Volume, Conductivity and Scatter parameters of Neutrophils in Neonatal Sepsis – Is it a Cost-Effective Tool?

Background: Early diagnosis of neonatal sepsis is quite challenging. I/T ratio (immature to mature neutrophil ratio) is a highly sensitive marker of sepsis but is time-consuming and subjective. Off late, volume conductivity and scatter (VCS) of neutrophils are among the newer parameters available for screening a septic neonate. This study aimed to determine the correlation between the I/T ratio and VCS parameters in neonatal sepsis and estimate a cut-off value of VCS parameters to diagnose neonatal sepsis using receiver operating curve analysis. Materials and Methods: This prospective observational study was conducted by the Department of Pathology and Neonatology from April 2019 to March 2020 in a tertiary care center. A total of 110 newborns were included in this study and were divided into two groups (probable sepsis and sepsis). Data were collected from the hospital database, and analysis was done using SPSS software. Correlation between the I/T ratio and VCS parameters was done using Spearman’s correlation. Results were expressed as mean ± standard deviation (SD). A P-value of <0.05 was considered statistically significant.  Results: Correlation between the I /T ratio and VCS parameters showed negative correlation values of -0.22, -0.23, and +0.39 (P-values of 0.0198, 0.0153, and <0.0001) for mean neutrophil conductivity (MNC), mean neutrophil scatter (MNS) and mean neutrophil volume (MNV) respectively. MNV with a cut-off of > 156.4 had sensitivity and a negative predictive value of 100 % in the diagnosis of sepsis and was found to be higher in the sepsis group when compared to the probable sepsis group. Conclusion: Based on the significant difference in VCS parameters of neutrophils in the sepsis group, this aids as an additional marker for the early diagnosis of neonatal sepsis.