Development and prospect of clinical research on lung transplantation in post-COVID-19 era

Lung transplantation has been advanced for nearly half a century around the globe, and it has been developed rapidly for over 20 years in China. The field of lung transplantation in China has been gradually integrated into the international community. The outbreak of novel coronavirus pneumonia (COVID-19) in 2020 brought big challenges, as well as diverted the worldwide attention to the development of lung transplantation in China, accelerating international communication and cooperation. With the steadily deepening of clinical and basic research on lung transplantation for severe cases of COVID-19, organ transplant physicians have deepened the understanding and thinking of the maintenance of donors, selection of elderly and pediatric candidates, and perioperative management of recipients, as the future perspective of lung transplantation in China. For interdisciplinary research related to lung transplantation, it is necessary to carry out multi-center clinical trials with qualified study design and constantly promote the theoretic and practical innovation.Copyright © 2021 The authors.

OPTN/SRTR 2021 Annual Data Report: Lung.

The number of lung transplants has continued to decline since 2020, a period that coincides with the onset of the COVID-19 pandemic. Lung allocation policy continues to undergo considerable change in preparation for adoption of the Composite Allocation Score system in 2023, beginning with multiple adaptations to the calculation of the Lung Allocation Score that occurred in 2021. The number of candidates added to the waiting list increased after a decline in 2020, while waitlist mortality has increased slightly with a decreased number of transplants. Time to transplant continues to improve, with 38.0% of candidates waiting fewer than 90 days for a transplant. Posttransplant survival remains stable, with 85.3% of transplant recipients surviving to 1 year; 67%, to 3 years; and 54.3%, to 5 years.

COVID-19 infection and vaccination rarely impact HLA antibody profile in waitlisted renal transplant candidates- a multicenter cohort.

Although rare, infection and vaccination can result in antibodies to human leukocyte antigens (HLA). We analyzed the effect of SARS-CoV-2 infection or vaccination on HLA antibodies in waitlisted renal transplant candidates. Specificities were collected and adjudicated if the calculated panel reactive antibodies (cPRA) changed after exposure. Of 409 patients, 285 (69.7 %) had an initial cPRA of 0 %, and 56 (13.7 %) had an initial cPRA > 80 %. The cPRA changed in 26 patients (6.4 %), 16 (3.9 %) increased, and 10 (2.4 %) decreased. Based on cPRA adjudication, cPRA differences generally resulted from a small number of specificities with subtle fluctuations around the borderline of the participating centers' cutoff for unacceptable antigen listing. All five COVID recovered patients with an increased cPRA were female (p = 0.02). In summary, exposure to this virus or vaccine does not increase HLA antibody specificities and their MFI in approximately 99 % of cases and 97 % of sensitized patients. These results have implications for virtual crossmatching at the time of organ offer after SARS-CoV-2 infection or vaccination, and these events of unclear clinical significance should not influence vaccination programs.

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

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

Expert consensus on organ donation from patients infected with novel coronavirus in China

The spread, prevention and control of novel coronavirus infection and the potential risks and uncertainties of novel coronavirus transmission from donor to recipient have brought serious impacts and great challenges to organ donation and transplantation. There is increasing evidence that the use of non-pulmonary organs (kidney, liver and heart) from novel coronavirus infected donors carries a low risk of transmission, regardless of whether they were symptomatic at the time of acquisition. Delaying organ donation after the death of those who are positive for novel coronavirus antigen or nucleic acid testing, and then waiting until turns negative, will result in the discarding of a significant number of organs that are medically suitable for transplantation. In order to maximally meet the demand for transplantation in patients with end-stage organ failure, Branch of Organ Transplantation of Chinese Medical Association organized relevant experts formulated the "Expert consensus on organ donation from patients infected with novel coronavirus in China” after citizen' s death by taking into account the epidemic situation of novel coronavirus infection in China and the clinical practice of organ donation and transplantation, and by referring to relevant research results and clinical research evidence at home and abroad. It aims to provide recommendations and references for the procurement and application of donor organs from patients infected with novel coronavirus. (English) [ FROM AUTHOR]

Caregiver COVID-19 vaccination for solid organ transplant candidates.

