The heart of a baboon, the eye of a newt, and the skin of a pig, is not just a recipe
for witchcraft anymore.
Some might be part of the future of organ transplantation.
Hey everyone welcome to DNews, I'm Trace.
For more than two years, a baboon at a research institute in Maryland survived with the heart
of a pig in its abdomen!
Two.
YEARS.
The previous record for implanting an organ from another species was about 500 days, but
this heart made it to 945 days!
Cross-species transplantation is called xenotransplantation.
It might seem like a Frankensteinian fiction, but it's been done.
A baboon heart was transplanted into a newborn baby with a heart problem (she lived almost
three weeks), burn patients sometimes accept skin grafts from pigs, and Parkinson's patients
have received neurons from our p-p-p-porky pals as well.
It would seem we have an unending supply of organs from animals grown for food, but cross-species
transplants -- though hypothesized for centuries, are JUST becoming a reality… if scientists
can get it to work properly…
Firstly, we needed to pick a species.
The natural inclination may be to use genetically related primates, like chimpanzees!
But, chimps are endangered…
Baboons on the other hand, are genetically similar to chimps and humans, and are relatively
plentiful!
But, they're terrible transplant donors!
Their organs are too small and matching our blood types is incredibly rare.
In fact, throughout history doctors have been pretty slapdash at picking animals, trying
sheep, rabbits, dogs, cats, rats, chickens… even pigeons!!
It turns out pigs might be one of the best.
Despite having little genetic commonality, pigs bodies and organs are almost identical
in form and function to a human’s!
The heart, specifically, is roughly the same size and shape.
Because of this, we already use pig valves in some heart repair!
Additionally, pigs are plentiful, and society has no real qualms about killing them -- even
if some people do.
Okay, so we've got our pig, now what?
Well, any time a foreign object enters your body, your immune system mounts a defense
to wipe out the intruder If someone just jams a new heart in you, your body will assume
that it is a giant virus or some other invader and begin attacking it with a fervor.
There are two ways to stop this, one: immunosuppressant drugs -- literally shut down the immune system;
obviously not ideal…
OR you can trick the immune system into thinking the new organ was part of the body the whole
time.
Simply put, most tissues have proteins on their surface called Human Leukocyte Antigens.
They're like license plates, telling your immune system which tissues are local.
If researchers can take the plates off the new organ (or match them) the immune system
will leave it be.
In this case, doctors implanted the pig heart into the baboon's abdomen and used drugs to
suppressed the immune system.
But, there's another concern!
Pigs, unlike humans, have ANOTHER antigen called galactose oligosaccharide -- or just
Gal.
In the 90s, researchers realized because humans don't make Gal our immune systems goes crazy
when it sees it.
It's like seeing a license plate from Nazi Germany in Cleveland.
The organ can be rejected in MINUTES.
In 2007, cloning technology finally resulted in a gal knockout pig!
Basically, a pig without the gene to make the gal antigen.
This pig heart, was one of those genetically modified gal knockouts.
No antigen backlash!
945 days of hearty fun!
It might have gone longer, but the heart began to degrade as the immunosuppressants were
relieved.
This is a really exciting test, because if the pig heart can survive and pump blood in
a close human relative even for a short time; it might open the doors for pig parts to become
'bridge organs' for those waiting for a human ones.
22 patients die everyday waiting for donor organs!
Broadening the field of potential donors could save thousands of people.
Obviously, the ability to keep the body from rejecting any foreign organ is amazing…
But to use one from another species is just insanely medievally cool.
Plenty more research still needs to be done, but still, can you imagine walking around
with a pig heart?!
Wow.
I wonder if I'd become more delicious.
MMMMmmm.
Look if you're into weird transplants, then you should definitely check out Julian's video
about how doctors are transplanting penises.
Julian totally went there.
OR, if you want to know more about how we swap out antigen license plates to help organs
work in new people,: Amy's got that for you, right here.
Let's say you needed an organ… would you take a pig heart?
Do you have qualms?
Tell me about it.