Use of exhaled hydrogen peroxide for asthma monitoring

Abstract

Exhaled hydrogen peroxide is a marker of airway inflammation. However, its utility for monitoring of asth­ma is still uncertain. The aim of this study was to assess the effect of short-acting β₂-agonists and inhaled steroids on the hydrogen peroxide (H₂0₂) concentration in expired breath condensate in asthmatic patients. Fifteen patients with moderate atopic asthma were treated with salbutamol as required for 2 weeks followed 12-week treatment with budesonide (Pulmicort Turbuhaler, 400 meg daily). The exhaled H₂0₂ concentration as measured using a colorimetric assay (Gallati&Pracht, 1985). FEV₁ was assessed using dry spirometer. Airway hyperresponsiveness was considered as a provocative concentration of inhaled histamine causing the 20%-fall in FEV₁ (PD₂₀).

The H₂0₂ baseline level in the asthmatic patients (0.19±0.03 μ‎M) was elevated compared to healthy sub­jects (0.028±0.003, p<0.001). The exhaled H₂0₂ concentration did not change during the treatment with salbutamol but it was diminished by Pulmicort Turbuhaler. This was associated with significant improvement in clinical symptom score, FEV₁ and PD₂₀ in asthma patients.

We conclude that the short-acting β₂-agonists do not influence the H₂0₂ concentration in the exhaled air condensate of the asthma patients but the inhaled steroids decrease it. This may reflect different anti-inflam­matory activities of these medications.