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.