T-CELL CLONALITY (GAMMA)

Container Type: Lavender top (EDTA); paraffin embedded tissue and/or slides.

Specimen Type: Whole blood, bone marrow; paraffin embedded tissue and/or slides.

Alternate Specimens: ACD or sodium citrate whole blood (lavender, yellow, or blue top tube).

Preferred Volume: 5 mL whole blood, 1 mL bone marrow, 1 paraffin embedded tissue block or 6 unstained 7-micron slides with an additional H&E stained slide containing at least 50% tumor cells.

Minimum Volume: 3 mL whole blood, 0.5 mL bone marrow, 1 paraffin embedded tissue block or 4 unstained 7-micron slides with an additional H&E stained slide containing at least 20% tumor cells.

Submit original unopened tube only. Indicate source.

The T cell receptor (TCR) is composed of two different protein chains (heterodimer). In more than 90% of T cells, this consists of an alpha and beta chain, whereas in the rest of T cells this consists of gamma and delta chains. During normal T-cell development and maturation, the T-cell receptor undergoes a series of rearrangements to produce a unique antigen receptor with specificity to a discrete antigen. In a healthy person, T-cell development results in a spectrum of mature T-cells that can respond to essentially any antigen encountered by the individual. In T-cell lymphoproliferative disorders, the neoplastic T-cell population shares the same TCR rearrangement pattern and serves as a marker for monoclonality that can be detected by PCR and capillary electrophoresis. In typical reactive populations, no single rearrangement predominates, yielding a detectable polyclonal pattern. Therefore, a prominent TCR gene rearrangement profile (TCRG in this assay) is suggestive for lymphoid malignancy in the appropriate clinical and pathologic setting. Detection of the same profile could be used for monitoring a patient with persistent neoplasm.

Surgical pathology report.

Ambient (room temperature) or refrigerated if delay of more than 72 hours.