Analysis of Inflammatory and Immune Response Biomarkers in Sputum and Exhaled Breath Condensate by a Multi-Parametric Biochip Array in Cystic Fibrosis

Abstract

Cystic Fibrosis (CF) lung disease is characterized by high levels of cytokines and chemokines in the airways, producing chronic inflammation. Non-invasive biomarkers, which are also specific for the inflammatory and immune responses, are urgently needed to identify exacerbations and evaluate therapeutic efficacy. The aim of this study is to evaluate the association of sputum and exhaled breath condensate (EBC) biomarker changes with clinical exacerbation and response to therapy. We studied the simultaneous presence and concentration of twelve cytokines and growth factors (EGF, IL-1α, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IFN-γ, MCP-1, TNF-α and VEGF) by a multi-parametric biochip array in sputum and EBC of 24 CF patients before, after 6 and 15 days of therapy, and 15 days after the end of treatment for an acute exacerbation. Correlations with functional respiratory tests (FEV1, FVC) and the systemic marker C-reactive protein (CRP) were looked for. In sputum, before therapy, VEGF and IL-1β levels positively correlated with the respiratory function and CRP. Sputum IL-1α, IL-1β IL-4, IL-10, TNF-α, and VEGF significantly decreased, while EGF increased, during therapy. IL-8 and IL-4 levels negatively correlated with the respiratory function at 15 and 30 days from the start of therapy, respectively. IL-4, IL-6, IL-10 and TNF-α positively correlated with CRP during therapy. Although some EBC biomarkers correlated with respiratory function and CRP, no significant associations with these clinical parameters were found. Sputum IL-1β and VEGF might be considered biomarkers of an acute exacerbation in CF patients. A panel of sputum cytokines and growth factors may better describe the response to intravenous antibiotic treatment of CF than one single systemic marker.