Successful implantation of pig kidneys into two patients offers promising results
Xenotransplantation is the practice of transplanting functioning animal organs into a human recipient. According to the National Kidney Foundation, “On average, 17 people die each day in the United States waiting for an organ transplant.” This results in over 6,000 deaths each year. Because of this national medical crisis, researchers have reached beyond human donors to determine the viability of harvesting animal organs to sustain human life.
Two research groups have successfully transplanted working pig kidneys into humans. The University of Alabama at Birmingham’s Heersink School of Medicine harvested a working pig kidney and transplanted it into a deceased person who was pronounced brain dead and was being maintained on life support. Amazingly, the kidney functioned correctly, eliminating waste and creating urine. The researchers outlined their findings in a recent JAMA Medical news report. The deceased man was in his 50s. He and his family consented to his body being used for scientific advancement.
Dr. Jayme E. Locke wrote in the report,
“For the first time in history, we have shown that a pig kidney can provide life-sustaining kidney function in a human, meaning the kidney made urine as well as cleared toxic substances from the body. We believe strongly that it can alleviate the lethal organ shortage crisis and are hopeful we will be able to move into clinical trials in living persons in the near future.”
In another non-related study, researchers at New York University Langone Health successfully implanted a genetically modified pig kidney into another brain-dead recipient. This pig kidney functioned successfully for 32 days after xenotransplantation, which made it the longest-running successful transplant of its kind. Their study revealed that a genetically modified pig kidney could function for over one month in a human body.
Insight into Xenotransplantation
Xenotransplantation is an experimental treatment, and has not been approved for use in non-brain-dead people. The FDA has not allowed the studies to move into clinical trials at this time. There are ethical concerns regarding the slaying of animals for human survival.
At this time, pigs are the most promising source of kidney xenotransplantation. This is because pigs are widely available, their kidneys are a similar size to humans, and they have a low risk of carrying a disease. The pigs that were used in the aforementioned studies are raised in a lab for this specific purpose. Their genetics are modified to better match a human’s. The two deceased patients used in the studies were given anti-rejection medication so that their bodies would not reject the kidneys.
Doctors and researchers have major concerns when it comes to xenotransplantation. There is always the risk of infection. Kidneys harvested for an animal could carry certain animal-specific germs. This is believed to have been the case with David Bennett, who died two months after receiving a pig heart transplant in 2022. Bennett was later found to be infected with a pig virus, which may have contributed to his death.
Organ rejection is also a danger, but this is possible even with human-to-human organ transplants. Finally, researchers have only proven that pig kidneys can remove waste from blood and create urine. The kidney has other functions it must perform in order to allow a person to live a healthy life. Researchers know more risks could come to light as their studies continue.
Xenotransplantation also raises quite a few ethical concerns. Patients who participate may feel that their privacy is in jeopardy as they will have to be monitored for the rest of their lives. They may experience stigma or bullying from others who will not accept that they received an organ from an animal. Utilizing animal organs will make more organs available and should shorten waiting lists, but questions regarding how organizations ensure the equitable distribution of organs will come into play. And, of course, animal welfare is a concern. The animals used for xenotransplantation must be reared in a lab in a sterile environment, but what quality of life does the animal lead in a lab? Finally, there may be serious religious and cultural implications regarding persons living with a pig organ.
While these two recent studies offer promising solutions to our national organ shortage, medical practitioners are still in the infant stage of research. Many medical and ethical subjects still need to be addressed as doctors continue down this journey of xenotransplantation with lab-reared, genetically-modified pigs. However, with over 6,000 people dying every year as they wait for a transplant, these studies may give hope to those on the transplant waiting list.