Breath condenser coatings affect measurement of biomarkers in exhaled breath condensate

Exhaled breath condensate collection is not yet standardized. Biomarker measurements are often close to lower detection-limits. We hypothesized that adhesive properties of different condenser coatings interfere with measurements of eicosanoids and proteins in condensate.In vitro, condensate was derived from a collection-model using two test solutions (8-isoprostane, albumin) and five condenser coatings respectively (silicone, glass, aluminum, polypropylene, teflon). In vivo, condensate was collected using these five coatings and the EcoScreen((R))-condenser to measure 8-isoprostane, and three coatings (silicone, glass, EcoScreen((R))) to measure albumin.In vitro, silicone and glass coatings had significantly higher albumin recovery compared with the other coatings (p=0.03). A similar trend was observed for 8-isoprostane recovery (p=0.09). In vivo, median (interquartile range) 8-isoprostane concentrations were significantly higher using silicone (9.2 pg.ml(-1) (IQR:18.8), p<0.001) or glass (3.0 pg.ml(-1) (IQR:4.5), p<0.02) coating compared with aluminum (0.5 pg.ml(-1), IQR:2.4), polypropylene (0.5 pg.ml(-1), IQR:0.5), teflon (0.5 pg.ml(-1), IQR:0.0), and EcoScreen((R)) (0.5 pg.ml(-1), IQR:2.0). Albumin in vivo was mainly detectable using glass coating (p<0.008). In conclusion, a condenser with silicone or glass coating is more efficient for measurement of 8-isoprostane or albumin in exhaled breath condensate, than EcoScreen((R)), aluminum, polypropylene or teflon. Guidelines for exhaled breath condensate standardization should include the most valid condenser coating to measure a specific biomarker. LA - ENG PT - JOURNAL ARTICLE DEP - 20060726 TA - Eur Respir J JID - 880346