Anemia Blood Tests

I got a copy of my blood test results in the mail today, so I have a little more detail on what tests Rheumy ran.  Once again, I had to do some research to understand what each of these tests were for and how to interpret the results.  I have found labtestsonline.org to be a great source of information.  They do a great job of explaining why a certain lab test is done, the background behind how the body functions, and what the results mean.  I gave a brief overview below, but you can click on the links to get a lot more detailed information.


Haptoglobin

Haptoglobin testing is used primarily to help detect and evaluate hemolytic anemia and to distinguish it from anemia due to other causes; however, it cannot be used to diagnose the cause of the hemolysis.

Hemolytic Anemia occurs when the red blood cells (RBC) are destroyed by the body prematurely.  The average RBC lives in the blood for about 4 months.  With Hemolytic Anemia, this can be shortened to just a few days.  The bone marrow is not able to produce new RBCs quickly enough to replace those that have been destroyed, leading to a decreased number of RBCs in the blood, which in turn leads to a diminished capacity to supply oxygen to tissues throughout the body.  This type of condition can be inherited (e.g. Sickle Cell Anemia) or acquired (possibly as a result of an autoimmune disease, such as lupus).

When haptoglobin levels are decreased, along with an increased reticulocyte count and a decreased RBC count, hemoglobin, and hematocrit, then it is likely that you have some degree of hemolytic anemia.

My haptoglobin levels were in the normal range, so I likely do not have hemolytic anemia.



Iron/TIBC/Ferritin

This set of tests is often ordered to differentiate between different types of anemia (a condition that occurs when the level of Red Blood Cells (RBC) and/or Hemoglobin in the blood are decreased).

The Serum Iron test measures the amount of iron in the blood.  The Total Iron Binding Capacity (TIBC) test is used to assess your body's ability to transport iron in the blood.  These two tests allow the transferrin Saturation to be calculated.  Transferrin Saturation reflects the amount of iron being transported in the blood and its capacity to carry more.  The Ferritin test is used to determine your body's total iron storage capacity.

A summary of the changes in iron tests seen in various diseases of iron status is shown in the table below.

Disease	Iron	TIBC/Transferrin	UIBC	%Transferrin Saturation	Ferritin
Iron Deficiency	Low	High	High	Low	Low
Hemochromatosis	High	Low	Low	High	High
Chronic Illness	Low	Low	Low/Normal	Low	Normal/High
Hemolytic Anemia	High	Normal/Low	Low/Normal	High	High
Sideroblastic Anemia	Normal/High	Normal/Low	Low/Normal	High	High
Iron Poisoning	High	Normal	Low	High	Normal

Based on my results, rheumy thinks it may be Anemia due to Chronic Illness.

- a little lupie -