Medical breakthrough: «He will live forever»
Scientists have made a new breakthrough in medicine: a transplanted pig kidney continues to function for more than a month in the body of a brain-dead person. This achievement marks the longest working porcine kidney that is active in a human, paving the way for surgery on living patients.
A pig kidney transplanted by surgeons to a brain-dead man continued to function normally for more than a month – a critical step towards an operation that the New York team hopes to eventually test on living patients.
The latest experiment, announced on Wednesday by NYU Langone Public Health, finds the longest lifespan of a human pig kidney, albeit deceased, has yet to end, according to The Guardian. Researchers will monitor the functioning of the kidneys during the second month.
“Will this organ really work like a human? As long as everything looks as it is”, – Robert Montgomery, director of the NYU Langone Transplant Institute, told The Associated Press.
“It looks even better than a human kidney”– Montgomery said on July 14 after replacing a deceased man's kidney with a single genetically engineered pig's kidney and watching it immediately begin to excrete urine.
Scientists across the country are racing to learn how to use animal organs to save human lives, and organs donated for research are a wonderful rehearsal. More than 100,000 patients are on the national transplant list, and thousands die waiting each year, according to the Associated Press.
The possibility that pig kidneys could one day help deal with a severe shortage of transplantable organs convinced the family of 57-year-old Maurice “Mo” Miller from upstate New York to donate his body for the experiment.
“I had my doubts about it, – his sister Mary Miller-Duffy told the AP. – But he liked helping others, and I think that's what my brother would like. So I offered them my brother. He will be written about in medical books, and he will live forever”.
Attempts to transplant organs from an animal to humans have failed for decades as people's immune systems attacked foreign tissue, the Associated Press emphasizes. Researchers are now using pigs that have been genetically engineered to make their organs better match human bodies.
Last year, under special regulatory approval, surgeons at the University of Maryland transplanted «redacted» genes from a pig's heart as a last-ditch effort to save a dying man. He lived only two months before the organ failed for reasons that are not fully understood, but provide lessons for future attempts.
Now the US Food and Drug Administration is considering whether to allow multiple small but thorough studies on transplanting a porcine heart or kidney into volunteer patients.
The NYU experiment is one of a series of developments aimed at accelerating the start of such clinical trials. Also on Wednesday, the University of Alabama at Birmingham (UAB) reported another major success: a pair of pig kidneys functioned normally inside another donor body for seven days.
The kidneys perform a wide range of functions in the body in addition to producing urine. In the journal Jama Surgery, UAB transplant surgeon Dr. Jaime Locke reported on laboratory tests documenting the work of genetically modified pig organs. She said the week-long experiment demonstrated that they can «provide life-sustaining kidney function.»
These experiments are critical to answering other remaining questions «under conditions where we do not put anyone's life at risk.» danger”,– said Montgomery, an NYU kidney transplant surgeon who has also had a heart transplant himself and is acutely aware of the need for a new source of organs.
The operation itself is not much different from the thousands he has performed before, «but somewhere deep down you realize the enormity of what you are doing … realize that this can have a huge impact on the future of transplantation,» – said Montgomery.
The operation was carefully timed. Early that morning, doctors Adam Griesemer and Jeffrey Stern flew hundreds of miles to the facility where Virginia-based Revivicor Inc. contains genetically modified pigs, and extracted kidneys that lack a gene that would cause immediate destruction by the human immune system.
As they raced back to New York University, Montgomery removed both kidneys from the donor body to avoid there was no doubt that a pork version would arrive soon. One pig kidney was transplanted, the other – saved for comparison at the end of the experiment.
“You are always nervous”– Grisemer said. Seeing it all start so quickly, «I experienced a lot of thrills and a great sense of relief.»
How long are these experiments supposed to last? Locke of Alabama said it was unclear, and among ethical issues – how long the donor's family will feel comfortable and whether this will aggravate their grief. Since it is difficult to keep a brain dead person on a ventilator, the decision also depends on how stable the donor body is.
In her own experiment, the donor body was quite stable, and if the study did not need to end in a week , “I think we could hold out much longer, which I think is very promising”, – she said.
Dr. Muhammad Mohiuddin of the University of Maryland warns that it's unclear how closely a deceased body will mimic a living patient's response to a pig organ, but this study educates the public about xenotransplantation so «people aren't shocked» when it's time to try again with the living.