The neutrophil-to-lymphocyte ratio as a marker of chronic obstructive pulmonary disease and its exacerbations: A systematic review and meta-analysis.

Our meta-analysis showed that NLR values are significantly higher in stable COPD patients when compared to healthy individuals, although the magnitude of the difference is reduced after trim and fill adjustment, and in patients with COPD exacerbations when compared to patients with stable disease. Further studies, in larger cohorts, are needed to confirm whether the NLR is a useful tool in discriminating between COPD patients with stable disease, those with acute exacerbations, and subjects without the disease.