An increasing proportion of transplant centers have implemented a mandate for vaccination against COVID-19 for solid organ transplant candidates. There has been comparatively little exploration of the ethical considerations of mandating vaccination of a candidate's primary caregiver, despite a high risk of transmission given the close nature of contact between the candidate and caregiver. We examine how a caregiver mandate can improve overall utility in organ allocation, particularly in circumstances where vaccine effectiveness at preventing transmission and serious disease is low among recipients but high in caregivers. Our analysis reveals how sensitive such mandates must be to the evolving circumstances of disease severity, transmissibility, and vaccine effectiveness: as the facts change, the degree of benefit gained and therefore the degree of infringement on access to transplant and caregiver choice that is tolerated will likewise change.

OPTN/SRTR 2020 Annual Data Report: Lung.

For the first time in a decade, both the number of candidates added to the waiting list and the number of lung transplants performed decreased from the year prior; the number of lung donors also declined. This slowing of transplant activities in 2020 was associated with a modest increase in waitlist mortality. The year 2020 was notable for the global outbreak of the COVID-19 pandemic, which undoubtedly influenced all trends noted in lung transplantation. Time to transplant continued to decrease, with a median time to transplant of 1.4 months across all waitlist candidates. Posttransplant survival remained stable, with 89.4% of transplant recipients surviving to 1 year, 74.8% to 3 years, and 61.2% to 5 years.

A coordinated national UK liver transplant program response, prioritizing waitlist recipients with the highest need, provided excellent outcomes during the first wave of the COVID-19 pandemic.

INTRODUCTION: Healthcare provision has been severely affected by COVID-19, with specific challenges in organ transplantation. Here, we describe the coordinated response to, and outcomes during the first wave, across all UK liver transplant (LT) centers. METHODS: Several policy changes affecting the liver transplant processes were agreed upon. These included donor age restrictions and changes to offering. A "high-urgency" (HU) category was established, prioritizing only those with UKELD > 60, HCC reaching transplant criteria, and others likely to die within 90 days. Outcomes were compared with the same period in 2018 and 2019. RESULTS: The retrieval rate for deceased donor livers (71% vs. 54%; P < .0001) and conversion from offer to completed transplant (63% vs. 48%; P < .0001) was significantly higher. Pediatric LT activity was maintained; there was a significant reduction in adult (42%) and total (36%) LT. Almost all adult LT were super-urgent (n = 15) or HU (n = 133). We successfully prioritized those with highest illness severity with no reduction in 90-day patient (P = .89) or graft survival (P = .98). There was a small (5% compared with 3%; P = .0015) increase in deaths or removals from the waitlist, mainly amongst HU cohort. CONCLUSIONS: We successfully prioritized LT recipients in highest need, maintaining excellent outcomes, and waitlist mortality was only marginally increased.

The Heterogenous Effect of COVID-19 on Liver Transplantation Activity and Waitlist Mortality in the United States.

Background: The COVID-19 pandemic curtailed the practice of liver transplantation (LT), which lacks a temporizing life-saving measure for candidates on the waitlist. Aims/Objectives: The objective of this research was to (1) determine the effect of decreased LT activity on waitlist mortality in the United States and (2) assess if this effect was homogenous across the country. Methods: We conducted a retrospective, cross-sectional analysis utilizing United Network for Organ Sharing (UNOS) data assessing 3,600 liver transplants from January 1, 2020 to June 2, 2020. COVID-19 incidence data was taken directly from the New York Times case count. Results: During weeks 10 to 15 of 2020, there was a 38% reduction in the number of LTs performed nationally, which was temporally associated with a transient 97% increase in waitlist mortality. When stratified by UNOS region, waitlist mortality was inversely correlated with the number of LTs performed in all 11 regions. However, the range of the association strength (r) was large (Pearson correlation coefficient range: -0.73 to -0.01). Conclusion: Interruptions in LT activity due to COVID-19 were associated with rapid increases in waitlist mortality, and these effects were unevenly distributed among candidates across the United States. The transplant community can utilize these results to mitigate inequalities in transplant allocation between UNOS regions and advocate for the uninterrupted practice of LT should another pandemic surge or COVID-19 variant arise.

COVID-19 does not impact HLA antibody profile in a series of waitlisted renal transplant candidates.

