From the Author

From the author:

I would like to thank P. Rosias and coworkers for reading my editorial with great interest 1. It is clear from their letter that they agreed with the limitations of collection and assay methodologies used, and the reproducibility of the oxidative biomarkers in exhaled breath condensate (EBC), particularly in smokers described in the editorial 1. The question now arises as to whether home-made and/or commercial EcoScreen are valid for collection of EBC? This is an important question and certainly more research is needed to provide a clear-cut answer to a choice of assay method for a specific collection system. The home-made machine may vary from one laboratory to another but the EcoScreen condenser is at least being standardised and manufactured commercially and, therefore, will have constant degree of baseline limitations. It is understandable that oxidant biomarkers and proteins, such as albumin (which contains thiol groups), would be useful to collect EBC in an inert environment due to their high reactivity, whereas any metallic coating would be highly reactive with peroxides and thiol groups. Roisias et al. [3] have compared the influence of different inner condenser coating materials on the detection of human albumin but not for 8‐isoprostane in EBC. Nevertheless, online (real-time) measurements of oxidative stress biomarkers may resolve this controversial issue.

In light of the discussion above on collection, storage, analysis and reproducibility of exhaled breath condensate biomarkers, it is highly welcome and timely that the European Respiratory Society/American thoracic Society Task Force “Exhaled Breath Condensate” is due to publish its methodological recommendations in the European Respiratory Journal.