T (thymus derived) lymphocyte count

Injury	Disease	Nutrition	Poison

Symptoms	Surgery	Test	Special Topic

Blood test

Overview

Risks

Results

T (thymus derived) lymphocyte count

Alternative Names:

T cell counts; CD4 count; CD3 count; T-lymphocyte count
What the risks are:

Risks associated with having blood drawn are slight:

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

text continues below

Note: This test is often performed on people with altered immune systems. Therefore, the risk for infection may be somewhat greater than when blood is drawn from a person with a normal immune system.

Special considerations:

This test can be affected by:

Stress
Surgery
Chemotherapy medications
Corticosteroids
Immunosuppressive medications
X-rays

A flow cytometric measurement is more accurate than manual counts.

People with decreased T lymphocytes may not react to diagnostic skin tests.

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.