Measurement of plasma concentration of high mobility group box1 (HMGB1) in early neonates and evaluation of its usefulness

High mobility group box 1 (HMGB1), intensively studied in adult patients by several investigators, is suggested to cause potentially fatal conditions such as systemic inflammatory response syndrome (SIRS) and disseminated intravascular coagulation (DIC). However, little is known about the role of this protein in neonates. In total, 173 full-term neonates were divided into 4 groups according to mode of delivery: scheduled cesarean section (group E, n=67), unscheduled cesarean section (group ER, n=10), normal delivery (group N, n=64) and other modes of vaginal delivery (group CN, n=32). HMGB1 concentration in umbilical cord blood and plasma samples collected 5days after birth were compared among these 4 groups. We also attempted to determine a reference value for HMGB1 concentrations in neonates. The HMGB1 reference value in neonates was 2.0–35.3ng/ml in groups E and N (n=131). The concentration was significantly higher in group ER than in group E (P=0.00022), and was also higher in group CN than in group N (P=0.00721). To our knowledge, this study is the first to determine a reference value for HMGB1 concentrations in neonates. We also revealed significantly elevated HMGB1 concentrations in association with ischemic reperfusion injury caused by certain delivery modes. ► HMGB1 concentration in umbilical cord blood and plasma samples collected 5days after birth were measured. ► The HMGB1 reference value in neonates was found to be 2.0–35.3ng/ml. ► The concentration was significantly higher in unscheduled cesarean section group.