Correlation between serum neuron specific enolase and functional neurological outcome in patients of acute ischemic stroke

Multifunctional roles of γ-enolase in the central nervous system: more than a neuronal marker

Enolase, a multifunctional protein with diverse isoforms, has generally been recognized for its primary roles in glycolysis and gluconeogenesis. The shift in isoform expression from α-enolase to neuron-specific γ-enolase extends beyond its enzymatic role. Enolase is essential for neuronal survival, differentiation, and the maturation of neurons and glial cells in the central nervous system. Neuron-specific γ-enolase is a critical biomarker for neurodegenerative pathologies and neurological conditions, not only indicating disease but also participating in nerve cell formation and neuroprotection and exhibiting neurotrophic-like properties. These properties are precisely regulated by cysteine peptidase cathepsin X and scaffold protein γ1-syntrophin. Our findings suggest that γ-enolase, specifically its C-terminal part, may offer neuroprotective benefits against neurotoxicity seen in Alzheimer's and Parkinson's disease. Furthermore, although the therapeutic potential of γ-enolase seems promising, the effectiveness of enolase inhibitors is under debate. This paper reviews the research on the roles of γ-enolase in the central nervous system, especially in pathophysiological events and the regulation of neurodegenerative diseases.

Fluid biomarkers of the neurovascular unit in cerebrovascular disease and vascular cognitive disorders: A systematic review and meta-analysis

Background

The disruption of the neurovascular unit (NVU), which maintains the integrity of the blood brain barrier (BBB), has been identified as a critical mechanism in the development of cerebrovascular and neurodegenerative disorders. However, the understanding of the pathophysiological mechanisms linking NVU dysfunction to the disorders is incomplete, and reliable blood biomarkers to measure NVU dysfunction are yet to be established. This systematic review and meta-analysis aimed to identify biomarkers associated with BBB dysfunction in large vessel disease, small vessel disease (SVD) and vascular cognitive disorders (VCD).

Methods

A literature search was conducted in PubMed, EMBASE, Scopus and PsychINFO to identify blood biomarkers related to dysfunction of the NVU in disorders with vascular pathologies published until 20 November 2023. Studies that assayed one or more specific markers in human serum or plasma were included. Quality of studies was assessed using the Newcastle-Ottawa Quality Assessment Scale. Effects were pooled and methodological heterogeneity examined using the random effects model.

Results

A total of 112 studies were included in this review. Where study numbers allowed, biomarkers were analysed using random effect meta-analysis for VCD (1 biomarker; 5 studies) and cerebrovascular disorders, including stroke and SVD (9 biomarkers; 29 studies) while all remaining biomarkers (n = 17 biomarkers; 78 studies) were examined through qualitative analysis. Results of the meta-analysis revealed that cerebrospinal fluid/serum albumin quotient (Q-Alb) reliably differentiates VCD patients from healthy controls (MD = 2.77; 95 % CI = 1.97-3.57; p < 0.0001) while commonly measured biomarkers of endothelial dysfunction (VEGF, VCAM-1, ICAM-1, vWF and E-selectin) and neuronal injury (NfL) were significantly elevated in vascular pathologies. A qualitative assessment of non-meta-analysed biomarkers revealed NSE, NfL, vWF, ICAM-1, VCAM-1, lipocalin-2, MMP-2 and MMP-9 levels to be upregulated in VCD, although these findings were not consistently replicated.

Conclusions

This review identifies several promising biomarkers of NVU dysfunction which require further validation. A panel of biomarkers representing multiple pathophysiological pathways may offer greater discriminative power in distinguishing possible disease mechanisms of VCD.

Serum biomarkers of hypoxic-ischemic brain injury

Brain injury is a multifaceted condition arising from nonspecific damage to nervous tissue. The resulting cognitive developmental impairments reverberate through patients' lives, affecting their families, and even the broader economic landscape. The significance of early brain injury detection lies in its potential to stave off severe consequences and enhance the effectiveness of tailored therapeutic interventions. While established methods like neuroimaging and neurophysiology serve as valuable diagnostic tools, their demanding nature restricts their accessibility, particularly in scenarios such as small hospitals, nocturnal or weekend shifts, and cases involving unstable patients. Hence, there is a pressing need for more accessible and efficient diagnostic avenues. Among the spectrum of brain injuries, hypoxic-ischemic encephalopathy stands out as a predominant affliction in the pediatric population. Diagnosing brain injuries in newborns presents challenges due to the subjective nature of assessments like Apgar scores and the inherent uncertainty in neurological examinations. In this context, methods like magnetic resonance and ultrasound hold recommendations for more accurate diagnosis. Recognizing the potential of serum biomarkers derived from blood samples, this paper underscores their promise as a more expedient and resource-efficient means of assessing brain injuries. The review compiles current insights into serum biomarkers, drawing from experiments conducted on animal models as well as human brain pathologies. The authors aim to elucidate specific characteristics, temporal profiles, and the available corpus of experimental and clinical data for serum biomarkers specific to brain injuries. These include neuron-specific enolase (NSE), ubiquitin carboxy-terminal hydrolase L1 (UCH-L1), S100 calcium-binding protein beta (S100B), glial fibrillary acidic protein (GFAP), and high-mobility-group-protein-box-1 (HMGB1). This comprehensive endeavor contributes to advancing the understanding of brain injury diagnostics and potential avenues for therapeutic intervention.

Cerebrospinal Fluid and Serum Biomarker Insights in Aneurysmal Subarachnoid Haemorrhage: Navigating the Brain-Heart Interrelationship for Improved Patient Outcomes

The pathophysiological mechanisms underlying severe cardiac dysfunction after aneurysmal subarachnoid haemorrhage (aSAH) remain poorly understood. In the present study, we focused on two categories of contributing factors describing the brain-heart relationship. The first group includes brain-specific cerebrospinal fluid (CSF) and serum biomarkers, as well as cardiac-specific biomarkers. The secondary category encompasses parameters associated with cerebral autoregulation and the autonomic nervous system. A group of 15 aSAH patients were included in the analysis. Severe cardiac complications were diagnosed in seven (47%) of patients. In the whole population, a significant correlation was observed between CSF S100 calcium-binding protein B (S100B) and brain natriuretic peptide (BNP) (rS = 0.62; p = 0.040). Additionally, we identified a significant correlation between CSF neuron-specific enolase (NSE) with cardiac troponin I (rS = 0.57; p = 0.025) and BNP (rS = 0.66; p = 0.029), as well as between CSF tau protein and BNP (rS = 0.78; p = 0.039). Patients experiencing severe cardiac complications exhibited notably higher levels of serum tau protein at day 1 (0.21 ± 0.23 [ng/mL]) compared to those without severe cardiac complications (0.03 ± 0.04 [ng/mL]); p = 0.009. Impaired cerebral autoregulation was noted in patients both with and without severe cardiac complications. Elevated serum NSE at day 1 was related to impaired cerebral autoregulation (rS = 0.90; p = 0.037). On the first day, a substantial, reciprocal correlation between heart rate variability low-to-high frequency ratio (HRV LF/HF) and both GFAP (rS = -0.83; p = 0.004) and S100B (rS = -0.83; p = 0.004) was observed. Cardiac and brain-specific biomarkers hold the potential to assist clinicians in providing timely insights into cardiac complications, and therefore they contribute to the prognosis of outcomes.

