Gold nanoparticles and airway hyperreactivity.

We were delighted to read the article in the European Respiratory Journal by HUSSAIN et al. [1] which demonstrated aggravation of pulmonary inflammation and airway hyperreactivity by gold (Au) nanoparticles (NPs) in a mouse model of chemical-induced asthma. Exposure of sensitised (but not unsensitised) mice to Au NPs was shown to result in increased airway resistance and reactivity to methacholine, associated with Au NP uptake by macrophages, increased oedema and epithelial damage. Overall, these data are consistent with the idea of a potentially toxic, exacerbating effect of nebulised Au NPs within the airway, as discussed in the editorial accompanying the article [2].