and most aggressive OPOs, respectively. Moderately aggressive OPOs had the highest recipient rates of pre-discharge acute rejection, grade 3 primary graft dysfunction, postoperative extracorporeal membrane oxygenation, and longest lengths of stay. After adjustment, moderately and most aggressive OPOs had similar risks of recipient mortality as least aggressive OPOs.

CONCLUSIONS

The most and least aggressive OPOs achieve similar patient survival and short-term post-LTx outcomes. Aggressive pursuit and utilization of non-ideal donor lungs by less aggressive OPOs would likely expand the donor pool, without compromising recipient outcomes.

Systematic review on potential brain dead donor estimations and conversion rates to actually realized organ donations

INTRODUCTION

Accurate estimations of potential organ donors (POTDs) are required to improve transplant systems. This systematic review analyses current studies on national estimations of potential donors for transplantation as well as the practical and policy implications of detected differences.

METHOD

A systematic review of literature published between 01.01.2010 and 01.04.2020 in PubMed was conducted. Data was extracted into a self-developed matrix, and further data retrieved on national population sizes, waiting lists and transplant activities.

RESULTS

Six studies were included. Investigated populations, underlying data collections and eligibility criteria for POTDs varied widely. Estimated POTDs per million population (p.m.p.) ranged from 25.8 to 333.6, conversion rates from 3.2% to 47.5% leading to 41.2 to 86.4 transplanted organs p.m.p.. Patients on the waiting lists varied from 66.7 to 338.9 p.m.p., defining gaps between organ supply and demand in countries. Not all studies adhered to the definitions and processes of the critical pathway for deceased donation which is the latest international consensus statement on deceased organ donation.

CONCLUSION

Differences in estimated POTDs and differences in supply and demand of donor organs between countries cannot be satisfactorily explained yet due to an obvious lack of evidence, consistent methodology, international consensus and robust underlying datasets. Future studies should be based on robust underlying data sets and aim for potential donor estimations that allow national comparisons due to the adherence to the international consensus on definitions, processes and methodology.

Results of a data-driven performance improvement initiative in organ donation

New metrics for organ procurement organization (OPO) performance utilize National Center for Health Statistics data to measure cause, age, and location consistent (CALC) deaths. We used this denominator to identify opportunities for improved donor conversion at one OPO, Indiana Donor Network (INOP). We sought to determine whether such analyses are immediately actionable for quality improvement (QI) initiatives directed at increased donor conversion. CALC-based assessment of INOP's performance revealed an opportunity to improve conversion of older donors. Following the QI initiative, INOP donor yield rose by 44%, while organs transplanted rose by 29%. These changes tolerated temporary disruption around the COVID-19 pandemic. Improved donor yield was primarily seen in older groups identified by CALC-based methods. Process changes in resource allocation and monitoring were associated with a 57% increase in the number of potential donors approached in the QI period and a subsequent rise in the number of potential donor referrals, suggesting positive feedback at area hospitals. Post-intervention, INOP's projected donation performance rose from 51st to 18th among all OPOs. OPOs can use CALC death data to accurately assess donor conversion by categories including age and race/ethnicity. These data can be used in real time to inform OPO-level processes to maximize donor recovery.

US deceased kidney transplantation: Estimated GFR, donor age and KDPI association with graft survival

BACKGROUND

Despite a significant shortage of kidneys for transplantation in the US, kidneys from older deceased donors are infrequently transplanted. This is primarily over concern of graft quality and transplant durability.

METHODS

The US national transplant database (2000-2018) was assessed for deceased donor kidney transplant patient and graft survival, graft durability and stratified by donor age (<65 years>), Kidney Donor Profile Index (KDPI) and estimated glomerual filtration rate (GFR) one year post-transplantation (eGFR-1) were calculated.

FINDINGS

Recipients of kidneys transplanted from deceased donors >65 years had a lower eGFR-1, (median 39 ml/min) than recipients of younger donor kidneys (median 54 ml/min). However, death-censored graft survival, stratified by eGFR-1, demonstrated similar survival, irrespective of donor age or KDPI. The durability of kidney survival decreases as the achieved eGFR-1 declines. KDPI has a poor association with eGFR-1 and lesser for graft durability. While recipients of kidneys > 65 years had a higher one year mortality than younger kidney recipients, recipients of kidneys > 65 years and an eGFR-1 <30 ml/min, had a lower survival than an untransplanted waitlist cohort (p<0.001).

