i-Base

CD4 percentage (CD4%)

CD4% – percentage of total lymphocytes (white blood cells) that are CD4 cells.

The CD4% is generally more stable than the CD4 count. For example, if you ever get a CD4 count that is much lower than you expect, first see whether the CD4% has changed too,

If the CD4% is still roughly the same then the low CD4 count is unlikely to show a real change.