Rheumatoid Arthritis and the CBC Test
Why is a complete blood count (CBC) test useful in the diagnosis of rheumatoid arthritis?
Rheumatoid arthritis is an auto-immune disease which presents as inflammation of
the synovium (lining) of the joints. The detection of this inflammation and determination
of its cause is crucial to distinguishing rheumatoid arthritis from other rheumatic
diseases.
A complete blood count (CBC) test is also usually ordered both for diagnosis of
rheumatoid arthritis as well as for monitoring the progression of the disease and
treatment. This is a test of the red blood cells, the white blood cells, and the
platelets.
An elevated white blood cell count indicates inflammation or infection. The red
blood cell count varies with gender. The hemoglobin / hematocrit is a component
of the red blood cells and is measured in this test also. This is in indicator of
anemia which is often a problem for sufferers of rheumatoid arthritis. Since the
platelets are important in the clotting function of the blood and are often affected
by medications used in the treatment of rheumatoid arthritis, monitoring platelet
count is needed.
The complete blood count test also measures the differential in the types of white
blood cells. There are four types of white blood cells: neutrophils, lymphocytes,
monocytes, and basophils. The count of neutrophils increases with bacterial infections
and acute inflammation. The count of lymphocytes increases in viral infections.
The count of monocytes increases in chronic infections and eosinphils increase in
allergies. Basophils usually do not change.
The CBC test serves as a good indicator of the type of inflammation present and
aids in the diagnosis and monitoring of rheumatoid arthritis. It serves as an indicator
of anemia which is related to the fatigue that rheumatoid arthritis sufferers often
experience. It measures inflammation levels which aid in determining the severity
of the disease or of a current flare-up.
The complete blood count test is used in conjunction with other blood tests to give
a more accurate picture of the current state of rheumatoid arthritis as well as
in the initial diagnosis process.
