Lab test

CD4 Count Test - Lymphocyte Count for HIV & Immunodeficiency

The Lymphocyte Subset Test Panel measures several types of white blood cells, including CD4 cells, to help monitor immune system health.

Typical price

From $188

Results

1-3 business days

Preparation

See preparation notes below

Sample

Blood draw or sample collection at a local center

The Lymphocyte Subset Test Panel measures several types of white blood cells, including CD4 cells, to help monitor immune system health. It is frequently used to track immune function in people living with HIV and in others with conditions that affect lymphocytes. The panel reports CD3, CD4, CD8, the CD4/CD8 ratio, CD16/56 natural killer cells, and CD19 B cells. A CD4 count helps a healthcare provider understand how well the immune system is functioning over time. It is a monitoring tool, not a diagnosis on its own, and results are interpreted by a clinician.

• CD3 lymphocytes Total T cells, a broad measure of immune cells that coordinate the immune response.
• CD4 lymphocytes Helper T cells that guide the immune response; a key marker for monitoring immune function.
• CD8 lymphocytes Cytotoxic T cells that help destroy infected cells.
• CD4/CD8 ratio The balance between helper and cytotoxic T cells.
• CD16/56 lymphocytes Natural killer cells involved in early defense against infection.
• CD19 lymphocytes B cells that produce antibodies.

• People living with HIV whose healthcare provider is monitoring immune function
• Individuals with an immunodeficiency or an unexplained low lymphocyte count
• People being evaluated for recurrent or unusual infections
• Those whose healthcare provider wants to track immune cells over time
• People with a condition known to affect lymphocytes

• No fasting is required for this panel
• A standard blood draw is used to collect the sample
• Try to schedule testing when you are not acutely ill, unless advised otherwise
• Tell the lab about any medications that affect the immune system

Results list counts for each lymphocyte subset and the CD4/CD8 ratio. A lower CD4 count may indicate reduced immune function, while higher or lower values in other subsets can have various causes. Trends over time are often more useful than a single measurement. A healthcare provider interprets these lymphocyte subset results alongside your overall health, medications, and other tests. Discuss your results with a healthcare provider before making any decisions.

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