INTERPRETATION

The durability of kidney graft survival after transplantation was associated with the amount of kidney function gained through the transplant (eGFR-1) and the rate of graft loss (return to dialysis) was not significantly associated with donor age. 24.9% of recipients of older donor kidneys failed to achieve sufficient eGFR-1 providing a transplant survival benefit. While there is significant benefit from transplanting older kidneys, better decision-making tools are required to avoid transplanting kidneys that provide insufficient renal function.

FUNDING

None.

Donation after circulatory death liver transplantation: An in-depth analysis and propensity score-matched comparison

BACKGROUND

Careful donor-recipient matching and reduced ischemia times have improved outcomes following donation after circulatory death (DCD) liver transplantation (LT). This study examines a single-center experience with DCD LT including high-acuity and hospitalized recipients.

METHODS

DCD LT outcomes were compared to a propensity score-matched (PSM) donation after brain death (DBD) LT cohort (1:4); 32 DCD LT patients and 128 PSM DBD LT patients transplanted from 2008 to 2018 were included. Analyses included Kaplan-Meier estimates and Cox proportional hazards models examining patient and graft survival.

RESULTS

Median MELD score in the DCD LT cohort was 22, with median MELD of 27 for DCD LT recipients with decompensated cirrhosis. No difference in mortality or graft loss was found (p < .05) between DCD LT and PSM DBD LT at 3 years post-transplant, nor was DCD an independent risk factor for patient or graft survival. Post-LT severe acute kidney injury was similar in both groups. Ischemic-type biliary lesions (ITBL) occurred in 6.3% (n = 2) of DCD LT recipients, resulting in 1 graft loss and 1 death.

CONCLUSION

This study supports that DCD LT outcomes can be similar to DBD LT, with a low rate of ITBL, in a cohort including high-acuity recipients. Strict donor selection criteria, ischemia time minimization, and avoiding futile donor/recipient combinations are essential considerations.

Changing Trends in Liver Transplantation: Challenges and Solutions

Despite improvements in postliver transplant outcomes through refinements in perioperative management and surgical techniques, several changing trends in liver transplantation have presented challenges. Mortality on the waitlist remains high. In the United States, Europe, and the United Kingdom, there is an increasing need for liver transplantation, primarily as a result of increased incidence of nonalcoholic steatohepatitis-related cirrhosis and cancer indications. Meanwhile, donor suitability has decreased, as donors are often older and have more comorbidities. Despite a mismatch between organ need and availability, many organs are discarded. Notwithstanding this, many solutions have been developed to overcome these challenges. Innovative techniques in allograft preservation, viability assessment, and reconditioning have allowed the use of suboptimal organs with adequate results. Refinements in surgical procedures, including live donor liver transplantations, have increased the organ pool and are decreasing the time and mortality on the waitlist. Despite many challenges, a similar number of solutions and prospects are on the horizon. This review seeks to explore the changing trends and challenges in liver transplantation and highlight possible solutions and future directions.

Transplantation of liver from hepatitis C-infected donors to hepatitis C RNA-negative recipients: Histological and virologic outcome

BACKGROUND

The virologic and histologic outcomes of a hepatitis C virus (HCV)-infected liver graft into an HCV-negative recipient are not well understood. We aimed to evaluate the sustained virologic response (SVR) rate and the liver histology at 1 year post-Orthotopic liver transplantation (OLT) with an HCV-infected graft.

METHODS

A total of 33 patients received the HCV antibody (Ab)+/nucleic acid amplification test (NAT)+ graft. Of these patients, 23 were HCV-negative recipients and 10 were HCV-positive recipients. The 1-year biopsy data were available for 24 patients: 15 patients in HCV-negative group who received an HCV Ab+/NAT+graft and 9 patients in HCV-positive group who received an HCV Ab+/NAT+ graft. Patients with (+) HCV ribonucleic acid (RNA) were started on direct-acting antiviral (DAA) treatment approximately 107 days after OLT using either a Glecaprevir-Pibrentasvir or Sofosbuvir-Velpatasvir or Sofosbuvir-Ledipasvir.

