pattern of infection in HIV and different CD4 counts
Last edited 05/2018
pattern of infection in HIV and different CD4 counts
The CD4 count is an indicator of the degree of immunosuppression in those infected with HIV.
- in healthy individuals the CD4 count is usually above 500 cells/µl (some may have naturally lower counts)
- in untreated HIV patients, the average rate of CD4 count decreases between 40-80 cells/µl per year (some may progress faster than others)
- a more rapid decline is likely to be present in patients who are not taking antiretroviral treatment and who have a high viral load
- patients with a CD4 count below 200 cells/µl are at most risk of HIV related problems (1)
Even at low CD4+ve lymphocyte levels, the T lymphocytes that remain still afford some protection against infection. This is manifest in a hierarchy of opportunistic pathogens, which begin to occur as the CD4+ve cell count declines.
CD4 counts and HIV related problems:
CD4 count cells/µl |
risk of opportunistic infection |
risk of HIV-associated |
direct HIV |
500 and below |
little risk |
|
|
400 and below |
|
|
|
350 and below |
|
|
|
200 and below |
|
|
|
100 and below |
|
|
|
Reference:
common opportunistic infections and tumours if HIV and low CD4 count