Early predictors of abnormal MRI patterns in asphyxiated infants: S100B protein urine levels.

OBJECTIVES: The early detection and stratification of asphyxiated infants at higher risk for impaired neurodevelopment is challenging. S100B protein is a well-established biomarker of brain damage, but lacks conclusive validation according to the "gold standard" methodology for hypoxic-ischemic encephalopathy (HIE) prognostication, i.e. brain MRI. The aim of the present study was to investigate the predictive role of urinary S100B concentrations, assessed in a cohort of HIE infants receiving therapeutic hypothermia (TH), compared to brain MRI. METHODS: Assessment of urine S100B concentrations was performed by immunoluminometric assay at first void and at 4, 8, 12, 16, 20, 24, 48, 72, 96, 108 and 120-h after birth. Neurologic evaluation, routine laboratory parameters, amplitude-integrated electroencephalography, and cerebral ultrasound were performed according to standard protocols. Brain MRI was performed at 7-10 days of life. RESULTS: Overall, 74 HIE neonates receiving TH were included in the study. S100B correlated, already at first void, with the MRI patterns with higher concentrations in infants with the most severe MRI lesions. CONCLUSIONS: High S100B urine levels soon after birth constitute trustable predictors of brain injury as confirmed by MRI. Results support the reliability of S100B in clinical daily practice and open the way to its inclusion in the panel of parameters used for the selection of cases suitable for TH treatment.

S100B protein, cerebral ultrasound and magnetic resonance imaging patterns in brain injured preterm infants.

OBJECTIVES: The early detection of preterm infants (PI) at risk for intraventricular hemorrhage (IVH) and neurological sequelae still constitutes an unsolved issue. We aimed at validating the role of S100B protein in the early diagnosis and prognosis of IVH in PI by means of cerebral ultrasound (CUS) and magnetic resonance imaging (MRI) today considered standard of care procedures. METHODS: We conducted an observational case-control study in 216 PI of whom 36 with IVH and 180 controls. Standard clinical, laboratory, radiological monitoring procedures and S100B urine measurement were performed at four time-points (first void, 24, 48, 96 h) after birth. Cerebral MRI was performed at 40-42 weeks of corrected gestational age. RESULTS: Elevated (p<0.001, for all) S100B levels were observed in the IVH group at all monitoring time-point particularly at first void when standard monitoring procedures were still silent or unavailable. S100B measured at first void correlated (p<0.001) with the grade of hemorrhage by means of CUS and with the site and extension of neurological lesion (p<0.001, for all) as assessed by MRI. CONCLUSIONS: The present results showing a correlation among S100B and CUS and MRI offer additional support to the inclusion of the protein in clinical daily management of cases at risk for IVH and adverse neurological outcome. The findings open the way to further investigations in PI aimed at validating new neurobiomarkers by means of S100B.

Monitoring the effectiveness of hypothermia in perinatal asphyxia infants by urinary S100B levels.

Background Perinatal asphyxia is a major cause of mortality and morbidity in neonates: The aim of the present study was to investigate, by means of longitudinal assessment of urinary S100B, the effectiveness of hypothermia, in infants complicated by perinatal asphyxia and hypoxic-ischemic encephalopathy. Methods We performed a retrospective case-control study in 108 asphyxiated infants, admitted to nine tertiary departments for neonatal intensive care from January 2004 to July 2017, of whom 54 underwent hypothermia treatment and 54 did not. The concentrations of S100B protein in urine were measured using an immunoluminometric assay at first urination and 4, 8, 12, 16, 20, 24, 48, 72, 96, 108 and 120 h after birth. The results were correlated with the achievement of S100B levels within normal ranges at 72 h from hypothermia treatment. Routine laboratory parameters, longitudinal cerebral function monitoring, cerebral ultrasound and neurologic patterns were assessed according to standard protocols. Results Higher S100B concentrations were found in hypothermia-treated infants in both moderate (up to 12 h) and severe (up to 24 h) hypoxic-ischemic encephalopathy. S100B levels returned to normal ranges starting from 20 h of hypothermia treatment in moderate and from 36 h in severe hypoxic-ischemic encephalopathy. Conclusions The present results offer additional support to the usefulness of longitudinal neuro-biomarkers monitoring in asphyxiated infants treated by hypothermia. The pattern of S100B concentrations during hypothermia supports the need for further investigations aimed at reconsidering the time-window for patient recruitment and treatment, and the optimal duration of the cooling and rewarming phases of the hypothermia procedure.

Urine S100 BB and A1B dimers are valuable predictors of adverse outcome in full-term asphyxiated infants.

AIM: To investigate whether S100A1B and BB dimers are predictors of early perinatal death in newborns with perinatal asphyxia (PA). METHODS: The study compared 38 full-term newborns with PA [neonatal death n = 11; hypoxic ischaemic encephalopathy (HIE): n = 27] with a control group of 38 healthy infants. Clinical and laboratory parameters were recorded at eight time points and urine collected for S100B assessment. Multivariate analysis was performed in order to analyse the influence of various clinical parameters on the occurrence of neonatal death. RESULTS: A1B and BB in PA nonsurvivor infants were significantly higher (p < 0.001) than in controls at all monitoring time points. BB at first void (cut-off>42 ng/L) was the best predictor of early neonatal death (p < 0.05) of all the clinical and laboratory parameters studied. CONCLUSION: These results suggest that S100s are valuable predictors of adverse outcome in PA infants. It is also suggested that these biomarkers be used in daily clinical practice, due to their low cost and stress, reproducibility and the possibility of longitudinal monitoring.

