- [Narrator] In the first successful surgery of its kind
a 57 year old man received a heart transplant
from a genetically modified pig.
It's not the first time researchers have used pigs organs.
In fact, pig valves have been used in human hearts
for many years.
In September 2021, surgeons at a different institution
successfully attached pig kidneys to a brain dead patient.
Why pigs?
- They're many good reasons we've selected the pig
as the potential source of those organs
mainly because of the size, the ease of maintaining them
inside a clean pig facility, the reproductive capacity,
the organs are very similar anatomically
and physiologically to humans.
- [Narrator] This kind of animal to human surgery
known as xenotransplantation
is the result of decades of research.
Even in human to human transplants without proper treatment
the body will reject the new organ.
The immune system identifies the transplanted organ
is foreign and targets it with killer T cells
and antibodies made by B cells.
Over time, these damage the organ
and may cause organ failure.
To prevent this transplant patients take medication
that suppresses their immune systems.
In the recent case using a pig's heart
not only did the recipient take a new kind
of immunosuppressive medication
but the organ supplier was genetically modified
for a better chance of acceptance by the human body.
- The treatment we used to prevent rejection to human organ
is not very effective against preventing rejection
of a pig organ.
So we're using some new immunosuppressive drugs.
It's the first time in transplantation we've had
the opportunity to manipulate the donor rather
than just suppress the recipient
- [Narrator] Scientists modified 10 genes.
They inactivated four genes including one that causes
a strong rejection response in humans.
And added six human genes to the pigs genome
to make its organs more likely to be accepted
by the human immune system.
Researchers are hoping that modified pig organs
could bring relief to people on the waitlist.
Today, many never get the chance to have an operation.
Of the over 100,000 people on the United States
and counting, 17 people die every day waiting
for these lifesaving surgeries.
- Even if we did 40,000 transplants this last year
there're still new patients added to the list every year.
There's always an organ shortage
so not everybody will be a candidate for transplants.
- [Narrator] So who does get the few available organs?
To receive any kind of transplant, animal or human
patients must meet certain criteria.
- [Juan] Every patient will have a similar kind of checklist
to make sure that they're good candidates for transplant.
Does the patient has caregiver support
or are they complying with medications
do they show up to their appointments?
Can they afford the medications?
- [Narrator] Ideally, everyone would have equal access
to these life saving treatments
but that's not always the case.
- [Keisha] Who is having access to organs
and is the access equitable?
Black people, Latinx people and Indigenous people
are less often referred to organ transplantation.
They're also less often recipients of organ transplant.
And so what we really wanna make sure
is that we don't limit who has access to this kind of care,
this kind of life altering care
- [Narrator] But do you know transplantation still has
a long way to go before it's considered life altering care?
The recent surgeries were highly experimental
a last resort for dying or brain dead patients.
And we don't know how long the transplanted pigs heart
will continue to function.
- [Keisha} People who are open to xenotransplantation
are usually at the end of their life
they usually have been given some diagnosis that is terminal
or maybe they are not eligible for a human organ.
And so if they are open as you know transplantation
we really have to think about are we praying on people
who are very desperate?
who will do anything to survive?
- [Narrator] The next step for xenotransplantation
is to study the heart and kidney transplants
in the context of clinical trials
- [Keisha] Xenotransplantation right now
still needs to be studied a lot more
we still need a lot more clinical trials,
we still need just a lot more information
about its success among humans.
And so what I wanna make sure
is that we don't start promoting xenotransplantation
without a proper research and giving people hope
where maybe it's giving them false hope.
(gentle music)