A genetically modified pig kidney has been functioning in a human body for 32 days and counting, according to a team of US surgeons.
Both transplants occurred in male patients declared clinically brain-dead, with the permissions of the patients’ families.
Both transplants also involved kidneys that had been genetically modified — with 10 genetic modifications in the 7-day case, but only 1 in the 32-day case.
“This work demonstrates a pig kidney—with only one genetic modification and without experimental medications or devices—can replace the function of a human kidney for at least 32 days without being rejected,” says Dr Robert Montgomery, a professor of surgery at New York University Langone Health, US.
Montgomery performed the transplant on 14 July, and says the patient will continue to be monitored until mid-September.
The genetic modification knocked out the gene that makes a biomolecule called alpha-gal.
This molecule has been shown to trigger “hyperacute rejection”: the immune response in the body that fights back against donated organs.
“We’ve now gathered more evidence to show that, at least in kidneys, just eliminating the gene that triggers a hyperacute rejection may be enough along with clinically approved immunosuppressive drugs to successfully manage the transplant in a human for optimal performance—potentially in the long-term,” says Montgomery.