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Test Code RLTE4 Leukotriene E4, Random, Urine

Important Note

This test is only orderable by the laboratory.  To request this test in EPIC, please order LAB001 MAYO MISCELLANEOUS TEST.  Fill out appropriate prompts and request the Mayo test code listed above.

If you need further assistance, please contact the laboratory at 406-414-5010.


Ordering Guidance


Patients with mast cell activation syndrome may have chronically elevated leukotriene E4 (LTE4), however, in certain situations LTE4 can exhibit intermittent elevations. In these cases, a 24-hour urine collection is preferred. For 24-hour urine collection, order TLTE4 / Leukotriene E4, 24 Hour, 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 (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 (LTE4). 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 activation syndrome (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

Specimen Type

Urine

Specimen 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

<18 years: Not established

≥18 years: 16-326 mg/dL

Day(s) Performed

Monday, Tuesday, Thursday

Report Available

2 to 9 days

Performing 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