RESULTS

All patients (n = 33) were treated with DAA and achieved SVR. The 1-year post-OLT liver biopsies were available in 24 patients: 9 patients had F1 and F2 fibrosis and 17 patients had minimal to moderate inflammation. There was no statistical difference in fibrosis and inflammation between the HCV-negative vs. HCV-positive recipients. All patients who received the NAT+ graft developed viremia and subsequently achieved SVR with treatment.

CONCLUSION

At 1 year protocol liver biopsy, patients had inflammation consistent with viral hepatitis despite the successful eradication of HCV.

Estimated impact of novel coronavirus-19 and transplant center inactivity on end-stage renal disease-related patient mortality in the United States

To predict whether the COVID‐19 pandemic and transplant center responses could have resulted in preventable deaths, we analyzed registry information of the US end‐stage renal disease (ESRD) patient population awaiting kidney transplantation. Data were from the Organ Procurement and Transplantation Network (OPTN), the US Centers for Disease Control and Prevention, and the United States Renal Data System. Based on 2019 OPTN reports, annualized reduction in kidney transplantation of 25%–100% could result in excess deaths of wait‐listed (deceased donor) transplant candidates from 84 to 337 and living donor candidate excess deaths from 35 to 141 (total 119–478 potentially preventable deaths of transplant candidates). Changes in transplant activity due to COVID‐19 varied with some centers shutting down while others simply heeded known or suspected pandemic risks. Understanding potential excess mortality for ESRD transplant candidates when circumstances compel curtailment of transplant activity may inform policy and procedural aspects of organ transplant systems allowing ways to best inform patients and families as to potential risks in shuttering organ transplant activity. Considering that more than 700 000 Americans have ESRD with 100 000 awaiting a kidney transplant, our highest annual estimate of 478 excess total deaths from postponing kidney transplantation seems modest.

A three-tier system for evaluation of organ procurement organizations' willingness to pursue and utilize nonideal donor lungs

Lungs from "nonideal," but acceptable donors are underutilized; however, organ procurement organization (OPO) metrics do not reflect the extent to which OPO-specific practices contribute to these trends. We developed a comprehensive system to evaluate nonideal lung donor avoidance, or risk aversion among OPOs. Adult donors in the UNOS registry who donated ≥1 organ for transplantation between 2007 and 2018 were included. Nonideal donors had any of age>50, smoking history ≥20 pack-years, PaO₂ /FiO₂ ratio ≤350, donation after circulatory death, or increased risk status. OPO-level risk aversion in donor pursuit, consent attainment, lung recovery, and transplantation was assessed. Among 83916 donors, 70372 (83.9%) were nonideal. Unadjusted OPO-level rates of nonideal donor pursuit ranged from 81 to 100%. In a three-tier system of overall risk aversion, tier 3 OPOs (least risk-averse) had the highest rates of nonideal donor pursuit, consent attainment, lung recovery, and transplantation. Tier 1 OPOs (most risk-averse) had the lowest rates of donor pursuit, consent attainment, and lung recovery, but higher rates of transplantation compared to tier 2 OPOs (moderately risk-averse). Risk aversion varies among OPOs and across the donation process. OPO evaluations should reflect early donation process stages to best differentiate over- and underperforming OPOs and encourage optimal OPO-specific performance.

Cancer as a System Dysfunction

In this paper, we describe a system dynamics model that views cancer as a dysfunction of the cellular system rather than as an ailment of cells. Our experiments with the model replicate the propagation of the ailment and the impacts of the treatments. It presents a concept that deviates from the pervasive view of cancer as a cell malfunction that has led to treatments aiming to destroy the rogue cells. It points to more holistic treatment options aiming at reforming cell interaction so the system can contain the growth of cancer cells. Further research is needed to explore the details for such options.

