Genetically Modified Pig Kidney Serves as Record Breaking Bridge to Human Transplant

A 66 year old man with end stage kidney disease survived for nine months with a genetically modified pig kidney before receiving a human transplant. The patient, Timothy Andrews, suffered from kidney failure caused by type 2 diabetes and had only a 9 percent chance of receiving a human organ within five years. The procedure, performed at Mass General Brigham in the United States, marks the first time a pig kidney has been used as a temporary bridge to a human organ. The details of the case were published in the medical journal The Lancet.

The pig kidney, sourced from a Yucatan miniature pig named Wilma, underwent 69 genetic modifications. These edits included the removal of three pig genes that could cause rejection, the addition of seven human genes, and the inactivation of viruses that could cause disease in humans. The organ remained functional for 271 days, which is more than double the previous record for xenograft survival. During this period, Andrews remained free of dialysis and reported a significant improvement in his quality of life.

After approximately six months, damage developed in the blood vessels of the pig kidney, eventually leading to organ failure. Following a period back on dialysis, Andrews received a kidney from a deceased human donor. Medical teams noted that no new antibodies against human tissue were detected, meaning the pig kidney did not hinder the success of the subsequent human transplant. Dr. Leonardo Riella, director of the renal transplant program, stated that xenotransplantation could help address the global organ shortage, either as a bridge to a human donor or eventually as a permanent therapy.

The medical team cautioned that this was a single patient case involving careful selection and intensive care that may not be widely available. While the procedure is a scientific milestone, the team noted that human transplants remain the priority treatment.