Home
HelpTest Code 9000 Immune Cell Function Assay (ImmuKnow®)
Additional Codes
| Eurofins-Viracor Test ID |
|---|
| 9016 |
EPIC Order: Miscellaneous Lab Test (LAB000)
NOTICE
ImmuKnow is an immune cell function assay that detects cell-mediated immunity in an immunosuppressed population. The assay detects cell mediated immunity by measuring the concentration of ATP from CD4 cells following stimulation.
Performing Laboratory
St. Louis Children's Hospital Sendouts to Eurofins-Viracor
Specimen Requirements
Patient Preparation: None
Container/Tube
Preferred?Acceptable: Dark Green-top Sodium Heparin (DRKGRN NaHep) tube
Collection Volume: 2.0 mL (minimum 1.0 mL)
Submission Container/Tube: If specimen is coming from outside facility, send whole blood in original collection container STAT (specimen must be processed in SLCH core lab within 2 hours of collection.)
Special Instructions: Immediately invert tube gently 8-10 times after collection to ensure proper mixing of blood and anticoagulant (this will avoid specimen clotting). Send to lab promptly.
Sample Rejection
Mislabeled or unlabeled specimens
Clotted specimens
Specimens collected between the hours of 1600-0400 Monday-Friday or any specimen collected on a Saturday, Sunday, or day of/before a holiday.
Specimens collected in lithium heparin, ACD, Gel, or EDTA tubes.
Logistics
Test Availability: Monday-Friday between 0400-1600 ONLY!
Cut-off time: 1600
Turnaround Time: 36-48 hours from receipt in performing lab
Reference Values
Reference Interval:
Low immune response: ATP level ≤225 ng/mL.
Moderate immune response: ATP level 226-524 ng/mL.
Strong immune response: ATP level ≥525 ng/mL.
Results of the ImmuKnow assay should be used in conjunction with clinical presentation, medical history, and other clinical indicators when establishing the immune status of a patient. This is a qualitative assay; therefore, the result does not quantify the level of immunosuppression.
NOTE: The ATP level ranges for ImmuKnow were established by testing 155 apparently healthy adults and 127 transplant recipients. A cumulative frequency of differences was used to select the ATP levels that give the best balance of results between immunosuppressed and non-immunosuppressed individuals. The cutoffs for the ATP level ranges are 225 and 525 ng/mL.
Critical Value: None established
Methodology
ImmuKnow technology combines cell stimulation, cell selection, and quantification of metabolic markers (ATP) to measure cell-mediated immunity. ImmuKnow measures early response to stimulation by detecting intracellular ATP synthesis in CD4 cells selected from blood by monoclonal antibody-coated magnetic beads. The amount of ATP present in stimulated blood specimens is a measure of lymphocyte activity. Since the CD4 lymphocytes orchestrate cell-mediated immunity responses through immunoregulatory signaling, the measurement of CD4 activation reflects the degree of immune function.
Limitations
- Sensitivity: The limit of ATP detection of ImmuKnow is 1 ng/mL.
Additional Information
FOR SLCH CORE LABORATORY USE ONLY
Lab Processing Instructions: DO NOT SPIN Send in original collection tube
Processed Volume: 2.0 mL (minimum 1.0 mL) NaHep whole blood
Transport Temperature: Ambient
Analyte Stability:
| Specimen Type | Temperature | Time |
|---|---|---|
| Whole Blood (unprocessed) | Ambient | 30 hours |
| Refrigerated | unacceptable | |
| Frozen | unacceptable |
Ship Monday through Friday. Friday shipments must be labeled for Saturday delivery. A Eurofins-Viracor test requistion form must accompany each specimen.
Ship specimens FedEx Priority Overnight® to: Eurofins Viracor, 18000 W 99th St., Ste. #10, Lenexa, KS 66219
Test Classification and CPT Code
86352
Test Classification: This test has been cleared or approved for diagnostic use by the U.S. Food and Drug Administration.
LOINC
- NA
Last Reviewed
08/2025