Background: The prognostic role of low sputum eosinophils in steroid-naïve, symptomatic asthmatic patients is controversial.
Aim: To verify whether low sputum eosinophils predict poor response to treatment with inhaled corticosteroids.
Methods: Sixty-seven symptomatic asthmatic patients with moderate asthma were examined before and after 2 weeks and 4 weeks of treatment with beclomethasone dipropionate, 500 microg bid. None received corticosteroids in the 3 months preceding the study. At each visit, all patients underwent spirometry, methacholine challenge, and sputum induction. The patients recorded symptom scores and peak expiratory flow (PEF) throughout the study.
Results: Seventeen patients had low sputum eosinophils despite being symptomatic. Patients with high (> 3%) sputum eosinophils at baseline showed significant improvement in symptoms, pulmonary function, and bronchial hyperresponsiveness after treatment, whereas patients with low sputum eosinophils showed no significant improvement in most clinical and functional outcomes. Among the baseline indexes examined, sputum eosinophils had the highest negative predictive value but low positive predictive value for the response to treatment. Multiple stepwise regression showed that only baseline FEV(1) and sputum eosinophil percentages significantly correlated with changes in FEV(1) after treatment.
Conclusions: We suggest that, among the indexes examined, low sputum eosinophils are the best predictor for poor corticosteroid effects in asthma.