This test uses flow cytometry to identify and quantify CD8+ T lymphocytes, also known as suppressor or cytotoxic T cells, in a patient’s blood or other relevant sample. CD8+ T cells play a key role in cell-mediated immunity, helping to eliminate virus-infected cells, tumor cells, and regulate immune responses.

The test involves staining cells with fluorescently labeled anti-CD8 antibodies and analyzing them using a flow cytometer. Results provide the percentage and absolute count of CD8+ T cells, which can aid in assessing immune status, monitoring immunodeficiency, autoimmune disorders, infections, and response to immunotherapy.