What's Wrong With Xenotransplantation?
An Animal Rights Article from All-Creatures.org


Campaign for Responsible Transplantation (CRT)
July 2009

Merriam-Webster: Xenotransplantation is the transplantation of an organ, tissue, or cells between two different species

Why CRT is Opposed to Xenotransplantation

The alleged chronic shortage of human organs has led some researchers and federal health officials in the US and elsewhere to consider using organs from animals such as pigs and nonhuman primates. Xenotransplantation, attempted since 1905, is marred by a history of failures and intense human and animal suffering. But the prospect of commercializing the technology has created huge financial incentives for biotechnology and pharmaceutical companies who have invested hundreds of millions of dollars in xenotransplantation. The desire to gain a return on such large investments has led many companies to make exaggerated claims about the alleged merits of the technology. CRT believes that these claims are baseless and that, in fact, the technology is dangerous, expensive, inhumane, and unnecessary, and should therefore be banned.

Scientific/Medical Concerns

  • Transplanting living animal organs into humans circumvents the natural barriers (such as skin and gastrointestinal tract) that prevent infection, thereby facilitating the transmission of infectious diseases from animals to humans.
  • Many animal viruses have the ability to jump species barriers and kill humans. Viruses that are harmless to their animal hosts, can be deadly when transmitted to humans. For example, Macaque herpes is harmless to Macaque monkeys, but lethal to humans.
  • Many viruses, as innocuous as the common cold or as lethal as Ebola, can be transmitted via a mere cough or sneeze. An animal virus residing in a xenograft recipient could become airborne, infecting scores of people, and causing a potentially deadly viral epidemic of global proportions akin to HIV or worse.
  • Pigs, genetically altered to carry human genes, are being considered as the source animals of choice for xenotransplants, despite the existence of over 25 diseases in pigs that can infect humans. The influenza virus of 1918, which resembled a common swine flu, killed more people in modern history than any other epidemic including AIDS and the Black Plague. New mutations of swine influenza are being seen around the globe, and novel pig viruses keep surfacing. In October 1997, medical journals reported that Porcine Endogenous Retroviruses (PERVs), present throughout the pig genome, infected human cells in test tubes. That same year, the Australian "paramyxovirus" infected piggery workers with flu-like symptoms. And, most recently, the "Nipah" virus, discovered in Malaysia in late 1998, spread from pigs to hundreds of humans, killing 100+ and leading to the mass slaughter of some one million pigs, as well as several dogs and horses.
  • There is no way to screen for viruses that are not yet known. Proceeding with xenotransplantation could expose patients and non-patients to a host of new animal viruses which could remain dormant for months or years before being detected. Xenotransplantation could thus be viewed as a form of involuntary human experimentation which violates US laws and United Nations charters.
  • Xenotransplant proponents claim that they will breed "germ-free" animals, thereby diminishing the risk of viral transmission. But it is impossible to breed "germ-free" animals since no animal can remain completely free of parasites or endogenous viruses. In fact, genetically engineered animals are more susceptible to a host of diseases because of weaker immune systems.

