Chinese researchers have announced the successful transplantation of a pig kidney to a patient. The scientists also reported taking new steps in the quest for xenotransplantation from animals to humans with a hint that pig livers could also be useful.

A Chinese patient became the third known person to live with a genetically modified pig kidney in the world.

The Chinese research team also reported that a pig liver was transplanted to a person who experienced brain death. Scientists are genetically modifying pigs in hopes of easing the organ shortage by making their organs more similar to human ones. In the US, the first two xenotransplantations (two pig hearts and two pig kidneys) were short-lived. However, the two pig kidney recipients have been successful so far, including a woman transplanted in November and a man transplanted in January.

“KIDNEY WORKING VERY WELL” Dr. Lin Wang from the Fourth Military Medical University Xijing Hospital in Xi’an told journalists this week that the Chinese patient was doing very well around three weeks after the kidney surgery, and the pig kidney was also functioning very well. Wang, who is part of the xenotransplant team, mentioned that the kidney recipient was staying in the hospital for tests. Chinese media reported that the patient is a 69-year-old woman diagnosed with kidney failure eight years ago.

NEXT IS THE LIVER However, Wang indicated a potential next step in xenotransplantation: learning to transplant pig livers.

Yesterday, his team reported in the journal Nature that a pig liver transplanted to a person who experienced brain death had survived for ten days without showing any early signs of rejection. The pig liver produces bile and albumin, essential for basic organ functions though not as much as human livers. Wang stated, “We found that a pig liver could function to some extent in a human.” He estimates this would be enough to assist a failing human liver. Last year in the US, surgeons at the University of Pennsylvania attempted such “bridge” support by externally connecting a pig liver to the body of a person with brain death to filter blood, similar to dialysis for failing kidneys. US pig developer eGenesis is exploring this approach.

“MORE QUESTIONS THAN ANSWERS”

In China, Wang’s team did not remove the deceased person’s own liver but instead placed the pig liver alongside it. Dr. Parsia Vagefi, a liver transplant surgeon at UT Southwestern Medical Center not involved in the study, said this “blurs the lines.” Vagefi said, “Hopefully, this is a first step, but as with any good research, there are more questions than answers.” Wang said his team later replaced another deceased person’s human liver with a pig one and analyzed the outcome. Another Chinese hospital reportedly transplanted a pig liver to a living patient after removing a portion of their cancerous liver last year, though the result of that experiment is unknown.