Introduction
In the United States, the demand for critical kidney transplants has reached an unprecedented level and is expected to continue to rise in the future. Currently, there are over 90,000 individuals in the US alone who are awaiting this life-saving procedure. Unfortunately, only one-third of the individuals in need will receive a transplant. Consequently, it is estimated that over 10 individuals pass away each day while waiting for a transplant.
Breakthrough
In an effort to address the increasing demand for kidney transplants, researchers have expanded their search beyond human donors and are now exploring the potential of utilizing pig kidneys. The idea of transplanting animal organs into humans, also known as xenotransplantation, has been around for centuries, but only in the last few years have there been big strides toward making this idea a reality. In 2021 the first transplant of a genetically modified pig kidney into a human body was performed at NYU Langone Health in New York City. Just 2 years later, on July 14, surgeons at NYU Langone Health transplanted a genetically engineered pig kidney that continued to function well for a total of 61 days in a brain-dead man, making this the longest period a gene-edited pig kidney has functioned in a human.
How did it work?
Usually, transplanting a pig kidney into a human body would cause rejection immediately because of the presence of a sugar called alpha-gal. alpha-gal is present in pigs and other mammals, but not in humans. To stop immediate rejection, scientists transplanted a kidney from a gene-edited pig which was genetically engineered to eliminate the gene that produces alpha-gal. This pig came from a herd of 100 engineered pigs being raised in a tightly controlled facility in Iowa. The gene alterations in these pigs were approved for human food consumption and medicine by the FDA in December, but more paperwork will need to be filed before pig organs can be transplanted into living humans. "This is an important step forward in realizing the promise of xenotransplantation, which will save thousands of lives each year in the not-too-distant future," said United Therapeutics CEO Martine Rothblatt in a statement.
Future
Although this pig kidney functioned well for around 61 days in the human body, there is still much more research that needs to be done before pig kidneys can become mainstream. Researchers are still working diligently to make a world where receiving life-saving transplants is not a privilege, but an expectation.
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