Neuron-specific enolase as a marker of the severity and outcome of hypoxic ischemic encephalopathy

Key Inflammatory Biomarkers in Perinatal Asphyxia: A Comprehensive Review

This article summarizes the current evidence regarding inflammatory biomarkers (placental and postnatal) and provides a comprehensive understanding of their roles: (1) diagnostic accuracy to predict the severity of hypoxic-ischemia encephalopathy (HIE), (2) value in assessing treatment responses, and (3) prediction of both short- and long-term neurodevelopmental outcomes. In the early critical stages of perinatal asphyxia, inflammatory biomarkers may guide clinical decision-making. Additional research is required to increase our understanding of the optimal utility of biomarkers to predict the severity, evolution, and developmental outcomes after exposure to HIE.

Significant correlation between serum biomarkers and outcome in neonatal hypoxic-ischaemic encephalopathy

AIM

Associations between serum biomarkers S100 calcium-binding protein B (S100B) and neuron-specific enolase (NSE) in neonates with hypoxic-ischaemic encephalopathy (HIE) offer contradicting data in regard to neurocognitive outcome. The aim of our study was to provide another dataset to answer this question if S100B or NSE correlates to outcome in neonatal HIE. In addition, we investigate whether amplitude-integrated EEG (aEEG) or magnetic resonance imaging (MRI) also has predictive value.

METHODS

In neonates with HIE born in Vorarlberg, Austria, (n = 34) from 2012to 2020, NSE and S100B serum levels were measured on day one. aEEG was installed at admission and MRI performed within 7 days. Surviving children (n = 27) were categorised as good or poor outcome by using an age-appropriate neurocognitive test and a standardised neurological follow-up. Positive and negative predictive values and receiver operating characteristic curves were calculated to evaluate the prognostic value.

RESULTS

S100B showed best positive and negative predictive value, 72.7% and 90.5%, respectively, and a significant area under the curve of 0.820. NSE showed a positive and a negative predictive value of 43.8% and 81.3% and an area under the curve of 0.757. Severely abnormal aEEG and abnormal MRI significantly correlated with outcome (p = 0.024 and 0.001 respectively).

CONCLUSION

S100B and NSE on day one, severely abnormal aEEG and abnormal MRI show a significant correlation and good predictive value for neurocognitive outcome.

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.

Newborns with Favourable Outcomes after Perinatal Asphyxia Have Upregulated Glucose Metabolism-Related Proteins in Plasma

Hypoxic-ischaemic encephalopathy (HIE) is an important cause of morbidity and mortality globally. Although mild therapeutic hypothermia (TH) may improve outcomes in selected babies, the mechanism of action is not fully understood. A proteomics discovery study was carried out to analyse proteins in the plasma of newborns with HIE. Proteomic analysis of plasma from 22 newborns with moderate-severe HIE that had initially undergone TH, and relative controls including 10 newborns with mild HIE who did not warrant TH and also cord blood from 10 normal births (non-HIE) were carried out using the isobaric Tandem Mass Tag (TMT®) 10plexTM labelling with tandem mass spectrometry. A total of 7818 unique peptides were identified in all TMT10plexTM samples, translating to 3457 peptides representing 405 proteins, after applying stringent filter criteria. Apart from the unique protein signature from normal cord blood, unsupervised analysis revealed several significantly regulated proteins in the TH-treated moderate-severe HIE group. GO annotation and functional clustering revealed various proteins associated with glucose metabolism: the enzymes fructose-bisphosphate aldolase A, glyceraldehyde-3-phosphate dehydrogenase, phosphoglycerate mutase 1, phosphoglycerate kinase 1, and pyruvate kinase PKM were upregulated in newborns with favourable (sHIE+) outcomes compared to newborns with unfavourable (sHIE-) outcomes. Those with favourable outcomes had normal MR imaging or mild abnormalities not predictive of adverse outcomes. However, in comparison to mild HIE and the sHIE- groups, the sHIE+ group had the additional glucose metabolism-related enzymes upregulated, including triosephosphate isomerase, α-enolase, 6-phosphogluconate dehydrogenase, transaldolase, and mitochondrial glutathione reductase. In conclusion, our plasma proteomic study demonstrates that TH-treated newborns with favourable outcomes have an upregulation in glucose metabolism. These findings may open new avenues for more effective neuroprotective therapy.

Brain Damage in Preterm and Full-Term Neonates: Serum Biomarkers for the Early Diagnosis and Intervention

The Brain is vulnerable to numerous insults that can act in the pre-, peri-, and post-natal period. There is growing evidence that demonstrate how oxidative stress (OS) could represent the final common pathway of all these insults. Fetuses and newborns are particularly vulnerable to OS due to their inability to active the antioxidant defenses. Specific molecules involved in OS could be measured in biologic fluids as early biomarkers of neonatal brain injury with an essential role in neuroprotection. Although S-100B seems to be the most studied biomarker, its use in clinical practice is limited by the complexity of brain damage etiopathogenesis and the time of blood sampling in relation to the brain injury. Reliable early specific serum markers are currently lacking in clinical practice. It is essential to determine if there are specific biomarkers that can help caregivers to monitor the progression of the disease in order to active an early neuroprotective strategy. We aimed to describe, in an educational review, the actual evidence on serum biomarkers for the early identification of newborns at a high risk of neurological diseases. To move the biomarkers from the bench to the bedside, the assays must be not only be of a high sensitivity but suitable for the very rapid processing and return of the results for the clinical practice to act on. For the best prognosis, more studies should focus on the association of these biomarkers to the type and severity of perinatal brain damage.

