Xenotransplantation: Revolutionizing Organ Transplants

By Calin-Rares Manta

Organ transplants are a common medical practice that has been around since the late 19th century, only becoming accepted as medical technology improved and success rates increased in the late 20th century. Despite this, a persistent issue of the practice has been the shortage of suitable donors, which has unfortunately left many patients waiting for their transplants, in some cases even passing away before receiving them.

As medical advancements progress and the number of individuals in need of transplants grows, xenotransplantation could emerge as the go-to solution. In 2022, the FDA defined xenotransplantation as “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”.

Why xenotransplantation?

Xenotransplantation has several potential advantages over allotransplantation (human to human). The most important one is its capacity to offer a virtually unlimited source of organs, allowing for both advance planning and intentionally timed harvesting of an organ for immediate transplantation. Also, the risk of many infections can be reduced by allowing lifelong control of exposure of the source animals to potential infectious and extensive prescreening prior to organ harvest.

This procedure isn’t limited only to already existing animals, but extends to animals that have been themselves infused with human cells, growing human-compatible organs naturally, which could allow for even more controlled and scrutinized developments of organs, tissue and cells. Such expansion is likely to lead to the creation of organs that are far less likely to develop any sort of ailments or disorders.

Furthermore, through bioprinting, it is possible to “trick” animal cells to grow various human body parts, even as complicated and precisely shaped as the ear (as seen in the photo below), which can then be surgically transferred to the human patient.

Ethical concerns

The main ethical concern regarding xenotransplantation is animal welfare. As discussed earlier, its procedures may involve invasive techniques such as surgical implantation of human cells or organs into animals, genetic manipulation or organ extraction. These can cause pain, discomfort or distress to the animals involved. Moreover, research may require breeding animals specifically for use in experiments, which raises questions regarding the quality of life the animals are subjected to. While proponents may argue that it is necessary for advancing medical knowledge and potentially saving human lives, critics may argue that breeding animals for instrumental purposes undermines their intrinsic value and right to live free from unnecessary harm.

It is also worth considering that due to the potential flawlessness of a xenotransplanted organ, specifically the kind which was grown in a scientific environment to be as healthy for as long as possible, people may feel compelled to get organ transplants they don’t need in order to prevent future complications. This could become even more of a concern, as current research estimates that since some animal species are refractory to infection by certain viruses that persistently infect humans, recipients of xenotransplanted organs could have a therapeutic advantage.

Additionally, there are social and religious concerns regarding the practice which must be taken into account. Given the current research tendency to use porcine specimens for growing organs or transferring cells, it may one day pose a significant problem for specific patients, as in some cultures and religions such contact is strictly forbidden due to dietary laws or beliefs.

Current challenges

Xenotransplantation trials pose significant challenges due to the potential for transmitting infections and untreatable diseases from animals to humans, which poses a risk not only to research participants, but also to those with whom they come into contact. Concerns include immunologic problems (particularly the risks of hyperacute rejection) and the risk of xenogeneic infections (for example, in case of porcine-human xenotransplantation, concerns would arise regarding the existing human cellular receptors for porcine endogenous retrovirus (PERV), which infects certain human-derived cell lines in vitro).

Right now, the major concern with xenotransplantation is to avoid the emergence of infections that may cause a threat to public health. This unfortunately hinders any and all progress that can be made with clinical tests, making the prospect of one day being able to have an organ transplant from genetically modified animals or animal tissue appear distant and uncertain.

Conclusive thoughts

At first glance, the concept of xenotransplantation makes perfect sense, considering all the technological and medical advancements in recent times. It is even more reasonable to believe it’s the solution to the problem of organ supply shortages the medical industry is currently facing, as well as a way for mankind to have permanent access to substitute body parts and cells, which can make further research even easier. Unfortunately, the complexity of the human body, as well as the countless differences between the cells and tissue that animals harbor and the ones we possess makes this medical practice seem unfeasible for the time being.

Bibliography

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Animal Planet. (2008, November 19). Mouse ears. YouTube. https://www.youtube.com/watch?v=PEc7QXAjsL4

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Wikimedia Foundation. (2024, April 24). Xenotransplantation. Wikipedia. https://en.wikipedia.org/w/index.php?title=Xenotransplantation&oldid=1220577703#History