ABSTRACT
This is a "proof of concept" study to determine whether inhalation of 13C-urea can be safely used to detect the presence of urease producing bacteria in the airways of patients with cystic fibrosis (CF) by detecting 13CO2 in 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 inhaled 13C-urea was evaluated in 6 healthy adult participants. Then, 3 adult CF participants colonized with Pseudomonas aeruginosa were enrolled for each dose of inhaled 13C-urea. The safety of inhaled 13C-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 of 13CO2/12CO2 delta 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). Inhaled 13C-urea for detection of urease producing bacteria was safe, and preliminary data suggest that 13CO2/12CO2 DOB values may be higher in CF patients with P. aeruginosa at 5-10 min after inhalation of 13C-urea. A future direction is to investigate use of inhaled 13C-urea in young children who have difficulty producing sputum for culturing.
ABSTRACT
Hemoglobin Chico is a rare hemoglobinopathy characterized by low oxygen affinity and a right-shifted oxygen dissociation curve. Detailed clinical evaluations of affected individuals have not been previously reported. We therefore report on the clinical features of Hemoglobin Chico in a Latino male living at high altitude, who desired to participate in school sports. As a young boy with asthma, he had the unusual finding of growth delay and digital clubbing which improved with asthma control. At 16 years of age, he had mild anemia and a decreased pulse oximetry (83%) but sufficient pulmonary reserve to participate in physically demanding activities.
