UCLA Journal of Radiation Oncology January 1, 2022 - Flipbook - Page 7
UCLA RADIATION ONCOLOGY JOURNAL
Groundbreaking science and crossspecialty collaboration enable
transplant recipients to thrive without
immunosuppressive drugs
Teaching the body to tolerate
transplanted organs
The tolerance approach calls for blending
the donor’s and recipient’s immune systems
through an infusion of the organ donor’s stem
cells shortly after the organ transplant. Called
“mixed chimerism,” this blending prompts the
recipient’s body to recognize, rather than reject,
the new organ.
W
hen he was a medical trainee, UCLA
Health nephrologist Erik Lum,
MD, was part of a team at Stanford
University exploring how to create “tolerance”
in kidney-transplant patients — a process that
encourages the body to welcome the new organ
without the necessity for a lifelong regimen of
anti-rejection drugs.
“If you have introduced both the donor’s stem
cells and kidney, then the recipient’s immune
system recognizes that kidney as self,” says
Jeffrey Veale, MD, who specializes in renal
transplantation and was instrumental in
developing the new tolerance protocol at UCLA
Health.
Now, Dr. Lum is among the leaders of a
multidisciplinary team making transplant
tolerance a reality at UCLA Health. Two kidney
transplants have been performed thus far under
the advanced protocol, making UCLA Health one
of only five medical centers in the world capable
of the groundbreaking approach hailed as “the
Holy Grail” of transplantation.
The science that led to the development of
organ-transplant tolerance approach has been
evolving for decades.
"The recipient's immune system recognizes that
kidney as self" -Jeffrey Veale, MD
“It requires a lot of interplay between different
divisions,” Dr. Lum says. “To me, it really
demonstrates the strength of a place like UCLA.
You can’t do this just anywhere. It’s a huge
collaboration.”
Solid-organ transplants have been successfully
performed since the 1950s, but they always
have required powerful medications to
prevent the recipient from rejecting the new
organ. In addition to being expensive, these
immunosuppressive drugs also carry with them
a number of serious potential complications,
including increased risk of cancer, infection,
diabetes, hypertension and heart disease, and
they must be carefully managed throughout the
patient’s life.
The protocol, made possible by funding
provided by the OneLegacy Foundation, brings
together a broad range of specialties, including
nephrology, urology, hematology, radiation
oncology and others, for a series of treatments
that prime the transplant recipient’s body to
accept the new organ.
With traditional transplants, the body recognizes
the new organ as a foreign invader, prompting
the immune system to attack. A regimen of
immunosuppressive anti-rejection drugs tamps
down this natural response. The drugs, which
themselves carry potentially significant risks,
remain necessary throughout the patient’s life
because the body continues to see the organ as
foreign.
Because these powerful medicines are filtered
through the kidneys — the very kidney that has
been transplanted — they eventually overwhelm
and overtax the new organ. A goal of the
tolerance approach is to extend the survival of
the transplanted kidney.
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