Cysteinyl-leukotriens overproduction and the asthma severity in patients with aspirin-induced asthma

Background: The unique pathophysiology of aspirin-induced asthma (AIA) is cysteinyl-leukotriens (CysLT) overproduction. Almost patients with AIA show severe asthma, but some of them have mild asthma. The mechanisms underlying asthma severity in AIA patients remain unclarified. We hypothesized that CysLT overproduction is related to the asthma severity of AIA and tried to clarify the correlation between CysLT production and asthma severity in AIA patients.

Methods: Forty AIA patients, whose aspirin sensitivity was determined by the aspirin challenge test, and twenty healthy subjects participated in this study.  We measured urinary leukotrien E4 (U-LTE4) level under stable asthma condition, using Cayman’s EIA kit after purification by HPLC, as we reported previously. AIA patients were classified into three groups, 1) patients with mild to moderate asthma which was controlled at less than GINA Step 3 treatment,2) patients with stable but severe asthma which was well controlled at GINA Step 4 treatment, and  3) patients with difficult-to-treat asthma which was not controlled at GINA Step 4 treatment.

Results: The AIA groups 1-3 showed median U-LTE4 concentrations 108, 259, and 582 pg/mg creatinine, respectively. There was no significant difference between patients with mild to moderate asthma and healthy controls. On the other hand, the concentrations of U-LTE4 in patients with severe but stable AIA patients and difficult-to-treat AIA patients significantly increased according to asthma severity as compared with AIA patients with mild to moderate asthma.

Conclusion: CysLT overproduction may be related to the asthma severity in AIA patients.