Anemia in Kidney Disease and Dialysis

Anemia in Kidney Disease
and Dialysis�
What is anemia?
Anemia is common in people with kidney
A
disease. Healthy kidneys produce a hor-
person whose blood is low in
mone called erythropoietin, or EPO,
red blood cells has anemia. Red
which stimulates the bone marrow to pro-
blood cells carry oxygen (O ) to
2
duce the proper number of red blood cells
tissues and organs throughout the body
needed to carry oxygen to vital organs.
and enable them to use the energy from
Diseased kidneys, however, often don’t
food. Without oxygen, these tissues
make enough EPO. As a result, the bone
and organs—particularly the heart and
marrow makes fewer red blood cells.
brain—may not do their jobs as well as
Other common causes of anemia include
they should. For this reason, a person
blood loss from hemodialysis and low
who has anemia may tire easily and look
levels of iron and folic acid. These nutri-
pale. Anemia may also contribute to
ents from food help young red blood cells
heart problems.
make hemoglobin, their main oxygen-
carrying protein.
Healthy kidneys
produce a hormone
Healthy kidney �
Normal
called erythropoietin,
oxygen
Normal EPO
or EPO, which stimu-
lates the bone marrow
to make red blood
cells needed to carry
oxygen throughout
the body. Diseased
Normal
kidneys don’t make
red blood cells
enough EPO, and
bone marrow then
makes fewer red
blood cells.
Reduced
Diseased kidney
oxygen
Reduced EPO
Reduced
red blood cells
U.S. Department of Health�
and Human Services�
National Kidney and Urologic Diseases
NATIONAL INSTITUTES OF HEALTH
Information Clearinghouse

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What are the laboratory tests for
How is anemia treated?
anemia?
EPO
A complete blood count (CBC), a laboratory test
If no other cause for anemia is found, it can be
performed on a sample of blood, includes a deter-
treated with a genetically engineered form of EPO.
mination of a person’s hematocrit, the percentage
The EPO is usually injected under the skin two or
of the blood that consists of red blood cells. The
three times a week. Patients on hemodialysis who
CBC also measures the amount of hemoglobin
can’t tolerate EPO shots may receive the hormone
in the blood. The range of normal hematocrit
intravenously during treatment. The intravenous
and hemoglobin in women who have a period is
method, however, requires a larger, more expen-
slightly lower than for healthy men and healthy
sive dose and may not be as effective.
women who have stopped having periods (post-
menopausal). The hemoglobin is usually about
The U.S. Food and Drug Administration (FDA)
one-third the value of the hematocrit.
recommends that patients treated with EPO ther-
apy should achieve a target hemoglobin between
When does anemia begin?
10 and 12 grams per deciliter (g/dL). Recent
studies have shown that raising the hemoglobin
Anemia may begin to develop in the early
above 12 g/dL in people who have kidney disease
stages of kidney disease, when a person still has
increases the risk of heart attack, heart failure,
20 to 50 percent of normal kidney function. This
and stroke. People who take EPO shots should
partial loss of kidney function is often called
have regular tests to monitor their hemoglobin.
chronic kidney disease (CKD). Anemia tends to
If it climbs above 12 g/dL, their doctor should
worsen as kidney disease progresses. End-stage
prescribe a lower dose of EPO. The FDA rec-
kidney disease, the point at which dialysis or
ommends that patients whose hemoglobin does
kidney transplantation becomes necessary, doesn’t
not rise to the target level with normal doses of
occur until a person has only about 10 percent of
EPO ask their doctor to check for other causes of
kidney function remaining. Nearly everyone with
anemia.
end-stage kidney disease has anemia.
Iron
How is anemia diagnosed?
