NYU Surgeons Claim Advance In Transplant of Pig Kidney To a Human

A genetically altered pig kidney transplanted into a brain-dead man has continued to function for 32 days, an advance toward the possible use of animal organs in humans, surgeons at NYU Langone Health said Wednesday. The Washington Post reports: The kidney was not rejected in the minutes after it was transplanted -- a problem in xenotransplantation, the use of organs from a different species. It began producing urine and took over the functions of a human kidney such as filtering toxins, the physicians said at a news conference. Also Wednesday, researchers at the University of Alabama at Birmingham Heersink School of Medicine published a similar case study, of a brain-dead patient who received two pig kidneys that underwent 10 gene alterations earlier this year. The kidneys were not rejected and continued to function for seven days. The results were peer-reviewed and published in the journal JAMA Surgery. In the NYU Langone transplant, the specially bred pig from which the kidney was procured required just one genetic alteration, to remove a protein that human immune systems attack shortly after surgery. Surgeons also implanted the pig's thymus gland, which helps train the immune system, by sewing it under the outer layer of the kidney, and used immunosuppressive drugs to prevent rejection later on. Managing the condition of the brain-dead man, who on Wednesday still had a heart beat and was breathing with the aid of a ventilator, for an extended period of time also requires extensive efforts by critical care personnel. But the work has revealed information about longer-term use of animal organs, the doctors said. The researchers expect to follow the patient for another month. With the results released Wednesday, both Montgomery and Locke said they can envision moving toward the early stage of clinical trials to identify the safety of transplanting pig kidneys into live humans. [...] The genetic alteration in the NYU Langone study knocked out a carbohydrate molecule known as Alpha-gal, for short. Humans do not produce the substance and create high levels of antibodies against it, which has in the past proven a formidable obstacle to xenotransplantation. "Now that it can be completely removed from the pig, that allows us to move forward," Montgomery said. Still, the team said, pigs have 1,000 proteins that humans don't, and it can take 10 to 14 days to see how a person's immune system reacts to them. Getting beyond that stage with this patient at NYU Langone is a first sign that long-term viability of the organ and patient is possible, they said.

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