Hovold G, et al. - In this study involving cystic fibrosis (CF) patients, aged 6–18 years, researchers assessed the neutrophil-derived protein Heparin-binding protein (HBP) as a potential sputum marker of airway inflammation and bacterial load. They carried out a prospective 6 months follow- up in these subjects, with sputum sampling at every visit to the CF clinic. Using sputum samples, they analyzed sputum-HBP, neutrophil elastase activity and total bacterial load with ELISA, chromogenic assay, and RT-PCR (Real-Time Polymerase Chain Reaction) of the 16 s rDNA gene, respectively. Comparisons of data to lung function parameters and airway symptoms was performed. They found a correlation of HBP and elastase with a decrease in FEV₁%predicted (Forced expiratory volume in one second, % of predicted) vs the patients´ individual baseline pulmonary function (&DeltaFEV₁), but not with bacterial load. Overall, sputum HBP showed utility as a promising marker of airway inflammation and pulmonary function in children with CF.