Porphyria Educational Services
PORPHYRIA EDUCATIONAL SERVICES BULLETIN
Vol. 1 No. 52
December 19, 1999
FOCUS: Porphyrin Red Blood Cell Testing
Another of the tests for porphyria is that of the porphyrin red
blood cell.
Often it is given in conjunction with a 24 porphyrin urine test.
Other names for this tests are: uroporphyrin levels;
protoporphyrin
levels; porphyrins, total; coproporphyrin levels
Porphyrins are pigments found in both animal and plant life.
The Nobel Laureate, Hans Fischer in 1930, called porphyrins
that which
"make the grass green, and the blood red".
Coproporphyrin, protoporphyrin, and uroporphyrin are three
porphyrins
related to red blood cells that can normally be measured in small
amount in the human blood stream.
Protoporphyrin is normally found in highest quantity and thus
this
test is occasionally known as the PROTO test.
Additional tests must be performed to know the levels of specific
porphyrins.
The test is undertaken by drawing blood from a vein (venipuncture).
The point of entry is often from the inside of the elbow or
the back of the
hand.
The puncture site is cleaned with antiseptic, and a tourniquet (an
elastic
band)
or blood pressure cuff is placed around the upper arm to apply
pressure
and restrict blood flow through the vein.
When this is done it causes veins below the tourniquet to
distend
(fill with blood).
A needle is inserted into the vein, and the blood is collected in
an air-tight vial or a syringe.
Midway through the procedure, the tourniquet is removed so
that
the blood circulation cam resume. Once the blood has
been collected,
the needle is removed, and the puncture site is covered to
stop any
bleeding.
The sample is then placed in ice and taken immediately to the
laboratory.
Sometimes when the needle is inserted to draw blood, it is found
that
some people will feel moderate pain. The majority of people will
feel only
a
prick or stinging sensation. Afterward, there may be some
throbbing.
The test is performed do that physicians can diagnose porphyrin
disorders involving red blood cells.
This test specifically measures total porphyrin levels, but
reference
values for the individual components are also included:
The normal value ranges are as follows:
total porphyrin levels: 16 to 60 mcg/dl
coproporphyrin levels: < 2 mcg/dl
protoporphyrin levels: 16 to 60 mcg/dl
uroporphyrin levels: < 2 mcg/dl
Note: mcg/dl = micrograms per deciliter
It must be remembered that when you undertake this test you must
follow
the dietary restrictions. If you do not follow the dietary
restrictions it
will often alter and invalidate test results.
\When you test results show abnormal increased levels of
coproporphyrins, it may indicate congenital erythropoietic
porphyria,
as well as sideroblastic anemia.
Increased protoporphyrin levels may indicate that the patients
has
infection, thalassemia, sideroblastic anemia, lead poisoning,
iron deficiency anemia, erythropoietic anemia , or increased
erythropoiesis.
Increased uroporphyrin levels iften indicate erythropoietic
protoporphyria.
This test must be ordered by your physician.
In order to prepare for the test you must be fasting for 12 to 14
hours
prior
to the time of this test. i You may drink water right
before the test.
If you have any carbohydrate intake, you will compromise your
test.