CD4 Count and HIV Viral Load

Definition

CD4 cells are white blood cells that initiate the immune response against viruses and bacteria. CD4 count measures the number of these cells in the blood. The viral load test shows the amount of HIV in the blood.

Purpose

Serves three purposes in a person living with HIV:

1. Monitoring immune status, risk of opportunistic infection and certain cancers 2. Assessing treatment effectiveness, together with the viral load test 3. Determining disease stage, aiding AIDS diagnosis

Results

CD4 (cells/mm³)Meaning
500 to 1,200Normal range for a healthy adult and adolescent
< 500Low
≤ 200AIDS diagnosis, high risk of serious infection
Above normalMay suggest infection or a blood cancer

With consistent adherence to treatment, CD4 count usually rises; this helps preserve health and prevent progression to AIDS.

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