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HelpTest Code MISC2MAYOTCGRV T-Cell Receptor Gene Rearrangement, PCR, Varies
Reporting Name
T Cell Receptor Gene Rearrange, VUseful For
Determining whether a T-cell population is polyclonal or monoclonal using body fluid or tissue specimens
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
VariesShipping Instructions
Body fluid or spinal fluid specimens must arrive within 4 days of collection.
Specimen Required
Submit only 1 of the following specimens:
Preferred:
Specimen Type: Paraffin-embedded tissue
Container/ Tube: Paraffin block
Collection Instructions:
1. Decalcified specimens (eg, bone marrow core biopsies) are not acceptable.
2. Indicate specimen source.
3. Include pathology report.
Specimen Stability Information: Ambient
Additional Information: If the quality of the biopsy specimen is poor, testing should not be ordered. Testing may be canceled if DNA requirements are inadequate.
Acceptable:
Specimen Type: Tissue slide
Slides: 20 Unstained slides
Container/Tube: Transport in plastic slide holders
Collection Instructions:
1. Send 20 unstained, nonbaked slides with 5-micron thick sections of tissue.
2. Decalcified specimens (eg, bone marrow core biopsies) are not acceptable.
3. Indicate specimen source.
4. Include pathology report.
Specimen Stability Information: Ambient
Additional Information: Testing may be canceled if resultant extracted DNA does not meet concentration requirements.
Specimen Type: Body fluid
Sources: Pleural, peritoneal, vitreous and spinal fluid
Container/Tube: Sterile container
Specimen Volume: At least 5 mL
Collection Instructions:
1. If the volume is large, pellet cells prior to sending.
2. Send less volume at ambient temperature or as a frozen cell pellet.
3. Specify the type of fluid being submitted.
Specimen Stability Information:
Body fluid: Ambient 4 days/Refrigerated/Frozen
Cell pellet: Frozen
Specimen Type: Frozen tissue
Container/Tube: Plastic container
Specimen Volume: 100 mg
Collection Instructions:
1. Freeze tissue within 1 hour of collection.
2. Indicate specimen source.
Specimen Stability Information: Frozen
Specimen Type: Extracted DNA
Container/Tube: 1.5- to 2-mL tube
Specimen Volume: Entire specimen
Collection Instructions:
1. DNA must be extracted within 7 days of collection.
2. Label specimen as extracted DNA and source of specimen.
3. Provide volume and concentration of DNA on label.
Specimen Stability Information: Frozen (preferred)/Refrigerated/Ambient
Additional Information: DNA must be extracted in a CLIA-certified laboratory or equivalent and must be extracted from a specimen type listed as acceptable for this test (including applicable anticoagulants). We cannot guarantee that all extraction methods are compatible with this test. If testing fails, one repeat will be attempted, and if unsuccessful, the test will be reported as failed and a charge will be applied.
Specimen Minimum Volume
Body fluid: 1 mL; Frozen tissue: 50 mg; Extracted DNA: 50 microliters (mcL) at 20 ng/mcL; Tissue slides: 10 unstained slides
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Varies | Varies | |
Special Instructions
Reference Values
An interpretive report will be provided.
Day(s) Performed
Monday through Friday
Test Classification
This test was developed using an analyte specific reagent. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
81340-TCB (T cell antigen receptor, beta) (eg, leukemia and lymphoma), gene rearrangement analysis to detect abnormal clonal population(s), using amplification methodology (eg, PCR)
81342-TCG (T cell receptor, gamma) (eg, leukemia and lymphoma), gene rearrangement analysis, evaluation to detect abnormal clonal population(s)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| TCGRV | T Cell Receptor Gene Rearrange, V | In Process |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 19936 | Final Diagnosis: | 22637-3 |
| MP016 | Specimen: | 31208-2 |
| 608953 | Signing Pathologist | 19139-5 |
Clinical Information
The T-cell receptor (TCR) genes (alpha, beta, delta, and gamma) are comprised of numerous, discontinuous coding segments that somatically rearrange to produce heterodimeric cell surface TCR, either alpha/beta (90%-95% of T cells) or gamma/delta (5%-10% of T cells). With rare exceptions (eg, some neoplastic B-lymphoid proliferations), other cell types retain the germline configuration of the TCR genes without rearrangement.
The marked diversity of somatic TCR-gene rearrangements is important for normal immune functions but also serves as a valuable marker to distinguish abnormal T-cell proliferations from reactive processes. A monoclonal expansion of a T-cell population will result in the predominance of a single TCR-gene rearrangement pattern. In contrast, reactive T-cell expansions are polyclonal (or multiclonal), with no single clonotypic population predominating in the population of T cells. These distributive differences in both TCR sequence and genomic rearrangement fragment sizes can be detected by molecular techniques (ie, polymerase chain reaction) and used to determine if a population of T cells shows monoclonal or polyclonal features.
Interpretation
Results will be characterized as positive, negative, or indeterminate for a clonal T-cell population and include an interpretive report.
In the appropriate clinicopathologic setting, a monoclonal result is associated with a neoplastic proliferation of T cells (see Cautions).
Method Description
Genomic DNA is extracted from the specimen. T-cell receptor beta (TCRB) and T-cell receptor gamma (TCRG) loci (official designations TRB and TRG, respectfully) are amplified by polymerase chain reaction (PCR) using a multiplex primer method based on the BIOMED-2 strategy. Specific primers are labeled with fluorochrome dyes, permitting precise fragment sizing of PCR products by capillary gel electrophoresis using a genetic analyzer. Each amplified locus is assessed for gene rearrangement patterns and an overall interpretation of the assay is made with regards to the presence or absence of a monoclonal population.(Unpublished Mayo method)
Report Available
7 to 14 daysReject Due To
| Bone marrow core biopsies | Reject |
| Paraffin shavings | Reject |
Method Name
Polymerase Chain Reaction (PCR)
Forms
1. Hematopathology Patient Information (T676)
2. If not ordering electronically, complete, print, and send a Hematopathology/Cytogenetics Test Request (T726) with the specimen.