Background In healthy children, there is a wide range in the induced sputum neutrophil differential count. To date, the reason for this is unclear. In animal models, neutrophil chemoattractant cytokines and oxidative stress are major determinants of airway neutrophilia. In this study, we therefore aimed to assess the association between interleukin-8, and the oxidative stress marker 8-oxo-7, 8-...