Perinatal asphyxia: kidney failure does not affect S100B urine concentrations.

BACKGROUND: S100B protein is a well-established marker of brain damage. Its importance in urine assessment is the convenience of a collection and sampling procedure that can be repeated without risk for the newborn. Since S100B is mainly eliminated by the kidneys and perinatal asphyxia (PA) is often associated with kidney failure we investigated whether S100B release might be kidney-mediated, thereby modifying the protein's reliability as a brain-damage marker. METHODS: We examined a cohort of healthy (n=432) and asphyxiated newborns (n=32) in whom kidney function parameters (blood urea and creatinine concentrations and urine gravity) and urine S100B concentrations were assessed in the first hours after birth. Data were analyzed by multiple logistic regression analysis with S100B as independent variable among a variety of clinical and laboratory monitoring parameters. RESULTS: S100B urine concentrations were significantly higher (P<0.01) in PA newborns than controls. No significant correlations (P>0.05, for all) between total urine S100B levels and kidney function parameters such as creatinine (r=0.03), urea (r=0.04) and urine gravity (r=0.06) were found. Multiple logistic regression analysis of a series of clinical and laboratory monitoring parameters (odds ratio at sampling: 9.47) with S100B as independent variable showed a positive significant correlation only between S100B levels (P<0.001) and the occurrence of PA. CONCLUSION: The present study shows that altered kidney function is not an adverse and/or confounding factor in urine S100B assessment and marks a new step towards the introduction of longitudinal monitoring of brain constituents in clinical practice.

Increased maternal/fetal blood S100B levels following systemic endotoxin administration and periventricular white matter injury in preterm fetal sheep.

OBJECTIVE: Intrauterine infection is suggested to cause perinatal brain white matter injury. In the current study, we evaluated whether S100B, a brain damage marker, may be also assessed in maternal bloodstream after white matter injury induced by fetal intravenous application of lypopolisaccharide (LPS) endotoxin. METHODS: Fourteen fetal sheeps were chronically catheterized at a mean gestational age of 107 days. Three days after surgery, fetuses (n = 7) received 500 ng of LPS or 2 mL 0.9% saline (n = 7) intravenously (IV). Lypopolisaccharide and placebo groups were monitored by continuous hemodynamic data recordings and at 6 predetermined time points (control value; 3, 6, 24, 48, and 72 hours after LPS/placebo administration) blood was drawn for laboratory parameters and S100B assessment. Brain damage was evaluated by light microscopy after Klüver-Barrera staining. Selected areas of the periventricular white matter were also examined by electron microscopy. RESULTS: White matter injury was detected in all LPS-treated fetuses, whereas no abnormalities were seen in control animals or in LPS-treated mothers. Maternal and fetal S100B protein levels were significantly higher in the LPS group than in the control group at all monitoring time points (P < .001). The highest fetal-maternal S100B levels were observed at 3-hour time-point (P < .001). CONCLUSIONS: We found that S100B protein is increased in the maternal district in presence of fetal periventricular brain white matter injury induced by endotoxin. The present data offer additional support for S100B assessment in the maternal circulation in pregnancies complicated by intrauterine infection at risk of white matter injury.

Diagnostic accuracy of S100B urinary testing at birth in full-term asphyxiated newborns to predict neonatal death.

BACKGROUND: Neonatal death in full-term infants who suffer from perinatal asphyxia (PA) is a major subject of investigation, since few tools exist to predict patients at risk of ominous outcome. We studied the possibility that urine S100B measurement may identify which PA-affected infants are at risk of early postnatal death. METHODOLOGY/PRINCIPAL FINDINGS: In a cross-sectional study between January 1, 2001 and December 1, 2006 we measured S100B protein in urine collected from term infants (n = 132), 60 of whom suffered PA. According to their outcome at 7 days, infants with PA were subsequently classified either as asphyxiated infants complicated by hypoxic ischemic encephalopathy with no ominous outcome (HIE Group; n = 48), or as newborns who died within the first post-natal week (Ominous Outcome Group; n = 12). Routine laboratory variables, cerebral ultrasound, neurological patterns and urine concentrations of S100B protein were determined at first urination and after 24, 48 and 96 hours. The severity of illness in the first 24 hours after birth was measured using the Score for Neonatal Acute Physiology-Perinatal Extension (SNAP-PE). Urine S100B levels were higher from the first urination in the ominous outcome group than in healthy or HIE Groups (p<0.001 for all), and progressively increased. Multiple logistic regression analysis showed a significant correlation between S100B concentrations and the occurrence of neonatal death. At a cut-off >1.0 microg/L S100B had a sensitivity/specificity of 100% for predicting neonatal death. CONCLUSIONS/SIGNIFICANCE: Increased S100B protein urine levels in term newborns suffering PA seem to suggest a higher risk of neonatal death for these infants.