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HelpTest Code LAB8644 T-Cell Receptor Gene Rearrangement, PCR, Bone Marrow
Additional Codes
TCGBM
Useful For
Determining whether a T-cell population is polyclonal or monoclonal
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
Bone MarrowShipping Instructions
Specimen must arrive within 7 days of collection.
Necessary Information
Include relevant clinical information and cytogenetics results, if available.
Specimen Required
Container/Tube:
Preferred: Lavender top (EDTA)
Acceptable: Yellow top (ACD)
Specimen Volume: 2 mL
Collection Instructions:
1. Invert several times to mix bone marrow.
2. Send bone marrow specimen in original tube. Do not aliquot.
Specimen Minimum Volume
1 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Bone Marrow | Ambient (preferred) | 7 days | |
| Refrigerated | 7 days |
On-campus collections: Tube to 99 or deliver to University Extension Hospital Room EH318
Send specimen in original tube, Ambient. Specimen must arrive within 7 days (168 hours) of collection.
Off-campus collections: DO NOT SPIN! DO NOT SHARE! Specimen to be stored/transported Ambient.
Special Instructions
Reference Values
An interpretive report will be provided.
Positive, negative, or indeterminate for a clonal T-cell population
Day(s) Performed
Monday through Friday
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 |
|---|---|---|
| TCGBM | T Cell Receptor Gene Rearrange, BM | In Process |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 19957 | Final Diagnosis: | 22637-3 |
| 608952 | Signing Pathologist | 19139-5 |
Testing Algorithm
For information see:
-Bone Marrow Staging for Known or Suspected Malignant Lymphoma Algorithm
Interpretation
An interpretive report will be provided.
Results will be characterized as positive, negative, or indeterminate for a clonal T-cell population.
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 bone marrow. 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
5 to 10 daysSpecimen Retention Time
Bone marrow: 2 weeks; Extracted DNA: 3 monthsReject Due To
| Gross hemolysis | Reject |
| Moderately to severely clotted | 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.