Richard Slayman was the first living person with a genetically modified pig kidney in his body. He has now died almost two months after the transplant. There is no evidence that the death of 62-year-old Richard Slayman was due to the transplant, Massachusetts General Hospital said on Saturday (local time). It expressed its condolences to the relatives.

Slayman received a human donor kidney in 2018. But this began to fail last year. There were also complications with dialysis. The doctors then suggested implanting a genetically modified pig kidney into him, which was successful in March.

Such a xenotransplantation, in which people are supposed to be cured by transplanting cells, tissue or organs from animals, was considered impossible for decades because the human organism immediately destroyed animal tissue. While pig tissue has been used for years, for example for artificial heart valves, entire animal organs are much more complex. Most recently, attempts have been made to modify them so that they more closely resemble human organs. Later, pig kidneys were temporarily inserted into brain-dead people. Pig hearts have already been transplanted into humans twice. However, the patients died after a few months.

Some of the pig’s genes that are harmful to humans were removed from the kidney implanted in Slayman. The organ also received certain human genes to make it more tolerable for the patient. The doctors hoped that the pig kidney would last at least two years.

Slayman’s relatives thanked the doctors. Their great commitment enabled the family to spend seven weeks together with the sick man, which they will always remember with gratitude. Slayman also underwent the operation to give hope to thousands of people waiting for a transplant. His optimism will endure.