Hematological Malignancies T-Cell Receptor (TCR) Gene Rearrangement, PCR

T-cell lymphomas account for approximately 15% of non-Hodgkin lymphomas and may pose a diagnostic challenge on the basis of histopathology alone and particularly in early stages of disease.  The heterodimeric T-cell surface receptors, either alpha/beta (90% -95% of T cells) or gamma/delta (5% - 10% of T cells) are produced following somatic rearrangement of the T-cell receptor (TCR) genes (alpha, beta, delta, and gamma). 

This process is vital to proliferation of T-cells in normal immune function, but can be exploited to aid in the distinction between reactive (benign) versus neoplastic processes of T-cell proliferation.  A reactive, benign T-cell proliferation is characterized by polyclonal expansion of T-cells whereas a malignant process is characterized by clonal expansion of one T-cell population.  In conjunction with morphologic evaluation of lymph nodes, bone marrow and other tissue types the detection of a clonal T-cell gene rearrangement by polymerase chain reaction (PCR) can be used to aid a diagnosis of malignant T-cell lymphoma. 

Clinical Utility:
PCR-based detection of rearranged T-cell receptor genes can be used to help establish a diagnosis of T-cell lymphoma, monitor for treatment response, and/or measure minimal residual disease (MRD).

By extracting genomic DNA from blood, lymph node, bone marrow, or other tissue types T-cell receptor gamma and T-cell receptor beta are amplified by PCR using a multiplex primer method based on the BIOMED-2 strategy.    Precise fragment sizing of the amplicons is accomplished using capillary gel electrophoresis.  The presence or absence of a monoclonal population is determined based on the overall assessment of the gel electrophoretic pattern.

Clinical Sensitivity: 
Approximately 85%
       
Clinical Specificity:
As cross-lineage TCR gene rearrangements have been reported in immature B-cell malignancies, interpretation of this test requires clinical, morphologic, and immunophenotypic correlation.

• 5-10 mL of blood or bone marrow — yellow (ACD) or purple (EDTA) tube; or
• Formalin-fixed paraffin-embedded (FFPE) tissue blocks.
• Fresh Tissue:
  • Stabilize in Allprotect Tissue Reagent (Qiagen) and ship at room temperature – OR
  • Suspend in sterile culture media (RPMI or DMEM) or non-bacteriostatic normal saline in a sterile container and shipped at room temperature – OR
  • Snap Frozen and shipped on dry ice
• If sending DNA: please send 200ng at a minimum of 10ng/µL (DNA must be extracted in a CLIA-certified laboratory or a laboratory meeting equivalent requirements as determined by the CAP and/or CMS)
• Pathology report MUST accompany sample for interpretation of results.

A REQUISITION FORM MUST ACCOMPANY ALL SAMPLES.  Please include detailed clinical information.

Twice per week

5-10 days

• Package and ship specimen to remain cold, but not frozen. 
• Ship via overnight express, using the FedEx priority overnight label provided. 
• Contact Client Services for shipping kits and instructions at (855) 535-1522.

1. Van Dongen JJ, Langerak AW, Bruggemann M, et al. Design and standardization of PCR primers and protocols for detection of clonal immunoglobulin and T-cell receptor gene recombinations in suspect lymphoproliferations: report of the BIOMED-2 Concerted Action BMH4-CT98-3936. Leukemia 2003; 17(12):2257-2317.
2. Langerak AW, Molina TJ, Lavender FL, et al. Polymerase chain reaction-based clonality testing in tissue samples with reactive lymphoproliferations: usefulness and pitfalls. Report of the BIOMED-2 Concerted Action BMH4-CT98-3936. Leukemia 2007; 21:222-229.