Test Name: CD8
CD8 is variably expressed by on the membrane of subsets of normal T cells (cytotoxic alpha/beta T-cells, gamma/delta T-cells), NK cells and on precursor T-cells starting at the medullary thymocyte stage (where it is co-expressed with CD4) and splenic endothelial cells (littoral cells). It is also expressed at variable levels by subsets of precursor and mature T-cell neoplasms, and by some splenic vascular neoplasms.
A formalin-fixed, paraffin-embedded (FFPE) tissue block is preferred specimen type or one (1) unbaked, unstained slide cut at 4-5 microns for H&E staining (required) and two to three (2-3) positively charged unstained slides cut at 3-4 microns for each test/antibody ordered.
Storage and Transport
Use cold pack during transport of paraffin blocks and unstained slides. Cold pack should not be placed in direct contact with the specimen during shipping
Specimen Rejection Criteria
Turn Around Time (TAT): 2-3 Days
CPT Codes*: 88341, 88342, 88360
*The CPT codes provided with our Test Descriptions are based on AMA guidelines and are for informational purposes only. Correct CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed.