Surgeons transplant pig kidney into patient, medical milestone

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Boston surgeons transplanted a kidney from a genetically modified pig into a sick 62-year-old man, the first procedure of its kind. If successful, the breakthrough offers hope to hundreds of thousands of Americans whose kidneys have failed.

So far, the signs are promising. The new kidney began producing urine shortly after surgery last weekend and the patient’s condition continues to improve, according to doctors at Massachusetts General Hospital, known as Mass General. He is already walking the halls of the hospital and may be discharged soon.

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

A new source of kidneys “could solve an intractable problem in the field: minority patients’ inadequate access to kidney transplants,” said Dr. Winfred Williams, associate chief of Mass General’s division of nephrology and a primary care physician. of the patient.

If kidneys from genetically modified animals can be transplanted on a large scale, dialysis “will become obsolete,” said Dr. Leonardo V. Riella, 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 suffer from kidney failure and require dialysis, a procedure that filters toxins from the blood. More than 100,000 people are on the waiting list to receive a kidney transplant from a living or dead human donor.

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

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

Xenotransplantation (the implantation of an organ from an animal into a human) has been proposed for decades as a possible solution that could make kidneys much more available. 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 a good match.

In recent years, scientific advances, including gene editing and cloning, have brought xenotransplants closer to reality, making it possible to modify animal genes to make organs more compatible and less likely to be rejected by the immune system.

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

In September 2021, surgeons at NYU Langone Health in New York attached a kidney from a genetically modified pig to a brain-dead man 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.

Surgeons at the University of Maryland twice transplanted hearts from genetically modified pigs into patients with heart disease. Although the organs worked and the first did not appear to be rejected, both patients, who had advanced disease, died shortly after.

(Patients who accept these cutting-edge experimental treatments are often extremely sick and have few options available; they are often too sick to qualify for the waiting list for a valuable human organ or are ineligible for other reasons.)

The Boston transplant patient, Richard “Rick” Slayman, a state transportation department supervisor, had suffered from diabetes and hypertension for many years and had been under treatment at Mass General for more than a decade.

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

When Slayman resumed dialysis in 2023, he experienced severe vascular complications (his blood vessels clotting and failing) and required recurrent hospitalization, Dr. Williams said.

Slayman, who continued to work despite his health problems, faced a long wait for another human kidney and “became increasingly despondent,” Dr. Williams said. “He said, ‘I just can’t go on like this. I can’t keep doing this.’ “I started thinking about extraordinary measures we could take.”

“I would have had to wait five to six years to get a human kidney. He would not have been able to survive,” added Dr. Williams.

When Dr. Williams asked Mr. Slayman about receiving a pig kidney, Mr. Slayman had many questions but ultimately decided to continue.

“I saw it not only as a way to help myself, but also as a way to provide hope to thousands of people who need a transplant to survive,” he said in a statement provided by Mass General.

Mr. Slayman’s new kidney seems to be working so far and he has been able to stop dialysis. The pig’s new kidney produces urine as well as creatinine, a waste product.

Other measures are also improving daily, his doctors said. Doctors will continue to monitor Mr. Slayman for signs of organ rejection.

“He looks like himself. He is extraordinary,” said Dr. Williams.

The four-hour operation was performed by a team of surgeons, including Dr. Tatsuo Kawai, director of the Legorreta Center for Clinical Transplant Tolerance at Mass General, and Dr. Nahel Elías.

The procedure was performed under a Food and Drug Administration protocol known as the compassionate use provision, which is granted to patients with life-threatening illnesses who could benefit from an unapproved treatment. New medications were also used within the framework of the protocol to suppress the immune system and prevent organ rejection.

“He is remarkably brave in coming forward,” Dr. Williams said of Mr. Slayman. “I take my hat off to him. He is making a great contribution with this.”

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