NEW
UNOS STANDARDS FOR KIDNEY ALLOCATION:
DO
THEY DISCRIMINATE AGAINST THE OLDER PATIENT?
BY
JAMES MYERS
A while back, I was sitting in my kidney transplant
surgeons’ office at the University of Wisconsin, discussing kidney
transplantation. He drew 4 boxes on a
sheet of paper. Pointing from left to
right, he said, “These boxes represent age divisions of potential donors from
the youngest group to the oldest.” Then he drew an X through the far left- side
box. “Under the new rules, you will be
no longer be eligible to receive a cadaver kidney from this group.” This was my first exposure to the new UNOS
kidney allocation rules that come into effect December 4, 2014.[i] It is my belief that the new rules
discriminate against the more mature kidney patient.
According to UNOS, the new rules, are designed to create a
significant increase in the life years of transplants. [ii] To do this, UNOS has
designed a kidney allocation plan that, “would give more kidneys to younger,
healthier patients in an effort to achieve greater survival time from each
transplant.[iii]” It is my contention that the new standards
favor the younger kidney patient and discriminate against the older kidney
patient. [iv]
The key to all of this is that UNOS has moved from a
waiting time allocation standard to a risk quantification score; how long will
the kidney last and how long will the recipient last. The longer lasting
kidneys will go to the longer lasting recipients.[v] In the eyes of UNOS, the current standards do
not account for kidney longevity; will the person who receives a cadaver kidney
live as long as the kidney is expected to last?[vi] The new system was
allegedly put into place to alleviate this issue and in affect to make certain
that people with longer life expectancies (younger persons) receive kidneys
with a like longer life expectancies.[vii] According to UNOS, 80% of us will be
unaffected by the new kidney allocation rules[viii], and the rules have no
effect over living donor donation or paired matched donation. [ix]
“The new system outlined by UNOS' Kidney
Transplantation Committee would give the highest-quality kidneys to the 20% of
recipients with the longest estimated post-transplant survival time. The other
80% of kidneys would be matched roughly by age, with recipients 15 years older
or younger than the age of the deceased donor getting the highest priority.[x]”
The key to the new rules is that the effect the new kidney
allocation rules have on the patient is based on his clinical circumstances.
“"The No. 1 reason we lose a kidney
transplant is that the patient dies with a kidney working," said Dr.
Formica, a nephrologist. "We'd like
for that to happen less often. If you have a kidney from an 18-year-old donor
that is likely to last, say, 12 years, it would be much better to have that
kidney in a 30-year-old and have that 30-year-old get the maximal life expected
from that kidney than have that kidney in a 75-year-old where the person would
likely die only having used five years of the expected life of that kidney.
We'd rather take the kidney expected to last six years and give it to the 75-year-old.[xi]"
The new system has been justified by the following
statistics:
“The proportion of kidneys going to
younger recipients has fallen steadily since 1990, while the percentage going
to older patients has risen. In 1990, for example, 30% of kidneys went to
recipients between ages 18 and 34 and 23% went to adults 50 to 64, according to
the committee's paper. By 2009, just 13% of kidneys went to patients 18 to 34
years-old while 39% went to those between 50 and 64.
The life span of patients after receiving
a kidney transplant has fallen by 18 months since 1995, according to estimates
published March 16 in The New England Journal of Medicine by researchers at the
University of Michigan Medical School and the Arbor Research Collaborative for
Health, both in Ann Arbor, Mich.[xii]”
Some
professionals are not so sure:
“The
new approach would hurt older patients, said Lainie Friedman Ross, MD, PhD,
associate director of the University of Chicago MacLean Center for Clinical
Medical Ethics. “One of my big concerns is given how it's structured, most
kidneys go to younger people," Dr. Ross said. "I would argue that
it's discrimination against people who are older. If the allocation plan were
changed, more than 1,100 kidneys would go to patients 50 and younger instead of
going to people older than 50, the committee estimates.[xiii] “
Dr.
