Volume Conductivity and Scatter Parameters as an Indicator of Acute Bacterial Infections by the Automated Haematology Analyser

Utility of VCS Parameters as a Cost-effective and Early Marker of Sepsis: A Hospital-based Study

Introduction

Sepsis is a life-threatening condition. Nowadays, hospitals rely on laboratory parameters like CRP and procalcitonin to detect sepsis. There is a need to evaluate and validate more accurate and early predictors of sepsis in critically ill patients. We analyzed volume, conductivity, and scatter (VCS) parameters of leukocytes in sepsis patients and compared them with the control group with no illness.

Materials and methods

It was a prospective case-control study. A total of 80 patients were studied with 40 sepsis cases and 40 controls. Peripheral smear examination was done in all the cases. Other parameters, such as WBC count, neutrophil%, absolute neutrophil count (ANC), High-sensitive C-reactive protein (hs-CRP), procalcitonin, and blood cultures were analyzed. We took the data of the patients from medical records and correlated it with other tests. Complete blood picture reports were generated by the Beckman Coulter LH series (LH 750 and 780). VCS parameters for neutrophils, lymphocytes and monocytes were compared between both groups. The results were analyzed using SPSS software (16.0 version).

Results

The age group was 20-85 years with male predominance. The mean neutrophil volume (MNV) and mean monocyte volume (MMV) were higher in the sepsis group when compared with the control group. The mean neutrophil conductivity and scatter was lower in the sepsis group and comparatively higher in the control group, but it was insignificant. The mean neutrophil volume values were higher in the sepsis group even with low total leukocyte count (TLC) when the patient had sepsis. There is no change in the mean lymphocyte VCS parameter and mean monocyte conductivity, scatter in both the groups.

Conclusion

The mean neutrophil volume and MMV are found to be good sensitive markers in the prediction of sepsis. Even when TLC is on the lower side in patients with sepsis, these parameters predict sepsis accurately. This helps clinicians to assess sepsis in patients at an early stage and has an important practical implication.

How to cite this article

Goyal H, Singhal A, Joseph M. Utility of VCS Parameters as a Cost-effective and Early Marker of Sepsis: A Hospital-based Study. Indian J Crit Care Med 2023;27(9):647-650.

Role of Automated Volume, Conductivity and Scatter (VCS) Parameters of Neutrophils as Indicators of Sepsis

This study was done to evaluate the role of automated volume, conductivity and scatter (VCS) parameters of neutrophils as indicators of sepsis and its differentiation from other inflammatory disorders. In this cross-sectional study, 225 patients with culture proven or with clinical evidence of sepsis were included along with an equal number of healthy controls. In addition, 138 patients with non-infective inflammatory conditions-acute pancreatitis (50), burns (45) and acute myocardial infarction (43) were also included. Complete blood count was done on LH750 automated hematology analyser (Beckman Coulter). VCS data; mean neutrophil volume (MNV), mean neutrophil conductivity (MNC) and mean neutrophil scatter (MNS) for all patients was recorded. MNV was high (p < .0001) while MNS was lower (p < .0001) in patients with sepsis compared to the control group. MNC was comparable between the two groups (p = .4735). On subgroup analysis of patients with sepsis, significant difference in MNV (p = .0009) and MNS (p = .0210) was observed in patients with leukopenia, normal TLC and leucocytosis. Youden Index was maximum (71%) at MNV of 144.6 (sensitivity-82.7%; specificity-88.5%) and MNV of 147.9 (sensitivity-75.6%; specificity-95.6%) for sepsis. On comparing patients with sepsis with acute pancreatitis and myocardial infarction, MNV and MNC were significantly higher in patients with sepsis. MNV is a useful, inexpensive parameter which can be accessed during a routine CBC run from the raw data. It can be utilized as an early indicator of sepsis as an adjunct to the clinical diagnosis in suspect patients. However, its availability in only select hematology analyzers may limit its use.

Discriminant value of automated leucocyte VCS parameters in the detection of tropical infections

Introduction

In India, infectious diseases are a leading treatable cause of morbidity and mortality. Mangalore being endemic to many vector‐borne diseases, their incidence is known to show seasonal variations with sharp increase during monsoon. Leucocytes have substantial role in the immunological pathogenesis of infections.

