TWO KIDNEYS FROM a genetically modified pig have been transplanted into the body of a human – an achievement hailed as a “game-changing moment in the history of medicine”.

The process shows the procedure may be viable in the long term and how such a transplant might work in the real world, researchers say.

Experts now hope to carry out a clinical trial on living humans with serious kidney problems.

The transplanted organs were able to carry out the functions of kidneys, scientists from the University of Alabama (UAB) in the US report.

They successfully filtered blood, produced urine, and were not immediately rejected.

According to the study, the kidneys continued working until 74 hours later.

The transplant recipient, who was medically classed as “brain dead”, was a 57-year-old man called Jim Parsons who was kept alive on a ventilator.

The results demonstrate how this kind of transplantation from one species to another, known as xenotransplantation, could address a global organ shortage, the study’s lead surgeon, Dr Jayme Locke, said.

Dr Locke, director of the Comprehensive Transplant Institute in the UAB’s Department of Surgery, added: “This game-changing moment in the history of medicine represents a paradigm shift and a major milestone in the field of xenotransplantation, which is arguably the best solution to the organ shortage crisis.

“We have bridged critical knowledge gaps and obtained the safety and feasibility data necessary to begin a clinical trial in living humans with end-stage kidney failure disease.”

She added: “The concept of being able to have an organ waiting on the shelf, waiting for the person who needs it, is just remarkable to think about – and exciting for that person.”

Selwyn Vickers, dean of the UAB Heersink School of Medicine and chief executive of the UAB Health System and UAB/Ascension St. Vincent’s Alliance, said: “Today’s results are a remarkable achievement for humanity and advance xenotransplant into the clinical realm.”

Since the early 2000s, researchers have tried many times to genetically modify pigs through changes that reduce the chance of the transplant being rejected.

Some 10 genes were changed in this latest donor pig. Four were disabled pig genes, also known as knockouts, and six were human genes that were cloned into the pigs, also known as knock-ins.

The human genes were added to the pig with the aim of helping to prevent rejection, both immediately and months or years down the line.

The natural lifespan of a pig is 30 years, they are easily bred, and can have organs of similar size to humans.

The procedure was conducted in much the same way that a human kidney transplant is carried out and, before the surgery, the recipient and donor animal even underwent a crossmatch compatibility test to see if they were a good tissue match.