Leukotriene E4, Urine, 24-hour

Message

Sendouts, Mayo test code: TLTE4

Test Code

LAB5211855

Alias/See Also

Cysteinyl Leukotriene
LTE4
Mast Cell Activation Syndrome
Mastocytosis
Systemic Mast Cell Activation
Secondary MCAS
Aspirin-exacerbated respiratory disease (AERD)
Asthma
IgE-dependent and independent asthma
Idiopathic MCAS
TLTE4

CPT Codes
82542

Preferred Specimen

5 mL urine collected from a 24-hour urine container.

Minimum Volume

2 mL

Other Acceptable Specimens

URINE PRESERVATIVE COLLECTION OPTIONS

Note: The addition of preservative or application of temperature controls must occur within 4 hours of completion of the collection.

Ambient	No
Refrigerate	Preferred
Frozen	OK
50% Acetic Acid	OK
Boric Acid	OK
Diazolidinyl Urea	No
6M Hydrochloric Acid	No
6M Nitric Acid	No
Sodium Carbonate	OK
Thymol	No
Toluene	No

Instructions

1. Start collection within a few hours of symptom onset and collect urine for 24 hours
2. No preservative preferred
3. Aliquot urine into a plastic vial and send frozen.

Transport Container

Plastic vial

Transport Temperature

Frozen

Specimen Stability

Frozen (preferred): 28 days
Refrigerated: 7 days
Ambient:24 hours

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

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Methodology
LTE4T: Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
CRT2F: Enzymatic Colorimetric Assay

FDA Status
Approved

Setup Schedule

Monday, Thursday

Report Available

2-9 days

Limitations

Patients taking the 5-lipoxygenase inhibitor zileuton (Zyflo) may have decreased concentrations of leukotriene E4 (LTE4) if the dosage has not been discontinued for 48 hours.

Mast cell (MC) activation disorder is a heterogenous disease, and the absence of elevated LTE4 does not exclude the diagnosis of MC disease.

Increased excretion of LTE4 is nonspecific and should not be used alone to make a clinical diagnosis of a MC activation disease.

This assay measures both LTE4 and the 11-trans-LTE4 as markers of MC release.

Reference Range

Included with report

Clinical Significance

Aiding in the evaluation of patients at-risk for mast cell activation syndrome (eg, systemic mastocytosis, IgE-mediated allergies, or aspirin-exacerbated respiratory disease) using 24-hour urine collections

Performing Laboratory
Mayo Clinic Laboratories, Rochester, Minnesota

Additional Information
Leukotriene E4, 24 Hour, Urine

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.