114,000 people in the US alone are desperately waiting for an organ transplant. Scientists are now turning to pigs as possible organ donors.
The year was 1979. Britain’s first heart transplant was just successfully completed by Sir Terence English — a renowned UK surgeon.
Fast forward 40 years, English’s protege during his 1979 surgery team is getting ready for the first pig-to-human kidney transplant in the world.
If successful, it will open doors to procedures involving pig-to-human transplants of more complex organs like the heart and lungs.
English: “If the result of (the surgery) is satisfactory with porcine kidneys to humans, then it is likely that hearts would be used with good effects in humans within a few years. If it works with a kidney, it will work with a heart.”
With 20 people dying every day while waiting on an organ transplant in the US and almost 114,000 in need of an organ, this new procedure could be life-saving and drastically reduce or even eliminate the waiting list for organ transplants.
Animal Organ Transplantation: From Idea to Reality
The process of using non-human donors for human organ transplants is called xenotransplantation (the prefix xeno- means ‘other’ or ‘foreign’).
The idea of xenotransplants has been around for quite some time. Starting in the 1960s, there has been some recorded attempts at trying to transplant animal organs for human use — though none of them had long-surviving patients.
The recent scientific breakthrough that made scientists rethink the possibility of using animals organs had to do with two genes in the DNA in pigs.
Professor Christopher McGregor, who was the senior registrar for Sir Terence 40 years ago, had recently used modern state-of-the-art gene-editing techniques to disable two genes in the pig’s organ’s DNA. The two changes then allowed the organs from the pigs to, theoretically, function properly in humans.
Terence English and his team aren’t alone in his quest for efficient xenotransplantation. Other researchers, such as Harvard geneticist George Church and the co-founder of eGenesis (a biotech company), has used various gene-editing techniques like CRISPR to adapt pig organs for human use.
Would a pig organ actually work in a human?
Before we answer that question, we should address why are biologists specifically using a pig in the first place.
Pig physiology and organ size are very similar to humans, allowing their organs to have a much easier time to adapt to a human body compared to organs derived from other animals like cows.
Previously, researchers from the US National Institutes of Health (US NIH) had succeeded in transplanting a pig heart into a baboon and kept the baboon alive for more than two years.
In another separate study in Germany, researchers were able to give multiple baboons heart transplants from pigs, and all of them survived for more than six months.
Those numbers may seem low at first glance, but keep in mind that the average life expectancy of a baboon is also much lower than that of a human’s.
From these studies, we can see that the transplants from pigs could both theoretically and practically work — though not very effectively.
If researchers want to meet Sir Terence’s expectation of pig-to-human heart transplants in three years, they are going to have a lot of work to do.
The Ethical Issues Involving Xenotransplantation
The next thing that comes to mind after questioning the logistics of this procedure is its ethics.
Given the spike in animal rights activists in recent years and their lobbying to prevent animal suffering, the introduction of pig-to-human transplants could face severe backlash.
Sir Terence took note to that fact and commented:
“There will be animal rights people who will say it’s entirely wrong, but if you can save a life isn’t that maybe a bit better?”
So the question may come down to whether a person’s life matters more than a pig’s life.
The obvious answer to that question at first may seem to be a definitive yes. However, approval from world governments for this procedure will necessitate much more debate and back-and-forth than just saying yes.
There also may be other unforeseen technical or ethical issues that will have to be addressed as scientists try to implement the procedure.
Anyhow, given how much demand there is for organs and how many are suffering from the lack of supply, large-scale xenotransplantation may be the solution that we have been seeking for decades.
It is truly an exciting time for not only the field of medicine but also for all us as we witness novel procedures like this one that help patients around the world live a better life and address the problems modern science faces.