Expanding Liver Transplant Opportunities in Older Patients With Nonconventional Grafts.

INTRODUCTION: Broader use of donation after circulatory death (DCD) and nonconventional grafts for liver transplant helps reduce disparities in organ availability. Limited data, however, exists on outcomes specific to nonconventional graft utilization in older patients. As such, this study aimed to investigate outcomes specific to conventional and nonconventional graft utilization in recipients > 70 y of age. METHODS: 1-to-3 matching based on recipient sex, Model for End-Stage Liver Disease score, and donor type was performed on patients ≥70 and <70 y of age who underwent liver transplant alone at Mayo Clinic Arizona between 2015 and 2020. Primary outcomes were posttransplant patient and liver allograft survival for recipients greater than or less than 70 y of age. Secondary outcomes included grafts utilization patterns, hospital length of stay, need for reoperation, biliary complications and disposition at time of hospital discharge. RESULTS: In this cohort, 36.1% of grafts came from DCD donors, 17.4% were postcross clamp offers, and 20.8% were nationally allocated. Median recipient ages were 59 and 71 y (P < 0.01). Recipients had similar Intensive care unit (P = 0.82) and hospital (P = 0.14) lengths of stay, and there were no differences in patient (P = 0.68) or graft (P = 0.38) survival. When comparing donation after brain death and DCD grafts in those >70 y, there were no differences in patient (P = 0.89) or graft (P = 0.71) survival. CONCLUSIONS: Excellent outcomes can be achieved in older recipients, even with use of nonconventional grafts. Expanded use of nonconventional grafts can help facilitate transplant opportunities in older patients.

Retransplanting a previously transplanted kidney: A safe strategy in times of organ shortage?

BACKGROUND: The shortage of organs for transplantation remains a global problem. The retransplantation of a previously transplanted kidney might be a possibility to expand the pool of donors. We provide our experience with the successful reuse of transplanted kidneys in the Eurotransplant region. METHODS: A query in the Eurotransplant database was performed between January 1, 1995 and December 31, 2015, to find kidney donors who themselves had previously received a kidney graft. RESULTS: Nine out of a total of 68,554 allocated kidneys had previously been transplanted. Four of these kidneys were transplanted once again. The mean interval between the first transplant and retransplantation was 1689±1682 days (SD; range 55-5,333 days). At the time of the first transplantation the mean serum creatinine of the donors was 1.0 mg/dl (.6-1.3 mg/dl) and at the second transplantation 1.4 mg/dl (.8-1.5 mg/dl). The mean graft survival in the first recipient was 50 months (2-110 months) and in the second recipient 111 months (40-215 months). CONCLUSION: Transplantation of a previously transplanted kidney may successfully be performed with well-preserved graft function and long-term graft survival, even if the first transplantation was performed a long time ago. Such organs should be considered even for younger recipients in carefully selected cases.

Outcomes of dual kidney transplants from high KDPI kidneys are superior compared to single kidney high KDPI transplants at 1 year.

Dual kidney transplantation (DKT), utilizing two adult kidneys from the same donor for one recipient, has been used as a way to expand the available donor pool. These kidneys often come from high Kidney Donor Profile Index donors (KDPI > 85%). Data comparing outcomes between high KDPI DKT and single kidney transplants (SKT) remain limited. We assessed outcomes of 336 high KDPI kidney transplants performed at our center; 11.0% (n = 37) were DKT. Recipients of DKT were older (P = .02) and donors had a higher KDPI score (median 96% vs. 91%, P < .0001). DKT operative time was higher compared to SKT (+1.4 hours, P < .0001). There were no differences in delayed graft function (54.1% vs. 51.5%, P = .77) and hospital length of stay (median 4.0 vs. 3.0 days, P = .21) between DKT and SKT. Grade I Clavien-Dindo complications occurred in 8.1% of DKT and 13.7% of SKT (P = .008). There were no grade IVa, IVb, or V complications in either group. DKT had more glomerulosclerosis (P = .04), interstitial fibrosis (P = .02), tubular atrophy (P = .01), and arterial thickening (P = .03) on 1-year protocol biopsies. Estimated glomerular filtration was higher for DKT at 1- (P = .004) and 2-years post-transplant (P = .01). There were no differences in patient (HR 1.3, 95% CI .5-3.3, P = .58) or graft (HR 1.1, 95% CI .5-2.3, P = .83) survival. Good outcomes can be achieved with DKT using high KDPI kidneys with moderate chronic changes. DKT is a good option to help further utilize high KDPI kidneys and minimize discard.

