Reproducibility and respiratory function correlates of exhaled breath fingerprint in chronic obstructive pulmonary disease.
BACKGROUND
The electronic nose (e nose) provides distinctive breath fingerprints for selected respiratory diseases. Both reproducibility and respiratory function correlates of breath fingerprint are poorly known.


OBJECTIVE
To measure reproducibility of breath fingerprints and to assess their correlates among respiratory function indexes in elderly healthy and COPD subjects.


METHODS
25 subjects (5 COPD patients for each GOLD stage and 5 healthy controls) over 65 years underwent e-nose study through a seven sensor system and respiratory function tests at times 0, 7, and 15 days. Reproducibility of the e nose pattern was computed. The correlation between volatile organic compound (VOC) pattern and respiratory function/clinical parameters was assessed by the Spearman's rho.


RESULTS
VOC patterns were highly reproducible within healthy and GOLD 4 COPD subjects, less among GOLD 1-3 patients.VOC patterns significantly correlated with expiratory flows (Spearman's rho ranging from 0.36 for MEF25% and sensor Co-Buti-TPP, to 0.81 for FEV1% and sensor Cu-Buti-TPP p<0.001)), but not with residual volume and total lung capacity.


CONCLUSIONS
VOC patterns strictly correlated with expiratory flows. Thus, e nose might conveniently be used to assess COPD severity and, likely, to study phenotypic variability. However, the suboptimal reproducibility within GOLD 1-3 patients should stimulate further research to identify more reproducible breath print patterns.
Chair of Geriatrics, Unit of Respiratory Pathophysiology, Campus Bio-Medico University, Rome, Italy.
Raffaele Antonelli
RA
Incalzi
Giorgio
G
Pennazza
Simone
S
Scarlata
Marco
M
Santonico
Massimo
M
Petriaggi
Domenica
D
Chiurco
Claudio
C
Pedone
Arnaldo
A
D'Amico
D000368:Aged; D001944:Breath Tests; D016022:Case-Control Studies; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology*; D015203:Reproducibility of Results; D055549:Volatile Organic Compounds / Q000032:analysis
D055549:Volatile Organic Compounds