Neuron-specific enolase at admission as a predictor for stroke volume, severity and outcome in ischemic stroke patients: a prognostic biomarker review

An ideal blood biomarker for stroke should provide reliable results, enable fast diagnosis, and be readily accessible for practical use. Neuron-specific enolase (NSE), an enzyme released after neuronal damage, has been studied as a marker for brain injury, including cerebral infarction. However, different methodologies and limited sample sizes have restricted the applicability of any potential findings. This work aims to determine whether NSE levels at Emergency Department (ED) admission correlate with stroke severity, infarcted brain volume, functional outcome, and/or death rates. A systematic literature review was performed using PubMed, Embase, and Scopus databases. Each reviewer independently assessed all published studies identified as potentially relevant. All relevant original observational studies (cohort, case-control, and cross-sectional studies) were included. Eleven studies (1398 patients) met the inclusion criteria. Among these, six studies reported a significant correlation between NSE levels and stroke severity, while only one found no association. Four studies indicated a positive relationship between infarcted brain volume assessed by imaging and NSE levels, in contrast to the findings of only one study. Four studies identified an association related to functional outcome and death rates, while three others did not reach statistical significance in their findings. These data highlight that NSE levels at ED admissions proved to be a promising tool for predicting the outcome of ischemic stroke patients in most studies. However, they presented high discrepancies and low robustness. Therefore, further research is necessary to establish and define the role of NSE in clinical practice.

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.

Association between circulating inflammatory biomarkers and functional outcome or perihaematomal oedema after ICH: a systematic review & meta-analysis

Background

Currently, there are no specific medical treatments for intracerebral haemorrhage (ICH), but the inflammatory response may provide a potential route to treatment. Given the known effects of acute brain injury on peripheral immunity, we hypothesised that inflammatory biomarkers in peripheral blood may be associated with clinical outcome following ICH, as well as perihaematomal oedema (PHO), which is an imaging marker of the neuroinflammatory response.

Methods

We searched OVID Medline and EMBASE on 07 April 2021 for studies of humans with ICH measuring an inflammatory biomarker in peripheral blood and PHO or clinical outcome. Risk of bias was assessed both by using a scale comprising features of the Newcastle-Ottawa Assessment Scale, STROBE-ME and REMARK guidelines, and for studies included in meta-analysis, also by the QUIPS tool.We used random effects meta-analysis to pool standardised mean differences (SMD) if ≥1 study quantified the association between identical biomarkers and measures of PHO or functional outcome.

Results

Of 8,615 publications, 16 examined associations between 21 inflammatory biomarkers and PHO (n=1,299 participants), and 93 studies examined associations between ≥1 biomarker and clinical outcome (n=17,702 participants). Overall, 20 studies of nine biomarkers (n=3,199) met criteria for meta-analysis of associations between inflammatory biomarkers and clinical outcome. Death or dependency (modified Rankin Scale (mRS) 3‒6) 90 days after ICH was associated with higher levels of fibrinogen (SMD 0.32; 95%CI [0.04, 0.61]; p=0.025), and high mobility group box protein 1 (HMGB1) (SMD 1.67; 95%CI [0.05, 3.30]; p=0.04). Higher WBC was associated with death or dependency at 90 days (pooled SMD 0.27; 95% CI [0.11, 0.44]; p=0.001; but the association was no longer significant when the analysis was restricted to studies with a low risk of bias (pooled SMD 0.22; 95% CI -0.04-0.48). Higher CRP seemed to be associated with death or dependency at 90 days (pooled SMD 0.80; 95% CI [0.44, 1.17]; p<0.0001) but this association was no longer significant when adjusted OR were pooled (OR 0.99 (95% CI 0.98-1.01)).

Conclusions

Higher circulating levels of, fibrinogen and HMGB1 are associated with poorer outcomes after ICH. This study highlights the clinical importance of the inflammatory response to ICH and identifies additional research needs in determining if these associations are mediated via PHO and are potential therapeutic targets.