Ross said she does not trust the simulations used by the committee to estimate
the effect of potential changes because they were done on a national basis,
whereas kidney allocation takes place on a regional basis and varies widely,
depending on the number of candidates and donors in an area. She said the committee did not take into
account the potential effect of changes on living donors. If younger patients
have greater and faster access to deceased donor kidneys, they may be less
likely to ask loved ones to donate to them -- decreasing the total number of
kidneys available to transplant.[xiv]
EARLY
REFERRAL FOR A TRANSPLANT
WHEN
IS THE BEST TIME TO BE REFERRED FOR A TRANSPLANT?
The
new rules also change the basic philosophy on when is the best time to be
referred for a transplant. Under the new
rules, the goals is that every patient be referred as soon as possible.[xv] Patients can now be placed on the list before
they start dialysis.[xvi]
While
waiting time is now being calculated to include pre-registration dialysis time,
the GFR value criteria remains the same and patients can accrue waiting time
points based on this criteria alone.[xvii]
In
addition, the new allocation system continues to prioritize for zero antigen
mismatches, which often do not require significant waiting time in order to
receive these offers.[xviii]
WAITING TIME-HOW LONG WILL A KIDNEY PATIENT WAIT FOR A
TRANSPLANT
While waiting time is still a factor in receiving a kidney,
there is some good news here. First,
patients will receive time credits for time waiting before dialysis.[xix] Second, your wait time will be wound back to
the actual date you started dialysis.[xx] This has been done because 85% of patients
currently have less than 3 years of pre-transplant time, while only 7% of the
patients have than 5 years.[xxi] For adults, the waiting time starts when
registered or date of first dialysis or GFR or CRCL is = or < 20 ml/min.
The bottom line is in the new system, waiting
time priority will remain a key factor in allocation.[xxii] Adults will be assigned waiting time points
for time on dialysis prior to registration, meaning that they receive a credit for
time spent on dialysis prior to listing. This recognizes that prioritization
for transplant is based on a patient’s medical need and time on dialysis is an
indication of time spent with ESRD.[xxiii]
However,
the policy that allows a patient to begin accruing waiting time points at/after
registration for a GFR value equal to or less than 20 remains unchanged. In
other words, patients will not receive backdated time for the GFR value
criteria.[xxiv]
For
pediatric patients, waiting time begins immediately at the time of
registration.[xxv]
THE IMPORTANCE OF THE KIDNEY DONOR PROFILE INDEX (KDPI)
The Kidney Donor Profile Index (KDPI) is a new
quantification system to determine the suitability of a particular kidney for a
particular patient.[xxvi] The old classifications for kidney
allocation, “standard criteria" or "expanded criteria", without
any distinction of donor kidneys within each group, have been discarded.[xxvii] Now ever kidney offered will have a KDPI
score.[xxviii] The key here is that
the KDPI results in a percentage. The
lower the percentage, the better the organ is, at least in terms of how long
they expect it to last. [xxix] The longer the kidney will
last is an indicator of to whom the kidney will go to. That kidney will go to the person who has the
longer corresponding life expectancy, i.e. the younger patient. [xxx] KDPI summarizes 10 donor
factors associated with the number of years a transplanted kidney is expected
to function including:
i.
Age
ii.
Height & Weight
iii.
Ethnicity
iv.
History Of HBP
v.
History Of Diabetes
vi.
Stroke As A Cause Of Death
vii.
Serum Creatine
viii.
Exposure Hepatitis C Virus
ix.
Death Due To Loss Of Heart Or Brain
Function
So
what is considered a good score? The
KDPI ranges from 0-100%.[xxxi] A lower score suggests the kidney will last
longer, have a longer function time, while a higher KDPI score suggests a
lower, lessor function time.[xxxii] For example, a kidney
with a 0-20% score is expected to last 11.5 years after a transplant; a kidney
with a 21-85% score will last over 5 years, while a score of over 85% lasts 5 ½
years.[xxxiii]
The
pitch we’re getting from UNOS here is that if you are willing to accept a
kidney with a KDPI score of over 85%, you may get your kidney sooner.[xxxiv] This to me on its
face, appears to be a way to move older patients off of the list. Although there is always a chance the >85%
may last more than 5 years, it still seems relatively short to me, and maybe a
ticket back to dialysis. There is a
chart to help you determine the amount of time you can expect a kidney to last
that matches your KDPI[xxxv]:
What
this means is that is you have a KDPI of 82%, the donor organs has a failure
rate that is 82% higher than other donor kidneys.