HLA antibodies are typically produced after exposure to transplanted tissue, pregnancy, and blood products. Sensitization delays access to transplantation and preclude utilization of donor organs. Infections and vaccinations have also been reported to result in HLA antibody formation. It is not known if patients develop HLA antibodies after infection with SARS-CoV-2. Here we analyzed a series of eighteen patients waiting for kidney transplantation who had symptomatic COVID-19 disease and recovered. None of the patients in this initial series developed de novo HLA antibodies. Notably, there was no increase in preexisting HLA antibodies in four highly sensitized patients with a CPRA > 80%. These preliminary data suggest that there may not be a need to repeat HLA antibody testing or perform a physical crossmatch on admission serum before kidney transplant for COVID-19 recovered patients. Data from a large number of patients with different demographics needed.

Liver Transplantation for T2 Hepatocellular Carcinoma during the COVID-19 Pandemic: A Novel Model Balancing Individual Benefit against Healthcare Resources.

The COVID-19 pandemic caused temporary drops in the supply of organs for transplantation, leading to renewed debate about whether T2 hepatocellular carcinoma (HCC) patients should receive priority during these times. The aim of this study was to provide a quantitative model to aid decision-making in liver transplantation for T2 HCC. We proposed a novel ethical framework where the individual transplant benefit for a T2 HCC patient should outweigh the harm to others on the waiting list, determining a "net benefit", to define appropriate organ allocation. This ethical framework was then translated into a quantitative Markov model including Italian averages for waiting list characteristics, donor resources, mortality, and transplant rates obtained from a national prospective database (n = 8567 patients). The net benefit of transplantation in a T2 HCC patient in a usual situation varied from 0 life months with a model for end-stage liver disease (MELD) score of 15, to 34 life months with a MELD score of 40, while it progressively decreased with acute organ shortage during a pandemic (i.e., with a 50% decrease in organs, the net benefit varied from 0 life months with MELD 30, to 12 life months with MELD 40). Our study supports the continuation of transplantation for T2 HCC patients during crises such as COVID-19; however, the focus needs to be on those T2 HCC patients with the highest net survival benefit.

The Impact and Implications of The COVID-19 Pandemic on Organ Procurement Outside of an Epicenter.

The COVID-19 pandemic has been well-documented to have a variable impact on individual communities and health care systems. We describe the experience of a single organ procurement organization (OPO), located in an area without a large cluster of cases during the initial phase of the COVID-19 pandemic. A review of community health data describing the impact of COVID-19 nationally and in Oklahoma was conducted. Additionally, a retrospective review of available OPO data from March 2019-May 2020 was performed. While the amount of donor referrals received and organs recovered by the OPO remained stable in the initial months of the pandemic, the observed organs transplanted vs. expected organs transplanted (O:E) decreased to the lowest number in the 15-month period and organs transplanted decreased as well. Fewer organs from Oklahoma donors were accepted for transplant despite staff spending more time allocating organs.

Coronavirus disease 2019: Utilizing an ethical framework for rationing absolutely scarce health-care resources in transplant allocation decisions.

The novel coronavirus disease 2019 (COVID-19) is impacting transplant programs around the world, and, as the center of the pandemic shifts to the United States, we have to prepare to make decisions about which patients to transplant during times of constrained resources. In this paper, we discuss how to transition from the traditional justice versus utility consideration in organ allocation to a more nuanced allocation scheme based on ethical values that drive decisions in times of absolute scarcity. We recognize that many decisions are made based on the practical limitations that transplant programs face, especially at the extremes. As programs make the transition from a standard approach to a resource-constrained approach to transplantation, we utilize a framework for ethical decisions in settings of absolutely scarce resources to help guide programs in deciding which patients to transplant, which donors to accept, how to minimize risk, and how to ensure the best utilization of transplant team members.

The impact of the COVID-19 outbreak on liver transplantation programs in Northern Italy.

