CXCL9

Test Code

12063

CPT Codes
83520<br>Limited Access Code

Preferred Specimen

3 mL whole blood collected in an EDTA (lavender-top) tube - See Instructions

Minimum Volume

1 mL whole blood

Other Acceptable Specimens

0.3 mL plasma aliquot collected in two plastic leak-proof vials

Instructions

3 mL whole blood should be collected for each test using EDTA as an anticoagulant (lavender top tube).
Process and freeze separated plasma within 8 hours of collection. Freeze immediately at -20°C or lower. Ship on dry ice. Please refer to our requisition for sample collection and shipping instructions.

Whole blood must remain at room temperature at all times after collection until processed.
Separated plasma samples that have been frozen must be sent with enough dry ice to maintain a frozen state until received in our lab.

Transport Temperature

Whole blood: Room temperature
Plasma: Frozen

Specimen Stability

Whole blood
Room temperature: 8 hours
Refrigerated: Unacceptable
Frozen: Unacceptable

Plasma
Room temperature: Unacceptable
Refrigerated: Unacceptable
Frozen: 6 months

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Whole blood not processed within 8 hours of collection • Whole blood sent frozen • Blood collected in wrong container/tube type • Separated plasma sent room temperature or refrigerated

Methodology
Automated Microfluidics Immunoassay Method

FDA Status
This test was developed and its performance characteristics determined by the Cancer and Blood Diseases Institute Clinical Laboratories at CCHMC. It has not been cleared or approved by the FDA. This laboratory is regulated under CLIA as qualified to perform high-complexity clinical laboratory testing. This test is used for clinical purposes. It should not be regarded as investigational or for research.

Setup Schedule

Set up: Varies; Report available: 4 days

Reference Range

≤647 pg/mL

Clinical Significance

CXCL9, also known as monokine induced by gamma interferon (MIG), is a member of the CXC chemokine subfamily. CXC chemokines are known to recruit activated lymphocytes and hinder angiogenesis via CXCR3. CXCR3 is a transmembrane protein expressed on activated Th1 lymphocytes. It has been observed in monocytes, endothelial cells, eosinophils, malignant B cells, melanoma cells, CD34+ hematopoietic progenitors and neurons. Expression of CXCL9 is induced by the Th1 cytokine, IFN-gamma. This is dramatically enhanced by the addition of TNF-alpha. CXCL9 production has been proven to be a sensitive measure of antigen-specific IFN-gamma production. CXCL9 has been implicated in pathologies characterized by the accumulation of activated Th1 lymphocytes. These include acute allograft rejection, glomerulonephritis, autoimmunity, rheumatoid arthritis, atherosclerosis, psoriasis and allergic contact dermatitis.

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.