Time-dependent changes in cell population data obtained using Sysmex XN-series hematology analyzer in bacterial infections.

BACKGROUND: Time-dependent changes in cell populations during acute bacterial infections remain unclear. We assessed time-dependent changes in fluorescent light intensity of the neutrophil area (NE-SFL) and fluorescent light distribution width index of the neutrophil area (NE-WY) and their association with sepsis and bacteremia. METHODS: Patients with acute bacterial infections were enrolled in this prospective, observational cohort study. Blood samples were collected from all patients at the onset of bacterial infections (day 0) and on days 1 and 3. Microbiological evaluation included the examination of blood bacterial load using PCR. Cell population data were assessed using an automated hematology analyzer (Sysmex series XN-2000). RESULTS: Forty-three participants with acute bacterial infections were enrolled in the study. Twenty-five participants developed definite sepsis. All the participants improved after the onset of infection. NE-WY levels showed significant time-dependent changes in participants with sepsis, peaking on day 0 and significantly decreasing until day 3, whereas these changes were not statistically significant for NE-SFL. A significant correlation with the Sequential Organ Failure Assessment score was observed with NE-WY and NE-SFL in the entire cohort on days 0 and 1. However, only NE-WY showed a significant correlation with blood bacterial load on days 0 and 1. CONCLUSION: This study demonstrated that NE-WY elevation in sepsis peaked earlier than NE-SFL, which may partly reflect the early bacterial invasion into circulation. These findings advocate caution in interpreting cell population data values as sepsis biomarkers and propose the potential of NE-WY as a therapeutic indicator.

Robustness assessment of an automated AI-based white blood cell morphometric analysis system using different smear preparation methods.

INTRODUCTION: Numerous AI-based systems are being developed to evaluate peripheral blood (PB) smears, but the feasibility of these systems on different smear preparation methods has not been fully understood. In this study, we assessed the impact of different smear preparation methods on the robustness of the deep learning system (DLS). METHODS: We collected 193 PB samples from patients, preparing a pair of smears for each sample using two systems: (1) SP50 smears, prepared by the DLS recommended fully automated slide preparation with double fan drying and staining (May-Grunwald Giemsa, M-G) system using SP50 (Sysmex) and (2) SP1000i smears, prepared by automated smear preparation with single fan drying by SP1000i (Sysmex) and manually stained with M-G. Digital images of PB cells were captured using DI-60 (Sysmex), and the DLS performed cell classification. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were used to evaluate the performance of the DLS. RESULTS: The specificity and NPV for all cell types were 97.4%-100% in both smear sets. The average sensitivity and PPV were 88.9% and 90.1% on SP50 smears, and 87.0% and 83.2% on SP1000i smears, respectively. The lower performance on SP1000i smears was attributed to the intra-lineage misclassification of neutrophil precursors and inter-lineage misclassification of lymphocytes. CONCLUSION: The DLS demonstrated consistent performance in specificity and NPV for smears prepared by a system different from the recommended method. Our results suggest that applying an automated smear preparation system optimized for the DLS system may be important.

Defining a metrologically traceable and sustainable calibration hierarchy of international normalized ratio for monitoring of vitamin K antagonist treatment in accordance with International Organization for Standardization (ISO) 17511:2020 standard: communication from the International Federation of Clinical Chemistry and Laboratory Medicine-SSC/ISTH working group on prothrombin time/international normalized ratio standardization.

Calibration of prothrombin time (PT) in terms of international normalized ratio (INR) has been outlined in "Guidelines for thromboplastins and plasmas used to control oral anticoagulant therapy" (World Health Organization, 2013). The international standard ISO 17511:2020 presents requirements for manufacturers of in vitro diagnostic (IVD) medical devices (MDs) for documenting the calibration hierarchy for a measured quantity in human samples using a specified IVD MD. The objective of this article is to define an unequivocal, metrologically traceable calibration hierarchy for the INR measured in plasma as well as in whole blood samples. Calibration of PT and INR for IVD MDs according to World Health Organization guidelines is similar to that in cases where there is a reference measurement procedure that defines the measurand for value assignment as described in ISO 17511:2020. We conclude that, for PT/INR standardization, the optimal calibration hierarchy includes a primary process to prepare an international reference reagent and measurement procedure that defines the measurand by a value assignment protocol conforming to clause 5.3 of ISO 17511:2020. A panel of freshly prepared human plasma samples from healthy adult individuals and patients on vitamin K antagonists is used as a commutable secondary calibrator as described in ISO 17511:2020. A sustainable metrologically traceable calibration hierarchy for INR should be based on an international protocol for value assignment with a single primary reference thromboplastin and the harmonized manual tilt tube technique for clotting time determination. The primary international reference thromboplastin reagent should be used only for calibration of successive batches of the secondary reference thromboplastin reagent.

Predictive value of cell population data with Sysmex XN-series hematology analyzer for culture-proven bacteremia.

Background: Cell 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. Methods: Patients 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. Results: Of 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 < 0.005, respectively), and were significantly correlated with the bacterial load determined by PCR (r = 0.384 and r = 0.374, p < 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. Conclusion: This 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.

Peripheral granular lymphocytopenia and dysmorphic leukocytosis as simple prognostic markers in COVID-19.

INTRODUCTION: Developing prognostic markers can be useful for clinical decision-making. 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 (COVID-19). 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.