Ethical Solutions to the Problem of Organ Shortage.

Organ shortage is a major survival issue for millions of people worldwide. Globally 1.2 million people die each year from kidney failure. In this paper, we critically examine and find lacking extant proposals for increasing organ supply, such as opting in and opt out for deceased donor organs, and parochial altruism and paired kidney exchange for live organs. We defend two ethical solutions to the problem of organ shortage. One is to make deceased donor organs automatically available for transplant without requiring consent from the donor or their relatives. The other is for society to buy nonvital organs in a strictly regulated market and provide them to people in need for free.

Decreasing Significance of Early Allograft Dysfunction with Rising Use of Nonconventional Donors.

Background and Objectives: Early allograft dysfunction (EAD) is considered a surrogate marker for adverse post-liver transplant (LT) outcomes. With the increasing use of nonconventional donors, EAD has become a more frequent occurrence. Given this background, we aimed to assess the prevalence and impact of EAD in an updated cohort inclusive of both conventional and nonconventional liver allografts. Materials and Methods: Perioperative and one-year outcomes were assessed for a total of 611 LT recipients with and without EAD from Mayo Clinic Arizona. EAD was defined as the presence of one or more of the following: bilirubin > 10 mg/dL on day 7, INR > 1.6 on day 7, or ALT and/or AST > 2000 IU/L within the first 7 days of LT. Results: Within this cohort, 31.8% of grafts (n = 194) came from donation after circulatory death (DCD) donors, 17.7% (n = 108) were nationally shared, 16.4% (n = 100) were allocated as post-cross clamp, and 8.7% contained moderate steatosis. EAD was observed in 52.2% (n = 321) of grafts in the study cohort (79% in DCD grafts and 40% in DBD grafts). EAD grafts had higher donor risk index (DRI) scores (1.9 vs. 1.6, p < 0.0001), were more likely to come from DCD donors (48% vs. 13.8%, p < 0.0001), were regionally allocated (p = 0.003), and had higher cold ischemia times (median 6.0 vs. 5.5 h, p = 0.001). Primary nonfunction events were rare in both groups (1.3% vs. 0.3%, p = 0.22). Post-LT acute kidney injury occurred at a similar frequency in recipients with and without EAD (43.6% vs. 30.3%, p = 0.41), and there were no differences in ICU (median 2 vs. 1 day, p = 0.60) or hospital (6 vs. 5 days, p = 0.24) length of stay. For DCD grafts, the rate of ischemic cholangiopathy was similar in the two groups (14.9% EAD vs. 17.5% no EAD, p = 0.69). One-year patient survival for grafts with and without EAD was 96.0% and 94.1% (HR 1.2, 95% CI 0.7−1.8; p = 0.54); one-year graft survival was 92.5% and 92.1% (HR 1.0, 95% CI 0.7−1.5; p = 0.88). Conclusions: In this cohort, EAD occurred in 52% of grafts. The occurrence of EAD, however, did not portend inferior outcomes. Compared to those without EAD, recipients with EAD had similar post-operative outcomes, as well as one-year patient and graft survival. EAD should be managed supportively and should not be viewed as a deterrent to utilization of non-ideal grafts.

Why are there so many liver transplants from living donors in Asia and so few in Europe and the US?

