CD4 Count Test

The CD4 Count Test is an indicator of the working of the immune system. By measuring the number of CD4 T lymphocytes or CD4 cells in the blood, it helps to predict and assess the progression of HIV. This count helps in planning antiretroviral therapy or ART. Monitoring the CD4 count through regular blood tests helps to determine the efficacy of the ART and whether the patient is at risk for other infections.

The CD4 lymphocytes are WBC that play a vital role in infection protection. HIV virus tag on to CD4 cells to propagate and spread the infection within the body. Thus an infected person will notice a reduced count of CD4 cells (less than 200 cells/mm3) when the normal range of CD4 cells is from 500 cells/mm3 to 1,200 cells/mm3.

Successful ART results in reduced CD4 count and lesser viral load in the blood. CD8 cells are another type of WBC that work against infections in the body including HIV.