Clinical evaluation of urinary leukotriene E4 levels in asymptomatic bronchial asthma

To evaluate the significance of peptide leukotrienes (LTC4, D4, E4) in asymptomatic asthmatic patients, we measured urinary LTE4 levels which is thought to reflect in vivo production of peptide LTs. Urinary LTE4, was extracted using C18 solid phase column and measured by radioimmunoassay. There was no significant difference in urinary LTE4 levels among asthmatics with different severity or between atopic and non-atopic asthmatics. Urinary LTE4 levels were significantly elevated in asthmatics compared with normal controls (p < 0.05). When compared with normal controls, urinary LTE4 levels were significantly elevated in moderate to severe asthma (p < 0.05), and non-atopic asthmatics (p < 0.001). Urinary LTE4 levels were significantly elevated in aspirin-sensitive asthmatics compared with aspirin-tolerant asthmatics (p < 0.05). There was no significant difference in urinary LTE4 levels among aspirin-sensitive asthmatics with different severity. These results suggest that increased production of peptide LTs is a characteristic in aspirin-sensitive asthma, and that the severity and type of asthma and the presence of aspirin-sensitive asthma should be taken into consideration in the analysis of urinary LTE4 levels.