Urinary S-100B concentrations in term and preterm infants at risk for brain damage.
BACKGROUND
Elevated serum concentrations of S-100B, a 21-kDa protein expressed in astroglial cells, has been used to assess cerebral damage after head trauma, infection, ischemia, and perinatal asphyxia.


OBJECTIVE
As S-100B is eliminated by the kidneys, we investigated the feasibility of measuring S-100B in urine of newborns with severe perinatal asphyxia, and in very low birth weight (VLBW) preterm infants at risk for neurodevelopmental impairment.


METHODS
We first analyzed urine samples of 8 term or near-term newborns without major medical problems, followed by urine samples of 2 term newborns with severe birth asphyxia, and finally urine samples of 8 VLBW (gestational age 24-28 weeks) infants collected every 4 h for up to 10 days.


RESULTS
Urinary S-100B concentrations in 8 term or near-term newborns without major medical problems were consistently <1 microg/l. In 2 term newborns with severe asphyxia (Apgar 0/0/0 and 0/2/4) who subsequently had widespread cerebral damage on magnetic resonance imaging, peak urinary S-100B concentrations on the first day of life were 28.1 and 28.4 microg/l, respectively. In 5/8 VLBW infants, urinary S-100B was> microg/l in samples obtained on the first day of life (range 1.2-44.9 microg/l, median 6.8 microg/l). Peak S-100B in urine samples collected during the first 12 h of life were negatively related to gestational age (R(s)=-0.882, p=0.009). Three of the 8 preterm infants had peak urinary concentrations>0 microg/l but neither ultrasound signs of brain damage nor neurodevelopmental delay at 1 year corrected age.


CONCLUSIONS
The determination of urinary S-100B concentrations might be helpful in term infants with severe asphyxia, while high urinary S-100B concentrations in preterm infants are to be attributed to immaturity.
Ruetzler
Katharina
K
Department of Neonatology, Charité Campus Virchow-Klinikum, Berlin, Germany. ruetzler@yahoo.com
Bührer
Christoph
C
Grimmer
Ingrid
I
Müller
Christian
C
Nagdyman
Nicole
N
Obladen
Michael
M
D001921:Brain / Q000378:metabolism* / Q000473:pathology*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D009414:Nerve Growth Factors / Q000652:urine*; D047928:Premature Birth / Q000473:pathology* / Q000652:urine*; D012307:Risk Factors; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000652:urine*; D047929:Term Birth
D009414:Nerve Growth Factors; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins