ABSTRACT
Background-aim: Coronavirus disease (COVID-19) caused by SARS-CoV-2 is characterized by high contagiousness requiring isolation measures. Currently, diagnosis is based on the RT-PCR and/or chest computed tomography (CT) scan, but these methodologies are time-consuming and may delay the diagnosis. CBC-Diff analysis is the first step in patient assessment and may contribute to the diagnosis of COVID-19. Morphological changes of the immune cells can be identified by electro-optical analysis on the hematology analyzer DxH 800 (Beckman Coulter, Inc., Brea, CA). We studied whether the analysis of cellular population data (CPD), provided as part of CBC-Diff analysis by the DxH 800 analyzers can help to identify SARS-CoV-2 infection. Methods: The study included 322 consecutive patients from the emergency unit with positive RT-PCR (Allplex 2019 nCoV Assay, Eurobio, Les Ulis, France) and 285 consecutive patients with clinical suspicion for COVID-19, but who had negative RT-PCR and CT-scan not suggestive of SARS-CoV-2 infection. We also included 137 subjects with a normal CBC-Diff, referred to our institution without evidence of infection and when prevalence of SARS-CoV-2 was very low in France. Blood was collected in EDTA-K3 tubes and analyzed within 6 h after collection. Results: The majority of CPD was different between the 3 groups;CPD of patients (with or without COVID-19) were significantly different of CPD of controls. Four, six and nine CPD for NE, LY, and MO, respectively, were significantly different between COVID-19+ and COVID-19- patients. Using ROC analysis, we identified parameters, which were able to discriminate COVID-19+ patients from COVID-19- patients. The best parameter was SD-V-Mo (Standard Deviation of Monocyte Volume), with AUC 0.819, sensitivity of 91.59% and specificity of 63.03% at the cut-off>21.71. MN-V-Mo (Mean Monocyte Volume) demonstrated AUC 0.742 with sensitivity of 76.64%, specificity of 65.85% at cut-off>180. SD-AL2-MO (Standard Deviation of Axial Light Loss for Monocytes) provided AUC 0.722 with sensitivity of 85.67%, specificity of 52.11% at cut-off>17.51. Currently CPD are research use only;their clinical utility has not been established. Conclusions: Consideration of CPD could constitute a first step and potentially aid in the early diagnosis of COVID-19.