PD‑L1 LDT
Use
Programmed cell death ligand 1 (PD‑L1) is a transmembrane protein involved in cellular and humoral immune response regulation. PD‑L1 expression is found on tumor and/or immune cells across a variety of cancers, and this laboratory-developed test (LDT) uses the Zeta PD‑L1 monoclonal antibody clone ZR3 to detect PD‑L1 in formalin‑fixed paraffin‑embedded tissues. The test calculates a Total PD‑L1 Expression score, defined as the sum of staining tumor cells and inflammatory cells divided by total viable tumor cells. Although PD‑L1 expression may inform response to anti‑PD‑1/PD‑L1 therapies, the clinical utility of PD‑L1 (ZR3) has not been determined and there are no standardized scoring criteria; for indications with an FDA‑approved PD‑L1 companion diagnostic, that test is recommended instead.
Special Instructions
Not provided.
Limitations
The utility of PD‑L1 (ZR3) in predicting response to anti‑PD‑1/PD‑L1 therapies has not been established, and no standardized scoring criteria currently exist. For therapies with FDA‑approved PD‑L1 companion diagnostics, use of those approved assays is recommended.
New York Approved
Methodology
Immunoassay (IHC)
Biomarkers
PD‑L1
Protein
Result Turnaround Time
1-2 days
Related Documents
For more information, please review the documents below
Specimen
Tissue (FFPE)
Volume
Not provided
Minimum Volume
Not provided
Collection Instructions
FFPE tissue block preferred or one unbaked, unstained H&E slide (required) plus two to three positively charged unstained slides (4‑5 microns). Blocks and slides must have identifiers matching requisition. Tissue must contain ≥100 viable tumor cells.
Storage Instructions
Use cold pack for transport; do not allow cold pack to contact specimen directly. NYS clients must supply date and time of collection.