A single iron test does not give a doctor the full picture of the amount of iron that a person has stored and available. It is usually necessary to evaluate the results of several related iron tests together. Ferritin is usually the preferred test to evaluate stored iron, but it is an acute phase reactant, meaning that it may be increased with inflammation or chronic diseases. In these cases, ferritin may not be a good measure of stored iron. The soluble transferrin receptor test is not a routinely order test, but since it is not an acute phase reactant, it may be ordered as an alternative to ferritin to evaluate stored iron when a chronic illness is present or suspected.
4. Why does my doctor want to send a second sTfR test to the same laboratory as the first test?
Test methods and reference (normal) ranges for sTfR will vary slightly from laboratory to laboratory. Your doctor may prefer to send your samples to the same laboratory to make results more directly comparable.
This article was last reviewed on December 15, 2011. | This article was last modified on July 21, 2013.
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