Scientists have successfully transplanted genetically modified pig kidneys into monkeys, leading to potential breakthroughs in organ shortages. In a trial published in the journal Nature, researchers transplanted kidneys from Yucatan breed pigs, genetically modified to improve their chances of not being rejected, into monkeys. The study saw a record amount of time that the monkeys lived with the transplanted kidneys. Currently, over 90,000 people in the United States are awaiting a kidney transplant, with 13 individuals dying each day due to a lack of organ donors. The hope is that this proof-of-concept study will pave the way for human trials and potentially solve the organ shortage crisis.
Kidney problems affect approximately 8% to 16% of people worldwide, and it is a leading cause of death, killing more than 250,000 people in 2019. Dialysis, a common treatment for kidney failure, only does 10% to 15% of the work a healthy kidney would do, and studies show that people on dialysis face a 50% chance of dying within five years. While about 170 million people in the US have signed up to be organ donors, only 3 in 1,000 people die in a way that would make their organs viable for transplantation. Researchers have been exploring alternatives, with some teams studying the possibility of using pig organs due to their anatomical similarities to humans and quick reproduction rates.
The recent trial focused on genetically modifying pigs to make their kidneys less likely to be rejected by another species. Three critical gene modifications were made, including eliminating the genes responsible for producing sugar molecules that could trigger rejection in recipients. The researchers also inserted seven human genes that regulate kidney rejection pathways and inactivated latent retroviruses in the pigs. The combination of these gene edits and immunosuppressive drugs enabled long-term survival and successful kidney function in the monkeys that received the transplants.
The study authors plan to work with the US Food and Drug Administration (FDA) to begin clinical trials in humans. Dr. Robert Montgomery, director of the NYU Langone Transplant Institute, called the trial an “important contribution” and supports moving to human trials sooner rather than later. However, he also warned about the potential safety risks and regulatory challenges associated with introducing a vast array of gene edits. While the results from nonhuman primate models could still pose limitations for pig-to-human transplants, other recent successful pig-to-human transplant cases have provided hope for future organ transplantations, alleviating the burden on the thousands of individuals waiting for life-saving procedures.