Cost-effectiveness of using hepatitis C viremic hearts for transplantation into HCV-negative recipients

Outcomes following hepatitis C virus (HCV)-viremic heart transplantation into HCV-negative recipients with HCV treatment are good. We assessed cost-effectiveness between cohorts of transplant recipients willing and unwilling to receive HCV-viremic hearts. Markov model simulated long-term outcomes among HCV-negative patients on the transplant waitlist. We compared costs (2018 USD) and health outcomes (quality-adjusted life-years, QALYs) between cohorts willing to accept any heart and those willing to accept only HCV-negative hearts. We assumed 4.9% HCV-viremic donor prevalence. Patients receiving HCV-viremic hearts were treated, assuming $39 600/treatment with 95% cure. Incremental cost-effectiveness ratios (ICERs) were compared to a $100 000/QALY gained willingness-to-pay threshold. Sensitivity analyses included stratification by blood type or region and potential negative consequences of receipt of HCV-viremic hearts. Compared to accepting only HCV-negative hearts, accepting any heart gained 0.14 life-years and 0.11 QALYs, while increasing costs by $9418/patient. Accepting any heart was cost effective (ICER $85 602/QALY gained). Results were robust to all transplant regions and blood types, except type AB. Accepting any heart remained cost effective provided posttransplant mortality and costs among those receiving HCV-viremic hearts were not >7% higher compared to HCV-negative hearts. Willingness to accept HCV-viremic hearts for transplantation into HCV-negative recipients is cost effective and improves clinical outcomes.

Transplant Center Variability in Organ Offer Acceptance and Mortality Among US Patients on the Heart Transplant Waitlist

Importance

Under the current Centers for Medicare & Medicaid Services guidelines, there is incentivization to optimize posttransplant outcomes regardless of mortality among patients on the waitlist and transplant rates; few data exist with regard to transplant center acceptance practices and survival to heart transplant.

Objectives

To evaluate the extent of variability in organ acceptance practices in the US and whether this center-level behavior is associated with heart transplant candidate survival.

Design, Setting, and Participants

In this retrospective cohort study, the US National Transplant Registry was queried for all match runs of adult candidates listed for isolated heart transplant between May 1, 2007, and March 31, 2017. Data analysis was conducted from October 30, 2018, to May 1, 2019. The final cohort included 93 transplant centers, 19 703 donors, and 9628 candidates.

Main Outcomes and Measures

Center acceptance rates for heart allografts offered to the highest-priority candidates, association between center acceptance rate and mortality among patients on the waitlist, and posttransplant outcomes between candidates who accepted their first-rank offers vs those who accepted previously declined offers.

Results

Among 19 703 unique organ offers, 6302 hearts (32.0%) were accepted for first-rank candidates. After adjustment for donor, candidate, and geographic covariates, transplant centers varied in acceptance rates (12.3%-61.5%) of offers made to first-rank candidates. Higher acceptance rates were associated with lower cumulative incidence of 1-year mortality among patients on the waitlist. For every 10% increase in adjusted center acceptance rate, the risk of mortality decreased by 27% (subdistribution hazard ratio, 0.73; 95% CI, 0.67-0.80). No statistically significant difference was observed in 5-year adjusted posttransplant patient survival (adjusted hazard ratio, 1.02; 95% CI, 0.94-1.11) and graft failure (subdistribution hazard ratio; 0.95; 95% CI, 0.83-1.09) between hearts accepted at the first-rank compared with lower-rank positions.

Conclusions and Relevance

Variability in heart allograft acceptance rates appears to exist among transplant centers, with candidates listed at lower acceptance rate centers being more likely to experience mortality while on the waitlist. Comparable posttransplant survival suggests that allografts that were declined as a first offer perform as well as those that were accepted at their first offer. These findings suggest that organ acceptance rate or time to transplant from being added to the waitlist may be an additional measure of heart transplant program performance.

Causes of donation failure and improvement measures analyzed based on data from domestic deceased donors in 2019

In 2019, 1,630 organs were recovered from 450 brain death donors nationwide and were transplanted into 1,612 transplant recipients. However, considering that the number of potential brain-dead linked to the Korea Organ Donation Agency (KODA) information center was 2,484, only 18.1% of the linked brain-dead donated successfully. Of the 1,606 people who were available for family interviews, 67.0% refused to donate, so their cause analysis and countermeasures are needed. In particular, 203 reported cases died during the early period of donor evaluation, so we need a special concern on these cases. After consent, 67 cases failed to donate due to death or poor organ condition, and this raises the question of the possibility of shortening brain death management time. The average time interval from the first investigation to the completion of the second investigation (11.5 hours), until obtaining a flat electroencephalogram (5.3 hours) and conclusion of the brain death committee is 5.9 hours. Reducing unnecessary brain death management time is expected to improve the quality of organs and increase the number of organs to be recovered. Therefore, efforts to accurately identify and report potential brain death, and efforts to reduce the time spent in confirming brain death together with improving awareness of organ donation in people across the country are necessary to increase the number of deceased donors even in the current brain death management system. Implementation of donation after circulatory death for mortality case during the donor management is also urgent.

