Mediator-specific methodological issues in exhaled breath condensate collection
| Mediator | Pattern of breathing | Oral contamination | Condenser coating |
| pH | No effect 12 | No effect 12 | EcoScreen > R-tube in asthma/allergic rhinitis/healthy 6R-tube = EcoScreen in healthy 7, 8 |
| LTB4 | No effect 16 | Salivary contamination 26 | |
| Cysteinyl-LTs | No effect 16 | EcoScreen > R-tube 7 | |
| PGE2 | No effect 16 | ||
| H2O2 | Inversely proportional 17 | ||
| 8-isoprostane | Silicone/glass highest concentrations 10 | ||
| Nitrate/nitrite | No effect 18 | Increased by oral nitrate load 25 | |
| Protein | No effect 18 | ||
| Albumin | Silicone/Glass highest concentrations 10 | ||
| Aldehydes | No effect 9 | R-tube = other device 9 | |
| Eotaxin | EcoScreen > R-tube 7 |
LT: leukotrine; PG: prostaglandin; H2O2: hydrogen peroxide. EcoScreen is manufactured by Jaeger, Wurzburg, Germany; R-tube: Respiratory Research Inc., Charlottesville, VA, USA.