Methodology: IHC

Clinical Significance:
CXCL13 is a chemokine that is a relatively specific marker of follicular helper T cells (TFH cells), the presumed cell of origin in angioimmunblastic T cell lymphoma and, to a lesser extent, other peripheral T cell lymphomas.  Importantly, CXCL13 is a less sensitive but more specific marker of TFH cells than CD10, bcl-6, or PD-1.    By immunohistochemistry, CXCL13 shows granular cytoplasmic reactivity in well-fixed FFPE, but may yield false negative results in suboptimally fixed FFPE. Subcellular Localization: Cytoplasmic (typically granular)

Organ: Blood/Bone Marrow

Disease State: Angioimmunoblastic T Cell Lymphoma

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