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• Posted June 5, 2024

Transplanted Pig Kidney Is Removed From Woman Who Received It

A woman who was the second person to ever receive a kidney from a genetically modified pig has had the transplanted organ removed due to complications linked to a heart pump she is using, her doctors said.

Lisa Pisano, 54, remains hospitalized and has been transferred back to kidney dialysis after having the transplanted organ removed.

The organ, transplanted 47 days earlier, had not been rejected by her body.

However, Pisano is battling both kidney failure and heart failure, and a heart pump that she needed to survive failed to provide adequate blood supply to the new kidney, doctors at NYU Langone Transplant Institute in New York City told the New York Times.

"Lisa is in stable condition, and her left ventricular assist device [heart pump] is still functioning,"said Dr. Robert Montgomery, who directs the Institute. "We are hoping to get Lisa back home to her family soon."

He told the Times that "Lisa is a pioneer and a hero in the effort to create a sustainable option for people waiting for an organ transplant."

They noted that Pisano is the first patient with a heart pump to undergo any kind of organ transplant. Patients with kidney failure are often not allowed to receive such devices because their risk of death is so high.

'A better life'

In April, when the pig kidney transplant occurred, New Jersey native Pisano was staring down the end of her days.

She had heart failure and end-stage kidney disease, but several chronic medical conditions had excluded her as a candidate for heart and kidney transplants.

"All I want is the opportunity to have a better life,"Pisano said in a news release issued to announce the transplant. "After I was ruled out for a human transplant, I learned I didn't have a lot of time left."

But Pisano got a new lease on life, thanks to a combined transplant of the mechanical heart pump and a gene-edited pig kidney.

It was the first time the two vastly different medical technologies have been performed on one patient, her surgeons said.

There are no documented instances of anyone with a mechanical heart pump receiving an organ transplant of any kind, they added.

It was also only the second known transplant of a gene-edited pig kidney into a living person, they said.

The first occurred in March, with doctors at Massachusetts General Hospital placing a genetically tweaked pig kidney into Rick Slayman, 62, of Weymouth, Mass.

"It is incredible to consider the scientific achievements that have led to our ability to save Lisa's life, and what we are endeavoring to do as a society for everyone in need of a lifesaving organ,"Montgomery said.

Unique approach

Nearly 104,000 people are on the waiting list for a transplant, including more than 89,000 waiting for a kidney, the doctors said in background notes.

About 808,000 people in the United States have end-stage kidney disease, but only about 27,000 received a transplant last year, they added.

Surgeons first implanted the heart pump into Pisano, and days later followed up by implanting the gene-edited pig kidney and the pig's thymus gland to help ward off rejection.

Without the heart pump, Pisano's life expectancy would have been measured in days or weeks, researchers said.

But Pisano was stuck in a Catch-22, as patients with chronic kidney disease typically aren't allowed to get a heart pump.

"Without the possibility of a kidney transplant, she would not have been eligible as a candidate for [a heart pump], due to the high mortality in patients on dialysis with heart pumps,"said Dr. Nader Moazami, chief of heart and lung transplantation at NYU Grossman School of Medicine.

"This unique approach is the first time in the world that [heart pump] surgery has been done on a dialysis patient with a subsequent plan to transplant a kidney,"Moazami added in an NYU Langone news release.

The pump was implanted on April 4, and the pig kidney transplant occurred on April 12.

'Solution to the organ shortage'

Pisano had high levels of harmful antibodies that would have attacked any transplanted human kidney, doctors noted. It likely would have taken years to find an appropriate human match.

But Montgomery found that an experimental gene-edited pig kidney developed by United Therapeutics Corp. was not only available, but also was a good match for Pisano.

The kidney was engineered to block a gene responsible for producing a sugar known as alpha-gal. Previous studies have shown that removing alpha-gal can prevent an antibody reaction that can trigger rejection of the pig kidney.

Pisano also received the donor pig's thymus gland, which is responsible for educating the immune system and will further lower the risk of rejection.

Other experimental gene-edited pig organs have included many different genetic alterations intended to ward off rejection, but Montgomery thinks simple could be better.

"By using pigs with a single genetic modification, we can better understand the role one key stable change in the genome can have in making xenotransplantation a viable alternative,"Montgomery said.

"Since these pigs can be bred and do not require cloning like more-complex gene edits, this is a sustainable, scalable solution to the organ shortage,"Montgomery added. "If we want to start saving more lives quickly, using fewer modifications and medications will be the answer."

More information

Harvard Medical School has more on the first gene-edited pig kidney transplant.

SOURCE: New York Times; NYU Langone Health, news release, April 24, 2024