Leukotriene E4, random urine

Alphabetical Test listing

Leukotriene E4, random urine-994

Test name:

Test number:

994

Excellian order number:

LAB994

Abbreviation:

MSO

Alternate names:

Cysteinyl Leukotriene
LTE4
Mast Cell Activation Syndrome
Mastocytosis
Systemic Mast Cell Activation
Idiopathic MCAS

Useful for:

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 random urine collections

Patient preparation information:

Patient should not take zileuton for 48 hours before specimen collection

Specimen type:

Urine, random

Collection container:

Screw cap plastic container (non sterile)

Volume:

5 mL

Minimum volume:

2 mL

Processing instructions:

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

Transport container:

Screw cap transfer vial/tube (Mayo T914)

Transport and stability:

Frozen (preferred) – 28 days

Refrigerated - 73 hours

Ambient - 8 hours

Performing lab:

Mayo Clinic Laboratories (RLTE4): R-NX

Days set up:

Mo, Tu, Th

TAT:

2 - 9 days

Method:

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

Reference ranges:

Leukotriene E4:

≤104 pg/mg creatinine

Creatinine (Normal values mg per 24 hours):

Male: 930 - 2955 mg/24 hours

Female: 603 - 1783 mg/24 hours

Cautions:

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:

09/14/2026

Review date:

07/31/2026