A Study on Neutrophil Lymphocyte Ratio and C - reactive protein Levels in Acute Exacerbation of Chronic Obstructive Pulmonary Disease and Its Correlation with Clinical Outcome

Abstract

Background: Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is a major cause of hospitalization and mortality among patients with COPD. Identifying simple and readily available biomarkers that predict disease severity and clinical outcomes is essential for improving patient management. This study evaluated the roles of the neutrophil-to-lymphocyte ratio (NLR) and C-reactive protein (CRP) in patients admitted with AECOPD and assessed their associations with clinical outcomes.

Methods: A hospital-based prospective observational study was conducted among 60 patients aged 40–70 years admitted with AECOPD to the Department of General Medicine and MICU at PESIMSR Hospital, Kuppam, between April 2024 and October 2025. Demographic, clinical, and laboratory data including complete blood count and CRP levels were collected. NLR was calculated from differential leukocyte counts. Associations of NLR and CRP with disease severity, ICU admission, ventilator requirement, duration of hospital stay, and mortality were analyzed.

Results: The mean NLR and CRP levels were 5.44 ± 1.37 and 40.5 ± 15.5 mg/L, respectively. Neither NLR nor CRP showed a significant association with AECOPD severity, ICU admission, or duration of hospital stay. Elevated CRP levels were significantly associated with ventilator requirement (p < 0.001). NLR was significantly higher among non-survivors compared with survivors (6.11 ± 3.38 vs. 5.42 ± 1.32; p = 0.016). High NLR was also significantly associated with ventilator support, ICU admission, and prolonged hospitalization.

Conclusion: NLR appears to be a simple, inexpensive, and useful prognostic marker for adverse outcomes in AECOPD, while CRP may help identify patients at risk of requiring ventilatory support.