A pig’s heart beats inside a human!
No lie this, but an American had the first-ever transplant from a gene-edited pig, enlivening hopes for thousands across the world
Domestic animals have often been known to save humans from danger. But now, it seems undomesticated animals can turn into human life savers, too.
David Bennett Sr., a 57-year-old man — who had no option left to live but to have a transgenic pig heart transplanted in him — is now being hailed as a truly giant leap for medical sciences. The kind that may have made even Neil Armstrong proud!
While one might still find the tale of a pig heart beating inside a human’s chest merely science fiction, the truth does get, as they say, stranger than fiction.
Going back as recently as October 2021, surgeons in the USA had undertaken a kidney transplant in a brain-dead patient using the kidney from a genetically modified pig. Even that seems to be working without problems.
So, could such experiments, using animals as life savers for humans, be the future of medical science? Could this pave the way for more animals being used to save humans? How do experts feel about this unique man–animal relationship?
ALL ABOUT THE TRANSPLANTATION
The pig-heart transplant was achieved by Dr Bartley P. Griffith, a leading cardiothoracic surgeon, and his team at the University Of Maryland Medical Center, Baltimore, USA. Indeed, the team
was cleared for all legal approvals. The modified pig was supplied by Revivicor, a company in
WHY PIGS? HERE’S WHY (AND WHY NOT)
It was in the early 1990s that pigs were considered possible organ donors for humans instead of primates. Here’s why:
Pig’s organs are anatomically closer to human organs and they come in all sizes
They’re easy to breed and can grow in six months
They’re suitable for genetic engineering Millions of pigs are slaughtered annually for human consumption and this should not pose any objection from the society
Unlike primates, pigs aren’t endangered species
Blackburg, Virginia, USA, working on regenerative medicine.
Dr Alla Gopala Krishna Gokhale,
BUT THERE ARE ISSUES TOO. AND HERE ARE SOME OF THE KEY ISSUES:
“The key problem with pig organs is that they elicit strong immune responses due to certain antigens, especially by an epitomegal-epitome,” says Dr Alla Gopala Krishna Gokhale.
This can cause immediate rejection of the organ by the antibodies present in human blood. However, medical teams are presently deleting the gene responsible for this epitome and other immunogenic epitomes and adding other genes from the human genome to make it seem closer to human antigens.
This is still in an experimental stage though we may soon electively fix a day and time for the transplantation of these pigs’ hearts and kidneys.
We need to also solve other issues like transmitting of viruses, especially porcine endogenous retrovirus (PERV), before the transplantation becomes a clinical practice.
cardiothoracic and transplant surgeon, Apollo Hospitals, explains to us that while four pig genes were knocked out to avoid antibody mediated rejection, six human genes were inserted to promote the immune acceptance. And while the patient was taken off the ventilator, Dr Gokhale observes that we still have to wait for further progress. “If patient survives longterm, this can be a big boon to thousands of patients waiting all over the world for cadaveric heart transplantation,” he adds.
XENOTRANSPLANTATION, THE GAME CHANGER
Xenotransplantation, the process of grafting or transplanting organs or tissues from animals to humans, has a long history. Efforts to use the blood and skin of animals go back hundreds of years. This is especially workable for humans as the pig anatomy is known to be exactly similar to that of the humans.
Dr Jnanesh Thacker, Senior Cardiothoracic, Heart and Lung Transplant Surgeon, Yashoda Hospitals, confirms.
“The pig’s heart is exactly like the human heart, the only difference being that the inter-atrial and inter-ventricular septum are more vertical in the pig and the heart is more centrally located in its chest unlike in the human being, where it’s deviated slightly to the left,” states Dr Thacker. “A young, fully grown pig’s heart can easily support human circulation.”
POTENTIAL ADVANTAGES AND PROBLEMS
As of now, millions of people are registered for organ transplantation, including kidney, liver, heart, lungs and cornea, with a large proportion of those dying due to the lack of availability of organs.
However, this recent leap in medical sciences is not without questions.
For instance, Dr Gokhale informs us that while the transplantation of some organs like that of the kidney and liver ca be done using live donors, oth ers like the heart necessaril need brain-dead donors.
“One of the options scientist have considered is the possibil ty of transplanting organs an tissues from different species adds Dr Gokhale and then cau tions. “In the 1970s and 1990 attempts were made to tran plant kidneys, livers and some times hearts from nonhuma primates to humans. But majority of them failed ver early due to rejection, infectio or surgical complications.”