Acceptance of liver transplantation (LT) as an established treatment modality for end-stage liver disease has led to an exponential increase in the demand for organs, resulting in an ever-increasing gap between the availability of organs and the number of sick patients waiting for them. Interestingly, influenced by cultural, socio-economic and other constraints, the West and the East have attempted to address this problem of shortage in different ways. Living donor LT (LDLT) became polarised to the East with over 90% of LT in this region being LDLT. On the other hand, the West chose to concentrate their efforts on optimising the use of cadaveric livers with techniques such as split LT, or by using extended criteria donors (including donation after cardiac death donors) and machine perfusion devices etc. Consequently, LDLT did not find the widespread acceptance it did in the East and hence over 90% of all LT are DDLT in this region. We review each regions' perspective and attempt to provide a globally viable roadmap to bridge the widening gap between the demand and availability of livers for LT.

Successful Reuse of Kidney Graft After Early Recurrence of Primary Focal and Segmental Glomerulosclerosis.

Primary focal and segmental glomerulosclerosis (FSGS) frequently recurs after transplantation and is associated with a poor prognosis. We describe here the successful kidney graft reuse in an adult recipient, 8 months after early primary FSGS recurrence resistant to all available therapeutics. Patient 1, a 23-year-old man, followed for kidney failure secondary to primary FSGS, was first transplanted in 2018 with a deceased donor graft. Unfortunately, we observed an immediate recurrence of biopsy-proven primary FSGS. After 4 lines of treatment (intravenous cyclosporine+corticosteroids, plasma exchanges, immunoadsorption, and rituximab), the patient was still highly nephrotic and kidney function was slowly deteriorating. After approval from both the patient and the health authority (Biomedicine Agency), the graft was detransplanted 8 months after transplantation and reimplanted in patient 2, a 78-year-old nonimmunized and anephric recipient (bi-nephrectomy 2 years previously for bilateral renal carcinoma). We observed immediate kidney function and progressive resolution of proteinuria (serum creatinine of 1.2mg/dL and proteinuria of 0.1 g/d 1 year later). Biopsies performed after surgery showed persistent FSGS lesions with a decrease in overall foot-process effacement. To our knowledge, this is the first reported case showing that kidney graft transfer may still be a viable option for refractory primary FSGS several months after transplantation.

Organ transplants of the future: planning for innovations including xenotransplantation.

The future clinical application of animal-to-human transplantation (xenotransplantation) is of importance to society as a whole. Favourable preclinical data relevant to cell, tissue and solid organ xenotransplants have been obtained from many animal models utilizing genetic engineering and protocols of pathogen-free husbandry. Findings have reached a tipping point, and xenotransplantation of solid organs is approaching clinical evaluation, the process of which now requires close deliberation. Such discussions include considering when there is sufficient evidence from preclinical animal studies to start first-in-human xenotransplantation trials. The present article is based on evidence and opinions formulated by members of the European Society for Organ Transplantation who are involved in the Transplantation Learning Journey project. The article includes a brief overview of preclinical concepts and biology of solid organ xenotransplantation, discusses the selection of candidates for first-in-human studies and considers requirements for study design and conduct. In addition, the paper emphasizes the need for a regulatory framework for xenotransplantation of solid organs and the essential requirement for input from public and patient stakeholders.

The Most Good You Can Do with Your Kidneys: Effective Altruism and the Organ-Shortage Problem.

Effective altruism is a growing philosophical and social movement, whose members design their lives in ways aligned with doing the most good that they can do. The main focus of this paper is to explore what effective altruism has to say about the moral obligations people have to do good with their organs, in the face of an organ-shortage problem. It is argued that an effective altruism framework offers a number of valuable theoretical and practical insights relevant to ongoing debate about how to resolve the organ-shortage problem. Its recommendations constitute a plausible and promising strategy for increasing the supply of, and decreasing the demand for, human organs, in a way that protects (rather than ignores, or preys upon) the global poor. And, many of its recommendations can be implemented into policy without requiring that citizens actually become effective altruists themselves.

Viability testing of discarded livers with normothermic machine perfusion: Alleviating the organ shortage outweighs the cost.

