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HelpTest Code RLTE4 Leukotriene E4, Random, 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).
Additional Testing Requirements
For an optimal evaluation, testing for urinary leukotriene E4 should be accompanied by laboratory investigations for the presence of serum tryptase (TRYPT / Tryptase, Serum), urinary 2,3-dinor 11 beta-prostaglandin F2 alpha (23BPR / 2,3-Dinor 11 Beta-Prostaglandin F2 Alpha, Random, Urine) and urinary N-methylhistamine (NMHR / N-Methylhistamine, Random, Urine).
Specimen Required
Patient Preparation: Patients taking 5-lipoxygenase inhibitor zileuton (Zyflo) may have decreased concentrations of leukotriene E4. If medically feasible, the patient should not take zileuton for 48 hours before specimen collection.
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Container/Tube: Plastic vial
Specimen Volume: 5 mL
Collection Instructions:
1. Within a few hours of symptom onset, collect a random urine specimen.
2. No preservative.
3. Aliquot urine into a plastic vial and send frozen.
Useful For
Aiding in the evaluation of patients at-risk for mast cell disorders (eg, systemic mastocytosis, IgE-mediated allergies, or aspirin-exacerbated respiratory disease) using random urine collections
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| LTE4R | Leukotriene E4, Random, U | No | Yes |
| CRTFR | Creatinine, Random, U | No | Yes |
Method Name
LTE4R: Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
CRTFR: Enzymatic Colorimetric Assay
Reporting Name
Leukotriene E4, Random, USpecimen Type
UrineSpecimen Minimum Volume
3 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Urine | Frozen (preferred) | 28 days |
| Refrigerated | 72 hours | |
| Ambient | 8 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
<18 years: Not established
≥18 years: 16-326 mg/dL
Day(s) Performed
Monday, Tuesday, Thursday
Report Available
2 to 9 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
82542
82570
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| RLTE4 | Leukotriene E4, Random, U | 33343-5 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 603457 | Leukotriene E4, Random, U | 33343-5 |
| CRTFR | Creatinine, Random, U | 2161-8 |