Introduction: Developing prognostic markers can be useful for clinical decisionmaking. Peripheral blood (PB) examination is simple and basic that can be performed in any facility. We aimed to investigate whether PB examination can predict prognosis in coronavirus disease . Methods: Complete blood count (CBC) and PB cell morphology were examined in 38 healthy controls (HCs) and 40 patients with COVID-19. Patients with COVID-19, including 26 mild and 14 severe cases, were hospitalized in Juntendo University Hospital (Tokyo, Japan) between April 1 and August 6, 2020. PB examinations were performed using Sysmex XN-3000 automated hematology analyzer and Sysmex DI-60 employing the convolutional neural network-based automatic image-recognition system.Results: Compared with mild cases, severe cases showed a significantly higher incidence of anemia, lymphopenia, and leukocytosis (P < .001). Granular lymphocyte counts were normal or higher in mild cases and persistently decreased in fatal cases.Temporary increase in granular lymphocytes was associated with survival of patients with severe infection. Red cell distribution width was significantly higher in severe cases than in mild cases (P < .001). Neutrophil dysplasia was consistently observed in COVID-19 cases, but not in HCs. Levels of giant neutrophils and toxic granulation/ Döhle bodies were increased in severe cases. Conclusion:Basic PB examination can be useful to predict the prognosis of COVID-19, by detecting SARS-CoV-2 infection-induced multi-lineage changes in blood cell counts and morphological anomalies. These changes were dynamically correlated with disease severity and may be associated with disruption of hematopoiesis and the immunological system due to bone marrow stress in severe infection.

BackgroundCell population data (CPD) parameters related to neutrophils, such as fluorescent light intensity (NE-SFL) and fluorescent light distribution width index (NE-WY), have emerged as potential biomarkers for sepsis. However, the diagnostic implication in acute bacterial infection remains unclear. This study assessed the diagnostic value of NE-WY and NE-SFL for bacteremia in patients with acute bacterial infections, and those associations with other sepsis biomarkers.MethodsPatients with acute bacterial infections were enrolled in this prospective observational cohort study. For all patients, a blood sample, with at least two sets of blood cultures, were collected at the onset of infection. Microbiological evaluation included examination of the blood bacterial load using PCR. CPD was assessed using Automated Hematology analyzer Sysmex series XN-2000. Serum levels of procalcitonin (PCT), interleukin-6 (IL-6), presepsin, and CRP were also assessed.ResultsOf 93 patients with acute bacterial infection, 24 developed culture-proven bacteremia and 69 did not. NE-SFL and NE-WY were significantly higher in patients with bacteremia than in those without bacteremia (p &lt; 0.005, respectively), and were significantly correlated with the bacterial load determined by PCR (r = 0.384 and r = 0.374, p &lt; 0.005, respectively). To assess the diagnostic value for bacteremia, receiver operating characteristic curve analysis was used. NE-SFL and NE-WY showed an area under the curve of 0.685 and 0.708, respectively, while those of PCT, IL-6, presepsin, and CRP were 0.744, 0.778, 0.685, and 0.528, respectively. Correlation analysis showed that the levels of NE-WY and NE-SFL were strongly correlated with PCT and IL-6 levels.ConclusionThis study demonstrated that NE-WY and NE-SFL could predict bacteremia in a manner that may be different from that of other indicators. These findings suggest there are potential benefits of NE-WY/NE-SFL in predicting severe bacterial infections.

Since late 2019, the COVID-19 pandemic, caused by SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2), has had an enormous impact on the medical field and society across the world. 1 To