Doctor warns against false hope from pig kidney transplants

Kidney transplants from animals could offer hope to much of the world’s population, but the technology is not there yet, Ragnar Pálsson, a physician and kidney transplant specialist at Massachusetts General Hospital in Boston, told mbl.is.

“We simply have not reached that point yet, even though the development is promising,” he said.

International media, including mbl.is, reported earlier this month that American patient Tim Andrews had lived for 271 days with a pig kidney transplanted at Massachusetts General Hospital on 25 January last year. He was waiting for a human kidney, which he received in a second operation in October.

No one had previously lived so long with a pig kidney. Only a small number of such procedures have been carried out worldwide, using kidneys from Yucatan miniature pigs that have undergone 69 genetic modifications to make their organs more suitable for functioning in humans.

Media reports cited a study in The Lancet, a medical scientific journal, describing the first human study involving patients who received kidneys from genetically modified Yucatan pigs as a temporary solution while waiting on transplant lists.

About 100,000 people are on the kidney transplant waiting list in the United States at any given time, while around 25,000 people there receive a kidney from a human donor each year.

Ragnar was one of 35 authors of the study, all of whom contributed expertise to the research.

Kidneys are a matter of life and death

“I more or less ended up in medicine by accident. I had not intended to become a doctor, but it was the first year that entrance examinations were held, and I decided at the last minute to apply,” Ragnar said.

He said he had always been interested in completing specialist training in the United States because he lived there as a child. His father, Páll Torfi Önundarson, a physician and blood disorder specialist, had also completed specialist training there.

Ragnar moved to the United States in 2012 for specialist training in internal medicine at Duke University in North Carolina. He then began specialist training in nephrology in Boston in 2015 and has worked there since, primarily at Massachusetts General Hospital and also at Brigham and Women’s Hospital, another large teaching hospital affiliated with Harvard University.

He has also worked at Landspítali, Iceland’s national university hospital, and has moved between Iceland and the United States. Since 2024, Boston has been his main place of work.

Ragnar now leads a team at Massachusetts General Hospital that assesses potential kidney donors.