| English | Thesaurus |
| CD8 Cell | A type of lymphocyte. CD8 T lymphocytes (CD8 cells) recognize and destroy cells infected with microorganisms, such as bacteria or viruses. |
| CD4 Cell | A type of lymphocyte. CD4 T lymphocytes (CD4 cells) help coordinate the immune response by stimulating other immune cells, such as macrophages, B lymphocytes (B cells), and CD8 T lymphocytes (CD8 cells), to fight infection. HIV weakens the immune system by destroying CD4 cells. |
| CD4 cell percentage | Percentage of white blood cells that are CD4 T lymphocytes (CD4 cells). In certain cases, such as during acute HIV infection or HIV infection in children younger than 5 years of age, CD4 percentage is used rather than CD4 count to assess HIV progression or response to antiretroviral therapy (ART). |
