Newswise — A simple, 10-minute bedside assessment conducted prior to surgery
appears to be the best method yet for predicting which kidney transplant
patients will do well with their new organs, new Johns Hopkins research
suggests.
A report on the research, published in the February issue of
the Archives of Surgery, suggests that a recently developed test of frailty,
typically used to assess the physiologic reserve of elderly patients, is also a
useful measure for transplant candidates of all ages.
“Few current
measures are accurate in predicting kidney transplant success, but we think we
have identified one that works incredibly well,” says study leader Dorry L.
Segev, M.D., Ph.D., an associate professor of surgery at the Johns Hopkins
University School of Medicine. “A few years ago, we showed that a frailty score
is a simple, yet powerful, bedside tool to predict surgical outcomes in elderly
patients and now it seems it can do that same for younger patients with chronic
diseases like kidney failure.”
Frailty, Segev says, is best defined
medically as a low level of physiologic reserve and reduced ability to withstand
stress to the body. It is measured using a five-point scale developed at Johns
Hopkins. A patient is classified as frail if they meet three or more of the
following criteria: shrinking (unintentional weight loss of 10 or more pounds in
the previous year); weakness (decreased grip strength as measured by a hand-held
dynamometer); exhaustion (measured by responses to questions about effort and
motivation); reduced physical activity (determined by asking about leisure time
and activities); and slowed walking speed (the time it takes to walk 15
feet).
For the current study, Segev and his team measured frailty in 183
patients prior to kidney transplant between December, 2008, and April, 2010.
Twenty-five percent of the transplant patients met the criteria for frailty, a
figure three times higher than in elderly adults who live at home. Kidney
transplant patients classified as frail were nearly twice as likely to have
early problems with their new organs, a sign that their new kidneys would be
more likely to fail in the future. This increased risk of a poor outcome, Segev
says, occurred regardless of the age of the transplant recipient. Segev and his
team used the short-term outcome of delayed graft function (DGF) — meaning a
non-functioning organ within the first week after transplant — as a marker for
risk of longer term concerns. Although the transplanted kidney may recover and
work eventually, he says, it is unlikely to work for as long as a kidney that
begins working more quickly in its new body. Researchers found delayed graft
function in 30 percent of the patients deemed frail and in just 15 percent of
those who were not.
“This information tells us how long the kidney will
likely last and how to best treat the patient,” he says. “Our ability to predict
delayed function of a new kidney should help overcome one of the biggest
barriers to improving outcomes in transplant right now.”
Segev, who is
Johns Hopkins’ director of clinical research for transplant surgery, says
accurate predictions can help guide clinical decisions, such as ensuring frail
patients receive organs at least risk of DGF. For example, the risk of DGF
increases when a kidney spends longer a longer time outside the body on its way
from donor to recipient. Segev says a kidney coming from across the country
might not be the best kidney for a frail patient, since it would less likely to
function quickly and thereby more likely to have problems down the
road.
The link between frailty and chronic kidney disease may be found in
certain markers typically associated with inflammation, Segev says. As some
people age, such genes and proteins may be expressed at higher levels. Frailty,
typically found in at least some measure in the elderly, appears to occur in
younger kidney patients undergoing dialysis as well. Those who are classified as
more frail, young or old, seem to also have a risk of developing inflammation in
the new transplanted kidney, which can lead to poor outcomes.
“We have
found similarities between what makes people age and what makes dialysis
patients sick,” Segev says. “But what makes people frail in the first place and
what part of frailty affects the kidneys are the questions we have yet to
answer.”
This research was supported by a Clinical Scientist Development
Award from the Doris Duke Charitable Foundation.
Other Johns Hopkins
researchers involved in the study are Jacqueline M. Garonzik Wang, M.D.;
Priyanka Govindan, M.D.; Jack W. Grinnan; Minghao Liu; Hassan M. Ali; Anindita
Chakraborty; Vaibhav Jain; Reside L. Ros, Sc.M.; Nathan T. James, Sc.M.; Lauren
M. Kucirka, Sc.M; Erin C. Hall, M.D., M.P.H.; Jonathan C. Berger, M.D., M.H.S.;
Robert A. Montgomery, M.D., D.Phil.; Niraj M. Desai, M.D.; Nabil N. Dagher,
M.D.; and Jeremy D. Walston, M.D.
This article was first published at www.newswise.com.