Many people with kidney disease need both EPO
If a person has lost at least half of normal kidney
and iron supplements to raise their hematocrit to
function and has a low hematocrit, the most likely
a satisfactory level. If a person’s iron levels are
cause of anemia is decreased EPO production.
too low, EPO won’t help and that person will con-
The estimate of kidney function, also called the
tinue to experience the effects of anemia. Some
glomerular filtration rate, is based on a blood test
people are able to take an iron pill, but many
that measures creatinine. Experts recommend that
studies show that iron pills don’t work as well in
doctors begin a detailed evaluation of anemia in
people with kidney failure as iron given intrave-
men and postmenopausal women on dialysis when
nously. Iron can be injected into an arm vein or
the hematocrit falls below 37 percent. For women
into the tube that returns blood to the body during
of childbearing age, evaluation should begin when
hemodialysis.
the hematocrit falls below 33 percent. The evalu-
A nurse or doctor will give each patient a test
ation will include tests for iron deficiency and
dose because a small number of people—less than
blood loss in the stool to be certain there are no
1 percent—have a bad reaction to iron injections.
other reasons for the anemia.
If a patient begins to wheeze or have trouble
breathing, the health care provider can give
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epinephrine or corticosteroids to counter the reac-
Points to Remember
tion. Even though the risk is small, patients are
asked to sign a form stating they understand the
n A person whose blood is low in red blood cells
has anemia.
possible reaction and they agree to have the treat-
ment. Patients should talk with their health care
n Anemia is common in people with kidney
providers if they have any questions.
disease.
In addition to measuring hematocrit and hemoglo-
n Healthy kidneys produce a hormone called
bin, the CBC test will include two other measure-
erythropoietin, or EPO, which stimulates the
ments to show whether a person has enough iron.
bone marrow to produce the proper number
of red blood cells needed to carry oxygen to
n The ferritin level indicates the amount of iron
vital organs. Diseased kidneys, however, often
stored in the body. The ferritin score should
don’t make enough EPO.
be no less than 100 micrograms per liter
(mcg/L) and no more than 800 mcg/L.
n A complete blood count (CBC), a laboratory
test performed on a sample of blood, includes
n TSAT stands for transferrin saturation, a score
a determination of a person’s hematocrit, the
that indicates how much iron is available to
percentage of the blood that consists of red
make red blood cells. The TSAT score should
blood cells.
be between 20 and 50 percent.
n If no cause for anemia other than reduced EPO
What are some other causes of
production is found, it can be treated with a
anemia?
genetically engineered form of EPO, which is
usually injected under the skin two or three
In addition to EPO and iron, a few people may
times a week.
need vitamin B12 and folic acid supplements.
n The U.S. Food and Drug Administration (FDA)
If EPO, iron, vitamin B12, and folic acid supple-
recommends that patients treated with EPO
ments do not help, the doctor should look for
therapy should achieve a target hemoglobin
other causes of anemia such as sickle cell disease
between 10 and 12 grams per deciliter (g/dL).
or an inflammatory problem. At one time, alumi-
num poisoning contributed to anemia in people
n People who take EPO shots should have regular
with kidney failure. Many phosphate binders used
tests to monitor their hemoglobin. If it climbs
to treat bone disease caused by kidney failure were
above 12 g/dL, their doctor should prescribe a
antacids that contained aluminum. But aluminum-
lower dose of EPO.
free alternatives are now widely available. People
n Many people with kidney disease need both
with CKD and kidney failure should be sure their
EPO and iron supplements to raise their hema-
phosphate binder and other drugs are free of
tocrit to a satisfactory level.
aluminum.
Anemia keeps many people with kidney disease
from feeling their best. But EPO treatments help
most patients raise their hemoglobin and have
more energy.
