Existing Ethical Tensions in Xenotransplantation

Current Status of Cardiac Xenotransplantation: Report of a Workshop of the German Heart Transplant Centers, Martinsried, March 3, 2023

This report comprises the contents of the presentations and following discussions of a workshop of the German Heart Transplant Centers in Martinsried, Germany on cardiac xenotransplantation. The production and current availability of genetically modified donor pigs, preservation techniques during organ harvesting, and immunosuppressive regimens in the recipient are described. Selection criteria for suitable patients and possible solutions to the problem of overgrowth of the xenotransplant are discussed. Obviously microbiological safety for the recipient and close contacts is essential, and ethical considerations to gain public acceptance for clinical applications are addressed. The first clinical trial will be regulated and supervised by the Paul-Ehrlich-Institute as the National Competent Authority for Germany, and the German Heart Transplant Centers agreed to cooperatively select the first patients for cardiac xenotransplantation.

Xenotransplantation could either be a friend or foe of healthcare equity

Chisholm-Burns et al. discuss the substantial shortage of organs available for transplantation, with disparities in access amongst some racial and ethnic groups. The authors suggest that while xenotransplantation can potentially increase organ availability, it also has the potential to further embed inequities in transplant care.

Ethics, virtues and xenotransplantation

Early in 2022 the first pig to human cardiac xenotransplant was performed. The graft initially performed well, and rejection was well controlled. However, the graft failed, and the patient died 60 days after the procedure. The ethical issues relating to xenotransplantation include the risk/benefit to the individual, the risk of porcine-derived infectious agents crossing into humans, animal welfare and rights, issues of human and animal identity and concerns relating to fair allocation of organs and appropriate use of resources.These ethical issues are often addressed using emotional arguments, or through consequentialist or deontological lens. An alternative is to use approaches based on virtue ethics to understand the moral purpose (telos) of the research and the virtues (character traits) needed to be a good research clinician. In this review we will consider the virtues of justice, courage, temperance and practical wisdom, as well as the role of clinical curiosity, and their application to xenotransplantation. This provides an alternative approach for the clinical academic and others involved in the research to reflect on their practice.

Genetic disenhancement and xenotransplantation: diminishing pigs' capacity to experience suffering through genetic engineering

One objection to xenotransplantation is that it will require the large-scale breeding, raising and killing of genetically modified pigs. The pigs will need to be raised in designated pathogen-free facilities and undergo a range of medical tests before having their organs removed and being euthanised. As a result, they will have significantly shortened life expectancies, will experience pain and suffering and be subject to a degree of social and environmental deprivation. To minimise the impact of these factors, we propose the following option for consideration-ethically defensible xenotransplantation should entail the use of genetic disenhancement if it becomes possible to do so and if that pain and suffering cannot be eliminated by other means. Despite not being a morally ideal 'solution', it is morally better to prevent unavoidable pain until a viable non-animal alternative becomes available.

A fair exchange: why living kidney donors in England should be financially compensated

Every year, hundreds of patients in England die whilst waiting for a kidney transplant, and this is evidence that the current system of altruistic-based donation is not sufficient to address the shortage of kidneys available for transplant. To address this problem, we propose a monopsony system whereby kidney donors can opt-in to receive financial compensation, whilst still preserving the right of individuals to donate without receiving any compensation. A monopsony system describes a market structure where there is only one 'buyer'-in this case the National Health Service. By doing so, several hundred lives could be saved each year in England, wait times for a kidney transplant could be significantly reduced, and it would lessen the burden on dialysis services. Furthermore, compensation would help alleviate the common disincentives to living kidney donation, such as its potential associated health and psychological costs, and it would also help to increase awareness of living kidney donation. The proposed system would also result in significant cost savings that could then be redirected towards preventing kidney disease and reducing health disparities. While concerns about exploitation, coercion, and the 'crowding out' of altruistic donors exist, we believe that careful implementation can mitigate these issues. Therefore, we recommend piloting financial compensation for living kidney donors at a transplant centre in England.

