Update Type: Test Code Change
Test Updated: 02/02/2022
Test Overview
Test Methodology
LTE4: Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
AACT: Enzymatic Colorimetric Assay
Test Usage
Evaluating patients suspected of having systemic mastocytosis
Identification of aspirin sensitivity in patient respiratory diagnoses
Reference Range *
< or equal to 104 pg/mg creatinine
Test Limitations
Patients taking 5-lipoxygenase inhibitor Zileuton/Zyflo may have decreased concentrations of leukotriene E4 (LTE4) if dosage has not been discontinued for 48 hours. If possible, discontinue for 48 hours before testing.
Test Details
Days Set Up
Tuesday, Friday
Analytic Time
3 - 9 days
Soft Order Code
RLTE4 (random) or TLTE4 (24 hour)
Laboratory
Sendout
Reference Laboratory
Mayo RLTE4 or TLTE4
Section
Special Testing
Specimen Requirements
Collection Instructions
Send urine in a plastic cup/container to Specimen Processing refrigerated with no preservative.
Alternate Specimen
Refrigeration is the preferred preservative. But acceptable others are: 50 % acetic acid, boric acid or sodium carbonate.
Normal Volume
4 mL
Minimum Volume
1 mL
Storage Temperature
Refrigerated preferred, frozen acceptable
Additional Information
Test sent to Mayo Clinic Laboratories.
Billing
CPT Code
82542
Fee Code
AA494
NY State Approved
No