Neutrophil Chemotaxis
Test Code
CHTX
Description
The innate and adaptive immune responses work in concert to protect the body against infection. The innate response is the first line of defense against microbial infection and involves a complex system of chemical messages produced by the microorganism and the injured tissues or by components of the Complement system. Neutrophils, a type of white blood cell (WBC) are attracted to the area of invasion or infection by these messages (a process called chemotaxis) where they engulf and destroy the organism (phagocytosis).
This assay measures the ability of the patient’s neutrophils to respond to a chemotactic stimulus (Complement component C5a) by migrating through a filter. Normal serum is activated by zymosan, a component of yeast, to produce C5a, which attracts the cells. The migration distance of the neutrophils through the filter is measured as compared to cells obtained from a normal donor.
Genetic conditions involving neutrophil dysfunction are rare but life threatening, with affected patients presenting with recurrent bacterial or fungal infections. Several of these deficiencies, such as Chronic Granulomatous Disease (CGD), Wiskott Aldrich Syndrome (WAS), Severe Congenital Neutropenia 4 (SCN4) and Neutrophil Immunodeficiency Syndrome (Rac2) among others, affect migration of neutrophils through the tissues to the site of infection.
Collect
One green top tube (Sodium or Lithium Heparin).
Additionally, if possible, draw and send a similar sample from an unrelated, normal subject to serve as a control.
Patient Prep
Preferred volume: 10 mL serum
Pediatric Collection
Minimum volume: 6 mL blood
Unacceptable Conditions
Frozen, clotted, hemolyzed or centrifuged specimens. Anticoagulants other than heparin. Specimens >24 hrs old.
Storage Transport Temp
Maintain and transport specimens at room temperature (18-22°C).
Ship specimens Priority Overnight via Fed Ex in container sufficiently insulated to avoid temperature extremes (<10°C and >37°C).
Stability
24 hours at room temperature (18-22°C)
Notes
Test must be scheduled with the laboratory at least one week in advance of draw. Please call ADx Client Services at 800.550.6227 to schedule testing.
Specimen must be received in the laboratory within 24 hours of collection.
Reference Interval
Buffer: 24-54 microns migrated, Zymosan Activated Serum (ZAS): 68-114 microns migrated.
Interpretation
This test assesses the ability of neutrophils to migrate in response to a chemoattractant and is useful in the assessment of suspected neutrophil defects.
CPT Code
86155 x2
New York Approved
No: Run with Waiver
FDA
LDT