Surgeons in Boston transplanted a kidney from a genetically engineered pig into a 62-year-old man in a first-of-its-kind procedure. If successful, the discovery would offer hope to hundreds of thousands of Americans with kidney failure.
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 operation last weekend, and the patient’s condition continues to improve, according to doctors at Massachusetts General Hospital, also known as Mass General. He is already walking the halls of the hospital and may be discharged soon.
The patient is black, and the procedure may have special meaning for black patients, who have a high rate of end-stage renal disease.
The new kidney source “could solve an intractable problem in the field — the underserved minority of patients receiving kidney transplants,” said Dr. Winfred Williams, associate chief of the nephrology department at Mass General and the patient’s primary nephrologist.
If kidneys from genetically modified animals can be widely transplanted, dialysis will be “obsolete,” said Dr. Leonardo V. The hospital’s parent organization, Mass General Brigham, developed the transplant program.
More than 800,000 Americans have kidney disease and need dialysis, a process 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 deceased donor.
In addition, tens of millions of Americans have chronic kidney disease, which can lead to organ failure.
While dialysis can keep people alive, the gold standard treatment is organ transplantation. Thousands of patients die every year while waiting for a kidney, but there is a huge shortage of organs. Only 25,000 kidney transplants are performed each year.
Xenotransplantation – transplanting an animal’s organ into a human – has been touted for decades as a potential solution to the widespread supply of kidneys. But the human immune system rejects foreign tissue, causing life-threatening complications, and experts say long-term rejection can occur even when donors are well-matched.
In recent years, scientific advances including gene editing and cloning have brought xenotransplants closer to reality, modifying an animal’s genes to make organs more suitable and less likely to be rejected by the immune system.
The kidney came from a pig made by the biotech company Igenesis, which removed three genes that can cause organ rejection. In addition, seven human genes have been introduced to improve human compatibility. Pigs carry retroviruses that can infect humans, and the company has also activated the pathogen.
In September 2021, surgeons at New Langone Health in New York attached a kidney to a genetically modified pig with a brain-dead human and watched it function and urinate. Not long ago, 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 have twice transplanted hearts from genetically modified pigs into heart patients. While the organs were functioning and the first one did not seem to be rejected, both patients, with advanced disease, died soon after.
(Patients who agree to these excellent experimental treatments are often very sick and have few options; they are often too sick to be on the waiting list for an expensive human organ or are ineligible for other reasons.)
“Rick Slyman, a state Department of Transportation supervisor, suffered from diabetes and high blood pressure for many years,” said Boston transplant patient Richard.
After his kidneys failed, Mr. Slaman was on dialysis for seven years and finally received a human kidney in 2018, but the donated organ failed within five years and had other complications, Dr. Williams said.
Mr. Slaman When he resumed dialysis in 2023, he developed serious vascular problems — the arteries were becoming stiff and tired — and required frequent hospitalizations, Dr. Williams said.
Mr. Sleiman, who continued to work despite his health problems, had been waiting for another human kidney for a long time, and “desperation was setting in,” Dr. Williams said. “He said, ‘I can’t go on like this. I can’t keep doing this.’ I began to think of unusual steps we could take.
“He had to wait five to six years for a human kidney. He would not have survived,” added Dr. Williams.
When Dr. Williams asked Mr. Slaiman about getting a pig kidney, Mr. Slaiman had many questions, but ultimately decided to go ahead.
“I saw it as a way to not only help me, but to give hope to the thousands of people who need a transplant to survive,” he said in a statement.
Mr. Slaman’s new kidney appears to be working so far and he has been able to stop dialysis. The new pig kidney is making urine and filtering out the waste product creatinine.
Other measures are also being improved every day, the doctors said. Doctors continue to monitor Mr. Slimane for signs of organ rejection.
“It looks like its own. It’s amazing,” said Dr. Williams.
The operation was not without critics. Xenotransplantation raises the prospect of yet more animal exploitation and can introduce new pathogens into humans, said Cathy Guillermo, senior vice president for animal ethics.
“Using pigs as a replacement source is dangerous to humans, deadly to animals and could lead to the next epidemic,” she said. “It is not possible to eliminate or even isolate all viruses carried by pigs. Researchers should focus on cleaning up the organ donation system and leaving animals alone.
The four-hour operation was carried out by a team of surgeons, including Dr. Nahel Elias, director of the Lagoreta Clinical Transplant Tolerance Center.
The procedure was done under a Food and Drug Administration protocol known as the compassionate use provision, which allows people with life-threatening illnesses to use unapproved treatments. Under the protocol, new drugs are also used to suppress the immune system and prevent organ rejection.
“He is incredibly brave to step forward,” Dr Williams said of Mr Slaman. “Hats off to him. He’s making a big contribution to that.”