Urinary bromotyrosine measures asthma control and predicts asthma exacerbations in children.

Abstract

OBJECTIVES:

To determine the usefulness of urinary bromotyrosine, a noninvasive marker of eosinophil-catalyzed protein oxidation, in tracking with indexes of asthma control and in predicting future asthma exacerbations in children.

STUDY DESIGN:

Children with asthma were recruited consecutively at the time of clinic visit. Urine was obtained, along with spirometry, exhaled nitric oxide, and Asthma Control Questionnaire data. Follow-up phone calls were made 6 weeks after enrollment.

RESULTS:

Fifty-seven participants were enrolled. Urinary bromotyrosine levels tracked significantly with indexes of asthma control as assessed by Asthma Control Questionnaire scores at baseline (R = 0.38, P = .004) and follow-up (R = 0.39, P = .008). Participants with high baseline levels of bromotyrosine were 18.1-fold (95% CI 2.1-153.1, P = .0004) more likely to have inadequately controlled asthma and 4.0-fold more likely (95% CI 1.1-14.7, P = .03) to have an asthma exacerbation (unexpected emergency department visit; doctor's appointment or phone call; oral or parenteral corticosteroid burst; acute asthma-related respiratory symptoms) over the ensuing 6 weeks. Exhaled nitric oxide levels did not track with Asthma Control Questionnaire data; and immunoglobulin E, eosinophil count, spirometry, and exhaled nitric oxide levels failed to predict asthma exacerbations.

CONCLUSIONS:

Urinary bromotyrosine tracks with asthma control and predicts the risk of future asthma exacerbations in children.

• Authors: Samuel H Wedes, Weijia Wu, Suzy A A Comhair, Karen M McDowell, Joseph A DiDonato, Serpil C Erzurum, Stanley L Hazen
• Journal: The Journal of pediatrics (J Pediatr) Vol. 159 Issue 2 Pg. 248-55.e1 (Aug 2011) ISSN: 1097-6833 [Electronic] United States
• PMID: 21392781 (Publication Type: Comparative Study, Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2011 Mosby, Inc. All rights reserved.

Chemical References

• Biomarkers
• bromotyrosine
• Tyrosine

Topics

• Adolescent
• Asthma (physiopathology, urine)
• Biomarkers (urine)
• Child
• Child, Preschool
• Chromatography, High Pressure Liquid
• Female
• Follow-Up Studies
• Forced Expiratory Flow Rates
• Humans
• Male
• Predictive Value of Tests
• Prognosis
• Prospective Studies
• Recurrence
• Spirometry
• Time Factors
• Tyrosine (analogs & derivatives, urine)
• Young Adult