Registration

PROSPERO ( CRD42019132628; 28/05/2019).

Neurovascular Unit-Derived Extracellular Vesicles: From Their Physiopathological Roles to Their Clinical Applications in Acute Brain Injuries

Extracellular vesicles (EVs) form a heterogeneous group of membrane-enclosed structures secreted by all cell types. EVs export encapsulated materials composed of proteins, lipids, and nucleic acids, making them a key mediator in cell–cell communication. In the context of the neurovascular unit (NVU), a tightly interacting multicellular brain complex, EVs play a role in intercellular communication and in maintaining NVU functionality. In addition, NVU-derived EVs can also impact peripheral tissues by crossing the blood–brain barrier (BBB) to reach the blood stream. As such, EVs have been shown to be involved in the physiopathology of numerous neurological diseases. The presence of NVU-released EVs in the systemic circulation offers an opportunity to discover new diagnostic and prognostic markers for those diseases. This review outlines the most recent studies reporting the role of NVU-derived EVs in physiological and pathological mechanisms of the NVU, focusing on neuroinflammation and neurodegenerative diseases. Then, the clinical application of EVs-containing molecules as biomarkers in acute brain injuries, such as stroke and traumatic brain injuries (TBI), is discussed.

Fluid biomarkers in stroke: From animal models to clinical care

Stroke is a leading cause of death and disability worldwide. Stroke prevention, early diagnosis, and efficient acute treatment are priorities to successfully impact stroke death and disability. Fluid biomarkers may improve stroke differential diagnostic, patient stratification for acute treatment, and post-stroke individualized rehabilitation. In the present work, we characterized the use of stroke animal models in fluid biomarker research through a systematic review of PubMed and Scopus databases, followed by a literature review on the translation to the human stroke care setting and future perspectives in the field. We found increasing numbers of publications but with limited translation to the clinic. Animal studies are very heterogeneous, do not account for several human features present in stroke, and, importantly, only a minority of such studies used human cohorts to validate biomarker findings. Clinical studies have found appealing candidates, both protein and circulating nucleic acids, to contribute to a more personalized stroke care pathway. Still, brain tissue complexity and the fact that different brain pathologies share lesion biomarkers make this task challenging due to biomarker low specificity. Moreover, the study design and lack of validation cohorts may have precluded a formal integration of biomarkers in different steps of stroke diagnosis and treatment. To overcome such issues, recent pivotal studies on biomarker dynamics in individual patients are providing added value to diagnosis and anticipating patients' early prognosis. Presently, the most consistent protein biomarkers for stroke diagnosis and short- and long-term prognosis are associated with tissue damage at neuronal (TAU), axonal (NFL), or astroglial (GFAP and S100β) levels. Most promising nucleic acids are microRNAs (miR), due to their stability in plasma and ease of access. Still, clinical validation and standardized quantitation place them a step behind compared protein as stroke biomarkers. Ultimately, the definition of clinically relevant biomarker panels and optimization of fast and sensitive biomarker measurements in the blood, together with their combination with clinical and neuroimaging data, will pave the way toward personalized stroke care.

Basal IL-6 and S100b levels are associated with infarct volume

OBJECTIVES

The study of biomarkers related to the infarct volume of acute ischaemic stroke (AIS) is a valuable clinical strategy. We conducted a prospective study to evaluate the relationship between a wide panel of biomarkers involved in different biochemical pathways and lesion volume.

MATERIALS & METHODS

We studied 332 patients with AIS. Infarct volume was calculated from diffusion weighted imaging (DWI). Blood samples were drawn within 24 h of symptom onset to test a panel of biomarkers that included high-sensitivity C-reactive protein (hs-CRP), IL-6, neuron-specific enolase (NSE), N-terminal pro-B-type natriuretic peptide (NT-ProBNP), S100b, troponin and IL-10.

