|
About
Nephrotic Syndrome
Childhood
Nephrotic Syndrome
Childhood Nephrotic Syndrome can occur at any age but is most common between
the ages of 1-1/2 and 8 years. It seems to affect boys more often than girls.
A child
with Nephrotic Syndrome has these signs:
- High levels of protein
in the urine
- Low levels of protein
in the blood
- Swelling resulting
from buildup of salt and water
Nephrotic
Syndrome is not itself a disease, but it
can be the first sign of a disease that
damages the tiny blood-filtering units (glomeruli)
in the kidneys, where urine is made.
What are the kidneys and what do they do?
The kidneys are two bean-shaped organs found
in the lower back. They are about the size
of a fist. They clean the blood by filtering
out excess water and salt and waste products
from food. Healthy kidneys keep protein
in the blood, which helps the blood soak
up water from tissues. But kidneys with
damaged filters may let protein leak into
the urine. As a result, not enough protein
is left in the blood to soak up the water.
The water then moves from the blood into
body tissues and causes swelling. You may
see swelling around your child's eyes, belly
and legs. Your child may urinate less often
than usual and may gain weight from the
excess water.
How
is Nephrotic Syndrome diagnosed?
To diagnose childhood Nephrotic Syndrome, the doctor may ask for a urine sample
to check for protein. The doctor will dip a strip of chemically treated paper
into the urine sample.
A strip of
chemically treated paper will change color
when dipped in urine with too much protein.
Too much protein in the urine will make
the paper change color. Or the doctor may
ask for a 24-hour collection of urine for
a more precise measurement of the protein
and other substances in the urine.
The doctor
may take a blood sample to see how well
the kidneys are removing wastes. Healthy
kidneys remove creatinine and urea nitrogen
from the blood. If the blood contains high
levels of these waste products, some kidney
damage may have already occurred. But most
children with Nephrotic Syndrome do not
have permanent kidney damage.
In some cases,
the doctor may want to examine a small piece
of the child's kidney under a microscope to see
if substances there are causing the syndrome.
The procedure of collecting a small tissue sample
from the kidney is called a biopsy, and it is
usually performed with a long needle passed through
the skin. The child will be awake during the
procedure and receive calming drugs and a local
painkiller at the site of the needle entry. General
anesthesia is used in the very rare cases where
open surgery is required. The child will stay
overnight in the hospital to rest and allow the
health care team to ensure that no problems occur.
Minimal
Change Disease
The most common form of the Nephrotic Syndrome
in children is called Minimal Change Disease.
Doctors do not know what causes it. The
condition is called Minimal Change Disease
because children with this form of Nephrotic
Syndrome have normal or nearly normal biopsies.
If your child is diagnosed with Minimal
Change Disease, the doctor will probably
prescribe prednisone, which belongs to a
class of drugs called corticosteroids. Prednisone
stops the movement of protein from the blood
into the urine, but it does have side effects
that the doctor will explain. Following
the doctor's directions exactly is essential
to protect your child's health. The doctor
may also prescribe another type of drug
called a diuretic, which reduces the swelling
by helping the child urinate.
When protein
is no longer present in the urine, the doctor
will begin to reduce the dosage of prednisone.
This process takes several weeks. Some children
never get sick again, but most do develop swelling
and protein in the urine again, usually following
a viral illness. However, as long as the child
continues to respond to prednisone and the urine
becomes protein free, he or she has an excellent
long-term outlook without kidney damage.
Children who
relapse frequently, or who seem to be dependent
on prednisone or have side effects from
it, may be given a second type of drug called
a cytotoxic agent. The agents most frequently
used are cyclophosphamide, chlorambucil
and cyclosporine. After reducing protein
in the urine with prednisone, the doctor
may prescribe the cytotoxic agent for a
while. Treatment with cyclophosphamide and
chlorambucil usually lasts for 8 to 12 weeks,
while treatment with cyclosporine frequently
takes longer. The good news is that most
children "outgrow" this disease
by their late teens with no permanent damage
to their kidneys.
Other
Conditions That Involve Childhood Nephrotic
Syndrome
In about 20 percent of children with Nephrotic
Syndrome, the kidney biopsy reveals scarring
or deposits in the glomeruli. The two most
common diseases that damage these tiny filtering
units are focal segmental glomerulosclerosis
(FSGS) and membranoproliferative glomerulonephritis
(MPGN). Very rarely, a child may be born
with a condition that causes Nephrotic Syndrome
(congenital nephropathy).
Since
prednisone is less effective in treating
these diseases than it is in treating Minimal
Change Disease, the doctor may use additional
therapies, including cytotoxic agents. Recent
experience with a class of drugs called
ACE inhibitors (a type of blood pressure
drug) indicates that these drugs help prevent
protein from leaking into the urine and
keep the kidneys from being damaged in children
with Nephrotic Syndrome.
Nephrotic
Syndrome in Adults
Nephrotic Syndrome is a condition marked
by very high levels of protein in the urine
(proteinuria); low levels of protein in
the blood; swelling, especially around the
eyes, feet, and hands; and high cholesterol.
Nephrotic Syndrome results from damage to
the kidneys' glomeruli (the singular form
is glomerulus). Glomeruli are tiny blood
vessels that filter waste and excess water
from the blood and send them to the bladder
as urine.
Nephrotic
Syndrome can occur with many diseases, including
the kidney diseases caused by diabetes mellitus,
but some causes are unknown. Prevention
of Nephrotic Syndrome relies on controlling
these diseases.
Treatment
of Nephrotic Syndrome focuses on identifying
the underlying cause, if possible, and reducing
high cholesterol, blood pressure and protein
in urine through diet, medications, or both.
One group of blood pressure medications
called ACE inhibitors also protects the
kidneys by reducing proteinuria.
Nephrotic
syndrome may go away once the underlying
cause, if known, has been treated. In children,
80 percent of cases of Nephrotic Syndrome
are caused by Minimal Change Disease, which
can be successfully treated with prednisone.
However, in adults, most of the time the
underlying cause is a kidney disease such
as membranous nephropathy or focal segmental
glomerulonephritis, and these diseases often
persist even with treatment. In these cases,
the kidneys may gradually lose their ability
to filter wastes and excess water from the
blood. If kidney failure occurs, the patient
will need dialysis or a kidney transplant.
Source:
National Kidney and Urologic Diseases Information
Clearinghouse
3 Information Way
Bethesda, MD 20892-3580
Email: nkudic@info.niddk.nih.gov
The National Kidney and Urologic Diseases Information Clearinghouse (NKUDIC)
is a service of the National Institute of Diabetes and Digestive and Kidney
Diseases (NIDDK). The NIDDK is part of the National Institutes of Health under
the U.S. Department of Health and Human Services. Established in 1987, the
clearinghouse provides information about diseases of the kidneys and urologic
system to people with kidney and urologic disorders and to their families,
health care professionals, and the public. NKUDIC answers inquiries, develops
and distributes publications, and works closely with professional and patient
organizations and Government agencies to coordinate resources about kidney
and urologic diseases.
Publications produced by the clearinghouse are carefully reviewed by both NIDDK
scientists and outside experts.
This e-text is not copyrighted. The clearinghouse encourages users of this
e-pub to duplicate and distribute as many copies as desired.
NIH Publication No. 00-4695
May 2000
And
NIH Publication No. 03-4624
August 2003
|