Social Concerns

  • CRT believes that HHS violated the Public Health Service Act by ignoring the scientific evidence showing that xenotransplantation is dangerous and ineffective. HHS failed to adequately consider the legal, social, ethical, and economical implications of xenotransplantation. HHS issued voluntary draft guidelines on xenotransplantation, September 23, 1996, despite scientific evidence demonstrating that the xenograft recipient will suffer significant harm. Scientists have criticized the voluntary guidelines for being weak, ineffectual, and unlikely to protect the public. HHS did not adequately consider how to protect the public from contracting novel animal viruses, how to deal with the issue of informed consent, or the large costs associated with xenotransplantation. HHS issued voluntary guidelines to regulate the technology. It is highly probable that HHS will be unable to protect the xenograft recipient or the public from being infected by an animal virus. As a result, HHS should have considered how the government would handle an infectious epidemic before the guidelines for xenotransplantation were issued.
  • HHS has not addressed how infected individuals will be identified and how those infected will be prevented from spreading diseases. HHS has also failed to address who will pay for treatment and care for those infected. Treating and caring for individuals infected with animal viruses will most likely cost the U.S. billions of dollars. So far, HHS has not stated whether it would compensate victims who inadvertently come into contact with a lethal animal virus. However, this should be a consideration because the government has already had to respond to compensation claims filed by Persian Gulf War veterans, victims of Agent Orange, hemophiliacs infected by HIV-tainted blood, and parents of vaccine-damaged children. Although HHS identifies procedures for obtaining informed consent in the xenotransplantation guidelines, the agency failed to consider several important issues. An Institute of Medicine 1996 report on xenotransplantation indicates that "more research needs to be done on the psychological, religious, and social interpretations of xenotransplants for patients and their families." HHS should have considered that xenograft patients will most likely be very ill when they decide to take part in xenograft procedures. These patients, many in desperate situations, must understand highly complex issues, including the experimental nature of xenotransplantation and the health risks not only to themselves, but also their close personal contacts. It is unlikely that patients would fully understand the consequences of their participation in such experiments.
  • Health authorities were unable to prevent the worldwide spread of HIV infection. Similarly, they were unable to prevent Ebola outbreaks in Sudan, Zaire (1976, 1979, 1995) and the US (1989, 1996). Furthermore, there is evidence that humans have become ill after consuming or being injected with animal materials. There is a reported link between the smallpox vaccine (derived from animal cells) and AIDS, a recently acknowledged link between human lung, brain and bone cancer and the SV (simian virus) 40 (found in old batches of the Salk polio vaccine), and the threat of emerging infectious diseases, including human Creutzfeldt-Jakob Disease (CJD) from the consumption of "mad cows" in Europe, the Netherlands, and the US. It would be a tragedy if federal health authorities failed to respect the precautionary principle and facilitated the introduction and spread of a new viral epidemic. Responsible health authorities would steer clear of xenotransplantation in the interest of human health.

Regulatory Issues

  • In September 1996, the Department of Health and Human Services (HHS) issued a set of draft voluntary guidelines on xenotransplantation. Currently, xenotransplantation is "regulated" by the Food and Drug Administration (FDA); Over the last several years, FDA has approved limited clinical trials with animal tissues, cells, and organs, typically pig livers, used outside the body as temporary "bridges" to "filter" the blood of patients awaiting human liver transplants. Xenotransplant products that utilize both a device and a biologic (such as the "liver-assist device") would be considered a combination product and regulated both by the FDA's Center for Biologic Evaluation and Research (CBER) and the Center for Drug Evaluation and Research. Animal organs used in xenotransplantation would be considered biologics and covered by CBER. Ironically, CBER scientists have acknowledged that xenotransplantation presents a risk of introducing novel pathogens into the human population.
  • The FDA's active support for xenotransplant research is inconsistent with positions the agency has taken in the past. In 1991, the FDA ordered a recall of a disinfectant, Sporicidin, used by dentists and doctors to sterilize equipment, claiming that it did not adequately protect patients from infectious microorganisms. FDA commissisoner at the time, David Kessler, said FDA would "not tolerate products that would permit the transmission of disease from one patient to another."
  • Proposed regulatory oversight of xenotransplantation procedures is weak and would likely be highly flawed. Although xenotransplants subject patients and non-patients to significant health risks, HHS chose a lenient method for monitoring the health effects from the procedures by constructing voluntary guidelines on xenotransplantation. As it stands, the guidelines are to be "enforced" at the local level by institutional review boards (IRBs). Virologist Jonathan Allan has stated that, "in choosing voluntary guidelines to be enforced at a local level [via IRBs],…the FDA/CDC committee has chosen the least stringent and possibly least successful method of policing these transplant procedures."
  • In a draft 1998 report, the HHS's own Inspector General June Gibbs Brown said that institutional review boards, whose members are unpaid, and who are charged with monitoring the treatment of participants in clinical trials, "face crushing workloads, inadequate training and potential conflicts of interest."
  • Even if FDA were to assume the responsibility for monitoring all clinical xenotransplant trials, that would not necessarily be an improvement. FDA has already failed to successfully provide oversight for human tissue banks; the agency has also been criticized by scientists and consumer groups for approving the use of a controversial genetically engineered bovine growth hormone despite the existence of several studies questioning its safety.
  • In the federal guidelines, HHS recommends a strict monitoring regimen for patients and their close contacts. The rigorous and potentially "life-long surveillance" program, would require complete physical exams and sampling regimens. But HHS fails to discuss the issue of noncompliance with the monitoring program. What would happen if individuals choose to sporadically participate or entirely withdraw from the program and HHS is not able to detect an infectious disease? A disease could spread before HHS recognizes its existence.
  • In all areas of human activity, particularly when money is involved, the potential for fraud, error, and negligence exists. In the past, such behavior has placed human health at considerable risk. Witness the HIV-contaminated blood scandals in France, China, Japan and the US, for example, in which employees and/or medical authorities knowingly allowed HIV-contaminated blood to be used for transfusions and blood-clotting treatments for hemophiliacs.
  • Given the enormous amount of data, paperwork, and filing xenotransplant procedures would generate, it would be naive (given human nature) to assume that data will be properly recorded, stored, reviewed, and updated. Regulatory mechanisms often fail to prevent or correct these errors and/or behaviors, the consequences of which could be disastrous in the face of a xenogeneic infection.

