Doctors at the University of Maryland in the USA conducted another study Heart transplant of genetically modified pigs in humans. This is the second patient in the world to undergo the innovative xenotransplantation technique (transplant between different species).
The operation was carried out on Wednesday 20th. According to the university, the patient is now breathing independently and his heart is functioning well without the assistance of assistive devices. The treatment uses a new antibody therapy along with traditional antirejection medications to prevent the patient’s immune system from attacking the organ.
David Bennett, 57, the first patient to receive a pig’s heart, survived for about two months, a fact that was widely celebrated by the global scientific community. To give you an idea, the first person to undergo a conventional (humantohuman) heart transplant in 1967 lived just 18 days today, after improvements, the technique saves thousands of lives, including that of the Brazilian presenter Faustao.
In the nearly two years since the first operation, scientists have investigated the causes of Bennett’s death. They believe his death from heart failure was likely caused by “a number of factors”, including his poor health before the transplant, which led to him being on a machine in hospital for six weeks before the procedure.
Lawrence and Ann Faucette before the procedure Photo: Tom Jemski/UMSOM/Reproduction
The new patient, 58yearold Lawrence Faucette, with endstage heart disease, was ineligible for a traditional transplant. Therefore, the Food and Drug Administration (FDA), an American agency similar to Anvisa, granted emergency authorization for the operation.
“My only real hope is the pig’s heart. At least now I have hope and a chance,” said Faucette, a Marine veteran and father of two. “My family was great, so I will fight with all my might to stay with them longer.”
His wife, Ann Faucette, agrees. Their only expectation, he says, is more time together, even if that just means the opportunity to drink coffee together on the porch. “Just the simple things we don’t think about when everything is going well.”
Since the 1960s, experts have been studying the possibility of transplantation between different species. In the 1980s it was realized that pigs were the best option. Because they are easy to handle and physiologically and anatomically similar to humans.
However, transplantation of an ordinary pig results in hyperacute rejection (reaction of the human immune system), which requires immediate explantation (removal of the organ). Scientists therefore devoted themselves to genetically modifying these animals until around 2005. Rejection is also a problem in humantohuman transplants but not to this extent.
Another patient receives a genetically modified pig heart. Photo: Tom Jemski/UMSOM/Reproduction
Gene editing involves gene knockouts (blocks) and knockins (additions). The scientist takes cells from newborn pigs, blocks the genes responsible for producing the sugar that triggers rejection, and inserts human genes to moderate the patient’s immune response. The modified cell is introduced into an egg cell without a nucleus (without genetic material). While not cloning, it uses a nuclear transfer technique learned from Dolly the sheep.
Why do we need organs from other species?
In the search for “extra organs,” there is a caveat to homologous transplants: There are not enough organs for those who need them, and thousands are dying on waiting lists — which is expected to increase as the population ages.
In addition, xenotransplantations open up a number of unprecedented privileges. From better predictability of the procedure, which would result in lower costs, to the possibility of the patient having a “pig brother” that would help control rejection, such as: Estadão showed in a report published last year.
Other techniques are aimed at solving the problem of organ deficiency. This includes cryopreservation, a field that studies the possibility of bringing systems and organs back to life after freezing. This is about preserving organs. Many are exhausted because they cannot stay outside the body for long.
For the first time, Scientists at the University of Minnesota (USA) managed to carry out “frozen” kidney transplants (cryopreservation) in five mice a still small group. Using the innovative and experimental technology, they stored the organs for up to 100 days.