CD4/CD8 ratio

CD4/CD8 ratio EDTA blood (code LYDD)

T cells or T lymphocytes are immune cells, part of the specific cellular defenses. They are specific because each T cell can respond to a specific foreign surface epitope presented by antigen-presenting cells, APCs. The antigen is then presented on the cell membrane of an APC as an antigen/MHC complex.
T cells can be divided into four main groups:

• T helper cell (CD4+ cell)
• Cytotoxic T-cell (CD8+ Cell)
• T-inhibitor cell (CD8+ Cell)
• T-memory cell

The stem cells for all blood cells are located in the bone marrow. However, the maturation of T lymphocytes takes place in the thymus (thymus), from which they derive their name. This process is largely completed before puberty. During their stay in the thymus, the still immature T-cells are trained, so to speak, in making a difference between the body's own and the body's foreign bodies. The majority of T cells in training fail the exam and are destroyed. A minority are allowed to leave the thymus and take up functions as immune cells in the body.

This test looks at the ratio of two important types of white blood cells in your blood.

Lymphocytes are a type of white blood cell in your immune system. This test looks at two of them, CD4 and CD8. CD4 cells lead the fight against infections. CD8 cells can kill cancer cells and other invaders.

If you have HIV, your CD4 cell count may be low. Without HIV treatment, your CD4 cell count is likely to drop. A lack of CD4 cells usually leads to more frequent infections.

This test looks at the ratio of CD4 cells to CD8 cells. The ratio tells your healthcare provider how strong your immune system is and helps predict how likely you are to develop a crippling infection.

In addition to HIV/AIDS, conditions that can be tracked with this test include infectious mononucleosis and other viral infections, chronic lymphatic leukemia, Hodgkin's disease, aplastic anemia, and neurological disorders such as multiple sclerosis and myasthenia gravis.

Why do I need this test?
You may need this test if your healthcare provider thinks you have HIV. Some people infected with HIV may develop flu-like symptoms within a few weeks of acquiring the virus. But other people have no symptoms at all.

Although the test looks at the ratio of CD4 cells to CD8 cells, your healthcare provider may focus on the CD4 count results.

You can also have this test to see how well HIV treatment is working.

What other tests can I have along with this test?
Your healthcare provider may also order other tests to help diagnose HIV.

What do my test results mean?
Test results may vary depending on your age, gender, health history, the method used for the test, and other things. Your test results may not mean you have a problem. Ask your health care provider what your test results mean for you.

Results for the ratio are given as a number. Results for each cell count are given as a number per cubic millimeter (/ mm3).

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
• AIDS if your CD4 count is less than 200/mm3
• Bone marrow problems related to chemotherapy
• Anaemia
• Multiple sclerosis, myasthenia gravis or other nervous system disorders
• Chronic infection

Higher than normal results may indicate:

• Large infection
• Viral infection
• type of blood cancer

What can affect my test results?
Pregnancy can affect your results. Women with HIV may have a higher white blood cell count, which affects the proportion of CD4 cells.

Drinking too much alcohol can also affect your results. Certain medications such as corticosterids may affect your results.