There are many people out there waiting on transplant lists for organs to become available. Sadly, many of those people will never get the organ they need. In the United States alone, there are about 90,000 people who are waiting for a kidney right now. An average of twelve of them die every day. For years, researchers have been working on various ways to address this problem. Some advances have been made in areas like the 3D bioprinting of organs, or xenografting, in which a donor organ comes from a different species.
Now researchers have announced the successful transplantation of a kidney that was grown in a pig, into a human patient. Scientists can't simply transplant a pig's kidney into a person, because a molecule called alpha-gal that is expressed on pig kidney cells will trigger an immune reaction from the human body; the pig's organ would immediately be rejected.
To address that problem, scientists developed a genetically engineered pig that would not express the offending molecule. Once this organ was created, the researchers performed a test in which the kidney was attached to the blood vessels of a deceased person. This prof-of-concept process enabled the scientists to observe the function of the pig kidney over the course of two days. They saw that the organ was able to do the work of filtering blood and generating urine, and it did not stimulate the immune system to reject it.
The person that volunteered for this procedure wanted to donate their organs, but they were not suitable, which can happen for many reasons. But for the family, this was a way for some good to come of the situation.
This research success marks a major advance in the field, though the work has not yet been submitted to a journal for peer-review. Future work will also have to investigate how long this kind of donated organ remains healthy and functional; with any luck, it will be safe and effective in recipients for many years.
The company that produced the pig that grew the organ, Revivacor, has previously tested a pig heart in a baboon. In that model, the heart remained alive for 945 days.
If this new kidney is safe to use in humans and works for a long time, it could be a major breakthrough for the many people waiting for kidneys, and potentially one day soon, other organs too.