HIV, AIDS, and the CD4 Count

HIV, AIDS, and the CD4 Count

In this article

• How HIV Affects CD4 Cells
• When to Have a CD4 Count Test
• What the CD4 Count Test Results Mean
• Factors That Can Affect Your CD4 Count

What the CD4 Count Test Results Mean continued...

The test does not always correspond with how well you are feeling. For example, some people can have high CD4 counts and do poorly. Others can have low CD4 counts and have few complications.

If your CD4 count goes down over several months, your doctor may recommend:

• Beginning or changing antiretroviral therapy.
• Starting preventive treatment for opportunistic infections.

Public health guidelines recommend starting on preventive antiretroviral therapy for all HIV positive patients whether or not there are symptoms. If therapy is effective, your CD4 count should go up or become stable.

Most doctors recommend starting medication for opportunistic infections at these levels:

• Less than 200: pneumocystis pneumonia (PCP).
• Less than 50: mycobacterium avium complex (MAC).

Factors That Can Affect Your CD4 Count

You should know that other factors can influence how high or low your CD4 count is.

• CD4 counts tend to be lower in the morning and higher in the evening.
• Acute illnesses such as pneumonia, influenza, or herpes simplex virus infection can cause CD4 counts to go down for a while.
• If you have a vaccination or when your body starts to fight an infection, your CD4 counts can go up or down.
• Cancerchemotherapy can cause CD4 counts to go way down.
• Fatigue and stress can also affect test results.

For these reasons:

• Try to use the same lab each time.
• Have your tests done at the same time of day each time.
• Wait for at least a couple of weeks after an infection or vaccination before getting a CD count test.