Blood-Based Biomarkers for Neuroprognostication in Acute Brain Injury

Acute brain injury causes loss of functionality in patients that often is devastating. Predicting the degree of functional loss and overall prognosis requires a multifaceted approach to help patients, and more so their families, make important decisions regarding plans and goals of care. A variety of blood-based markers have been studied as one aspect of this determination. In this review, we discuss CNS-derived and systemic markers that have been studied for neuroprognostication purposes. We discuss the foundation of each protein, the conditions in which it has been studied, and how the literature has used these markers for interpretation. We also discuss challenges to using each marker in each section as well.

Neuron-specific enolase in hypertension patients with acute ischemic stroke and its value forecasting long-term functional outcomes

BACKGROUND

Neuron Specific Enolase (NSE), a neuro-biochemical protein marker, may correlate with the prognosis of stroke patients. Moreover, hypertension is the most common comorbidities in patients with acute ischemic stroke (AIS), and the relationship between NSE levels and long-term functional outcomes in such an increasingly large population is unclear. The aim of the study was to investigate the relationships mentioned above and optimize the prediction models.

METHODS

From 2018 to 2020, 1086 admissions for AIS were grouped as hypertension and non-hypertension, while hypertension group was randomly divided into development and validation cohorts for internal validation. The severity of the stroke was staged by National Institutes of Health Stroke Scale (NIHSS) score. Stroke prognosis after 1 year of follow up was documented by modified Rankin Scale (mRS) score.

RESULTS

Analysis revealed the following findings:(i) Serum NSE levels increased greatly in hypertension subjects with poor functional outcomes(p = 0.046). However, there was no association in non-hypertension individuals(p = 0.386). (ii) In addition to the conventional factors (age and NIHSS score), NSE (OR:1.241, 95% CI: 1.025-1.502) and prothrombin time were significantly related to the incidence of unfavorable outcomes. (iii)Based on the above four indicators, a novel nomogram was established to predict the prognosis of stoke in hypertension patients with the c-index values of 0.8851.

CONCLUSIONS

Overall, high baseline NSE is associated with poor 1-year AIS outcomes in hypertension patients, suggesting NSE may be a potential prognostic and therapeutic target for stroke in hypertension patients.

The Relationship Between Neuron-Specific Enolase and Clinical Outcomes in Patients Undergoing Mechanical Thrombectomy

Purpose

Neuron-specific enolase (NSE) is considered a biomarker for the severity of nervous system diseases. We sought to explore whether serum NSE concentration in ischemic stroke patients undergoing mechanical thrombectomy (MT) is related to 3-month functional outcome and symptomatic intracranial hemorrhage (sICH).

Patients and Methods

We retrospectively collected the data of acute ischemic stroke patients with anterior circulation infarction receiving MT within 6 h in our stroke center. Favorable outcome and poor outcome at 3 months were defined as modified Rankin Scale (mRS) score 0-2 and 3-6, respectively. sICH was defined according to the Heidelberg bleeding classification. We used multivariate logistic regression model and receiver operating characteristic curves to investigate the correlation between NSE and clinical outcomes.

Results

Among the 426 patients enrolled, 40 (9.4%) patients developed sICH. Three-month favorable outcome in 160 (37.6%) and poor outcome in 266 (62.4%) patients were observed. Serum NSE levels was significantly correlated with 3-month mRS score (R = 0.473, P < 0.001). A cutoff value of 15.29 and 23.12 ng/mL for serum NSE was detected in discriminating 3-month poor outcome (area under the curve, 0.724) and sICH (area under the curve, 0.716), respectively. Multivariate analysis showed that high serum NSE levels were independently associated with 3-month poor outcome (odds ratio [OR] 5.049, 95% confidence interval [CI] 2.933-8.689, P<0.001) and sICH (OR 5.111, 95% CI 2.210-11.820, P < 0.001).

Conclusion

Our study demonstrated that high serum NSE levels after receiving MT were independently associated with 3-month poor outcome and sICH in acute ischemic stroke patients. Serum NSE levels could be a good predictor of clinical outcomes for patients receiving MT.

A Pathophysiological Approach To Current Biomarkers

Biomarkers are necessary for screening and diagnosing numerous diseases, predicting the prognosis of patients, and following-up treatment and the course of the patient. Everyday new biomarkers are being used in clinics for these purposes. This section will discuss the physiological roles of the various current biomarkers in a healthy person and the pathophysiological mechanisms underlying the release of these biomarkers. This chapter aims to gain a new perspective for evaluating and interpreting the most current biomarkers.

Serum S100B and NSE Levels Correlate With Infarct Size and Bladder-Bowel Involvement Among Acute Ischemic Stroke Patients

Objectives Stroke is a major global health concern. Due to limited availability of neuroimaging particularly in rural and regional areas in India as well as its limitation, the interest in use of biochemical markers for stroke diagnosis, severity, and prognosis is increasing. Only a handful of studies on stroke biomarkers have been conducted in India. Hence, this study was conducted to investigate the correlation of serum neuron-specific enolase (NSE) and S100 calcium-binding protein B (S100B) levels with stroke severity according to infarct size in acute ischemic stroke patients.

Material and Methods Sixty stroke patients were recruited for the study and were evaluated. Noncontrast computed tomography (CT) scan of the brain was performed for all patients within 48 hours of onset of symptoms. Infarct volume was measured by evaluating dimensions in three planes on CT head. Serum NSE and S100B levels were measured by commercially available immunoassay kits. Continuous data was represented as mean ± standard deviation. Categorical data was expressed in terms of percentages and proportions. Pearson's correlation coefficient was applied to assess correlation between NSE and S100B and infarct size. Infarct size was classified arbitrarily into three groups according to infarct volume (low, moderate, and large) and analysis of variance was applied for comparing mean S100B and NSE levels in the three groups. To assess the independent predictors of infarct size among stroke cases, multivariate logistic regression analysis was used. Association between serum S100B or NSE levels and clinical features was done by the Mann–Whitney U test.

