Neutrophil-to-lymphocyte ratio in chronic obstructive pulmonary disease: a retrospective study.

Chronic obstructive pulmonary disease (COPD) is a common chronic inflammatory disease of the lung with a high mortality and morbidity rate. Some of the inflammatory markers such as C-reactive protein (CRP), leukocyte count are associated with COPD. In this study, we aimed to evaluate the role of neutrophil-to-lymphocyte ratio (NLR) in COPD patients comparing with the other well-known inflammatory markers. We retrospectively enrolled the laboratory results of 269 COPD patients of which 178 patients at stable period and 91 patients during acute exacerbation and 50 sex- and age- matched healthy controls. We found that NLR values of the stable COPD patients were significantly higher than those of the controls (P < 0.001). During acute exacerbation of the disease there was a further increase compared to stable period (P < 0.001). NLR values were also positively correlated with serum CRP levels and red cell distribution width (RDW) and negatively correlated with mean platelet volume (MPV) in both COPD groups. In conclusion, NLR could be considered as a new inflammatory marker for assessment of inflammation in COPD patients with its quick, cheap, easily measurable property with routine complete blood count analysis.