title: A Proof of Concept Study to Detect Urease Producing Bacteria in Lungs Using Aerosolized13C-Urea.
abstract: This is a "proof of concept" study to determine whether inhalation of13C-urea can be safely used to detect the presence of urease producing bacteria in the airways of patients with cystic fibrosis (CF) by detecting13CO2in breath. This was a prospective, 2-part, open label, single-center, single-arm, single-administration, dose-escalation investigational device exemption trial. First, the safety of 20 and 50 mg inhaled13C-urea was evaluated in 6 healthy adult participants. Then, 3 adult CF participants colonized withPseudomonas aeruginosawere enrolled for each dose of inhaled13C-urea. The safety of inhaled13C-urea was assessed by spirometry and physical examination.13C-urea was administered using a jet nebulizer, followed by serial spirometry (10 min and 30 min post inhalation) and collection of exhaled breath at 5, 10, and 15 min post inhalation. There was no clinical significant change in any of the spirometry values compared to baseline in healthy participants and CF patients. Mean of13CO2/12CO2delta over baseline (DOB) values in CF participants at 5, 10, and 15 min post inhalation was as follows: 20 mg dose 4‰ (2.2‰-4.9‰), 1‰ (1.0‰-1.4‰), and 1‰ (0.4‰-1.5‰); 50 mg dose: 10‰ (6.2‰-14.5‰), 3‰ (2.1‰-4.3‰), and 1.5‰ (0.6‰-2.3‰). Inhaled13C-urea for detection of urease producing bacteria was safe, and preliminary data suggest that13CO2/12CO2DOB values may be higher in CF patients withP. aeruginosaat 5-10 min after inhalation of13C-urea. A future direction is to investigate use of inhaled13C-urea in young children who have difficulty producing sputum for culturing.
authors.affiliation: Department of Pediatrics, School of Medicine, University of New Mexico , Albuquerque, New Mexico.
authors.forename: Hengameh H
authors.initials: HH
authors.lastname: Raissy
authors.affiliation: Department of Pharmaceutical Sciences, Health Sciences Center, College of Pharmacy, University of New Mexico , Albuquerque, New Mexico.
authors.forename: Graham
authors.initials: G
authors.lastname: Timmins
authors.affiliation: Department of Pediatrics, School of Medicine, University of New Mexico , Albuquerque, New Mexico.
authors.forename: Lea
authors.initials: L
authors.lastname: Davies
authors.affiliation: Department of Internal Medicine, Pulmonary and Critical Care, University of New Mexico , Albuquerque, New Mexico.
authors.forename: Theresa
authors.initials: T
authors.lastname: Heynekamp
authors.affiliation: Department of Pulmonary, Critical Care and Sleep Medicine, University of New Mexico , Albuquerque, New Mexico.
authors.forename: Michelle
authors.initials: M
authors.lastname: Harkins
authors.affiliation: Department of Earth & Planetary Sciences, University of New Mexico , Albuquerque, New Mexico.
authors.forename: Zachary D
authors.initials: ZD
authors.lastname: Sharp
authors.affiliation: Department of Pediatrics, School of Medicine, University of New Mexico , Albuquerque, New Mexico.
authors.forename: H William
authors.initials: HW
authors.lastname: Kelly