Evaluation of underidentification of potential organ donors in German hospitals

Background

Since 2010, the number of organ donations in Germany has decreased by one third, mostly due to undetected organ donors. It is unclear, how the undetected potential donor pool is distributed among the different German hospital categories (A = university hospital, B = hospitals with neurosurgery, C = hospitals without neurosurgery) and region types.

Methods

We performed a nationwide secondary data analysis of all German inpatient cases of the year 2016 (n = 20,063,689). All fatalities were regarded as potential organ donors, in which primary or secondary brain damage was encoded and organ donation was not excluded by a contraindication or a lack of ventilation therapy.

Results

In 2016, 28,087 potential organ donors were identified. Thereof 21% were found in category A, 28% in category B and 42% in category C hospitals. The contact rate (= organ donation related contacts/ potential organ donors) and realization rate (= realized organ donations/ potential organ donors) of category A, B and C hospitals was 10.6% and 4.6%, 10.9% and 4.8% and 6.0% and 1.7%, respectively. 58.2% of the donor potential of category C hospitals was found in the largest quartile of category C hospitals. 51% (n = 14,436) of the potential organ donors were treated in hospitals in agglomeration areas, 28% (n = 7,909) in urban areas and 21% (n = 5,742) in rural areas. The contact- and realization rate did not significantly differ between these areas.

Conclusions

The largest proportion of potential organ donors and the lowest realization rate are found in category C hospitals. Reporting and donation practice do not differ between urban and rural regions.

The Centers for Medicare and Medicaid Services' proposed metrics for recertification of organ procurement organizations: Evaluation by the Scientific Registry of Transplant Recipients

On December 23, 2019, the US Centers for Medicare and Medicaid Services proposed 2 new standards that organ procurement organizations (OPOs) must meet for recertification. An OPO's organ donation rate (deceased donors/potential donors) and organ transplant rate (organs transplanted/potential donors) must not fall significantly below the 75th percentile for rates among all OPOs. We examined how OPOs would have fared under the proposed performance standards in 2016-2017. Data on donors and transplants were from the Organ Procurement and Transplantation Network; donor potential was estimated from Detailed Multiple Cause of Death data collected by the Centers for Disease Control and Prevention. In 2017, 31 (53%) OPOs failed to meet the proposed donation rate standard, 36 (62%) failed to meet the proposed organ transplant rate standard, and 37 (64%) failed at least 1 standard. We found that adjusting for age, race, and Hispanic ethnicity altered the evaluation: 8 OPOs changed their pass/fail status for the donation rate and 5 for the proposed organ transplant rate standard. We conclude that the proposed new standards may result in over half of OPOs facing decertification, and risk adjustment suggests that underlying characteristics of deaths vary regionally such that decertification decisions may be affected.

Senolytics prevent mt-DNA-induced inflammation and promote the survival of aged organs following transplantation

Older organs represent an untapped potential to close the gap between demand and supply in organ transplantation but are associated with age-specific responses to injury and increased immunogenicity, thereby aggravating transplant outcomes. Here we show that cell-free mitochondrial DNA (cf-mt-DNA) released by senescent cells accumulates with aging and augments immunogenicity. Ischemia reperfusion injury induces a systemic increase of cf-mt-DNA that promotes dendritic cell-mediated, age-specific inflammatory responses. Comparable events are observed clinically, with the levels of cf-mt-DNA elevated in older deceased organ donors, and with the isolated cf-mt-DNA capable of activating human dendritic cells. In experimental models, treatment of old donor animals with senolytics clear senescent cells and diminish cf-mt-DNA release, thereby dampening age-specific immune responses and prolonging the survival of old cardiac allografts comparable to young donor organs. Collectively, we identify accumulating cf-mt-DNA as a key factor in inflamm-aging and present senolytics as a potential approach to improve transplant outcomes and availability.