[Results of a multicenter observational program to evaluate the effectiveness of complex therapy of patients with chronic cerebrovascular pathology with cognitive impairment with Cortexin and Neuromexol (CORNELia study)]

OBJECTIVE

To evaluate the effectiveness of complex therapy with Cortexin and Neuromexol in patients with chronic cerebral ischemia (CCI) and cognitive impairment (CI).

MATERIAL AND METHODS

We examined 801 patients with CCI on the background of arterial hypertension and atherosclerosis with confirmed CI: 329 (41.1%) men and 472 (58.9%) women aged 30 to 80 years (mean age 64±10 years), who were examined. Cortexin and Neuromexol. Examination - Mini-Mental State Examination (MMSE) scale, hour-long drawing test (HDT) and severity of depressive states (Brief Geriatric Depression Scale, Mini Geriatric Depression Scal, MGDS). In 30 patients receiving Cortexin and Neuromexol (main group, MG) and 30 patients in the comparison group (CG), biomarkers of ischemic brain damage (NSE, antibodies to NR2, VEGFA) were determined. The examination was carried out before the start of treatment and after 30 days.

RESULTS

During therapy with Cortexin and Neuromexol, characteristic signs of a decrease in the severity of CI were noted (p<0.05). A positive correlation was revealed between the performance indicators of the MMSE and TFC tests, both before and after treatment (r=0.5 and r=0.6, respectively; p<0.05). A positive effect of therapy on the emotional background of patients was noted, in particular, a decrease in the severity of depressive symptoms on the MGDS scale. During therapy, a 2-fold decrease in the NSE level (p<0.05) was detected in the MG, which indicates a decrease in the structural and functional parameters of biomembrane neurons in the brain. The concentration of antibodies to NR2 decreased compared to the baseline level in both groups (p<0.05), and VEGFA decreased only in the MG (p<0.05).

CONCLUSION

The results of the study allow us to recommend the complex prescription of Cortexin 10 mg/day for 10 days and Neuromexol tablets 125 mg (375-750 mg/day) for 30 days for chronic CVD. Complex therapy with Cortexin and Neuromexol is effective and safe in patients with CCI and CI.

Two Useful Umbilical Biomarkers for Therapeutic Hypothermia Decision in Patients with Hypoxic İschemic Encephalopathy with Perinatal Asphyxia: Netrin-1 and Neuron Specific Enolase

Hypoxic-ischemic encephalopathy (HIE) has a high risk of mortality in addition to serious neurological damage. In this study, we investigated the values of umbilical cord netrin-1 (NT-1) and neuron specific enolase (NSE) levels in the early diagnosis of HIE stage II/III induced by neonatal asphyxia. In the study group, infants with gestational age ≥ 36 weeks who were diagnosed with HIE II/III were included. NT-1 and NSE levels were measured from the umbilical cord immediately after birth. Results were compared between HIE II/III and the healthy control group. Cutoff values for serum NT-1 and NSE were determined with receiver-operating characteristics curves and the area under the curve (AUC) was used to determine the diagnostic value of NT-1 and NSE levels in infants diagnosed with HIE II/III. NT-1 (358.3 ± 108.3 pg/mL) and NSE (52.97 ± 17.8 ng/mL) levels in the cord blood in the HIE group were significantly higher (p = .030, p = .001, respectively) than cord blood values in the control group (NT-1 (275.1 ± 84.6 pg/mL) and NSE (28.7 ± 16.3 ng/mL)). NT-1 cutoff value for HIE was 292.3 pg/mL and 34.7 ng/mL for NSE (AUC: 990, sensitivity: 94%, specificity 100% and AUC: 1.0, sensitivity: 100% vs. specificity 100%, respectively). NT-1 and NSE represent candidate biomarkers with high reliability in the prediction in newborns with moderate-to-severe HIE.

The Usefulness of Serum Brain Damage Biomarkers in Detection and Evaluation of Hypoxic Ischemic Encephalopathy in Calves with Perinatal Asphyxia

The purpose of the present study was to determine hypoxic brain damage in calves with perinatal asphyxia using brain-specific damage biomarkers. Ten healthy and 25 calves with perinatal asphyxia were enrolled in the study. Clinical examination, neurological status score, and laboratory analysis were performed at admission, 24, 48, and 72 h. Serum concentrations of ubiquitin carboxy-terminal hydrolysis 1 (UCHL1), calcium-binding protein B (S100B), adrenomodullin (ADM), activitin A (ACTA), neuron-specific enolase (NSE), glial fibrillary acidic protein (GFAP) and creatine kinase-brain (CK-B) were measured. Histopathological and immunohistochemical examinations of the brain tissue were performed in 13 nonsurvivor calves. The neurological status score of the calves with asphyxia was significantly (p < 0.05) lower. Mix metabolic-respiratory acidosis and hypoxemia were detected in calves with asphyxia. Serum UCHL1 and S100B were significantly (p < 0.05) increased, and NSE, ACTA, ADM, and CK-B were decreased (p < 0.05) in calves with asphyxia. Histopathological and immunohistochemical examinations confirmed the development of mild to severe hypoxic-ischemic encephalopathy. In conclusion, asphyxia and hypoxemia caused hypoxic-ischemic encephalopathy in perinatal calves. UCHL1 and S100B concentrations were found to be useful markers for the determination of hypoxic-ischemic encephalopathy in calves with perinatal asphyxia. Neurological status scores and some blood gas parameters were helpful in mortality prediction.

