1056 GRANULOCYTE ADHERENCE IN NEWBORN INFANTS

Abstract

Adherence to the vascular endothelium is an important cell property of the granulocyte which influences the degree of inflammation and host defense against bacterial invasion. In order to determine if granulocyte adherence (GA) is altered during the newborn period, we studied 52 full-term healthy neonates during their first week of life. The neonates were chosen from mothers who had uncomplicated pregnancies and were receiving no antenatal medications. All neonates had received 1 mg of Vitamin K intramuscularly after birth. GA was assayed by modified nylon fiber columns. The mean GA ± SEM for 80 healthy adult volunteers was 69.6 ± 1.2% while the GA for the 52 newborns was 92.0 ± 0.9%. There was a significant difference between the two populations (p < 0.01). There was no significant influence of either race or sex in both adult and neonatal populations studied. A small but significant negative correlation between GA and hematocrit existed for the adults (r= -0.242, p < 0.05) but no such correlation was demonstrable for the neonatal group. There was no significant correlation for the adults between GA and total granulocyte counts, and a small but significant negative correlation was noted for the neonates (r= -0.285, p < 0.05). It is thus concluded that granulocyte adherence is markedly enhanced in the newborn infant as compared to the adult; it is further speculated that such enhanced adherence to the endothelium possibly contributes to the defective chemotaxis seen in newborn infants.