Assessment of hydrogen peroxide in breath condensate as an inflammatory marker in asthmatic children

Abstract

Background: Asthma is a major global public health problem. Airway  inflammation is the primary cause of development and progression of asthma. Activation of inflammatory cells induces a respiratory burst resulting in the production of reactive oxygen species, such as H₂O₂.
Objective: We sought to measure the concentration of H₂O₂ in exhaled breath condensate in asthmatic children and its correlation to asthmatic triggers, pulmonary function tests, treatment modalities and blood  absolute white blood cell counts.
Methods: Fifty asthmatic and 35 healthy children were studied. Their ages ranged from 3-14 years. Exhaled H₂O₂ was measured using a colorimetric assay.
Results: In asthmatic children, there was a significant elevation of the mean H₂O₂ concentration compared to values in normal subjects( p<0.0001). Bad housing showed significant correlation to asthma severity and to number of acute asthmatic attacks. Basal spirometric pulmonary function tests, mean values showed no significant correlation to the level of H₂O₂ nor to treatment with inhaled steroids. Similarly, neither asthma severity nor the intake of inhaled steroids did show any significant correlation with H₂O₂ level.
Conclusion: Exhaled H₂O₂ was found significantly elevated in asthmatic children. Measurement of exhaled H₂O₂ may help to assess airway inflammation and oxidative stress in asthmatic patients.

Keywords: Hydrogen peroxide – H₂O₂ – exhaled breath condensate – asthma – children – oxidative stress – pulmonary function tests.