Clinical application of exhaled breath condensate analysis in asthma: prediction of FEV1 improvement by steroid therapy.
BACKGROUND
Exhaled breath condensate (EBC) measurements have recently been reported to be useful for the detection of inflammatory molecules in the airways. However, the clinical relevance of EBC analysis in asthma therapy has not been determined yet.


OBJECTIVE
To investigate whether EBC analysis has any potential for predicting the steroid response in asthmatics.


METHODS
Eighteen steroid-naive asthmatics were enrolled. EBC collection, spirometry and a methacholine challenge test were performed before and 12 weeks after inhaled steroid therapy. Exhaled IL-4, IL-17, RANTES, macrophage inflammatory protein (MIP)-1α, MIP-1β, IL-8, IFN-γ-inducible protein (IP)-10, TNF-α and TGF-β were simultaneously analyzed by a protein array, and the relationship between baseline molecule expression and steroid-mediated changes in forced expiratory volume in 1 s (FEV1) and airway responsiveness was investigated.


RESULTS
Steroid therapy improved FEV1 values and the methacholine threshold. Among the molecules examined, increased IL-4 and RANTES levels as well as decreased IP-10 levels at baseline were significantly correlated with an improvement in FEV1. By contrast, molecule levels were not related to changes in the responsiveness to methacholine. In addition, changes in FEV1 values were significantly associated with reductions in IL-4 and RANTES levels.


CONCLUSIONS
EBC measurements of IL-4, RANTES and IP-10 might be useful for predicting the steroid-mediated FEV1 improvement in asthma.
Third Department of Internal Medicine, Wakayama Medical University, School of Medicine, Wakayama 641-8509, Japan.
Kazuto
K
Matsunaga
Tomohiro
T
Ichikawa
Satoru
S
Yanagisawa
Keiichirou
K
Akamatsu
Akira
A
Koarai
Tsunahiko
T
Hirano
Hisatoshi
H
Sugiura
Yoshiaki
Y
Minakata
Masakazu
M
Ichinose
D058666:Adrenergic beta-2 Receptor Agonists / Q000627:therapeutic use; D000328:Adult; D000730:Androstadienes / Q000627:therapeutic use*; D001249:Asthma / Q000188:drug therapy* / Q000378:metabolism*; D001944:Breath Tests; D016085:Bronchoconstrictor Agents; D001993:Bronchodilator Agents / Q000627:therapeutic use*; D016207:Cytokines / Q000032:analysis / Q000378:metabolism*; D000068298:Fluticasone; D005541:Forced Expiratory Volume; D006801:Humans; D016210:Methacholine Chloride; D011237:Predictive Value of Tests
D058666:Adrenergic beta-2 Receptor Agonists; D000730:Androstadienes; D016085:Bronchoconstrictor Agents; D001993:Bronchodilator Agents; D016207:Cytokines; D016210:Methacholine Chloride; D000068298:Fluticasone