Results Correlation between serum S100B protein levels and NSE with larger infarct volume was highly significant (r(S100B) = 0.611, p (S100B) < 0.0001; r(NSE) = 0.258, p(NSE) = 0.047). Using multivariate regression analysis, bladder and bowel involvement, prior stroke history, and dyslipidemia among stroke patients correlated with a larger infarct size. Mann–Whitney U test showed both NSE and S100B levels were significantly associated with bladder bowel involvement among stroke cases.

Conclusion There was a positive correlation between serum S100B and NSE levels with infarct size. In addition, bladder-bowel involvement among stroke patients was associated with increased S100B levels. Therefore, levels of protein S100B and NSE may serve as indicator of infarct size and may be predictors of severe clinical presentations of acute ischemic stroke.

Relationship between Neuron-specific Enolase Serum Levels with Lesion Volume and Clinical Outcome in Acute Stroke Patients

BACKGROUND: Neuron-specific enolase (NSE) is released in the cerebrospinal fluid and bloodstream in response to brain damage. Serum NSE levels can be used as a marker of brain nerve cells either in ischemic or hemorrhagic stroke, associated with lesion volume and functional outcome. AIM: The aim of the study was to evaluate the correlation between NSE serum level with lesion volume and functional outcome in acute stroke patients. METHODS: A cross-sectional study was conducted on 29 patients with ischemic stroke and 29 hemorrhagic strokes admitted to Haji Adam General Hospital. All the subjects were assessed with the National Institute of Health Stroke Scale (NIHSS) score, modified Rankin scale (mRS), and assessment of lesion volume. RESULTS: Subjects consist of 27 male (46.4%) and 31 female (53.4%), with mean age of 61.67 ± 12.26 years. The mean serum NSE levels in stroke patients were 19.79 ± 8.88 ng/ml and lesion volume was 25.09 ± 24.52 ml. There was a significant positive correlation of increase in serum NSE levels with infarct volume (r = 0.863 and p < 0.001) and hemorrhagic volume (r = 0.644 and p < 0.001) and clinical outcome assessed by NIHSS score (r = 0.761 and p < 0.001) and mRS score (r = 0.762 and p < 0.001) in ischemic stroke and NIHSS score (r = 0.525 and p = 0.003), and mRS score (r = 0.468 and p = 0.010) in hemorrhagic stroke. CONCLUSION: High NSE serum levels in the acute phase were associated with lesion volume and poor outcomes in stroke patients.

Biomarkers Predictive of Long-Term Outcome After Ischemic Stroke: A Meta-Analysis

BACKGROUND AND PURPOSE

The goal of this study was to systematically review the utility of serum biomarkers in the setting of ischemic stroke (IS) to predict long-term outcome.

METHODS

A systematic literature review was performed using the PubMed and MEDLINE databases for studies published between 1986-2018. All studies assessing long-term functional outcome (defined as 30 days or greater) following IS with respect to serum biomarkers were included. Data were extracted and pooled using a meta-analysis of odds ratios.

RESULTS

Of the total 2928 articles in the original literature search, 183 studies were ultimately selected. A total of 127 serum biomarkers were included. Biomarkers were grouped into several categories: inflammatory (32), peptide/enzymatic (30), oxidative/metabolic (28), hormone/steroid based (23), and hematologic/vascular (14). The most commonly studied biomarkers in each category were found to be CRP, S100β, albumin, copeptin, and D-dimer. With the exception of S100β, all were found to be statistically associated with >30-day outcome after ischemic stroke.

CONCLUSIONS

Serum-based biomarkers have the potential to predict functional outcome in IS patients. This meta-analysis has identified CRP, albumin, copeptin, and D-dimer to be significantly associated with long-term outcome after IS. These biomarkers have the potential to serve as a platform for prognosticating stroke outcomes after 30 days. These serum biomarkers, some of which are routinely ordered, can be combined with imaging biomarkers and used in artificial intelligence algorithms to provide refined predictive outcomes after injury. Ultimately these tools will assist physicians in providing guidance to families with regards to long-term independence of patients.

Prediction of delayed neuropsychiatric sequelae after carbon monoxide poisoning via serial determination of serum neuron-specific enolase levels

BACKGROUND

Neuron-specific enolase (NSE) is released into serum when nerve cells are damaged, and the levels thereof are used to determine neurological prognosis in patients who have suffered cardiac arrest or stroke. Delayed neuropsychiatric sequelae (DNS), a major complication of carbon monoxide poisoning (COP), can be caused by inflammatory response which is a mechanism of neuronal injury in cardiac arrest and stroke. NSE is known as a predictor of neurological prognosis in ischemic brain injury after cardiac arrest, and it is also reported as a predictor of DNS in acute COP. When serum NSE is measured serially in cardiac arrest patients, the best time to predict neurological prognosis is known at 48-72 h, but there are no studies analyzing serial serum NSE in acute COP. Thus, we explored whether serum NSE levels measured three times at 24 h intervals after COP predicted the development of DNS.

METHODS

This prospective observational study was conducted on patients treated for COP from May 2018 to April 2020 in a tertiary care hospital in Korea. Neuron-specific enolase levels were assessed 24, 48, and 72 h after presentation at hospital. We used logistic regression to explore the association between NSE levels and DNS development.

RESULTS

The NSE level was highest at 48 h, and the difference between the DNS group and the non-DNS group was greatest on the same time point. On multivariable logistic regression analysis, the NSE level at 48 h of >20.98 ng/mL (odds ratio [OR], 3.570; 95% confidence interval [CI], 1.412-9.026; P = .007) and the initial Glasgow Coma Scale (GCS) score of <9 (OR, 4.559; 95% CI, 1.658-0.12.540; P = .003) was statistically significant for DNS development.

CONCLUSION

Early identification of those who will experience DNS in acute COP patients is clinically important for deciding treatment. In this study, we revealed that NSE level of >20.98 ng/mL at 48 h time point can be used as an independent predictor of DNS (OR, 3.570; 95% CI, 1.412-9.026; P = .007; AUC, 0.648).

