Test Overview
Test Methodology

Polymerase Chain Reaction (PCR) with capillary electrophoresis

Test Usage

T cell lymphoproliferative disorders are frequently associated with clonal rearrangements of the T cell receptor beta (TRB) locus. Evaluation of the TRB locus may occasionally demonstrate clonal rearrangements not detected by T cell receptor gamma (TRG) testing. This test employs multiplexed PCR primers to detect gene rearrangements involving the variable and joining regions and diversity and joining regions of the TRB locus. In conjunction with clinical, morphologic and immunophenotypic data, the detection of these clonal rearrangements may be useful in the distinction of a lymphoproliferative disorder from a non-neoplastic process. In addition, the comparison of rearrangements detected within lymphocytic infiltrates from separate samples may be useful in determining their clonal relationship. The clinical implications of gene rearrangement results must always be interpreted in the context of the individual patient’s clinicopathologic presentation.

Reference Range *

*Reference ranges may change over time. Please refer to the original patient report when evaluating results.
Interpretive report provided.

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Limitations

A negative result does not exclude a T cell neoplasm. This assay is sensitive to a level of approximately 15% clonal lymphocytes. Factors such as uncommon rearrangements may also result in false negative results. Higher sensitivity may be obtained by ordering both TRG and TRB gene rearrrangement studies. A positive result is not synonymous with neoplasia or specific to neoplasms of T cell origin. Clinicopathologic correlation with gene rearrangement results is required. Insufficient cellular content may result in an inadequate result.

Test Details
Days Set Up
Monday - Friday
Analytic Time

3 - 10 days

Soft Order Code
TRB
MiChart Code
T Cell Clonality- TRB Gene Rearrangement
Synonyms
  • Gene Rearrangement, TCRbeta
  • T Cell Gene Rearrangement
  • Gene Rearrangement, T Cell
  • TCR Beta GR by PCR (TRB by PCR)
  • Gene Rearrangement, T-Cell
  • T Cell Beta Gene Rearrangement
  • TRB Gene Rearrangement
  • TCRbeta Gene Rearrangement
  • T-Cell Clonality
  • T cell antigen receptor, beta, Gene Rearrangement
Laboratory
Molecular Diagnostics
Section
Molecular Diagnostics
Specimen Requirements
Collection Instructions

Collect blood or bone marrow in a lavender top tube. Refrigerate and send intact blood or bone marrow specimen within 48 hours of collection. Fresh tissue (preferably 0.5cm3, sent in RPMI) and fresh aspirates or body fluids are acceptable. Refrigerate and send, preferably within 24 hours. Frozen tissue specimens – preferably frozen with 1 hour of collection – may also be sent frozen on dry ice. Fresh cell suspensions in RPMI should be refrigerated and sent, preferably within 48 hours. Frozen cell suspensions – preferably frozen with 1 hour of collection – may also be sent frozen on dry ice. For formalin-fixed, paraffin-embedded tissue, a tissue block is preferred. Unstained, UNBAKED slides (5-8, 10-micron slides; 10-15 if few neoplastic cells are present) with associated H&E stained slide are also acceptable. Decalcified tissue or other fixatives will be accepted and the assay attempted, however these may result in failed testing due to degraded nucleic acid. Both blocks and slides should be stored at room temperature.

Alternate Specimen
The preferred specimen is whole blood or bone marrow collected in EDTA (lavender top). However, ACD (yellow top) and heparin (green top) may also be accepted. Previously extracted DNA may also be accepted.
Lavender Top Tube
Normal Volume
5 mL EDTA (lavender) whole blood; 3 mL EDTA (lavender) bone marrow; Fresh/frozen tissue and fresh aspirates or body fluids; Fresh/frozen cells in RPMI; Formalin-fixed, paraffin-embedded tissue. Extracted DNA is also acceptable if extracted in a CLIA certified laboratory.
Additional Information

By ordering this test the clinician acknowledges that informed consent has been obtained from the patient as required by applicable state or federal laws and the ordering clinician has authorization from the patient permitting MLabs to report the test results to the ordering clinician. Test includes pathologist interpretation of results billed as a separate additional charge. This test is not available without interpretation.

Billing
CPT Code
81340
Fee Code
NA065
Pro Fee CPT
G0452-26
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