Economic Concerns

  • Xenotransplantation is not a cost effective technology. It is riskier and promises to be even more expensive than human-to-human transplantation (roughly $300,000 per operation, not including the hidden costs of breeding, housing, feeding, medicating, testing, transporting, rendering, and disposing of the waste and remains of herds of transgenic animals).
  • The FDA wants to establish a registry to archive xenograft patient and source animal tissue samples. This archive is to be funded by taxpayers. FDA officials estimate the cost of the registry at $250,000 to $300,000 a year, and the cost for the archive at $1 million a year.
  • Xenotransplant researchers acknowledge that 'rearing pigs under germ-free conditions, is extremely expensive and time-consuming and the production of germ-free pigs would greatly add to the cost of providing donor organs.' Currently it costs from $25,000 to $100,000 to test just one pig for the presence of known bacteria and viruses. The biotechnology company Nextran explains that one of its pig organs will eventually cost the same as a human organ.
  • Based upon this estimate, xenotransplantation is not cost effective.
  • The current transplant costs for human organs range from $116,000 for a kidney to more than $300,000 for a liver. Factoring in years of follow-up care and immunosuppressive drugs, the cost rises to about $400,000 for a liver transplant and over $300,000 each for heart and lung transplants. A 1996 Institute of Medicine report predicts that xenotransplantation will push annual transplant cost from $3 billion to $20.3 billion. These costs are beyond the means of a majority of Americans and an already overburdened health care system.
  • It is predicted that, by the year 2000, 48 million Americans will lack basic healthcare. Another 30+ million will be underinsured. The uninsured (largely minorities, 18 to 24-year-olds, and the working poor) who are chronically ill are least likely to receive proper care, with the result that untreated conditions can lead to serious health consequences. Can we justify spending hundreds of thousands of dollars on operations that, if they ever succeed, would at best benefit a small minority of patients, while dramatically driving up health care costs for all?

Animal Welfare Concerns

  • Biotechnology companies are breeding pigs with human genes in the hopes of fooling the human immune system into accepting a foreign organ from another species. This disturbing genetic reconstruction of life (the creation of animals that are, in essence, part animal and part human) is advancing on a commercial scale with almost no informed public discussion or effective oversight.
  • Scientific studies have demonstrated that pigs are highly intelligent and sensitive animals. Pigs used in studies at the University of Pennsylvania manipulated joysticks with their mouths to solve mazes and play games on a computer. Pigs used in biomedical research can be subjected to painful biological and surgical manipulations at experimenters' discretion, causing great pain and suffering before death. Policy-makers in the U.S. and elsewhere have decided that it is "ethical" to use pigs in xenotransplants because pigs are killed for food. But two wrongs do not make a right. Ironically, it is precisely because people eat too many pigs, and have unhealthy lifestyles, that pig organ transplants are being considered. A large majority of heart, liver, and kidney transplants could be prevented if people reduced their meat, (and alcohol and tobacco consumption). We should ask whether it is acceptable to make pigs and other nonhuman animals scapegoats for our species' self-destructive behaviors. Transgenic technology is very imprecise. Previous transgenic pig research programs have produced animals with various painful physical abnormalities including arthritis, stomach ulcers, muscular weakness, defective vision, and weakened immunity. Transgenic animals are destined to spend their lives confined in unnatural, sterile environments, unable to fulfill their basic behavioral needs, until death. In her book, Genetic Engineering: Dream or Nightmare (1998), British biologist Mae-Wan Ho wrote that, "the creation of transgenic animals for xenotransplantation . . .[is] scientifically flawed and morally unjustifiable. [It carries] inherent hazards in facilitating cross-species exchange and recombination of viral pathogens. These projects ought not to be allowed to continue without full public review."