BACKGROUND: Over 700 donor livers are discarded annually in the United States due to high risk of poor graft function. The objective of this study was to determine the impact of using normothermic machine perfusion to identify transplantable livers among those currently discarded. STUDY DESIGN: A series of 21 discarded human livers underwent viability assessment during normothermic machine perfusion. Cross-sectional analysis of the Scientific Registry of Transplant Recipients database and cost analysis was performed to extrapolate the case series to national experience. RESULTS: 21 discarded human livers were included in the perfusion cohort. 11 of 20 (55%) eligible grafts met viability criteria for transplantation. Grafts in the perfusion cohort had a similar donor risk index compared with discarded grafts (n = 1402) outside of New England in 2017 and 2018 (median [IQR]: 2.0 [1.5, 2.4] vs. 2.0 [1.7, 2.3], P = .40). 705 (IQR 677-741) livers were discarded annually in the United States since 2005, translating to the potential for 398 additional transplants nationally. The median cost to identify a transplantable graft with machine perfusion was $28,099 USD. CONCLUSIONS: Normothermic machine perfusion of discarded livers could identify a significant number of transplantable grafts, significantly improving access to liver transplantation.

Promising potentials of Tibetan macaques in xenotransplantation.

Organ transplantation is a crucial medical procedure, as it is often the only treatment for patients suffering from end-stage organ failure. Unfortunately, the shortage of donor organs limits the number of patients whose lives can be saved. Carrying out research on xenotransplantation with the aim of eventually replacing human organ transplants with those of animals is very promising, as it could effectively bridge the shortfall in donor organs. Thanks to the success of cloned pigs and to the emergence of gene-editing techniques, genetically modified pigs have come to be considered ideal animal donors for human xenotransplantation and have been widely used in basic research. Such research focuses on pig-to-nonhuman primates transplantation, as the recipients are suitable for preclinical studies because both their genes and organ sizes are similar to those of humans. Chinese transplantation scientists have carried out several experiments on Tibetan macaques, including successful preclinical transplants of material from genetically modified pigs, as well as research on such topics as intraocular pressure, Parkinson's disease, advanced cancer, islet transplantation, and liver transplantation. This article reviews basic and applied research on Tibetan macaques in xenotransplantation, as well as the issues of immune rejection and ethical concerns. We aim to demonstrate the various advantages of Tibetan macaques as transplant recipients compared to other nonhuman primate species and to provide a perspective for the future establishment of Tibetan macaques as principal recipients in preclinical studies of xenotransplantation.

Strategies based on organ decellularization and recellularization.

Transplantation is the only curative treatment option available for patients suffering from end-stage organ failure, improving their quality of life and long-term survival. However, because of organ scarcity, only a small number of these patients actually benefit from transplantation. Alternative treatment options are needed to address this problem. The technique of whole-organ decellularization and recellularization has attracted increasing attention in the last decade. Decellularization includes the removal of all cellular components from an organ, while simultaneously preserving the micro and macro anatomy of the extracellular matrix. These bioscaffolds are subsequently repopulated with patient-derived cells, thus constructing a personalized neo-organ and ideally eliminating the need for immunosuppression. However, crucial problems have not yet been satisfyingly addressed and remain to be resolved, such as organ and cell sources. In this review, we focus on the actual state of organ de- and recellularization, as well as the problems and future challenges.

Potentially inappropriate liver transplantation in the era of the "sickest first" policy - A search for the upper limits.

Liver transplantation has emerged as a highly efficient treatment for a variety of acute and chronic liver diseases. However, organ shortage is becoming an increasing problem globally, limiting the applicability of liver transplantation. In addition, potential recipients are becoming sicker, thereby increasing the risk of losing the graft during transplantation or in the initial postoperative period after liver transplantation (three months). This trend is challenging the model for end-stage liver disease allocation system, where the sickest candidates are prioritised and no delisting criteria are given. The weighting of the deontological demand for "equity", trying to save every patient, regardless of the overall utility; and "efficiency", rooted in utilitarianism, trying to save as many patients as possible and increase the overall quality of life of patients facing the same problem, has to be reconsidered. In this article we are aiming to overcome the widespread concept of futility in liver transplantation, providing a definition of potentially inappropriate liver transplantation and giving guidance on situations where it is best not to proceed with liver transplantation, to decrease the mortality rate in the first three months after transplantation. We propose "absolute" and "relative" conditions, where early post-transplant mortality is highly probable, which are not usually captured in risk scores predicting post-transplant survival. Withholding liver transplantation for listed patients in cases where liver transplant is not deemed clearly futile, but is potentially inappropriate, is a far-reaching decision. Until now, this decision had to be discussed extensively on an individual basis, applying explicit communication and conflict resolution processes, since the model for end-stage liver disease score and most international allocation systems do not include explicit delisting criteria to support a fair delisting process. More work is needed to better identify cases where transplantation is potentially inappropriate and to integrate and discuss these delisting criteria in allocation systems, following a societal debate on what we owe to all liver transplant candidates.

