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A CD4+ count is a blood test to see how well the immune system is working in people who have been diagnosed with human immunodeficiency virus (HIV). CD4+ cells are a type of white blood cell. White blood cells are important in fighting infections. CD4+ cells are also called T-lymphocytes, T-cells, or T-helper cells.
HIV infects CD4+ cells. The number of CD4+ cells helps determine whether other infections (opportunistic infections) may occur. In people infected with HIV who are not getting treated, CD4+ counts generally decrease as HIV progresses. A low CD4+ count usually means a weakened immune system and a higher chance of getting opportunistic infections.
CD4+ counts are done to:
How often your CD4+ count is checked depends on your treatment, your health, and your prior CD4+ count results.
Before you have this test, you may have the opportunity to meet with a counselor so that you understand what the test results could mean about your HIV infection.
A health professional uses a needle to take a blood sample, usually from the arm.
When a blood sample is taken, you may feel nothing at all from the needle. Or you might feel a quick sting or pinch.
There is very little chance of having a problem from this test. When a blood sample is taken, a small bruise may form at the site.
In people with HIV, the CD4+ count almost always goes up with treatment. Low CD4+ counts make infections more likely.
Current as of:
February 9, 2022
Author: Healthwise StaffMedical Review: E. Gregory Thompson MD - Internal MedicineAdam Husney MD - Family MedicinePeter Shalit MD, PhD - Internal Medicine
Current as of: February 9, 2022
Author: Healthwise Staff
Medical Review:E. Gregory Thompson MD - Internal Medicine & Adam Husney MD - Family Medicine & Peter Shalit MD, PhD - Internal Medicine
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