The Story: In a medical first, surgeons transplanted a genetically modified pig heart into a human patient. Is such animal-to-human transplantation ethical?
The Background: In a first-of-its-kind surgery, a 57-year-old man with terminal heart disease received a successful transplant of a genetically modified pig heart. According to the team at the University of Maryland who conducted the surgery, the procedure was the only currently available option for the patient.
This organ transplant demonstrated for the first time that a genetically modified animal heart can function like a human heart without immediate rejection by the body, says the University of Maryland Medical Center (UMMC). The U.S. Food and Drug Administration granted emergency authorization for the surgery on New Year’s Eve through its expanded access (compassionate use) provision
Animal-to-human organ transplants were first attempted in the 1980s. In a famous case, Stephanie Fae Beauclair (known as Baby Fae) was born with a fatal heart condition and received a baboon heart transplant. She died within a month of the procedure due to the immune system’s rejection of the foreign heart, and similar transplant attempts were abandoned.
Medical researchers hope the use of pig organs will prove to be more successful. For the transplant at UMMC, four genes were “knocked out” of the pig organ to make it more compatible for use in a human. Six human genes responsible for immune acceptance of the pig heart were also inserted into the pig genome.
“This was a breakthrough surgery and brings us one step closer to solving the organ shortage crisis. There are simply not enough donor human hearts available to meet the long list of potential recipients,” said Bartley P. Griffith, MD, who surgically transplanted the pig heart into the patient. “We are proceeding cautiously, but we are also optimistic that this first-in-the-world surgery will provide an important new option for patients in the future.”
More than 100,000 Americans are currently waiting for an organ transplant, and 17 die each day waiting for a transplant, according to the federal government.
What It Means: Is it ethical to transplant animal organs into humans?
Most Christians have never had to consider the ethics of xenotransplantation, the transplantation of an organ or tissues from one species to another. But because of technological advances in biomedicine, that may soon change.
The reality is that such cross-species transplantation has been occurring—or at least attempted— for almost 300 years.
Cross-species transplantation has been occurring—or at least attempted— for almost 300 years.
In 1167 the French doctor Jean-Baptiste Denis, court physician to King Louis XIV, tried to infuse the blood from a lamb into a human (he believed the blood of a lamb, the symbol of the blood of Christ, would be a purer form of animal blood). In 1838 the first corneal transplant from an animal (a pig) was performed on a patient—65 years before the first human-to-human corneal transplant. Also, in the 19th century skin grafts became relatively popular between various animal species (sheep, rabbits, dogs, cats, rats, chickens, and pigeons) and humans. More recently, pig heart valves have been used successfully for replacing valves in humans.
Just because something has been done for centuries, of course, doesn’t mean it’s morally legitimate. But the reason it’s been done without much public outcry is that many Christian bioethicists (as well as Jewish and Muslim bioethicists) don’t consider such transplants to be unethical or going beyond proper natural limits. A procedure that does goes beyond such limits is the creation of animal-human chimeras. Chimeras are animals composed of cells that originate from two or more different species. To create an animal-human chimera, scientists introduce cells from one species into the developing embryo or fetus of another.
A distinction is often made by Christian bioethicists between the different uses of animal parts. For example, in 2005, Dr. Ben Carson, who at the time was director of pediatric neurosurgery at the Johns Hopkins Medical Institutions and a member of the President’s Council on Bioethics, said in a hearing on human-animal chimeras:
I think it’s very important as a council that we make sure that we distinguish between using human or animal parts across species, such as insulin, heart valves, things of that nature, and mixing the genetic material that has proliferative capacity. I mean, there’s a huge difference between those two things. We need to make sure that the public understands that we are distinguishing between those two things.
What distinguishes the two is that in chimeras, the mixture of animal-human parts becomes entangled during the developmental stage in a way that crosses a moral boundary. For example, the human cells could end up in gonadal tissue and form human gametes (eggs or sperm) within the animal’s body. The same concern for interspecies mixing is not true for the use of animal organs within an individual human. (A more worrying concern is the possibility of a virus mutating across species and creating a plague-like epidemic.)
In Genesis, God made clothes for Adam and Eve from animals (Gen. 3:21) and later gave animals for food (Gen. 9:3). Xenotransplantation could arguably be considered an extension of this legitimate use of animals for man’s survival needs.
While we need to continually be cautious about abusing our roles as stewards of the animal kingdom and avoid crossing obvious interspecies barriers, we should also give thanks to God for the lives that may be saved by such transplants.