Diagnostic and Therapeutic Roles of the “Omics” in Hypoxic–Ischemic Encephalopathy in Neonates

Perinatal asphyxia and neonatal encephalopathy remain major causes of neonatal mortality, despite the improved availability of diagnostic and therapeutic tools, contributing to neurological and intellectual disabilities worldwide. An approach using a combination of clinical data, neuroimaging, and biochemical parameters is the current strategy towards the improved diagnosis and prognosis of the outcome in neonatal hypoxic–ischemic encephalopathy (HIE) using bioengineering methods. Traditional biomarkers are of little use in this multifactorial and variable phenotype-presenting clinical condition. Novel systems of biology-based “omics” approaches (genomics, transcriptome proteomics, and metabolomics) may help to identify biomarkers associated with brain and other tissue injuries, predicting the disease severity in HIE. Biomarker studies using omics technologies will likely be a key feature of future neuroprotective treatment methods and will help to assess the successful treatment and long-term efficacy of the intervention. This article reviews the roles of different omics as biomarkers of HIE and outlines the existing knowledge of our current understanding of the clinical use of different omics molecules as novel neonatal brain injury biomarkers, which may lead to improved interventions related to the diagnostic and therapeutic aspects of HIE.

Serum neuron-specific enolase, magnetic resonance imaging, and electrophysiology for predicting neurodevelopmental outcomes of neonates with hypoxic-ischemic encephalopathy: a prospective study

Background

Neonatal hypoxic-ischemic encephalopathy (HIE) is an important cause of mortality and morbidity. Effective indicators for the early diagnosis of brain injury after HIE and prognosis are lacking. This study aimed to examine the predictive value of serum neuron-specific enolase (NSE), amplitude-integrated electroencephalography (aEEG), and magnetic resonance imaging (MRI), alone and in combination, for the neurological outcomes in neonates with HIE.

Methods

Newborns with HIE born and treated at the Third Affiliated Hospital of An-Hui Medical University were consecutively included in this prospective cohort study (June 2013 to December 2020). Encephalopathy was classified as mild, moderate or severe according to Samat and Sarnat. All patients were assessed serum 1-day NSE and 3-day NSE levels after birth. The children were classified by neurological examination and Bayley Scales of Infant Development II at 18 months of age. ROC analysis was used to evaluate the predictive accuracy of the neurodevelopment outcomes.

Results

A total of 50 HIE neonates were enrolled (normal group: 32 (64.0%), moderate delay: 5 (10.0%), severe delay: 30(26.0%)) according to Bayley II scores. Serum 3-day NSE levels increased with worsening neurodevelopment outcomes (normal: 20.52 ± 6.42 μg/L vs. moderate: 39.82 ± 5.92 μg/L vs. severe: 44.60 ± 9.01 μg/L, P < 0.001). The MRI findings at 4–7 days after birth were significantly different among the three groups (P < 0.001). Forty-two (84.0%) children had abnormal aEEG. The combination of the three abnormalities combined together had 100% sensitivity, 97.70% specificity, 98.25% PPV, and 99.98% NPV.

Conclusions

MRI, aEEG, and 3-day NSE can predict the neurological prognosis of newborns with HIE without hypothermia treatment. Their combination can improve the predictive ability for long-term neurobehavioral prognosis.

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.

Serial blood cytokine and chemokine mRNA and microRNA over 48 h are insult specific in a piglet model of inflammation-sensitized hypoxia-ischaemia

BACKGROUND

Exposure to inflammation exacerbates injury in neonatal encephalopathy (NE). We hypothesized that brain biomarker mRNA, cytokine mRNA and microRNA differentiate inflammation (E. coli LPS), hypoxia (Hypoxia), and inflammation-sensitized hypoxia (LPS+Hypoxia) in an NE piglet model.

METHODS

Sixteen piglets were randomized: (i) LPS 2 μg/kg bolus; 1 μg/kg infusion (LPS; n = 5), (ii) Saline with hypoxia (Hypoxia; n = 6), (iii) LPS commencing 4 h pre-hypoxia (LPS+Hypoxia; n = 5). Total RNA was acquired at baseline, 4 h after LPS and 1, 3, 6, 12, 24, 48 h post-insult (animals euthanized at 48 h). Quantitative PCR was performed for cytokines (IL1A, IL6, CXCL8, IL10, TNFA) and brain biomarkers (ENO2, UCHL1, S100B, GFAP, CRP, BDNF, MAPT). MicroRNA was detected using GeneChip (Affymetrix) microarrays. Fold changes from baseline were compared between groups and correlated with cell death (TUNEL) at 48 h.

RESULTS

Within 6 h post-insult, we observed increased IL1A, CXCL8, CCL2 and ENO2 mRNA in LPS+Hypoxia and LPS compared to Hypoxia. IL10 mRNA differentiated all groups. Four microRNAs differentiated LPS+Hypoxia and Hypoxia: hsa-miR-23a, 27a, 31-5p, 193-5p. Cell death correlated with TNFA (R = 0.69; p < 0.01) at 1-3 h and ENO2 (R = -0.69; p = 0.01) at 48 h.

CONCLUSIONS

mRNA and miRNA differentiated hypoxia from inflammation-sensitized hypoxia within 6 h in a piglet model. This information may inform human studies to enable triage for tailored neuroprotection in NE.

IMPACT

Early stratification of infants with neonatal encephalopathy is key to providing tailored neuroprotection. IL1A, CXCL8, IL10, CCL2 and NSE mRNA are promising biomarkers of inflammation-sensitized hypoxia. IL10 mRNA levels differentiated all three pathological states; fold changes from baseline was the highest in LPS+Hypoxia animals, followed by LPS and Hypoxia at 6 h. miR-23, -27, -31-5p and -193-5p were significantly upregulated within 6 h of a hypoxia insult. Functional analysis highlighted the diverse roles of miRNA in cellular processes.

