Survived 271 days with genetically modified pig kidney transplant

Tim Andrews, a patient with end-stage renal failure linked to type 2 diabetes, survived with a genetically modified pig kidney during the 271 days he waited for a kidney transplant from a human donor.

The organ transplanted to Andrews, who underwent a pig kidney transplant at a hospital in Massachusetts in January 2025, allowed the patient to survive without dialysis for 271 days.

The researchers described Andrews' case as the longest recorded dialysis-free survival in a human after a pig kidney transplant, and also noted that this event was the first successful transition from a pig kidney transplant to a human kidney transplant.

No swine viruses or other swine pathogens were detected in Andrews after the kidney was transplanted, which underwent 69 genomic changes to reduce the risk of immune rejection and prevent transmission of swine viruses, the researchers said.

The researchers stated that after the pig kidney was removed from Andrews' body after 271 days, the patient temporarily returned to dialysis, and that the organ began to function immediately after the patient received a kidney transplant from a human donor in January 2026.

The research into Andrews' organ transplants was conducted by experts from Mass General Brigham's academic medical centers and hospitals.

Leonardo Riella, one of the doctors who conducted the research, stated that this case reveals the potential of "xenotransplantation", an interspecies organ transplant, to address the shortage of human donor organs.

Stating that pig kidneys may initially serve as a temporary solution, Riella also stated that these organs can become a permanent treatment option if their long-term safety and durability can be proven.

However, the researchers pointed out that these findings included only one patient and that further studies are needed to improve immune suppression strategies, genetic engineering and monitoring of organ damage.

The findings of the research on Andrews' organ transplants were published in the journal "The Lancet".