December 8, 2021

Pig kidney transplanted to human patient

NYU Langone Health / photo by Joe Carrotta 

The first transplant of a genetically engineered, non-human kidney to a human body was recently completed at NYU Langone Health, marking a major step forward towards an alternative supply of organs.

The kidney was obtained from a genetically engineered pig and transplanted into a brain-dead donor, a woman, who had been kept alive on a ventilator. The donor’s family gave its consent for the procedure.  Doctors studied the kidney’s function and watched for signs of rejection for 54 hours.

Additionally, the pig’s thymus gland, which is responsible for “educating” the immune system, was transplanted with the kidney to stave off novel immune responses to the pig kidney.  

The study was observational, not functional. The kidney was attached to the blood vessels in the upper leg and was outside the abdomen for 54 hours. No signs of rejection were detected 

To some extent, this is science by press release, as the study has not been peer reviewed or published in a journal.

Dr Robert Montgomery, the lead surgeon, described the procedure at a press conference as a “major step forward in creating a sustainable supply of lifesaving organs and hopefully ending the current paradigm that someone has to die for someone to live.”

“The potential here is incredible,” he said. “If the science and experimentation continue to move ahead positively, we could be close to kidney xenotransplantation into a living human being. And the future of this work is not limited to kidneys. Transplanting hearts from a genetically engineered pig may be the next big milestone. This is an extraordinary moment that should be celebrated—not as the end of the road, but the beginning. There is more work to do to make xenotransplantation an everyday reality.”

Others were more guarded in their assessment of the procedure. Similar experiments with primates have also shown promising results, but as Parsia Vagefi, a transplant surgeon at UT Southwestern Medical Center in Dallas, commented, “It’s a proof of principle but it didn’t really move the needle in terms of the science.” The real test is whether a pig’s kidney can survive for years in a human recipient. “Nobody needs a kidney for three days,” said Dr Vagefi.

Is it ethical to genetically engineer pigs and harvest their organs? Some say No. “Pigs aren’t spare parts and should never be used as such just because humans are too self-centered to donate their bodies to patients desperate for organ transplants,” the organization People for the Ethical Treatment of Animals, or PETA, declared.