Cerebrospinal fluid findings and hypernatremia in COVID-19 patients with altered mental status

BACKGROUND

The objective of the study was to assess the cerebrospinal fluid (CSF) findings in COVID-19 patients.

AIMS

This was an observational retrospective cohort from electronic medical records of hospitalized patients (n = 2655) with confirmed COVID-19 between February 15, 2020, and April 15, 2020, in 182 hospitals from a large health system in the USA. The review of data yielded to a total of 79 patients in 20 hospitals who had CSF analysis.

METHODS

Outcomes during hospitalization, including hospital length of stay, disease severity, ventilator time, and in-hospital death were recorded. Independent variables collected included patient demographics, diagnoses, laboratory values, and procedures.

RESULTS

A total of 79 patients underwent CSF analysis. Of these, antigen testing was performed in 73 patients. Ten patients had CSF analysis for general markers such as total protein, cell count, glucose, clarity, and color. Seven of the 10 cases (70%) had normal total cell count and normal white blood cell count in CSF. Sixty-three percent (5/8) had elevated total protein. Two patients had normal levels of lactate dehydrogenase (LDH) and 1 patient had significantly elevated (fourfold) neuron-specific enolase (NSE) level in CSF.

CONCLUSION

Unlike bacterial infections, viral infections are less likely to cause remarkable changes in CSF glucose, cell count, or protein. Our observations showed no pleocytosis, but mild increase in protein in the CSF of the COVID-19 patients. The fourfold elevation of NSE may have diagnostic/prognostic value as a biomarker in CSF for COVID-19 patients who have altered mental status.

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.

Neonatal neuron specific enolase, a sensitive biochemical marker of neuronal damage, is increased in preeclampsia: A retrospective cohort study

BACKGROUND

Preeclampsia leads to chronic intrauterine hypoxia by interfering with placental blood supply. We aimed to investigate whether preeclampsia exposure has an influence on central nervous system of infants, as evaluated by analyzing neonatal serum neuron specific enolase (NSE).

METHODS

This was a retrospective study including infants born in Nanfang hospital between Jan 2018 and Feb 2019 without asphyxia. They were divided into normotensive control group and preeclampsia group to compare the NSE levels. Furthermore, PE group was divided into five subgroups by lipstick of urine protein from 0 to 4+ to examine the relationship between urine protein and neonatal NSE.

RESULTS

Of the 86 selected neonates, there were 40 in control group and 46 in preeclampsia group. The NSE levels were significantly higher in infants with preeclampsia exposure compared to those infants in control group (45.504 ± 17.926 vs 30.690 ± 4.475, P < 0.0001). Multiple regression analyses revealed that the preeclampsia (β coef = 0.394, p = 0.041), 4+ proteinuria (β coef = 0.558, p < 0.0001) and 3+ proteinuria (β coef = 0.356, p = 0.005) were significant independent variables predicting elevated serum NSE concentration.

CONCLUSION

For the first time, this research has suggested the increase of neonatal NSE in preeclampsia, and the quantity of maternal proteinuria may be able to predict neonatal NSE elevation. Long-term neurodevelopmental follow-up and targeted preventive strategies are advised for this underrecognized high-risk population.

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.

Early predictors of perinatal brain damage: the role of neurobiomarkers

The early detection of perinatal brain damage in preterm and term newborns (i.e. intraventricular hemorrhage, periventricular leukomalacia and perinatal asphyxia) still constitute an unsolved issue. To date, despite technological improvement in standard perinatal monitoring procedures, decreasing the incidence of perinatal mortality, the perinatal morbidity pattern has a flat trend. Against this background, the measurement of brain constituents could be particularly useful in the early detection of cases at risk for short-/long-term brain injury. On this scenario, the main European and US international health-care institutions promoted perinatal clinical and experimental neuroprotection research projects aimed at validating and including a panel of biomarkers in the clinical guidelines. Although this is a promising attempt, there are several limitations that do not allow biomarkers to be included in standard monitoring procedures. The main limitations are: (i) the heterogeneity of neurological complications in the perinatal period, (ii) the small cohort sizes, (iii) the lack of multicenter investigations, (iv) the different techniques for neurobiomarkers assessment, (iv) the lack of consensus for the validation of assays in biological fluids such as urine and saliva, and (v), the lack of reference curves according to measurement technique and biological fluid. In the present review we offer an up-to-date overview of the most promising developments in the use of biomarkers in the perinatal period such as calcium binding proteins (S100B protein), vasoactive agents (adrenomedullin), brain biomarkers (activin A, neuron specific enolase, glial fibrillary acidic protein, ubiquitin carboxyl-terminal hydrolase-L1) and oxidative stress markers.

The Role of Brain-Derived Neurotrophic Factor and Glial Cell Line-Derived Neurotrophic Factor in Chronic Fetal Oxygen Deprivation

The aim of the study was to define the role of brain-derived and glial cell line-derived neurotrophic factors (BDNF and GDNF) in realization of compensative and adaptive mechanisms of a neonatal organism to hypoxia.

[The possibility of using neuron-specific enolase as a biomarker in the acute period of stroke]

The article presents a review of the literature on neuron-specific enolase (NSE) as a biomarker of stroke. It is shown that NSE does not allow differentiation of the ischemic and hemorrhagic process in stroke, but is suitable for determining the extent of brain tissue destruction both in the first hours of stroke and in the dynamics. The HSE analysis can be useful for monitoring the course of the disease, control of the dynamics of the pathological process, including when the size of the lesion increases, for evaluating the effectiveness of therapy and as a prognostic biomarker.

