T-Cell Receptor Excision Circles Analysis, Blood
Use
Measuring T-cell output or reconstitution (thymopoiesis) following hematopoietic cell transplantation or highly active antiretroviral therapy. Evaluating thymic function in patients with cellular or combined inborn errors of immunity (formerly primary immunodeficiencies), or receiving immunotherapy or cancer vaccines. Assessing T-cell recovery following thymus transplants for DiGeorge syndrome.
Special Instructions
Specimens must be received in the laboratory on weekdays and by 4 p.m. on Friday. Collect and package specimens as close to shipping time as possible. Ordering physician's name and phone number are required. TREC Assay Patient Information is required but testing will proceed without the form; results are held until info is received.
Limitations
While indicative of thymic function and T-cell recovery, T-cell receptor excision circle (TREC) results cannot be taken as a direct measure of thymic output because TRECs are diluted by peripheral T-cell division and intracellular degradation. The assay should not be ordered on adults over age 60 due to physiological decline in thymic function. Assay results are dependent on the patient's T-cell counts and may be impossible if there are insufficient cells. Temperatures exceeding or below 20 to 25 degrees C and high temperatures causing hemolysis can affect the assay.
New York Approved
Methodology
PCR-based (RT-PCR)
Biomarkers
LOINC Codes
- 62320-7
- 8122-4
- 24467-3
- 14135-8
- 93126-1
- 69047-9
- 48767-8
- 85069-3
- 62364-5
- 18771-6
Result Turnaround Time
6-8 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
Adults: 10 mL; Pediatrics >1 year: 5 mL; Pediatrics ≤1 year: 3 mL
Minimum Volume
Adults: 10 mL; Pediatrics: 1 mL
Container
Lavender top (EDTA)
Collection Instructions
Do not collect specimen using a butterfly needle. Send whole blood specimen in original tube. Do not aliquot.
Patient Preparation
For serial monitoring, collect specimens at the same time of day.
Storage Instructions
Ambient; do not exceed 48 hours.
Causes for Rejection
Gross hemolysis; Gross lipemia
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 48 hours |