Organ transplantation involving aged donors is often confounded by reduced post-transplantation organ survival. By studying both human organs and mouse transplantation models, here the authors show that pretreating the donors with senolytics to reduce mitochondria DNA and pro-inflammatory dendritic cells may help promote survival of aged organs.

Wide Variation in the Percentage of Donation After Circulatory Death Donors Across Donor Service Areas: A Potential Target for Improvement

BACKGROUND

Substantial differences exist in the clinical characteristics of donors across the 58 donor service areas (DSAs). Organ procurement organization (OPO) performance metrics incorporate organs donated after circulatory determination of death (DCDD) donors but do not measure potential DCDD donors.

METHODS

Using 2011-2016 United Network for Organ Sharing data, we examined the variability in DCDD donors/all deceased donors (%DCDD) across DSAs. We supplemented United Network for Organ Sharing data with CDC death records and OPO statistics to characterize underlying process and system factors that may correlate with donors and utilization.

RESULTS

Among 52 184 deceased donors, the %DCDD varied widely across DSAs, with a median of 15.1% (interquartile range [9.3%, 20.9%]; range 0.0%-32.0%). The %DCDD had a modest positive correlation with 4 DSA factors: median match model for end-stage liver disease, proportion of white deaths out of total deaths, kidney center competition, and %DCDD livers by a local transplant center (all Spearman coefficients 0.289-0.464), and negative correlation with 1 factor: mean kidney waiting time (Spearman coefficient -0.388). Adjusting for correlated variables in linear regression explained 46.3% of the variability in %DCDD.

CONCLUSIONS

Donor pool demographics, waitlist metrics, center competition, and DCDD utilization explain only a portion of the variability of DCDD donors. This requires further studies and policy changes to encourage consideration of all possible organ donors.

Addressing Critiques of the Proposed CMS Metric of Organ Procurement Organ Performance: More Data Isn't Better

BACKGROUND

Centers for Medicare and Medicaid Services (CMS) has proposed a rule change to redefine the metric by which organ procurement organizations (OPOs) are evaluated. The metric relies on Centers for Disease Control and Prevention (CDC) data on inpatient deaths from causes consistent with donation among patients <75 years of age. Concerns have been raised that this metric does not account for rates of ventilation, and prevalence of cancer and severe sepsis, without objective data to substantiate or refute such concerns.

METHODS

We estimated OPO-level donation rates using CDC data, and used Agency for Healthcare Research and Quality/Healthcare Cost and Utilization Project data from 43 State Inpatient Databases to calculate "adjusted" donation rates.

RESULTS

The CMS metric and the ventilation-adjusted CMS metric were highly concordant in absolute terms (Spearman and Pearson correlation coefficients ≥0.95). In the Bland-Altman plot, 100% (48/48) of paired values (standard deviations [SDs] of the CMS and "ventilation adjusted" metrics) were within 1.96 SDs of the mean difference, with near-perfect correlation in Passing and Bablok regression (Lin's concordance correlation coefficient: 0.97). The CMS metric and the ventilation/cancer/sepsis-adjusted metric were highly concordant in absolute terms (Spearman and Pearson correlation coefficients ≥0.94). In the Bland-Altman plot, 97.9% (47/48) of paired values (SDs of the CMS and "ventilation/cancer/sepsis adjusted" metrics) were within 1.96 SDs of the mean difference, with near-perfect correlation in the Passing and Bablok regression (Lin's concordance correlation coefficient: 0.97).

CONCLUSIONS

These conclusions should provide CMS, and the transplant community, with comfort that the proposed CMS metric using CDC inpatient death data as a tool to compare OPO is not compromised by its lack of inclusion of ventilation or other comorbidity data.

A Systematic Review of Opt-out Versus Opt-in Consent on Deceased Organ Donation and Transplantation (2006-2016)

BACKGROUND

Significant numbers of patients in the USA and UK die while waiting for solid organ transplant. Only 1-2% of deaths are eligible as donors with a fraction of the deceased donating organs. The form of consent to donation may affect the organs available. Forms of consent include: opt-in, mandated choice, opt-out, and organ conscription. Opt-in and opt-out are commonly practiced. A systematic review was conducted to determine the effect of opt-in versus opt-out consent on the deceased donation rate (DDR) and deceased transplantation rate (DTR).

