Q and A

Question

What are normal ranges for a CD4 count, the CD4% and the CD4:CD8 ratio?

Answer

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.

62 comments

  1. Roy Trevelion

    Hi Cheri, It’s good that your son in taking ART, and that he talks to you about his test results.

    However, the CD4 and CD8 results tell you how well the immune system is doing. If someone isn’t taking their meds correctly the viral load result is the test that can show it.

    Your son’s CD4 and CD8 results are strong. The normal range for CD4/CD8 ratio is between 0.9 and 1.9. And the average normal CD4% for HIV negative adults is around 40%. Your son’s absolute CD4 count would be a good indication of the strength of his immune system.

    However, if someone isn’t taking their meds correctly HIV will bounce back, and the viral load will become detectable.

    There is much more about CD4 and CD8 ranges on the question above:
    http://i-base.info/qa/20

  2. Cheri

    Hello, my son is HIV positive and he always brings me his test results. I have to google what they mean so I can help him and encourage him. Because, I don’t really know what they mean. He is 24 years old and goes to his doctor’s care providers. Well, I am looking at his most recent blood test results and I am appointments on his own. So, I don’t have the opportunity to talk to his health confused about some of his results. His CD4/ CD8 ratio is 0.7 and highlighted to be low. His CD8 Absolute is 2196 which is considered to be high. His CD4 percent is 36.2% and it says this is low & his CD8 percent is 53.6 and is considered high. He has been on medication consistently for the last 2 years. He tells me that he is taking his meds everyday but from what I have read it seems like he may not be taking his meds consistently looking at these results. My question is from his results do these numbers indicate someone that may be taking their meds correctly? Or do they represent someone that needs to do better at taking meds consistently to better impact their results? Hopefully, you can help answer these questions.

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