Monocyte-related hematological indices in acute exacerbations of chronic obstructive pulmonary disease – a new biomarker?

C-reactive protein (CRP) and leukocyte count are standard tools for recognizing inflammation in chronic obstructive pulmonary disease (COPD) patients. This study aimed to find out whether there is a pattern in monocyte-related hematological indices [monocyte to neutrophil ratio (MNR) and monocyte to lymphocyte ratio (MLR)], which could help differentiate COPD patients in need of hospitalization due to acute exacerbation of COPD and distinguish frequent COPD exacerbators from non-frequent COPD exacerbators. The study included 119 COPD patients and 35 control subjects, recruited at the Clinic for Respiratory Diseases Jordanovac, University Hospital Centre Zagreb, Croatia. A complete blood count was performed on Sysmex XN-1000, CRP on Cobas c501, and fibrinogen on the BCS XP analyzer. Data were analyzed with MedCalc statistical software. The COPD patients were divided into three groups: frequent exacerbators (FE), non-frequent exacerbators (NFE), and patients hospitalized for acute COPD exacerbations (HAE), and the control group consisted of healthy smokers (HS). A statistically significant difference was found in the values of MNR while comparing these groups of patients: FE vs. HAE (p<0.000), NFE vs. HAE (p<0.000), and HS vs. HAE (p<0.001); and for the values of MLR: FE vs. HAE (p<0.022), NFE vs. HAE (p<0.000), and HS vs. HAE (p<0.000). As MLR and MNR have shown the statistical difference comparing the group of HAE to NFE, FE, and HS, MLR and MNR could be valuable and available markers of acute COPD exacerbations and the need for hospitalization.