American surgeons successfully implanted a heart from a genetically modified pig into a 57-year-old man, a medical first that could one day help solve a chronic shortage of organ donations.
The “historic” procedure took place on Friday, the University of Maryland School of Medicine said in a statement Monday. While the patient’s prognosis is far from certain, it represents an important milestone for transplantation from animals to humans.
The patient, David Bennett, was deemed ineligible for a human transplant, a decision often made when the recipient has very poor underlying health.
Now he is recovering and is being carefully monitored to determine how the new organ is working.
“It was either dying or doing this transplant. I want to live. I know it’s a shot in the dark, but it’s my last option, ”the Maryland resident said the day before surgery.
Bennett, who has spent the last few months bedridden with a heart-lung machine, added: “I look forward to getting out of bed after I recover.”
The Food and Drug Administration granted emergency authorization for the surgery on New Year’s Eve, as a last-ditch effort for a patient who was unfit for a conventional transplant.
“This was revolutionary surgery and it brings us one step closer to solving the organ shortage crisis,” said Bartley Griffith, who surgically transplanted the pig heart.
“We are proceeding cautiously, but we are also optimistic that this world’s first surgery will provide an important new option for patients in the future.”
Muhammad Mohiuddin, who co-founded the university’s cardiac xenotransplantation program, added that the surgery was the culmination of years of research, involving pig-to-baboon transplants, with survival times exceeding nine months.
“The successful procedure provided valuable information to help the medical community improve this life-saving method in future patients,” he said.
10 unique genetic edits
Bennett’s donor pig was from a herd that had undergone gene editing procedures.
Three genes that would have led to rejection of pig organs by humans were “knocked out,” as was one gene that would have led to the overgrowth of pig heart tissue.
Six human genes responsible for human acceptance were inserted into the genome, for a total of 10 unique genetic edits.
The edit was done by Virginia-based biotech firm Revivicor, which also supplied the pig used in a groundbreaking kidney transplant in a brain-dead patient in New York in October.
But even though that surgery was purely a proof-of-concept experiment, and the kidney was wired outside of the patient’s body, the new surgery is aimed at saving a person’s life.
The donated organ was kept in an organ preservation machine before surgery, and the team also used a new experimental drug made by Kiniksa Pharmaceuticals along with conventional anti-rejection drugs to suppress the immune system.
About 110,000 Americans are currently waiting for an organ transplant, and more than 6,000 patients die each year before receiving one, according to official figures.
To meet the demand, doctors have long been interested in so-called xenotransplantation, or interspecies organ donation, with experiments dating back to the 17th century.
The first investigations focused on the extraction of organs from primates; for example, a baboon heart was transplanted into a newborn known as the “Baby Fae” in 1984, but it survived for only 20 days.
Today, pig heart valves are widely used in humans, and pig skin is grafted onto human burn victims.
Pigs are ideal donors due to their size, rapid growth and large litters, and the fact that they are already raised as a food source.
Source Credit: TheGuardian
