RATIONALE: Sputum biomarkers of @entity281 and @entity32 are noninvasive measures that enable quantification of the complex pathophysiology of @entity9129 . Validation of these biomarkers as correlates of disease severity is a key step for their application. OBJECTIVES: We constructed a large database from four multicenter studies to quantify the strength of association between expectorated sputum biomarkers and FEV(1.) METHODS: FEV(1) (range, 25-120% predicted) and quantitative data on expectorated sputum biomarkers including free neutrophil elastase, @entity687 , neutrophils, @entity796 , and @entity794 were obtained from 269 @entity1 (ages, 9-54 years) from 33 centers. Cross-sectional and longitudinal statistical analyses were performed to estimate associations between the markers and FEV(1), including the use of multivariable analyses. RESULTS: Elastase was negatively correlated with FEV(1) (correlation [r] = -0.35; 95% confidence interval [CI]: -0.46, -0.22). On average, @entity1 with @entity1577 who differed in their elastase measurements by 0.5 log differed in their FEV(1) values by -7.3% (95% CI: -9.7, -4.6). Neutrophil counts and @entity687 were also each negatively correlated. In a multivariable regression, elastase and neutrophil counts were able to explain the majority of variation in FEV(1). Elastase was further shown to have a significant longitudinal association with FEV(1), specifically a -2.9% decline in FEV(1) (95% CI: -5.0, -0.9) per 1-log increase in elastase. Although correlated with FEV(1), bacterial densities were unable to explain clinically meaningful differences in FEV(1) within and across @entity1 . CONCLUSIONS: These data support the role of sputum biomarkers as correlates of disease severity in a diverse @entity1577 population.

Association between pulmonary function and sputum biomarkers in XXXX .

@entity1 :: ('9606', 'Species') :: ['participants', 'patients'] @entity32 :: ('MESH:D007249', 'Disease') :: ['inflammation'] @entity796 :: ('287', 'Species') :: ['Pseudomonas aeruginosa'] @entity1577 :: ('MESH:D003550', 'Disease') :: ['CF'] @entity794 :: ('1280', 'Species') :: ['Staphylococcus aureus'] @entity281 :: ('MESH:D007239', 'Disease') :: ['infection'] @entity687 :: ('3576', 'Gene') :: ['IL-8'] @entity9129 :: ('MESH:C563237', 'Disease') :: ['cystic fibrosis (CF) lung disease']
@entity1577 :: (MESH:D003550,Disease) :: ['cystic fibrosis']
