A new variation in kidney paired donation —
pioneered and developed at Johns Hopkins — could
theoretically generate an endless number of transplants,
researchers report.
The possibility of sparking "daisy chain" transplants,
described in the March 12 issue of The
New England Journal of Medicine, was prompted by
reports of one round of 10 kidney transplants, all
generated from a single kidney donated by an altruistic
donor, said Robert Montgomery,
transplant
chief at the Johns Hopkins University School of Medicine
and senior author of the study. An altruistic
donor is someone willing to donate a kidney to any needy
recipient.
What the authors dubbed as nonsimultaneous, extended,
altruistic donor chain, or NEAD, begins
with a kidney from an altruistic donor that is compatible
and transplantable in a patient who has a
relative or friend willing to donate but whose kidney is
not compatible by blood or tissue type. Once
the altruistic donor kidney is matched up and transplanted,
the kidney from the willing donor from the
original incompatible pair goes to solve the problem of
another incompatible donor-recipient pair and
so on, theoretically endlessly, limited only by the number
of recipients and possible, available matches.
The 10-way NEAD or "daisy chain" outlined in the NEJM
article started at an Arizona hospital
in July 2007. The majority of the subsequent transplants,
including the most recent, 10th transplant
in the chain, were performed at The Johns Hopkins
Hospital.
NEAD builds on the concept of so-called domino kidney
paired donation. Developed and
pioneered at Johns Hopkins, domino KPD uses a kidney from
an altruistic donor that goes into a pool
that includes a finite number of incompatible
donor-recipient pairs and a patient that's next on the
United Network for Organ Sharing recipient list. Doctors
and transplant coordinators can then match
donors with recipients inside this pool, striving for the
best possible match based on blood and tissue
antigen testing. Although effective, this process is
limited by the number of available incompatible
pairs, good matches and available operating rooms because
all the surgeries are performed on the
same day.
"When an altruistic donor starts a kidney donation
chain, it is no longer imperative that the
transplants are done simultaneously," said Michael A. Rees,
lead author of the study and medical
director of the Alliance for Paired Donation, a consortium
of transplant centers that maintains a
database of incompatible donor-recipient pairs.
This is beneficial because the procedure does not
require multiple surgeons and operating
rooms. It also eases the complicated matching required when
there are multiple donors and recipients
needing same-day surgery.
"NEAD chains are the latest of a series of important
breakthroughs in transplantation that will
significantly increase the number of life-saving organs
available to hard-to-match patients, many of
whom die while waiting years for a kidney," Montgomery
said.
Johns Hopkins surgeons performed one of the first KPD
transplants in the United States, in
2001; the first triple-swap, in 2003; the first double and
triple domino transplant, in 2005; the first
five-way domino transplant, in 2006; and the first six-way
domino transplant, in 2007. Johns Hopkins
also led the first multihospital, transcontinental
three-way swap transplant, in 2007.
GO TO