Xenotransplantation Clinical Trials and Equitable Patient Selection

Xenotransplant patient selection recommendations restrict clinical trial participation to seriously ill patients for whom alternative therapies are unavailable or who will likely die while waiting for an allotransplant. Despite a scholarly consensus that this is advisable, we propose to examine this restriction. We offer three lines of criticism: (1) The risk-benefit calculation may well be unfavorable for seriously ill patients and society; (2) the guidelines conflict with criteria for equitable patient selection; and (3) the selection of seriously ill patients may compromise informed consent. We conclude by highlighting how the current guidance reveals a tension between the societal values of justice and beneficence.

Ethical Aspects of Human Induced Pluripotent Stem Cells and Alzheimer's Disease: Potentials and Challenges of a Seemingly Harmless Method

Dementia currently affects more than 55 million people worldwide, and scientists predict that this number will continue to rise. The most common form is Alzheimer's disease (AD), which is triggered, among other things, by dysfunctional cells in the human brain. Stem cell research attempts to counteract neurodegenerative processes, for example by replacing or treating diseased cells. In addition to human embryonic stem cells, since the successes of Takahashi and Yamanaka in 2006, there has been an increased focus on human induced pluripotent stem cells (hiPS cells). These cells avoid ethically challenging questions about the moral status of human embryos, but there are numerous problems, such as high production costs, side effects from the reprogramming process, or a potentially new moral status. These ethical issues will be examined primarily in relation to AD. The first part will be a discussion of hiPS cells and their importance for stem cell research, after which the focus turns to AD. Based on scientific studies, the relationship between hiPS cells and AD will be outlined as well as ethical implications presented. While potential limitations of hiPS cells have been discussed by numerous authors, an ethical perspective on the link between hiPS cells and AD seems to be neglected in the scientific community. The following risk analysis aims to identify a possible research agenda. In conclusion, the focus on individuals with AD may help to adopt an ethical stance that recognizes existing limitations and constructively engages with the possibilities of research.

What Do Chimeras Think About?

Non-human animal chimeras, containing human neurological cells, have been created in the laboratory. Despite a great deal of debate, the status of such beings has not been resolved. Under normal definitions, such a being could either be unconventionally human or abnormally animal. Practical investigations in animal sentience, artificial intelligence, and now chimera research, suggest that such beings may be assumed to have no legal rights, so philosophy could provide a different answer. In this vein, therefore, we can ask: What would a chimera, if it could think, think about? Thinking is used to capture the phenomena of a novel, chimeric being perceiving its terrible predicament as no more than a laboratory experiment. The creation of a thinking chimera therefore forces us to reconsider our assumptions about what makes human beings (potentially) unique (and other sentient animals different), because, as such, a chimera's existence bridges our social and legal expectations about definitions of human and animal. Society has often evolved new social norms based on different kinds of (ir)rational contrivances; the imperative of non-contradiction, which is defended here, therefore requires a specific philosophical response to the rights of a thinking chimeric being.

In defense of xenotransplantation research: Because of, not in spite of, animal welfare concerns

It is envisioned that one day xenotransplantation will bring about a future where transplantable organs can be safely and efficiently grown in transgenic pigs to help meet the global organ shortage. While recent advances have brought this future closer, worries remain about whether it will be beneficial overall. The unique challenges and risks posed to humans that arise from transplanting across the species barrier, in addition to the costs borne by non-human animals, has led some to question the value of xenotransplantation altogether. In response, we defend the value of xenotransplantation research, because it can satisfy stringent welfare conditions on the permissibility of animal research and use. Along the way, we respond to the alleged concerns, and conclude that they do not currently warrant a cessation or a curtailing of xenotransplantation research.

The Influence of Interdisciplinary Work towards Advancing Knowledge on Human Liver Physiology

The knowledge accumulated throughout the years about liver regeneration has allowed a better understanding of normal liver physiology, by reconstructing the sequence of steps that this organ follows when it must rebuild itself after being injured. The scientific community has used several interdisciplinary approaches searching to improve liver regeneration and, therefore, human health. Here, we provide a brief history of the milestones that have advanced liver surgery, and review some of the new insights offered by the interdisciplinary work using animals, in vitro models, tissue engineering, or mathematical models to help advance the knowledge on liver regeneration. We also present several of the main approaches currently available aiming at providing liver support and overcoming organ shortage and we conclude with some of the challenges found in clinical practice and the ethical issues that have concomitantly emerged with the use of those approaches.