T-cell Receptor Beta (TRB) Clonality Detection by PCR and Capillary Electrophoresis

CPT Code(s)

[4:16 PM] David, Marjorie P 81340, G0452

Synonym(s)

TCR Beta Gene Clonality Detection, T-cell Receptor (TCR) Beta Gene Rearrangement, PCR, TCRB

Performed

Molecular Diagnostics Laboratory

Clinical Indication and Relevance

The assay is useful to assist with the diagnosis of T-cell malignancies. The assay can also be used to detect minimal residual disease in follow-up samples.

Methodology

DNA is isolated and amplified by PCR using BIOMED-2 primers targeting Vß, Dß and Jß sequences. The gene rearrangements are detected by analyzing the PCR products by capillary gel electrophoresis. The assay sensitivity for detection of clonal T-cell populations is 10% of lymphocytes.

Minimum Specimen Requirements

Collect

  • Peripheral blood (PB): 3-5 mL, in purple top (sodium EDTA) tube.
  • Bone marrow (BM): 1-3 mL, drawn into a syringe containing anticoagulant and then
    delivered in purple top tube (EDTA).
  • Fresh or frozen tissue: fresh tissue should be obtained in a sterile manner, and a minimum
    3 mm3
    of tissue is required. Fresh tissue should be placed in culture medium for transport
    or snap frozen (see transport section below).
  • Formalin-fixed, paraffin-embedded (FFPE) tissue blocks: send tissue block to the lab, or
    contact lab for instructions regarding cutting paraffin sections for molecular studies.

 

Transport

  • PB or BM sample: Deliver immediately at 2-8°C (wet ice or cold packs). Do not freeze.
  • Fresh tissue samples should be delivered at room temperature in RPMI culture medium within 3 hours of collection, or snap frozen in liquid nitrogen at -70°C and packed in
    dry ice for delivery. Please do not allow frozen tissues to thaw.
  • Formalin-fixed paraffin embedded (FFPE) tissue blocks and slides can be delivered at controlled temperatures, not to exceed 30C.

 

Stability
PB or BM samples: ambient – 1 hour; refrigerated – 48 hours.

 

Unacceptable Samples

  • Serum or plasma; frozen PB or BM; clotted blood; severely hemolyzed samples
  • Paraffin tissue fixed in Zenker’s, B5, or Bouin’s fixatives
  • Bone marrow biopsy decalcified in formic acid

Turnaround time

Five to seven working days

View Requisition Sheet