International Journal of COPD (Nov 2018)
Defining the role of neutrophil-to-lymphocyte ratio in COPD: a systematic literature review
Abstract
Yuliana Pascual-González,1 Marta López-Sánchez,1 Jordi Dorca,1 Salud Santos1,2 1Department of Respiratory Medicine, Bellvitge University Hospital – IDIBELL, University of Barcelona, L’Hospitalet de Llobregat, Barcelona, Spain; 2Biomedical Research Networking Center Consortium – Respiratory Diseases (CIBERES), Barcelona, Spain Abstract: COPD is characterized by a pulmonary and systemic inflammatory process. Several authors have reported the elevation of multiple inflammatory markers in patients with COPD; however, their use in routine clinical practice has limitations. The neutrophil-to-lymphocyte ratio (NLR) is a useful and cost-effective inflammatory marker derived from routine complete blood count. We performed a systematic literature review using the PRISMA statement. Twenty-two articles were included, recruiting 7,601 COPD patients and 784 healthy controls. Compared with controls, COPD patients had significantly higher NLR values. We found a significant correlation between the NLR and clinical/functional parameters (FEV1, mMRC, and BODE index) in COPD patients. Elevation of the NLR is associated with the diagnosis of acute exacerbation of COPD (pooled data propose a cut-off value of 3.34 with a median sensitivity, specificity, and area under the curve of 80%, 86%, and 0.86, respectively). Additionally, increased NLR is also associated with the diagnosis of a bacterial infection in exacerbated patients, with a cut-off value of 7.30, although with a low sensitivity and specificity. The NLR is an independent predictor of in-hospital and late mortality after exacerbation. In conclusion, the NLR could be a useful marker in COPD patients; however, further studies are needed to better identify the clinical value of the NLR. Keywords: acute exacerbations of COPD, bacterial infection, mortality in COPD, inflammatory biomarkers, eosinophilia, GOLD stage