Protective role of astragalus injection in spinal cord ischemia-reperfusion injury in rats

Objectives:

To investigate the neuroprotective effect of Astragalus injection in a spinal cord ischemia-reperfusion (I/R) injury model.

Methods:

A total of 27 Sprague Dawley rats were randomly divided into 3 groups: control group (n=3), I/R group (n=12), and Astragalus injection group (Ast group, n=12). Spinal cord ischemia was induced by occlusion of the abdominal aorta above the right renal artery for 32 min. Animals in the Ast group were administered Astragalus injection (6.42 mL/kg) at 30 min before the induction of ischemia. After reperfusion for 8, 12, 24, or 48 hours, the serum neuron-specific enolase (NSE) concentration was measured by enzyme-linked immunosorbent assay (ELISA) and the aquaporin-4 (AQP4) protein level was detected by western blotting.

Results:

The pathological changes, as assessed by hematoxylin and eosin (HE) staining, were milder in the spinal cords of the Ast group compared to the I/R group. Enzyme-linked immunosorbent assay demonstrated that the NSE concentration of the Ast group was significantly lower than that of the I/R group (p<0.05). However, the NSE concentrations of the I/R and Ast groups were significantly higher than that of the control group (p=0.05). Additionally, the expression of AQP4 in the Ast group was lower than that of the I/R group at each time point.

Conclusion:

These findings indicate that Astragalus injection has a neuroprotective effect in spinal cord I/R injury by decreasing the AQP4 expression.

Circulating blood cellular glucose transporters - Surrogate biomarkers for neonatal hypoxic-ischemic encephalopathy assessed by novel scoring systems

OBJECTIVE

We examined Red Blood Cell (RBC) Glucose Transporter isoform 1 (GLUT1) and White Blood Cell (WBC) Glucose Transporter isoform 3 (GLUT3) protein concentrations to assess their potential as surrogate biomarkers for the presence of hypoxic-ischemic encephalopathy (HIE) and response to therapeutic hypothermia (TH), with respect to the neurodevelopmental prognosis.

STUDY DESIGN

A prospective feasibility study of 10 infants with HIE and 8 age-matched control subjects was undertaken. Following parental consent, blood samples were obtained at baseline before institution of TH (<6 h of life), during TH, at rewarming and post-TH in the HIE group with a baseline sample from the control group. GLUT1 and GLUT3 were measured by Enzyme-linked immunosorbent assay (ELISA) with brain biomarkers, Neuron-Specific Enolase (NSE) and Glial Fibrillary Acidic Protein (GFAP). Novel "HIE-high risk" and "Neurological" scores were developed to help identify HIE and to assess severity and prognosis, respectively.

RESULTS

RBC GLUT1 concentrations were increased at the baseline pre-TH time point in HIE versus control subjects (p = .006), normalizing after TH (p = .05). An association between GLUT1 and NSE concentrations (which was reflective of the HIE-high risk and the Neuro-scores) in controls and HIE pre-TH was seen (R² = 0.36, p = .008), with GLUT1 demonstrating 90% sensitivity and 88% specificity for presence of HIE identified by Sarnat Staging. WBC GLUT3 concentrations were low and no different in HIE versus control, and GFAP concentrations trended higher during re-warming (p = .11) and post-TH (p = .16). We demonstrated a significant difference between HIE and controls for both the "HIE-high risk" and the "Neurological" Scores. The latter score revealing the severity of clinical neurological illness correlated with the corresponding RBC GLUT1 (R² value = 0.39; p = .006).

CONCLUSION

Circulating RBC GLUT1 concentrations with NSE demonstrate a significant potential in reflecting the severity of HIE pre-TH and gauging effectiveness of TH. In contrast, the low neonatal WBC GLUT3 concentrations make discerning differences between degrees of HIE as well as assessing effectiveness of TH difficult. The HIE-high risk and Neurological scores may extend the "Sarnat staging" towards assessing severity and neuro-developmental prognosis of HIE.

Alterations of Human Plasma Proteome Profile on Adaptation to High-Altitude Hypobaric Hypoxia

For individuals migrating to or residing permanently in high-altitude regions, environmental hypobaric hypoxia is a primary challenge that induces several physiological or pathological responses. It is well documented that human beings adapt to hypobaric hypoxia via some protective mechanisms, such as erythropoiesis and overproduction of hemoglobin; however, little is known on the alterations of plasma proteome profiles in accommodation to high-altitude hypobaric hypoxia. In the present study, we investigated differential plasma proteomes of high altitude natives and lowland normal controls by a TMT-based proteomic approach. A total of 818 proteins were identified, of which 137 were differentially altered. Bioinformatics (including GO, KEGG, protein-protein interactions, etc.) analysis showed that the differentially altered proteins were basically involved in complement and coagulation cascades, antioxidative stress, and glycolysis. Validation results demonstrated that CCL18, C9, PF4, MPO, and S100A9 were notably up-regulated, and HRG and F11 were down-regulated in high altitude natives, which were consistent with TMT-based proteomic results. Our findings highlight the contributions of complement and coagulation cascades, antioxidative stress, and glycolysis in acclimatization to hypobaric hypoxia and provide a foundation for developing potential diagnostic or/and therapeutic biomarkers for high altitude hypobaric hypoxia-induced diseases.

Neural and cardiac injury markers in fetal growth restriction and their relation to perinatal outcomes

Objective:

To compare the levels of umbilical cord blood Neuron-Specific Enolase (NSE) and troponin T and venous blood gas samples between healthy newborns and growth-retarded fetuses with impaired Doppler velocity or low APGAR scores.

