Towana Looney donated one of her kidneys to her mother in 1999 and lived on dialysis for eight years after a pregnancy complication damaged her remaining kidney. This American from Alabama, in the southern United States, had been waiting for a transplant since 2017 and could not find a compatible donor. As her medical condition deteriorated, she was allowed to receive a genetically modified pig kidney. “I’m full of energy, I have an appetite,” she assured Tuesday, continuing with a laugh: “and of course I can go to the bathroom!” Towana Looney should be able to return home in three months, the medical team said.
This type of transplantation called xenograft, between animal and human, nourishes the hope of responding to the chronic shortage of organ donations in a country where more than 100,000 patients are on the waiting list, including more than 90,000 for one. kidney.
Two previous transplants ended in deaths
Three weeks after the operation, the patient presents “normal kidney conditions,” said surgeon Robert Montgomery, a member of the medical team.
A hospital in Boston and NYU Langone in New York have already transplanted pig kidneys into two other living patients, Rick Slayman and Lisa Pisano, earlier this year. But the latter, seriously ill, died a few weeks later.
Towana Looney, whose general health is better than that of these previous patients, benefited from a kidney with ten genetic modifications, compared to only one for the organ transplanted earlier by the New York team. These modifications of the pig’s DNA are intended to improve biological compatibility between the animal and humans and prevent the organ from being immediately rejected by the recipient’s body.
A new drug combination was also tested in this latest transplant.
Highly anticipated clinical trials
The medical team announced Tuesday that the company Revivicor, which supplied the transplanted kidney, would ask the American authorities for authorization to launch clinical trials starting next year on the two types of kidneys developed.
“This is a watershed moment for the future of transplantation,” said Kevin Longino of the National Kidney Foundation (NKF), an association dedicated to kidney disease, in a statement Tuesday.
According to a survey of its members, patients want, despite the associated risks, rapid access to clinical trials due in particular to the “disabling effects of dialysis: exhaustion, isolation and inability to lead a normal life.”
“Every day, an average of fourteen Americans die while waiting for a life-saving organ transplant, underscoring the need to explore alternative solutions,” insists the foundation.
Progress on xenograft
Long confined to science fiction, xenotransplantation has recently benefited from progress made in gene editing and control of the immune system response, limiting the risks of rejection. “The next goal is to extend the life of these kidneys, including giving them to healthier people who have a better chance of living longer,” explained Robert Montgomery.
Several other transplants of this type have been carried out by his team in recent years, including the world first of a transplant of a pig kidney on a brain dead patient, in September 2021. The organ then functioned well for a few days.
Another American scientific team carried out in 2022 the world’s first transplant of a porcine heart into a living human. But the man, operated on by surgeons from the University of Maryland, died two months after his operation.
Scientists are optimistic because the transplanted organs were not immediately rejected by the patients’ bodies. “We learned a lot from each transplant. We now know a lot about what the pig kidney can do,” assured surgeon Robert Montgomery.
