Predictive value of brain-specific proteins in serum for neurodevelopmental outcome after birth asphyxia

A biochemical feedback signal for hypothermia treatment for neonatal hypoxic-ischemic encephalopathy: focusing on central nervous system proteins in biofluids

Hypothermia has been widely used to treat moderate to severe neonatal hypoxic-ischemic encephalopathy (HIE), yet evaluating the effects of hypothermia relies on clinical neurology, neuroimaging, amplitude-integrated electroencephalography, and follow-up data on patient outcomes. Biomarkers of brain injury have been considered for estimating the effects of hypothermia. Proteins specific to the central nervous system (CNS) are components of nervous tissue, and once the CNS is damaged, these proteins are released into biofluids (cerebrospinal fluid, blood, urine, tears, saliva), and they can be used as markers of brain damage. Clinical reports have shown that CNS-specific marker proteins (CNSPs) were early expressed in biofluids after brain damage and formed unique biochemical profiles. As a result, these markers may serve as an indicator for screening brain injury in infants, monitoring disease progression, identifying damage region of brain, and assessing the efficacy of neuroprotective measures. In clinical work, we have found that there are few reports on using CNSPs as biological signals in hypothermia for neonatal HIE. The aim of this article is to review the classification, origin, biochemical composition, and physiological function of CNSPs with changes in their expression levels after hypothermia for neonatal HIE. Hopefully, this review will improve the awareness of CNSPs among pediatricians, and encourage future studies exploring the mechanisms behind the effects of hypothermia on these CNSPs, in order to reduce the adverse outcome of neonatal HIE.

Value of brain damage biomarkers in cerebrospinal fluid in neonates with hypoxic-ischemic brain injury

Hypoxic-ischemic encephalopathy is one of the leading causes of death and neurological disability worldwide. A key issue in neonates with hypoxic-ischemic encephalopathy is accurately establishing the occurrence and severity of brain lesions soon after a perinatal hypoxic-ischemic event. This is crucial to help with prognosis; guide clinical decision-making, including the use of other therapies; and improve family counseling. Neurobiochemical markers may offer a quantitative approximation for estimating the severity of brain damage and identifying infants who have a high risk of further neurological disability. In addition, they should help identify those neonates who would benefit most from the implementation of other neuroprotective and neuroreparative interventions. Despite considerable progress in this area, relatively few studies have been aimed at examining the clinical utility of brain-specific proteins in cerebrospinal fluid, an important opening to characterizing pathological phenomena associated with hypoxic-ischemic brain injury.

Bedside and laboratory neuromonitoring in neonatal encephalopathy

Several bedside and laboratory neuromonitoring tools are currently used in neonatal encephalopathy (NE) to assess 1) brain function [amplitude-integrated electroencephalogram (aEEG) and EEG], 2) cerebral oxygenation delivery and consumption [near-infrared spectroscopy (NIRS)] and 3) blood and cerebrospinal fluid biomarkers. The aim of the review is to provide the role of neuromonitoring in understanding the development of brain injury in these newborns and better predict their long-term outcome. Simultaneous use of these monitoring modalities may improve our ability to provide meaningful prognostic information regarding ongoing treatments. Evidence will be summarized in this review for each of these modalities, by describing (1) the methods, (2) the clinical evidence in context of NE both before and with hypothermia, and (3) the research and future directions.

Can we delineate brain injury in full-term neonates using serum biomarkers?

OBJECTIVE: Early identification of neonates at risk of neurological impairment is particularly important for the bedside clinician. Clinical value of S100b and neuron-specific enolase in neonates has not been yet established. We investigated their kinetics and possible early clinical utility in neonatal encephalopathy (NE).STUDY DESIGN: 36 full-term neonates (13 with moderate/severe encephalopathy, 11 with mild encephalopathy, 12 controls) were enrolled and studied prospectively. Serum S100b and neuron-specific enolase (NSE) were measured serially on days(d) 1, 3, 9 and 18 of life. Brain MRI and long-term neurodevelopmental outcome were also assessed.RESULT: Neonates with moderate/severe encephalopathy had significantly increased S100b (d1) and NSE levels (d1, d3, d9) compared to controls. Neuron-specific enolase significantly correlated with the degree of encephalopathy, and a cutoff of 38.8 μg/l (d1) accurately predicted moderate/severe encephalopathy. S100b (d1) cutoff points of 1.6 μg/l and 11.4 μg/l prognosticated severe encephalopathy and death/cerebral palsy, respectively. Both biomarkers correlated well with neuroimaging and Bayley-III scores.CONCLUSION: Combined clinical, laboratory, imaging and neurodevelopmental data indicate that serum S100b and NSE can be useful biomarkers for the diagnosis and prognosis of neonatal brain injury, providing useful information to the bedside clinician.

Neuronal Biomarkers in Predicting Neurodevelopmental Outcome in Term Babies with Perinatal Asphyxia

OBJECTIVE

To assess whether serum levels of neuronal biomarkers (S100 calcium-binding protein B and Neuron specific enolase) correlate with the neurodevelopmental outcome of term neonates at 18 mo who had hypoxic ischemic encephalopathy and underwent therapeutic hypothermia.

METHODS

This randomized controlled trial was conducted in a tertiary care teaching hospital, south India. There were 162 term infants with moderate to severe hypoxic ischemic encephalopathy who were randomized into 2 groups (Group A and B). Neonates in Group A and B received normothermia and therapeutic hypothermia respectively. Serum levels of neuronal biomarkers were estimated at 0, 24 (±1) and 72 (±1) h after birth using sandwich ELISA in both groups. All neonates were carefully monitored till discharge. Infants who survived the neonatal period were followed up in the high risk clinic for 18 mo and neurodevelopmental assessment was done using Developmental Assessment Scale for Indian Infants (DASII). Neurodevelopmental outcomes between the two groups were compared using Chi square test and neuronal biomarker levels between the groups were compared using Mann Whitney test.

RESULTS

The baseline maternal and neonatal characteristics in both groups were comparable. There was statistically insignificant lesser mortality in therapeutic hypothermia group compared to normothermia group with Risk Ratio (RR): 0.82 (28.2% vs. 34.5%, 95% CI: 0.52-1.29, p = 0.38). Among the survivors, children in therapeutic hypothermia group had better motor and mental scores compared to those in normothermia group at 18 mo. There was no significant correlation between S100B and Neuron specific enolase levels and neurodevelopmental outcome.

CONCLUSIONS

Serum levels of neuronal biomarkers (S100B and Neuron specific enolase) do not correlate with the long term neurodevelopmental outcome among these infants.

Cerebrospinal fluid levels of neuron-specific enolase predict the severity of brain damage in newborns with neonatal hypoxic-ischemic encephalopathy treated with hypothermia

Objectives

To investigate whether cerebrospinal fluid levels of neuron-specific enolase (CSF-NSE) during the first 72 hours correlate with other tools used to assess ongoing brain damage, including clinical grading of hypoxic-ischemic encephalopathy (HIE), abnormal patterns in amplitude integrated electroencephalography (aEEG), and magnetic resonance imaging (MRI), as well as with the neurodevelopmental outcomes at two years of age.

Material and methods

Prospective observational study performed in two hospitals between 2009 and 2011. Forty-three infants diagnosed with HIE within 6 hours of life were included. HIE was severe in 20 infants, moderate in 12, and mild in 11. Infants with moderate-to-severe HIE received whole-body cooling. Both the HIE cohort and a control group of 59 infants with suspected infection underwent measurement of CSF-NSE concentrations at between 12 and 72 hours after birth. aEEG monitoring was started at admission and brain MRI was performed within the first 2 weeks. Neurodevelopment was assessed at 24 months.

