The pivotal role of neutrophils and macrophages in smoking-related lung inflammation and COPD development is well-established.We aimed to assess whether sputum concentrations of Human Neutrophil Peptides (HNP), Neutrophil Elastase (NE), Interleukin-8 (IL-8), and Metalloproteinase-9 (MMP-9), major products of neutrophils and macrophages, could be used to trace airway inflammation and progression towards pulmonary functional impairment characteristic of COPD.Forty-two symptomatic smokers and 42 COPD patients underwent pulmonary function tests; sputum samples were collected at enrolment, and 6 months after smoking cessation. HNP, NE, IL-8, MMP-9 levels were increased in individuals with COPD ( p < 0.0001). HNP and NE concentrations were higher in patients with severe airways obstruction, as compared to patients with mild-to-moderate COPD ( p = 0.002). A negative correlation was observed between FEV 1 and HNP, NE and IL-8 levels ( p < 0.01), between FVC 1 /FVC and HNP, NE and IL-8 levels ( p < 0.01), and between NE enrolment levels and FEV 1 decline after 2 years ( p = 0.04). ROC analysis, to discriminate symptomatic smokers and COPD patients, showed the following AUCs: for HNP 0.92; for NE 0.81; for IL-8 0.89; for MMP-9 0.81; for HNP, IL-8 and MMP-9 considered together 0.981.The data suggest that the measurement of sputum markers may have an important role in clinical practice for monitoring COPD.
Paone, G., Conti, V., Vestri, A., Leone, A., Puglisi, G., Benassi, F., … Terzano, C. (2011). Analysis of sputum markers in the evaluation of lung inflammation and functional impairment in symptomatic smokers and COPD patients. Disease Markers, 31(2), 91–100. https://doi.org/10.3233/DMA-2011-0807