Neutrophil-Lymphocyte Ratio as a Section Predictor of COPD Exacerbations: A Cross-sectional Study

Introduction: Chronic Obstructive Pulmonary Disease (COPD) is characterised by a modified inflammatory response to chronic irritants, which is often associated with some degree of systemic inflammation. Exacerbations in COPD are characterised by exaggeration of the ongoing inflammation. A number of inflammatory mediators are found to be raised in COPD exacerbations, but most of them are expensive and not readily available. The Neutrophil-lymphocyte Ratio (NLR) is a rapid, easy and cheap biomarker, that has been shown to be raised in patients of COPD.

Aim: To evaluate the role of NLR in patients of stable and acute exacerbation of COPD.

Materials and Methods: This cross-sectional observational study was conducted in Department of Pulmonary Medicine at Government Medical College, Patiala, Punjab, India. Study included 150 patients of stable COPD, 150 patients of Acute Exacerbation COPD (AECOPD) and 100 subjects as controls. NLR was calculated from a peripheral blood sample of the study participants. Continuous variables were summarised as mean with standard deviation and compared between groups using Unpaired t-test. A p-value <0.05 was considered statistically significant.

Results: The mean age in AECOPD group was 61.7±10.4 years, in stable COPD group was 63.1±8.9 years and 63.2±7.8 years in controls. Mean NLR was found to be highest in AECOPD group (4.0±1.7) followed by stable COPD (2.9±0.8) and then control (1.8±0.4). NLR showed good predictive value for predicting exacerbations in stable COPD patients with sensitivity and specificity of 75.3% and 70.7%, respectively (cut-off=3.4 and AUC=0.806).

Conclusion: The NLR is an easily available biomarker of inflammation and can be used as a predictor of exacerbation in patients of COPD.