WHAT IS THE DIFFERENCE FOR PEDIATRIC PATIENTS?
Pediatric
patients under the age of 18 will maintain their current access to kidneys but
will receive priority donors with KDPI of less than 35% instead of donors age
35 in the current system.[xxxvi] The emphasis is clearly on the longer lasting
kidneys to the longer lasting patients. There are other patient specific factors
than KDPI that are taken into account.[xxxvii]
ESTIMATED POST TRANSPLANT SURVIVAL SCORE (EPTS)
The
Estimated Post Transplant Survival Score (EPTS) also plays a role in the new
kidney allocation. The EPTS refers to
your expected post-transplant survival rate as a patient. [xxxviii] The EPTS score is
specific to each patient.[xxxix] Factors include:
i.
Age
ii.
Time On Dialysis
iii.
Current Diagnosis Of Diabetes
iv.
Prior Organ Transplant (Heart, Kidney,
Liver, Pancreas, Etc.[xl]
Again,
it is a score that ranges from 0-100%.[xli] Every adult candidate registered for a
transplant, will now receive an EPTS score.[xlii] An EPTS score will be
calculated, but not used for a transplant candidate under the age of 18.[xliii] The groups of patients
are broken down into 2 groups for EPTS scores:
i.
Candidates with a score of 20% or less;
ii.
Candidates with a score of more than 20%
A
lower EPTS score means that you are expected to have more years of function
from the donor kidney compared to patients with higher EPTS scores.[xliv] A higher EPTS score means the patient is
expected to have less years of function needed. [xlv] If patient is in the
first group, he is likely to need a kidney longer; they are likely to need a
kidney longer than 80% of the people listed for a transplant.[xlvi] This gives them
increased priority for a kidney that is expected to function the longest.[xlvii] Patients registered before they start
dialysis are more likely to have an EPTS score under 20%.[xlviii]
If
the patient is in the 2d group, with an EPTS over 20%, say a score of 60%, they
are likely to need a kidney that lasts longer than 40% of other listed
patients.[xlix]
In general patients with lower EPTS scores tend to be younger in age[l], and those with diabetes
tend to have higher EPTS scores.[li] Patients who have had
prior transplants or been on dialysis for a number of years tend to have higher
EPTS scores.[lii]
Patients in the < 20% group therefore have a higher priority to receive the
longer lasting kidneys in the KDPI group.[liii] Patients in the >
20% group receive no distinguished status.[liv]
UNOS Simulation/Projections Under the New Standards
According
to the Journal of the American Association of Nephrology,[lv] when a simulation was
done to determine how kidneys would be allocated under the new policy, the
group found that with the new policy, candidates with a CPRA>20%, with blood
type B, and aged 18–49 years were more likely to undergo transplant, but
transplants declined in candidates aged 50–64 years (4.1% decline) and ≥65 years
(2.7% declined)[lvi].
Conclusion
In
my opinion, the new standards favor the younger kidney patient. I have questions. First, if we are implanting the best kidneys in
the youngest patients, are we still not looking at multiple potential
transplants in their lifetime? Second,
are we still not looking at multiple transplants in the lifetime of a more
mature patient? Third, is there an issue with compliance? You have to be religious about your
medications on a post-transplant course, are the younger patients or the more
mature patient more compliant in these circumstances? These are questions that remain to be seen
and can only be answered by experience.
One
last thing, I am not opposed to younger patients getting their opportunity for
transplant. I am concerned about the
potential effect on the mature patient.
I think some difficult choices lie ahead.
ENDNOTE
[i] Kidney
Allocation System (KAS), http://transplantpro.org/kidney-allocation-system/
(Accessed 2014).
[ii]
Video, The Kidney Allocation System, What Candidates Need to Know, http://vimeo.com/107481347 (Accessed
2014).
