January 2017 Pulse
The shortage of transplantable organs is a public health crisis globally. In the United States, for example, 120,000 people are on the waiting list. It is estimated that 35 percent of all deaths in the U.S. can be prevented by organ transplantation.
In Singapore, the average waiting time for a kidney transplant is still 9 to 10 years, despite changes in the law to enlarge the donor pool.
In an effort to solve this global shortage of transplantable organs U.S. research centres are conducting studies on chimeras, trying to grow human tissues in animal hosts, with the aim of creating kidneys, livers and hearts for transplant.
Scientists are proceeding with such studies despite the fact that the National Institute of Health has clearly stated that it will not support chimera research until greater clarity is achieved concerning its ethical, legal and social implications.
Chimeras are currently used in many different studies. For example, the potential of human pluripotent cells in vivo is analysed by microinjecting these cells in a mouse embryo. The aetiologies of metabolic diseases in the ageing population are studied by creating ‘humanised’ mice to which cells from the liver and pancreas of human donors have been introduced.
In Singapore, human and bovine genes are combined to create cytoplasmic hybrid embryos that are purportedly 99% human. These hybrid embryos are used in embryonic stem cell research.
The National Council of Churches in Singapore has made a robust response to this initiative (See http://nccs.org.sg/2010/12/04/human-animal-combinations-for-biomedical-research/).
There are serious ethical issues associated with research involving human-animal chimeras. They include the violation of human dignity, the question of the moral status of the chimeric creature, the risk of creating humanised animals, the violation of the order of nature, and the many uncertainties accompanying such research.
These concerns notwithstanding, the advances in cutting-edge technologies such as stem-cell biology and gene-edition have made the incredible advances in chimera research possible.
For example, scientists can change the DNA of a mammal through genetic engineering, making it incapable to forming a specific tissue. Human stem cells are then added to the animal in the hope that a particular tissue, for example a human kidney, can form in the host animal.
However, for a number of technical reasons scientists are still unable to create a viable human organ in an animal host at this point.
One of the most challenging obstacles to their success is what has been described as the xenogenic barrier. The host animal – for example, a pig – and the human organ that it is supposed to incubate are two different species, making the viability of the chimeric creature itself problematic.
Scientists working on human-animal chimeras have long theorised that the closer the species are to each other, the higher the chance the chimera has of surviving. So, if the human-bovine chimera is not viable, perhaps a primate can be used to host the human organ.
We must ask how far we are willing to go to create transplantable human organs to save lives. If primates prove to be equally unsuitable hosts, what’s next?
Taking the discussion to the extreme, will we consider using people in permanent vegetative state but who are otherwise in relatively stable condition as possible hosts? What about people who are suffering from senile dementia? Can they also be used to incubate organs for transplantation?
Many bioethicists see the importance of imagining a fictional dystopia to address the possible future scenarios presented by the trajectories of current medical and technological capabilities that would enable them to anticipate ethical and social issues that might arise.
This brings us to a fundamental question in bioethics, one that is sometimes unfortunately muted if not silenced by the thick rhetoric in support of the technological imperative and biomedical triumphalism.
The question is: Without in any way trivialising the suffering of people with organ failure, is it society’s duty to save their lives at all cost? Or are there larger moral considerations that should govern our actions?
Bioethicists – both Christian and secular alike – have argued that although saving the lives of people with organ failure is important, it should not be achieved at all cost. They believe that there are other more important moral and social considerations. That is why killing a healthy individual to procure his or her organs and the trading of human organs are both unethical and illegal and should never be countenanced.
With the unprecedented advancements in stem-cell research and gene-editing technology, we must carefully reflect on where the line should be drawn as we work towards enlarging the organ pool.
In the midst of the bio-tech hype we must remind ourselves that in our noblest attempts to ameliorate suffering and cure diseases, we must never allow ourselves to pursue strategies that would in the long run distort our moral sensibilities and dehumanise our society.