Isobaric Tags for Relative and Absolute Quantitation-Based Quantitative Serum Proteomics Analysis in Ischemic Stroke Patients With Hemorrhagic Transformation

Hemorrhagic transformation (HT), which occurs with or without reperfusion treatments (thrombolysis and/or thrombectomy), deteriorates the outcomes of ischemic stroke patients. It is essential to find clinically reliable biomarkers that can predict HT. In this study, we screened for potential serum biomarkers from an existing blood bank and database with 243 suspected acute ischemic stroke (AIS) patients. A total of 37 patients were enrolled, who were diagnosed as AIS without receiving reperfusion treatment. They were divided into two groups based on whether they were accompanied with HT or not (five HT and 32 non-HT). Serum samples were labeled by isobaric tags for relative and absolute quantitation (iTRAQ) and analyzed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) and compared under NCBInr database. A total of 647 proteins in sera samples were captured, and the levels of 17 proteins (12 upregulated and five downregulated) were significantly different. These differentially expressed proteins were further categorized with Gene Ontology functional classification annotation and Kyoto Encyclopedia of Genes and Genomes metabolic pathway analysis into biological processes. Further protein–protein interaction analysis using String database discovered that, among the differentially expressed proteins, 10 pairs of proteins were found to have crosstalk connections, which may have direct (physical) and indirect (functional) interactions for the development of HT. Our findings suggest that these differentially expressed proteins could serve as potential biomarkers for predicting HT after ischemic stroke.

Prognostic Value of Investigating Neuron-Specific Enolase in Patients with Ischemic Stroke

The aim of the study was to assess the prognostic value of the plasma neuron-specific enolase (NSE) level as a predictor of functional outcome and motor function recovery in the acute period of ischemic stroke (IS).

The effect of doxycycline on neuron-specific enolase in patients with traumatic brain injury: a randomized controlled trial

Objective:

We aimed to examine the effect of doxycycline on serum levels of neuron-specific enolase (NSE), a marker of neuronal damage in traumatic brain injury (TBI) patients.

Methods:

Patients were randomly assigned into two groups (n = 25 each) to receive either placebo or doxycycline (200 mg daily), with their standard management for 7 days.

Results:

NSE serum levels in the doxycycline and control groups on day 3 were 14.66 ± 1.78 versus 18.09 ± 4.38 ng/mL, respectively (p = 0.008), and on day 7 were 12.3 ± 2.0 versus 16.43 ± 3.85 ng/mL, respectively (p = 0.003). Glasgow Coma Scale (GCS) on day 7 was 11.90 ± 2.83 versus 9.65 ± 3.44 in the doxycycline and control groups, respectively (p = 0.031). NSE serum levels and GCS scores were negatively correlated (r = −0.569, p < 0.001).

Conclusion:

Adjunctive early use of doxycycline might be a novel option that halts the ongoing secondary brain injury in patients with moderate to severe TBI. Future larger clinical trials are warranted to confirm these findings.

Effects of stellate ganglion block on early brain injury in patients with subarachnoid hemorrhage: a randomised control trial

Background

Subarachnoid hemorrhage (SAH) is a common neurosurgical emergency, and early brain injury (EBI) plays an important role in acute brain injury of SAH. Our objective is to investigate the effect of stellate ganglion block (SGB) on the clinical prognosis of patients with SAH (registration number ChiCTR2000030910).

Methods

A randomized controlled trial was conducted with 102 participants. Patients with SAH were assigned to the SGB or nSGB group. Patients in the SGB group received SGB four times (once every other day starting on the day of the surgery). In contrast, patients in the nSGB group only received standard care. Data were collected on the day before surgery (T0) and on the 1^st (T1), 3^rd (T2) and 7^th day (T3) after surgery. The primary outcomes included EBI markers (including IL-1β, IL-6, TNF-α, ET-1, NPY, NSE and S100β), the mean cerebral blood flow velocity of the middle cerebral artery (Vm-MCA) and the basilar artery (Vm-BA). All cases were followed up for 6 months after surgery.

Results

The levels of the EBI markers in both groups were higher at T1–T3 than at T0 (P<0.05), and the Vm-MCA and Vm-BA were also increased at the same times. However, the levels of the EBI markers were lower in the SGB group than in the nSGB group (P<0.05), and the increases of Vm-MCA and Vm-BA were also lower (P<0.05). The prognosis score and neurological deficit were better in the SGB group than in the nSGB group (P<0.05).

Conclusions

SGB can improve the prognosis of SAH patients by inhibiting the inflammatory response during EBI and by reducing endothelial dysfunction and relieving CVS.

Trial registration

Clinical trial number: ChiCTR2000030910; Registry URL: Chinese Clinical Trial Registry; Principal investigator's name: Ying Nie; Date of Trial registration: March, 2020 (retrospectively registered).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-020-01215-3.

Blood Biomarkers for Detection of Brain Injury in COVID-19 Patients

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus attacks multiple organs of coronavirus disease 2019 (COVID-19) patients, including the brain. There are worldwide descriptions of neurological deficits in COVID-19 patients. Central nervous system (CNS) symptoms can be present early in the course of the disease. As many as 55% of hospitalized COVID-19 patients have been reported to have neurological disturbances three months after infection by SARS-CoV-2. The mutability of the SARS-COV-2 virus and its potential to directly affect the CNS highlight the urgency of developing technology to diagnose, manage, and treat brain injury in COVID-19 patients. The pathobiology of CNS infection by SARS-CoV-2 and the associated neurological sequelae of this infection remain poorly understood. In this review, we outline the rationale for the use of blood biomarkers (BBs) for diagnosis of brain injury in COVID-19 patients, the research needed to incorporate their use into clinical practice, and the improvements in patient management and outcomes that can result. BBs of brain injury could potentially provide tools for detection of brain injury in COVID-19 patients. Elevations of BBs have been reported in cerebrospinal fluid (CSF) and blood of COVID-19 patients. BB proteins have been analyzed in CSF to detect CNS involvement in patients with infectious diseases, including human immunodeficiency virus and tuberculous meningitis. BBs are approved by the U.S. Food and Drug Administration for diagnosis of mild versus moderate traumatic brain injury and have identified brain injury after stroke, cardiac arrest, hypoxia, and epilepsy. BBs, integrated with other diagnostic tools, could enhance understanding of viral mechanisms of brain injury, predict severity of neurological deficits, guide triage of patients and assignment to appropriate medical pathways, and assess efficacy of therapeutic interventions in COVID-19 patients.

Diagnostic and prognostic value of serum miR-9-5p and miR-128-3p levels in early-stage acute ischemic stroke

OBJECTIVES

To investigate the clinical utility of serum microRNA levels (miR-9-5p and miR-128-3p) in the diagnosis and prognosis of early-stage acute ischemic stroke (AIS).

METHODS

We compared the differences in serum miR-9-5p and miR-128-3p levels between patients with AIS and healthy individuals (controls). The serum levels of miR-9-5p and miR-128-3p were quantified using quantitative real-time PCR, and the association of each miRNA with AIS was determined using receiver operator characteristic curve analysis. The predictive value of these indices in the diagnosis of early-stage AIS was evaluated in conjunction with that of computed tomography findings and neuron-specific enolase levels. The prognosis of patients with AIS was evaluated three months after their discharge from hospital using the modified Rankin scale, which classifies the prognosis as either favorable or poor. Logistic regression analysis was used to analyze the correlation between miR-9-5p and miR-128-3p levels and patient prognosis.