Generating Human Organs via Interspecies Chimera Formation: Advances and Barriers.

The shortage of human organs for transplantation is a devastating medical problem. One way to expand organ supply is to derive functional organs from patient-specific stem cells. Due to their capacity to grow indefinitely in the laboratory and differentiate into any cell type of the human body, patient-specific pluripotent stem (PS) cells harbor the potential to provide an inexhaustible supply of donor cells for transplantation. However, current efforts to generate functional organs from PS cells have so far been unsuccessful. An alternative and promising strategy is to generate human organs inside large animal species through a technique called interspecies blastocyst complementation. In this method, animals comprised of cells from human and animal species are generated by injecting donor human PS cells into animal host embryos. Critical genes for organ development are knocked out by genome editing, allowing donor human PS cells to populate the vacated niche. In principle, this experimental approach will produce a desired organ of human origin inside a host animal. In this mini-review, we focus on recent advances that may bring the promise of blastocyst complementation to clinical practice. While CRISPR/Cas9 has accelerated the creation of transgenic large animals such as pigs and sheep, we propose that further advances in the generation of chimera-competent human PS cells are needed to achieve interspecies blastocyst complementation. It will also be necessary to define the constituents of the species barrier, which inhibits efficient colonization of host animal embryos with human cells. Interspecies blastocyst complementation is a promising approach to help overcome the organ shortage facing the practice of clinical medicine today.

Expanding access to transplantation with hepatitis C-positive donors: A new perspective on an old issue.

With the need for organs far exceeding supply, donors previously exposed to hepatitis B (HBV) and hepatitis C (HCV) viral infections should be considered for transplantation. Although many centers have protocols for transplanting organs from HBV core antibody-positive (HBcAb+) donors into select recipients, in the era of direct-acting antivirals (DAAs), a new focus should be placed on HCV-positive donors. The transmission rate from HCV antibody-positive (HCVAb+) nucleic acid testing negative (HCV NAT-) donors is expected to be very low, and we encourage use of such organs in HCV recipients provided a normal biopsy, appropriate counseling, and careful post-transplant monitoring. While transmission of HCV from HCV NAT+ donors is universal, the success of DAA in obtaining a sustained viral response in post-transplant recipients should make the use of these organs more appealing. We herein provide information to help guide the use of organs from HCV donors.

The production of multi-transgenic pigs: update and perspectives for xenotransplantation.

The domestic pig shares many genetic, anatomical and physiological similarities to humans and is thus considered to be a suitable organ donor for xenotransplantation. However, prior to clinical application of porcine xenografts, three major hurdles have to be overcome: (1) various immunological rejection responses, (2) physiological incompatibilities between the porcine organ and the human recipient and (3) the risk of transmitting zoonotic pathogens from pig to humans. With the introduction of genetically engineered pigs expressing high levels of human complement regulatory proteins or lacking expression of α-Gal epitopes, the HAR can be consistently overcome. However, none of the transgenic porcine organs available to date was fully protected against the binding of anti-non-Gal xenoreactive natural antibodies. The present view is that long-term survival of xenografts after transplantation into primates requires additional modifications of the porcine genome and a specifically tailored immunosuppression regimen compliant with current clinical standards. This requires the production and characterization of multi-transgenic pigs to control HAR, AVR and DXR. The recent emergence of new sophisticated molecular tools such as Zinc-Finger nucleases, Transcription-activator like endonucleases, and the CRISPR/Cas9 system has significantly increased efficiency and precision of the production of genetically modified pigs for xenotransplantation. Several candidate genes, incl. hTM, hHO-1, hA20, CTLA4Ig, have been explored in their ability to improve long-term survival of porcine xenografts after transplantation into non-human primates. This review provides an update on the current status in the production of multi-transgenic pigs for xenotransplantation which could bring porcine xenografts closer to clinical application.

