MercoPress. South Atlantic News Agency

Advances announced in pig kidneys transplanted to humans

Xenotransplantation would bring on a whole new set of opportunities for patients in need of organs

Physicians at New York University's Langone Health Medical Center have managed to keep the kidney of a genetically modified pig to function in a patient's body for 32 consecutive days, it was reported this week.

The transplant took place on July 14 in a 57-year-old patient who had died, but whose heart continued to pump through mechanical assistance. The 32 days represent “the longest period in which a genetically modified pig kidney has functioned in a human,” according to a statement from the surgeons.

Also this week, an investigation from the University of Alabama published in the journal JAMA Surgery mentioned that two modified pig kidneys functioned for seven days in another brain-dead patient.

The New York research, which will continue through mid-September, marks the fifth xenotransplantation at NYU Langone Hospital, was led by Robert Montgomery, M.D., chairman of its Department of Surgery and director of the institution's Transplant Institute.

Unlike previous procedures involving up to ten genetic modifications in porcine organs, this study focused on a kidney that had a single genetic modification in a precise and specific manner. Continued progress in the field of xenotransplantation promises to open new perspectives in the field of transplantation and regenerative medicine.

“This work demonstrates that a pig kidney, with only one genetic modification and without medications or experimental devices, can replace the function of a human kidney for at least 32 days without being rejected,” indicated the surgeon, who performed the first xenotransplantation of this type in September 2021.

The first problem with xenotransplantation is the “hyperacute rejection” that occurs in a matter of minutes when an animal organ is connected to the human circulatory system, but if the gene responsible for this rapid rejection, called “alpha-gal” and which operates through antibodies, is “eliminated,” this rejection can be avoided.

“We have now gathered more evidence showing that, at least in kidneys, just eliminating the gene that triggers hyperacute rejection may be enough, along with clinically approved immunosuppressive drugs, to successfully manage the transplant in a human and have it function optimally, potentially in the long term,” the surgeon said.

The kidney and thymus gland transplanted into the patient came from a “GalSafe” pig, a genetically modified animal by the biotech company Revivicor, which was given the green light by US authorities “as a potential source for human therapies and a food source for people with the alpha-gal syndrome,” a meat allergy triggered by the bite of a type of tick.