The Importance of Neutrophil to Lymphocyte Ratio and Peripheral Blood Eosinophilia in Chronic Obstructive Pulmonary Disease Patients with Acute Exacerbation: Recent Studies

Chronic obstructive pulmonary disease (COPD) is a chronic, progressive respiratory disease and the third leading cause of respiratory disease mortality. The diagnosis of COPD is changed to acute exacerbation of COPD (AECOPD) when respiratory symptoms become worse, beyond normal day-to-day variations and severely enough that changes in medication are required. Both neutrophils to lymphocyte ratio (NLR) and peripheral blood eosinophilia (PBE) are rapid and relatively inexpensive tests that can be easily applied in the clinical practice for the diagnosis and treatment of AECOPD patients. Furthermore, current studies found that NLR and PBE had a higher accuracy rate than other traditional markers (Leukocyte count and C-reactive protein) for the diagnosis and management of AECOPD. Besides, recent studies determined that NLR and PBE can be used for prediction of future exacerbations in COPD patients. This review aims to explore the current knowledge about the significance of NLR and PBE in AECOPD patients.