Describing Characteristics and Differences of Neutrophils in Sepsis, Trauma, and Control Patients in Routinely Measured Hematology Data.

Huibert-Jan Joosse,Wouter Van Van Solinge,Falco Hietbrink,Saskia Haitjema,Imo Hoefer,Albert Huisman

doi:10.3390/biomedicines10030633

Huibert-Jan Joosse, Wouter Van Van Solinge + Show 4 more

Open Access

https://doi.org/10.3390/biomedicines10030633

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Journal: Biomedicines	Publication Date: Mar 9, 2022
Citations: 1	License type: CC BY 4.0

Affiliation: University Medical Center Utrecht

Abstract

Neutrophils have an important role in the immune response. These cells can be subjected to an impaired function and a shift in population depending on disease states. In sepsis, this shift is recognized and flagged by automated hematology analyzers, including the presence of band neutrophils, while these cells, although present, appear not to be detected in trauma patients. To better understand this suspected error in flagging, we set out to distinguish neutrophil populations of these two patient groups and compared these with controls. Different data-driven methods were used compared to standard algorithms used by the software of the analyzers. Using K-means clustering, we extracted neutrophils from raw hematology analyzer datafiles, and compared characteristics of these clusters between the patient groups. We observed an increased neutrophil size for both sepsis and trauma patients, but trauma patients had a smaller increase. Trauma patients also had a high proportion of cells with relatively high nuclear segmentation, which is contradictory with the presence of band neutrophils. This, in combination with the smaller size increase, might explain the inability to flag band neutrophils in trauma.

Highlights

Neutrophils are among the body’s first cellular responders to infections and tissue damage
Data from 20 samples were selected for this study, of which 7 samples were from sepsis patients, 4 samples were from trauma patients, and 9 samples were of control patients
Depolarized Side Scatter (DSS)/Polarized Side Scatter (PSS) and FL3 values, cluster 4 is described by low FL3 and DSS/PSS values, and cluster 5 is described by relatively high FL3 values and low DSS/PSS values. In this data-driven hypothesis-generating study, we investigated why automated hematology analyzers are unable to identify neutrophil bands in patients with trauma, using data on leukocytes from three patient groups: sepsis, trauma, and controls

Summary

Introduction

Neutrophils are among the body’s first cellular responders to infections and tissue damage. Their functionality and capability to limit pathogen invasion and remove pathogens (e.g., by phagocytosis) is essential in host defense. Impaired neutrophil function leads to an impaired immune response and can result in exacerbation of infections towards sepsis [1]. The ability of neutrophils to take up pathogens by phagocytosis and their elimination are crucial in this context and depend on their level of maturity and composition, albeit that these two abilities are not necessarily directly linked [2,3]. After (severe) trauma, patients are known to be at increased risk for complications because of the activation of neutrophils after tissue damage through damage-associated molecular patterns (DAMPs) and microbe-associated molecular patterns (MAMPs) [4,5].

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