Urinary LTE4 levels identify children with tobacco smoke exposure at risk for asthma exacerbations

Published Online: August 1, 2011

Children with asthma exposed to secondhand tobacco smoke are at higher risk for severe exacerbations, but biomarkers of susceptibility to secondhand tobacco smoke exposure have not been previously reported.

In an upcoming issue of The Journal of Allergy and Clinical Immunology (JACI), Rabinovitch et al. report that measurement of urinary leukotriene E4 (uLTE4) can help predict increased risk of severe asthma exacerbations in children exposed to tobacco smoke. Forty-four schoolchildren with asthma receiving inhaled corticosteroids were followed for 5 months with repeated measurements of uLTE4.

Tobacco smoke exposure was determined by questionnaire and measurement of urinary cotinine. Mean uLTE4 levels were associated with severe exacerbations requiring urgent care in children exposed to tobacco smoke while other asthma severity predictors such as symptom frequency, lung function and exhaled nitric oxide levels were unrelated to severe exacerbations in this group. Two thirds of tobacco-smoke exposed children requiring urgent care had uLTE4 levels at or above 106 picograms per milligram while all of the smoke-exposed children who did not require urgent care had uLTE4 levels below this cut-off level.

This study suggests that uLTE4 may be utilized as a biomarker to identify children exposed to second hand tobacco smoke at high risk for severe asthma exacerbations despite use of controller therapies.


The Journal of Allergy and Clinical Immunology (JACI) is the official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.

AAAAI - American Academy of Allergy Asthma & Immunology