Successful Transplant of Porcine Heart into Adult Human

In a first-of-its-kind surgery, a 57-year-old patient with terminal heart disease received a successful transplant of a genetically-modified pig heart and is still doing well three days later. It was the only currently available option for the patient. The historic surgery was conducted by University of Maryland School of Medicine (UMSOM) faculty at the University of Maryland Medical Center (UMMC), together known as the University of Maryland Medicine.

This organ transplant demonstrated for the first time that a genetically-modified animal heart can function like a human heart without immediate rejection by the body. The patient, David Bennett, a Maryland resident, is being carefully monitored over the next days and weeks to determine whether the transplant provides lifesaving benefits. He had been deemed ineligible for a conventional heart transplant at UMMC as well as at several other leading transplant centers that reviewed his medical records.

 “It was either die or do this transplant. I want to live. I know it’s a shot in the dark, but it’s my last choice,” said Mr. Bennett, the patient, a day before the surgery was conducted. He had been hospitalized and bedridden for the past few months.  I look forward to getting out of bed after I recover.

The U.S. Food and Drug Administration granted emergency authorization for the surgery on New Year’s Eve through its expanded access (compassionate use) provision. It is used when an experimental medical product, in this case the genetically-modified pig’s heart, is the only option available for a patient faced with a serious or life-threatening medical condition. The authorization to proceed was granted in the hope of saving the patient’s life.

“This was a breakthrough surgery and brings us one step closer to solving the organ shortage crisis. There are simply not enough donor human hearts available to meet the long list of potential recipients,” said Bartley P. Griffith, MD, who surgically transplanted the pig heart into the patient. Dr. Griffith is the Thomas E. and Alice Marie Hales Distinguished Professor in Transplant Surgery at UMSOM. “We are proceeding cautiously, but we are also optimistic that this first-in-the-world surgery will provide an important new option for patients in the future.”

Considered one of the world’s foremost experts on transplanting animal organs, known as xenotransplantation, Muhammad M. Mohiuddin, MD, Professor of Surgery at UMSOM, joined the UMSOM faculty five years ago and established the Cardiac Xenotransplantation Program with Dr. Griffith. Dr. Mohiuddin serves as the program’s Scientific/Program Director and Dr. Griffith as its Clinical Director.

“This is the culmination of years of highly complicated research to hone this technique in animals with survival times that have reached beyond nine months. The FDA used our data and data on the experimental pig to authorize the transplant in an end-stage heart disease patient who had no other treatment options,” said Dr. Mohiuddin.The successful procedure provided valuable information to help the medical community improve this potentially life-saving method in future patients.

Source: https://www.medschool.umaryland.edu/

Gene-Editing: From Pigs To Humans

If any swine is fit to be an organ donor for people, then the dozens of pigs snuffling around Qihan Bio’s facility in Hangzhou, China, may be the best candidates so far. The Chinese company and its U.S. collaborators reported today that they have used the genome editor CRISPR to create the most extensively genetically engineered pigs to date—animals whose tissues, the researchers say, finally combine all the features necessary for a safe and successful transplant into humans.

This is the first prototype,” says Luhan Yang, a geneticist at Qihan Bio. In a preprint published today on bioRxiv, Qihan researchers and collaborators, including Cambridge, Massachusetts–based eGenesis—which Yang co-founded with Harvard University geneticist George Church—described the new generation of animals and various tests on their cells; the researchers have already begun to transplant the pigs’ organs into nonhuman primates, a key step toward human trials.

Qihan and eGenesis aren’t alone in their quest. Several academic and commercial research groups are racing to make up a shortage of life-saving human organs with the comparably sized hearts, kidneys, and livers of pigs. For these cross-species transplants, also known as xenotransplants, the pig’s genome must be re-engineered so that its organs will get along with the new host body. Pigs produce species-specific molecules that set off the human immune system, prompting rejection. Their tissue can also cause abnormal clotting and bleeding when it interacts with human blood. And the pig genome is littered with DNA sequences from viruses that infected the animals long ago and slipped genes into their chromosomes. These sequences, known as porcine endogenous retroviruses (PERVs), have been shown to produce potentially infectious viral particles, though their risk to humans is unclear.

Source: https://www.sciencemag.org/