Analysis of Changes in Variation of Neutrophil and Monocyte Parameters, Including Volume, Conductivity and Scatter in Sepsis Patients and Healthy Controls: A Cross-sectional Study

Abstract

Introduction: Sepsis continues to be a leading cause of mortality and prolonged hospitalisation. The conventional method of blood culture, while considered the gold standard, has limitations such as contamination and delayed reporting. The examination of peripheral smears has uncovered signs suggestive of septicaemia; however, these findings suffer from inter-observer variability and reliance on staining quality. Aim: To investigate the variation of neutrophil and monocyte parameters, including Volume, Conductivity, and Scatter (VCS), in sepsis compared to healthy controls. Materials and Methods: A cross-sectional analytical study was conducted at the Himalayan Institute of Medical Sciences, Swami Rama Himalayan University in Dehradun, Uttarakhand, over the course of one year, from January 2021 to December 2021, involving patients over 18 years of age categorised into sepsis group based on clinical suspicion, sepsis screen, blood culture, and Sequential Organ Failure Assessment (SOFA) score (n=117). A group of healthy controls was also included (n=140). Haematological investigations were performed using the DXH 800 Haematology Analyser (Beckman Coulter, CA, USA) with VCS Technology. Categorical variables were analysed using the Chi-square test, while non parametric data was compared using the Mann-Whitney U test. Results: The average age in the sepsis group was 50.17±13.17 years, while in the control group, it was 38.14±8.78 years. The results revealed higher White Blood Cell (WBC) counts (16.76±7.39)×103 / cumm in the sepsis group compared to healthy controls (6.68±1.42)×103 , absolute neutrophil counts (13.74±7.280)×103 in sepsis patients, and eosinopenia in the sepsis group (0.0114±0.0104)×103 compared to controls (0.23±0.116)×103 . Moreover, mean neutrophilic volumes (158.00±14.840) and monocytic volumes (182.58±18.64) were higher in the sepsis group, while they were lower in healthy controls, which were (149.52±5.23 and 171.17±6.28), respectively. Axial light loss for neutrophil and monocyte was 142.40±11.78 and 121.50±17.93, respectively, while it was lower in healthy controls showing a value of 135.51±7.63 and 119.45±8.25, respectively. Furthermore, mean neutrophilic and monocytic conductivity and scatter were decreased in sepsis. The observed higher WBC counts and absolute neutrophil counts in sepsis patients suggest a premature release of neutrophils from the bone marrow. The alterations in cell volume reflect an immune response. Additionally, the overall scatter of neutrophils and monocytes was reduced, accompanied by increased cellular transparency. Conclusion: The present study contributes valuable insights into the pathophysiological mechanisms underlying sepsis, emphasising the dynamic interplay between immune cells and their functional characteristics. Understanding these variations in cellular parameters could potentially aid in the development of more targeted diagnostic and therapeutic approaches for sepsis, ultimately improving patient outcomes. Further research is warranted to delve deeper into the specific mechanisms driving these observed changes and to explore their clinical implications in the context of sepsis management.