In January 2020, Novel Coronavirus Disease 2019 (COVID-19) resulted in a global pandemic, creating uncertainty toward the management of liver transplantation (LT) programs. Lombardy has been the most affected region in Italy: the current mortality rate of COVID-19 patients is 18.3% (10 022 deaths; April 10th) with hospitals in Lombardy having to expand the total number of ICU beds from 724 to 1381 to accommodate infected patients. There has been a drastic decrease in liver donors. From February 23rd until April 10th, 17 LTs were performed in Lombardy. Mean donor age was 49 years (range 18-74) whereas mean recipient age was 55 (13-69); mean MELD score was 12 (6-24). All donors underwent screening for SARS-CoV-2 prior to LT. Two patients tested positive after LT, and one patient died for COVID on POD 30. Sixteen patients are alive after an average of 30 days post-LT (range 3-46). 10 patients have been discharged. This study has found no specific reason concerning the safety of recipients, to stop LT programs. Several key lessons from our experience are reported. However, due to the complex circumstances which surround the viral outbreak, the cessation or a reduction in LT activity is a pragmatic requirement.

Donor and transplant candidate selection for solid organ transplantation during the COVID-19 pandemic.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), a novel coronavirus responsible for a worldwide pandemic has forced drastic changes in medical practice in an alarmingly short period of time. Caregivers must modify their strategies as well as optimize the utilization of resources to ensure public and patient safety. For organ transplantation, in particular, the loss of lifesaving organs for transplantation could lead to increased waitlist mortality. The priority is to select uninfected donors to transplant uninfected recipients while maintaining safety for health care systems in the backdrop of a virulent pandemic. We do not yet have a standard approach to evaluating donors and recipients with possible SARS-CoV-2 infection. Our current communication shares a protocol for donor and transplant recipient selection during the coronavirus disease 2019 (COVID-19) pandemic to continue lifesaving solid organ transplantation for heart, lung, liver, and kidney recipients. The initial results using this protocol are presented here and meant to encourage dialogue between providers, offering ideas to improve safety in solid organ transplantation with limited health care resources. This protocol was created utilizing the guidelines of various organizations and from the clinical experience of the authors and will continue to evolve as more is understood about SARS-CoV-2 and how it affects organ donors and transplant recipients.

Utilization of deceased donors during a pandemic: argument against using SARS-CoV-2-positive donors.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly become an unprecedented pandemic that has impacted society, disrupted hospital functions, strained health care resources, and impacted the lives of transplant professionals. Despite this, organ failure and the need for transplant continues throughout the United States. Considering the perpetual scarcity of deceased donor organs, Kates et al present a viewpoint that advocates for the utilization of coronavirus disease 2019 (COVID-19)-positive donors in selected cases. We present a review of the current literature that details the potential negative consequences of COVID-19-positive donors. The factors we consider include (1) the risk of blood transmission of SARS-CoV-2, (2) involvement of donor organs, (3) lack of effective therapies, (4) exposure of health care and recovery teams, (5) disease transmission and propagation, and (6) hospital resource utilization. While we acknowledge that transplant fulfills the mission of saving lives, it is imperative to consider the consequences not only to our recipients but also to the community and to health care workers, particularly in the absence of effective preventative or curative therapies. For these reasons, we believe the evidence and risks show that COVID-19 infection should continue to remain a contraindication for donation, as has been the initial response of donation and transplant societies.

Solid organ transplantation programs facing lack of empiric evidence in the COVID-19 pandemic: A By-proxy Society Recommendation Consensus approach.

The ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has a drastic impact on national health care systems. Given the overwhelming demand on facility capacity, the impact on all health care sectors has to be addressed. Solid organ transplantation represents a field with a high demand on staff, intensive care units, and follow-up facilities. The great therapeutic value of organ transplantation has to be weighed against mandatory constraints of health care capacities. In addition, the management of immunosuppressed recipients has to be reassessed during the ongoing coronavirus disease 2019 (COVID-19) pandemic. In addressing these crucial questions, transplant physicians are facing a total lack of scientific evidence. Therefore, the aim of this study was to offer an approach of consensus-based guidance, derived from individual information of 22 transplant societies. Key recommendations were extracted and the degree of consensus among different organizations was calculated. A high degree of consensus was found for temporarily suspending nonurgent transplant procedures and living donation programs. Systematic polymerase chain reaction-based testing of donors and recipients was broadly recommended. Additionally, more specific aspects (eg, screening of surgical explant teams and restricted use of marginal donor organs) were included in our analysis. This study offers a novel approach to informed guidance for health care management when a priori no scientific evidence is available.