A team of surgeons in Boston, in the United States, has completed for the first time the transplant of a kidney from a genetically modified pig into a 62-year-old man suffering from terminal renal disease. As underlined by the New York Times, this is the first procedure of this kind performed successfully on a living patient: other attempts had been made in the past but on brain-dead patients. If this technique proves successful, it could offer new hope to thousands of people with kidney disease. As reported by Massachusetts General Hospital, the signs so far are promising: The kidneys remove waste products and excess fluid from the blood, and the new kidney began producing urine shortly after surgery last weekend. The patient is already able to walk in the hospital corridors and could be discharged soon.
The first case in the world
This world premiere opens up different perspectives. A new source of kidneys “could solve a long-standing problem: minority patients’ inadequate access to kidney transplants,” noted Winfred Williams, MD, of Mass General, the patient’s treating nephrologist. And there’s another aspect: If kidneys from genetically modified animals could be transplanted on a large scale, dialysis would also “become obsolete,” hypothesizes Leonardo V. Riella, medical director for kidney transplants at Mass General.
Boston transplant patient Richard ‘Rick’ Slayman, a supervisor for the state Department of Transportation, had suffered from diabetes and hypertension for many years and had been treated at Mass General for more than a decade. His kidneys failed and he has since been on dialysis for 7 years, finally receiving a human kidney in 2018. But the donated organ also failed and developed other complications. So Slayman resumed dialysis in 2023. Unfortunately, however, he had serious vascular complications and recurrent hospitalizations began for him, Williams explained. Finally again the waiting list for another organ. “He was becoming more and more discouraged, he said he just couldn’t go on like this,” the doctor said. “I started thinking about the extraordinary measures we could take,” given that he “would have to wait 5 to 6 years to get a human kidney. He wouldn’t be able to survive.” When Williams suggested Slayman receive a pig kidney, after many questions the patient decided to proceed. “I saw it – the man said in a statement provided by the hospital – not only as a way to help me, but as a way to give hope to thousands of people who need a transplant to survive.” Doctors will now continue to monitor him for any signs of rejection.
Transplantation from an animal to man
Xenotransplantation – the implantation of an animal organ into a human – has been proposed for decades 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 point out that long-term rejection can occur even when donors are well-matched. In recent years, however, there have been several scientific advances that have brought this goal closer, making it possible to modify animal genes to make organs more compatible and less likely to be rejected by the immune system. The transplanted kidney came from a pig engineered by the biotechnology company eGenesis, which removed three genes involved in the organ’s potential rejection. Furthermore, 7 human genes have been inserted to improve human compatibility. Pigs carry retroviruses that can infect humans, and the company has also inactivated the pathogens.
All of the above
As for precedents, it was September 2021 when surgeons at NYU Langone Health in New York ‘connected’ a kidney from a genetically modified pig to a brain-dead man. This is how the organ was observed to begin functioning and producing urine. Shortly thereafter, scientists at the University of Alabama at Birmingham announced that they had performed a similar procedure with similar results. And always in this vein, surgeons at the University of Maryland have twice transplanted hearts from genetically modified pigs into patients suffering from heart disease. However, both patients died shortly afterwards. The intervention was not free from criticism. For Kathy Guillermo, senior vice president of Peta (People for the Ethical Treatment of Animals), xenotransplantations raise the prospect of further exploitation of animals and could introduce new pathogens into human populations.