Global Health Asia-Pacific September 2020 September 2020 | Page 35
Pigs might help people in need of a new lung
Using the animals as bioreactors might turn damaged organs into viable grafts
Connecting donated lungs unsuitable for
transplantation to a pig allowed them to achieve
functional improvements, thus promising to expand the
limited pool of healthy organs that can be grafted.
As about �0 percent of the explanted human lungs
can’t be transplanted due to injury, they are typically
hooked up to machines that supply them with oxygen
and nutrients in the hope of improving their functions
and making them viable for transplantation. �ut this
process can only keep the organs alive for six hours, a
length of time that often doesn’t lead them to recover.
As a result, many patients with lung disease die
while waiting to receive a suitable graft.
A team led by Dr Matthew �acchetta of Vanderbilt
University and �rofessor �ordana Vunjak-�ovakovic
of Columbia University managed to keep five lungs
alive for 24 hours by linking them to the circulatory
system of a pig, and one of them healed to the point
that it met the criteria for transplantation but wasn’t
actually grafted on to a patient. All the five lungs were
previously supported with standard machines but
didn’t recover.
�If there were a way to maintain organs in a healthy
state outside the body for a day or several days, then
many things would change in transplantation,� Dr
�obert �artlett, a researcher in organ transplantation
at the University of Michigan who was not involved in
the experiment, told STAT. ��ou could have perfect
matching. �ou could treat organs injured outside the
body until they’re working well. So that’s what Dr
�acchetta and his crew are working on. And they’re
doing a marvelous job.�
Dr �acchetta believes the improvements are due
to the fact that pigs act as a bioreactor performing a
variety of functions. �All of a sudden, �the lungs are�
attached to a functioning liver, a functioning gut. We
don’t have to worry about glucose regulation because
there’s a pancreas,� he told STAT.
This healing process, he added, is carried out by
�magic molecules� in the pigs’ blood, raising hopes that
the same results could be obtained in the clinic without
using an actual animal. �Once we know why it works,
we’ll really be able to isolate those molecules and
achieve the same thing. �rom work in our laboratory
and others, we think that this will be possible within a
couple of years,� he said.
�efore using this technique in the clinic, however,
future studies will have to establish its safety, feasibility
and outcomes in a greater number of lungs, the authors
of the experiment wrote in Nature Medicine. They
envision critically ill patients who urgently need a lung
transplant but can’t find a suitable donor as potentially
good candidates for the procedure because for many
of them this could be the only shot at a life-saving
operation.
They also believe modified versions of the technique
they developed might help recover other human organs,
including hearts, livers, kidneys, and limbs.
The healing
process is
carried out
by “magic
molecules”
in the pigs’
blood, raising
hopes that the
same results
could be
obtained in the
clinic without
using an actual
animal.
GlobalHealthAsiaPacific.com
SEPTEMBER-OCTOBER 2020
33