Neutrophil/lymphocyte (NLR) ratio in infectious acute exacerbations of COPD (AECOPD)

Neutrophil/lymphocyte (NLR) ratio has been used as a marker of systemic inflammation in several inflammatory conditions. As infection is the main cause leading to acute exacerbations of COPD (AECOPD), aim of this study was to investigate whether NLR could be used as a marker of AECOPD, and if it is correlated with other well established markers of inflammation, such as C-reactive protein (CRP) and procalsitonin (PCT). We examined 40 patients with COPD hospitalized for an infectious AECOPD according to Anthonisen9s criteria. Blood was taken on admission and after the treatment of AECOPD. NLR, CRP, and PCT were measured and compared between exacerbation state and after treatment. Mean levels of NLR were 5.38±4.6 (mean±SD) on admission and 2.1±0.67 (p=0.003) after treatment. A cut-off value for NLR on admission of 2.7 (sensitivity 78.3%, specificity 85.7%) could predict the AECOPD, with receiver-operating characteristic (ROC) curve showing an area under curve (AUC) 0.87, p=0.004. NLR showed a good correlation with CRP and PCT only on admission for AECOPD (r=0.576, p=0.01, and r=0.635, p=0.036, respectively). NLR showed a highly prognostic accuracy for infectious AECOPD. Since NLR is a widely available and cost-effective measurement it could be of value in clinical practice.