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March 1997 Xenotransplants: Animals as Spare Parts By Alan H. Berger

Xenotransplantation- the transfer of organs between species- has been hailed by scientists as a breakthrough solution to the chronic shortage of human organs. Ethicist Alan Berger begs to differ.

Transplanting organs such as hearts, lungs, kidneys, etc. from human donors to human patients seems commonplace today. Unfortunately, as we all know, there is an increasing demand for these prized organs and a seemingly limited supply; currently, there is a patient list of approximately 45,000 and an annual supply of only 20,000 organs.

Our current system of human organ procurement for transplantation is not working. Only about 20% of potential organ donors who die "healthy" have arranged for their organs to be used to help others. This seems remarkable given 1993 Gallop Poll results: 85% of individuals supported the donation of organs for transplant and 69% were very likely or somewhat likely to want their organs donated after their death; 93% were willing to donate a family member's organs if requested before death, but only 47% if the issue was not discussed before death.

The response from the medical community is to consider animals as major organ donors. Without pausing to further evaluate the serious flaws in this practice, known as xenotransplantation, as well as the ethical dilemmas in cross-species transplants, the alternatives available, and the role of the biotech industry, it is going full speed ahead.

The Problem of Cost

In 1994, nearly $3 billion was spent on organ transplants. This cost does not include expensive follow-up care for the thousands who have already received transplants. As a society, we already have serious difficulties justifying the cost of human organ transplants. With a growing number of people lacking access to basic health care, it may not be justifiable even today to devote so much energy and financial resources to human organ transplants.

With xenotransplantation, the costs are even higher. According to the Institute of Medicine (IOM) in their June 1996 report, Xenotransplantation: Science, Ethics and Public Policy, this cost could rise to $20.3 billion if all patients in need of organs received xenotransplants. Furthermore, the success rate is zero, health insurance is not available and the procedure annually benefits only a small number of people. It seems inappropriate to use limited research dollars on this type of experimental surgery when these same dollars can be used more appropriately for better methods of treatment and prevention.

One common response is that it is not possible to measure the value of a human life simply by cost. Unfortunately that is just not true. Costly medical procedures to a limited, chosen group will continually raise the cost of health care overall, limit insurance coverage and increase insurance premiums. The result is that more and more people will not find adequate health care services available to them. Do we save some patients with expensive medical procedures, and possibly lose even more by denying them access to basic health care?

The Problem with Animals

Until recently the "animal of choice" has been the baboon. The available non-human primates are limited in number, expensive, difficult to maintain and rarely Specific Pathogen Free (SPF). The current trend is to use transgenic pig organs for human transplant recipients. "Sacrificing" a baboon, an animal much closer to humans, is harder for many people to accept than using organs from an animal whose parts are already used for servicing human needs. To reduce their exposure to disease, these genetically altered pigs are removed from the womb by Cesarean section, never allowed to suckle or even come in contact with their mother, hand-raised by humans wearing gloves, and maintained in a semi-sterile environment.

The Problem of Disease

Perhaps the greatest risk xenotransplantation poses is exposing human populations to non-human primate viruses, and this possibility of transmission of a lethal virus has convinced many researchers to abandon primate-to-human transplants. It is now believed in the scientific community that HIV, already a worldwide catastrophe affecting as many as 20 million people, was a simian virus passed on to the human population.

There are no tests currently available to screen for all animal-specific diseases and a lethal unknown virus can escape our vaccination and testing programs. The risk may even be higher if a xenotransplant actually succeeds and the patient lives a "normal" life. Even though the risk may be small, the outcome of a new virus spreading can be catastrophic. Even if pigs are SPF, this does not guarantee human safety from infectious diseases. The assumption that swine used in xenotransplantation are safer donors has not been proven. The new strains of swine flu that periodically appear may become more pronounced if pigs are used as organ donors for humans.

Professor Frederick Murphy, a virologist at the University of California, has issued a warning about the risk of spreading diseases to humans in proposed transplants of transgenic pig organs. There are four thousand known virus species and 30,000 strains and variants that infect living creatures. Trying to identify potentially lethal viruses that might be transmitted to humans during a xenotransplant would be nearly impossible.

The Problem of Ethics

The ethical, moral, philosophical and religious concerns over the creation of a "new" species-especially one that is "almost" human- need to be seriously addressed. Is this what we as a society really want? Where does it end? Who controls this process? How human would a transgenic pig be? When does a "non-human" with human genes become human, deserving full human rights? What if our genetic tampering misfires- what have we created? The larger ethical question is the lesson we are presenting to future generations. Our society does not have a reverence for all life. Indeed, many feel that our careless disregard for all living things assisted in the development of our increasingly violent society.

The Problem of Government

On September 20, 1996 the Department of Health and Human Services (HHS) released proposed guidelines for xenotransplantation, developed with the Food and Drug Administration (FDA), the Centers for Disease Control and Prevention (CDC), and the National Institutes of Health (NIH). The HHS recommendations included: taking appropriate safety measures to screen animals for diseases; archiving biological samples from the source animals and transplant recipient; expanding transplant teams for specific expertise and conducting appropriate research; having local review boards evaluate infectious disease risks; and monitoring patients after xenotransplants for infectious disease agents.

These guidelines, however, pave the way for a potential public health disaster. First, they warn that infectious agents "may not produce clinically recognizable disease until many years after they enter the host and some infectious agents are not readily detected or identified in tissue samples by current diagnostic techniques." Secondly, they add that "the full spectrum of infectious agents potentially transmitted via xenograft transplantation is not well known. Infectious agents that produce minimal symptoms in animals may cause severe morbidity and mortality in humans." To make us feel even more nervous they use the example of AIDS/HIV to demonstrate that "persistent viral infections may result in person-to-person transmission for many years before clinical disease develops..., thereby allowing an emerging infectious agent to become established in the susceptible population before it is recognized."

With the estimate from the IOM report of potentially over 100,000 xenotransplants annually, the surveillance system being established to protect the public is not financially or physically possible. In addition, it kicks in only after the xenotransplant occurs,žwhen it may be too late. The suggestion that local medical center review boards can monitor xenotransplantation surgical protocols (including surveillance guidelines) to keep them consistent is unworkable. The HHS seems interested in accelerating the process and pushing as much of the oversight as possible down to the local levels, a poor decision at best.

The Problem of Fame

I believe that most xenotransplant researchers are sincerely interested in saving human lives, rather than the fame or financial rewards that might accompany research success. But how driven are these very same people by the need for bringing funding dollars to their research institution? Or are they so driven by "finding the solution" that other considerations become secondary? Can these very same people be the ones making ethical and scientific decisions over their own experimental medical procedures? There is a definite conflict of interest here, and a strong need for more independent public oversight. And what about the biotech industry? This is already a multi-billion dollar enterprise. Will and do dollar bills outweigh the public good?

Alan Berger is the Executive Director of the Animal Protection Institute. This article is an excerpt of a speech given at the National Conference of Applied Ethics and soon to be published in the proceedings from the conference. For further information on API, contact: P.O. Box 22505, Sacramento, CA 95822. Tel.: 916-731-5521.

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