Health Encyclopedia

B and T cell screen

Definition

A B and T cell screen is a laboratory test to determine the amount of T and B cells (lymphocytes) in the blood.

Alternative Names

Direct immunofluorescence; E-rosetting; T and B lymphocyte assays; B and T lymphocyte assays

How the test is performed

Blood is drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.

Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm.

Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

Blood could also be obtained by capillary sample (fingerstick, or heelstick in infants).

After the blood is drawn it goes through a two step process. First, the lymphocytes are separated from other blood parts. Once the cells are separated, identifiers are added to distinguish between T and B cells. The E-rosetting test identifies T cells and direct immunofluorescence is used to identify B cells.

How to prepare for the test

Tell your health care provider if you have had any of the following, which might affect your T and B cell count:

Chemotherapy
Surgery
Steroid therapy
Stress
X-rays

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

Your doctor may order this test if you have signs of an immunodeficiency diseases. It may also be used to distinguish between cancerous and noncancerous disease. The test may also be used to determine how well treatment for certain conditions is working.

Normal Values

Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

What abnormal results mean

Abnormal T and B cell counts suggest possible diseases. Further testing is needed to confirm a diagnosis.

An increased T cell count may be due to:

An increased B cell count may be due to:

A decreased T cell count may be due to:

Congenital T-cell deficiency disease
- Nezelof syndrome
- DiGeorge syndrome
- Wiskott-Aldrich syndrome
B cell proliferative disorders
- Acquired immunodeficiency syndrome
- Chronic lymphocytic leukemia
- Waldenstrom's macroglobulinemia

A decreased B cell count may be due to:

Acute lymphoblastic leukemia
Congenital immunoglobulin deficiency disorders
Acquired immunoglobulin deficiency disorders

What the risks are

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.

Other risks associated with having blood drawn are slight but may include:

Excessive bleeding
Fainting or feeling light-headed
Hematoma (blood accumulating under the skin)
Infection (a slight risk any time the skin is broken)

Review Date:8/28/2007
Reviewed By:Daniel R Alexander, MD, Department of Internal Medicine, St. Mary's Hospital, Leonardtown, MD. Review provided by VeriMed Healthcare Network.

ADAM Quality A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is the first of its kind, requiring compliance with 53 standards of quality and accountability, verified by independent audit. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial process. A.D.A.M. is also a founding member of Hi-Ethics (www.hiethics.com) and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

The Agency for Health Care Administration (Agency) and this website do not claim the information on, or referred to by, this site is error free. This site may include links to websites of other government agencies or private groups. Our Agency and this website do not control such sites and are not responsible for their content. Reference to or links to any other group, product, service, or information does not mean our Agency or this website approves of that group, product, service, or information.

Additionally, while health information provided through this website may be a valuable resource for the public, it is not designed to offer medical advice. Talk with your doctor about medical care questions you may have.