Comparison of two methods for exhaled breath condensate collection.
BACKGROUND
Exhaled breath condensate (EBC) is a noninvasive method to obtain samples from fluids lining the respiratory surfaces. Even though various methods and devices are now available, the relative efficiency of these methods for recovering airway mediators and characterizing EBC has not been established.


OBJECTIVE
To compare the volume, pH, lipid mediator, and protein concentrations in EBCs collected by two commonly used commercially available devices, RTube and ECoScreen.


METHODS
Exhaled breath condensates were obtained consecutively using the RTube and ECoScreen methods from 30 healthy, nonallergic adults. Samples were immediately placed on dry ice after collection. pH was measured after argon deaeration. Cysteinyl leukotrienes (cys-LTs) were measured as a representative lipid mediator and eotaxin as the protein mediator by using enzyme-linked immunosorbent assay.


RESULTS
The mean volume of samples obtained with ECoScreen (1880 +/- 116 microl) was significantly higher than that obtained with RTube (1405 +/- 82 microl) (P < 0.001). Concentrations of both cys-LTs [205.4 pg/ml (65.5-472.3) with ECoScreen vs 21.6 (11.87-152.2) with RTube, P < 0.001] and eotaxin [17.0 pg/ml (11.4-22.4) with ECoScreen vs 11.7 (10.5-13.5) with RTube, P = 0.01] were significantly higher in samples collected with ECoScreen than with RTube. There was no significant difference between the pH measurements.


CONCLUSIONS
Compared with RTube, collection of exhaled breath by ECoScreen allows larger volumes to be collected and detects protein and lipid mediators with greater sensitivity. These differences in mediator recovery may be due to the differences in the collection temperature.
Soyer
O U
OU
Pediatric Allergy and Asthma Unit, Hacettepe University School of Medicine, Hacettepe, Ankara, Turkey.
Dizdar
E A
EA
Keskin
O
O
Lilly
C
C
Kalayci
O
O
D000328:Adult; D001944:Breath Tests / Q000295:instrumentation / Q000379:methods; D054413:Chemokine CCL11; D019742:Chemokines, CC / Q000032:analysis*; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D015289:Leukotrienes / Q000032:analysis*; D008297:Male; D013048:Specimen Handling / Q000295:instrumentation / Q000379:methods
C515456:CCL11 protein, human; D054413:Chemokine CCL11; D019742:Chemokines, CC; D015289:Leukotrienes