Are exhaled breath condensates useful in monitoring asthma?

Exhaled breath condensate (EBC) has emerged as a novel noninvasive technique for assessment of airway inflammation, and it also provides useful information on the airway lining fluid composition. Examples of markers that can be identified in the EBC of patients with asthma include pH, eicosanoids, nitrogen oxides and related products, markers of oxidative stress, certain cytokines, chemokines, and growth factors. There is some evidence that certain markers in EBC differ between patients with asthma and controls, and some markers may correlate with asthma severity and lung function, but there are many methodologic pitfalls with EBC assessment that limit its clinical applicability at present. More studies are needed before this technique can be recommended for clinical use.