Materials and Methods:

This study was a prospective cohort study. The study group comprised 26 patients with intrauterine growth restriction and pathologic Doppler symptoms, and the control group included 24 healthy fetuses. Umbilical cord blood and blood gas samples were taken from all patients. The blood samples were centrifuged and sent to a laboratory to study NSE and troponin T Perinatal outcomes were evaluated from the medical records of the newborns.

Results:

Both groups were similar in terms of demographic characteristics. Fetuses with fetal growth restriction (FGR) were born earlier and had lower APGAR scores than the study group. Chronic hypoxemic fetuses in the study group had lower cord pH and HCO₃ levels. Further, troponin T levels were higher in the study group than in the control group. There were no major differences in Doppler velocity measurements.

Conclusion:

It has been understood that cardiac and neuronal injury detection on fetuses with FGR, troponin T, and NSE are indicators that can be used. In the literature there are studies with heterogeneous paradigms using different indicators to find neuronal injury. As a result of this study, it is clear that to assess neonatal prognosis, wider-scoped and comparative studies will provide more information about the subject.

Current and Emerging Therapies in the Management of Hypoxic Ischemic Encephalopathy in Neonates

Neonatal hypoxic ischemic encephalopathy (HIE) presents a significant clinical burden with its high mortality and morbidity rates globally. Therapeutic hypothermia (TH) is now standard of care for infants with moderate to severe HIE, but has not definitively changed outcomes in severe HIE. In this review, we discuss newer promising markers that may help the clinician identify severity of HIE. Therapies that are beneficial and agents that hold promise for neuroprotection are described, both for use either alone or as adjuncts to TH. These include endogenous pathway modifiers such as erythropoietin and analogues, melatonin, and remote ischemic post conditioning. Stem cells have therapeutic potential in this condition, as in many other neonatal conditions. Of the agents listed, only erythropoietin and analogues are currently being evaluated in large randomized controlled trials (RCTs). Exogenous therapies such as argon and xenon, allopurinol, monosialogangliosides, and magnesium sulfate continue to be investigated. The recognition of tertiary mechanisms of brain damage has opened up new research into therapies not only to attenuate brain damage but also to promote cell repair and regeneration in a developmentally disorganized brain long after the perinatal insult. These alternative modalities may be especially important in mild HIE and in areas of the world where there is limited access to expensive hypothermia equipment and services.

A correction formula for neuron-specific enolase measurement in hemolyzed neonatal serum samples

As a specific biomarker in neonatal hypoxic-ischemic encephalopathy (HIE), the measurement of neuron-specific enolase (NSE) has been advocated as a predictor of outcome in neurological injury. However, the measured levels of NSE may be influenced by hemolysis. In the current study, the change in the concentration of NSE in serum was measured by chemiluminescence prior to and following the addition of individual frozen and thawed red blood cells from 86 neonates that were collected within 24 h of birth. The changes in the concentration of NSE were compared with the changes in the concentration of hemoglobin (Hb), measured by the hemoglobin cyanide (HiCN) method, to establish a correction formula. The performance of the correction formula was evaluated by comparing the corrected concentration of NSE using the individual constants and the correction formula. The average individual constant of NSE from the 86 hemolyzed neonatal serum samples was 25.15±3.94 mg/g Hb. The concentration variation between NSE and Hb in neonatal sera could be described by the equation ΔNSE_serum=1.8594+24.0670 xΔHb_HiCN (r²=0.8045, P<0.001). There was no statistically significant difference in the NSE corrected results between the individual constant group and the correction formula group (Z=-1.645, P=0.100). The linear regression formula of Hb measured with the instrumental method compared with the HiCN method was Hb_instr=0.9816×Hb_HiCN+0.5596 (r²=0.9924, P<0.001). Based on these regression analyses, the correction formula for NSE in hemolyzed neonatal serum was determined as NSE_corr=NSE_meas-24.0670×Hb_HiCN-1.8594 or NSE_corr=NSE_meas-24.5181×Hb_instr+11.8609. In conclusion, hemolysis has a substantial influence on the accurate measurement of NSE in neonatal serum samples. For hemolyzed neonatal serum samples, correcting the NSE results using a correction formula is essential to evaluate the severity of neonatal hypoxic ischemic encephalopathy.

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.

The potentials and limitations of neuro-biomarkers as predictors of outcome in neonates with birth asphyxia

Perinatal asphyxia and its complication, hypoxic-ischemic encephalopathy, are still among the major causes of perinatal mortality and morbidity. Despite accurate standard postnatal monitoring procedures, the post-insult period is crucial because at a time when radiologic pictures are still silent, brain damage may already be at a subclinical stage. Against this background, the measurement of quantitative parameters, such as constituents of nervous tissue, that are able to detect subclinical lesions at a stage when routine brain monitoring procedures are still silent, could be particularly useful. Therefore, in the present review we report the potentials and limitations of biomarkers in predicting outcome in neonates complicated by perinatal asphyxia.

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.

Pathophysiology of Perinatal Hypoxic-Ischemic Encephalopathy – Biomarkers, Animal Models and Treatment Perspectives

Hypoxic-ischemic encephalopathy (HIE) is one of the leading pediatric neurological conditions causing long-term disabilities and socio-economical burdens. Nearly 20-50 % of asphyxiated newborns with HIE die within the newborn period and another third will develop severe health consequences and permanent handicaps. HIE is the result of severe systemic oxygen deprivation and reduced cerebral blood flow, commonly occurring in full-term infants. Hypoxic-ischemic changes trigger several molecular and cellular processes leading to cell death and inflammation. Generated reactive oxygen species attack surrounding cellular components resulting in functional deficits and mitochondrial dysfunction. The aim of the present paper is to review present knowledge about the pathophysiology of perinatal hypoxic-ischemic encephalopathy, especially with respect to novel treatment strategies and biomarkers that might enhance early detection of this disorder and thus improve the general outcome of patients.