RESULTS

The median lesion volume was 2.5 cc (IQR: 0.6-15.3). Patients with previous atrial fibrillation, cardioembolic aetiology and total anterior circulation infarct TACI classification had higher lesion volumes than those without them. Patients with previous recent TIA had smaller ischaemic lesions than those without it. Age and NIHSS were significantly correlated with lesion volume. In a linear regression analysis adjusted by aetiology, S100b and IL-6 emerged as the only biomarkers independently associated with infarct volume. In contrast, previous recent TIA and small-vessel disease were inversely related to infarct volume.

CONCLUSIONS

The correlation between the two blood marker levels and ischaemic lesion volume would support the use of these biomarkers as a surrogate endpoint in AIS, especially in centres without DWI 24/7 but these could not substitute basic neuroimaging. Our findings should be further explored in larger, preferably multicentre studies.

Prognostic molecular markers for motor recovery in acute hemorrhagic stroke: A systematic review

BACKGROUND AND AIMS

Molecular biomarkers are associated with poor prognosis in ischemic stroke individuals. However, it might not be generalizable to post-acute hemorrhagic stroke since the underlying mechanisms of this brain damage differ from those found in ischemic stroke. The main purpose of this review was to synthesize the potential predictive molecular biomarkers for motor recovery following acute hemorrhagic stroke.

MATERIALS AND METHODS

An electronic search was conducted by 2 independent reviewers in the following databases: PubMed (Medline), EMBASE, Web of Science, and CINAHL. We included studies that addressed the following: collected blood, urine, or cerebrospinal fluid samples within 72 h after hemorrhagic stroke and that reported the prognostic association with functional motor recovery for each molecular biomarker. Screening of titles, abstracts, and full texts and data extraction were undertaken independently by pairs of reviewers.

RESULTS

Twelve thousand, five hundred and sixty-four studies were identified and 218 were considered eligible. Finally, we included 70 studies, with 96 biomarkers analyzed, of which 61 were considered as independent prognostic biomarkers, and 10 presented controversial results.

CONCLUSION

This systematic review shows that motor functional recovery can be predicted by 61 independent prognostic molecular biomarkers assessed in the acute phase after a hemorrhagic stroke.

Validity of neuron-specific enolase as a prognostic tool in acute ischemic stroke in adults at Suez Canal University Hospital

Background

Biological markers of acute nerve cell damage can assist in the outcome of acute ischemic stroke, such as neuron-specific enolase (NSE) that have been tested for association with initial severity of stroke, extent of infarction, and functional outcome.

Objective

To determine short-term prognostic value of the biochemical marker neuron-specific enolase (NSE) in acute ischemic stroke.

Methods

A cohort study carried out on 37 patients with acute ischemic stroke. Data were gathered in a prepared data sheet. Initial serum NSE level was measured to the patients in the Emergency department within 6 h of the onset of stroke and another measurement after 48 h. National Institute of Health Stroke Scale (NIHSS) was held to the patients at presentation and after 28 days of stroke to determine short-term morbidity and mortality.

Results

Out of the 37 patients, 31 patients survived (no-death group) and 6 patients died (death group). The mean serum level of neuron-specific enolase at presentation and after 48 h was significantly higher in the death group than in the no-death group. There was a statistically significant positive correlation between neuron-specific enolase (NSE) serum level and clinical severity of stroke (NIHSS) among the patients at presentation (r = 0.737, p = 0.000).

Conclusion

Neuron-specific enolase (NSE) can be applied as single independent marker for prediction of mortality and short-term morbidity in ischemic stroke patients.

The presence of leukoaraiosis enhances the association between sTWEAK and hemorrhagic transformation

Objective

To investigate whether elevated serum levels of sTWEAK (soluble tumor necrosis factor‐like inducer of apoptosis) might be involved in a higher frequency of symptomatic hemorrhagic transformation (HT) through the presence of leukoaraiosis (LA) in patients with acute ischemic stroke (IS) undergoing reperfusion therapies.

