Xenotransplantation, or the transplantation of non-human animal cells into humans, is seen by some as the future of medicine. However, transplantation of organs from pigs to humans hasn’t yet produced long-lasting results.
USA Today reported Tuesday that all four patients who have received pig organ transplants have died. Lisa Pisano, 54, was the latest to pass away.
“All I want is the opportunity to have a better life,” said Pisano of her transplant, according to NYU Langone Health. “After I was ruled out for a human transplant, I learned I didn’t have a lot of time left. My doctors thought there may be a chance I could be approved to receive a gene-edited pig kidney, so I discussed it with my family and my husband. He has been by my side throughout this ordeal and wants me to be better.”
She received her gene-edited kidney kidney April 12, along with a special pump. However, it was removed May 29. Dr. Robert Montgomery, who helped lead her care team at NYU Langone, explained in a statement cited by USA Today that it failed due to medications that supported Pisano’s blood pressure.
“Lisa’s contributions to medicine, surgery, and xenotransplantation cannot be overstated,” said Montgomery, director of the NYU Langone Transplant Institute. “Her bravery gave hope to thousands of people living with end-stage kidney or heart failure who could soon benefit from an alternative supply of organs.”
According to USA Today, the three other pig organ transplant recipients died within months of their operations. It also said “researchers have been trying for years to gene-edit animals to make them suitable for organ transplants.”
Other recipients included two patients who had heart transplants at the University of Maryland in 2022 and 2023 and 62-year-old Richard ‘Rick’ Slayman of Weymouth, Mass. He received the first successful pig kidney transplant in March. His kidney was from a pig donor that was genetically-edited using CRISPR-Cas9 technology to remove harmful pig genes and add certain human genes to improve its compatibility with humans, said Massachusetts General Hospital.
“Seventy years after the first kidney transplant and six decades following the advent of immunosuppressive medications, we stand on the brink of a monumental breakthrough in transplantation,” said Leonardo V.
Riella, the hospital’s medical director for kidney transplantation.
In a May press release, the hospital revealed that Slayman, who suffered from Type 2 diabetes, had passed away.
“The Mass General transplant team is deeply saddened at the sudden passing of Mr. Rick Slayman. We have no indication that it was the result of his recent transplant. Mr. Slayman will forever be seen as a beacon of hope to countless transplant patients worldwide and we are deeply grateful for his trust and willingness to advance the field of xenotransplantation. We offer our heartfelt condolences to Mr. Slayman’s family and loved ones as they remember an extraordinary person whose generosity and kindness touched all who knew him,” read a statement.
Slayman’s family said they “take great comfort” in knowing his story inspired many people waiting for organ transplants.
According to the United Network for Organ Sharing, there were more than 27,000 kidney transplants last year alone. A study published in the JAMA Surgery journal last year said an organ shortage continued to be a “crisis” for people with end-stage kidney disease.
USA Today said this week that more than 100,000 Americans are waiting for organ donations to become available.
“Organs typically become available following a tragedy to another family,” said the outlet. “Many others, like Pisano, will never qualify for a transplant waitlist because they have been deemed too ill or otherwise not a good candidate for a transplant.”
Pig transplants aren’t the only type of xenotransplantation doctors have attempted. In the 1980s, a baby lived for 21 days after receiving a baboon heart, according to Loma Linda University Health. While doctors and researchers are determined to keep pushing xenotransplantation forward, there are certain hurdles that may be preventing these transplants to work.
A study published this year in the Frontiers in Immunology journal said that “despite tremendous progress, recent data including the first clinical case suggest that gene-modification alone will not overcome all xenogeneic immunologic barriers.”
In particular, it noted that there are concerns about immunologic barriers (especially with pigs compared to primates) and transmission of zoonotic infections.
“There are the scientific and medical questions of what specific genetic modifications are most effective in making pig organs viable in human bodies, and what accompanying interventions will help human immune systems accept xenotransplanted organs,” said an article on the subject from Columbia Surgery.
It may not be a story about the transplantation of an entire organ, but Audacy has reported on the success of a procedure that saw animal material implanted into human patients successfully. Researchers implanted pig collagen material in 20 subjects with an advanced eye disorder “to reshape the native corneal stroma without removing existing tissue or using sutures,” and observed no adverse events during a two-year follow up.