Leukotriene E4 (LTE4), Random Urine (Sendout)

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).
• Increased excretion of LTE4 is nonspecific and should not be used alone to make a clinical diagnosis of a MC activation disease.

Test Highlights: 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 1 or more elevated levels of these biomarkers in urine greatly narrows diagnostic possibilities for causes of symptoms, informs the practitioner what specific metabolic pathways are involved, and targets the treatment in a specific, personalized fashion.

For an optimal evaluation, testing for urinary leukotriene E4 should be accompanied with laboratory investigations for the presence of serum Tryptase [TRYPT], urinary 2,3-dinor 11 beta-prostaglandin F2 alpha (OLTG #692) and urinary N-methylhistamine (OLTG #478).

Systemic mastocytosis is a heterogenous disease and lack of elevated LTE4 does not exclude the diagnosis of mast cell disease.

Increased excretion of LTE4 has also been reported in the following conditions: asthma, eosinophilic pneumonia, respiratory syncytial virus infection, atopic dermatitis, Crohn disease, and rheumatoid arthritis.

Ordering Requirements: Pre-approved for UW Medicine Allergy Clinics. Orders from other locations require Laboratory Medicine Resident (LMR) approval.

Ordering Note: This test is for random urine collections only. For timed collections, refer to separate test Leukotriene E4, 24 Hour Urine (Sendout) [RULTE4].