Methods

This is a retrospective observational study. The primary endpoint was to study the sTWEAK‐LA‐HT relationship by comparing results with biomarkers associated to HT and evaluating functional outcome at 3‐months. Clinical factors, neuroimaging variables and biomarkers associated to inflammation, endothelial/atrial dysfunction or blood‐brain barrier damage were also investigated.

Results

We enrolled 875 patients (mean age 72.3 ± 12.2 years; 46.0% women); 710 individuals underwent intravenous thrombolysis, 87 endovascular therapy and 78 both. HT incidence was 32%; LA presence was 75.4%. Patients with poor functional outcome at 3‐months showed higher sTWEAK levels at admission (9844.2 [7460.4–12,542.0] vs. 2717.3 [1489.7–5852.3] pg/mL, P < 0.0001). By means of logistic regression models, PDGF‐CC and sTWEAK were associated with mechanisms linked simultaneously to HT and LA. Serum sTWEAK levels at admission ≥6700 pg/mL were associated with an odds ratio of 13 for poor outcome at 3‐months (OR: 13.6; CI 95%: 8.2–22.6, P < 0.0001).

Conclusions

Higher sTWEAK levels are independently associated with HT and poor functional outcome in patients with IS undergoing reperfusion therapies through the presence of LA. sTWEAK could become a therapeutic target to reduce HT incidence in patients with IS.

Red blood cell distribution width is associated with neuronal damage in acute ischemic stroke

Elevated red blood cell distribution width (RDW) has been found to be associated with the occurrence of ischemic stroke. However, there is no defined relationship between RDW and neuronal damage in acute ischemic stroke (AIS). This study was designed to determine the relationship between RDW and neuronal damage in AIS patients. A total of 442 consecutive AIS patients from January 2018 to June 2019 were evaluated for neuronal damage, which was estimated by serum neuron-specific enolase (NSE) levels. Red blood cell distribution width-standard deviation (RDW-SD), a parameter that reflects the heterogeneity of red blood cell volume, was also assessed. We evaluated the association between the RDW-SD and serum NSE level through multivariate-adjusted linear regression analysis. Both the serum NSE level and the incidence of high NSE increased according to the increased RDW-SD tertile in AIS patients (p<0.01). There was a positive correlation between RDW-SD and serum NSE levels (r=0.275, 95% CI: 0.187-0.359, p<0.001). The beta coefficients (95% CI) between RDW-SD and serum NSE levels were 0.32 (0.21-0.42, p<0.001) and 0.26 (0.15-0.38, p<0.001), respectively, in AIS patients before and after adjusting for potential confounders. In conclusion, we found a significant positive association between RDW-SD and neuronal damage in AIS patients.

[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.

Brain Injury Biomarker Behavior in Spontaneous Intracerebral Hemorrhage

BACKGROUND

S100B and neuron-specific enolase (NSE) have been widely studied in diverse neurocritical pathologies, being recognized as the most promising biomarkers for brain injury assessment. However, their role in intracerebral hemorrhage (ICH) has not been widely analyzed.

METHODS

This was an observational prospective cohort study of patients with ICH admitted to a neurocritical care unit. Blood samples were collected on admission and at 24 hours, 48 hours, and 72 hours. Patient outcomes were assessed at 6 months after the event.

RESULTS

Thirty-six patients with ICH were included in the study. The mortality rate was 36%. Nonsurvivors had higher S100B values than survivors at admission, 24 hours, and 48 hours (P < 0.05). Likewise, S100B levels were higher in patients with poor outcomes (modified Rankin Scale [mRS] score >4) compared with those with good outcome (mRS score ≤3) in the 24-hour, 48-hour, and 72-hour samples. Receiver operating characteristic (ROC) curve analysis showed that S100B at admission, 24 hours, and 48 hours can discriminate between patients who survive and those who die as a consequence of ICH. The 48-hour sample (area under the ROC curve, 0.817; P = 0.003) reached the best values for sensitivity (75%) and specificity (80%); cutoff, 0.250 μg/L. For 6-month functional outcome, S100B protein could differentiate between groups at 24, 48, and 72 hours. The S100B 24-hour sample had the best values for sensitivity (82.6%) and specificity (72.7%), with a cutoff of 0.202 μg/L. We found no clear relationship between NSE values and clinical characteristics.

