title: S100B urine concentrations in late preterm infants are gestational age and gender dependent.
abstract: BACKGROUND
  Late preterm deliveries (LP, between 34 and 36wks), have considerably increased in the last decades. About 20-25% of LP infants who require intensive care and morbidity on public health are of great magnitude. Therefore, we aimed at offering a reference curve in LP period of a well-established neurotrophic and brain damage marker namely S100B protein.
  
  
  METHODS
  We collected, between December 2009 and March 2012, urine samples, at first void (within 6-hours from birth) for S100B assessment, in 277 healthy LP infants consecutively admitted to our units. Standard clinical and laboratory monitoring parameters were also recorded. S100B was measured by using a commercially available immunoluminometric assay.
  
  
  RESULTS
  S100B pattern in LP infants was characterized by a slight decrease in protein's concentration from 34 to 35wks. From 35wks onwards S100B started to increase reaching a significant difference (P=0.008) at 36wks. When corrected for gender, significantly higher (P<0.01, for all) S100B concentrations in female were observed from 34 to 36wks. Polynomial type-1 regression analysis showed a significant correlation (R=-0.05; P<0.001) between gestational age and S100B in LP infants considering either the whole study population or when corrected for gender.
  
  
  CONCLUSIONS
  S100B in LP infants is gestational age and gender dependent. The present reference curve, for S100B in LP period, offers additional support to protein's neurotrophic role and suggests that gestational age and gender have to be taken into due account, whenever S100B is measured, in order to avoid bias factors.
authors.affiliation: Dept. Critical Care and Perinatal Medicine G. Gaslini Children's Hospital, Genoa, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Sannia
authors.forename: Francesco Maria
authors.initials: FM
authors.lastname: Risso
authors.forename: Luc J I
authors.initials: LJ
authors.lastname: Zimmermann
authors.forename: Antonio W D
authors.initials: AW
authors.lastname: Gavilanes
authors.forename: Hans J
authors.initials: HJ
authors.lastname: Vles
authors.forename: Diego
authors.initials: D
authors.lastname: Gazzolo
mesh_terms: D000328:Adult; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000652:urine*; D008297:Male; D009414:Nerve Growth Factors / Q000652:urine*; D011247:Pregnancy; D012016:Reference Values; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000652:urine*; D012727:Sex Characteristics; D013997:Time Factors
chemical_list: D009414:Nerve Growth Factors; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; C579160:S100B protein, human