Xenotransplantation: Philosophical Reflections And Ethical Issues

The remarkable half-century transition of organ transplantation from experimental intervention to standard clinical practice has, on one hand, made alleviating many incurable diseases possible, on the other hand, resulted in a growing disparity between the number of persons who could potentially benefit from allotransplants and the availability of transplantable human organs. In the statistics taken by USA, Canada, UK and the Council of Europe, we can see something in common, that is, as the gradual growth of transplants, the number of patients on the waiting list increases more rapidly and leads to the huge gap between the supply and the demand. There are many difficulties in managing to enlarge the source of transplantable human organs as well as developing artificial organs or mechanic devices to resolve these disparities, so it occurs to transplant surgeons' mind that we can use animal organs. Due to easy availability and lower price of animal organs, if they can be clinically used for human transplants, it can change the status quo of the scarce of transplantable organs. In brief, xenotransplantation refers to the transplantation of animal cells, tissues or organs into human body. Currently xenotransplantation confronts two main problems, that is, immune rejection and cross-species infection. With the development of transgenic and gene knock-out technology, researches on immune rejection have made a great progress. However, cross-species infection might be more serious problem, which we can't quantify but which we know is greater than zero. Xenotransplantation can provide a more convenient way for the close contact of human and animal viruses and animal viral infection in human by transplanting animal cells, tissues and organs into human body. How to make the risk/benefit analysis in xenotransplantation technology? Is the risk to the public justified by the help we are going to give individual patients? What's more, xenotransplantation technology also raises the following ethical issues: the issue of the use of animals, the issue of distributive justice in health resource allocation, as well as the issue of human identity and integrity, and so on. I will take the principle-based approach to analyze and resolve these ethical issues, that is, firstly constructing ethical principles and normative system applied to the specific technology, and then evaluating the activities in this field. Ethical principles applied to specific scientific activities are more focalizing than constructed in general applied normative ethics. Aiming at the features of xenotransplantation which is the rather dangerous technology of the application of genetic engineering, I tries to construct the following nonfoundational principles which comes from the ethics of responsibility, ecological ethics and general normative ethics and incorporates the core values of traditional Confucian ethics and contemporary communitarian ethics, that is, responsibility, integrity, solidarity, justice, utility and respect for person. Before analyzing and resolving the ethical issues raised by xenotransplantation technology, I plan to examine and explore the philosophical discussion regarding the two issues which are correlative to the evaluation of xenotransplantation technology, that is, the relationship between human being and nature, especially between human and animals, as well as human nature. We can demonstrate the theoretical premise of analyzing and resolving ethical issues unless we make the debates over these two issues clear and explicitly state the position we hold. Risk/benefit analysis is the most controversial ethical issues raised by xenotransplantation technology. First of all, we need know the complexity of risk/benefit assessment in xenotransplantation technology. We should distinguish the risks to different groups, for example, risks to research subjects/patients, to their close contacts, to their families, communities and even the entire population. In addition, we should identify different type of risks, for example, physical risks, psychological risks, social risks, economic risks and legal risks. As for benefit analysis, we should classify different benefits, for example, therapeutic benefit, scientific benefit and commercial benefit. It iscrucial to pay more attention to xenotransplantation research which is driven by mere commercial benefit, and to point to the source of conflict of interests. Unlike the identification of risks and benefits, and estimates of their magnitude and probability of being realized, the final step, determining the risk-benefit ratio, is a moral judgment. Due to so many uncertainties in xenotransplantation research, "guilty upon proven innocent" strategy is the suitable method of risk analysis and reduction. Is the risk to the public, which we can't quantify but which we know is greater than zero, justified by the help we are going to give individual patients? This issue is, ultimately, an ethical issue, but rather a technical issue. It will challenge the current ethical framework for clinical research on humans, and make us reconsider the very old and controversial ethical issues, that is, the relationship between individual and group, more precisely, individual interest vs. social interest, or individual liberty vs. public good. If we can't resolve this issue reasonably, the advancement of xenotransplantation technology will miss the right direction, and even lead humans into disaster. Xenotransplantation research also raises the following ethical issue, that is, with which way and to what extent it is reasonable that we make use of animals as the source of transplantable tissues and organs? Even if people accept in principle the use of animals in medicine and medical research, their use in xenotransplantation may raise particular difficulties which need to be discussed further. For example, whether as a matter of principle, it is considered to be morally acceptable to use animals as organ or tissue source; the ethical acceptability of the use of primates to supply transplant material; the ethical issues raised by the use of genetically modified animals to provide organs for xenotransplantation. In the context of the scarcity of health resources, xenotransplantation research will compete with other health plans or research projects related to primary health care which should be made priorities. The status quo in China at present is the coexistence of the scarcity and the waste of health resources. Under this circumstance, how many high-techhealth services and medical researches should be provided and conducted in China? In this context, we'd have to respect the reality of scarce resources, but we also should emphasize and implement the equality-based distributive principle, which hold the neutral all-purpose means to a good life and basic needs every citizen shares as the highest value. Even if xenotransplantation technology were proven to be safe and effective, it still challenges the integrity and inherent value of the human person and human species. Xenotransplantation may be viewed as further contributing to the dehumanization or artificialization of the human person and body. As xenotransplantation involves cells, tissues or organs from another species, it questions the very "nature" of what makes us human. The technology of gene transfer has made it possible that DNA may be largely shared between species, this transfer between species raises fundamental issues of who we are and where we are on the evolutionary scale. We should understand and interpret human as the unity of natural and social/spiritual attributes. When more and more biotechnologies directly intervene into human genome, the human species might soon be able to take its biological evolution in its own hands, we should keep in mind not to ignore natural attributes and biological traits of human species by overemphasizing social and cultural attributes. The above issues belong to substantial ethical questions. Substantial ethics aims to resolve the issues regarding what should be done, procedural ethics aims to how should be done. On the basis of the above ethical analysis and arguments, I draw the conclusion that xenotransplantation research is ethically permissible, that is, the transplantation of animal organs can be used as the interim procedure of allotransplantation; the transplantation of animal cells or tissues can be the therapeutic method of severe diseases without effective therapies currently. When xenotransplantation is proven not to cause cross-species infection with solid evidences, it can move into clinical trials. We should consider the following ethical issues in the procedure of clinical research: the complexity of informed consent, the selection of human subjects in early clinical trials, as well as animal welfareissues. Last but not least, on the basis of resolving these ethical issues, I propose some brief recommendations regarding public policy on xenotransplantation technology.