High levels of urinary leukotriene E 4 excretion in steroid treated patients with severe asthma

Abstract

Urinary LTE 4 reflects the whole body production of the cysteinyl-leukotrienes (LTC 4, LTD 4 and LTE 4) that are established mediators in asthma. The influence of chronic inhaled and oral glucocorticoid treatment on urinary excretion of leukotriene (LT) E 4 was investigated in subjects with asthma. Enzyme immunoassay analysis of LTE 4 was performed in spot urine samples collected from 40 patients with severe asthma, 25 patients with mild–moderate asthma and 20 non-asthmatic control subjects. Urinary LTE 4 was significantly higher in patients with severe asthma (69.7±5.5) as compared to mild–moderate asthma (45.7±3.3 with P<0.0004) and control (42.5±2.5 with P<0.0001). Despite chronic systemic treatment with glucocorticoids, chronically severe asthma had presented with higher levels of LTE 4 compared to mild–moderate asthma and healthy controls. The findings support previous indications that one important component in asthmatic airway inflammation, the cysteinyl-leukotriene pathway remains relatively unopposed by oral glucocorticoids.