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Granzyme B pin


Granzyme B

Methodology: IHC

Clinical Significance:
Granzyme B is a useful biomarker for cytotoxic T-lymphocytes and natural killer cells, and may aid in differentiating between tumors arising from these cell types and tumors arising from other hematolymphoid cell types. Granzyme B is a serine protease that is the main component in granule-mediated targeted cell lysis. Cytotoxic T-lymphocytes (CTL) and Natural-Killer (NK) cells store granzyme B-containing granules in their cytoplasm and release them during CTL-mediated targeted cell lysis (the ‘cell-mediated’ component of the immune response). After release from the CTL, granzyme B binds its receptor on the target cell, is endocytosed, and remains in the endocytic vesicle until released by perforin. Once released into the target cell cytoplasm, granzyme B can affect cell death via two pathways: 1) initiating a caspase cascade that leads to rapid DNA fragmentation of the target cell (apoptosis) or 2) mediating the release of cytochrome c from the mitochondria, which leads to cell death via necrosis.

Organ: Skin & Mucosa

Disease State: Anaplastic Large Cell Lymphoma (Systemic or Cutaneous)

CPT Code(s): 88342 or 88341. The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.

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