Results

The HIE group showed higher levels of CSF-NSE than the control group: median 70 ng/ml (29; 205) vs 10.6 ng/ml (7.7; 12.9); p <0.001. Median levels of CSF-NSE in infants with severe, moderate, and mild HIE were 220.5 ng/ml (120.5; 368.8), 45.5 ng/ml (26, 75.3), and 26 ng/ml (18, 33), respectively. CSF-NSE levels correlated were significantly higher in infants with seizures, abnormal aEEG, or abnormal MRI, compared to those without abnormalities. Infants with an adverse outcome showed higher CSF-NSE levels than those with normal findings (p<0.001), and the most accurate CSF-NSE cutoff level for predicting adverse outcome in the whole cohort was 108 ng/ml and 50ng/ml in surviving infants.

Conclusions

In the era of hypothermia, CSF-NSE concentrations provides valuable information as a clinical surrogate of the severity of hypoxic-ischemic brain damage, and this information may be predictive of abnormal outcome at two years of age.

The Role of S100B Protein at 24 Hours of Postnatal Age as Early Indicator of Brain Damage and Prognostic Parameter of Perinatal Asphyxia

Introduction. S100B protein is a cytosolic calcium-binding protein with a molecular weight of 21 kDa, which is present in various cells and concentrated mainly in the glial cells, which play a vital role in the maintenance of cellular homeostasis in the central nervous system. It is possible that increased S100B protein level might be considered as sensitive and specific indicator to predict early brain damage. Aim. To investigate the prognostic value of serum S100B protein in neonates with perinatal asphyxia (PA) at 24 hours of postnatal age. Methods. A systematic review was performed. Inclusion criteria were studies including data of neonates with PA, monitored with serum S100B, and with neurodevelopmental follow-up of at least 2 weeks. The period of bibliographic search was until January 2017. The consulted databases were MEDLINE, PsycINFO, and Embase. A combination of the following subject headings and keywords was adapted for each electronic database: “perinatal asphyxia,” “hypoxic ischemic encephalopathy,” “hypoxia-ischemia, brain,” and “S100B.” Meta-Disc1.4 software was used. Results. From the 1620 articles initially identified, 6 were finally included and reviewed. The overall diagnostic sensitivity of serum S100B was 0.80 (95% confidence interval [CI] = 0.68-0.88) and the specificity was 0.79 (95% CI = 0.70-0.87). But there was lower predictability value, that is, the positive likelihood ratio was only 3.26 (95% CI 1.74-6.12) and the negative likelihood ratio was 0.32 (95% CI = 0.20-0.5). The diagnostic odds ratio was 12.40 (95% CI = 4.66-33.0). Conclusion. Increased serum S100B level at 24 hours of postnatal life can demonstrate brain damage, but it should not be the only one used to predict PA outcome.

A Pilot Study of Soluble Form of LOX-1 as a Novel Biomarker for Neonatal Hypoxic-Ischemic Encephalopathy

OBJECTIVE

To evaluate the soluble form of lectin-like oxidized low-density lipoprotein receptor-1 (sLOX-1) as a biomarker of severity staging and prognosis in neonatal hypoxic-ischemic encephalopathy (HIE).

STUDY DESIGN

We performed an observational study enrolling 27 infants with HIE and 45 control infants of gestational age ≥36 weeks and birth weight ≥1800 g. The HIE criteria were pH ≤7.0 or a base deficit ≥16 mmol/L within 60 minutes after birth, and a 10-minute Apgar score ≤5 or resuscitation time ≥10 minutes. HIE severity was evaluated using modified Sarnat staging. We measured plasma sLOX-1 level and assessed general and neurologic signs at discharge, and classified infants with no neurosensory impairments as intact survival.

RESULTS

sLOX-1 level within 6 hours after birth was correlated with the severity of HIE. sLOX-1 differentiated moderate-severe HIE (median, 1017 pg/mL; IQR, 553-1890 pg/mL) from mild HIE (median, 339 pg/mL; IQR, 288-595 pg/mL; P = .007). The sensitivity and specificity of the differentiation with a cutoff value of ≥550 pg/mL were 80.0% and 83.3%, respectively. In 19 infants with therapeutic hypothermia, a sLOX-1 cutoff value of <1000 pg/mL differentiated intact survival (median, 761 pg/mL; IQR, 533-1610 pg/mL) from death or neurosensory impairment (median, 1947 pg/mL; IQR, 1325-2506 pg/mL; P = .019) with 100% specificity and a positive predictive value.

CONCLUSION

sLOX-1 may be a useful biomarker of neonatal HIE for severity staging and outcome prediction. Further investigations will facilitate its clinical use.

The Ca2+-Binding S100B Protein: An Important Diagnostic and Prognostic Neurobiomarker in Pediatric Laboratory Medicine

In recent decades a significant scientific effort has focused on projects regarding the use of neurobiomarkers in perinatal medicine with a view to understanding the mechanisms that interfere with physiological patterns of brain development and lead to ominous effects in several human diseases. Numerous potential neurobiomarkers have been proposed for use in monitoring high-risk fetuses and newborns, including markers of oxidative stress, neuroproteins, and vasoactive agents. Nonetheless, the use of these markers in clinical practice remains a matter of debate. Recently, the calcium-binding S100B protein has been proposed as being an ideal neurobiomarker, thanks to its simple availability and easy reproducibility, to the possibility of detecting it noninvasively in biological fluids with good reproducibility, and to the possibility of a longitudinal evaluation in relation to reference curves. The present chapter contains an overview of the most significant studies on the assessment of S100B in different biological fluids as a trophic factor and/or marker of brain damage in high-risk fetuses and newborns.

Biomarkers in neonatal hypoxic-ischemic encephalopathy-Review of the literature to date and future directions for research

The widespread introduction of therapeutic hypothermia as a standard of care in hypoxic-ischemic encephalopathy (HIE) has brought increasing pressure on clinicians to make an early and accurate assessment of the degree of hypoxic injury (HI) that has occurred and the severity of the encephalopathy that will ensue. No single blood-based marker is currently robust enough to detect significant HI or predict outcome. However, research in the field has been active in the last 10 years and we know that HIE is associated with predictable alterations in the expression of a number of inflammatory proteins, neuron-specific proteins, metabolite pathways, and microRNA. These alterations evolve quickly over the first hours and days of life. Predictive power varies depending on the timing of measurement of the biomarker, the sample type, and the case mix of the cohort examined. Combining clinical data with biochemical measurements is currently the most likely path toward improved detection and prediction of outcome in neonatal HIE.

Mild hypoxic ischaemic encephalopathy and long term neurodevelopmental outcome - A systematic review

AIMS

Hypoxic ischaemic encephalopathy (HIE) remains a significant cause of long term neurodisability despite therapeutic hypothermia (TH). Infants with mild HIE, representing 50% of those with HIE, are perceived as low risk and are currently not eligible for TH [1]. This review examines the available evidence of outcome in term infants with mild HIE.

METHODS

Medline, Embase and Cochrane Clinical Trials databases were searched in March 2017. Studies with well-defined HIE grading at birth and standardised neurodevelopmental assessment at ≥18 months were included. Abnormal outcome was defined as death, cerebral palsy or standardised neurodevelopmental test score more than 1 standard deviation below the mean.

RESULT

Twenty studies were included. Abnormal outcome was reported in 86/341 (25%) of infants. There was insufficient evidence to examine the effect of TH on outcome.

CONCLUSION

A significant proportion of infants with mild HIE have abnormal outcome at follow up.

