HIV/AIDS Glossary

CD4 Count

Synonym(s): CD4 Cell Count, CD4 T Lymphocyte Count

A laboratory test that measures the number of CD4 T lymphocytes (CD4 cells) in a sample of blood. In people with HIV, the CD4 count is the most important laboratory indicator of immune function and the strongest predictor of HIV progression. The CD4 count is also used to monitor a person’s response to antiretroviral therapy (ART).

Related Term(s): CD4 Percentage, CD4 T Lymphocyte, HIV Progression

Search the Glossary

What's this?


AIDSinfo Glossary App

Download Glossary