CONCLUSIONS

S100B protein acts as early predictor of mortality and functional outcome in patients with ICH. This biomarker measurement can provide additional information beyond clinical and radiologic findings to guide physicians in the management of these patients.

Neuron-Specific Enolase and Matrix Metalloproteinase 9 Signal Perioperative Silent Brain Infarction During or After Transcatheter Aortic Valve Implantation

Magnetic resonance imaging (MRI) studies have consistently identified a high incidence of silent brain infarction (SBI) after cardiac intervention. The frequent occurrence, objective measurement and clinical sequelae of SBI have seen interest in their detection for both research and clinical purposes. However, MRI is expensive, time-consuming, unsafe in acutely-ill patients, and not always available, limiting its use as a routine screening tool. For this purpose, a blood biomarker of SBI would be the "Holy Grail." By performing targeted profiling of serologic biomarkers this study aimed to assess their potential as screening tools for perioperative SBI. This is a nested case-control study of 20 prospectively recruited patients undergoing transcatheter aortic valve implantation under general anesthesia. Clinical and diffusion-weighted MRI assessments were performed at baseline and on day 3 postprocedure to identify the presence (cases) or absence (controls) of new SBI. Blood was collected at baseline and 24, 48, and 72 hours postprocedure and analyzed for S100 calcium-binding protein B, neuron specific enolase (NSE), matrix metalloproteinase 9 (MMP 9), and glial fibrillary acidic protein. Best-fit polynomial curves using a smoothing model were generated for each biomarker and inferential testing at a predefined 24-hour postprocedure timepoint detected a significant difference for MMP 9 (72,435; SEM: 25,030; p = 0.027). Longitudinal regression revealed a statistically significant case-control difference for both NSE (mean: 10,747; SEM: 3,114) and MMP 9 (63,842; SEM: 16,173). In conclusion, NSE and MMP 9 are present in higher levels following SBI and warrant further investigation for their utility as screening tools.

CXCR7+ and CXCR4+ stem cells and neuron specific enolase in acute ischemic stroke patients

Stroke causes an efflux of various groups of progenitor/stem cells from bone marrow to bloodstream and a rise in neuron specific enolase (NSE) serum concentrations. The aim of this study was to identify activity of chosen stem/progenitor cells during first 7 days after stroke through correlations between these cells levels and NSE values. Additional goal was to confirm the role of NSE as a prognostic marker of ischemic stroke. Venous blood was collected repeatedly from 67 acute ischemic stroke patients and 15 control subjects, in order to assess NSE with ELISA, and CD45^-CD34 ⁺ CD271+, CD45^-CD34 + CXCR4+, CD45^-CD34 + CXCR7+ and CD45^-CD34 ⁺ CD133 + stem/progenitor cells by means of flow cytometry. Patients underwent repeated assessment with the National Ischemic Stroke Scale and modified Rankin Scale. Ischemic lesion volumes were assessed twice by MRI-DWI (day 1 and 5 ± 2). NSE correlated negatively with MFI levels of the CD45^-CD34 + CXCR7+ cells, and percentage levels of the CD45^-CD34 ⁺ and CD45^-CD34 + CXCR4+ cells. NSE concentrations were significantly higher in patients compared to control subjects. NSE on day 2 positively correlated with lesion volume on both MRI. NSE on day 2 and 6-7 correlated positively with initial NIHSS scores, and on day 1 with mRS score on day 9. In conclusion, in this study NSE indicated some activity of the CD45^-CD34 + CXCR7+, CD45^-CD34 ⁺ and CD45^-CD34 + CXCR4+ stem/progenitor cells in the first 7 days after ischemic stroke. Additionally, this study supports the thesis that NSE might be a valuable prognostic marker in acute ischemic stroke.