Systemic and transdermal melatonin administration prevents neuropathology in response to perinatal asphyxia in newborn lambs

Perinatal asphyxia remains a principal cause of infant mortality and long-term neurological morbidity, particularly in low-resource countries. No neuroprotective interventions are currently available. Melatonin (MLT), a potent antioxidant, anti-inflammatory and antiapoptotic agent, offers promise as an intravenous (IV) or transdermal therapy to protect the brain. We aimed to determine the effect of melatonin (IV or transdermal patch) on neuropathology in a lamb model of perinatal asphyxia. Asphyxia was induced in newborn lambs via umbilical cord occlusion at birth. Animals were randomly allocated to melatonin commencing 30 minutes after birth (60 mg in 24 hours; IV or transdermal patch). Brain magnetic resonance spectroscopy (MRS) was undertaken at 12 and 72 hours. Animals (control n = 9; control+MLT n = 6; asphyxia n = 16; asphyxia+MLT [IV n = 14; patch n = 4]) were euthanised at 72 hours, and cerebrospinal fluid (CSF) and brains were collected for analysis. Asphyxia resulted in severe acidosis (pH 6.9 ± 0.0; lactate 9 ± 2 mmol/L) and altered determinants of encephalopathy. MRS lactate:N-acetyl aspartate ratio was 2.5-fold higher in asphyxia lambs compared with controls at 12 hours and 3-fold higher at 72 hours (P < .05). Melatonin prevented this rise (3.5-fold reduced vs asphyxia; P = .02). Asphyxia significantly increased brain white and grey matter apoptotic cell death (activated caspase-3), lipid peroxidation (4HNE) and neuroinflammation (IBA-1). These changes were significantly mitigated by both IV and patch melatonin. Systemic or transdermal neonatal melatonin administration significantly reduces the neuropathology and encephalopathy signs associated with perinatal asphyxia. A simple melatonin patch, administered soon after birth, may improve outcome in infants affected by asphyxia, especially in low-resource settings.

Association between serum interleukin-6 levels and severity of perinatal asphyxia

Background: Perinatal asphyxia is a major cause of neurologic morbidity and mortality in infants. Objective: Determine the serum level of interleukin-6 (IL-6) in neonates with perinatal asphyxia and its relation to the severity of hypoxic-ischemic encephalopathy and short term neurological outcome. Methods: Serum IL-6 levels were measured at birth, and at 24 and 48 hour post-partum in 37 consecutive uninfected neonates with peri-natal asphyxia and 45 randomly selected healthy newborns. Results: Serum IL-6 concentrations in the infants who developed hypoxic-ischemic encephalopathy was 43 folds higher compared to values in the normal infants (p < 0.001) and 1.9 folds higher as compared to infants with asphyxia who did not subsequently develop hypoxic-ischemic encephalopathy (p <0.001). Serum IL-6 concentrations were also related to the degree of hypoxic-ischemic encephalopathy and neurologicaldevelopmental outcomes at the time of discharge. Conclusion: Serum levels of IL-6 increased in neonates with asphyxia, and this was most pronounced in neonates with adverse outcomes.

Plasma Biomarkers of Brain Injury in Neonatal Hypoxic-Ischemic Encephalopathy

OBJECTIVES

To evaluate plasma brain specific proteins and cytokines as biomarkers of brain injury in newborns with hypoxic-ischemic encephalopathy (HIE) and, secondarily, to assess the effect of erythropoietin (Epo) treatment on the relationship between biomarkers and outcomes.

STUDY DESIGN

A study of candidate brain injury biomarkers was conducted in the context of a phase II multicenter randomized trial evaluating Epo for neuroprotection in HIE. Plasma was collected at baseline (<24 hours) and on day 5. Brain injury was assessed by magnetic resonance imaging (MRI) and neurodevelopmental assessments at 1 year. The relationships between Epo, brain-specific proteins (S100B, ubiquitin carboxy-terminal hydrolase-L1 [UCH-L1], total Tau, neuron specific enolase), cytokines (interleukin [IL]-1β, IL-6, IL-8, IL-10, IL-12P70, IL-13, interferon-gamma [IFN-γ], tumor necrosis factor alpha [TNF-α], brain-derived neurotrophic factor [BDNF], monocyte chemoattractant protein-1), and brain injury were assessed.

RESULTS

In 50 newborns with encephalopathy, elevated baseline S100B, Tau, UCH-L1, IL-1β, IL-6, IL-8, IL-10, IL-13, TNF-α, and IFN-γ levels were associated with increasing brain injury severity by MRI. Higher baseline Tau and lower day 5 BDNF were associated with worse 1 year outcomes. No statistically significant evidence of Epo treatment modification on biomarkers was detected in this small cohort.

CONCLUSIONS

Elevated plasma brain-specific proteins and cytokine levels in the first 24 hours of life are associated with worse brain injury by MRI in newborns with HIE. Only Tau and BDNF levels were found to be related to neurodevelopmental outcomes. The effect of Epo treatment on the relationships between biomarkers and brain injury in HIE requires further study.

TRIAL REGISTRATION

ClinicalTrials.gov: 01913340.

Serum copeptin and neuron specific enolase are markers of neonatal distress and long-term neurodevelopmental outcome

The objective of this study was to evaluate the early changes in serial serum levels of copeptin and neuron-specific enolase (NSE) in neonates diagnosed with birth asphyxia, and to determine whether these biomarkers measured in the first 168 hours after birth are predictive of long-term neurodevelopmental outcome. Copeptin and NSE levels were measured from serum samples collected 6, 12, 24, 48, 72, and 168 hours after birth from 75 term neonates diagnosed with hypoxic-ischemic encephalopathy (HIE) and treated with therapeutic hypothermia for 72 hours. In addition, serum copeptin levels after birth were measured from 10 HIE diagnosed neonates, who were randomized to the normothermic arm of the TOBY cohort. All neonates underwent neurodevelopmental assessment using the Bayley Scales of Infant and Toddler Development-II at two years of age. Copeptin levels were highest at 6 hours after birth and steadily decreased, whereas the highest NSE levels were measured at 24 hours after birth. The biomarker levels correlated with blood-gas parameters (base excess, pH and lactate) at 6 and 12 hours after birth. Copeptin and NSE levels in the early postnatal period were significantly higher in neonates with poor outcome compared to those with favorable outcome at two years of age. Furthermore, in the TOBY cohort, copeptin levels were significantly lower in hypothermic compared to normothermic neonates. To conclude, copeptin and NSE measured in the early postnatal period are potential prognostic biomarkers of long-term neurodevelopmental outcome in term neonates diagnosed with HIE and treated with therapeutic hypothermia.

Protein S100B in umbilical cord blood as a potential biomarker of hypoxic-ischemic encephalopathy in asphyxiated newborns

BACKGROUND

Neonatal hypoxic ischemic encephalopathy (HIE) is a devastating condition resulting from a sustained lack of oxygen during birth. The interest in identifying a relevant biomarker of HIE has thrown into limelight the role of protein S100B as a clinical diagnostic marker of hypoxic brain damage in neonates.

AIMS

To evaluate the diagnostic value of protein S100B, measured in umbilical cord blood immediately after birth, as a useful biomarker in the diagnosis of HIE Sarnat stages II-III as well as a marker for long-term mortality and morbidity.

STUDY DESIGN

Protein S100B was analyzed in cord blood sampled at birth from 13 newborns later diagnosed with stage II-III HIE and compared with 21 healthy controls. S100B concentrations were related to cord artery pH, amplitude-integrated electroencephalography (aEEG), stage of HIE, and death/sequelae up to an age of 6years. Both parametric and non-parametric statistics were used with a two-sided P<0.05 considered significant.

