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"Normal" CD4/CD8 Ratios.


Senior Member
Midwest USA
@Sea, @SOC,

With all the talk of XMEN, I got curious what else was out there about "normal" ratios.

Mostly, things talk about ratios lower than 1 in HIV infection being a bad sign.

But I found some different things that I also found interesting...

If you have a viral infection, your ratio may be decreased...but if you have an autoimmune condition, your ratio may be increased. Considering how often these go together in our population, one has to wonder how useful this measurement is AT ALL.

If your ratio is above 2...does that REALLY mean your immune system is strong...or does it mean it is overreacting to everything...or you have a really terrible infection?

No wonder other sites say this ratio has fallen out of favor. It seems to bring up more questions than it answers.

FWIW, my ratio was 2.2 in 2010, prior to any treatment other than some vitamins etc and is 1.87 as of 11/13.


The CD4/CD8 ratio is a reflection of immune system health. A normal ratio is between 1 and 4. People without HIV infection generally have a greater number of CD4 cells than they have of CD8 cells.

As people get older, the immune system's defence against pathogens is weaker and the CD4/CD8 ratio tends to decrease.

People with autoimmune diseases tend to have an increased CD4/CD8 ratio, while those with viral infections have a decreased ratio.

Factors affecting CD4 count and subsequently the CD4/CD8 ratio are some viral infections, tuberculosis, corticosteroid use, seasonal/diurnal variations, and variations in CD4 analyses.

Although not too much attention is paid to ratios now, one study found that the only independent predictors for immune reconstitution inflammatory syndrome (IRIS) were a low baseline CD4 count and a low CD4/CD8 ratio. Those people with a CD4/CD8 ratio of less than 0.15 were more likely to have an IRIS event than were people with a ratio greater than 0.30.1


A normal CD4/CD8 ratio is 2.0, with CD4 lymphocytes equal to or greater than 400/mm3 and CD8 lymphocytes equal to 200 to 800/mm3.

If your ratio is higher than 2, it means your immune system is strong and you may not have HIV.

If your ratio is less than 1, you may have:

  • HIV

  • Bone marrow problems related to chemotherapy

  • Anemia

  • Multiple sclerosis, myasthenia gravis, or another nervous system condition
Higher than normal results may mean you have:

  • Major infection

  • Viral infection

  • Type of blood cancer