[iii]
O’Reilly, Kidney Transplant Plan
Would Give Preference to Younger Patients, http://www.amednews.com/article/20110328/profession/303289943/7/ (March 28, 2011); Neurology on Demand,
The New Kidney Allocation System, https://storify.com/nephondemand/the-new-kidney-transplant-allocation-system (Accessed 2014); Video, The Kidney
Allocation System, What Candidates Need to Know, http://vimeo.com/107481347 (Accessed
2014).
[iv]
O’Reilly, Kidney transplant plan
would give preference to younger patients, http://www.amednews.com/article/20110328/profession/303289943/7/ (March 28, 2011).
[v] Benjamin
E. Hippen, M.D., J. Richard Thistlethwaite, Jr., M.D., Ph.D., and Lainie
Friedman Ross, M.D., Ph.D., Risk, Prognosis, and Unintended Consequences in
Kidney Allocation (April 7, 2011). (“the proposal makes
clear that allocating top-quintile organs to
top-quintile candidates will come at the expense of the
overall opportunities for older candidates on the
waiting list to be offered a kidney from a deceased
donor.”)
[vi]
The New Kidney Transplant Allocation System, https://storify.com/nephondemand/the-new-kidney-transplant-allocation-system,
(Accessed 2014).
[vii]
O’Reilly, Kidney Transplant Plan
Would Give Preference to Younger Patients, http://www.amednews.com/article/20110328/profession/303289943/7/ (March 28, 2011); Neurology on Demand,
The New Kidney Allocation System, https://storify.com/nephondemand/the-new-kidney-transplant-allocation-system (Accessed 2014); Video, The Kidney
Allocation System, What Candidates Need to Know, http://vimeo.com/107481347 (Accessed
2014).
[viii]
Talking About Transplantation, Question And Answers for Kidney Transplant
Candidates About Kidney Allocation, http://www.unos.org/docs/Kidney_Brochure.pdf
(Accessed 2014).
[ix]
O’Reilly, Kidney Transplant Plan
Would Give Preference to Younger Patients, http://www.amednews.com/article/20110328/profession/303289943/7/ (March 28, 2011); Neurology on Demand,
The New Kidney Allocation System, https://storify.com/nephondemand/the-new-kidney-transplant-allocation-system (Accessed 2014); Video, The Kidney
Allocation System, What Candidates Need to Know, http://vimeo.com/107481347 (Accessed
2014).
[x]
O’Reilly, Kidney transplant plan
would give preference to younger patients, http://www.amednews.com/article/20110328/profession/303289943/7/ (March 28, 2011).
[xi]
Id.
[xii]
Id.
[xiii]
Id.
[xiv]
Id. See Also: Benjamin E. Hippen, M.D.,
J. Richard Thistlethwaite, Jr., M.D., Ph.D., and Lainie Friedman Ross, M.D.,
Ph.D., Risk, Prognosis, and Unintended Consequences in Kidney Allocation (April
7, 2011)(“ The intuitive appeal of a proposal to maximize the overall survival
of patients after kidney transplantation is obvious. However,
a significant change in allocation policy must be based
on good data and sound methods of data analysis. As Ware has pointed out, the
use of risk factors as prognostic tools for the purpose of prospective
individual risk stratification often yields disappointing results.2 This is
because much depends on how various risk factors in donors and recipients are
distributed across sample populations that do or do not have graft loss. If a
single
risk factor — or an elaborate combination of donor and
recipient factors such as those captured in the KDPI and EPTS score is
distributed substantially similarly in the population of patients whose grafts
survive and in the population of those who experience graft loss, then a model
that uses it to distinguish graft survival from early graft failure will have
low sensitivity in making predictions regarding individual donor kidneys (in
the
case of the KDPI) or individual candidates (in the case
of the EPTS score). Any attempt to increase
sensitivity in the model will yield an unacceptably
high frequency of false positives.3”)(“ To ensure a fair allocation system, the
goal of maximizing benefit must be balanced by concerns about equity (fair
opportunity
for everyone with end-stage renal disease). In the
absence of reliable and reproducible prognostic tools for estimating graft
survival, and without a clear understanding of the unintended consequences of a
substantial change in allocation policy on trends in living donation,
discussing what a fair allocation policy should look
like is putting the cart before the horse.”).