Methods

The present series was a hospital‐based cross‐sectional study performed in a tertiary care hospital for a period of three months from June‐August wherein the cell population data of cases of malaria, dengue, leptospirosis, typhoid and rickettsial infections along with equal number of healthy controls were collected and analysed. Effectiveness of leucocyte‐related volume (V), conductivity (C) and scatter (S) parameters by Coulter®DXH800 haematology analyser in predicting these infections was appraised.

Results

A total of 324 cases comprising of malaria (50%), dengue (30.9%), leptospirosis (13.9%), typhoid (4.0%) and rickettsial infections (1.2%) were included. There was statistically significant differences (P < 0.05) in the mean values of complete blood count parameters—haemoglobin, total leucocyte count, red blood cell count, haematocrit, red cell distribution width, differential leucocyte count, platelet count and plateletcrit between cases and controls and also between specific infections. The mean volumes of neutrophil, monocyte and lymphocyte were considerably increased in malaria and dengue fever compared to leptospirosis, typhoid and rickettsial infections. VCS parameters were the least altered in typhoid fever, except for a strikingly high conductivity and scatter of eosinophils.

Conclusions

Haematological analysis is a part of routine evaluation of any case of febrile illness. This study showed that there are specific alterations in VCS parameters in different types of infections such as malaria, dengue, leptospira, typhoid and rickettsia, the information and analysis of which comes without any additional cost.

Volume, conductivity, and scatter parameters of leukocytes as early markers of sepsis and treatment response

INTRODUCTION:

Morphologic changes in the size and granularity of leukocytes seen in sepsis could be measured using the volume, conductivity, and scatter (VCS parameters) from the automated hematology analyzers. The objective of this study is to find the clinical usefulness of VCS parameters as possible indicators of sepsis and to determine the effect of treatment on these parameters.

METHODS:

This observational study was conducted in a tertiary level hospital in India. Hemogram and VCS parameters obtained from LH 750 (Beckman coulter, Fullerton, CA) from 134 proven blood culture-positive cases of sepsis were reviewed on the day of culture positivity (day 0), day 3, and day 7 were analyzed and compared with those of samples from otherwise healthy 100 participants. Statistical analysis of data was done, and cutoff value was established using receiver-operator characteristic curve.

RESULTS:

Out of 134 culture-positive cases, 55.2% (n = 74) Gram-negative and 44.8% (n = 60) Gram-positive bacteria were isolated. The mean neutrophil volume (MNV) and mean monocyte volume (MMV) were higher in the sepsis group compared to that of the control group (165.43 ± 18.21 vs. 140.59 ± 7.6, P = 0.001 for MNV and 179.8 ± 14.16 vs. 164.54 ± 9.6, P = 0.001 for MMV). A significant decrease in MNV and MMV was observed with the initiation of the treatment. Significant changes in scatter and conductivity parameters were also noticed. A cutoff value of 150.2 for MNV gave a sensitivity and specificity of 79.1% and 95%, respectively, with an area under the curve (AUC) of 92.3%. With a cutoff of 168.3, MMV had a sensitivity of 80.6% and specificity of 77.5%, AUC of 83%.

CONCLUSION:

VCS parameters such as MNV and MMV can be easily obtained by an automated hematology analyzer and could be used for early detection and therapeutic response in sepsis.

Effects of Smoking on Volume, Conductivity and Scatter Parameters of Leukocytes

Aim: In this study, we aimed to determine changes in leukocytes volume, conductivity and scatter parameters in smokers compared to non-smokers. Methods: A total of 117 individuals (45 smokers and 72 non-smokers) were included in the study. While those who smoked at least 10 pack-years were included in the case group, those who never smoked at all were included in the control group. Results: While there was a statistically significant difference in mean neutrophil volume, mean neutrophil conductivity, mean lymphocyte conductivity, mean lymphocyte scatter, mean monocyte volume, mean monocyte conductivity, mean monocyte scatter, mean eosinophil conductivity values between the two groups, there was no statistically significant difference in mean neutrophil scatter, mean lymphocyte volume, mean eosinophil volume, mean eosinophil scatter values between the two groups. Conclusion: This study showed that smoking affected volume, conductivity and scatter parameters. Clinicians should consider whether the patient smokes if they want to diagnose any diseases using volume, conductivity and scatter parameters. Keywords: smoking, leukocytes, conductivity, scattering, neutrophils

