CD4 Lymphocyte Count
What is CD4 Lymphocyte Count?
CD4 lymphocyte count, also known as CD4 count, is a lab test that measures the number of CD4 cells in a person’s blood. CD4 cells are type of white blood cell, which is a key type of cell that helps the body fight off infections. CD4 counts are used to monitor and diagnose HIV infection and other immunosuppressive conditions, and to guide treatment decisions.
Preparation for CD4 Lymphocyte Count
Before you have this test, your health care provider may suggest that you:
- Stop taking antiretroviral medication or other immune-modulating drugs such as systemic corticosteroids
- Avoid immunizations for one to two weeks before the test
- Stop taking immunosuppressant drugs two weeks before the test.
Inform your health care provider if you are on any medications or have any conditions that might affect your CD4 count.
Types of CD4 Lymphocyte Test
This test is done in two common ways:
- Flow cytometry – This is the most common way to measure CD4 cells. It involves taking a sample of your blood, which is then analyzed in a laboratory using a machine called a flow cytometer. This method can give a very detailed picture of the types of CD4+ cells present in your blood.
- CD4 enumeration –This is an older and less-accurate method of measuring CD4 cells. It involves counting the number of CD4 cells in a sample of your blood, using a microscope or special computer program.
Risks of CD4 Lymphocyte Count Test
There are no serious risks associated with having a CD4 count. The most common side effect is a mild sting where the needle is inserted.
Why do CD4 Lymphocyte Count Test?
CD4 counts are important because they can help health care providers:
- Determine if a person is infected with HIV
- Monitor HIV infection over time
- Diagnose other immunosuppressive conditions
- Guide treatment decisions
When to Do CD4 Lymphocyte Test?
Your health care provider may order a CD4 count when you are suspected of having HIV or other immunosuppressive diseases, or if you are being treated for HIV or another immunosuppressive condition. CD4 counts can help your health care provider choose the right medications and monitor your treatment response.
