Pulmonary Function Is Negatively Correlated With Sputum Inflammatory Markers and Cough Clearability in Subjects With Cystic Fibrosis But Not Those With Chronic Bronchitis

Evaluation of Thiol-Based Antioxidant Therapeutics in Cystic Fibrosis Sputum: Focus on Myeloperoxidase

“…Our observations with MPO were consistent with the reports of other investigators relating MPO levels to pulmonary function decrements in CF patients as a result of increased respiratory tract inflammatory processes (12,29,(36)(37)(38)(39)(40). Of note, the −463GA MPO promoter polymorphism, in which the GG phenotype is found to result in increased MPO gene expression in leukocytes, has been reported to be associated with a more aggressive loss of pulmonary function in CF (41).…”

Sputum Biomarkers of Inflammation and Lung Function Decline in Children with Cystic Fibrosis

“…Although the Mayer-Hamblett study (12) relied on spontaneously expectorated sputum samples (not induced) collected mainly from adolescents and adults with more advanced lung disease than the subjects in our study cohort, their results are reasonably comparable to our study findings in terms of concentrations of sputum inflammatory mediators and the outcome of a longitudinal association between FEV 1 and neutrophil elastase. In a single-center study of older subjects with CF with worse lung function than that in our study cohort, changes in sputum DNA concentrations (but not IL-8 or myeloperoxidase concentrations) at two discrete time points within 1 year correlated with changes in lung function (21). Another study that used bronchoalveolar lavage (BAL) rather than sputum to investigate the long-term effect of recombinant human DNase on inflammation in a study cohort similar to ours (mainly children with CF with mild lung disease), reported a significant increase in BAL biomarkers of airway inflammation (neutrophil counts, free neutrophil elastase, and IL-8) in untreated subjects, whereas levels of these biomarkers remained relatively unchanged in patients treated with DNase (22).…”

Sputum Biomarkers of Inflammation in Cystic Fibrosis Lung Disease

“…There is limited yet compelling evidence from small single-center studies supporting an association between sputum biomarkers and disease status in CF, defined either by pulmonary function measurements (109,111,115,(126)(127)(128)(129), chest radiograph scores (112,116), quality-of-life measures (114), or illness severity scores (e.g., Shwachman-Kulczycki score) (89). Sagel and coworkers have shown significant correlations between FEV 1 and a number of induced sputum inflammatory measures, including neutrophil counts, IL-8, neutrophil elastase, and matrix metalloproteinase (MMP)-9 in clinically stable children with CF with normal to mildly abnormal lung function (126,128).…”