Association Between Neutrophil and Platelet to Lymphocyte Ratio and Disease Severity in Stable COPD

Abstract

Background: Chronic obstructive pulmonary disease (COPD) is characterized by the presence of air flow limitation and exacerbations caused by inflammation. Recently, blood neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) have been shown to be valuable predictors of inflammatory conditions and are used for risk stratification of different diseases. During COPD exacerbation, NLR and PLR are associated to mortality, ICU occupancy and need for NIV. Methods: We therefore conducted a retrospective study in stable COPD patients to evaluate the role of NLR in phenotyping COPD patients. The study included COPD patients ≥ 40 years, current or former smokers (pack/years ≥10) with documented FEV1/FVC Results: From 66 consecutive COPD patients, 46 met the inclusion criteria. 8 (17.4%) patients were group A, 21 (45.6%) group B, 2 (4.3%) group C, 15 (32.6%) group D. Mean NLR was 2.86±1.76; Mean PLR was 136.9±77.0. The cut-off value of NLR was arbitrarily defined based on the upper quartile point as 3.3. Patients with high NLR showed lower FEV1 (p= 0.036), FVC (p=0.048), with more symptoms (p=0.029) and worse COPD stage (p=0.01). Interestingly, patients with high NLR were more likely under ICS treatment (p=0.059). A PLR ratio cut-off of 158.0 discriminated patients more symptomatic (p=0.01) and with worse disease stage (p=0.01). Conclusions: NLR and PLR are independently associated with disease severity in stable COPD.