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.

20 comments

  1. Hi Niel

    I’m sorry to hear about your diagnosis. How are you coping with this?

    Your doctor will know more about you and your history, and may have given you this information in order to try and help reassure you. However, the following information might also be useful.

    No-one can predict how quickly or slowly HIV is likely to progress without treatment, and this is the information that I think you should have been told. UK studies show that more than half the people diagnosed in early infection to start treatment within two years. Early infection is defined as within 6-12 months of catching HIV. The same study showed that 25% might not need treatment for ten years.

    So there is a wide range and you can only get an idea of your own personal situation by seeing the trend in your CD4 count and viral load over the first few months.

    I also think your doctor is being unhelpful for another reason that is perhaps more important. This is for suggesting that not using treatment is in itself a good thing. When you start treatment is a decision for you to make in discussion with your doctor.

    For example, if you think you were recently infected and are in early infection, you might want to start treatment because this might have advantages in the long run. Guidelines differ on this – with a stronger recommendation for this in the US compared to the UK – but this should be for you to discuss if appropriate.

    Also, there is an increasing trend for people to start treatment earlier in order to be less infectious to their sexual partners. Many guidelines, including in the US and the UK, say this option should be offered at any CD4 count. Many people report that this can also be a way to normalise some of the stress associated with finding out you are positive.

    In this case, although there is no evidence that there are clinical benefits from starting at higher CD4 counts (ie above 500), again, this should be your choice.

    Modern treatment for many people is simple and effective with few side effects. Rather than continuing to see treatment as something to put off for as long as possible, there is an increasing interest in wanting to reduce the period when viral load is detectable.

    If you are likely to have caught HIV more than 6-12 months ago, it would have been more helpful for your doctor to have said:
    1) that you have a strong CDC4 count which is clearly good
    2) that you will only get an idea of how quickly or slowly HIV progresses without treatment by monitoring over time
    3) it might be 2 years or 10 years until you need treatment – or you might want to at least have the option of earlier treatment if his is right for you
    4) that there is no urgency for treatment, but when you need it, treatment is effective, safe and tolerable
    5) there might be other reasons to start earlier, and that this is a choice for you to think about.

    If this was likely to have been a recent infection, then a discussion of the potential benefits of earlier treatment might also have been useful.

    More details on these issues are in this simple guide to combination therapy.
    http://i-base.info/introduction-to-combination-therapy-2014

  2. i have been recently diagnosed with HIV….my cd4 is 724 and my cd8 is 1263….my doc says i will be ok for at least 4 years without ART….I still feel unsure.
    Pls advise

  3. Hi Tamirat,
    These results mean that your immune system is doing very well. The most important of these is your CD4 count. This is the standard measure used to monitor somebody’s immune system when they have HIV. A ‘normal’ CD4 count (without HIV) is anything between 500-1600. While your CD4 count is above 350 it is very unlikely you will have any symptoms or HIV related illnesses. You can read more about CD4 counts here.

    There is nothing you can do- expect take ARVs- to improve your CD4 count. If you are not on treatment your CD4 count is likely to decrease over time until you decide to start treatment.

  4. my cd4 count is 812 & my cd8 count is 2023 cd4% is 25 woud you tell me my health status & how to improve my cd4/cd8 ?

  5. Hi Mukasa,

    A ratio is usually written as 1:9 or 1:2 and so on. A CD4% of 40 is good and is likely to mean your immune system is strong. The best way of measuring this though is usually the absolute CD4 count. Do you know what your CD4 count is?

  6. What is the problem if my cd4 and cd8 ratio is 40%?

  7. Hi Jack,

    Everybody progresses at different rates so you can’t tell from one CD4 count how long it will take for your CD4 count or ratio to drop. The best way to assess this is to study the CD4 count over time and see how it changes. This is a very high CD4 count though which means that your immune system is still strong. Please follow this link for more information about how CD4 counts progress in different people.

  8. in hiv how quick turns cd4/cd8 ratio less than 1? i have cd4 904/μlt and cd8 561/μlt ratio 1.61. thank you

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