He Got a Pig Kidney Transplant. Now Doctors Need to Keep It Working

Richard Slayman made history on March 16 by becoming the first living person to receive a genetically edited pig kidney. This week, the 62-year-old Massachusetts resident reached another milestone by being discharged from the hospital after his groundbreaking procedure. Now comes the hard part: making sure his transplanted organ keeps working.

Slayman was on dialysis for end-stage kidney disease when he underwent the four-hour surgery at Massachusetts General Hospital. He said getting to leave the hospital was “one of the happiest moments” of his life, according to a statement released by the hospital. Now, he’s recovering at home. “I’m excited to resume spending time with my family, friends, and loved ones free from the burden of dialysis that has affected my quality of life for many years,” Slayman said in the statement.

A shortage of human donor organs has led researchers to investigate pigs as a potential source. Two patients previously received heart transplants from gene-edited pigs, the first in January 2022 and the second in September 2023. Both individuals died less than two months later and never made it home from the hospital.

Slayman’s medical team says he is doing well, and his new kidney is functioning as it should. “He's doing great. I just saw him this morning. He’s all smiles,” said Leonardo V. Riella, medical director for kidney transplantation at Mass General, in an interview Friday. Slayman’s procedure represents a major test of animal-to-human transplantation, known as xenotransplantation.

About a week after the transplant, Riella says, the team noticed signs of rejection, when the body’s immune system recognizes the donor organ as foreign and starts to attack it. Doctors were able to treat Slayman right away with steroids and drugs that tamp down the immune system.

There are different types of organ rejection. The one Slayman experienced, known as cellular rejection, is the most common. Rejection can occur at any time after transplant, and patients must take immunosuppressive drugs for the rest of their lives to reduce the risk.

Though he’s out of the hospital, Slayman will need to have several in-person medical visits per week so that