Specimen type:  

Urine, random

Collection container:  

Screw cap plastic container (non sterile)

Volume:  

5 mL

Minimum volume:  

2 mL

Processing instructions:  

1. Transfer a 5 mL (minimum 2.0mL) aliquot to a Screw cap transfer vial/tube (Mayo T914), labeled as urine

Transport container:  

Screw cap transfer vial/tube (Mayo T914)

Transport and stability:  

Frozen (preferred) – 30 days

Refrigerated - 7 days

Ambient - 24 hours

Performing lab:  

Mayo Clinic Laboratories (RLTE4): R-NX

Days set up:  

Mo, Th

TAT:  

6 days

Method:  

Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS), Enzymatic Colorimetric Assay

Reference ranges:  

≤104 pg/mg creatinine

Cautions:  

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

Systemic mastocytosis is a heterogenous disease and lack of elevated LTE4 does not exclude the diagnosis of mast cell disease.

Increased excretion of LTE4 has also been reported in the following conditions: asthma, eosinophilic pneumonia, respiratory syncytial virus infection, atopic dermatitis, Crohn disease, and rheumatoid arthritis.

CPT codes:  

82542
82570

Date created:  

03/01/2022

Revised date:  

02/06/2023

Review date:  

03/01/2022