Leukocyte differential and cell population data in the evaluation of SARS-CoV-2 and other infections

Background: Cell population data (CPD) are reported as part of leukocyte differentials by Mindray BC 6800Plus analyzer, give information of the size (Neu Z, Lym Z, Mon Z) nucleic acid content (Neu Y, Lym Y, Mon Y) and internal structure (Neu X, Lym X, Mon X) of leukocytes. We evaluated the potential utility of the leukocyte differential and CPD as laboratory indicators for the detection of coronavirus disease 2019 (COVID-19) in patients when admitted to the Emergency Department. Methods: A total of 672 patients with suspected infection were recruited at admission to the Hospital. The study group included 237 (151 COVID-19, 33 other virus, 53 bacterial infections). We applied the unsupervised K-means clustering method and principal component analysis (PCA). A validation group of 435 patients, 268 COVID-19 and 167 non-COVID-19 was used to verify the reliability of our model. Results: The COVID-19 cases presented the typical neutrophilia and lymphopenia, high Mon Z, and intermediate values of Neu X and Neu Y. The study group was classified into two clusters. This model was applied to the validation set;PCA analysis showed that almost 45.71% of the data variability could be explained by the two clusters. Cluster 1 had higher neutrophil counts, Neutrophil Lymphocyte ratio, Neu X, Neu Y and Mon Z, and Cluster 2, higher lymphocyte counts (P<0.05). Cluster 1 which included 91.4% of the COVID-19 patients and 60.5% of non-COVID-19 patients were assigned to Cluster 2, notably 100% of other viral infections. Conclusions: Leukocyte count (WBC) differential and CPD seem reliable parameters for the initial evaluation of patients with fever of unknown origin. By means of K analysis, the patients can be classified into distinct groups according to the etiology of the infection. © Journal of Laboratory and Precision Medicine. All rights reserved.