Urinary leukotriene E₄ and 11-dehydro-thromboxane B₂ excretion in children with bronchial asthma

Abstract

Background: Cysteinyl leukotrienes (CysLTs) and thromboxane (TX) A₂ have been implicated in the pathogenesis of bronchial asthma. Urinary leukotriene E₄ (LTE₄) and 11-dehydro-TXB₂ (11DTXB₂) levels are often used to assess the production of CysLTs and TXA₂. However, few studies have examined the products of these two mediators in the same asthmatic patients. To define the potential roles of CysLTs and TXA₂ in the pathogenesis of bronchial asthma in children, their urinary levels were measured in the present study.
Methods: Urinary LTE₄ and 11DTXB₂ levels were measured by enzyme immunoassay (EIA) and radioimmunoassay (RIA), respectively. Urine samples from asthmatic children were measured during the stable condition and during an acute attack.
Results: Urinary LTE₄ levels during an acute attack (median 476 pg/mg creatinine; range 191-1100 pg/mg creatinine) and during the stable condition (median 332 pg/mg creatinine; range 128-965 pg/mg creatinine) were significantly higher (P<0.05) than those of controls (median 233 pg/mg creatinine; range 103-389 pg/mg creatinine). Urinary 11DTXB₂ levels during an acute attack and during the stable condition (median 1666 (range 110-5105) and 1009 (range 46-6070) pg/mg creatinine, respectively) were significantly higher (P<0.05) than those of controls (median 252 pg/mg creatinine; range 41-716 pg/mg creatinine). Comparing different stages of asthma, LTE₄ levels during an acute attack were significantly higher (P<0.05) than during the stable condition; however, there was no difference in urinary TXB₂ levels.
Conclusions: The present findings suggest that high levels of CysLTs and TXA₂ are associated with the pathogenesis of bronchial asthma. The measurement of urinary LTE₄ and 11DTXB₂ would be useful in understanding the individual pathogenesis of asthmatic children.