Reframing the Biological Basis of Neuroprotection Using Functional Genomics: Differentially Weighted, Time-Dependent Multifactor Pathogenesis of Human Ischemic Brain Damage

Background: Neuroprotection studies are generally unable to demonstrate efficacy in humans. Our specific hypothesis is that multiple pathophysiologic pathways, of variable importance, contribute to ischemic brain damage. As a corollary to this, we discuss the broad hypothesis that a multifaceted approach will improve the probability of efficacious neuroprotection. But to properly test this hypothesis the nature and importance of the multiple contributing pathways needs elucidation. Our aim is to demonstrate, using functional genomics, in human cardiac surgery procedures associated with cerebral ischemia, that the pathogenesis of perioperative human ischemic brain damage involves the function of multiple variably weighted proteins involving several pathways. We then use these data and literature to develop a proposal for rational design of human neuroprotection protocols.

Methods: Ninety-four patients undergoing deep hypothermic circulatory arrest (DHCA) and/or aortic valve replacement surgery had brain damage biomarkers, S100β and neurofilament H (NFH), assessed at baseline, 1 and 24 h post-cardiopulmonary bypass (CPB) with analysis for association with 92 single nucleotide polymorphisms (SNPs) (selected by co-author WAK) related to important proteins involved in pathogenesis of cerebral ischemia.

Results: At the nominal significance level of 0.05, changes in S100β and in NFH at 1 and 24 h post-CPB were associated with multiple SNPs involving several prospectively determined pathophysiologic pathways, but were not individually significant after multiple comparison adjustments. Variable weights for the several evaluated SNPs are apparent on regression analysis and, notably, are dissimilar related to the two biomarkers and over time post CPB. Based on our step-wise regression model, at 1 h post-CPB, SOD2, SUMO4, and GP6 are related to relative change of NFH while TNF, CAPN10, NPPB, and SERPINE1 are related to the relative change of S100B. At 24 h post-CPB, ADRA2A, SELE, and BAX are related to the relative change of NFH while SLC4A7, HSPA1B, and FGA are related to S100B.

Conclusions: In support of the proposed hypothesis, association SNP data suggest function of specific disparate proteins, as reflected by genetic variation, may be more important than others with variation at different post-insult times after human brain ischemia. Such information may support rational design of post-insult time-sensitive multifaceted neuroprotective therapies.

Neuron-specific enolase levels as a marker for possible neuronal damage in idiopathic intracranial hypertension

Although formerly considered as a "benign" disease, the presence of some important problems such as vision loss, resistance to appropriate medical treatment and relapses suggests that neuronal damage might play a role in the pathophysiology of IIH. In order to demonstrate possible neuronal damage/dysfunction participating in IIH pathophysiology, we aimed to investigate the relationship between serum neuron-specific enolase (NSE) levels and clinical features in patients with idiopathic intracranial hypertension (IIH). Thirty-six patients with IIH, diagnosed according to the revised criteria, and 40 age, gender and body mass index-matched healthy controls were enrolled in this study after their consent. Serum samples were evaluated for NSE via enzyme-linked immunosorbent assay method. NSE levels were higher in the IIH group (23.7 ± 14.53 ng/ml) compared to the control group (22.7 ± 13.11 ng/ml), but the difference was not statistically significant (p = 0.824). There were also no statistically significant differences in NSE levels in IIH patients regarding the presence of visual loss, relapse, oligoclonal bands and papilledema. We could not demonstrate any correlations between NSE levels and age, body mass index, cerebrospinal fluid opening pressure and disease duration. The present study is the first to analyze NSE levels in IIH patients and showed no significant difference between patients and controls, and also between different clinical subgroups of IIH patients.

A review of the clinical utility of serum S100B protein levels in the assessment of traumatic brain injury

Background

In order to improve injury assessment of brain injuries, protein markers of pathophysiological processes and tissue fate have been introduced in the clinic. The most studied protein “biomarker” of cerebral damage in traumatic brain injury (TBI) is the protein S100B. The aim of this narrative review is to thoroughly analyze the properties and capabilities of this biomarker with focus on clinical utility in the assessment of patients suffering from TBI.