RESULTS

The difference in S100B concentration was marginally statistically significant between HIE cases and controls (P=0.056). Cord blood acidosis (P=0.046), aEEG pattern severity (P=0.030), HIE severity (P=0.027), and condition at 6-year follow-up (healthy/permanent sequelae/death; P=0.027) were all related to an increase in S100B concentration.

CONCLUSIONS

Protein S100B in neonates suffering from HIE stages II-III appeared elevated in umbilical cord blood at birth. The S100B concentrations were positively associated to the severity of disease and the risk of suffering from neurodevelopmental sequelae and even death.

Does growth restriction increase the vulnerability to acute ventilation-induced brain injury in newborn lambs? Implications for future health and disease

Fetal growth restriction (FGR) and preterm birth are frequent co-morbidities, both are independent risks for brain injury. However, few studies have examined the mechanisms by which preterm FGR increases the risk of adverse neurological outcomes. We aimed to determine the effects of prematurity and mechanical ventilation (VENT) on the brain of FGR and appropriately grown (AG, control) lambs. We hypothesized that FGR preterm lambs are more vulnerable to ventilation-induced acute brain injury. FGR was surgically induced in fetal sheep (0.7 gestation) by ligation of a single umbilical artery. After 4 weeks, preterm lambs were euthanized at delivery or delivered and ventilated for 2 h before euthanasia. Brains and cerebrospinal fluid (CSF) were collected for analysis of molecular and structural indices of early brain injury. FGRVENT lambs had increased oxidative cell damage and brain injury marker S100B levels compared with all other groups. Mechanical ventilation increased inflammatory marker IL-8 within the brain of FGRVENT and AGVENT lambs. Abnormalities in the neurovascular unit and increased blood-brain barrier permeability were observed in FGRVENT lambs, as well as an altered density of vascular tight junctions markers. FGR and AG preterm lambs have different responses to acute injurious mechanical ventilation, changes which appear to have been developmentally programmed in utero.

Umbilical Cord Blood NOS1 as a Potential Biomarker of Neonatal Encephalopathy

BACKGROUND

There are no definitive markers to aid in diagnosis of neonatal encephalopathy (NE). The purpose of our study was (1) to identify and evaluate the utility of neuronal nitric oxide synthase (NOS1) in umbilical cord blood as a NE biomarker and (2) to identify the source of NOS1 in umbilical cord blood.

METHODS

This was a nested case-control study of neonates >35 weeks of gestation. ELISA for NOS1 in umbilical cord blood was performed. Sources of NOS1 in umbilical cord were investigated by immunohistochemistry, western blot, ELISA, and quantitative PCR. Furthermore, umbilical cords of full-term neonates were subjected to 1% hypoxia ex vivo.

RESULTS

NOS1 was present in umbilical cord blood and increased in NE cases compared with controls. NOS1 was expressed in endothelial cells of the umbilical cord vein, but not in artery or blood cells. In ex vivo experiments, hypoxia was associated with increased levels of NOS1 in venous endothelial cells of the umbilical cord as well as in ex vivo culture medium.

CONCLUSION

This is the first study to investigate an early marker of NE. NOS1 is elevated with hypoxia, and further studies are needed to investigate it as a valuable tool for early diagnosis of neonatal brain injury.

Neonatal hypoxic ischemic encephalopathy-related biomarkers in serum and cerebrospinal fluid

Neonatal hypoxic ischemic encephalopathy (HIE) is a common disease caused by perinatal asphyxia, a major cause of neonatal death, neurological behavior, and long-term disability. Currently, the diagnosis and prognosis of neonatal HIE are based on nervous system clinical manifestations, imaging and electrophysiological examination. These take time and late diagnosis allows brain injury to occur in newborns, so that infants of many brain injury missed the best treatment time, left with varying degrees of neurological sequelae. The use of biomarkers to monitor brain injury and evaluate neuroprotective effects might allow the early intervention and treatment of neonatal HIE to reduce mortality rates. This study reviewed the mechanism of neonatal hypoxic ischemic encephalopathy in relation to numerous brain-related biomarkers including NSE, S-100β, GFAP, UCH-L1, Tau protein, miRNA, LDH, and CK-BB. In early diagnosis of neonatal HIE, S-100β and activin A seems to be better biomarkers. Biomarkers with the greatest potential to predict long-term neurologic handicap of neonates with HIE are GFAP and UCH-L1 and when combined with other markers or brain imaging can increase the detection rate of HIE. Tau protein is a unique biological component of nervous tissues, and might have value for neonatal HIE diagnosis. Combination of more than two biological markers should be a future research direction.

Comparative evaluation of risk factors, outcome and biomarker levels in young and old acute ischemic stroke patients

Background

Stroke is the third leading cause of death and disability worldwide accounting for 400-800 strokes per 100,000 individuals each year.

Purpose

In the present study, we compared risk factors, clinical outcome, and prognostic biomarkers NSE, S-100 ßß and ITIH4 levels in young and old acute ischemic stroke (AIS) patients.

Methods

We compared the risk factors and clinical outcomes in young (n = 38) and old (n = 66) AIS patients admitted to tertiary health care centre in Central India. In addition, we also evaluated NSE, S100ββ & ITIH4 levels in admission and discharge samples of young and old AIS patients with different clinical outcome.

Results

Hypertension was a major risk factor in 45% of young and 80% of old AIS patients. Hospital outcome was less favorable in young AIS patients with higher dependent rates of 24% as compared to 12% in old AIS patients. Whereas long term outcome at 12 and 18 months after discharge was more favorable in young AIS patients with low dependency rates of 16% and 11% as compared to 41% and 24% in older AIS patients respectively. Similarly, serum NSE, S100ββ and ITIH4 levels showed a distinct pattern of expression at discharge time in AIS patients with improved and dependent outcome in both the age groups.

Conclusion

Young males with hypertension and smoking habits are at a high risk of AIS while old AIS patients are at a greater risk of worse long term outcome. Serum levels of NSE and S100ββ are independent predictors of outcome in AIS patients. Similarly, it also suggests that serum ITIH4 levels could be used as a potential biomarker for predicting the outcome in AIS patients.

BRAIN HYPOTHERMIA THERAPY FOR NEONATAL HYPOXIC-ISCHEMIC ENCEPHALOPATHY WITH A SEVERELY ELEVATED SERUM CREATINE KINASE LEVEL

Several studies have shown that brain hypothermia therapy (BHT) after neonatal hypoxic-ischemic encephalopathy (HIE) can improve neurodevelopmental outcomes. However, there have been no reports of the neurodevelopmental outcomes for the infant with a serum creatine kinase (CK) level above 20,000 IU/L in association with neonatal HIE. We report a female infant with a very high serum CK level (26,428 IU/L) associated with neonatal asphyxia. We diagnosed this infant with moderate HIE, and BHT was achieved by head cooling within 6 hours after birth to an esophageal temperature of 34.5°C. There were no significant adverse events during BHT, and the CK level spontaneously decreased. Although we report only the short-term outcomes for this case, she presents neurodevelopmental delays at the age of 18 months. It may be correlated between high serum CK level and long-term neurodevelopmental delays.

Early predictors of outcome in infants treated with hypothermia for hypoxic-ischaemic encephalopathy

Hypoxic-ischaemic encephalopathy (HIE) is a leading cause of acquired neonatal brain injury. Assessment of the severity of cerebral injury and likely neurological outcome in infants with HIE is important for determining management and prognosis, for counselling parents, and for selection for neuroprotective trials. The condition of the infant at birth, the severity of HIE, neurophysiological tests, including amplitude-integrated electroencephalography (aEEG), biochemical markers, and neuroimaging have been used to assess prognosis and predict long-term outcome. The predictive accuracy of these indicators in the early postnatal period is modest. Neurophysiological assessment seems to be most helpful during the first 24 to 48 hours after birth whilst magnetic resonance imaging (MRI) seems most informative later. Several biochemical markers, including serum S100β and neuron-specific enolase (NSE), are also associated with HIE but their levels depend on the timing of sampling and their prognostic value is uncertain. Comprehensive neurophysiological assessment and neuroimaging may be limited to specialist centres. Therapeutic hypothermia is now standard care in infants with moderate to severe HIE so it is important to examine the influence of hypothermia on the assessment of prognosis in these infants.