Environmental Concerns

  • In CRT's opinion, HHS failed to consider the environmental consequences of xenotransplantation as required by the National Environmental Policy Act (NEPA). HHS issued guidelines for xenotransplantation without complying with any of NEPA's requirements. NEPA requires that agencies "take a 'hard look' at the environmental consequences before taking a major action." HHS failed to take the required "hard look" at the environmental and health consequences of its actions because no Environmental Impact Statement (EIS) was performed. By completely ignoring the entire EIS requirements, HHS has violated NEPA.
  • CRT believes that xenotransplantation is a "significant" action because it is highly controversial and poses unique and unknown health effects to the xenograft recipient and the general public. Furthermore, xenotransplantation affects "the quality of the human environment." Federal regulations define "the quality of the human environment" to include "the natural and physical environment and the relationship of people with that environment." In this case, the relationship of people to their environment is affected by the HHS's action because xenotransplantation may create deadly new animal viruses. Due to this significant public health concern, HHS should have prepared an EIS.
  • Xenotransplantation also poses significant threats to the environment. The animals needed for xenotransplantation will increase the environmental problems caused by animal-based agriculture. U.S. farms already generate about 1.4 billion tons of animal manure a year, 130 times the quantity of U.S. human sewage, according to a 1997 report by the Senate Agriculture Committee entitled, Animal Waste Pollution in America: An Emerging National Problem. This untreated and largely unregulated manure, contaminated with bacteria, parasites, chemicals and heavy metals, is washed off farmland by rain and discharged into streams and rivers, killing fish, and making people who eventually drink it, bathe in it, and wash their clothes with it, sick.
  • In March 1999, a community in Sarpy County, Nebraska denied a permit to a xenotransplantation pig breeding/research facility because of environmental concerns alone.
  • Surveys find animal waste is degrading 1,785 bodies of water in 39 states. Pesticides, insecticides and antibiotics which are commonly used in agriculture may also contribute to soil and ground water contamination and consequently, harm human health. Pollution from factory farms impairs more miles of U.S. rivers than all other industry sources and municipal sewers combined. During the past two decades, the number of coastal waters that host major and recurring attacks by harmful microbes has doubled. Pigs and pig waste pose a particular danger because they contract and transmit many human diseases including meningitis, salmonella, chlamydia, giardia, cryptosporidiosis, brucella, worms and influenza. The hazards from hogs increases when they are packed closely together.
  • Hog farms pollute the air. In Minnesota, tests showed eight of 32 air samples taken near manure lagoons exceeded air quality standards for hydrogen sulfide. A study done at Duke University Medical Center revealed that those who lived downwind from hog factory farms suffered from a variety of illnesses including increased tension, depression, flu-like symptoms, fatigue, dizziness, blackouts, loss of appetite, and sleep disturbances.
  • HHS also failed to address the environmental and health impacts caused by the disposal of numerous remains of genetically modified animals. Conventional agricultural operations continuously wrestle with the problems of how to dispose of millions of tons of perishable animal tissue each year. Incineration, burial, and composting are all expensive, unhygienic, and environmentally problematic. In fact, in 1997, the Sierra Club filed a lawsuit against a hog farm, citing 50 violations of federal environmental laws, including the farm's illegal pits for disposing dead pigs. Disposing of transgenic pigs is a significant environmental and health concern, because if the bodies of source animals are disposed of improperly, their DNA could replicate, spread, and recombine, picking up genes from viruses in other species, and consequently, create new pathogens. Thus, disposing of genetically modified animals is an issue that should have been addressed in an EIS.
  • Can we justify raising more pigs for human use at a time when the Environmental Protection Agency is placing new restrictions on livestock pollution? Breeding animals for xenotransplantation would create a host of environmental problems, described above. Conventional farming and rendering operations have yet to solve these problems which continue to threaten public health across the US (see www.hogwatch.org).

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