S100B urine concentrations in late preterm infants are gestational age and gender dependent

BackgroundLate preterm deliveries (LP, between 34 and 36 wks), 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.MethodsWe 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.ResultsS100B pattern in LP infants was characterized by a slight decrease in protein's concentration from 34 to 35 wks. From 35 wks onwards S100B started to increase reaching a significant difference (P = 0.008) at 36 wks. When corrected for gender, significantly higher (P < 0.01, for all) S100B concentrations in female were observed from 34 to 36 wks. 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.ConclusionsS100B 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.

► Late preterm infants who require intensive care and morbidity are of great magnitude.
► We offer a reference curve in late preterm period of neurotrophic S100B protein.
► We collected urine samples at first void in 277 healthy late preterm infants.
► S100B in late preterm infants is gestational age and gender dependent.
► Whenever S100B is measured bias factors have to be taken into due account.