RESULTS

The serum levels of miR-9-5p and miR-128-3p were upregulated in patients with AIS relative to those in healthy individuals. A pronounced correlation was identified between serum miR-9-5p and miR-128-3p levels and patient prognosis, with high levels of both miRNAs being associated with poor patient outcomes.

CONCLUSION

Assessment of serum miR-9-5p and miR-128-3p levels is important for the early diagnosis and prognosis of AIS.

[Assessment of the levels of neuron-specific enolase and BDNF at the stages of rehabilitation in the acute and early recovery periods of ischemic stroke]

BACKGROUND

The issue of the diagnostic significance and clinical value of neuron-specific enolase (NSE) and brain-derived neurotropic factor (BDNF) in the acute period of stroke remains controversial. Therefore, it is advisable to study the correlation of biomarkers with the clinical characteristics of stroke in the time period of early recovery.

OBJECTIVE

To monitor NSE and BDNF levels in peripheral blood, to analyze the clinical and laboratory correlations in patients with ischemic stroke at the stages of medical rehabilitation in the early recovery period.

MATERIAL AND METHODS

Forty-nine patients with ischemic stroke in the middle cerebral artery were examined. The observation period is 90 days. Observation Points are Day 1; Day 14; Day 45; Day 90. The National Institute of Health Stroke Scale (NIHSS), the Fugle-Meyer Scale (FMA), the Modified Rankin Scale (mRS) were administered. NSE was determined in blood serum by enzyme-linked immunosorbent assay, BDNF was analyzed on a multiplex analyzer.

RESULTS AND CONCLUSION

NSE_Day1 in patients was significantly higher than in the comparison group (p_{Day1-comparison group}<0.001) with a trend to a maximum decrease on the 90th day of stroke (p_Day1-90<0.001). BDNF_Day1 turned out to be lower than in the comparison group (p_{Day1-comparison group}=0.006) and significantly increased by the 14th day of the stroke (p_Day1-14<0.001; p_{Day14-comparison group}=0.637). A negative correlation was found between a decrease in NSE_Day14 and an increase in BDNF_Day14 (r= -0.349; p=0.05). A positive correlation was found between an increase in BDNF_Day14 and a decrease in mRS scores _Day90 (r=0.499, p=0.035). Outcomes in patients in group 1 (after stages I and II of rehabilitation) on the assessment scales were significantly better than in patients discharged after stage I for outpatient monitoring - group 2 (p<0.05). In group 1, BDNF_Day90 did not differ from BDNF_Day14 (p_{Day14-90-Group1}=0.17), and in group 2 it was significantly lower by the end of the early recovery period (p_{Day14-90-Group2}=0.002).

The role of light desynchronosis in the development of stress-induced aging

The long-term change of the light mode for three months – light desynchronosis, disturbs the rhythm of the signals received from the external pacemaker. As a result of the study, it was found that a long-term change in the light mode and a violation of the rhythmicity of signals received from an external pacemaker contributes to the activation of ROS formation as triggers for bioenergetic processes in the cell. At the same time, changing the light mode disrupts the balance of oxygen in the cell and this is a provoking factor for the stress of the antioxidant cell system. The resulting tissue hypoxia in chronic light desynchronosis disrupts the bioenergetic potential of the cell, contributing to the development of pathophysiological processes and the death of neurons. Therefore, a violation of the balance of the pro-oxidant and anti-oxidant systems leads to destructive processes in the brain. A significant change in the concentration of the neurotrohic markers indicates destructive processes in the brain tissues. Summarizing the above, we conclude that light desynchronosis is directly involved in the ROS-dependent stress-induced aging of brain cells and in that way, to the progression of processes that lead to aging of the body.

[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.

[In-hospital outcomes of carotid endarterectomy depending on severity of contralateral lesion]

AIM

To compare in-hospital outcomes of carotid endarterectomy (CEE) in patients with different lesion of contralateral internal carotid artery (ICA).

MATERIAL AND METHODS

There were 730 CEE procedures in patients with bilateral ICA lesion for the period 2011-2016. All patients were divided into 4 groups depending on contralateral ICA stenosis grade: group 1 - stenosis up to 60% (42.6%, n=311); group 2 - 60-90% (18.7%, n=137); group 3 - 90-99% (25.9%, n=189); group 4 - occlusion (12.7%, n=93). Endpoints were unfavorable cardiovascular events including death, myocardial infarction (MI), stroke/TIA, significant hemorrhage by BARC scale (Bleeding Academic Research Consortium).

RESULTS

In-hospital mortality and incidence of MI, stroke/TIA were similar in all groups. However, there were no cardiovascular complications in patients with critical contralateral stenosis or occlusion. Bleeding followed by redo surgery was the most frequent complication. Overall incidence of adverse cardiovascular events did not exceed 1.23%.

CONCLUSION

There was no correlation between contralateral ICA stenosis and incidence of in-hospital adverse events including death, MI, stroke/TIA. Currently, technique of CEE is well developed that is associated with low incidence of postoperative complications.

Predicting functional outcome of ischemic stroke patients in Romania based on plasma CRP, sTNFR-1, D-Dimers, NGAL and NSE measured using a biochip array

In cerebral ischemia, evaluation of multiple biomarkers involved in various pathological pathways is a useful tool in assessing the outcome of the patients even from the early stages of the disease. In this study we investigated the utility of a panel of 5 peripheral biomarkers of inflammatory status, neuronal destruction and secondary fibrinolysis in the acute phase of ischemia, and evaluated the impact of these biomarkers on functional outcome after ischemic stroke. The 5 biomarkers (plasma CRP, D-Dimers, sTNFR-1, NGAL and NSE) were measured using a biochip array technology. Eighty nine patients in Romania were divided into 2 subgroups using the modified Rankin Scale evaluated at 3 months after ischemic stroke; the possible impact of analyzed biomarkers on unfavorable functional outcome was tested by binomial logistic regression. The subgroup with unfavorable outcome had higher concentrations of CRP, NGAL, sTNFR-1 and D-dimers, but CRP and NGAL values were not statistically different between the two subgroups. The univariate logistic regression analysis of plasma biomarkers revealed that CRP, D-Dimers, NGAL, sTNFR-1 were significant predictors of unfavorable clinical outcome. In the case of D-Dimers and sTNFR-1 we noticed an increased discrimination ability (versus baseline clinical model) to classify poor functional outcome with a tendency toward statistical signification. During the acute phase of the ischemic stroke, plasma concentrations of CRP, D-Dimers and sTNFR-1 were elevated in unfavorable outcome patients. D-Dimers and sTNFR-1 were independent predictors of poor outcome at 3 months after ischemic stroke. The biochip array technology offers the possibility to simultaneously measure several parameters involved in multiple pathophysiological pathways, in a small sample volume.

