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HelpTest Code LAB78611 Natural Killer (NK) Function, Blood
Additional Codes
| CCH Test ID |
|---|
| 2900800 |
Performing Laboratory
St. Louis Children's Hospital Sendout to Cincinnati Children's Diagnostic Immunology Laboratory
Specimen Requirements
Patient Preparation: None
Container/Tube
Preferred/Acceptable: 4mL DkGrn NaHep (Sodium Heparin) tubes - (2 tubes needed)
Collection Volume: 10.0 mL
minimum volume required is dependent upon absolute lymphocyte count. Call Lab at 314-454-4268 for adjusted volume requirements or see "Cincinnati Children's Customized Volumes by ALC".
Submission Container/Tube: If specimen is coming from outside facility, send whole blood in original collection container. Keep specimen at ambient temperature only.
Special Instructions:
- Immediately invert tube gently 8-10 times after collection to ensure proper mixing of blood and anticoagulant (this will avoid specimen clotting).
- Forward promptly at ambient temperature.
- Complete a "Cincinnati Children's DIL test requistion form" to send with specimen.
Sample Rejection
Mislabeled or unlabeled specimens
Specimens collected in gel separater tubes
Specimens collected before 1000 a.m. or after 1630 Monday-Thursday
Specimens collected anytime Friday-Sunday or day of/before a holiday
Logistics
Test Availability: Monday-Thursday between 1000 a.m. & 1600 p.m. ONLY
Cut-off time: 1630
Days set up by performing lab: Monday-Friday
Turnaround Time: 4-6 days
Reference Values
Reference Interval: Interpretive report provided
Interpretive Data
Natural Killer (NK) cells are a subset of cytotoxic lymphocytes that have the ability to induce cell death in tumor cells or in virally infected cells. NK cells play a crucial role in the homeostasis of the immune system. They are typically characterized by the expression of CD16 and CD56 on their cell surface.
This assay makes use of the fact that NK cells will lyse the human erythroleukemia cell line, K562, in vitro. K562 cells are loaded with radioactive chromium and incubated with various ratios of a mononuclear cell preparation. Lysis of the K562 targets by NK cells contained in the cell preparation is measured by the amount of chromium released into the supernatant.
Critical Value: None established
Methodology
Chromium release
Limitations
- NA
Additional Information
FOR SLCH CORE LABORATORY USE ONLY
Lab Processing Instructions: DO NOT SPIN. Send specimen in original vacutainer. Send whole blood Monday-Thursday ONLY keeping specimen at ambient temperature.
Processed Volume: 10.0 mL (minimum volume dependent upon ALC). See CHH-DIL "Customized Volume by ALC" chart for volumes if needed.
Transport Temperature: Ambient
Analyte Stability:
| Specimen Type | Temperature | Time |
|---|---|---|
| Whole Blood (unprocessed) | Ambient | 28 hours |
| Refrigerated | Unacceptable | |
| Frozen | Unacceptable |
NOTE:
- ship specimen Monday-Thursday only, marking on outside of shipping box "STORE AT ROOM TEMPERATURE-DO NOT REFRIGERATE" and "DELIVER PROMPTLY UPON ARRIVAL".
- Please call/fax (513-636-4685/513-636-3861) the tracking number so they may better track specimen.
- Please call if a holiday falls during the week for increased testing restrictions.
- Call or fax CCH at:
- Phone: 513-636-4685
- Fax: 513-636-3861
- Call or fax CCH at:
- Send a completed "CCH-DIL test requistion" form with specimen.
- If patient has had Lymphocyte Subpopulation testing done, send report with specimen.
- Specimen MUST be received at CCH within 24 hours of collection (cancel if specimen collected before 0900 a.m. as specimen will not be received at CCH before 1000 a.m. the next day).
- Ship samples overnight to:
- CCHMC – Julie Beach
- DIL – Rm R2328 3333 Burnet Avenue
- Cincinnati, OH 45229
Test Classification and CPT Code
86352
86357
LOINC
- NK 50:1 82728-7
- NK 25:1 82727-9
- NK 12.5:1 82726-1
- NK 6.25:1 82725-3
- NK Lytic Unit 34439-0
- NK (CD16/56%) 8112-5
Last Reviewed
08/2025