- Browse by Author
Browsing by Author "Johnson, Robin C."
Now showing 1 - 3 of 3
Results Per Page
Sort Options
Item Association of Lung Function, Chest Radiographs and Clinical Features in Infants with Cystic Fibrosis(European Respiratory Society, 2013) Rosenfeld, Margaret; Farrell, Philip M.; Kloster, Margaret; Swanson, Jonathan O.; Vu, Thuy; Brumback, Lyndia; Acton, James D.; Castile, Robert G.; Colin, Andrew A.; Conrad, Carol K.; Hart, Meeghan A.; Kerby, Gwendolyn S.; Hiatt, Peter W.; Mogayzel, Peter J.; Johnson, Robin C.; Davis, Stephanie D.; Pediatrics, School of MedicineThe optimal strategy for monitoring cystic fibrosis lung disease in infancy remains unclear. Our objective was to describe longitudinal associations between infant pulmonary function tests, chest radiograph scores and other characteristics. Cystic fibrosis patients aged ≤24 months were enrolled in a 10-centre study evaluating infant pulmonary function tests four times over a year. Chest radiographs ∼1 year apart were scored using the Wisconsin and Brasfield systems. Associations of infant pulmonary function tests with clinical characteristics were evaluated with mixed effects models. The 100 participants contributed 246 acceptable flow/volume (forced expiratory volume in 0.5 s (FEV0.5) and forced expiratory flow at 75% of the forced vital capacity (FEF75%)), 303 functional residual capacity measurements and 171 chest radiographs. Both Brasfield and Wisconsin chest radiograph scores worsened significantly over the 1-year interval. Worse Wisconsin chest radiograph scores and Staphylococcus aureus were both associated with hyperinflation (significantly increased functional residual capacity), but not with diminished FEV0.5 or FEF75%. Parent-reported cough was associated with significantly diminished forced expiratory flow at 75% but not with hyperinflation. In this infant cohort in whom we previously reported worsening in average lung function, chest radiograph scores also worsened over a year. The significant associations detected between both Wisconsin chest radiograph score and S. aureus and hyperinflation, as well as between cough and diminished flows, reinforce the ability of infant pulmonary function tests and chest radiographs to detect early cystic fibrosis lung disease.Item Infant lung function tests as endpoints in the ISIS multicenter clinical trial in cystic fibrosis(Elsevier, 2016-05) Davis, Stephanie D.; Ratjen, Felix; Brumback, Lyndia C.; Johnson, Robin C.; Filbrun, Amy G.; Kerby, Gwendolyn S.; Panitch, Howard B.; Donaldson, Scott H.; Rosenfeld, Margaret; Department of Pediatrics, IU School of MedicineBACKGROUND: The Infant Study of Inhaled Saline (ISIS) in CF was the first multicenter clinical trial to utilize infant pulmonary function tests (iPFTs) as an endpoint. METHODS: Secondary analysis of ISIS data was conducted in order to assess feasibility of iPFT measures and their associations with respiratory symptoms. Standard deviations were calculated to aid in power calculations for future clinical trials. RESULTS: Seventy-three participants enrolled, 70 returned for the final visit; 62 (89%) and 45 (64%) had acceptable paired functional residual capacity (FRC) and raised volume measurements, respectively. Mean baseline FEV0.5, FEF75 and FRC z-scores were 0.3 (SD: 1.2), -0.2 (SD: 2.0), and 1.8 (SD: 2.0). CONCLUSIONS: iPFTs are not appropriate primary endpoints for multicenter clinical trials due to challenges of obtaining acceptable data and near-normal average raised volume measurements. Raised volume measures have potential to serve as secondary endpoints in future clinical CF trials.Item Progression of Lung Disease in Preschool Patients with Cystic Fibrosis(American Thoracic Society, 2017-05-01) Stanojevic, Sanja; Davis, Stephanie D.; Retsch-Bogart, George t; Webster, Hailey; Davis, Miriam; Johnson, Robin C.; Jensen, Renee; Pizarro, Maria Ester; Kane, Mica; Clem, Charles C.; Schornick, Leah; Subbarao, Padmaja; Ratjen, Felix A.; Pediatrics, School of MedicineRATIONALE: Implementation of intervention strategies to prevent lung damage in early cystic fibrosis (CF) requires objective outcome measures that capture and track lung disease. OBJECTIVES: To define the utility of the Lung Clearance Index (LCI), measured by multiple breath washout, as a means to track disease progression in preschool children with CF. METHODS: Children with CF between the ages of 2.5 and 6 years with a confirmed diagnosis of CF and age-matched healthy control subjects were enrolled at three North American CF centers. Multiple breath washout tests were performed at baseline, 1, 3, 6, and 12 months to mimic time points chosen in clinical care and interventional trials; spirometry was also conducted. A generalized linear mixed-effects model was used to distinguish LCI changes associated with normal growth and development (i.e., healthy children) from the progression of CF lung disease. MEASUREMENTS AND MAIN RESULTS: Data were collected on 156 participants with 800 LCI measurements. Although both LCI and spirometry discriminated health from disease, only the LCI identified significant deterioration of lung function in CF over time. The LCI worsened during cough episodes and pulmonary exacerbations, whereas similar symptoms in healthy children were not associated with increased LCI values. CONCLUSIONS: LCI is a useful marker to track early disease progression and may serve as a tool to guide therapies in young patients with CF.