A medical milestone: Surgeons transplant a pig kidney into a patient

Surgeons in Boston transplanted a genetically modified pig kidney into a sick 62-year-old man, the first operation of its kind. If successful, this breakthrough provides hope to hundreds of thousands of Americans who have suffered kidney failure.

At the moment, the signs are promising.

The kidneys remove waste products and excess fluid from the blood. According to doctors at Massachusetts General Hospital, known as Mass General, the new kidney began producing urine shortly after last weekend’s operation and the patient’s condition continues to improve; He is already walking in the hospital corridors and may soon be discharged.

The patient is a black man, and the procedure holds special significance for black patients, who suffer higher rates of end-stage renal disease.

A new source of kidneys “could solve a difficult problem in the field: inadequate access to kidney transplants for minority patients,” said Winfred Williams, MD, associate chief of the department of nephrology and a top physician at Mass General.

If kidneys from genetically modified animals could be transplanted on a large scale, dialysis “would become obsolete,” said Leonardo V. Rilla, medical director of kidney transplantation at Mass General. The hospital’s parent organization, Mass General Brigham, developed the transplant program.

More than 800,000 Americans have kidney failure and require dialysis, a process that filters toxins from the blood. More than 100,000 people are on the waiting list to receive a transplanted kidney from a living or deceased human donor. End-stage kidney disease is three times more common in black Americans than white Americans.

Additionally, millions of Americans suffer from chronic kidney disease, which can lead to organ failure.

Although dialysis keeps people alive, the standard of care is organ transplantation. However, due to severe shortage of organs, thousands of patients die every year while waiting for a kidney. Only 25,000 kidney transplants are performed each year.

Xenotransplantation – transplanting an animal’s organ into a human – has been proposed for decades as a potential solution that could make kidneys more accessible. But the human immune system rejects the foreign tissue, leading to life-threatening complications, and experts note that long-term rejection can occur even when donors are matched.

In recent years, scientific advances such as gene editing and cloning have brought xenotransplants closer to reality, allowing animals’ genes to be modified so that organs are more compatible and less likely to be rejected by the immune system.

The kidney came from a pig modified by biotechnology company Egenesis, which had eliminated three genes involved in potential rejection of the organ. Additionally, seven human genes were inserted to improve human compatibility. Pigs carry retroviruses that can infect humans, and the company has also inactivated the pathogens.

In September 2021, surgeons at NYU Langone Health in New York implanted a genetically modified pig kidney into a brain-dead person and watched as it began to function and produce urine. Shortly afterward, scientists at the University of Alabama at Birmingham announced that they had performed a similar procedure with similar results.

On two occasions, surgeons at the University of Maryland transplanted hearts from genetically modified pigs into patients suffering from heart disease. Although the organs worked and the first was not rejected, both patients, who suffered from advanced disease, died shortly afterward.

(Patients who consent to these cutting-edge experimental treatments are often extremely ill and have very few options. They are often too sick to get on the waiting list for a precious human organ, or for other reasons Are disqualified from.)

Boston transplant patient Richard “Rick” Slayman, a supervisor with the state Department of Transportation, has suffered from diabetes and high blood pressure for several years, and was being treated at Mass General for more than a decade.

After kidney failure, Slayman was on dialysis for seven years; He eventually received a human kidney in 2018. But the donated organ failed within five years and he developed other complications, including congestive heart failure, Williams said.

Slayman’s new kidney appears to be working so far and he is able to stop dialysis. It already produces urine and filters out creatinine, a waste product.

According to his doctors, other indicators are also improving day by day. Doctors will continue to monitor Slayman for signs of organ rejection.

“He seems to be in normal health and spirits. It’s extraordinary,” Williams said.

The operation was not without criticism. Xenotransplants raise the possibility of even greater exploitation of animals and could introduce new pathogens into human populations, said Cathy Guillermo, senior vice president of People for the Ethical Treatment of Animals.

The intervention was conducted under a Food and Drug Administration protocol known as the compassionate use provision, which is given to patients with life-threatening illnesses who could benefit from an unapproved treatment. Newer drugs were also used to suppress the immune system and prevent organ rejection.

“The patient is very brave to volunteer,” Williams said of Slayman. “Hello. He’s making a huge contribution to this.”

In a photo provided by Massachusetts General Hospital, surgeons perform the world’s first transplant of a genetically modified pig kidney into a living human at Massachusetts General Hospital in Boston on March 16, 2024. (Massachusetts General Hospital via The New York Times)