NewsPig kidney transplant breakthrough offers hope for organ shortage

Pig kidney transplant breakthrough offers hope for organ shortage

Doctors at Massachusetts General Hospital transplanted a pig kidney into a 66-year-old patient with end-stage kidney disease. The surgical team reported that the new kidney is functioning as expected. They performed the first such operation in March 2024.


Surgeons transplant a pig kidney to a patient. This is the second such operation performed by this team.
Surgeons transplant a pig kidney to a patient. This is the second such operation performed by this team.
Images source: © mass general | Kate Flock

Surgeons at Massachusetts General Hospital, led by physician-scientists from Harvard Medical School, successfully transplanted a genetically modified pig kidney into a living person for the second time, according to press releases published on the websites of MGH and HMS. The 2.5-hour procedure was performed on Saturday, January 25, 2025, but the public was only informed on February 7. The same team conducted the world's first such operation in March 2024.

Xenotransplantation: A hope for humanity

The results of the recent xenotransplantation (transplantation of a modified animal organ to a human) indicate progress and bring hope to doctors and scientists. They hope this procedure can help alleviate organ shortages and save human lives. Specialists believe xenotransplantation can help reduce health disparities in organ failure and transplant access.

- This second xenotransplant provides us with another excellent opportunity to learn how we can make genetically edited pig organs a viable, long-term solution for patients - said the chief surgeon Tatsuo Kawai, professor of surgery at HMS and director of the Legorreta Center for Clinical Transplant Tolerance (CCTT) at Mass General, as quoted in the press release. - Although we have a long way to go to make that a reality, this transplant is an important next step that has given us optimism to achieve that goal - he added.

The patient who received the kidney transplant in January this year is a 66-year-old resident of New Hampshire, Tim Andrews. He is the fourth person in the world to receive a genetically modified pig kidney and one of two currently living recipients (the first in the world died two months after the transplant due to unrelated reasons).

Andrews had been on dialysis for over two years due to end-stage kidney disease. The treatment severely affected his daily life, causing fatigue and an inability to perform routine tasks. Andrews also experienced serious complications, including a heart attack in July 2023.

His path to a kidney transplant was further complicated by his O blood type, which makes people universal donors but limited recipients, as they can only receive organs from donors with the same blood type. While most patients wait for a kidney for 3 to 5 years, people with blood type O+ or O- often wait 5 to 10 years, further reducing their chances of receiving an organ from a donor.

After being discharged from Mass General Hospital on February 1, Andrews no longer needs dialysis for the first time in over two years. The surgical team reported that his new kidney is functioning as expected.

Thousands waiting for transplants

The United Network for Organ Sharing (UNOS) reports that over 100,000 people in the United States are waiting for an organ transplant, with 17 dying each day. Meanwhile, according to the Organ Procurement and Transplantation Network (OPTN), about 90,000 people were waiting for a kidney in November 2024.

Similar to the groundbreaking surgery in 2024, the pig kidney was provided by eGenesis, a company specializing in xenotransplantation therapy. The kidney had 69 genomic edits made using CRISPR/Cas9 technology (a genetic engineering method allowing for genome manipulation of a given organism).

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