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Hope through Research
The USRDS publishes an Annual Data Report,
which characterizes the total population of
The National Institute of Diabetes and Digestive
people being treated for kidney failure; reports
and Kidney Diseases (NIDDK), through its
on incidence, prevalence, mortality rates, and
Division of Kidney, Urologic, and Hematologic
trends over time; and develops data on the
Diseases, supports several programs and studies
effects of various treatment modalities. The
devoted to improving treatment for patients
report also helps identify barriers to the deliv-
with progressive kidney disease and end-stage
ery of quality health care and opportunities for
kidney failure, which is sometimes called end-
more focused studies of renal research issues.
stage renal disease or ESRD, including patients
on hemodialysis:
n The Hemodialysis Vascular Access
Clinical Trials Consortium. This program
n The End-Stage Renal Disease Program. This
is conducting a series of multicenter,
program promotes research to reduce medical
randomized, placebo-controlled clinical trials
problems from bone, blood, nervous system,
of drug therapies to reduce the failure and
metabolic, gastrointestinal, cardiovascular, and
complication rate of arteriovenous grafts and
endocrine abnormalities in end-stage kidney
fistulas in hemodialysis. Recently developed
failure and to improve the effectiveness of dial-
anti-thrombotic agents and drugs to inhibit
ysis and transplantation. The research focuses
cytokines are being evaluated in these large
on reuse of hemodialysis membranes and on
clinical trials.
using alternative dialyzer sterilization meth-
ods; on devising more efficient, biocompatible
Participants in clinical trials can play a more active
membranes; on refining high-flux hemodi-
role in their own health care, gain access to new
alysis; and on developing criteria for dialysis
research treatments before they are widely avail-
adequacy. The program also seeks to increase
able, and help others by contributing to medical
kidney graft and patient survival and to maxi-
research. For information about current studies,
mize quality of life.
visit www.ClinicalTrials.gov.
n The Frequent Hemodialysis Network. This
multicenter clinical trial will test whether
receiving hemodialysis more than the standard
three times a week provides better outcomes.
n The U.S. Renal Data System (USRDS). This
national data system collects, analyzes, and
distributes information about the use of dialy-
sis and transplantation to treat kidney failure
in the United States. The USRDS is funded
directly by the NIDDK in conjunction with the
Centers for Medicare & Medicaid Services.
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For More Information
About the Kidney Failure Series
American Association of Kidney Patients
The NIDDK Kidney Failure Series includes
3505 East Frontage Road, Suite 315
booklets and fact sheets that can help the reader
Tampa, FL 33607
learn more about treatment methods for kidney
Phone: 1–800–749–2257 or 813–636–8100
failure, complications of dialysis, financial help
Fax: 813–636–8122
for the treatment of kidney failure, and eating
Email: info@aakp.org
right on hemodialysis. Free single printed
Internet: www.aakp.org
copies of this series can be obtained by contact-
ing the National Kidney and Urologic Diseases
American Kidney Fund
Information Clearinghouse.
6110 Executive Boulevard, Suite 1010
Rockville, MD 20852
Phone: 1–800–638–8299 or 1–866–300–2900
Fax: 301–881–0898
You may also find additional information about this topic by
visiting MedlinePlus at www.medlineplus.gov.
Email: helpline@kidneyfund.org
This publication may contain information about medications.
Internet: www.kidneyfund.org
When prepared, this publication included the most current
information available. For updates or for questions about any
National Kidney Foundation
medications, contact the U.S. Food and Drug Administration
toll-free at 1–888–INFO–FDA (1–888–463–6332) or visit
30 East 33rd Street
www.fda.gov. Consult your doctor for more information.
New York, NY 10016
Phone: 1–800–622–9010 or
212–889–2210
Fax: 212–689–9261
Internet: www.kidney.org
U.S. Food and Drug Administration
10903 New Hampshire Avenue
Silver Spring, MD 20993
Phone: 1–888–INFO–FDA (1–888–463–6332)
Internet: www.fda.gov
Acknowledgments
Publications produced by the Clearinghouse are
carefully reviewed by both NIDDK scientists and
outside experts. This publication was originally
reviewed by John C. Stivelman, M.D., Emory
University School of Medicine.
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The National Kidney and Urologic Diseases
Information Clearinghouse (NKUDIC) is
a service of the National Institute of Dia-
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(NIDDK). The NIDDK is part of the
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Established in 1987, the Clearinghouse
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This publication is available at
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U.S. DEPARTMENT OF HEALTH
AND HUMAN SERVICES
National Institutes of Health
NIH Publication No. 09–4619
October 2008
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