BAL fluid 8-isoprostane concentrations in eosinophilic bronchitis and asthma.

BACKGROUND

Oxidative stress has an important role in the pathophysiology of asthma. But oxidative stress of airway has not been assessed in patients with nonasthmatic eosinophilic bronchitis (EB). 8-epi-prostaglandin F2alpha (8-isoprostane) is a biomarker of oxidative stress.

OBJECTIVES

We sought to determine whether oxidative stress (measured by 8-isoprostane) occurs in EB and whether 8-isoprostane is associated with airway function in EB and asthma.

METHODS

We measured 8-isoprostane concentrations in the bronchoalveolar lavage (BAL) fluid from 11 subjects with EB, 10 subjects with asthma, and 9 healthy control subjects. 8-isoprostane was measured by enzyme immunoassays.

RESULTS

We found that BAL fluid 8-isoprostane concentrations were raised both in EB and asthma. The median concentrations of 8-isoprostane in BAL fluid were significantly higher in subjects with asthma (12.78 pg/mL) when compared with EB (8.34 pg/mL) and healthy control subjects (5.07 pg/mL).

CONCLUSIONS

Our study shows that oxidative stress is increased significantly in asthmatic subjects and the degree of oxidative stress in EB subjects is milder than that in asthma, as reflected by 8-isoprostane concentrations in the BAL fluid. The difference in airway function observed in subjects with EB and asthma could be associated with different elevation in 8-isoprostane concentration in the airways.