METHODS

Literature searches of PubMed and EMBASE between 2006 and 2016 were performed. Research studies were selected based on certain inclusion criteria which include USA, UK, and Spain; compare opt-in versus opt-out; primary data analysis; and reported DDR or DTR. Modeled effect on US transplant activity was conducted using public data from Organ Procurement and Transplantation Network and Centers for Disease Control WONDER from 2006 to 2015.

RESULTS

A total of 2400 studies were screened and six studies were included. Four studies reported opt-out consent increases DDR by 21-76% over 5-14 years. These studies compared 13-25 opt-out countries versus 9-23 opt-in countries. Three studies reported opt-out consent increases DTR by 38-83% over 11-13 years. These studies compared 22-25 opt-out versus 22-28 opt-in countries. Modeled opt-out activity on the USA resulted in 4753-17,201 additional transplants annually.

CONCLUSION

Opt-out consent increases DDR and DTR and may be useful in decreasing deaths on the waiting list in the USA and other countries.

REGISTRATION NUMBER

PROSPERO CRD42019098759.

An international comparison of deceased donor kidney utilization: What can the United States and the United Kingdom learn from each other?

In transplant, meaningful international comparisons in organ utilization are needed. This collaborative study between the United Kingdom (UK) and the United States (US) aimed to develop a kidney utilization metric allowing for legitimate intercountry comparisons. Data from the UK and US transplant registries, including all deceased donor kidneys recovered from 2006 to 2017, were analyzed. To identify a potentially comparable kidney utilization rate (UR), several denominators were assessed. We discovered that the proportion of transplanted kidneys from elderly donors in the UK (10.7%) was 18 times greater than that in the US (0.6%). Conversely, en bloc pediatric kidney transplant was more common in the US. Donation after circulatory death utilization has risen in both countries but is twice as prevalent in the UK (39% of transplants) vs the US (20%). In addition, US and UK URs are not directly comparable due to fundamental system differences. However, using a suite of URs revealed practice areas likely to yield the most benefit if improved, such as efforts to increase kidney offer acceptance in the US and to reduce postacceptance discard in the UK. Methods used in this study, including novel intracountry risk-adjusted UR trend logistic regression analyses, can be translated to other international transplant registries in pursuit of further global learning opportunities.

How Inaccurate Metrics Hide the True Potential for Organ Donation in the United States

BACKGROUND

There is a discrepancy between the reported increase in donor conversion rates and the number of organs available for transplant.

METHODS

Secondary analysis of data obtained from the Scientific Registry of Transplant Recipients from January 2003 through December 2015 was performed. The primary outcomes were the (1) number of brain-dead donors from whom solid organs were recovered and (2) number of the organs transplanted. Descriptive statistics and growth plots were used to examine the trajectory of organ donation, recovery, and transplantation outcomes over the 11-year period.

RESULTS

From 2003 to 2006, the number of brain-dead donors increased from 6187 to 7375, remaining relatively stable at approximately 7200 thereafter. The average eligible deaths per organ procurement organization dropped from 182.7 (standard deviation [SD]: 131.3) in 2003 to 149.3 (SD: 111.4) in 2015. This suggests a total of 12 493 unrealized potential donors (2006-2015).

CONCLUSIONS

Since 2006, a steady decline in the number of donor-eligible deaths was reported. In 2003, the reported eligible deaths was 11 326. This number peaked in 2004 at 11 346, tumbling to 9781 eligible donors in 2015, despite a 9% increase in the US population. From 2006 to 2015, the data indicate an artificial depression and underestimation of the true potential of brain-dead donors in the United States of conservatively 12 493 donors or 39 728 missing organs. New metrics providing objective but verifiable counts of the donor pool are needed.

Decline in Organ Donation in Germany

BACKGROUND

The annual number of post-mortem organ donations in Germany has declined by more than 30% since 2010. The causes of this development have not yet been adequately determined.

METHODS

All patients hospitalized in Germany between 2010 and 2015 (112 172 869 hospitalizations in total) were included in this nationwide secondary analysis. Among the deceased patients we identified those who had died in the presence of a brain damage and for whom organ donation was not excluded either by a medical contraindication or by the patient's not having been artificially ventilated. The analysis was also conducted separately for six German university hospitals.

