Download T-Cell Receptor (TCR) Gene Rearrangement, PCR

Laboratory Shipping Address: 2525 SW 3rd. Avenue
Suite 350 Portland, OR 97201
Correspondence Address: 3181 SW Sam Jackson Park Road
Mailstop MP-350 Portland, OR 97239
Phone: 855-KDL-1LAB (535-1522) - Fax: 855-KDL-1FAX (535-1329)
KNIGHT DIAGNOSTIC LABORATORIES
T-Cell Receptor (TCR) Gene Rearrangement, PCR
Test Code: 5592
Department: Molecular Oncology
Test Synonyms:
T-Cell Rearrangement
Gene Rearrangement for T-cell lymphoma
T-Cell Clonality
T-Cell Receptor Gamma Clonality
T-Cell Receptor Beta Clonality
CPT Code(s):
83891
83892
83898 x 2
83909 x 2
Background:
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 or gamma/delta are produced following somatic
rearrangement of the T-cell receptor (TCR) genes (alpha, beta, delta, and gamma). This process is vital to
the function 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 a polyclonal expansion of T-cells, whereas a malignant process is characterized by a clonal
expansion of one specific T-cell population with a unique T cell receptor gene rearrangement. In
conjunction with morphology, flow cytometry, and immunohistochemistry, the detection of a clonal T-cell
gene rearrangements by polymerase chain reaction (PCR) can be used to aid in the diagnosis of malignant Tcell 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).
Methodology:
By extracting genomic DNA from blood, lymph node, bone marrow, or other tissue types T-cell receptor
gamma and/or 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 T cell population is determined based on the
overall assessment of the electrophoretic pattern.
Sensitivity:
> 95% for the detection of clonality in most tissue types.
False negative results could be due to:
•
Rare clone-specific gene rearrangements that do not bind to any of the primers in BIOMED-2 multiplex
mixture.
•
Clonal T cells present at low abundance in polyclonal background, below the analytical sensitivity of the
assay (~1-10%, depending on the loci).
The presence of a clonal T cell receptor gene rearrangement does not always equate to the presence of T
cell malignancy.
Molecular Diagnostics CLIA #38D0881787 |Translational Research Lab CLIA #38D2018256
Q11-TSD-100.01
KNIGHT DIAGNOSTIC LABORATORIES
Laboratory Shipping Address: 2525 SW 3rd. Avenue
Suite 350 Portland, OR 97201
Correspondence Address: 3181 SW Sam Jackson Park Road
Mailstop MP-350 Portland, OR 97239
Phone: 855-KDL-1LAB (535-1522) - Fax: 855-KDL-1FAX (535-1329)
T-Cell Receptor (TCR) Gene Rearrangement, PCR
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. False positive
gene rearrangement results are rare but could result from the inadvertent sampling of a predominant T cell
clone from within a polyclonal population.
Specimen Requirements:
• 5-10 mL of blood or bone marrow — yellow (ACD) or purple (EDTA) tube; or
• formalin-fixed paraffin-embedded (FFPE) tissue block or 10 slides (5 micron)
• Refrigerate or keep at room temperature.
A REQUISITION FORM MUST ACCOMPANY ALL SAMPLES. Please include detailed clinical information.
Test Performed (Days):
Monday, Wednesday, Friday
Turn Around Time:
5-7 days
Shipment Sensitivity Requirements:
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) 5351522.
References:
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.
Molecular Diagnostics CLIA #38D0881787 |Translational Research Lab CLIA #38D2018256
Q11-TSD-100.01