A 62-year-old man underwent a successful kidney transplant surgery after receiving a genetically modified kidney from a pig (porcine). Richard “Rick” Slayman from Weymouth, Massachusetts who was battling end-stage kidney disease (ESKD) became the first living recipient of a genetically edited pig kidney. The pioneering four-hour-long cross-species transplant surgery was recently carried out at the Massachusetts General Hospital (MGH).
After two weeks of hospital stay post-surgery, Slayman was sent home.
Xenotransplantation: An up-and-coming field
Xenotransplantation or the cross-species transplant is an emerging field that involves the transplantation of cells, tissues, and organs from non-human species to human recipients. Primarily, there have been two modes of organ transplantation—living donor transplantation and deceased donor transplantation. The seminal animal to human transplant has revolutionized the field of transplantation promising to save many lives and improve the quality of life of millions living with organ failure. Currently it is the genetically modified pig kidney transplanted to a person with CKD that has shown promising results as seen in case of Slayman.
Slayman, who has been living with type 2 diabetes and hypertension for several years had previously undergone a deceased donor kidney transplant at MGH in 2018 after being on dialysis for seven years. However, the organ began failing in five years, making him dependent on dialysis all over again in May 2023. The severe complications associated with recurrent dialysis dampened his quality of life, prompting his doctors to consider xenotransplantation and the procedure was conducted on 16th March 2024.
Previously, two persons have received pig heart transplants, however the recipients died a few weeks later.
A step in the right direction
The successful surgery has extended hope in narrowing the glaring gap that persists globally between the demand and supply of organs.
Out of every 100 people awaiting a transplantation, only about 4 manage to secure and undergo a transplant, says Dr Vidyashankar P, lead consultant, nephrology, Aster CMI Hospital, Bangalore.
He further notes that factors including a rise in diabetes, high blood pressure, increasing nuclear families, have led to living donor organ donations also seeing a downward trend.
The acute shortage of organs has been costing lives with over 20 people dying in India each day waiting for an organ. The kidney is the most common organ needed for transplant.
Genetic modification of the organ
According to the press release by MGH, the kidney used was from a pig that was genetically-edited to remove harmful pig genes and add certain human genes to improve its compatibility with humans. Total 69 edits were made on the pig’s kidney.
“The pig kidney is physiologically and anatomically similar to human kidneys, with similar blood supply structure and electrolyte balance, making it suitable for xenotransplantation,” says Dr Puneet Bhuwania, Consultant Nephrologist & Transplant Physician at Wockhardt Hospitals, Mira Road, Mumbai.
However, he adds that there are certain genes in pig kidneys that are harmful for humans, and can give rise to potential complications, thereby necessitating genetic modification.
Inactivating harmful pig virus
Scientists also inactivated porcine endogenous retroviruses (PERVs) in the pig donor to eliminate any risk of infection in humans. These modifications have reduced the risk of organ rejection.
“PERVs are viruses that are present in all pigs, they are harmless to the pig, but can infect humans, through xenotransplantation. Inactivating these viruses evades the risk,” says Dr Vidyashankar.
The press release further said: The procedure was performed under a single FDA Expanded Access Protocol (EAP) – known as compassionate use – granted to a single patient or group of patients with serious, life-threatening illnesses or conditions to gain access to experimental treatments or trials when no comparable treatment options or therapies exist.
“An abundant supply of organs resulting from this technological advance may go far to finally achieve health equity and offer the best solution to kidney failure – a well-functioning kidney – to all patients in need. I commend Mr Slayman, who has been my patient for many years, for his courageousness in becoming a trailblazer in the field of transplantation,” said Dr Winfred Williams, Slayman’s nephrologist.
Dr Bhuwania concludes that if the pig kidney transplant fares well in the long run, other animals such as monkeys can also be considered in the future for xenotransplantation.
Takeaways
In a first, a 62-year-old man underwent a successful pig organ transplant at Massachusetts General Hospital, US. The cross-species transplant has extended hope to bridge the gap between the demand and supply of organs, thereby saving lives and improving the quality of life of many. The donor pig’s kidney was genetically modified to reduce the risks of rejection and infections in the recipient.