Results

S100B has successfully been implemented in the clinic regionally (1) to screen mild TBI patients evaluating the need to perform a head computerized tomography, (2) to predict outcome in moderate-to-severe TBI patients, (3) to detect secondary injury development in brain-injured patients and (4) to evaluate treatment efficacy. The potential opportunities and pitfalls of S100B in the different areas usually refer to its specificity and sensitivity to detect and assess intracranial injury.

Conclusion

Given some shortcomings that should be realized, S100B can be used as a versatile screening, monitoring and prediction tool in the management of TBI patients.

A review of the clinical utility of serum S100B protein levels in the assessment of traumatic brain injury

BACKGROUND

In order to improve injury assessment of brain injuries, protein markers of pathophysiological processes and tissue fate have been introduced in the clinic. The most studied protein "biomarker" of cerebral damage in traumatic brain injury (TBI) is the protein S100B. The aim of this narrative review is to thoroughly analyze the properties and capabilities of this biomarker with focus on clinical utility in the assessment of patients suffering from TBI.

RESULTS

S100B has successfully been implemented in the clinic regionally (1) to screen mild TBI patients evaluating the need to perform a head computerized tomography, (2) to predict outcome in moderate-to-severe TBI patients, (3) to detect secondary injury development in brain-injured patients and (4) to evaluate treatment efficacy. The potential opportunities and pitfalls of S100B in the different areas usually refer to its specificity and sensitivity to detect and assess intracranial injury.

CONCLUSION

Given some shortcomings that should be realized, S100B can be used as a versatile screening, monitoring and prediction tool in the management of TBI patients.

The Relationship Between Serum Neuron-Specific Enolase Levels and Severity of Bleeding and Functional Outcomes in Patients With Nontraumatic Subarachnoid Hemorrhage

BACKGROUND

The value of neuron-specific enolase (NSE) in predicting clinical outcomes has been investigated in a variety of neurological disorders.

OBJECTIVE

To investigate the associations of serum NSE with severity of bleeding and functional outcomes in patients with subarachnoid hemorrhage (SAH).

METHODS

We retrospectively reviewed the records of patients with SAH from June 2008 to June 2012. The severity of SAH bleeding at admission was measured radiographically with the Fisher scale and clinically with the Glasgow Coma Scale, Hunt and Hess grade, and World Federation of Neurologic Surgeons scale. Outcomes were assessed with the modified Rankin Scale at discharge.

RESULTS

We identified 309 patients with nontraumatic SAH, and 71 had NSE testing. Median age was 54 years (range, 23-87 years), and 44% were male. In multivariable analysis, increased NSE was associated with a poorer Hunt and Hess grade (P = .003), World Federation of Neurologic Surgeons scale score (P < .001), and Glasgow Coma Scale score (P = .003) and worse outcomes (modified Rankin Scale at discharge; P = .001). There was no significant association between NSE level and Fisher grade (P = .81) in multivariable analysis.

CONCLUSION

We found a significant association between higher NSE levels and poorer clinical presentations and worse outcomes. Although it is still early for any relevant clinical conclusions, our results suggest that NSE holds promise as a tool for screening patients at increased risk of poor outcomes after SAH.

