The world's first pig heart transplant into a human body has been beating normally for three days

Dr. Griffiths performs the surgery and the patient Bennett. Image credit: University of Maryland Medical Center

On Friday, the University of Maryland Medical Center successfully transplanted a gene-edited pig heart into a 57-year-old patient with end-stage heart disease.

On January 10, local time, the University of Maryland Medical Center issued a paper saying that after 3 days, the heart is still performing well, "This organ transplant proves for the first time that the heart of a genetically modified animal can function like a human heart without being immediately rejected by the body." ”

The recipient gets permission on New Year's Eve to say, "Do the transplant or die."

The surgery was performed by Maryland resident David Bennett, who suffered from arrhythmias and was terminally ill and unable to maintain normal cardiopulmonary function without a machine. In addition, he did not wait until the operation to make a human heart available for transplantation.

Shell financial reporter learned that even in the United States, xenotransplantation technology between different organisms has not yet been licensed for use, but according to the "compassionate use" clause of the US Food and Drug Administration (FDA), when patients face serious or life-threatening medical conditions, and there is only one option of experimental therapy, this clause is applied to save patients' lives.

Eventually, on New Year's Eve 2022, Bennett got a special license from the FDA to have the opportunity to receive a pig heart transplant.

"I'm either going to do this transplant or I'm going to die. I want to live. I know it's like shooting in the dark, but it's my last chance. Bennett said the day before the surgery. He has been hospitalized and bedridden for the past few months. "I'm looking forward to getting up when I recover."

Some people engaged in medical research told Shell Financial Reporter that the results of this experimental therapy are difficult to predict, "the biggest risk factor comes from transplant rejection, foreign tissues or organs and other grafts will be recognized by the recipient's immune system as a "different component", and the immune system may launch an immunological response to attack, destroy and clear the graft." In the first 48 hours after transplantation, also known as the ultra-acute rejection phase, ischemia or necrosis of the organ may occur. ”

In fact, this pig heart is not a heart that belongs entirely to pigs in the traditional sense, but has been genetically edited. The University of Maryland Medical Center said they performed 10 unique gene edits in donor pigs — knocking out three genes from pigs that trigger immune rejection and one that causes heart tissue overgrowth, and inserting six genes from humans.

On the morning of the transplant, a surgical team led by Dr. Griffith and Dr. Mohiuddin took the pig's heart and placed it in the XVIVO heart box perfusion device, a machine that preserves the heart all the way to the operation. Doctors also use an anti-rejection drug. In the end, the surgery was a success, and according to a post by the University of Maryland Medical Center, the heart was still performing well three days after receiving the surgical transplant.

Dr Daniel G Maluf, director of transplant programs at the University of Maryland Medical Center, said, "This is a breakthrough in organ transplantation and medicine," he said. "The culmination of years of research and testing by a multidisciplinary team led by Dr Griffith and Dr. Mohidin represents the beginning of a new era in the field of organ transplant medicine, and I am proud of the amazing achievements of our team."

Why did pigs become transplant donors?

In the view of the University of Maryland Medical Center, the reason for the study of transplanting pig hearts to humans is because of the scarcity of organs to be transplanted.

According to the World Health Organization (WHO), less than 10 percent of the world's organ transplant needs are met each year. Currently, there are about 110,000 patients in the United States who are awaiting organ transplants, and more than 6,000 patients die each year before they can get an organ transplant.

China's organ transplant gap is also large. In 2020, Huang Jiefu, chairman of the China Organ Transplant Development Foundation, publicly stated that there are about 300,000 patients waiting for organ transplantation due to terminal organ failure every year, while the number of organ transplants per year is only about 20,000 cases, and the transplant gap is very large, "Organ transplantation is currently an important medical means to save patients with terminal organ failure, but there is no transplant without donation."

The University of Maryland believes that through xenotransplantation, it will be possible to revolutionize the transplant field by eliminating the organ shortage crisis.

In the early 20th century, scientists tried xenotransplantation of orangutans, baboons and other primates that are closely related to humans. For example, in 1984, a baby girl named Stephanie Fae Beauclair in the United States received a heart from a baboon due to left-heart hypoplasia syndrome, becoming the first baby to receive a xenotransplantation transplant. But just 21 days later, she died of immune rejection.

But with the advent of gene editing technology, the direction of xenotransplantation has also changed, and researchers have gradually turned their attention to pigs with more abundant organ sources and large litter yields and rapid maturity.

It is understood that the current cornea of pigs can be successfully transplanted to people, such as 2017 Central South University Xiangya Third Hospital for a 27-year-old youth for a 27-year-old youth for pig cornea transplant surgery, Xiangya Third Hospital Corneal Transplant Center Director Tang Renhong said in an interview with the Beiqing Daily reporter at the time, pig cornea has no blood vessel supply, no matching, the success rate of surgery is as high as 90%, "pig cornea transplantation, not directly transplant the pig's cornea to the human eyeball, but after special process treatment, The three-dimensional structure of the cornea is transplanted to the human eyeball to form a new corneal tissue. Now it is used clinically, mainly because of the lack of human donor cornea in China, and many patients do not have the opportunity to obtain human corneal transplantation, and can only retreat to the second place. ”

In addition to the cornea of pigs, the heart valves of pigs have also been successfully applied in clinical practice. However, the transplantation of a pig heart is the first in the industry.

"This is a breakthrough surgery that brings us one step closer to addressing the organ shortage crisis, as there simply aren't enough donor human hearts to satisfy a long list of potential receptors." Griffith said, "We are proceeding cautiously, but we are also optimistic that this world-first surgery will provide new options for future patients." ”

Edited by Xu Chao Proofread by Chen Diyan