Animal to Human transplants

Scientists around the country have been trying to learn how to use animal organs to save human lives for years.  Bodies donated to scientific research offer a remarkable opportunity to help test the theories.

On July 14, 2023, Dr. Robert Montgomery, director of New York University's (NYU) Langone Health and director of their transplant institute, reported to The Associated Press that they have successfully transplanted a pig's kidney into a brain-dead man - and for over one month, it has worked normally.  Dr. Montgomery said, "Is this organ really going to work like a human organ?  So far, it's looking like it is."  This is the latest step toward the advent of an alternate sustainable supply of organs for transplant. 

Attempts at animal-to-human transplants, or xenotransplantation, have failed for decades as people's immune systems attacked the foreign tissue.  Now researchers are using pigs genetically modified so their organs better match human bodies.  Virginia-based Revivicor, Inc. raises these genetically modified pigs and retrieves kidneys that lack a gene that encodes the biomolecule known as alpha-gal, which is responsible for a rapid rejection of the organ by humans.  In another way to help, surgeons attached the pig's thymus to the transplanted kidney in hopes that the gland, which helps train immune cells, would increase human tolerance of the new organ.

The possibility that pig kidneys might one day help ease a dire shortage of transplantable organs persuaded the family of Maurice "Mo" Miller from upstate New York to donate his body for the experiment.  He died suddenly at age 57 with a previously undiagnosed brain cancer, ruling out routine organ donation.  To ensure his body's kidney function was sustained solely by the pig's kidney, both of Mr. Miller's kidneys were removed.  One pig kidney was then transplanted and started producing urine immediately without any signs of rejection.

How long should these experiments last?  University of Alabama at Birmingham (UAB) transplant surgeon Dr. Jayme Locke said that's not clear - and among the ethical questions are how long a family is comfortable or whether it's adding to their grief.  Because maintaining a brain-dead person on a ventilator is difficult, it's also dependent on how stable the donated body is.  Observation on Mr. Miller is ongoing, and this study is scheduled to continue through mid-September 2023.

Dr. Montgomery has a special understanding of transplants.  In addition to being a transplant surgeon, he has received a transplant.  After seven heart attacks, he qualified for a heart transplant, which he received in 2018.  Getting an organ transplant today is a long shot.  According to recent federal Organ Procurement and Transplantation Network (OPTN) data, in the United States, there are more than 103,000 people on the waiting list for a transplant, with nearly 88,000 of those waiting for a kidney.  There are 37 million Americans with chronic kidney disease, and 660,000 people living with kidney failure.  Thousands die while waiting for a transplant; thousands more who could benefit are not even added to the list.

In December 2020, the U.S. Food and Drug Administration (FDA) approved the GalSafe pig as a potential source for human therapeutics, as well as a food source for people who have alpha-gal syndrome, a meat allergy caused by a tick bite.  Many people want to know how soon studies in living patients could start, something the Food and Drug Administration will have to decide.  Dozens of patients and their families have written to Dr. Montgomery, eager to participate in additional studies.

"We have an organ shortage, not just in the U.S., but in the world," said Dr. Locke.  "It's sort of an unmitigated crisis, and it's really challenging for me as a transplant surgeon - to know that even those individuals on the waitlist are going to really struggle to find an organ." 

How can you help?  Sign up to be an organ donor!  You can sign up online by visiting https://www.organdonor.gov/sign-up or by visiting your local department of motor vehicles office.  If you have a living will or advanced health care directive, it should list your wish for donating organs, tissues, or other body parts.  Also, make sure to tell your family of your wishes for donation.