Methodology: IHC

Clinical Significance:
Identifies cell surface-associated protein expressed at relatively high levels by cytotoxic/suppressor T cells (which express the alpha-beta heterodimer of CD8), and at lower levels by gamma-delta T cells and natural killer cells (both of which express the alpha-alpha homodimer of CD8). CD8 is aberrantly decreased in a subset of T cell and NK cell neoplasms.

Subcellular Localization: Membranous

Organ:

Disease State:

CPT Code(s): 88342 or 88341 (reference only; CPTs may vary)

Turnaround Time: Within 1-2 business days of receipt

Schedule: Monday - Friday

Specimen Requirements:
• Formalin-fixed, paraffin-embedded (FFPE) tissue block or cell block - OR -
• 1 unstained slide for each test requested plus 3-4 additional unstained slides cut at 4µm