Altered endothelial nitric oxide synthesis in preterm and small for gestational age infants

BACKGROUND

Preterm infants are often exposed to neuronal and endothelial damage. The aim of the present study was to investigate the correlation between endothelial dysfunction and neuronal injury in preterm infants.

METHODS

We compared serum nitric oxide (NO), endothelial nitric oxide synthase (eNOS) and neuron-specific enolase (NSE) concentrations in 33 moderate preterm (MP) and 47 late preterm (LP) infants using standard ELISA. Each group was classified as appropriate for gestational age (AGA) or small for gestational age (SGA).

RESULTS

Compared to the AGA infants, the SGA infants had higher NO on day 1 (MP: mean, 72.3 ng/mL, range, 50.9-99.5 ng/mL vs 52.2 ng/mL, range, 28.1-68.2 ng/mL, P < 0.05; LP: mean, 58.4 ng/mL, range, 25.7-66.4 ng/mL vs 43.7 ng/mL, range, 21.2-60.6 ng/mL, P < 0.05), lower eNOS concentration on day 3 in the MP group (mean, 5.8 IU/mL, range, 1.2-7.9 IU/mL vs 8.9 IU/mL, range, 4.2-14.6 IU/mL, P < 0.05), and on day 1 in the LP group (mean, 5.5 IU/mL, range, 1.5-8.1 IU/mL vs 7.7 IU/mL, range, 4.4-13.8 IU/mL, P < 0.05). The NO/eNOS ratio was higher in SGA infants compared with the AGA subgroups (MP: mean, 13.8, range, 9.9-20.2 vs mean, 9.9, range, 4.7-13.1, P < 0.05; LP: mean, 12.2, range, 9.2-19.9 vs mean, 9.9, range, 5.4-14.4, P < 0.05). AGA infants had lower NSE concentration compared with the SGA infants on day 1 in the LP group (mean, 27.4 ng/mL, range, 20-43 ng/mL vs mean, 40.89 ng/mL, range, 34-51 ng/mL, P < 0.05). A positive correlation was found between NO/eNOS ratio and NSE concentration (r = 0.75, P < 0.05 and r = 0.64, P < 0.05 on days 1 and 3, respectively).

CONCLUSION

High NO concentration in the context of low eNOS activity suggests a possible role of NO in the development of neuronal injury in SGA infants.

Calcium concentration in hypoxic-ischemic encephalopathy during hypothermia

BACKGROUND

The aim of this study was to investigate the relationship between prognosis and the changes in serum-ionized calcium concentration in neonates with hypoxic-ischemic encephalopathy (HIE) before and during brain hypothermia (BHT).

METHODS

Serum samples were obtained from 16 HIE neonates who underwent BHT. All patients underwent developmental testing at 18 months of age.

RESULTS

Mean serum-ionized calcium concentration in the poor outcome group (developmental quotient [DQ], <80; nine infants) was significantly lower than in the good outcome group (DQ >80; seven infants), both immediately before and after 6 h of BHT. Mean serum-ionized calcium concentration significantly decreased in both groups for 6 h, and the lowest adjusted serum-ionized calcium during 6 h of BHT was <1.05 mmol/L, known as the cut-off value for poor outcome, in 57.1% of the good outcome group.

CONCLUSION

The influx of calcium into cells continues regardless of neurological prognosis during the early phase of BHT, but BHT might protect some high-risk patients against neurological damage at low adjusted serum-ionized calcium concentration.

Elevated levels of serum sICAM-1 in asphyxiated low birth weight newborns

Perinatal hypoxia results in neuronal and endothelial cell damage. The main purpose of this study was to investigate the correlation of soluble intercellular adhesion molecule 1 (sICAM-1) expression and peripheral blood changes in perinatal asphyxia with neuronal injury markers in low birth weight (LBW) neonates. We compared the concentrations of serum sICAM-1, neuron-specific enolase (NSE) and antibodies specific for NR2 glutamate receptors in 29 asphyxiated and 20 control infants using standard enzyme immunoassay procedures. The mean total concentrations of sICAM-1 and neuron-specific proteins (NSE and NR2-specific antibodies) were higher in the asphyxiated infants than in the control infants. The serum sICAM-1 concentrations significantly correlated with Apgar scoring and with the pH and lactate data from capillary or arterial cord blood. No significant correlation between serum concentrations of neuron specific proteins and blood changes of asphyxia was found. Therefore, endothelial sICAM-1 expression levels might be accepted as an indicator of the severity of perinatal asphyxia in LBW infants.

Biomarkers S100B and neuron-specific enolase predict outcome in hypothermia-treated encephalopathic newborns*

OBJECTIVES

To evaluate if serum S100B protein and neuron-specific enolase measured during therapeutic hypothermia are predictive of neurodevelopmental outcome at 15 months in children with neonatal encephalopathy.

DESIGN

Prospective longitudinal cohort study.

SETTING

A level IV neonatal ICU in a freestanding children's hospital.

PATIENTS

Term newborns with moderate to severe neonatal encephalopathy referred for therapeutic hypothermia during the study period.

INTERVENTIONS

Serum neuron-specific enolase and S100B were measured at 0, 12, 24, and 72 hours of hypothermia.

MEASUREMENTS AND MAIN RESULTS

Of the 83 infants enrolled, 15 (18%) died in the newborn period. Survivors were evaluated by the Bayley Scales of Infant Development-II at 15 months. Outcomes were assessed in 49 of 68 survivors (72%) at a mean age of 15.2 ± 2.7 months. Neurodevelopmental outcome was classified by Bayley Scales of Infant Development-II Mental Developmental Index and Psychomotor Developmental Index scores, reflecting cognitive and motor outcomes, respectively. Four-level outcome classifications were defined a priori: normal = Mental Developmental Index/Psychomotor Developmental Index within 1 SD (> 85), mild = Mental Developmental Index/Psychomotor Developmental Index less than 1 SD (70-85), moderate/severe = Mental Developmental Index/Psychomotor Developmental Index less than 2 SD (< 70), or died. Elevated serum S100B and neuron-specific enolase levels measured during hypothermia were associated with increasing outcome severity after controlling for baseline and socioeconomic characteristics in ordinal regression models. Adjusted odds ratios for cognitive outcome were 2.5 (95% CI, 1.3-4.8) for S100B and 2.1 (95% CI, 1.2-3.6) for neuron-specific enolase, and for motor outcome, 2.6 (95% CI, 1.2-5.6) for S100B and 2.1 (95% CI, 1.2-3.6) for neuron-specific enolase.

CONCLUSIONS

Serum S100B and neuron-specific enolase levels in babies with neonatal encephalopathy are associated with neurodevelopmental outcome at 15 months. These putative biomarkers of brain injury may help direct care during therapeutic hypothermia.

