Can a pig kidney keep you off dialysis while you wait?
Yes. A gene-edited pig kidney kept one man off dialysis for 271 days, and he later received a human kidney that worked immediately. Surgeons at Massachusetts General Hospital gave him the pig kidney in January 2025, in a first-in-human study of a pig kidney used as a bridge to a human transplant.
When both kidneys fail, there are only two options: dialysis, which means hours hooked to a machine several times a week, or a transplant. Far more people are waiting than there are human kidneys. This man had a long expected wait for a deceased donor kidney and no suitable living donor.
The pig kidney was not an ordinary pig kidney. It came from a pig whose genome had been edited in three ways. The sugar molecules on pig cells that the human immune system attacks first were deleted. Viruses built into the pig’s own DNA, called porcine endogenous retroviruses, were switched off. And seven human genes were added so the organ would look less foreign to a human body.
What the data show
The transplant took place on January 25, 2025, and the kidney started making urine immediately. It kept him off dialysis for 271 days.
It was not a smooth 271 days. A biopsy on day 14 showed rejection driven by T cells, a type of white blood cell, and that episode cleared with treatment. The kidney then worked steadily for about six months. At that point he developed a bacterial infection, one that did not come from the pig, and his anti-rejection drugs were reduced to help him fight it. After that, inflammation appeared in the kidney’s smallest blood vessels along with damage to the vessel lining. That progressed to thrombotic microangiopathy, which means tiny clots choking off those vessels. The kidney failed and was removed.
The part that matters most for the future came next. Eighty-two days after the pig kidney was taken out, he received a human kidney from a deceased donor in January 2026. It worked right away. Over 231 days of follow-up there was no sign that the pig kidney had left his immune system primed to attack a human organ. His anti-HLA antibodies, the antibodies that would make a future transplant fail, were unchanged. No pig pathogen transmission was detected.
Dr. Kumar’s Take
Two fears have hung over pig organ transplants for decades. One is that a pig virus crosses into a person and then into the population. The other is less discussed but more practical: that exposing someone to pig tissue revs up their immune system so badly that they can never receive a human organ afterward. That would mean a pig kidney is a one-way door, and no one would responsibly offer it to a patient still on the human waiting list.
This case says no to both, at least once. No pig pathogen was found, the antibodies that block human transplants did not budge, and the human kidney he received afterward worked from the first minute. That changes what a pig organ can be. It stops being a last resort for someone with no options left and becomes something you could use for a stretch of time and then hand back.
The failure is worth studying as much as the success. The kidney did not die from classic antibody rejection, and the crossmatch test that usually warns you stayed negative the whole way. The tissue was full of macrophages and natural killer cells with barely any T cells involved. Something other than the textbook rejection pathway damaged this organ, and the standard monitoring tests did not see it coming.
Important limitations
This is one patient. He is the first of a planned three-patient study run under a US Food and Drug Administration Expanded Access application, which is a pathway for giving an unapproved treatment to people with serious illness, not a controlled trial. There is no comparison group, so nothing here tells you how a pig kidney stacks up against staying on dialysis or waiting for a human organ.
The graft also failed. It lasted 271 days, not years, and its decline began with a common problem in transplant medicine: an infection that forced doctors to back off the drugs holding rejection in check. That trade-off does not disappear because the organ came from a pig.
Practical Takeaways
- If you or a family member is facing dialysis, pig kidney transplants are still experimental and available only through a small number of research programs at specialized centers, so a human transplant workup remains the path to pursue.
- Ask a nephrologist about living donor options early, since this man was offered a pig kidney specifically because he had no suitable living donor and a long expected wait.
- Understand that a pig kidney is being tested as a temporary bridge, not a permanent replacement, and this one functioned for 271 days before it had to be removed.
- Infections during transplant care matter more than most people realize, because treating them often means lowering the drugs that protect the transplanted organ.
Related Studies and Research
- An AI-designed universal coronavirus vaccine passes its first human test
- Finerenone slows kidney decline in people without diabetes
- Less sugar in a baby’s first 1,000 days meant far less cancer 50 years later
- Time-restricted eating helps keep weight off a year later
FAQs
How long did this pig kidney last?
It kept him off dialysis for 271 days before it failed and had to be removed. This was a first-in-human study, so 271 days is the number to hold onto, but it is still one organ in one person. Whether the next two patients in this three-patient study come close will say much more about whether the result holds up.
Why did the pig kidney have to be genetically edited at all?
The kidney used here, called EGEN-2784, carried three separate kinds of change. The major glycan xenoantigens were deleted, meaning the sugar molecules on pig cells that mark the organ as foreign to a human immune system were removed. Porcine endogenous retroviruses, which are viral sequences sitting inside the pig’s own genome, were inactivated to address the worry that a dormant animal virus could wake up in a human host. And seven human transgenes were inserted. On top of the edits, the recipient received costimulation blockade-based immunosuppression along with complement inhibition, two ways of holding back different arms of the immune response.
Does receiving a pig kidney hurt your chances of getting a human one later?
In this case it did not. His anti-HLA antibodies, the ones that decide which human donors he can safely accept, were unchanged after the pig kidney, and the human kidney he received 82 days after the pig organ was removed worked immediately with no evidence of sensitization across 231 days of follow-up. That is the single most useful finding here for anyone on a waiting list. It is also one patient, so it is a proof that this can happen, not a guarantee that it always will.
Bottom Line
A gene-edited pig kidney kept a man alive and off dialysis for 271 days, and when it failed and was removed, he went on to receive a human kidney that worked immediately with no sign his immune system had been turned against human organs. No pig pathogen crossed over. The organ did eventually fail through a blood vessel injury that standard rejection tests never flagged, and this is still a single patient in a three-person study. But the central question, whether a pig organ can serve as a temporary bridge and then be given up without burning the bridge to a human transplant, now has one clear answer.
