U.S. surgeons transplant a gene-edited pig kidney into a patient for the 1st time
NEW YORK —Surgeons in Boston have transplanted a kidney from a genetically engineered pig into an ailing 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.
Kidneys remove waste products and excess fluid from the blood. The new kidney began producing urine shortly after the surgery last weekend and the patient’s condition continues to improve, according to physicians 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 kidney disease.
A new source of kidneys “could solve an intractable problem in the field — the inadequate access of minority patients to kidney transplants,” said Dr. Winfred Williams, associate chief of the nephrology division at Mass General and the patient’s primary kidney doctor.
If kidneys from genetically modified animals can be transplanted on a large scale, dialysis “will become obsolete,” said Dr. Leonardo V. Riella, medical director for kidney transplantation at Mass General. The hospital’s parent organization, Mass General Brigham, developed the transplant program.
Over 800,000 Americans have kidney failure and require dialysis, a procedure that filters toxins from the blood. Over 100,000 are on a waiting list to receive a transplanted kidney from a living or dead human donor.
In addition, tens of millions of Americans have chronic kidney disease, which can lead to organ failure.
While dialysis keeps people alive, the gold-standard treatment is an organ transplant. Thousands of patients die annually while waiting for a kidney, however, because there is an acute shortage of organs. Just 25,000 kidney transplants are performed each year.
Xenotransplantation — the implantation of an animal’s organ into a human — has for decades been proposed as a potential solution that could make kidneys much more widely available. But the human immune system rejects foreign tissue, causing life-threatening complications, and experts note that long-term rejection can occur even when donors are well matched.
In recent years, scientific advances including gene editing and cloning have edged xenotransplants closer to reality, making it possible to modify animal genes to make the organs more compatible and less likely to be rejected by the immune system.
The kidney came from a pig engineered by the biotech company eGenesis, which removed three genes involved in potential rejection of the organ. In addition, seven human genes were inserted to enhance human compatibility. Pigs carry retroviruses that may 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 make urine. Shortly afterward, scientists at the University of Alabama at Birmingham announced they had performed a similar procedure with similar results.
Surgeons at the University of Maryland have twice transplanted hearts from genetically modified pigs into patients with heart disease. While the organs functioned and the first did not appear to be rejected, both of the patients, who had advanced disease, died shortly afterward.
The transplant patient in Boston, 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 over a decade.