A world first: Man lives withpig kidney for nine months
A genetically engineered pig kidney kept a 66-year-old man off dialysis for a record 271 days before he successfully received a donor organ, marking a major advancement towards using animal organs to “bridge” the widening gap between organ demand and availability.The man, a US resident identified as Tim Andrews, received the modified pig kidney on Jan 25, 2025. He lived with it for nine months. This Sept, his case was announced in a Lancet research paper, which described him as the first human patient to receive a human donor kidney after a pig kidney transplant.Andrews’s doctors, from Harvard Medical School, Massachusetts General Hospital and associated hospitals, detailed his experience and how xenotransplantation (animal to human) had moved closer to its promise of closing the gap between end-stage kidney failure and donor transplantation, allowing a patient to forgo dialysis in the meantime.The case is particularly relevant for India where every year, nearly 2 lakh new patients find themselves in need of a kidney, but only about 14,500 transplants are carried out.“What is truly significant here is the pig kidney provided nearly nine months of dialysis-free renal function and acted as a bridge until a human kidney was available,” said Pune-based senior urosurgeon Dr Sanjay Kulkarni. Andrews received the pig kidney after a USFDA ‘Expanded Access Investigational New Drug’ application, often accepted on compassionate grounds to helGenetically edited animal organ helps elderly patient stay off dialysisA world first: Man lives with pig kidney for nine months tients with life-threatening conditions receive experimental treatments.After the approval, he was monitored for kidney function, rejection, antibody response and potential pig-to-human infection. The pig kidney began working immediately after it was transplanted. There was an early warning on day 14, when the body’s immune T-cells began attacking the kidney, but doctors controlled the rejection and no pig pathogen transmission was detected. For roughly six months, the kidney worked well.The turning point came when Andrews developed a bacterial infection, which was not transmitted from the pig. Doctors then had to reduce the medicines suppressing the immune system. Soon afterwards, inflammation began damaging the lining of the pig kidney’s blood vessels, leading to microscopic blood clots, a condition called thrombotic microangiopathy. The animal kidney progressively stopped working.Andrews was then given a donor kidney from a deceased person, which began to work immediately after the transplant. This proved that exposure to the pig kidney had not trained or sensitised his immune system to attack a future human kidney. Andrew’s levels of anti-HLA antibodies, the antibodies that can make matching and accepting a donor organ more difficult, had not increased.“I would say this is a landmark development in xenotransplantation and an important proof-of-concept for genetically engineered organs. This is the longest a pig organ transplant has worked in a human,” said Dr Arvinder Soin, chief transplant surgeon at Medanta Medicity in Gurugram. “It shows xenotransplantation is finally ready to move from just being a temporary bridge to becoming a source for organs with the potential for longterm survival,” he added. In the last 30 years, experts have found ways to avoid early xenotransplant rejection, and are slowly understanding ways to avoid late rejection as well, resulting in increasingly longer survivals.In India, for now, xenokidneys could offer a temporary renal replacement option for patients without a suitable living donor, while awaiting a deceaseddonor kidney. “The major hurdles include infection and zoonotic surveillance, immunosuppression, graft survival, regulatory oversight, ethical acceptance, genetically engineered animal sourcing, specialised infrastructure and, critically, affordability and access,” Dr Soin said. Also, before xenotransplants become a reality in India, there will have to be major amendments to the Human Organ Transplant Act. “Later, they can be part of routine clinical practice once the survival of such organs equals those of standard transplants from human donors, and the problems listed above are controlled. This would significantly expand the kidney donor pool,” Dr Soin explained.Andrews’ new kidney has been working well. He told reporters in the US that he now spends his time fishing, kayaking and riding his bike. “Every day I wake up, I’m like, this is another extra day because I should’ve been dead a year ago,” he was quoted as saying.
