Safety and Yield of Exhaled Breath Condensate Analysis in Acutely Ill, Mechanically Ventilated Infants with RSV Bronchiolitis

Abstract

Exhaled breath condensate (EBC) analysis is a rapidly growing field of research and may be a useful non-invasive technique to evaluate lung pathology. There is little information in the literature on the safety of collecting these samples in acutely ill infants needing mechanical ventilation. Viral bronchiolitis is a common lower respiratory tract infection contributing to the majority of hospitalizations in children under 2 years of age. The pathophysiology of severe bronchiolitis resulting in ventilatory support is illdefined. Our study objective was to evaluate the tolerability of collection and utility of exhaled breath condensate (EBC) in molecular evaluation of viral bronchiolitis. We obtained proteomic profile of sequential EBCs over three days of illness from two infants who were intubated and ventilated. Mass spectrometry analysis of these samples identified cytokeratin at all time-points and time-dependent increase of proteins related to intracellular adhesions, epidermal morphogenesis, cell repair and differentiation that may be used to monitor the status of epithelial barrier function and integrity of intercellular communication in the bronchiolitis lung in the future. Our pilot study highlights that EBC collection is a well- tolerated procedure to obtain meaningful longitudinal data to profile and study the molecular parameters in acutely ill bronchiolitis infants.