Drinking in the last chance saloon: luck egalitarianism, alcohol consumption, and the organ transplant waiting list.

The scarcity of livers available for transplants forces tough choices upon us. Lives for those not receiving a transplant are likely to be short. One large group of potential recipients needs a new liver because of alcohol consumption, while others suffer for reasons unrelated to their own behaviour. Should the former group receive lower priority when scarce livers are allocated? This discussion connects with one of the most pertinent issues in contemporary political philosophy; the role of personal responsibility in distributive justice. One prominent theory of distributive justice, luck egalitarianism, assesses distributions as just if, and only if, people's relative positions reflect their exercises of responsibility. There is a principled luck egalitarian case for giving lower priority to those who are responsible for their need. Compared to the existing literature favouring such differentiation, luck egalitarianism provides a clearer rationale of fairness, acknowledges the need for individual assessments of responsibility, and requires initiatives both inside and outside of the allocation systems aimed at mitigating the influence from social circumstances. Furthermore, the concrete policies that luck egalitarians can recommend are neither too harsh on those who make imprudent choices nor excessively intrusive towards those whose exercises of responsibility are assessed.

Changing the paradigm of organ utilization from PHS increased-risk donors: an opportunity whose time has come?

Approximately 8-11% of all organ donors are classified by Public Health Service (PHS) as increased-risk. The proportion of PHS increased-risk donors is on the rise. At the University of Washington Medical Center, in 2014, the proportion of transplants from PHS increased-risk donors was 28% of liver transplants and 23% of kidney transplants. Nationally, transplant providers have been reluctant to use organs from PHS increased-risk donors because of concern for transmission of HIV, HCV, or HBV. There is also patient apprehension when these organs are being offered, and thus the discard rate of these otherwise good quality organs is high. Because of the organ shortage, preventing underutilization of such organs is essential. We provide data and considerations that should be used to guide the use of organs from PHS increased-risk donors.

Perspectives of transplant physicians and surgeons on reimbursement, compensation, and incentives for living kidney donors.

BACKGROUND: The shortage of donors for organ transplantation has stimulated debate on financial incentives for living kidney donors. This study aims to describe the range of attitudes and opinions of transplant physicians on financial reimbursement, compensation, and incentives in living kidney donation. STUDY DESIGN: Qualitative study. SETTING & PARTICIPANTS: 110 transplant nephrologists and surgeons from 12 countries across 43 transplantation units in Europe, Australasia, and North America. METHODOLOGY: Face-to-face semistructured interviews were conducted. ANALYTICAL APPROACH: Transcripts were thematically analyzed. RESULTS: We identified 7 major themes. Prioritizing the removal of disincentives for living kidney donors was largely deemed acceptable. By contrast, provision of financial incentives raised concerns about undermining benevolence, compromising human dignity and value, and traversing market forces. Some contended that financial incentives potentially were legitimate if regulated, arguing that this would maximize utility in transplantation, but most also acknowledged the difficulty and that operational feasibility of a regulated system of financial incentivization may be limited. LIMITATIONS: Participants were English speaking and from Western high-income countries; therefore, the transferability of our findings may be limited. CONCLUSIONS: Transplantation specialists believed that minimizing disincentives would support equity and justice in living kidney donation. Direct financial incentivization for living kidney donors, even in the context of a regulated market, was regarded by most as unjustified because of the potential moral consequences and uncertain feasibility. Removing financial disincentives and safeguarding the intrinsic volunteerism, value, and meaning of donation were viewed to uphold integrity in living kidney donation.