Pig kidney transplanted into living human for the first time

Surgeons have successfully transplanted a pig kidney into a 62-year-old man living with end-stage kidney disease. The recipient, Richard Slayman, is recovering well and is expected to be discharged from the hospital soon, mere days after the surgery.

Is this the first ever pig kidney transplant?

This is the first time a pig kidney has been transplanted into a living human, which makes it a significant milestone in the field of xenotransplantation, or the transfer of animal organs to humans.

“The success of this transplant is the culmination of efforts by thousands of scientists and physicians over several decades,” said Tatsuo Kawai at Massachusetts General Hospital in a statement. “Our hope is that this transplant approach will offer a lifeline to millions of patients worldwide who are suffering from kidney failure.”

Strictly speaking, however, this isn’t the first ever pig-to-human kidney transplant. The procedure has been performed five times in the past, all in people who were declared brain-dead and kept on life support. The most recent of these took place in July 2023 by Robert Montgomery at NYU Langone Health and his colleagues. That kidney functioned for more than a month without signs of rejection or infection.

When did the surgery take place?

Kawai and his colleagues performed the surgery on 16 March. The procedure lasted 4 hours, and the kidney began producing urine and the waste product creatinine soon after, according to reporting by The New York Times. Slayman has also been able to stop dialysis, a further indication of the kidney’s proper functioning.

Where did the pig kidney come from?

The organ was provided by the pharmaceutical company eGenesis, which breeds pigs that have been genetically engineered to carry certain human genes and to lack a particular set of pig genes that are harmful to humans. These genetic modifications reduce the likelihood of transplant rejection, when the immune system attacks the organ and causes it to fail. Slayman is also receiving a cocktail of immune-suppressing drugs to further lower this risk. So far, there is no sign of rejection and Slayman is able to walk on his own. His doctors hope to discharge him from the hospital soon.

What do we know about the recipient?

Slayman has type 2 diabetes, high blood pressure and kidney disease. He had previously received a human kidney from a donor in December 2018. However, the organ showed signs of failure approximately five years later. He started dialysis in May of last year, but experienced complications, requiring visits to the hospital every two weeks. This had a serious impact on his quality of life while he awaited a second transplant.

More than 100,000 people in the US are waiting for an organ transplant, of whom 17 die each day. The US Food and Drug Administration authorised the experimental transplant for Slayman due to a lack of other treatment options.

“I saw it not only as a way to help me, but a way to provide hope for the thousands of people who need a transplant to survive,” said Slayman in a statement.

Have there been xenotransplant procedures involving other organs?

Only two other people have undergone a xenotransplant, both of whom received a genetically modified pig heart. The first, a man named David Bennett, passed away two months later, potentially due to complications from a pig virus called porcine cytomegalovirus. As such, scientists genetically inactivated this and similar viruses in the pig that Slayman’s kidney came from.

The second recipient, a man named Lawrence Faucette, died from transplant rejection six weeks afterwards.