Urinary leukotriene E₄ levels identify children with tobacco smoke exposure at risk for asthma exacerbation

J Allergy Clin Immunol. 2011 Aug;128(2):323-7. doi: 10.1016/j.jaci.2011.05.035.


Background: Children with asthma exposed to secondhand smoke (SHS) might be at higher risk for severe exacerbations, but biomarkers of susceptibility to SHS exposure have not been previously reported.

Objectives: We sought to assess the usefulness of urinary leukotriene E(4) (uLTE₄) levels in the prediction of increased risk of severe asthma exacerbations requiring emergency department (ED) or urgent care (UC) visits.

Methods: Forty-four schoolchildren with moderate-to-severe asthma receiving inhaled corticosteroids were followed for 5 months with repeated measurements of uLTE₄ and monitoring of ED and UC visits. SHS exposure status was determined by using prestudy questionnaires and repeated measurements of urinary cotinine during the study.

Results: Nine (45%) of 20 children with SHS exposure experienced a severe exacerbation requiring an ED or UC visit compared with 3 (12.5%) of 24 children without significant SHS exposure (relative risk, 3.6; 95% CI, 1.1-11.5; P = .02). The uLTE₄ level was a significant predictor of exacerbation risk in children exposed to SHS (area under the curve, 0.85; P = .003). Other predictors, such as nighttime symptom frequency, prebronchodilator and postbronchodilator lung function, and exhaled nitric oxide levels, were not related to exacerbations in this group. uLTE₄ levels at or greater than 106 pg/mg achieved 67% (6/9) sensitivity and 100% (11/11) specificity for predicting children with SHS exposure who required an ED or UC visit.

Conclusions: Children exposed to SHS are at increased risk for severe asthma exacerbations, despite use of inhaled corticosteroids. uLTE₄ levels identify children exposed to SHS at high risk for asthma exacerbations.

Publication types

  • Evaluation Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Administration, Inhalation
  • Adolescent
  • Asthma / chemically induced*
  • Asthma / drug therapy
  • Asthma / physiopathology*
  • Biomarkers / urine*
  • Child
  • Female
  • Humans
  • Leukotriene E4 / urine*
  • Male
  • Predictive Value of Tests
  • Risk
  • Severity of Illness Index
  • Surveys and Questionnaires
  • Tobacco Smoke Pollution / adverse effects*
  • Tobacco Smoke Pollution / statistics & numerical data


  • Biomarkers
  • Tobacco Smoke Pollution
  • Leukotriene E4