[xv]
Video, The Kidney Allocation System, What Candidates Need to Know, http://vimeo.com/107481347 (Accessed
2014).
[xvi]
Id.
[xvii]
Neurology on Demand, The New Kidney
Allocation System, https://storify.com/nephondemand/the-new-kidney-transplant-allocation-system (Accessed 2014).
[xix]
Video, The Kidney Allocation System, What Candidates Need to Know, http://vimeo.com/107481347 (Accessed
2014).
[xxi]
Id.
[xxii]
Talking About Transplantation, Question And Answers for Kidney Transplant
Candidates About Kidney Allocation, http://www.unos.org/docs/Kidney_Brochure.pdf
(Accessed 2014).
[xxv]
Video, The Kidney Allocation System, What Candidates Need to Know, http://vimeo.com/107481347 (Accessed
2014).
[xxvi]
Neurology on Demand, The New Kidney
Allocation System, https://storify.com/nephondemand/the-new-kidney-transplant-allocation-system (Accessed 2014).
[xxvii]
Neurology on Demand, The New Kidney
Allocation System, https://storify.com/nephondemand/the-new-kidney-transplant-allocation-system (Accessed 2014); Video, The Kidney
Allocation System, What Candidates Need to Know, http://vimeo.com/107481347 (Accessed
2014).
[xxix]
Id. Neurology on Demand, The New Kidney Allocation System, https://storify.com/nephondemand/the-new-kidney-transplant-allocation-system (Accessed 2014)
[xxx] http://optn.transplant.hrsa.gov/converge/resources/allocationcalculators.asp?index=81
(Accessed 2014). (This is a KDPI
calculator so you can calculate you KDPI.
According to Indiana University, my KDPI is 44.
[xxxi]
Video, The Kidney Allocation System, What Candidates Need to Know, http://vimeo.com/107481347 (Accessed
2014).
[xxxiii] Video, The Kidney Allocation System, What
Candidates Need to Know, http://vimeo.com/107481347
(Accessed 2014).
[xxxiv]
Id. See letter dated November 3, 2014
from Indiana University Health offering a consent to an 85% KDPI kidney.
[xxxv]
. Neurology on Demand, The New Kidney Allocation System, https://storify.com/nephondemand/the-new-kidney-transplant-allocation-system (Accessed 2014); http://optn.transplant.hrsa.gov/converge/resources/allocationcalculators.asp?index=81
(Accessed 2014).
[xxxvi]
Video, The Kidney Allocation System, What Candidates Need to Know, http://vimeo.com/107481347 (Accessed
2014).
[xxxvii]
Id. (“The actual graft survival for any donor kidney is dependent on
patient-specific factors:
I. Age
Ii. Diagnosis
Iii. HLA
mismatching(http://www.uptodate.com/contents/hla-matching-and-graft-survival-in-kidney-transplantation)
(hemophagocytic lymphohistiocytosis (HLH) is an
aggressive and life-threatening syndrome of excessive immune activation,
http://www.uptodate.com/contents/clinical-features-and-diagnosis-of-hemophagocytic-lymphohistiocytosis)
Iv. Compliance
with treatment protocols
V. Other
factors
Vi. The
transplant team can determine the best options for the patient.”).
[xxxviii]
Video, The Kidney Allocation System, What Candidates Need to Know, http://vimeo.com/107481347 (Accessed
2014).
[xlvi]
Id.
[liv]
Id.
[lv]
Ajay K. Israni, Nicholas Salkowski, Sally Gustafson, Jon J. Snyder, John J. Friedewald, Richard N. Formica‖, Xinyue Wang, Eugene
Shteyn, Wida Cherikh, Darren Stewart, Ciara J. Samana, Adrine Chung, Allyson Hart and
Bertram L.
Kasiske, New National Allocation Policy for Deceased Donor Kidneys in the
United States and Possible Effect on Patient Outcomes, http://jasn.asnjournals.org/content/early/2014/05/14/ASN.2013070784.abstract
(December 19, 2013).
[lvi]
Id.
