Heparin-binding protein in sputum as a marker of pulmonary inflammation, lung function, and bacterial load in children with cystic fibrosis

Abstract

Background: Cystic fibros.000000 bacterial pulmonary infections and neutrophil-dominated inflammation in the airways. The aim of this study was to evaluate the neutrophil-derived protein Heparin-binding protein (HBP) as a potential sputum marker of airway inflammation and bacterial load. Methods: Nineteen CF patients, aged 6-18 years, were prospectively followed for 6 months with sputum sampling at every visit to the CF clinic. A total of 41 sputum samples were collected. Sputum-HBP was analysed with ELISA, neutrophil elastase activity with a chromogenic assay, and total bacterial load with RT-PCR of the 16 s rDNA gene. Data were compared to lung function parameters and airway symptoms. Results: HBP and elastase correlated to a decrease in FEV 1 %predicted compared to the patients' individual baseline pulmonary function (ΔFEV 1 ), but not to bacterial load. Area under the receiver operating characteristic curve values for the detection of > 10% decrease in ΔFEV 1 were 0.80 for HBP, 0.78 for elastase, and 0.54 for bacterial load. Conclusions: Sputum HBP is a promising marker of airway inflammation and pulmonary function in children with CF.