Yale: Kidneys from deceased donors that have acute injuries are frequently
discarded instead of being used for transplant. However, a Yale-led
study finds that such kidneys may be more viable than previously
thought, and should be considered to meet the growing demand for organ
transplants.
Donated kidneys with acute injury are often discarded
for fear of poor outcomes such as delayed function and even premature
kidney transplant failure. Given the growing need for transplant organs,
the Yale-led team embarked on the largest multicenter observational
study of its kind to date, including more than 1,600 deceased donors.
They examined associations between acute kidney injury (AKI) in donors,
rates of kidney discard, and recipient kidney function in the short term
as well as six months after transplantation.
As anticipated, the
researchers found an association between AKI and organ discard. They
also found that injured kidneys were associated with “delayed graft
function (DGF),” or the need for continued dialysis support in the first
week after transplantation. But unexpectedly, the study did not find a
link between deceased-donor kidney injury and poor kidney transplant
function six months later.
“What we saw was, with worsening AKI in
the donor, the six-month outcome was actually better for recipients who
experienced DGF,” said Dr. Isaac E. Hall,
investigator in the Program of Applied Translational Research at Yale
School of Medicine and first author of the study. Paradoxically,
six-month transplant function was worst for those with DGF who had
received a donated kidney with no apparent injury.
Though that
result seemed counterintuitive, Hall suggested that organs acutely
injured in the donor might develop “ischemic preconditioning,” a
mechanism that could protect the organs from the effects of subsequent
injury. Another possible explanation is that the successfully
transplanted kidneys with AKI were of otherwise higher quality than the
rejected kidneys with AKI, though the study did adjust for many
important variables like donor age and comorbidity.
“There appears to be room to attempt more transplants using these AKI kidneys rather than throwing them away,” said Dr. Chirag R. Parikh, director of the Program of Applied Translational Research and senior author of the study.
“The
waiting list has grown to over 100,000 patients as thousands more
people are wait-listed each year than actually receive a transplant. In
addition, the median time it takes for an adult to receive a transplant
in the United States increased from 2.7 to 4.2 years between 1998 and
2008, and more than 5,000 people die each year while waiting for a
kidney,” said Parikh.
“Even if it only means a few dozen more
kidney transplants each year, those are patients who would come off of
the waiting list for transplants sooner and have much better survival
than continuing on dialysis in hopes of seemingly higher-quality kidney
offers, which may never come in time,” he said.
The study was published March 11 in the American Journal of Transplantation.
Other
authors include Bernd Shröppel, Mona D. Doshi, Joseph Ficek, Francis L.
Weng, Rick D. Hasz, Heather Thiessen-Philbrook, and Peter P. Reese.
This
work was supported in part by the American Heart Association and the
National Institutes of Health grant RO1DK-93770, grant K24DK090203.
Citation: American Journal of Transplantation