RESULTS

Over the period 2010-2015, the number of potential organ donors per year in Germany rose by 13.9%, from 23 937 to 27 258. This development was due to an increase in the number of deaths with severe brain damage as well as an increase in the percentage of patients who were treated with invasive ventilation before death. The contact quotient, i.e., the percentage of potential donors for whom contact was made with the German Foundation for Organ Transplantation (Deutsche Stiftung Organtransplantation, DSO) fell over this period from 11.4% to 8.2%. At the same time, the realization quotient (the percentage of potential donors who became actual donors) fell from 5.4% to 3.2%, and the conversion quotient (the percentage of potential donors for whom contact was made who became actual donors) fell from 47% to 39.1%. From 2010 to 2012, the falling realization quotient was accounted for mainly by the falling conversion quotient; from 2012 to 2015, it was accounted for mainly by the falling contact quotient. The contact and realization quotients among the six university hospitals studied differed markedly (by factors of 17.5 and 23.3, respectively), while the conversion quotients differed only minimally (by a factor of 1.3).

CONCLUSION

The decline in post-mortem organ donation is due to a deficiency in the recognition and reporting of potential organ donors in hospital. If this process were better supported on the organizational and political level, far more organs could be transplanted.

Geographic disparities in liver supply/demand ratio within fixed-distance and fixed-population circles

Recent OPTN proposals to address geographic disparity in liver allocation have involved circular boundaries: the policy selected 12/17 allocated to 150-mile circles in addition to DSAs/regions, and the policy selected 12/18 allocated to 150-mile circles eliminating DSA/region boundaries. However, methods to reduce geographic disparity remain controversial, within the OPTN and the transplant community. To inform ongoing discussions, we studied center-level supply/demand ratios using SRTR data (07/2013-06/2017) for 27 334 transplanted deceased donor livers and 44 652 incident waitlist candidates. Supply was the number of donors from an allocation unit (DSA or circle), allocated proportionally (by waitlist size) to the centers drawing on these donors. We measured geographic disparity as variance in log-transformed supply/demand ratio, comparing allocation based on DSAs, fixed-distance circles (150- or 400-mile radius), and fixed-population (12- or 50-million) circles. The recently proposed 150-mile radius circles (variance = 0.11, P = .9) or 12-million-population circles (variance = 0.08, P = .1) did not reduce the geographic disparity compared to DSA-based allocation (variance = 0.11). However, geographic disparity decreased substantially to 0.02 in both larger fixed-distance (400-mile, P < .001) and larger fixed-population (50-million, P < .001) circles (P = .9 comparing fixed distance and fixed population). For allocation circles to reduce geographic disparities, they must be larger than a 150-mile radius; additionally, fixed-population circles are not superior to fixed-distance circles.

Renal transplantation from seropositive hepatitis C virus donors to seronegative recipients in Spain: a prospective study

Hepatitis C virus (HCV) positive donors are identified in Spain by antibody detection (HCV-Ab) techniques while a HCV nuclear acid-testing (HCV-NAT) is not mandatory. Since it has been shown that HCV-Ab positive HCV-NAT negative donors do not universally transmit the infection, we designed a protocol based on the identification of viremia in HCV-Ab positive donors to start treatment if needed. HCV-Ab-positive donors were identified and we performed HCV-NAT immediately. Donors coinfected with HIV were excluded. Recipients with a low chance to receive a transplant, with no history of liver disease and who were negative for HCV-Ab were selected after informed consent was signed. Kidney recipients from HCV-NAT-positive donors received glecaprevir and pibrentasvir from 6 h before the transplant until 8 weeks after. Recipients from HCV-NAT-negative donors were not treated. Regular monitoring by HCV-NAT was performed to initiate antiviral treatment. We included 11 recipients from six deceased donors Four recipients received grafts from HCV-NAT-positive donors and seven patients received grafts from HCV-NAT-negative donors. None of our recipients exhibited HCV-NAT positivity during the minimum follow-up period of 6 months. Recipients from HCV-NAT-positive donors exhibited sustained virologic response at 12 weeks. One recipient from an HCV-NAT-negative donor lost his graft via a process thought to be unrelated to HCV. The remaining 10 patients had a stable functioning graft at the end of the follow-up period. Our preliminary data suggest that renal transplantation from HCV-Ab- positive donors to HCV-Ab negative recipients is safe when only the recipients of organs from HCV-NAT-positive donors are treated.