Analysis of the use of blood parameters in COPD and ACOS for the purposes of disease differentiation

. The definition of asthma‑chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS) has recently been changed to ‘ACO’ in cases in which certain clinical manifestations of both asthma and COPD are present. In ACO, difficulties in diagnosis and differential diagnosis occur, since inflammation and related pathophysiological changes cannot be clearly demonstrated. In the present study, blood parameters were evaluated with regards to the differ‑ ential diagnosis of ACO‑COPD and are presented with the aim of providing an approach that is easy to apply in daily practice. The present study was conducted in February, 2020 on patients who presented to the pulmonology department. A total of 50 patients with COPD and 51 patients with ACO who were newly diagnosed were included in the study. The results revealed that there were significant differences between the ACO and COPD groups in terms of their neutrophil and lymphocyte counts, platelet (PLT) and C‑reactive protein (CRP) counts, neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) (P<0.05). However, no statistically significant differences were found between the groups in terms of their eosinophil ratio and mean platelet volume (MPV) count (P>0.05). The mean neutrophil count, NLR, PLR and CRP values were significantly higher in the COPD group than the ACO group. In the ACO group, the mean PLT and lymphocyte count values were significantly higher than those in the COPD group. According to the findings of the present study, although role of inflammation in ACO has not been fully clarified, the presence of eosinophilia in ACO does not significantly contribute to the differential diagnosis of COPD. MPV also lacks clinically significant differential properties in COPD and ACO. However, the mean PLT and lymphocyte counts were significantly higher in the ACO than in the COPD group, which maybe a promising result in the differential diagnosis of COPD. Thus, the present study may provide insight into the differential diagnosis between 55.2% among patients with COPD and between 13.3 and 61.0% among patients with asthma alone (7). In another, multicenter, cross‑sectional, observational study, the number of patients