Question
What is a normal CD4 count, CD4% and CD4:CD8 ratio?
16 January 2018. Related: All topics, CD4 and viral load, Other tests.
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.
- CD4 cells, also called T4 cells, are “helper” cells. They lead the attack against infections.
- 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.
Hi John, We are not doctors so it’s a good idea to dicuss any TB diagnosis with them. But treating HIV and TB can be complex. IRIS (Immune Reconstitution Inflammatory Syndrome) and usually happens in the first few weeks or months of starting HIV treatment, and with a CD4 count under 50. There’s more about IRIS answered on this question here.
My last question is about the Iris TB, which mostly occurs in 5 to 10 months of Art, I am from India and my country and Africa is 2 of the county where iris tb are every common. My doctor has started my art treatment without giving me any tb medicine. Is it because I had no tb or my CD4 count was fine enough to avoid tb treatment? Or should every individual who has CD4 count less than 100 be given Tb treatment regardless to his Tb detection?
Hi John, It’s great that you’ve started treatment. It looks as though it’s going well. You can read more about life expectancy from Simon’s answer here.
My viral load was around 2 million and CD4 count was 72 when I was diagonised 3 months back. And in 6 week of treatment my CD4 counts was 162 and after 3 months of treatment the CD4 is 220 and viral load of 160.
I have referred to the given site for life expectancy, what I notice is that people starting treatment in CD4 350 or more has good life expectancy.
And what kind of complication one might face in future with CD4 count lower than 500 and undetectable viral loads? Sorry for asking asking too much question. I find your advice very educating.
Hi John.
You’re doing well. Your viral load is nearly undetectable. (For it to be undetectable it needs to be less than 350) And your CD4 count has risen. In time this will rise even more.
Yes you’re out of danger.
With regards to life expectancy please see Q10:
http://i-base.info/qa/what-are-the-most-asked-questions
Could you rephrase the last Q?
Hi, this is John again…I really appreciate your words and I am really glad that you got back. Well after 3 months on virday, my CD4 count was 220 but my cd3 and CD4 % is 9.5( what this means ?) and viral load is 160 copeis/ ml. It was nearly about 2 million when I started the treatment. Is this counted as undetectable? And what is life expectancy for me if I have this CD4 counts and viral load? Am I out of danger or am I still in danger ? And I am very much worried about the iris tb which so far I heard that it occurs in 5 to 10 months of art treatment.
Hi Mark, That’s great, it sounds like a very strong immune system. As it says on this question above, The CD4% is a more stable marker than the absolute CD4 count. And the “normal” percentage in an HIV negative person is from about 25% to 65%.
Hi.
Strange question here. Im the 10+ years that Ive been on HAART, my CD4 has ALWAYS been above, and often far above, the normal range (1400-2450), with an undetectable viral load.
One doctor i see swears there has to be something doctors are missing for it to be that high. The CD4% is typically from 45-62%, and CD4/8 above 2.0.
Is there something they should be looking for?
2 years ago I changed insurance plans and the ID doctor I see now is perplexed by it, and in his 20+ years practicing only had one other patient with a similar bloodwork.
(We are sure it is not lab error because it happens every time and with multiple different laboratories.)
Or should we just be happy they are (beyond) high?
Hi Sasa,
What meds are you taking? Some of the early HIV meds were linked to fat accumulation. But mordern ART has fewer of these side effects. However, you have many different symptoms so it’s a good idea to ask your clinic to check all of these.
It can help sometimes if you change your ARVs. But a resistance test will tell you if your drugs are not working well, rather than if they are causing side effects.
Taking multivitamins can interact with your meds. And that means you could be getting the wrong dose of your HIV meds.
Hi, I have been struggling with gut problems. Diarrhea for the past two years. I have done tests (Colonoscopy, gastroscopy). Have also done resistance tests to the medication I am taking. The resistance test cam back fine. Nothing was picked up on the other tests done. I have lost more than 25 kg. I eat excessively everyday as I have a lot of appetite. I also take a multivitamin daily and vitamin injection to boost. No of these seem to work as I would like to gain the weight as the water I am losing is causing skin problems as well.