An early warning indicator of mortality risk in patients with COVID-19: the neutrophil extracellular traps/neutrophilic segmented granulocyte ratio

Qiong Wang; Yu Qin; Jingyun Ma; Kehao Zhou; Guiping Xia; Ya Li; Li Xie; Richmond Godwin Afful; Qian Lan; Xingyu Huo; Jian Zou; Hailin Yang

doi:10.3389/fimmu.2024.1287132

An early warning indicator of mortality risk in patients with COVID-19: the neutrophil extracellular traps/neutrophilic segmented granulocyte ratio

Front Immunol. 2024 Jan 29:15:1287132. doi: 10.3389/fimmu.2024.1287132. eCollection 2024.

Authors

Qiong Wang¹, Yu Qin², Jingyun Ma¹, Kehao Zhou², Guiping Xia¹, Ya Li², Li Xie³, Richmond Godwin Afful², Qian Lan³, Xingyu Huo², Jian Zou¹, Hailin Yang²

Affiliations

¹ The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi People's Hospital, Wuxi Medical Center, Nanjing Medical University, Wuxi, China.
² Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China.
³ School of Internet of Things Engineering, Jiangnan University, Wuxi, China.

Abstract

Background: Neutrophil extracellular traps (NETs) play a key role in thrombus formation in patients with coronavirus disease 2019 (COVID-19). However, the existing detection and observation methods for NETs are limited in their ability to provide quantitative, convenient, and accurate descriptions of in situ NETs. Therefore, establishing a quantitative description of the relationship between NETs and thrombosis remains a challenge.

Objective: We employed morphological observations of blood cells and statistical analyses to investigate the correlation between the NETs/neutrophilic segmented granulocyte ratio and mortality risk in patients with COVID-19.

Methods: Peripheral blood samples were collected from 117 hospitalized patients with COVID-19 between November 2022 and February 2023, and various blood cell parameters were measured. Two types of smudge cells were observed in the blood and counted: lymphatic and neutral smudge cells. Statistical data analysis was used to establish COVID-19 mortality risk assessment indicators.

Results: Morphological observations of neutrophilic smudge cells revealed swelling, eruption, and NETs formation in the neutrophil nuclei. Subsequently, the NETs/neutrophilic segmented granulocyte ratio (NNSR) was calculated. A high concentration of NETs poses a fatal risk for thrombus formation in patients. Statistical analysis indicated that a high NNSR was more suitable for evaluating the risk of death in patients with COVID-19 compared to elevated fibrinogen (FIB) and D-dimer (DD) levels.

Conclusion: Observing blood cell morphology is an effective method for the detection of NETs, NNSR are important markers for revealing the mortality risk of patients with COVID-19.

Keywords: COVID-19; NETs/neutrophilic segmented granulocyte ratio; neutrophil extracellular traps (NETs); peripheral blood; smudge cells; thrombus.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

COVID-19* / metabolism
Extracellular Traps* / metabolism
Humans
Neutrophils / metabolism
Thrombosis* / metabolism

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This study was supported by grants from the National Key Research and Development Program of China (2022YFC3401300), the National Natural Science Foundation of China (No. 81904140, 21776113, 21878128).