Effects of topical therapy on the breath pattern of patients with newly diagnosed COPD: An e-nose based study

Introduction: In COPD,pulmonary and systemic inflammation,hypoxemia and cellular oxidative stress contribute to shape the pattern of exhaled volatile compounds (VOCs).One of the technologies to assess this pattern, known as electronic nose (e-nose), has been proved able to identify breath patterns of COPD patients and to differentiate them from healthy controls and selected other pulmonary or systemic diseases. It is unknown whether an e-nose can detect changes in VOCs determined by topical therapy.We aimed at verifying whether the breath print of untreated COPD patients obtained by an e-nose differed after a 12 weeks treatment with a single inhaled bronchodilator or a combination of bronchodilator and steroid. Materials and methods: twenty-five recently diagnosed and untreated COPD patients underwent a multidimensional assessment and e-nose based breath print analysis. Patients were therefore prescribed a conventional inhaled regimen according to current international guidelines and re-evaluated after a 12 week therapeutic trial. Results: breathprints from COPD patients after treatment were correctly discriminated from baseline in 24 out of 25 (84%) while nine out of 25 (36%) baseline breathprints were erroneously classified as belonging to the post treatment group. The overall accuracy was 74%. Conclusions: changes of breath composition induced by topic medications in COPD was fairly able to identify the sample of treated individuals.This finding support the effect on inhaled medications on breathprint composition of COPD patients and the potential role of exhaled breath analysis for assessing compliance to treatment and monitoring the effect of medications in COPD.