The Science, Ethics and Politics of Contemporary Xenotransplantation

Abstract

Due to the shortage of human donor organs and tissues, xenotransplantation has been championed as an alternative for patients with critical organ and tissue failure. For example, porcine islet transplantation could treat exocrine pancreatic insufficiency in Type 1 diabetes. Through a case study on Type 1 diabetes, this thesis highlights the therapeutic promise and scientific, clinical, ethical and regulatory challenges of clinical xenotransplantation. In clinical trials to date, porcine islet transplantation temporarily restored endogenous insulin production in a subset of patients however long-term efficacy remains to be achieved. Xenotransplantation also faces the significant barriers of immune rejection and xenozoonosis – the transmission of infectious agents from porcine grafts to human hosts, their close contacts and the broader community. Yet groundbreaking gene editing technologies like CRISPR/Cas9 could allow production of xenografts that are less immunogenic and pose minimal risk of xenozoonosis. There are also ethical concerns that clinical xenotransplantation undermines the moral status of animals and the personal liberties of xenograft recipients who are subjected to lifelong surveillance. However, these issues are not unique to xenotransplantation and parallels may be drawn with synthetic biology, another emerging biotechnology. As Australia develops a regulatory framework for xenotransplantation research, the uncertainty surrounding the public health risks suggests that a precautionary approach should be adopted. And although xenotransplantation research is fraught with scientific, clinical and ethical challenges, this should motivate policy makers and other stakeholders to devise innovative regulatory mechanisms that enable it to proceed in a safe and ethically defensible manner. As is the case with other emerging biotechnologies like stem cell therapy, it may take several decades before the full potential of xenotransplantation is realised.