Leukotriene E4, 24 Hour, Urine
Use
Quantitation of urinary metabolites of histamine, prostaglandin D2, and leukotriene E4 may provide significant clues for the diagnosis and management of symptomatic patients with both clonal and nonclonal mast cell activation syndromes. The presence of one or more elevated levels of these biomarkers in urine greatly narrows diagnostic possibilities, informs which metabolic pathways are involved, and enables personalized targeted treatment. The test is useful for evaluating patients at risk for mast cell activation syndrome (e.g., systemic mastocytosis, IgE‑mediated allergies, or aspirin‑exacerbated respiratory disease) using 24‑hour urine collections.
Special Instructions
For optimal evaluation, testing should be accompanied by serum tryptase, urinary 2,3‑dinor‑11‑beta‑prostaglandin F2 alpha (24‑hour), and urinary N‑methylhistamine (24‑hour). Random urine collections are preferred for episodic symptoms, in which case RLTE4 (Leukotriene E4, Random, Urine) should be ordered. Required information includes specimen volume and duration. Patients taking zileuton should discontinue it for 48 hours prior to collection. A plastic vial (Sarstedt Aliquot Tube, 5 mL) should be used; aliquot and send frozen.
Limitations
Patients taking the 5‑lipoxygenase inhibitor zileuton (Zyflo) may have decreased LTE4 concentrations, so discontinuation for 48 hours is recommended if medically feasible. The absence of elevated LTE4 does not exclude mast cell activation disease. Elevated LTE4 is nonspecific and should not be used alone for diagnosis.
New York Approved
Methodology
Mass Spectrometry (LC-MS/MS)
Biomarkers
LOINC Codes
- 101115-4
- 101115-4
- 2162-6
- 13362-9
- 3167-4
- 20624-3
Result Turnaround Time
2-9 days
Related Documents
For more information, please review the documents below
Specimen
Urine
Volume
5 mL
Minimum Volume
2 mL
Container
Plastic vial (Sarstedt Aliquot Tube, 5 mL)
Collection Instructions
Start collection within a few hours of symptom onset and collect urine for 24 hours; no preservative preferred; aliquot urine into a plastic vial and send frozen.
Patient Preparation
If medically feasible, discontinue zileuton for 48 hours prior to collection.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 24 hours |
| Refrigerated | 7 days |
| Frozen | 28 days |