Brain-specific NSE and S-100 proteins in umbilical blood after normal delivery

Background: To determine normal blood levels of brain-specific proteins S-1 00 and neuron specific enolase (NSE) in healthy newborns and their mothers following uncomplicated birth. Methods: Umbilical artery and vein blood and maternal venous blood was collected at 112 consecutive uncomplicated deliv eries. Venous blood samples were taken from 18 of the neonates 3 days after birth. S-100 and NSE were analyzed quantitatively by double antibody immun oluminometric assay (Sangtec Medical AB. Sweden). Results: Compared with ad ults, healthy neonates had higher levels of both S-100 and NSE. For S-100, median levels (range) were 1.10 mug/l (0.38-5.50 mug/l) and 0.98 mug/l (0.4 3-2.70 mug/l) in umbilical artery and vein, respectively. For NSE, median l evels (range) in umbilical artery blood and vein were 27 mug/l (10-140 mug/ l) and 10.75 mug/l (8.80-greater than or equal to 200 mug/l) respectively. The maternal venous blood levels of both S-100 and NSE were significantly l ower than in their infants. At 3 days of life, neonatal venous levels of th e proteins were still high: S-100, 0.48-9.70 mug/l; NSE, 17-greater than or equal to 200 mug/l. In contrast to adults, haemolysis affected the S-100 l evels in umbilical blood significantly. Conclusion: Concentrations of both S-100 and NSE in blood are greater in newborns after normal birth than in h ealthy adults. The higher levels in umbilical artery blood than in umbilica l vein blood ale consistent with a fetal origin of these proteins. High lev els in venous blood at 3 days of life suggest that the high levels at birth are not related to the birth process but reflect a high activity of these proteins during fetal development. (C) 2001 Elsevier Science B.V. All right s reserved.