Plasma Translocator Protein Levels and Outcomes of Acute Ischemic Stroke: A Pilot Study

Translocator protein 18 kDa (TSPO) has been used as a biomarker of brain injury and inflammation in various neurological diseases. In this study, we measured the level of TSPO in acute ischemic stroke patients and determined its association with the degree of stroke severity and its ability to predict stroke functional outcomes. In total, 38 patients with moderate to severe acute ischemic stroke were enrolled. Demographic information, cerebral risk factors, and stroke severity were examined at the baseline. The National Institutes of Health Stroke Scale, modified Rankin Scale, and Barthal Index were assessed at discharge as measures of poor functional outcomes and severe disability. The baseline fasting plasma TSPO level was assessed within 24 h after the incident stroke and during hospitalization (on days 8-10). The proportion of patients with poor functional outcomes was significantly higher in the higher-TSPO group (compared to the lower group) in terms of clinical worsening (odds ratio (OR) = 11.69, 95% confidence interval (CI) = 2.08-65.6), poor functional outcomes (OR = 10.5, 95% CI = 1.14-96.57), and severe disability (OR = 4.8, 95% CI = 1.20-19.13). Plasma TSPO may be intimately linked with disease progression and worse functional outcomes in acute ischemic stroke patients.

Nitrosative stress indices in dogs with neurological form of canine distemper

This is a prospective, controlled, randomized clinical study to evidence the role of nitrosative stress in development of overt neurological sign of canine distemper (CD). The enrollment of cases wasa made on basis of overt sign of CD (n=139) and the findings were compared with apparently healthy dogs (n=15). The CD specific immunoglobulins resulted in 94 confirmed positive cases. The nitric oxide (NO) and neuronal nitric oxide synthase (nNOS) concentration in cerebrospinal fluid (CSF) (18.08 ± 2.76, 415.84 ± 46.24, respectively) and plasma (32.68 ± 4.31, 321.31 ± 102.30, respectively) were significantly (P<0.05) elevated as compared to healthy control group. The concentration of neuron specific enolase (NSE) in CSF and plasma were also significantly (P<0.05) higher in dogs suffering from CD. The significant differences in other biochemical parameters like total protein, albumin and globulin were found in the CSF of dogs compared with healthy control. The author concludes that NO plays a role in pathophysiology of neurological form of CD and nNOS and NSE estimation in CSF and plasma could help in making early diagnosis of clinical cases.

Serum neuron-specific enolase levels at presentation and long-term neurological sequelae after acute charcoal burning-induced carbon monoxide poisoning

OBJECTIVE

This study aimed to investigate whether clinical parameters and serum neuron-specific enolase (NSE) levels measured at emergency department (ED) presentation help stratify the risk of acute or delayed persistent severe neurological sequelae after acute carbon monoxide (CO) poisoning induced by charcoal burning.

METHODS

This retrospective study included 236 patients who suffered from CO poisoning. Demographic information, serum NSE levels measured in the ED, treatment, clinical course, and long-term neurological outcomes were recorded.

RESULTS

The median serum NSE level at presentation was 15.5 (10.9-22.7) ng/mL. No differences were observed in the duration of CO exposure; the initial Glasgow Coma Scale (GCS) score; the levels of arterial HCO₃^-, white blood cells (WBCs), C-reactive protein (CRP) or troponin I; or the frequency of abnormal diffusion-weighted imaging finding at presentation among the groups with different serum NSE levels at presentation. The incidences of acute and delayed persistent neurologic sequelae assessed at 22.3 months after acute charcoal CO poisoning were 5.1% and 8.5%, respectively. No difference in the NSE level was observed between patients stratified according to long-term neurological status. According to the multinomial logistic regression analysis, age, serum CRP levels and the initial GCS score were risk factors for the two types of persistent severe neurological sequelae, whereas troponin I levels were associated only with the acute persistent severe neurological sequelae. However, the adjusted NSE level was not a risk factor for any persistent neurological sequelae.

CONCLUSIONS

Serum NSE levels at presentation were not correlated with the risk of acute or delayed persistent neurological sequelae. Further studies with blood sampling at optimal time points and serial measurements should be conducted. Age, initial GCS score, and CRP levels may be risk factors for persistent severe neurological sequelae.

Serum neuron specific enolase is increased in pediatric acute encephalitis syndrome

PURPOSE

This study aimed to investigate whether serum neuron-specific enolase (NSE) was expressed in acute encephalitis syndrome (AES) that causes neuronal damage in children.

METHODS

This prospective observational study was conducted in the pediatric neurology ward of Soetomo Hospital. Cases of AES with ages ranging from 1 month to 12 years were included. Cases that were categorized as simple and complex febrile seizures constituted the non-AES group. Blood was collected for the measurement of NSE within 24 hours of hemodynamic stabilization. The median NSE values of both groups were compared by using the Mann-Whitney U test. All statistical analyses were performed with SPSS version 12 for Windows.

RESULTS

In the study period, 30 patients were enrolled. Glasgow Coma Scale mostly decreased in the AES group by about 40% in the level ≤8. All patients in the AES group suffered from status epilepticus and 46.67% of them had body temperature >40℃. Most of the cases in the AES group had longer duration of stay in the hospital. The median serum NSE level in the AES group was 157.86 ng/mL, and this value was significantly higher than that of the non-AES group (10.96 ng/mL; P<0.05).

CONCLUSION

AES cases showed higher levels of serum NSE. These results indicate that serum NSE is a good indicator of neuronal brain injury.

Effects of andrographolide on postoperative cognitive dysfunction and the association with NF-κB/MAPK pathway

The present study investigated the effects of andrographolide on postoperative cognitive dysfunction (POCD) in aged rats to gain insight of the underlying mechanism, which may provide theoretical basis for the clinical application of andrographolide to prevent POCD in older patients. Thirty aged male rats were randomly assigned to 3 groups: Control, model and andrographolide groups. The Morris water maze test was used to examine the spatial memory and learning ability of the rats postoperatively. The histological alterations of neuronal cells in the hippocampus were visualized by H&E staining. The serum levels of neuron-specific enolase (NSE), human soluble protein-100β (S-100β) and the inflammation factors of interluekin (IL)-1β, IL-6 and TNF-α involved in the nuclear factor κB (NF-κB)/mitogen-activated protein kinase (MAPK) signaling pathway were detected by ELISA. The NF-κB/MAPK signaling pathway-associated proteins in rat serum were detected by western blotting. Following andrographolide treatment, the rats significantly gained learning ability after surgery. Is it ameliorated hippocampal neuronal injury in rats following surgery. Andrographolide decreased NSE, S-100β, and the inflammation factors, IL-6, IL-1β and TNF-α in serum. Andrographolide reduced NF-κB/MAPK pathway-associated protein expression. Andrographolide ameliorated POCD in aged rats following surgery. The underlying mechanism may be associated with the downregulation the inflammatory factors and NF-κB/MAPK-associated protein expression.