Detecting brain injury in neonatal hypoxic ischemic encephalopathy: closing the gap between experimental and clinical research

Moderate to severe neonatal hypoxic ischemic encephalopathy remains an important cause of infant death and childhood disability. Early and accurate diagnosis of encephalopathy is difficult but critical for timely intervention. Thus, we have utilized a clinically relevant large animal model of asphyxia in-utero, followed by immediate lamb delivery, resuscitation and clinical care over the next 72h for assessment of potential biomarkers of brain injury. In-utero asphyxia was induced in twelve near-term lambs and outcomes compared with seven controls. Asphyxia resulted in bradycardia (97±12beats/min), hypotension (12.1±1mm Hg) and metabolic acidosis (pH6.9±0.02; base-excess -13.8±0.8mmol/l). 72h following asphyxia, cerebrospinal concentrations of malondialdehyde and S100B were elevated 2-fold and 5-fold, respectively, in asphyxic lambs compared to control lambs. Magnetic resonance spectroscopy (MRS) at 72h showed a significant decrease in n-acetyl aspartate: choline ratio in asphyxia lambs compared to that observed at 12h (0.56±0.23 vs. 0.82±0.15, respectively); lactate:choline ratio was not changed over this time. Marked neuropathology was observed in asphyxia lambs with neuronal degeneration in the hippocampus, thalamus, striatum and cortex. Astrogliosis was observed in the hippocampus and thalamus. Early blood markers of metabolic state showed limited predictive value of histological damage at 72h. MRS outcomes at 72h showed a modest but significant correlation with histological evidence of neuronal brain injury (lactate:N-acetyl aspartate ratio in the thalamus r(2)=0.2, p<0.01). MRS at 72h was best able to detect established brain injury, but a combination of biomarkers over multiple phases of injury may be able to assess the evolution of neonatal brain injury.

Single dose recombinant erythropoietin versus moderate hypothermia for neonatal hypoxic ischemic encephalopathy in low resource settings

OBJECTIVE

To determine the safety and efficacy of single dose systemic recombinant human erythropoietin (rEPO) in neonates with perinatal hypoxic Ischemic Encephalopathy (HIE), and its effect on serum brain-derived neurotrophic factor (BDNF) and neuron-specific enolase (NSE).

METHODS

Forty-five full-term neonates; 30 with perinatal HIE and 15 controls were studied. HIE neonates were randomized into three intervention groups (first 6 h of life): 10 received single subcutaneous 1500 U/kg rEPO at day-1, 10 subjected to hypothermia for 72 h and 10 received supportive care. BDNF and NSE measured during first 6 h and day 5 postnatal. Daily Thompson's score, MRI brain and neuromuscular function scale for survivors at 3 months of age were done.

RESULTS

Hypothermia group had best survival especially with stage-II Sarnat scale, followed by rEpo and supportive group. BDNF day-5 was significantly higher in each group compared to controls. MRI score and neuromuscular function score were non-significantly lower in the hypothermia group compared to rEPO.

CONCLUSIONS

Therapeutic hypothermia was superior to single dose rEpo for neuro-protection in HIE especially in patients with stage-II Sarnat scale. Therapeutic effect of combined rEPO multiple dosing and modest hypothermia therapy should be studied.

Serum biomarkers of MRI brain injury in neonatal hypoxic ischemic encephalopathy treated with whole-body hypothermia: a pilot study

OBJECTIVES

To determine if candidate biomarkers, ubiquitin carboxyl-terminal esterase L1 and glial fibrillary acidic protein, are elevated in neonates with hypoxic ischemic encephalopathy who die or have severe MRI injury compared with surviving infants with minimal or no injury on brain MRI.

DESIGN

Prospective observational study.

SETTING

Level IIIC outborn neonatal ICU in a free-standing children's hospital.

PATIENTS

Term newborns with moderate-to-severe hypoxic ischemic encephalopathy referred for therapeutic hypothermia

INTERVENTIONS

Serum specimens were collected at 0, 12, 24, and 72 hours of cooling. MRI was performed in surviving infants at target 7-10 days of life and was scored by a pediatric neuroradiologist masked to biomarker and clinical data.

MEASUREMENTS AND MAIN RESULTS

Serial biomarker levels were determined in 20 hypoxic ischemic encephalopathy patients. Ubiquitin carboxyl-terminal esterase L1 was higher at initiation and 72 hours of cooling, while glial fibrillary acidic protein was higher at 24 and 72 hours in babies with adverse outcome compared with those with favorable outcome.

CONCLUSIONS

This preliminary data support further studies to evaluate ubiquitin carboxyl-terminal esterase L1 and glial fibrillary acidic protein as immediate biomarkers of cerebral injury severity in newborns with hypoxic ischemic encephalopathy.

The metabolomic profile of umbilical cord blood in neonatal hypoxic ischaemic encephalopathy

Background

Hypoxic ischaemic encephalopathy (HIE) in newborns can cause significant long-term neurological disability. The insult is a complex injury characterised by energy failure and disruption of cellular homeostasis, leading to mitochondrial damage. The importance of individual metabolic pathways, and their interaction in the disease process is not fully understood. The aim of this study was to describe and quantify the metabolomic profile of umbilical cord blood samples in a carefully defined population of full-term infants with HIE.

Methods and Findings

The injury severity was defined using both the modified Sarnat score and continuous multichannel electroencephalogram. Using these classification systems, our population was divided into those with confirmed HIE (n = 31), asphyxiated infants without encephalopathy (n = 40) and matched controls (n = 71). All had umbilical cord blood drawn and biobanked at −80°C within 3 hours of delivery. A combined direct injection and LC-MS/MS assay (AbsolutIDQ p180 kit, Biocrates Life Sciences AG, Innsbruck, Austria) was used for the metabolomic analyses of the samples. Targeted metabolomic analysis showed a significant alteration between study groups in 29 metabolites from 3 distinct classes (Amino Acids, Acylcarnitines, and Glycerophospholipids). 9 of these metabolites were only significantly altered between neonates with Hypoxic ischaemic encephalopathy and matched controls, while 14 were significantly altered in both study groups. Multivariate Discriminant Analysis models developed showed clear multifactorial metabolite associations with both asphyxia and HIE. A logistic regression model using 5 metabolites clearly delineates severity of asphyxia and classifies HIE infants with AUC = 0.92. These data describe wide-spread disruption to not only energy pathways, but also nitrogen and lipid metabolism in both asphyxia and HIE.

Conclusion

This study shows that a multi-platform targeted approach to metabolomic analyses using accurately phenotyped and meticulously biobanked samples provides insight into the pathogenesis of perinatal asphyxia. It highlights the potential for metabolomic technology to develop a diagnostic test for HIE.

Biomarkers of brain injury in neonatal encephalopathy treated with hypothermia

OBJECTIVE

To determine if early serum S100B and neuron-specific enolase (NSE) levels are associated with neuroradiographic and clinical evidence of brain injury in newborns with encephalopathy.

STUDY DESIGN

Patients who received therapeutic whole-body hypothermia were prospectively enrolled in this observational study. Serum specimens were collected at 0, 12, 24, and 72 hours of cooling. S100B and NSE levels were measured by enzyme linked immunosorbent assay. Magnetic resonance imaging was performed in surviving infants at 7-10 days of life. Standardized neurologic examination was performed by a child neurologist at 14 days of life. Multiple linear regression analyses were performed to evaluate the association between S100B and NSE levels and unfavorable outcome (death or severe magnetic resonance imaging injury/significant neurologic deficit). Cutoff values were determined by receiver operating curve analysis.

RESULTS

Newborns with moderate to severe encephalopathy were enrolled (n = 75). Median pH at presentation was 6.9 (range, 6.5-7.35), and median Apgar scores of 1 at 1 minute, 3 at 5 minutes, and 5 at 10 minutes. NSE and S100B levels were higher in patients with unfavorable outcomes across all time points. These results remained statistically significant after controlling for covariables, including encephalopathy grade at presentation, Apgar score at 5 minutes of life, initial pH, and clinical seizures.

