What are normal ranges for a CD4 count, the CD4% and the CD4:CD8 ratio?
CD4 cells are a type of lymphocyte (white blood cell). They are an important part of the immune system. CD4 cells are sometimes called T-cells.
There are two main types of T-cells. T4 cells, also called CD4+, are “helper” cells. They lead the attack against infections. T8 cells, (CD8+), are “suppressor” cells that end the immune response. CD8+ cells can also be “killer” cells that kill cancer cells and cells infected with a virus.
The normal ranges for CD4 and CD8 counts varies depending on the lab and test, but for an HIV negative person a normal CD4 count is in the range 460 to 1600. This is an average. Anywhere in this range is fine.
Although generally a higher CD4 is good, an HIV negative person with a normal CD4 count of 1200 is not more healthy than someone whose normal count is 400.
A normal CD8 range is from 150 to 1000. This test is not really used so much for monitoring. Knowing your CD4 count is more important.
But CD4 counts can vary from day to day and even from hour to hour. The test itself has is not alway sensitive to the exact number – just the general result.
If you ever get an unexpectedly high or low CD4 count your CD4% (CD4 percentage) will indicate if this is a real change. The percentage refers to total lymphocytes.
If your test reports CD4% = 34%, that means that 34% of your lymphocytes were CD4 cells.
This percentage is more stable than the number of CD4 cells. The average normal CD4% for HIV negative adults is about 40%. However, as with CD4 counts and other test, the range for a “normal” result in an HIV negative person is also wide – i,e. from about 25% to 65%.
The CD4:CD8 ratio is also sometimes used, but less often. This is a measure of how balanced your immune function is. This calculated by dividing the CD4 result by the CD8 result.
In HIV negative people, the normal range for the CD4:CD8 ratio is between 0.9 and 1.9. This means that there are about 1 to 2 CD4 cells for every CD8 cell.
When not on HIV treatment, just like the CD4 count and CD4%, this ratio drops over time. Eventually, unless you start treatment, there will be more CD8 cells than CD4 cells (i.e. the ratio drops to less than 1.0).
Note: this answer was updated in September 2014 from a post that was originally published in December 2006.
Information on this website is provided by treatment advocates and offered as a guide only. Decisions about your treatment should always be taken in consultation with your doctor.