Association between admission neutrophil to lymphocyte ratio and outcomes in patients with acute exacerbation of chronic obstructive pulmonary disease

The prognostic significance of neutrophil-to-lymphocyte ratio (NLR), derived-neutrophil-to-lymphocyte ratio (d-NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR) have been shown in many diseases. To the best of our knowledge, there is no published report evaluation of those parameters in acute exacerbation of chronic obstructive pulmonary disease (AECOPD). The aims of this study are to evaluate the parameters in predicting in-hospital mortality in patients with AECOPD. This is a retrospective study in two referral hospitals in Tabriz and Urmia, Iran. NLRs, PLR, LMR, and d-NLR were calculated from the admission day complete blood count of patients with AECOPD. Comparison was made between patients who died in hospital and those discharged alive. Of 315 patients, 70 (22.2%) died in the hospital and 245 (77.8%) were discharged alive. The mortality rate was higher in patients with NLR ≥ 4 than with NLR < 4 (24% vs. 9.5% p value < 0.001). Multivariate analysis revealed NLR (p= 0.001) were independently associated with in-hospital mortality. NLR had the highest odds ratio for death both in univariate (OR= 3.80) and multivariate (OR= 3.50) analyses. The area under the receiver-operating characteristic curve for NLR in predicting in-hospital death was 0.72 (95% CI: 0.62-0.81; p< 0.001). PLR and LMR did not show significant relation to in-hospital death in AECOPD. This study shows for the first time that higher NLR is positively associated with in-hospital mortality in AECOPD.