Xenotransplantation, the transplantation of cells, tissues or organs of other species into human patients, has become increasingly researched as a way to save patients on the transplant waiting list that may not have the time to wait for a suitable human organ transplant. With the worldwide shortage of human organs suitable for medical implantation, around 20-35% of patients in need of replacement organs will die while on the waiting list.[1] If xenotransplantations become medically possible, many of these lives can be saved.

While the benefits of xenotransplantation are clear, should it ever go beyond medical research and become a routine medical procedure, there are many ethical issues that must be addressed as well. The main issue that I will focus on in this article is greater societal impact that xenotransplantation may have due to the risk of spreading a cross-species disease. This is especially important, as it involves striking a balance between the rights of the individual and the importance of protecting society as a whole.

There has yet to be an entirely successful case of a xenotransplantation due to the human body’s natural response to fight against foreign substances and cells.[2] The negative backlash from an organ transplant patient’s immune system is challenging enough to deal among same-species transplantation, let alone the repercussions that a patient faces from xenotransplantation. Furthermore, in the past, xenotransplantations were occasionally carried out without the informed consent of the patients, leading to a negative view of the research.[3] Nevertheless, as doctors are gaining greater insight into suppressing the native negative immune response, research in xenotransplantation has continued.[4]

While patients must always give informed consent before a procedure is undertaken, as well as given autonomy in their own decision, due to the potential public dangers that xenotransplantation can pose, it is necessary to consider whether their personal autonomy in deciding to have the transplant, is more or less significant than the risk of the spread of a new, foreign, disease that could impact not only their life, but the lives of their loved ones, and even other strangers. It becomes a question of saving one person, but potentially endangering hundreds or thousands of people, even possibly setting off an epidemic. While the idea of a single individual’s xenotransplantation having such widespread consequences may seem an exaggeration, it is a very real risk.

With xenotransplantation comes the possibility of xenozoonosis, which is the transmission of infectious agents between species via xenograft. These diseases that originate in non-human organisms are also known as zoonoses.[5] They are particularly dangerous because humans tend to have little immunity towards them, and the response time against these illnesses is generally slower because they tend to be unrecognized, new illnesses. Some well-known examples of zoonoses are avian flu, swine flu, Ebola and the West Nile virus.

Thus, this possibility of cross-species infection not only poses a danger to the transplant patient, but also to his or her family and friends. On an even larger scale, it poses a danger to the greater public as well. Given this risk of the spread of a foreign infectious disease, should the patient’s family and close friends also be required to give consent before a xenotransplantation can take place? If so, does this infringe upon a patient’s autonomy in making his or her medical decisions? And once again, to consider the greater public implications of xenozoonosis, how can we both protect the interests of the patient, as well as that of the public as a whole?

While cross-species organ transplantation has not yet been practiced clinically, xenografts, surgical grafts of tissues or cells from a foreign species, have been done on burn victims and diabetics.[6] The current policy in the United States for reducing the risk to public health from xenografts is that patients must be monitored for the rest of their life and are not given the choice to withdraw from monitoring.[7] While this policy may significantly reduce the likelihood of any accidental transmission of a zoonotic disease, it then infringes upon a patient’s right to privacy and freedom, raising the question of whether the right of privacy and autonomy of one individual is more or less important than general public safety?

Once again, the discussion boils down to the right of an individual and the right of society as a whole. For xenograft patients, in exchange for their right to undergo the procedure, they must give up part of their personal privacy in order to better protect the general public. This is the deal that they have chosen to strike. Thus, it is important not only to make clear to patients the dangers that a xenotransplantation has both to them and to the wider population, but that should they undergo such a procedure, there will be a limitation placed on their freedom in the future.

Clearly, while xenotransplantation is a promising alternative to the long organ transplant waiting list, there remains much room for discussion regarding how it will impact not only patients, but the general public as well. If the trend of xenograft patients extends to xenotransplantation patients, while the right to undergo the medical procedure may remain with the patient, they will have to sacrifice some part of their autonomy for the safety of the populace.

[1] Healy, D. G.; Lawler, Z.; McEvoy, O.; Parlon, B.; Baktiari, N.; Egan, J. J.; Hurley, J.; McCarthy, J. F.; Mahon, N.; Wood, A. E. (2005). “Heart transplant candidates: Factors influencing waiting list mortality”. Irish medical journal 98(10): 235–237.

[2] Cooper DKC. A brief history of cross-species organ transplantation.Proceedings (Baylor University Medical Center). 2012;25(1):49-57.

[3] Ibid.

[4] History of xenotransplantation | Biotech Learning Hub. Biotechnology Learning Hub RSS 2011. Available at: http://biotechlearn.org.nz/themes/xenotransplantation_and_organ_donation/history_of_xenotransplantation. Accessed March 2, 2016.

[5] Zoonoses and the Human-Animal-Ecosystems Interface. WHO. Available at: http://www.who.int/zoonoses/en/. Accessed March 2, 2016.

[6] Elliott RB, Living Cell Technologies Towards xenotransplantation of pig islets in the clinic. Curr Opin Organ Transplant. 2011;16(2):195–200. [PubMed]

[7] U.S. Food and Drug Administration. PHS Guideline on Infectious Disease Issues in Xenotransplantation 2014. Available at: http://www.fda.gov/biologicsbloodvaccines/guidancecomplianceregulatoryinformation/guidances/xenotransplantation/ucm074727.htm. Accessed March 2, 2016.