Although xenotransplantation is still a long way off, clinical trials could begin early in the next decade, reports the Journal of Medical Ethics, with GM pig kidneys inserted into adult humans. With the 1984 Baby-Fae incident as an impetus, animal rights activists began protesting, attracting media attention and proving that some people considered it unethical and a violation of the animal`s own rights to use its organs to sustain the life of a sick person. [71] Treating animals as mere tools of slaughter at the request of human will would lead to a world they would not prefer. [71] Proponents of transplantation fought back, claiming that saving a human life justified the sacrifice of an animal. [71] Most animal rights activists have found the use of primate organs more objectionable than, say, pigs. [71] As Peter Singer et al. Many primates exhibit superior social structure, communication skills, and affection than mentally handicapped humans and human infants. [72] Nevertheless, animal suffering is highly unlikely to provide regulators with sufficient impetus to prevent xenotransplantation. [40] The XNA target epitope is a α-bound galactose unit, galactose-alpha-1,3-galactose (also known as the α-gal epitope), produced by the enzyme alpha-galactosyltransferase. [44] Most non-primates contain this enzyme, so this epitope is present on the epithelium of the organ and is perceived as a foreign antigen by primates lacking the enzyme galactosyltransferase. In xenotransplantation from pigs to primates, XNA recognizes porcine glycoproteins of the integrin family. [38] Xenotransplantation is any procedure involving the transplantation, implantation or infusion into a human recipient of (a) living cells, tissues or organs of non-human animal origin or (b) human body fluids, cells, tissues or organs that have had ex vivo contact with living animal cells, tissues or organs. The development of xenotransplantation is driven in part by the fact that the demand for human organs for clinical transplantation far exceeds supply.
Autonomy and informed consent are important when it comes to the future use of xenotransplantation. A patient undergoing xenotransplantation should be fully aware of the procedure and not have any external force that affects his choice. [73] The patient must understand the risks and benefits of such a transplant. However, it has been suggested that friends and family members should also give consent, as the effects of transplantation are high and the potential for diseases and viruses shifts from transplantation to humans. Close contacts are at risk of such infections. Monitoring of close relationships may also be necessary to ensure that xenozoonosis is not present. The question then becomes: is the patient`s autonomy limited because of the willingness or unwillingness of friends and family to give consent, and are confidentiality principles violated? So far, there have been a few successful xenotransplantation attempts, but no human organ projects are approved by the Federal and Drug Administration. Let`s look at some developments that have been made. Earlier in this article, we looked at how organ rejection after xenotransplantation is a major obstacle for surgeons, which, along with issues such as ethics, delays the development of xenotransplantation. As a study published in Animal Frontiers shows, progress has already been made in transplanting corneas, kidneys, hearts and neuronal cells.
However, there is no doubt that the use of animal organs for human welfare comes with many concerns, such as the ethics associated with it. What is your position on this subject? Are you passionate about xenotransplantation or is it something you don`t think should happen? Immune rejection remains the biggest challenge for xenotransplantation. The problem even exists with interhuman transplants (known as allotransplantation), but it is more serious with transplants between different types. Almost all mammalian cells have markers that allow the immune system to recognize them as non-foreign. The more different the genetic code between the donor organ and the recipient, the greater the difference between a “self” marker and a “foreign” marker. Some companies are currently developing transgenic animals, such as pigs, that produce human markers. For xenotransplantation, the one-year survival rate has risen from 67% to 85% in recent decades, according to the Centers for Disease Control and Prevention. Just as the α1.3G epitope is a major problem in xenotransplantation, dysregulated coagulation is also a cause for concern.