Serum Angiopoietin-2 and C-reactive protein as biomarkers of acute exacerbations of chronic obstructive pulmonary diseases

ObjectivesTo evaluate the role of serum Angiopoietin-2 and C-reactive protein as blood biomarkers of acute exacerbation of COPD and to assess if they have a relationship with the severity of COPD and the severity grades of exacerbations.BackgroundRecently, Angiopoietin-2 (Ang-2) was identified as a ligand of the endothelial receptor tyrosine kinase, Tie-2. Ang-2 is an Angiopoietin-1 antagonist that plays a role in vascular destabilization and remodeling, which may increase in some diseases. However, serum Ang-2 levels have not been evaluated in patients with COPD.In this study, we examined serum Ang-2 concentrations in patients with COPD exacerbations and in patients with stable COPD.MethodsThis study was conducted on 36 COPD patients in acute exacerbation, 20 patients with stable COPD and 20 healthy subjects (control group), they were selected from the Shibin-Elkoom Chest Hospital from February 2013 to October 2013. All subjects were subjected to detailed clinical history, thorough clinical examination, Modified British Medical Research Council (mMRC) questionnaire and the COPD Assessment Test questionnaire (CAT) to assess symptoms, plain chest-X-ray (postero-anterior and lateral views). Blood sample for the measurement of Angiopoietin-2 and C-reactive protein by ELISA.ResultsSerum concentrations of Ang-2 and CRP were significantly higher in patients with acute exacerbations of COPD than in those with stable COPD or control subjects. Ang-2 was significantly positively correlated with serum CRP levels but negatively correlated with PaO2 in patients with exacerbations.ConclusionSerum levels of Ang-2 and CRP are significantly elevated during acute exacerbations of COPD, as compared with stable COPD.