The world's first swine heart transplant patient died two months after surgery

Beijing News shell financial reporter Luo Yidan Editor Song Yuting Proofreading Chen Diyan

On March 9, local time, the University of Maryland Medical Center issued a statement saying that the world's first heart disease patient who received a genetically modified pig heart, Maryland resident David Bennett (David Bennett) died on March 8. Bennett underwent a transplant on Jan. 7, and the pig's heart beat inside his body for more than 2 months.

Previously, in response to Bennett's postoperative survival, Shell financial reporters had sent interview emails to the media liaison officer of the University of Maryland Medical Center, but there was no response. In response to Bennett's death on March 9, Muhammad M. Mohiuddin, a professor of surgery at the University of Maryland and scientific director of the Heart Xenotransplant Program, thanked Mr. Bennett for his unique and historic role in helping to contribute a great deal of knowledge to the field of xenotransplantation, and said clinical trials would continue in the future.

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Surgery is specially licensed

Patients say "either get a transplant or die."

Dr. Griffith and patient Bennett performing the operation Photo/University of Maryland Medical Center

"We are shocked by the passing of Mr Bennett. It turned out that he was a brave and noble patient who fought until the end. We extend our most sincere condolences to his family. Bartley P. Griffith, M.D., who led the transplant team, said, "Mr. Bennett is known to millions of people around the world for his courage and strong will to live." ”

It is understood that Bennett suffers from arrhythmias, the disease has entered the terminal stage, and it is impossible to maintain normal cardiopulmonary function without relying on machines. In addition, he did not wait until the operation to make a human heart available for transplantation. "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.

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. On New Year's Eve 2022, Bennett received a special license from the FDA to have the opportunity to receive a pig heart transplant. On January 10, local time, the University of Maryland Medical Center issued a paper saying that after 3 days of transplantation, 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." ”

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 Griffith and Mohidin removed the pig's heart and placed it in the XVIVO heart box perfusion device, a machine that preserves the heart all the way to surgery. 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.

The University of Maryland said that after the surgery, the transplanted heart performed well within a few weeks without any signs of rejection. Patients are able to spend time with their families and participate in physical therapy to help regain their strength. He watched the TV show Super Bowl with his physical therapist and often talked about wanting to go home and raise his dog.

Responding to Bennett's death, Griffith said, "As with any of the world's first transplants, this one brings valuable insights that promise to inform transplant surgeons to improve outcomes and potentially provide life-saving benefits to future patients." ”

Xenotransplantation is the solution to the organ shortage crisis

The researchers say trials will continue in the future

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.

On March 9, Mohidin said, "We have gained valuable insights into how well genetically modified pig hearts can function well in the human body while the immune system is adequately suppressed, and we remain optimistic and plan to continue our work in future clinical trials."

Duty Editor Gully