CONCLUSION

Elevated serum S100B and NSE levels measured during hypothermia were associated with neuroradiographic and clinical evidence of brain injury in encephalopathic newborns. These brain-specific proteins may be useful immediate biomarkers of cerebral injury severity.

Obstetric parameters and Doppler findings in cerebral circulation as predictors of 1 year neurodevelopmental outcome in asphyxiated infants

OBJECTIVE

To establish the association of cardiotocography (CTG) and other obstetric parameters with pulsed Doppler findings in cerebral arteries during the first day of life, and to compare the cerebral artery Doppler with other determinants of asphyxia in predicting 1-year neurological outcome in asphyxiated full-term infants.

STUDY DESIGN

Cerebral blood flow velocity (CBFV) were measured from the anterior cerebral (ACA) and basilar (BA) arteries in 30 asphyxiated and 30 healthy-term infants using pulsed Doppler ultrasonography at approximately 24 h of age. CTG, cord artery pH, Apgar scores, biochemical asphyxia markers and symptoms of hypoxic-ischemic encephalopathy (HIE) were compared with the Doppler findings in respect of the ability to predict the outcome, defined by death or impaired neurological performance at 1 year of age.

RESULT

In all, 20% of the asphyxiated infants but none in the control group had increased peak systolic CBFVs (mean+3 s.d.) in the ACA or BA. The sensitivity of increased systolic CBFV to predict abnormal outcome in the asphyxia group was 83%, specificity 95% and the sensitivity of the combination of HIE grade from 2 to 3 and increased systolic CBFV in the ACA or BA was 100% and specificity was 95%, respectively. Pathological CTG and low cord artery pH or low Apgar scores showed low predictive power.

CONCLUSION

Grade from 2 to 3 HIE and the systolic CBFV (mean+3 s.d.) in the ACA or BA by Doppler ultrasound seemed to predict the outcome in asphyxiated infants at 1 year of age better than CTG, acid basement status, Apgar scores or asphyxia markers. If an increase of more than +3 s.d. in the systolic CBFV does not occur within the first 24 h of life, a good 1-year neurological outcome may be anticipated.

S100B - a potential biomarker for early detection of neonatal brain damage following asphyxia

Birth asphyxia results in a significant percentage of neonatal morbidity and mortality. A key factor in the management of this complication is the early and accurate detection of brain damage following asphyxia. Currently, reliable tools for such diagnosis are absent. Extensive research has focused on biomarkers in an attempt to solve this matter. Recent data marked serum and urine elevation of the S100B protein as an established peripheral biomarker for detection of brain injury including traumatic head injuries and brain damage following cardiac arrest and stroke. In the past decade, a substantial number of studies illustrated the potential use of S100B testing in order to detect brain damage in asphyxiated newborns. This review summarizes the available data regarding the use of S100B as a biomarker of brain damage following birth asphyxia.

Potential biomarkers for hypoxic-ischemic encephalopathy

Cerebral hypothermia reduces brain injury and improves behavioral recovery after hypoxia-ischemia (HI) at birth. However, using current enrolment criteria many infants are not helped, and conversely, a significant proportion of control infants survive without disability. In order to further improve treatment we need better biomarkers of injury. A 'true' biomarker for the phase of evolving, 'treatable' injury would allow us to identify not only whether infants are at risk of damage, but also whether they are still able to benefit from intervention. Even a less specific measure that allowed either more precise early identification of infants at risk of adverse neurodevelopmental outcome would reduce the variance of outcome of trials, improving trial power while reducing the number of infants unnecessarily treated. Finally, valid short-term surrogates for long term outcome after treatment would allow more rapid completion of preliminary evaluation and thus allow new strategies to be tested more rapidly. Experimental studies have demonstrated that there is a relatively limited 'window of opportunity' for effective treatment (up to about 6-8h after HI, the 'latent phase'), before secondary cell death begins. We critically evaluate the utility of proposed biochemical, electronic monitoring, and imaging biomarkers against this framework. This review highlights the two central limitations of most presently available biomarkers: that they are most precise for infants with severe injury who are already easily identified, and that their correlation is strongest at times well after the latent phase, when injury is no longer 'treatable'. This is an important area for further research.

Actualities on molecular pathogenesis and repairing processes of cerebral damage in perinatal hypoxic-ischemic encephalopathy

Hypoxic-ischemic encephalopathy (HIE) is the most important cause of cerebral damage and long-term neurological sequelae in the perinatal period both in term and preterm infant.

Hypoxic-ischemic (H-I) injuries develop in two phases: the ischemic phase, dominated by necrotic processes, and the reperfusion phase, dominated by apoptotic processes extending beyond ischemic areas. Due to selective ischemic vulnerability, cerebral damage affects gray matter in term newborns and white matter in preterm newborns with the typical neuropathological aspects of laminar cortical necrosis in the former and periventricular leukomalacia in the latter.

This article summarises the principal physiopathological and biochemical processes leading to necrosis and/or apoptosis of neuronal and glial cells and reports recent insights into some endogenous and exogenous cellular and molecular mechanisms aimed at repairing H-I cerebral damage.

Maternal allopurinol during fetal hypoxia lowers cord blood levels of the brain injury marker S-100B

BACKGROUND

Fetal hypoxia is an important determinant of neonatal encephalopathy caused by birth asphyxia, in which hypoxia-induced free radical formation plays an important role.

HYPOTHESIS

Maternal treatment with allopurinol, will cross the placenta during fetal hypoxia (primary outcome) and reduce S-100B and free radical formation (secondary outcome).

METHODS

In a randomized, double-blind feasibility study, 53 pregnant women in labor (54 fetuses) with a gestational age of >36 weeks and fetal hypoxia, as indicated by abnormal/nonreassuring fetal heart rate tracing or fetal scalp pH of <7.20, received 500 mg of allopurinol or placebo intravenously. Severity of fetal hypoxia, brain damage and free radical formation were assessed by arterial cord blood lactate, S-100B and non-protein-bound-iron concentrations, respectively. At birth, maternal and cord blood concentrations of allopurinol and its active metabolite oxypurinol were determined.

RESULTS

Allopurinol and oxypurinol concentrations were within the therapeutic range in the mother (allopurinol > 2 mg/L and/or oxypurinol > 4 mg/L) but not always in arterial cord blood. We therefore created 3 groups: a placebo (n = 27), therapeutic allopurinol (n = 15), and subtherapeutic allopurinol group (n = 12). Cord lactate concentration did not differ, but S-100B was significantly lower in the therapeutic allopurinol group compared with the placebo and subtherapeutic allopurinol groups (P < .01). Fewer therapeutic allopurinol cord samples had measurable non-protein-bound iron concentrations compared with placebo (P < .01).

CONCLUSIONS

Maternal allopurinol/oxypurinol crosses the placenta during fetal hypoxia. In fetuses/newborns with therapeutic allopurinol/oxypurinol concentrations in cord blood, lower plasma levels of the brain injury marker protein S-100B were detected. A larger allopurinol trial in compromised fetuses at term seems warranted. The allopurinol dosage must be adjusted to achieve therapeutic fetal allopurinol/oxypurinol concentrations.

Neuron-specific enolase and S-100B are associated with neurologic outcome after pediatric cardiac arrest

OBJECTIVE

To characterize the pattern of serum biochemical markers of central nervous system injury (neuron-specific enolase [NSE], S-100B, plasminogen activator inhibitor-1 [PAI-1]) after pediatric cardiac arrest and determine whether there is an association between biomarker concentrations and neurologic outcome.

DESIGN

Prospective, observational study.

SETTING

Urban, tertiary care children's hospital.

PATIENTS

Cardiac arrest survivors, n = 35.

INTERVENTIONS

Serial blood sampling, pediatric cerebral performance category, and standardized neurologic examination.

