Q and A

Question

What is a normal CD4 count, CD4% and CD4:CD8 ratio?

Answer

After finding out you are HIV positive, your doctor will run several blood tests.

One will be for your immune system and will include your CD4 and CD8 count. Of these, the CD4 count is the most important main result but the CD4% and CD4:CD8 ratio are also sometimes useful.

This Q&A include information about these cels and about interpreting the test results.

CD4 cells are a type of blood cell that is part of your immune system. They are a type of white blood cell (lymphocyte). CD4 cells are sometimes called T-helper cells or T-cells

There are two main types of T-cells.

  1. CD4 cells, also called T4 cells, are “helper” cells. They lead the attack against infections.
  2. CD8 cells, (T8 cells), are “suppressor” cells that complete the immune response. CD8+ cells can also be “killer” cells that kill cancer cells and other cells that are infected by a virus.

CD4 and CD8 counts

The normal ranges for CD4 and CD8 counts vary depending on the lab and test. On average, the normal CD4 range for an HIV negative person is between 460 and 1600. This is an average. Anywhere in this range is good.

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.

The exact CD4 count is not so important. CD4 counts can vary from day to day and even from hour to hour. So the general CD4 result is more important than the exact number.

A normal CD8 range is from 150 to 1000. This test is not used as much but the results come together. It is more important to know your CD4 count than your CD8 count.

CD4 percentage (CD4%)

If you get a CD4 count that is ever unexpectedly high or low, then your CD4% (CD4 percentage) can show whether this is a real change in immune function. The CD4% is a more stable marker than the absolute CD4 count.

The CD4 percentage refers to percentage of total lymphocytes that are CD4 cells. If your test reports CD4% = 34%, that means that 34% of your lymphocytes are 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 – from about 25% to 65%.

CD4:CD8 ratio

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%, the CD4:8 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).

The CD4:CD8 ratio might be better at predicting future risk in people whose CD4 count is high (above 500 cells/mm3). However, not all studies agree on this.

Other studies have shown that starting ART soon after HIV infection has a much higher chance of keeping the CD4:CD8 ratio higher than 1.0.

Note: this answer was last updated in January 2018 from a post that was originally published in December 2006.

332 comments

  1. Josh Peasegood

    Hi, please see here for more information about testing and transmission: https://i-base.info/qa/factsheets/hiv-transmission-and-testing

  2. Pol

    Witam. Nie jestem hiv plus ale zrobilem prywatnie badanie Cd4/ CD8,poniewarz mam ogòlnie obniżone limfocyty ( nie wiadomo dla czego? Inne wyniki OK i na nic nie choruję). Zrobilem tez immunocytometrie ( na ktòrą czekam) .Oto wyniki Cd4/ cd8..CD3+CD4+ TOTAL =333K/MM3 , CD3+CD8+TOTAL=218K/MM3 , CD4/CD8=1.53 To dobre czy złe?

  3. Josh Peasegood

    Hi Kanthony, have you been offered a follow up test with these results and do you know your viral load?

    An absolute CD4 count of 326 means your immune system has been damaged by HIV but you are not at risk for all HIV opportunistic infections. Your immune system is still functioning but not as well as it could be.

    The result of your CD4% does not quite match with your absolute count. A CD4% of 10% usually means an absolute count less than 100 which has not been reported here.

    Have you now started treatment? and how long have you been living with HIV for?

    You can find more information about CD4 result interpretation here: https://i-base.info/ttfa/section-1/9-interpreting-cd4-results-cd4-count-and-cd4-percentage/

  4. Kanthony

    Good evening.

    I have recieved a result of

    Cd3 Abs – 2778
    CD4 Abs- 326
    CD4%- 10.2
    CD8 Abs- 190
    CD8%- 74

    Please assist my understanding of this result.

  5. Josh Peasegood

    Hi Ben, it is great to hear that you had started treatment so soon after testing positive. As you now have an undetectable viral load it shows that your treatment is working.

    Is this the first CD4 count test you have had? or has there been other testing since finding out your status?

    Depending on what your CD4 count was to start with, a lower CD4 count can take a longer time for recovery to a healthy range. This is normal and is expected. As your viral load is now undetectable it suggests your body is able to naturally recover it’s own CD4 cells.

    When below 200 it is recommended to be on an antibiotic called co-trimoxazole. This is a medication used to prevent other infections as your immune system recovers. Have you been told what your CD4%? This is often more reliable than the actual count as this number can fluctuate due to other infections/vaccines, recent exercise and even the time of day.

  6. Ben

    I have been hiv positive for almost three years. I started treatment with Arv two weeks after induction. I have now had an undetectable viral load for two years and several months. in the last tests, my CD4 count was 190. I am very worried. what does this mean?

  7. Josh Peasegood

    Hi Rick, can I ask what HIV treatment you are taking and what side effects you get? Have you had any resistance testing throughout your treatment to check that your medication is still working?

    Taking gaps between medication can risk it not working as well. It is good that your CD4 count is still going up from what it was in 2012, but there is some risk of it not working as well. Do you know what your current viral load is?

    Your absolute count is a little low. A healthy range is considered between 430 and 1690, ideally being more than 500. Your CD4% matches quite well to your absolute count. A CD4% of 12% can be anywhere between 200-350 absolute count. Only a small increase is required for you to be in a healthy range. This will be achieved by continuing with your medication.

    Treatment works by suppressing HIV and making the viral load undetectable. When the viral load is this low it means HIV is no longer damaging your immune cells. Your body can then naturally recover its own immune system.

    Your situation is not dire. With treatment you will be able to recover to within a normal range for your CD4 count. How is your health in general?

  8. Rick

    Hello, I read all of the above and I now understand how to interpret my results. Based on what I just read, it appears my situation is quite dire. Here are my results dated 18 December 2023:

    Absolute CD4 Helper – 396

    (Normal range listed is between 359 to 1519, so I’m just barely within normal range)

    % CD4 Pos. Lymph. – 12%

    (It says I’m “Below Low Normal” range. Normal range is between 30.8% to 58.5%)

    It doesn’t look good for me right now but am I right to conclude that if I start taking my HIV medication daily as I should (I miss as much as a week’s worth of medication every month, sometimes more, sometimes I go without taking my meds for months at a time) that I could recover my CD4 count eventually? I had been diagnosed with AIDS back in 2012 when it was discovered I had only 143 CD4 cells but I took my meds daily and soon completely recovered my immune system. I know I should’ve learned my lesson from that 2012 scare and never miss another dose again but unfortunately, the medication sometimes causes unpleasant symptoms and so I tend to overlook taking them. Now I will get my priorities straight and push myself not to miss any more doses moving forward.

    Please feel free to correct me on anything I got wrong and I would deeply appreciate any feedback from a medical professional. Thank you for your time and consideration Have a wondrous day!

  9. Josh Peasegood

    Hi Narayanan, have you done an HIV test?

    Your CD4 count and CD4% are all within healthy ranges. This suggests HIV has not damaged your immune system.

    Did your doctor explain these results to you?

  10. G Narayanan

    Hi,

    Absolute CD3 Count(T Lymphocyte) – 1795 /µL
    CD-3 (T-Lymphocyte) – 83.5 %
    Absolute CD4 Count – 660 /µL
    CD4 – 30.7 %
    Absolute CD8 Count – 1078 /µL
    CD8 – 50.1 %
    CD4/CD8 Ratio – 0.613 Ratio
    Absolute Lymphocyte Count – 2150 Cells/cmm

    What the results is meaning I’m ok or in danger?
    Can any one clear this

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