Monocytes Expressing Tissue Factor as a Diagnostic Marker for Neonatal Sepsis

Abstract

INTRODUCTION: For neonatal sepsis, several clinical and laboratory parameters have been proposed for its diagnosis but with variable sensitivity and specificity. The bacterial products in sepsis, including endotoxin, induce the production of proinflammatory cytokines that evoke the expression of tissue factor (TF) on monocytes and endothelial cells. OBJECTIVE: Our goal was to estimate the percentage of monocytes that express TF (TF%) by flow cytometry in patients with neonatal sepsis and to delineate its significance in diagnosing neonatal sepsis. METHODS: Twenty-seven neonates with neonatal sepsis and positive blood-culture results were recruited and evaluated clinically for their risk factors. Laboratory investigations including obtaining complete blood count and C-reactive protein level and estimation of the monocytes' TF expression by flow cytometry were performed. Twenty-four normal newborns were included as controls for the laboratory data. RESULTS: The monocytes that expressed TF% of the studied patients was significantly higher than that of the controls (P = .0001). The level of TF% was significantly influenced positively by premature rupture of membranes, multiplicity, white blood cell (WBC) count, staff/segment ratio, and C-reactive protein level and negatively by gestational age, body weight, and platelet count. The sensitivity and overall accuracy of the TF% were higher than those of the staff/segment ratio and the WBC count for diagnosing neonatal sepsis. The areas under the receiver operating characteristic curve of TF%, staff/segment ratio, and WBC count were 0.84, 0.79, and 0.60, respectively. CONCLUSIONS: The monocytes expressing TF% is a promising diagnostic and prognostic marker of infection in neonatal sepsis with high sensitivity and overall accuracy. Adding the estimation of monocytes expressing TF% to the sepsis screen may improve the diagnosis of neonatal sepsis.

Assessment of agreement between EXTEM and NATEM thromboelastometry measurement assays in critically ill neonates

“…Examples of endogenous activation of coagulation include expression of tissue factor on circulating blood cells. This is evident in septic patients as in our study, in which expression of tissue factor on circulating blood cells is mediated through several different mechanisms including bacterial toxins and pro‐inflammatory cytokines 39–42 . Furthermore, NATEM assay is more sensitive to heparin like substances than the EXTEM assay 14 .…”

“…This is evident in septic patients as in our study, in which expression of tissue factor on circulating blood cells is mediated through several different mechanisms including bacterial toxins and pro-inflammatory cytokines. [39][40][41][42] Furthermore, NATEM assay is more sensitive to heparin like substances than the EXTEM assay. 14 These substances are detected in the circulation of critically ill neonates due to endothelial cell damage and glycocalyx degradation, which is highly involved in the pathogenesis of RDS, hypoxia and sepsis.…”