The Biomarker Potential of the Neutrophil-to-Lymphocyte Ratio in Acute Exacerbation of Chronic Obstructive Pulmonary Disease.

Background Chronic obstructive pulmonary disease (COPD) is characterized by periods of exacerbations and seasonal variations due to the recruitment of inflammatory cells. Various cells, such as neutrophils, lymphocytes, and the inflammatory mediators released by them, play a role in its pathogenesis. The current study was conducted to determine the role of the neutrophil-to-lymphocyte ratio (NLR) as a marker in acute exacerbation of COPD (AECOPD). Materials and methods We conducted a cross-sectional observational study at a tertiary care center in Western Maharashtra over six months after receiving approval from the institutional ethics committee. The study included 50 patients with AECOPD and 30 age and gender-matched controls without COPD. The patients were examined with a detailed history, complete blood count, and spirometry. The NLR was calculated and patients' disease severity was assessed using Global Initiative for Chronic Obstructive Lung Disease (GOLD) staging. Results The mean age in the AECOPD group was 67.5 ± 12.5 years, whereas it was 46.2 ± 18.5 years in the control group. There was a male predominance in the AECOPD group (32/50). The majority of patients were in the GOLD stage 2 (42/50), followed by GOLD stage 3 (7/50). A total of 28 out of 50 AECOPD patients required admission to the medical intensive care unit. In the AECOPD group, 39 were smokers, and 11 were nonsmokers. Smoking was significantly associated with AECOPD when compared with controls. The mean NLR was 10.9 ± 10.2 in AECOPD patients and 4.3 ± 3.1 in the controls. Among cases with high NLR (≥5), seven required mechanical ventilation, 13 required noninvasive ventilation (NIV), and six succumbed to death. The mean duration of mechanical ventilation in this group was 12.5 ± 4.5 days, and for NIV, it was 7.5 ± 5.5 days. Conversely, patients with lower NLR (≤5) were more likely to avoid artificial ventilation and had a better in-hospital outcome. Conclusion COPD exacerbations can harm a patient's health, lead to disease progression, and increase mortality rates. Predicting exacerbations in advance can aid in early detection and treatment. NLR is an inexpensive, noninvasive, and easily available marker of inflammation and a predictor of outcome in AECOPD patients and hence should be calculated routinely in all patients with COPD.