Pig kidney transplant to human: why this animal?

On Thursday (March 21), the world celebrated the success of the first genetically modified pig kidney transplant into a person. In a statement, Massachusetts General Hospital (MGH) in Boston, United States, described the pioneering procedure as a “historical milestone” in the emerging field of xenotransplantation, which is the transfer of organs or tissues between different species.

The operation caused even more discussion in the country because it was led by Brazilian doctor Leonardo Riella, director of kidney transplantation at MGH, being the first time that a pig kidney transplant was performed on a living patient. But why is this animal’s organ the most suitable for transplantation? MinhaVida clarified this issue. Follow along!

As announced by the hospital, the recipient of the transplanted pig kidney was a 62-year-old man with advanced stage kidney disease. The surgery took place last Saturday (March 16) and was led not only by the Brazilian doctor, but also by the director of the Logorreta Center for Clinical Transplant Tolerance, Tatsuo Kawai, and Nahel Elias, interim head of Transplant Surgery and director of Surgery of Kidney Transplantation.

The procedure received authorization from the FDA (Food and Drug Administration), the equivalent of Anvisa in the United States. The approval, granted under the Expanded Access Protocol, allows a single patient or group of patients with serious and life-threatening illnesses to access experimental treatments when other treatment options or therapies are not available.

The pig kidney recipient had previously undergone a human kidney transplant, but the organ began to fail in 2023. Faced with this situation, the doctors responsible for his case proposed a pig kidney transplant.

Read also: World Kidney Day – do you take good care of your kidneys?

You must be asking yourself: Why was the pig kidney chosen for transplantation? This animal was selected by doctors because it has a kidney size similar to that of humans. And there’s more: according to information from the hospital, the pig kidney to become suitable for transplantation had to undergo 69 genomic changes before being transplanted to the patient.

The organ was provided by eGenesis, a pharmaceutical company in Cambridge, Massachusetts, from a pig that was genetically modified using technology to remove harmful porcine genes and add human genes, with the aim of improving its compatibility with humans. Additionally, scientists deactivated retroviruses present in the pig donor to eliminate any risk of infection in humans.

Over the past five years, MGH and eGenesis have carried out extensive research in the field of xenotransplantation.

João Brunhara says that the traditional kidney transplant can be received by both a living donor and a deceased donor, and details how the procedure is carried out: “During kidney transplantation, the donated kidney is positioned in the iliac fossa of the abdomen and its arteries and veins are connected to the recipient’s iliac vessels. Furthermore, the ureter of the transplanted kidney is connected to the bladder to allow the elimination of urine produced,” said the doctor in a previous interview with My life.

Pig kidney transplantation into humans, also known as xenotransplantation, is carried out in a very similar way to traditional kidney transplantation, with the exception of some significant distinctions. In this procedure, the pig’s kidney is carefully adapted to fit the human body:

The arteries and veins of the pig kidney are connected to the recipient’s blood vessels, allowing adequate circulation of blood to the new organ. Furthermore, the ureter of the porcine kidney is connected to the patient’s urinary system, allowing adequate elimination of the urine produced by the transplanted organ. This meticulous adaptation aims to ensure the proper functioning of the pig kidney in the human body and minimize the risk of post-transplant complications.

According to the Ministry of Health, more than 60 thousand people in Brazil are waiting for an organ for transplant. Of these, more than 37 thousand are awaiting a kidney transplant. Xenotransplants represent hope for this, but since they are not yet a reality worldwide, the greatest solution remains human transplantation. Be a donor and keep this line moving!

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