A CD4+ count is a blood test to see how well the immune system is working in people who have been diagnosed with 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. If HIV isn't treated, CD4+ counts generally go down as HIV gets worse. In most cases, a low CD4+ count means you have a weakened immune system and a higher chance of getting opportunistic infections.
Why is a CD4+ count done?
CD4+ counts are done to:
Keep track of how the HIV infection is affecting your immune system.
Help diagnose AIDS. If you don't get treatment, HIV infection can progress to AIDS.
Author: Healthwise Staff Clinical Review Board: All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.