Diagnosing diffuse parenchymal lung disease (DPLD) by non-invasive breath screening of exhaled volatile compounds using an electronic nose: a pilot study

Background:

The diffuse parenchymal lung diseases (DPLD) is a big group of pulmonary inflammatory and/or fibrosing diseases with diverse natural courses; some of them, i.e. idiopathic pulmonary fibrosis (IPF) are associated with high mortality rate. The patient's survival depends on timing of correct diagnosis. We conducted this single-center trial to evaluate, if a rapid, point-of-care, and easy-to-use diagnostic tool, such as the electronic nose Aeonose®, would be able to differentiate between DPLDs and healthy state.

Methods:

The electronic nose signatures of exhaled volatile compounds of 116 patients with DPLD were captured using the Aeonose® and compared to a cohort of 42 healthy subjects. Area under Curve (AUC) and Matthews correlation coefficient (MC) were used to interpret the Aeonose® data.

Results:

The Aeonose® was able to differentiate between IPF-patients (n = 62) and healthy controls, showing an AUC of 0.92 and MC of 0.71. In comparison between cryptogenic organizing pneumonitis (COP, n = 30) vs. healthy, an AUC of 0.86 and MC of 0.7 were obtained. In case of patients with connective tissue diseases – ILD (CT-ILD, n = 24) vs. healthy, an AUC of 0.89 and MC of 0.7 were encountered.

Conclusions:

Based on exhaled volatile compounds, the Aeonose® shows promising potential in capturing disease-specific signatures in IPF, COP or CT-ILD and may therefore be suited to improve the efficacy and accuracy of a specific diagnosis in ILDs. However, additional studies validating these results in a larger cohort and more complex, multivariate statistical analyses are necessary to further document the usefulness of this device.