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HelpOrder Code TLTE4 Leukotriene E4, 24 Hour, Urine
Ordering Guidance
Random urine collections are preferred for patients with episodic symptoms, (eg, in the context of allergic reactions brought on by specific environmental factors or mast cell activation syndrome). For random urine collection, order RLTE4 / Leukotriene E4, Random, Urine.
Additional Testing Requirements
For an optimal evaluation, testing for urinary leukotriene E4 should be accompanied with laboratory investigations for the presence of serum tryptase (TRYPT / Tryptase, Serum), urinary 2,3-dinor 11 beta-prostaglandin F2 alpha (23BPT / 2,3-Dinor 11 Beta-Prostaglandin F2 Alpha, 24 Hour, Urine) and urinary N-methylhistamine (NMH24 / N-Methylhistamine, 24 Hour, Urine).
Necessary Information
Specimen volume (in milliliters) and duration are required.
Specimen Required
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Container/Tube: Plastic vial
Specimen Volume: 5 mL
Collection 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.
Additional Information: See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens for multiple collection.
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 24-hour urine collections
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| LTE4T | Leukotriene E4, 24 Hr, U | No | Yes |
| CRT2F | Creatinine, 24 HR, U | No | Yes |
Special Instructions
Method Name
LTE4T: Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
CRT2F: Enzymatic Colorimetric Assay
Reporting Name
Leukotriene E4, 24 Hr, USpecimen Type
UrineSpecimen Minimum Volume
2 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Urine | Frozen (preferred) | 28 days |
| Refrigerated | 7 days | |
| Ambient | 24 hours |
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Reference Values
LEUKOTRIENE E4:
≤104 pg/mg creatinine
CREATININE:
Normal values mg per 24 hours:
Males: 930-2955 mg/24 hours
Females: 603-1783 mg/24 hours
Reference values have not been established for patients who are younger than 18 years of age.
Method Description
Leukotriene E4:
The specimen and an internal standard are assayed by liquid chromatography tandem mass spectrometry(LC-MS/MS). The analyte is detected by multiple-reaction monitoring.(Lueke AJ, Meeusen JW, Donato LJ, Gray AV, Butterfield JH, Saenger AK: Analytical and clinical validation of an LC-MS/MS method for urine leukotriene E4: A marker of systemic mastocytosis. Clin Biochem. 2016;49(13-14):979-982)
Creatinine:
This enzymatic method is based on the determination of sarcosine from creatinine with the aid of creatininase, creatinase, and sarcosine oxidase. The liberated hydrogen peroxide is measured via a modified Trinder reaction using a colorimetric indicator. Optimization of the buffer system and the colorimetric indicator enables the creatinine concentration to be quantified both precisely and specifically.(Package insert: Creatinine plus ver 2. Roche Diagnostics; V15.0, 03/2019)
Day(s) Performed
Monday, Tuesday, Thursday
Performing Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
82542