Alternative names
B lymphocyte cell surface markers

Definition
This is a test that looks for characteristic “marker” proteins on the surface of B-lymphocytes (a type of white blood cell). These markers may be helpful in the diagnosis of leukemia or lymphoma.

How the test is performed

A sample of white blood cells is obtained by drawing blood from a vein, or less commonly, bone marrow biopsy. The test may also be done on a lymph node biopsy when lymphoma is suspected.

Blood is usually drawn from a vein on the inside of the elbow or the back of the hand. The puncture site is cleaned with antiseptic, and an elastic band is placed around the upper arm to apply pressure and restrict blood flow through the vein. This causes veins below the band to fill with blood. A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. During the procedure, the band is removed to restore circulation. Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

For an infant or young child, the area is cleansed with antiseptic and punctured with a sharp needle or a lancet. The blood may be collected in a pipette (small glass tube), on a slide, onto a test strip, or into a small container. Cotton or a bandage may be applied to the puncture site if there is any continued bleeding.

In the laboratory, the sample of white blood cells will undergo immunophenotyping (determination of the specific cell type and characteristics).

How to prepare for the test
No special preparation is usually necessary.

For Infants and children:
The preparation you can provide for this test depends on your child’s age, previous experiences, and level of trust. For specific information regarding how you can prepare your child, see the following topics:

 
• infant test or procedure preparation (birth to 1 year)  
• toddler test or procedure preparation (1 to 3 years)  
• preschooler test or procedure preparation (3 to 6 years)  
• schoolage test or procedure preparation (6 to 12 years)  
• adolescent test or procedure preparation (12 to 18 years)

How the test will feel
When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.

Why the test is performed
This test may be performed when other tests (such as a blood smear) indicate abnormal white blood cells, when leukemia or lymphoma is suspected, or to differentiate the type of leukemia or lymphoma.

What abnormal results mean

Abnormal results on this test may indicate lymphocytic leukemia or lymphoma. (Leukemia is the uncontrolled growth of white blood cells. Lymphoma is a tumor of the lymph nodes or lymph tissue.)

What the risks are

 
• excessive bleeding  
• fainting or feeling light-headed  
• hematoma (blood accumulating under the skin)  
• infection (a slight risk any time the skin is broken)  
• multiple punctures to locate veins

Special considerations
This test is highly specialized and may not be available at all general laboratories.

Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

Medical Encyclopedia

All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.