The role of stump pressure and cerebral oximetry in predicting ischaemic brain damage during carotid endarterectomy

Objective is to compare the predictive value of stump pressure (SP) and cerebral oximetry (rSO2) levels in the evaluation of ischaemic injury of the cerebrum during clamping of the carotid artery (CCA) without temporary shunt (TS). Methods We included 84 patients with an asymptomatic stenosis (>70%) of the internal carotid artery (ICA) who underwent carotid endarterectomy (CEA) under GA. Cerebral ischaemic tolerance (CIT) was determined on the basis of SP, rSO2 and ∆rSO2 (↓rSO2 from baseline) during CCA. The levels of S100 protein (S100) and neuron-specific enolase (NSE) were measured on each stage of the study. MRI was performed for all patients. Results There were no perioperative strokes and myocardial infarctions during the study. Temporary shutdown of blood flow in CAs during CEA is accompanied by a significant elevation of S100, NSE concentration with their subsequent restoration (three days after surgery). ROC analysis showed that none of the methods for CIT assessment (SP, rSO2 and ∆rSO2) was a valuable predictor of cerebral damage during CEA. Conclusion SP with a threshold value of ≤40 mmHg has an average quality of prediction (AUC = 63). ∆rSO2 of ≥20% and a threshold value of rSO2 ≤ 40% have an unsatisfactory quality of prediction (AUC < 60).

Effect of Memantine on Serum Levels of Neuron-Specific Enolase and on the Glasgow Coma Scale in Patients With Moderate Traumatic Brain Injury

Traumatic brain injury (TBI) is a major cause of disability and death globally. Despite significant progress in neuromonitoring and neuroprotection, pharmacological interventions have failed to generate favorable results. We examined the effect of memantine on serum levels of neuron-specific enolase (NSE), a marker of neuronal damage, and the Glasgow Coma Scale (GCS) in patients with moderate TBI. Patients were randomly assigned to the control group (who received standard TBI management) and the treatment group (who, alongside their standard management, received enteral memantine 30 mg twice daily for 7 days). Patients' clinical data, GCS, findings of head computed tomography, and serum NSE levels were collected during the study. Forty-one patients were randomized into the control and treatment groups, 19 and 22 patients respectively. Baseline characteristics and serum NSE levels were not significantly different between the 2 groups. The mean serum NSE levels for the memantine and the control groups on day 3 were 7.95 ± 2.86 and 12.33 ± 7.09 ng/mL, respectively (P = .05), and on day 7 were 5.03 ± 3.25 and 10.04 ± 5.72 ng/mL, respectively (P = .003). The mean GCS on day 3 was 12.3 ± 2.0 and 10.9 ± 1.9 in the memantine and control groups, respectively (P = .03). Serum NSE levels and GCS changes were negatively correlated (r = -0.368, P = .02). Patients with moderate TBI who received memantine had significantly reduced serum NSE levels by day 7 and marked improvement in their GCS scores on day 3 of the study.

Update on Inflammatory Biomarkers and Treatments in Ischemic Stroke

After an acute ischemic stroke (AIS), inflammatory processes are able to concomitantly induce both beneficial and detrimental effects. In this narrative review, we updated evidence on the inflammatory pathways and mediators that are investigated as promising therapeutic targets. We searched for papers on PubMed and MEDLINE up to August 2016. The terms searched alone or in combination were: ischemic stroke, inflammation, oxidative stress, ischemia reperfusion, innate immunity, adaptive immunity, autoimmunity. Inflammation in AIS is characterized by a storm of cytokines, chemokines, and Damage-Associated Molecular Patterns (DAMPs) released by several cells contributing to exacerbate the tissue injury both in the acute and reparative phases. Interestingly, many biomarkers have been studied, but none of these reflected the complexity of systemic immune response. Reperfusion therapies showed a good efficacy in the recovery after an AIS. New therapies appear promising both in pre-clinical and clinical studies, but still need more detailed studies to be translated in the ordinary clinical practice. In spite of clinical progresses, no beneficial long-term interventions targeting inflammation are currently available. Our knowledge about cells, biomarkers, and inflammatory markers is growing and is hoped to better evaluate the impact of new treatments, such as monoclonal antibodies and cell-based therapies.

Biomarkers for acute diagnosis and management of stroke in neurointensive care units

The effectiveness of current management of critically ill stroke patients depends on rapid assessment of the type of stroke, ischemic or hemorrhagic, and on a patient's general clinical status. Thrombolytic therapy with recombinant tissue plasminogen activator (r-tPA) is the only effective treatment for ischemic stroke approved by the Food and Drug Administration (FDA), whereas no treatment has been shown to be effective for hemorrhagic stroke. Furthermore, a narrow therapeutic window and fear of precipitating intracranial hemorrhage by administering r-tPA cause many clinicians to avoid using this treatment. Thus, rapid and objective assessments of stroke type at admission would increase the number of patients with ischemic stroke receiving r-tPA treatment and thereby, improve outcome for many additional stroke patients. Considerable literature suggests that brain-specific protein biomarkers of glial [i.e. S100 calcium-binding protein B (S100B), glial fibrillary acidic protein (GFAP)] and neuronal cells [e.g., ubiquitin C-terminal hydrolase-L1 (UCH-L1), neuron-specific enolase (NSE), αII-spectrin breakdown products SBDP120, SBDP145, and SBDP150, myelin basic protein (MBP), neurofilament light chain (NF-L), tau protein, visinin-like protein-1 (VLP 1), NR2 peptide] injury that could be detected in the cerebrospinal fluid (CSF) and peripheral blood might provide valuable and timely diagnostic information for stroke necessary to make prompt management and decisions, especially when the time of stroke onset cannot be determined. This information could include injury severity, prognosis of short-term and long-term outcomes, and discrimination of ischemic or hemorrhagic stroke. This chapter reviews the current status of the development of biomarker-based diagnosis of stroke and its potential application to improve stroke care.