Inflammatory Biomarkers of Birth Asphyxia

Although therapies in addition to whole-body cooling are being developed to treat the neonate at risk for hypoxic-ischemic encephalopathy, we have no quickly measured serum inflammatory or neuronal biomarkers to acutely and accurately identify brain injury or to follow the efficacy of therapy. This review covers inflammatory serum biomarkers in the setting of birth asphyxia that can help assess the degree or severity of encephalopathy at birth and neurodevelopmental outcomes. These biomarkers still need to be independently validated in large cohorts before they are ready for clinical implementation in practice.

Biomarkers of multiorgan injury in neonatal encephalopathy

Neonatal encephalopathy (NE) is a major contributor to neurodevelopmental deficits including cerebral palsy in term and near-term infants. The long-term neurodevelopmental outcome is difficult to predict with certainty in first few days of life. Multiorgan involvement is common but not part of the diagnostic criteria for NE. The most frequently involved organs are the heart, liver, kidneys and hematological system. Cerebral and organ involvement is associated with the release of organ specific biomarkers in cerebrospinal fluid, urine and blood. These biomarkers may have a role in the assessment of the severity of asphyxia and long-term outcome in neonates with NE.

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.

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.

Serum neuron-specific enolase levels in preterm and term newborns and in infants 1-3 months of age

BACKGROUND

Elevated serum levels of neuron-specific enolase (NSE) was initially assumed to be specific to neuronal tumors (particularly neuroblastoma), but is now known to accompany nontumoral conditions and tumors other than neuroblastomas. There is a need to establish normal ranges for NSE, especially in early infancy. The aims of this study were to determine reference values for NSE in newborns and young infants and to assess whether NSE levels in early infancy (i.e., preterm infants and term infants) differ from the adult reference range for this enzyme.

METHODS

We enrolled 140 healthy babies, which included 40 preterm newborns (3-15 days old and born at 28-42 weeks gestation), 40 term newborns (< 1 month old and born at term), and 60 young infants 1-3 months old (n = 20 per subgroup of 1-, 2-, and 3-month-old infants). The determination of NSE levels was performed by the electrochemiluminescence immunoassay (ECLIA) method using the Elecysys 2010 device (Roche Diagnostics, Mannheim, Germany). The mean serum NSE levels for the preterm newborns was 21.83 ± 15.06 ng/mL [95% confidence interval (95%CI), 16.95-26.71 ng/mL]; term newborns, 18.06 ± 12.83 ng/mL (95%CI, 13.94-22.19 ng/mL); and young infants, 9.09 ± 4.38 ng/mL (95%CI, 7.96-10.23 ng/mL). The mean serum NSE level for infants 1-3 months old was within the ECLIA kit's normal range (4.7-18 ng/mL for adults), whereas the corresponding means for the preterm and term newborns were higher (p < 0.001, for both).

CONCLUSION

Our findings suggest that adult reference values should not be applied to the preterm and term age groups.

Serum biomarkers to evaluate the integrity of the neurovascular unit

Biomarkers have the potential to enable the clinicians to screen infants for brain injury, monitor progression of disease, identify injured brain regions, assess efficacy of neuroprotective therapies, and offer hope to identify the timing of the injury, thus shedding light on the potential pathophysiology and the most effective therapy. Currently, clinicians do not routinely use biomarkers to care for neonates with Neonatal Encephalopathy (NE) and brain injury due to prenatal hypoxia-asphyxia. This review will cover potential biomarkers of the neurovascular unit in the setting of NE that (i) can help assess the degree or severity of encephalopathy at birth; (ii) can help monitor progression of disease process and efficacy of neuroprotective therapy; (iii) can help assess neurodevelopmental outcome. These biomarkers will be summarized in two categories: 1) Specific biomarkers targeting the neurovascular unit such as glial fibrillary acidic protein (GFAP), ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1), S100B, and neuron specific enolase (NSE) and 2) general inflammatory cytokines, such as interleukin-6 (IL-6), interleukin-1b (IL-1b), and pNF-H, among others.

Serum tau protein level serves as a predictive factor for neurological prognosis in neonatal asphyxia

BACKGROUND

Tau protein is a microtubule-associated protein that is present in axons. Elevated tau protein levels in cerebrospinal fluid or serum are associated with several central nervous system diseases and can indicate neuronal injury.

OBJECTIVE

In the present study, we measured and then compared serum tau protein levels between infants with neonatal asphyxia and control subjects. We examined these data to investigate the correlation between serum tau protein levels and neurological outcomes after neonatal asphyxia.

PATIENTS AND METHODS

Serum tau protein levels were determined by an enzyme-linked immunosorbent assay in 19 neonates with neonatal asphyxia. Of these 19 neonates, 3 had severe spastic tetraplegia, and 1 had west syndrome. A group of 19 unaffected neonates was included in the study as a control group.

RESULTS

Serum tau protein levels on postnatal day 3 were significantly higher in the poor outcome group than those in the good outcome (p=0.010) and control groups (p=0.006). On postnatal day 7, serum tau protein levels again were significantly higher in the poor outcome group than those in the good outcome (p=0.007) and control groups (p=0.006).

CONCLUSIONS

The present findings indicate serum tau protein levels measured on postnatal days 3 and 7 can predict neurological prognosis following neonatal asphyxia.

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.

