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Evaluation of iron status can include several tests that are not always run

together. These include:

a.. Serum iron level - measures the level of iron in the liquid part of your

blood.

b.. Ferritin level - measures the amount of stored iron in your body. Ferritin

is the main protein that stores iron for areas that need it, especially the

liver and the bone marrow (the inside cavity in bones, where blood cells are

made).

c.. Total Iron Binding Capacity (TIBC) - measures the amount of transferrin, a

blood protein that transports iron from the gut to the cells that use it. Your

body makes transferrin in relationship to your need for iron; when iron stores

are low, transferrin levels increase, while transferrin is low when there is too

much iron. Usually about one third of the transferrin is being used to transport

iron. Because of this, your blood serum has considerable extra iron-binding

capacity, which is the Unsaturated Iron Biding Capacity (UIBC). The TIBC equals

UIBC plus the serum iron measurement. Some laboratories measure UIBC, some

measure TIBC, and some measure transferrin.

These tests are often ordered together, and the relative changes in each can

help your doctor determine the cause of an abnormal result in one or more of

these tests.

Several other tests can also be used to help recognize problems with iron in the

body.

a.. Hemoglobin and Hematocrit - While not really tests of iron status alone,

they are widely used parts of the Complete Blood Count (CBC) that can detect

anemia; iron deficiency is a common cause of anemia. Another part of the CBC is

the Mean (average) Cell Volume (MCV), which measures how big the red blood cells

are. In iron deficiency (and in some other diseases as well), not enough

hemoglobin is made, causing the red blood cells to be smaller than normal

(microcytic) and paler than normal (hypochromic).

b.. HFE gene test - The most common genetic disease in people whose ancestors

came from northern Europe is hemochromatosis, a disease that causes your body to

absorb too much iron. It is due to an inherited abnormality in a specific gene,

called the HFE gene, that regulates the amount of iron absorbed from the gut. In

people who have two copies of an abnormal form of the gene, the protein made by

the gene cannot tell the cells in the gut when the body is " full " of iron, so

the gut keeps on absorbing iron and excess iron damages many different organs.

The HFE gene test uses a sample of blood drawn from you arm to see if you have

the mutations that cause the disease (the most common is called C282Y).

c.. Zinc Protoporphyrin - Protoporphyrin is the part of hemoglobin that needs

iron to help it carry oxygen. If there is not enough iron, another metal (such

as zinc) will attach to the protoporphyrin instead. This test, which is simple

to do using only a small amount of blood, is sometimes used as a screening test

for iron deficiency, especially in children. Because lead prevents iron (but not

zinc) from attaching to protoporphyrin, zinc protoporphyrin will also be high in

severe cases of lead poisoning.