Xenotransplantation Basics: No, it’s not a warrior princess
Imagine a world where we have farms of pigs and primates, purposely bred and used for human organs. Or consider a scenario much like Nalo Hopkinson’s novel, Brown Girl In The Ring, where xenotransplantation is the norm, and human-to-human organ donation is seen as barbaric, even cannibalistic.
Using animal organs and tissue in lieu of human ones? Yes readers, this is happening. Officially the procedure is called xenotransplantation, and its official FDA definition states:
Xenotransplantation is any procedure that involves the transplantation, implantation or infusion into a human recipient of either (a) live cells, tissues, or organs from a nonhuman animal source, or (b) human body fluids, cells, tissues or organs that have had ex vivo contact with live nonhuman animal cells, tissues or organs.
Though most cases of xenotransplantation are still in laboratory-testing phases (e.g. pig to non-human primate, rat to mouse, etc.), there are some cases of non-human animal to human xenotransplantation. These cases mostly being the use of pig heart valves to replace human ones, and using pig skin on burn patients.
Xenotransplantation expert and doctor David Cooper whom we’ve highlighted in TranplantInformers previously is a well known researcher in this field . He is working to genetically engineer pigs to have a greater defense against the human immune response, also known as organ rejection. Other new procedures to look for are using fetal pig stem cells for cell regrowth in humans, and potentially using primates as human organ sources.
The idea of xenotransplantation is not a new one, however recent technologies and the constant need for organs have made xenotransplantation a more realistic practice. As with any new technology, the ethical issues surrounding xenotransplantation are astounding, likely because there are so many factors in play. In addition to patients, doctors, hospitals, insurance companies and other potential stakeholders to consider, there are the animal donors. After a basic web search, Stanford’s website was the only one I found that dealt with how the pigs should be raised and where they should come from – including strict regulations with breeding lineages, proper documentation, and careful housing and diet. Some people question if we even should start raising animals for this alternative type of human consumption. And other institutions may deem funding xenotransplantation as too expensive, especially with other up-and-coming technologies like using a recipient’s healthy cells to regrow his or her own organs in a petri dish.
One of the more complicated issues that make larger institutions hesitant towards xenotransplantation is trying to figure out who is liable if an xenotransplantation recipient rejects the organ or suffers worse consequences. Would it be the pig the organ came from? Or the farm that raised the pig? Or perhaps the hospital that approved the procedure? Or maybe it could be an issue with the patients own body?
In an anticipatory fashion, it is important to be aware of this emergent technology and the attendant concerns, because perhaps in a not-so-distant future we may be further blurring the gap between species!
The abstract of Kuwaki, Tseng et al article on transplanting hearts from gene-knockout pigs into baboons. And their follow up article (abstract only) about the baboon’s survival approaching 6 months after operation.