MEASUREMENTS AND MAIN RESULTS

Serial serum NSE and S-100B concentrations over 96 hrs and PAI-1 at 24 hrs were measured in children (age <18 yrs) who had return of spontaneous circulation following cardiac arrest. Neurologic outcome was prospectively categorized as poor if the change in pre- to postarrest pediatric cerebral performance category was > or =2. Biomarker concentrations were compared between outcome groups and between survival groups using longitudinal analysis correcting for multiple comparisons. Median levels (25th, 75th percentiles) are reported. Receiver operating characteristic analyses were performed at all time points. Biomarker concentrations showed statistically significant differences. Of the 35 patients, neurologic outcomes were poor in 19, with 15 deaths. Median NSE concentrations differed by outcome when measured at > or =48 hrs, and by survival at > or =24 hrs. S-100B concentrations were not significantly associated with neurologic outcome. S-100B levels were associated with survival outcome at > or =48 hrs. PAI-1 levels were not significantly associated with either neurologic or survival outcomes.

CONCLUSIONS

The timing, intensity, and duration of serum NSE and S-100B biomarker concentration patterns are associated with neurologic and survival outcomes following pediatric cardiac arrest. Serum NSE concentrations at > or =48 hrs are associated with neurologic outcome, whereas serum S-100B levels at > or =48 hrs are associated with survival. Prospective analysis of these markers may help to predict outcomes and guide postresuscitative therapies.

Systematic review of biomarkers of brain injury in term neonatal encephalopathy

Although neonatal hypoxic-ischemic encephalopathy is a common cause of childhood developmental disability, its timing, duration, and outcomes are poorly defined. Biomarkers serve as surrogates for disease injury, evolution, and outcome, but no tissue biomarker in routine clinical use can help predict outcomes in term newborn encephalopathy. We reviewed biomarkers in human term neonatal encephalopathy, to determine if current biomarkers are strong enough for clinical use as predictors of outcomes. A comprehensive search of databases identified 110 publications that met our inclusion criteria, i.e., (1) newborns at >36 weeks; (2) neonatal encephalopathy as defined by the American College of Obstetrics and Gynecology; (3) the use of a serum, urine, or cerebrospinal fluid biomarker; and (4) reported outcomes beyond age 12 months. Of those 110 publications, 22 reported outcomes beyond age 12 months. In single reports, urine lactate (P < 0.001), first urine S100 (P < 0.0001), cord-blood interleukin-6 (P = 0.02), serum nonprotein-bound iron (P < 0.001), serum CD14 cell NFkappaB activation (P = 0.014), serum interleukin-8 (P = 0.03), and serum ionized calcium (P = 0.001) were potential predictors of death or abnormal outcomes. A meta-analysis identified serum interleukin-1b (P = 0.04, n = 3), serum interleukin-6 (P = 0.04, n = 2), cerebrospinal fluid neuron-specific enolase (P = 0.03, n = 3), and cerebrospinal fluid interleukin-1b (P = 0.003, n = 2) as putative predictors of abnormal outcomes in survivors, when measured before age 96 hours. Several serum, urine, and cerebrospinal fluid biomarkers of term neonatal encephalopathy may provide important information regarding long-term outcomes. None, however, were studied extensively enough to warrant routine clinical use. Validation of these markers, either alone or in combination, is required in the development of viable therapeutic interventions.

The chilling details: hypoxic-ischemic encephalopathy

Hypoxic-ischemic encephalopathy (HIE) is one of the most important complications found in the newborn period. It is the result of a deprivation of oxygen and glucose to the neural tissue, which may be the result of either hypoxemia or ischemia. Experimental animal research and clinical observations in humans have noted that the pattern of injury occurs in 2 phases. The first phase is a primary energy failure related to the insult, and then a second energy failure occurs some hours later. The combined effects of cellular energy failure, acidosis, glutamate release, intracellular accumulation of calcium, lipid peroxidation, and nitric oxide neurotoxicity destroy essential components of the cell, culminating in cell death. The clinical presentation depends on the severity, timing, and duration of the insult, with symptoms typically evolving over approximately 72 hours. Hypothermia strategies are aimed at targeting this narrow window of opportunity to ameliorate the brain injury.

Kinetics of serum S100B in newborns with intracranial lesions

BACKGROUND

The purpose of the present study was to evaluate the usefulness of serum S100B as a clinical marker of intracranial lesions in newborns.

METHODS

The study involved 22 normal and 40 diseased newborns. Serum S100B level was measured on days 1 and 6 in normal newborns. Diseased newborns were classified into four groups: birth asphyxia with hypoxic-ischemic encephalopathy (HIE); birth asphyxia without HIE; intracranial hemorrhage (mainly subarachnoid); and brain malformation. In each group the serum S100B level was measured on days 1, 2 and 6. Development was also assessed to investigate the relation between serum S100B level and prognosis at 18 months after birth.

RESULTS

In normal newborns, serum S100B level was significantly higher in those with liquor to meconium stain than in those without. In diseased newborns, serum S100B level on day 1 was significantly higher in the HIE group than in all other groups (P < 0.05). There was no significant difference in serum S100B level between control and intracranial hemorrhage, or brain malformation. In newborns with birth asphyxia, serum S100B level was significantly higher in severe birth asphyxia than in mild or moderate birth asphyxia; two newborns with serum S100B level > or =10 microg/L on days 1 and 2 developed cerebral palsy, others with no increase of S100B were all developing normally.

CONCLUSIONS

Serum S100B level is a useful marker of acute perinatal brain damage, and is particularly valuable for fetal distress. In newborns with birth asphyxia, serum S100B levels serve as a biochemical marker of HIE.

S100B modulates IL-6 release and cytotoxicity from hypothermic brain cells and inhibits hypothermia-induced axonal outgrowth

Brain protection is essential during neonatal and pediatric cardiac surgery. Deep hypothermia is still the most important method for achieving neuroprotection during cardiopulmonary bypass. Previously, we could demonstrate that deep hypothermia induces substantial cytotoxicity in brain cells as well as increased release of the pro-inflammatory cytokine interleukin-6 (IL-6), which plays an important role in neuroprotection and neuroregeneration. Deep hypothermia is also associated with increased levels of the astrocytic protein S100B in the serum and cerebrospinal fluid of patients. Since S100B may modulate pro-inflammatory cytokines and may stimulate neurite outgrowth, we have tested the hypothesis that nanomolar concentrations of S100B may increase IL-6 release from brain cells and support axonal outgrowth from organotypic brain slices under hypothermic conditions. S100B administration substantially reduced neuronal and glial cytotoxicity under hypothermic conditions. In the presence of S100B hypothermia-induced IL-6 release in primary astrocytes was significantly increased but reduced in BV-2 microglial cells and primary neurons. Surprisingly, deep hypothermia increased axonal outgrowth from brain slices and--in contrast to our hypothesis--this hypothermia-induced neurite outgrowth was inhibited by S100B. These data suggest that S100B differentially influences cytokine release and cytotoxicity from distinct brain cells and may inhibit neuroregeneration by suppressing hypothermia-induced axonal outgrowth.

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.

Correlation of neuron-specific enolase and S100B with histological cerebral damage in fetal sheep after severe asphyxia

Experimental brain damage was induced in 16 fetal sheep by umbilical cord occlusion, and the correlation of neuron-specific enolase (NSE) or S100B with the damage grade was investigated in seven fetuses. Significant correlations of damage degree with NSE (p = 0.016) and S100B (p = 0.018) in serum 2 h after insult were shown by Spearman's test. These findings suggest that they represent potentially useful markers for detecting brain damage at early stage after ischemic insult.