Incidence and Clinical Outcome of Patients with Hypertensive Acute Ischemic Stroke: An Update from Tertiary Care Center of Central India

Introduction:

We evaluated the incidence and clinical outcome of patients with hypertensive acute ischemic stroke (AIS) admitted to a tertiary care center in Central India. In addition, we examined the status of stroke biomarkers namely neuron-specific enolase (NSE), glial specific protein (S-100ββ), and inter-α-trypsin inhibitor heavy chain 4(ITIH4) in the serum of patients suffering from AIS with hypertension (HTN) and without HTN.

Methods:

A total of 104 patients with AIS were enrolled for the study. Clinical outcome and stroke biomarker levels were evaluated in them at the time of hospital discharge and then followed at 12 months and 18 months after hospital discharge.

Results:

HTN is a major risk factor associated with 67%(70.104) of patients with AIS. Multivariate analysis suggests higher odds of 4.088(95%Cl, 0.721–23.179) and 2.437(95%Cl, 0.721–23.179) for 12 and 18 months outcome in patients with AIS and HTN, respectively. Serum NSE and S-100ββ decreased at the time of discharge as compared to admission level in improved patients suffering from AIS with or without HTN, whereas levels of ITIH4 peptides 2 and 7 increased at the time of discharge (compared to its admission level) only in improved patients with AIS regardless of HTN or non-HTN condition.

Conclusion:

HTN is one of the major risk factors associated with higher risk of AIS as well as long-term unfavourable outcome after AIS in Central India region. NSE, S-100ββ, and ITIH4 were found to be independent predictors of outcome in patients with AIS irrespective of HTN and non-HTN condition.

Impact of Admission Time on Treatment and Outcome of Stroke in Patients Admitted to Tertiary Care Hospital: A Pilot Study from Central India

INTRODUCTION

Admission of patients within window period has been linked with efficacy of treatment outcome and recovery. The present study examined the effects of early vs delayed admission on functional outcome of Acute Ischemic Stroke (AIS) as well as added value of stroke markers in such patients admitted to a tertiary care hospital in Central India.

MATERIALS AND METHODS

Hundred and four patients admitted to Neurology department of Central India Institute of Medical Sciences were grouped as early referrals (within 24 hour admission) and late referrals (after 24 hour admission) based on onset of symptoms and time of admission. Baseline data, throm bolysis eligibility, hospital and long term outcomes were determined in early and later referrals. Stroke markers NSE, S-100 ββ and ITIH4 peptides were also screened in patients who were further categorized as improved and expired /dependent during hospital outcome. Outcome of death /dependency in both groups was analysed using multivariate regression analysis. Kaplan-Meier analysis was performed to determine the rate of stroke-mortality in hospital and over 12 and 15 month period.

RESULTS

Hospital outcome indicated higher percentage (90%) of improved cases in early referrals as opposed to 79% observed in late referrals. Similarly, the ratio of dependency was slighter higher in late referrals (18%) as compared to early referral (6%) cases. The long term outcome at 12 and 18 months showed more or less similar ratio of death/dependency in early (23%, 9%) and late referrals (32%,24%) respectively. Multivariate analysis revealed no significant impact of risk confounders at long term and short term outcome in both groups. Analysis of stroke marker revealed better prognosis with significant association between ITIH4 peptides and NSE & S-100 ββ level with level of improvement in early referrals.

CONCLUSION

Early admission of AIS patients is associated with better hospital outcome. However admission time has no major impact on long term outcome in AIS patients. Moreover, stroke markers such ITIH4, can be used as a predictor of stroke outcome and may have prognostic importance in AIS cases in future.

Elevated Serum Levels of NSE and S-100β Correlate with Increased Risk of Acute Cerebral Infarction in Asian Populations

BACKGROUND

We investigated the clinical value of serum levels of neuron-specific enolase (NSE) and human soluble protein-100β (S-100β) in acute cerebral infarction (ACI) patients.

MATERIAL AND METHODS

A literature search of electronic databases identified relevant case-control studies that examined the correlations between NSE and S-100β serum levels, and ACI. The retrieved studies were screened based on our strict inclusion and exclusion criteria, and high-quality studies were subsequently selected for meta-analysis. STATA software (Version 12.0, Stata Corporation, College Station, TX, USA) was utilized for statistical analysis.

RESULTS

A total of 13 case-control studies, containing 911 ACI patients and 686 healthy controls, were enrolled in this meta-analysis. The results of the meta-analysis showed that serum levels of NSE and S-100β in ACI patients were significantly higher than the control group. Subgroup analysis based on ethnicity revealed that the serum levels of NSE and S-100β in ACI patients were significantly higher than the control group in Asian population. In Caucasian population, the serum levels of NSE in case group was significantly higher than the control group, but no significant differences in serum levels of S-100β were observed between ACI patients and the control group.

CONCLUSIONS

Based on our results, we conclude that serum levels of NSE and S-100β strongly correlate with ACI in Asian population, and may be important clinical markers for diagnosis and treatment of ACI.

Neuron-Specific Enolase as a Biomarker: Biochemical and Clinical Aspects

Neuron-specific enolase (NSE) is known to be a cell specific isoenzyme of the glycolytic enzyme enolase. In vertebrate organisms three isozymes of enolase, expressed by different genes, are present: enolase α is ubiquitous; enolase β is muscle-specific and enolase γ is neuron-specific. The expression of NSE, which occurs as γγ- and αγ-dimer, is a late event in neural differentiation, thus making it a useful index of neural maturation.NSE is a highly specific marker for neurons and peripheral neuroendocrine cells. As a result of the findings of NSE in specific tissues under normal conditions, increased body fluids levels of NSE may occur with malignant proliferation and thus can be of value in diagnosis, staging and treatment of related neuroendocrine tumours (NETs).NSE is currently the most reliable tumour marker in diagnosis, prognosis and follow-up of small cell lung cancer (SCLC), even though increased levels of NSE have been reported also in non-small cell lung cancer (NSCLC). The level of NSE correlates with tumour burden, number of metastatic sites and response to treatment.NSE can be also useful at diagnosis of NETs and gastroenteropancreatic (GEP)-NETs.Raised serum levels of NSE have been found in all stages of neuroblastoma, although the incidence of increased concentration is greater in widespread and metastatic disease. Moreover, NSE determination in cord blood offers an early postnatal possibility of confirming the diagnosis of neuroblastoma in newborns.NSE has been demonstrated to provide quantitative measures of brain damage and/or to improve the diagnosis and the outcome evaluation in ischaemic stroke, intracerebral hemorrhage, seizures, comatose patients after cardiopulmonary resuscitation for cardiac arrest and traumatic brain injury.Increased NSE serum levels have also been found associated with melanoma, seminoma, renal cell carcinoma, Merkel cell tumour, carcinoid tumours, dysgerminomas and immature teratomas, malignant phaechromocytoma, Guillain-Barré syndrome and Creutzfeldt-Jakob disease.