Exhaled eicosanoids following oral aspirin challenge in asthmatic patients

Abstract

Background: Biochemical analysis of expiratory breath condensate is an emerging non-invasive technique for assessment of airway inflammation.

Objective: We wondered whether application of expiratory breath condensate could facilitate diagnosis of aspirin-intolerant asthma and reproduce eicosanoids mediators' abnormalities described in this disease.

Methods: We measured prostaglandins (PGs) E(2), F(2 alpha), 9 alpha 11 beta F(2) and iso-F(2) by gas-chromatography/mass-spectrometry and cysteinyl leukotrienes (cys-LTs) by radioimmunoassay in breath condensates of asthmatic patients undergoing oral aspirin challenge. Fourteen patients with aspirin-induced asthma and 20 aspirin-tolerating asthmatics, most of them on chronic inhaled corticotherapy, were studied and compared with 10 healthy subjects. Additionally, plasma 9 alpha 11 beta PGF(2), the metabolite of PGD(2) and urinary leukotriene (LT) E(4) were measured before and following the challenge.

Results: At baseline, PG did not differ between the groups, except for lower 9 alpha 11 beta PGF(2) in aspirin-intolerant asthma. Their concentrations were not changed by the challenge. Breath condensate cys-LTs were similar in the groups studied at base, and after aspirin challenge increased only in aspirin-intolerant patients. Elevated baseline urinary LTE(4) and its further increase following aspirin challenge was highly diagnostic for aspirin-intolerant asthma. The discriminatory value of cys-LTs increase in breath condensates was lower (72.8%) than either basal (99%) or post-challenge increase (94%) of urinary LTE(4).

Conclusions: In asthmatic patients on chronic corticotherapy measurement of urinary LTE(4) excretion rather than cys-LTs in breath condensate is of greater value for diagnosis of aspirin hypersensitivity.