The second elevation of neuron-specific enolase peak after ischemic stroke is associated with hemorrhagic transformation

BACKGROUND

Neuron-specific enolase (NSE) is a surrogate marker for the extent of brain damage after ischemic stroke and affords a good predictor of stroke prognosis. We hypothesized that the pattern of NSE level changes in the peripheral blood during the acute period of ischemic stroke is dependent on stroke mechanism and is associated with hemorrhagic transformation.

METHODS

Acute ischemic stroke patients visiting our center within 24 hours of symptom onset were recruited into the study. NSE levels were obtained serially at various time points after stroke, and the pattern of change was categorized into no significant change, continuously increasing, continuously decreasing, with 1 peak and with 2 peaks. Clinical, laboratory, and imaging variables were compared among the patient groups. Multivariate analysis was performed to verify the independent association between the second NSE peak and hemorrhagic transformation after adjusting for potential confounders.

RESULTS

Among 83 patients, NSE levels were stationary in 22 (26.5%) of the patients, increased in 9 (10.8%), decreased in 18 (21.7%), and showed 1 peak in 17 (20.5%) and 2 peaks in 17 (20.5%) patients. The incidence of atrial fibrillation and hemorrhagic transformation was significantly elevated (P = .02) in patients with 2 NSE peaks. Furthermore, the second NSE peak and the initial lesion volume were associated independently with hemorrhagic transformation after we adjusted for potential confounders (odds ratio = 6.844 and 1.024, P = .04 and .02, respectively).

CONCLUSIONS

Serial NSE analysis during the acute period of ischemic stroke is useful for monitoring hemorrhagic transformation and the blood-brain barrier disruption status.

Prolonged hypothermia for neurological protection

Treatment with mild hypothermia induced after cardiopulmonary resuscitation has become a standard of care, but optimal timing and duration of hypothermia remains unclear. We present a 66-year-old man admitted after an out-of-hospital cardiac arrest. Because of his severe hypoxemia, cardiopulmonary instability, and respiratory acidosis after resuscitation, he was continued on therapeutic hypothermia until his hypoxia resolved. As a result, the patient was kept at the goal hypothermic temperature of 33°C for a total of 48 hours, compared with the usual 24-hour standard, with excellent sustained neurological recovery. This case documents the usefulness of extending hypothermia when applied to severely unstable patients and suggests that a sliding-target approach may be applied on a patient-by-patient basis.

Therapeutic time window and underlying therapeutic mechanism of breviscapine injection against cerebral ischemia/reperfusion injury in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Breviscapine injection is a Chinese herbal medicine standardized product extracted from Erigeron breviscapus (Vant.) Hand.-Mazz. It has been widely used for treating cardiovascular and cerebrovascular diseases. However, the therapeutic time window and the action mechanism of breviscapine are still unclear. The present study was designed to investigate the therapeutic time window and underlying therapeutic mechanism of breviscapine injection against cerebral ischemic/reperfusion injury.

MATERIALS AND METHODS

Sprague-Dawley rats were subjected to middle cerebral artery occlusion for 2h followed by 24h of reperfusion. Experiment part 1 was used to investigate the therapeutic time window of breviscapine. Rats were injected intravenously with 50mg/kg breviscapine at different time-points of reperfusion. After 24h of reperfusion, neurologic score, infarct volume, brain water content and serum level of neuron specific enolase (NSE) were measured in a masked fashion. Part 2 was used to explore the therapeutic mechanism of breviscapine. 4-Hydroxy-2-nonenal (4-HNE), 8-hydroxyl-2'- deoxyguanosine (8-OHdG) and the antioxidant capacity of ischemia cortex were measured by ELISA and ferric-reducing antioxidant power (FRAP) assay, respectively. Immunofluorescence and western blot analysis were used to analyze the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1).

RESULTS

Part 1: breviscapine injection significantly ameliorated neurologic deficit, reduced infarct volume and water content, and suppressed the levels of NSE in a time-dependent manner. Part 2: breviscapine inhibited the increased levels of 4-HNE and 8-OHdG, and enhanced the antioxidant capacity of cortex tissue. Moreover, breviscapine obviously raised the expression of Nrf2 and HO-1 proteins after 24h of reperfusion.

CONCLUSION

The therapeutic time window of breviscapine injection for cerebral ischemia/reperfusion injury seemed to be within 5h after reperfusion. By up-regulating the expression of Nrf2/HO-1 pathway might be involved in the therapeutic mechanism of breviscapine injection.

Biomarkers of hypoxic-ischemic encephalopathy in newborns

As neonatal intensive care has evolved, the focus has shifted from improving mortality alone to an effort to improve both mortality and morbidity. The most frequent source of neonatal brain injury occurs as a result of hypoxic-ischemic injury. Hypoxic-ischemic injury occurs in about 2 of 1,000 full-term infants and severe injured infants will have lifetime disabilities and neurodevelopmental delays. Most recently, remarkable efforts toward neuroprotection have been started with the advent of therapeutic hypothermia and a key step in the evolution of neonatal neuroprotection is the discovery of biomarkers that enable the clinician-scientist to screen infants for brain injury, monitor progression of disease, identify injured brain regions, and assess efficacy of neuroprotective clinical trials. Lastly, biomarkers offer great hope identifying when an injury occurred shedding light on the potential pathophysiology and the most effective therapy. In this article, we will review biomarkers of HIE including S100B, neuron specific enolase, umbilical cord IL-6, CK-BB, GFAP, myelin basic protein, UCHL-1, and pNF-H. We hope to contribute to the awareness, validation, and clinical use of established as well as novel neonatal brain injury biomarkers.

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.