Laboratory Tests to Diagnose CLL
CBC: In many cases, the results of a routine blood screen or complete blood cell count (CBC) is enough to diagnose chronic lymphocytic leukemia (CLL).
Typically, the blood results will show an elevated number of mature-looking lymphocytes in the bloodstream. There may be little or no abnormality with the number of red blood cells or platelets in the sample.
Serum Protein Electrophoresis: Serum Protein Electrophoresis (SPEP) is a test that can be used to check the different level of proteins in your blood. In the case of CLL, it may show that your body is not producing adequate amounts of immunoglobulin, or “antibodies.”
Flow Cytometry: Flow cytometry is another blood test that can be useful in the diagnosing of CLL. In this process, cells from your blood are stained with an antibody or a dye that is sensitive to light. The sample is then passed through a laser light source.
The flow cytometry meter can use the way the cells react with the light source to determine a great deal about the number and characteristics of the cells including size, shape, and origin of the abnormal lymphocytes.
Flow cytometry may also be performed on cells collected during a bone marrow aspiration and biopsy.
For the blood testing, a technician in a laboratory will simply draw blood from a vein in your arm using a needle. The needle poke itself will cause a momentary “pinching” sensation, but is usually not painful.
Once the technician has taken a sample of your blood, they will send it off to be analyzed in a lab.
Bone Marrow Biopsy and Aspirate: Your doctor may choose to do a bone marrow biopsy and aspirate, either during the diagnosing stage or just before treatment for your leukemia begins. While this test is not always necessary, it can help your specialist determine how well your leukemia responds to therapy.
Like the CBC, the results of the marrow biopsy will show an increased number of lymphocytes, but it may also show a “crowding out” of healthy marrow cells as well.
During the diagnosing stage, your specialist may also want to do some genetic testing on your leukemia cells. Identifying any chromosomal abnormalities or mutations that are present will help your doctor plan your therapy, and learn more about how your cancer is expected to respond to treatment.
Staging of cancers help doctors to learn how advanced a disease is, and are useful to predict how it will progress and respond to treatment. There are two different staging systems currently in use to stage CLL, the Rai and Binet systems. These systems are similar to each other in that they both stage CLL by sites that are involved in the disease and the effect that the leukemia has had on healthy blood cell production at the time of diagnosis.
The Rai staging system classifies patients into three groups: Low-risk (stage 0), intermediate risk (stages I and II), and high risk (stages III and IV). Patients in the low risk category, or stage 0, show only an increased number of lymphocytes in the blood. Stage I intermediate-risk patients have enlarged lymph nodes and stage II patients will also have
The Binet system has a greater focus on the number of sites of enlarged lymph nodes in staging CLL. Low risk, or stage A patients will have an increased number of lymphocytes in the circulation as well as less than three areas of enlarged lymph node tissues that can be felt by your doctor, whereas intermediate-risk or stage B CLL will have evidence of disease in more than three lymph node areas. In the Binet system, advanced or stage C patients will experience anemia and thrombocytopenia.
Summing it Up
Most of the testing required to diagnose CLL can be done using simple blood samples. Staging of the disease and checking for genetic mutations are additional steps that help specialists to plan treatment for CLL, and predict its course and response to treatment.
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