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HelpTest Code LAB1231735 CD8 T-Cell Immune Competence, Global, Blood
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Reporting Name
CD8 Immune Competence, BSpecimen Type
WB Sodium HeparinShipping Instructions
Testing performed Monday through Friday. Specimens not received by 4 p.m. Central time 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 mailer.
It is recommended that specimens arrive within 24 hours of collection.
Necessary Information
Ordering healthcare professional name and phone number are required.
Specimen Required
Supplies: Ambient Shipping Box-Critical Specimens Only (T668)
Container/Tube: Green top (sodium heparin)
Specimen Volume: 15 mL
Collection Instructions: Send whole blood specimen in original tube. Do not aliquot.
Reject Due To
| Gross hemolysis | Reject |
| Gross lipemia | Reject |
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| WB Sodium Heparin | Ambient | 48 hours | GREEN TOP/HEP |
Specimen Minimum Volume
10 mL
Day(s) Performed
Monday through Friday
Specimen Retention Time
PBMC: 7 days.Report Available
3 to 6 daysReference Values
Interferon-gamma (IFN-gamma) expression (as % CD8 T cells): 10.3-56.0%
CD107a/b expression (as % CD8 T cells): 8.5-49.1%
Reference values have not been established for patients who are <19 years of age.
Useful For
Determining overimmunosuppression within the CD8 T-cell compartment, when used on transplant recipients and patients with autoimmune disorders receiving therapy with immunosuppressant agents
CPT Code Information
86356 x 2
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| GLIC | CD8 Immune Competence, B | 80222-3 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 30643 | IFN-g | 95204-4 |
| 30644 | CD107a/b | 95203-6 |
| 30645 | Interpretation | 69052-9 |
Method Description
Peripheral blood mononuclear cells (PBMC), which contain CD8 T cells, are stimulated with a mixture of phorbol myristate acetate and ionomycin, and with stimulatory signals derived using antibodies against the costimulatory molecules CD28/CD49d. The cells are simultaneously treated with a mixture of brefeldin A and monensin, which blocks extracellular secretion of interferon-gamma (IFN-gamma), enabling intracellular retention and detection of the protein. PBMC that have not been stimulated are used as a control to determine the background levels of IFN-gamma and CD107a and CD107b. The cells are analyzed on the BD FACSCanto flow cytometer and analysis involves gating (defining) of the CD8 T cells using an antihuman CD8 antibody. Specific IFN-gamma and CD107a and CD107b signals are determined within the "gated" CD8 T-cell population. Global CD8 T-cell immune competence is measured by the amount of IFN-gamma produced (CD8 T-cell functional activity) and surface expression of CD107a and CD107b (cytotoxicity assessment) relative to the unstimulated control and is interpreted on the basis of the reference range determined from healthy adult donors.(Unpublished Mayo method)
Supportive Data
The 95% confidence interval reference values were determined from 102 healthy adult donors.