HIV/AIDS

Updated 25 June 2014

The interaction between viral load, CD4 cell count and disease progression

The "dance" between CD4 cell counts and viral loads can predict how fast or slow the final stages of Aids kick in in an HIV positive patient, but what are they and what role do they play in the progression of HIV/Aids?

0

The "dance" between CD4 cell counts and viral loads can predict how fast or slow the final stages of Aids kick in in an HIV positive patient, but what are they and what role do they play in the progression of HIV/Aids?

What is the “viral load” and how is it measured?
The viral load refers to the actual number of viruses in the blood. The viral load can be “counted” by doing a blood tests (e.g. the quantitative PCR or Polymerase Chain Reaction technique).

The virus count is indicated in copies per ml.

Viral load is an indication of how sick an HIV infected person is (prognosis), and it is also used to measure a person’s response to antiretroviral treatment.

What is the CD4 cell count?
The CD4 lymphocyte count is an excellent indicator of how healthy the immune system is. The CD4 cell count is indicated in cells per mm3, and it is measured by taking a blood sample.

Although the normal number of CD4 cells varies from individual to individual, it is usually between 800 and 1 500.

CD4 cell counts are the best predictors of the risk of opportunistic diseases. CD4 values below 500 cells per mm3 are usually an indication of immune suppression and vulnerability to opportunistic infections. (For example, preventative treatment for tuberculosis should start when a patient’s CD4 cell count drops below 350 cells per mm3.)

The “dance” between viral load, CD4 count and disease progression
There is a very special relationship between the viral load and the CD4 cell count, and if considered together, they can predict whether a person’s journey towards Aids (the final stage of disease) will be rapid or slow.

Viral load and CD4 cells vary together, which means that a higher viral load will lead to a lower CD4 count (because the virus destroys the CD4 cells), while a lower viral load will go hand in hand with a higher CD4 cell count (because less viruses in the blood give the immune system a chance to built up its resources again).

Disease progression (the extent to which an HIV+ person gets sick with opportunistic diseases and infections) will depend on the viral load as well as the CD4 cell count in the blood. The higher the viral load, and the lower the CD4 cell count, the easier it will be for all kinds of infections to attack the body.

The progression to the final phase of Aids (and death) will therefore be much faster with a high viral load.

On the other hand: An HIV-infected person with a low viral load and a high CD4 count can stay healthy for many years, because the immune system is strong enough to fight off infections.

Take home point: An HIV+ person should do everything in his or her power to keep the immune system as healthy for as long as possible (in other words: to keep the viral load as low and the CD4 cell count as high as possible.) This can be done through the following:

  • a healthy lifestyle (rest, exercise)
  • stress management and positive living
  • a healthy, balanced diet
  • supplements and immune-boosters
  • avoidance of the use of recreational drugs, alcohol abuse and smoking
  • routine visits to the doctor or clinic - early treatment of opportunistic infections
  • antiretroviral therapy
 

Read Health24’s Comments Policy

Comment on this story
0 comments
Add your comment
Comment 0 characters remaining

Ask the Expert

HIV/Aids expert

Dr Sindisiwe van Zyl qualified at the University of Pretoria before working for an HIV/AIDS NPO in Soweto for many years. She was named one of the Mail & Guardian's Top 200 Young South Africans in 2012.

Still have a question?

Get free advice from our panel of experts

The information provided does not constitute a diagnosis of your condition. You should consult a medical practitioner or other appropriate health care professional for a physical exmanication, diagnosis and formal advice. Health24 and the expert accept no responsibility or liability for any damage or personal harm you may suffer resulting from making use of this content.

* You must accept our condition

Forum Rules