MEG3 Alleviated LPS-Induced Intestinal Injury in Sepsis by Modulating miR-129-5p and Surfactant Protein D

Sepsis and intestinal injury triggered by sepsis are common in intensive care units, which can contribute to a high mortality. lncRNAs can modulate gene expression, and they are closely involved in multiple diseases, including sepsis. In our present study, we investigated the biological function of MEG3 in sepsis, especially during the intestinal injury. Currently, we observed that in LPS-induced sepsis mouse models, the intestinal injury was triggered. Meanwhile, we reported that MEG3 was greatly decreased in vivo, with an increase of miR-129-5p and inhibition of SP-D. Then, MEG3 was overexpressed, and we found that its overexpression repressed the intestinal injury via downregulating miR-129-5p in sepsis mice. Moreover, TNF-α and IL-6 expression was elevated in intestinal tissues compared to the control groups. MEG3 restrained the activation of TNF-α and IL-6, in sepsis models. Subsequently, to induce the inflammatory injury of sepsis, human colorectal Caco2 cells were treated with 10 ng/ml LPS. 10 ng/ml LPS significantly inhibited Caco2 cell proliferation and increased the apoptosis. Additionally, MEG3 was decreased whereas miR-129-5p was obviously increased in Caco2 cells incubated with LPS. Interestingly, we showed that MEG3 repressed cell apoptosis partly and enhanced Caco2 cell proliferation. miR-129-5p overexpression could reverse the effect of MEG3 in vitro. Previously, we proved SP-D was reduced in sepsis and it depressed the intestinal injury in vivo. Finally, the correlation among MEG3, miR-129-5p, and SP-D was predicted and confirmed in our investigation. These findings indicated that MEG3 might be a potential target for intestinal damage caused by sepsis via regulating miR-129-5p and SP-D.

Expression of microRNA-23b in patients with sepsis and its effect on leukocytes and the expression of E-selectin and ICAM-1

The expression of microRNA-23b in peripheral blood leukocytes of patients with sepsis was investigated to assess the correlations with leukocyte, E-selectin, ICAM-1 and disease severity. The expression of microRNA-23b in peripheral blood leukocytes from 87 patients with sepsis, 50 patients with systemic inflammatory response syndrome (SIRS) and 50 normal controls were measured by reverse transcription-quantitative PCR (RT-qPCR), and stability of microRNA-23b was evaluated. Enzyme-linked immunosorbent assay (ELISA) was used to detect E-selectin and ICAM-1. Sequential organ failure assessment (SOFA) scoring system was used to assess the severity of sepsis patients. Correlation analysis was performed between microRNA-23b and the total number of white blood cells (WBC), E-selectin, ICAM-1, and SOFA scores. Compared with the normal control group, the expression level of microRNA-23b in the sepsis group was significantly decreased (P<0.05), and WBC and E-selectin were significantly increased (P<0.05). ICAM-1 level in the sepsis and the SIRS groups was significantly higher than that in the control group (P<0.05), and it is also higher in the sepsis group than in the SIRS group. In the sepsis group, the expression level of microRNA-23b in the death group was significantly lower than that in the survivor group (P<0.05), while the level of E-selectin, ICAM-1, and SOFA scores were significantly higher in the death group than in the survivor group (P<0.05), while there was no significant difference in WBC between the groups (P>0.05). The expression level of microRNA-23b in patients with sepsis was significantly negatively correlated with SOFA scores, E-selectin, and ICAM-1 (r=-0.633, -0.585, and -0.439, respectively, P<0.05). The expression of microRNA-23b in peripheral blood of patients with sepsis is related to the manifestation of the inflammatory state, and can be used to judge the severity and prognosis of patients with this disease.