Health
oi-Swastika Sruti
For the first time ever, a genetically engineered pig kidney kept a 66-year-old patient suffering from end-stage kidney disease off dialysis for nine months before he could receive a new kidney from a human donor.
In an advance for xenotransplantation, a gene-edited pig kidney at Massachusetts General Hospital served as a nine-month bridge for a 66-year-old patient awaiting a human transplant, functioning without antibody rejection or detected pig viruses.
This case, which is now being published in the journal The Lancet, is being considered a significant move towards making progress in xenotransplantation, which involves using animal organs to transplant into humans.
It is noteworthy about this case that the kidney from a pig was not supposed to act as a permanent organ replacement. It served as a “bridge” organ until the time a human kidney was available.
Pig Kidney Served as a Temporary Bridge
The operation took place at Massachusetts General Hospital in Boston using a gene-altered kidney derived from a Yucatan miniature pig.
The man suffered from end-stage kidney disease associated with type 2 diabetes and had a very slim possibility of having a human organ in the next five years. According to the scientists, his probability of obtaining a human organ was about 9%, whereas his probability of dying or being delisted from the waiting list exceeded 40%.
Thus, the transplantation of the genetically engineered organ could become an opportunity for him to survive and stay fit to get a human kidney later on.
The Genetically Engineered Kidney Started Working Immediately
The pig kidney started working right away after being transplanted in January 2025.
The level of creatinine, which helps to estimate the function of kidneys, immediately dropped. First of all, he did not need dialysis anymore.
But this procedure was not devoid of problems.
The problem with T-cell-mediated rejection appeared on the eighth day. They increased the dose of immunosuppression, and the process stopped.
Kidney provided useful function during several months.
Why Was the Pig Kidney Genetically Modified?
One of the biggest challenges in animal-to-human transplantation is the human immune system. The body recognises animal organs as foreign and can attack them rapidly. To reduce this risk, the kidney used in this case was extensively gene-edited.
The modifications included:
Removing major glycan xenoantigens – sugar molecules on pig cells that can trigger a strong human immune response.
Inactivating porcine endogenous retroviruses (PERVs) – viral genetic sequences naturally present in pig DNA that could pose a potential safety concern during transplantation.
Adding seven human transgenes – human genes intended to make the pig organ more compatible with the human body.
The patient also received powerful immunosuppressive medicines to reduce the risk of rejection.
Kidney Eventually Failed After Around Nine Months
While the pig kidney functioned for several months, it eventually started showing signs of deterioration. Damage to the blood vessels of the kidney was noticed six months after the procedure.
Eventually, this led to the failure of the organ.
It is reported that the transplantation of the kidney had to be withdrawn nine months after the surgery. In this case, it has been seen that the late failure was because of microvascular injury and thrombotic microangiopathy and not the usual rejection because of antibodies as expected in transplantation procedures.
Interestingly, the patient did not produce any antibodies against the pig kidney.
Human Kidney Transplant Was Successful
The case became even more significant after the pig kidney was removed.
Following several months back on dialysis, the patient received a kidney from a deceased human donor.
The human kidney functioned well during six months of follow-up. Researchers also found no new antibodies against human tissue.
This is important because one concern surrounding xenotransplantation is whether exposure to an animal organ could sensitise the patient’s immune system and make a later human transplant more difficult.
In this case, that did not appear to happen.
No Pig Viruses Were Detected
Safety is another major concern with xenotransplantation.
Because pigs can carry viruses and other pathogens, researchers closely monitored the patient for signs of infection.
According to the study, no pig viruses or other pig pathogens were detected at any point.
The finding provides some reassurance about the safety of using carefully screened and genetically modified pig organs, although researchers stressed that much more monitoring and research will be needed.
Why Xenotransplantation Could Help the Organ Shortage
Kidney transplantation is generally considered the preferred treatment for many people with end-stage kidney disease because it can provide better survival and quality of life than long-term dialysis.
The problem is that there are far fewer donor kidneys than patients waiting for them.
A genetically modified pig kidney could potentially change that situation because pigs can be bred and organs can be prepared under controlled conditions.
Instead of waiting years for a human donor, patients could potentially receive a pig kidney when they urgently need one.
The latest study introduces another possibility: using a pig kidney temporarily while a patient waits for a human organ.
Despite the promising result, the researchers have stressed that this is only a single-patient case.
There was no comparison group, and the treatment involved careful patient selection and intensive specialist care. Such resources may not be available in every hospital.
