Non-invasive pathogen detection in the airways of patients with Cystic Fibrosis

In cystic fibrosis (CF), chronic infections with Pseudomonas aeruginosa (PA) and Staphylococcus aureus (SA) are associated with increased disease severity. Exhaled Volatile Organic Compounds (VOCs) have been suggested as a non-invasive biomarker for pathogen detection in respiratory disease (Kos, R. <italic>et al</italic>. J Cyst Fibros, 2022;21:e28-34). This observational study evaluated the potential of exhaled breath analysis using gas chromatography-mass spectrometry (GC-MS) as a tool for detecting PA and SA in patients with CF Complete data were available for 60 CF patients [mean age 22.2 years (+/- 14.1), 48% children, 59% homozygous ΔF508]. GC-MS analysis was used in combination with PLS-DA for discrimination between CF patients positive or free of PA and SA (same day), and chronic infection (Leeds criteria). Retaining VOCs were used in logistic regression analyses. Exhaled VOCs differed significantly between patients positive (9) or free (51) of PA, with (20) or without (40) chronic PA infection, positive (12) or free (48) of SA and with (32) or without (28) chronic SA infection. Models including respectively 2, 2, 1 and 4 VOCs were most predictive (figure 1). <fig><object-id>erj;64/suppl_68/PA2344/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig> By showing the discriminative power, this research contributes to clinical implementation of exhaled VOC analysis. Validation of these findings in independent cohorts with covariate correction is needed to evaluate the role of exhaled VOCs as biomarkers for pathogen detection in CF.