Test Name: CD4
CD4 is expressed strongly on the membrane of a subset of normal T-cells (helper T-cells) and of T-cell precursors starting at the medullary thymocyte stage (where it is co-expressed with CD8), as well as of normal mature and immature monocytic and dendritic cells (at lower density than on the T-cells). CD4 expression may be detected by immunohistochemistry in subsets of T-lymphoblastic lymphoma, peripheral T-cell lymphoma, tissue infiltrates of acute monocytic/monoblastic leukemia (monocytic sarcoma), dendritic cell proliferations (e.g. Langerhans cell histiocytosis) and plasmacytoid dendritic cell 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.