CD4 T-Cell Recent Thymic Emigrants, Blood
Use
Evaluating thymic reconstitution in patients following hematopoietic cell transplantation, chemotherapy, immunomodulatory therapy, and immunosuppression. Evaluating thymic recovery in patients who are HIV-positive and on highly active antiretroviral therapy. Evaluating thymic output in patients with DiGeorge syndrome or other cellular immunodeficiencies. Assessing the naive T-cell compartment in a variety of immunological contexts (autoimmunity, cancer, immunodeficiency, and transplantation). Identification of thymic remnants post-thymectomy for malignant thymoma or as an indicator of relapse of disease (malignant thymoma) or other contexts of thymectomy.
Special Instructions
Testing is performed Monday through Friday. Specimens not received by 4 p.m. (CST) on Friday may be canceled. Samples arriving on the weekend and observed holidays may be canceled. Collect and package specimen as close to shipping time as possible. Ship specimen overnight in an Ambient Shipping Box-Critical Specimens Only (T668) following the instructions in the box. It is recommended that specimens arrive within 24 hours of collection.
Limitations
The CD4 recent thymic emigrants (RTE) assay is likely to be most helpful when used along with measurement of T-cell receptor excision circles (TRECS / T-Cell Receptor Excision Circles Analysis, Blood) for appropriate correlation of thymic output, especially in context of T cell lymphopenia, post-hematopoietic cell transplant and other cellular or combined immunodeficiencies. CD4 RTE measured along with TREC provides a comprehensive assessment of thymopoiesis but should not be used in adults over the sixth decade of life as clinically meaningful information on thymic function is limited in the older population due to a physiological decline in thymic activity.
New York Approved
Methodology
Cell-based / Cytometry (Flow Cytometry)
Biomarkers
LOINC Codes
- 65758-5
- 24467-3
- 8123-2
- 69052-9
Result Turnaround Time
3-4 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
3 mL
Minimum Volume
1.5 mL
Container
Lavender top (EDTA)
Collection Instructions
Send whole blood specimen in original tube. Do not aliquot.
Storage Instructions
Ship specimen overnight in an Ambient Shipping Box-Critical Specimens Only (T668). It is recommended specimens arrive within 24 hours of collection.
Causes for Rejection
Gross hemolysis, Gross lipemia
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 48 hours |