'Curiosity without compassion is inhuman; compassion without curiosity is ineffective' Victor Wiesskopf [1]

In early January, two companies announced dramatic advances in genetic engineering. The advance was the successful cloning of animals lacking the gene causing organ rejection in humans.[2] This development brings us one step closer to xenotransplantation, the ability to use animals as organ donors for humans. In the light of these advances, we need to be aware of the potential pitfalls of implementing xenotransplantation in our fallen world. Like Wiesskopf, the pioneer of nuclear physics, we strive for a more balanced philosophy in our scientific age.

Immerge BioTherapeutics, working with a team from the University of Missouri-Columbia, were first to announce the advance. They used 'knock-out' gene technology to clone pigs lacking the gene for Alpha-1,3- galactosyltransferase. Shortly after, PPL Therapeutics, an Edinburgh based firm, announced that five pigs lacking the same gene were born on Christmas Day. Alpha-1,3-galactosyltransferase makes an enzyme that adds sugar molecules to the surface of cells. Human antibodies normally attach to these molecules on the surface of the pig organ cells and normally cause an aggressive immune response.[3] Therefore this new development is a very big step towards making xenotransplantation a reality.

Most cultures, including Christians, are generally in favour of transplantation. Certainly, the donation of blood, the first transplant procedure to become a routine part of modern medicine, has been regarded as a good and loving act.[4] Clearly, there is no obvious biblical basis for the Christian viewpoint, since transplantation would simply not have been an issue when it was written. However, the attitude of self sacrificial love, exemplified perfectly in Jesus,[5] would seem to suggest that human organ donation and transplantation would be in line with biblical ideals. However, the 'yuk factor' and concerns about safety raise further questions about the use of animal organs in humans.

The secular scenario

The secular case for xenotransplantation is strong. Firstly, demand far outstrips potential donor supply. Consequently, most patients die before a suitable donor is found.[6,7] No initiatives, including ethically dubious opt out policies (presuming consent when objection has not been recorded), have been able to provide for the growing number of potential recipients. Secondly, reliable and safe artificial organs are not likely to be available in the short term, despite recent advances. Thirdly, in a meat eating society, it is hard to argue against the use of animals for transplantation.[8] Pigs are the most promising source of organ transplants as they are physiologically similar to humans, and unlike primates, are in plentiful supply.[9]

There are, however, technical concerns. Infectious diseases are common after organ transplantation, due to the immunosuppressive agents used to prevent graft rejection. This risk may be greater in xenograft recipients because of the possible need for greater levels of immune suppression and the role of novel pathogens from animals. Many of these organisms might be excluded from closed herds of donor swine by careful breeding. However there are known to be endogenous retroviruses integrated into the porcine genome. This means they reside in every cell of every pig, and therefore are less susceptible to exclusion.[10] The donated organ may also be susceptible to human viruses in a way we cannot predict.[11] Another major stumbling block has been the aggressive response of the human body's immune system to the foreign tissue when antibodies attach to sugar molecules on the surface of the pig organ cells.[12] This last hurdle now seems to have been overcome.

Examining the dangers

The Christian Medical Fellowship has been prepared for these developments for a long time. In 1995, CMF submitted an official statement to the Nuffield Council of Bioethics on xenografts.[13] The council was set up that year, consisting of doctors, educationalists, journalists, lawyers, philosophers, scientists and theologians, seeking to examine the issues surrounding the use of animal cells, tissues and organs in the treatment of human disease. The Nuffield Foundation, responsible for setting it up, is a well-endowed independent charity, committed to advancing education and social welfare. The CMF statement explained that despite common biological origins [14] only human beings have unique significance, being made 'in the image of God.'[15] Humans were commanded to 'rule over' the animal world,[16] which implies both authority and responsibility, without exploitation.

PPL's research director Alan Colman, said recently that 'this [development in xenotransplantation] has the potential to revolutionise the transplant industry.'[17] Comparison with the meat industry illustrates that while the benefit is clear, the potential for abuse is huge. PPL analysts put the value of the market for solid organs at $5bn (£3.6bn; €5.7bn), and cellular therapies for diabetes, Parkinson's disease, and Alzheimer's disease could be worth another $6bn.[17]

The obvious commercial pressures involved could easily lead to animal exploitation, and the killing of excessive numbers. Financial considerations might also lead to undue pressure being put on prospective organ recipients. CMF also outlined the need for other safeguards. There may be unforeseen hazards associated with the creation of 'super animals' with altered genomes. Of even more concern, technical advances might make it possible to produce an animal/ human hybrid. Leviticus 19:19 specifically forbids the mating of different animals. While applying OT law to modern times is often problematic, the passage emphasises the importance of the distinctiveness of the people of God.[18] They should act in a way that distinguishes them because they are fundamentally distinct. God's creational ordinance makes clear that all mankind is distinct from the animal kingdom,[19] and we should not endanger this unique position lightly.

A measured response

We need to be aware of the issues and be biblical in our intellectual response to them. In this way, the Christian doctor can be distinct in carefully influencing and challenging the debate. The primary concerns are the safety and potential for exploitation of both humans and animals. Despite rapid developments, there is much we still do not know about animal transplantation. There is bound to be frustration as patients die on transplant lists, but we must resist impatience about theoretical concerns. Beneath the spin, more research is needed before any large scale trials in humans can occur, and the profession needs to guard against industry attempts to push unbalanced points of view. We must strive to be clear in our response to technological advances. Christians do not want to stop all experimental work, renounce the knowledge acquired from it, or reject the real benefits inherent in new techniques. We should, however, be wary of technism, the assumption that the technological answer is the only answer.[20] Our stewardship over the animal kingdom is not optional. Companies should not be allowed to breed animals in poor conditions in excessive, uncontrolled numbers. Lastly, thinking about xenotransplantation should challenge our views on transplantation in general. Perhaps, if we have not done so already, this is a time to make conscious decisions about organ donation ourselves.