24 HOUR PORPHYRIN URINE TEST
Urine Tests is a test that measures the level of
porphyrins in urine.
name for this test is The Uropoprhyrin Test.
The test is
performed by the collection of a urine for a 24-hour
The test must
be ordered by a physician. The ordering physician
will instruct you, if necessary, to discontinue
drugs that may interfere with the test.
Be sure that
the proper preservative has been added to the
collection jug before leaving your doctor's office. Many
a porphyrin urine
test has been compromised because of the wrong
perservative being used or lack of a preservative.
On day 1,
urinate into the toilet upon arising in the morning.
subsequent urine (in a special container) for the next
On day 2,
urinate into the container in the morning upon arising.
Always cap the
into a special "hat" which fits into the
average toilet seat.
Do not let the
voided urine sit in the hat. Pour it immediately
into the collection jug. Exposure to air will compromise
Try to void
with no direct light as exposure of urine to light
diminish the number of porphyrin, and the higher number
in the urine, is what is needed for an accurate
Be sure that
no toilet tissue touches the collection as chemicals
in paper products will compromise the collection.
Keep it in the
refrigerator or a cool place during the collection
period. Ideally the temperature should run between
36-40 degrees, that of
the standard refrigerator setting.
Always be sure
that the container is marked with your name, the
date, the time of completion, and return it as instructed.
Do not let it sit
out in room temperatures or in bright light.
Be sure the receptionist at the lab
takes it to the proper storage
in the lab immediately. Ascertain that it has been
at the lab. Find out when it will be transported
and how it will be
transported to the assaying laboratory. ALso find out
when the assay is to
be run and when the results will be know. Asking
these questions helps
alleviate any problems of a lost specimen and/or
compromised tests results. There are no risks in
performing this test.
The reason that this test is performed
is because of a high degree of
suspicion that the patient may have porphyria.
important function of porphyrins is as components of heme.
Heme is made from iron + protoporphyrin.
made up of four globin proteins + 4 heme groups.
Oxygen binds to the iron in the heme molecules.
of porphyrins exist with the same basic structure.
However the various kinds of porphyrins have
slightly different chemical
biochemical pathway includes conversions from
porphyrins to delta-ALA, then to PBG, then uroporphyrin,
then coproporphyrin, then protoporphyrin, and finally
into the end product, heme.
requires the presence of an enzyme. If any of the enzymes
are deficient (because of a genetic disease or inhibition
by a toxic
substance), a type of porphyria results. Normal values
urine tests are as follows: random urine: negative test
24-hour urine: 50 to 300 mg per 24-hours Note: mg =
undertake this porphyrin urine test you must determine
whether you have taken any drugs which can affect test
include aminosalicylic acid, barbiturates, chloral
hydrate, chlorpropamide, ethyl alcohol, griseofulvin,
contraceptives, phenazopyridine, procaine, and
results which result in increased levels of urinary
PBG may indicate porphyria (several types), hepatic
cancer), hepatitis or lead poisoning .
All too often
porphyrin tests must be repeated a number of times.
Timing is important for many of the tests. The best time
to test is
at the onset of an acute attack and BEFORE
GLUCOSE infusion has begun.
Dr. Robert Johnson, MD
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