Distinct inflammatory responses differentiate cerebral infarct from transient ischaemic attack

We previously reported on a 26-year-old patient who presented early during a large and eventually fatal cerebral infarct. Microarray analysis of blood samples from this patient demonstrated initially up-regulated and subsequently down-regulated Granzyme B (GzmB) expression, along with progressive up-regulation of genes for S100 calcium binding protein A12 (S100A12) and matrix metalloproteinase 9 (MMP-9). To confirm these findings, we investigated these parameters in patients with suspected stroke presenting within 6h of symptom onset to a single centre. Blood samples were taken at enrolment, then 1h, 3h and 24h post-enrolment for the examination of cellular, protein and genetic changes. Patients with subsequently confirmed ischaemic (n=18) or haemorrhagic stroke (n=11) showed increased intracellular concentrations of GzmB in all cell populations investigated (CD8⁺, CD8^- and Natural Killer [NK] cells). Infarct patients, however, demonstrated significantly reduced GzmB gene expression and increased circulating MMP-9 and S100A12 levels in contrast to transient ischaemic attack (TIA) patients or healthy controls. Furthermore, a pronounced neutrophilia was noted in the infarct and haemorrhage groups, while TIA patients (n=9) reflected healthy controls (n=10). These findings suggest a spectrum of immune response during stroke. TIA showed few immunological changes in comparison to infarct and haemorrhage, which demonstrated inhibition of GzmB production and a rise in neutrophil numbers and neutrophil-associated mediators. This implies a greater role of the innate immune system. These markers may provide novel targets for inhibition and reduction of secondary injury.

Effect of Tempol on Cerebral Resuscitation Caused by Asphyxia-Induced Cardiac Arrest

BACKGROUND

This study was conducted to investigate the effect and mechanism of the nitrogen oxide 4-hydroxy- 2,2,6,6-tetramethylpiperidine (Tempol) on cerebral resuscitation caused by asphyxia-induced cardiac arrest.

METHODS

Airway occlusion-induced asphyxia at the end of expiration was used to establish the rat cerebral ischaemia-hypoxia injury model. A total of 90 adult male Sprague-Dawley rats were randomly divided into the three groups. The Tempol and conventional cardiopulmonary resuscitation (CPR) groups were further divided into four subgroups according to different time points.

RESULTS

After cerebral ischaemia, independent heart rate following asphyxia appeared earlier, and the success rate of primary recovery and the neurological function score of rats were higher in the Tempol group than in the conventional CPR group. The serum neuron-specific enolase (NSE) levels in the Tempol and conventional CPR groups were significantly higher within 6 to 48 h than that in the blank control group. The serum NSE level was significantly lower in the Tempol group than the conventional CPR group.

CONCLUSIONS

After global cerebral ischaemia-hypoxia, the antioxidant Tempol improved cerebral resuscitation by reducing oxidative stress injuries and post-CPR cerebral damage. The NSE level can be used as an early detection index in the diagnosis of global cerebral ischaemia-hypoxia injuries.

KEY WORDS

Cerebral ischemia; Neuron-specific enolase; Rats; Tempol.

Worse Neurological State During Acute Ischemic Stroke is Associated with a Decrease in Serum Albumin Levels

High serum albumin levels during ischemic stroke (IS) decrease the risk of a poor outcome. This study aimed to determine whether serum albumin levels within the first days after IS correlate with radiological and biochemical markers of brain tissue damage. Fifty-six IS patients were enrolled into the study. Neurological examinations were based on the National Institute of Health Stroke Scale. Serum albumin levels and S100BB were evaluated using commercially available ELISA kits. The albumin decrease index (ADI) was calculated as the difference between serum albumin levels measured on days 1 and 10 of IS. All parameters were estimated on the 1st, 3rd, 5th, and 10th days of IS, and the volume of ischemic focus was measured on the 10th day. Mean serum albumin levels were decreased during acute IS. There were correlations between the ADI and mean S100BB serum levels (r = 0.36, p < 0.05), the volume of ischemic focus (r = 0.39, p < 0.05), and the patients’ neurological state when measured on day 10 of IS (r = 0.59, p < 0.001). A decrease in serum albumin levels during the acute phase of IS corresponds to a worse neurological state as a result of a large ischemic focus with intense catabolic processes.

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.

Monitoring biomarkers of cellular injury and death in acute brain injury

BACKGROUND

Molecular biomarkers have revolutionalized diagnosis and treatment of many diseases, such as troponin use in myocardial infarction. Urgent need for high-fidelity biomarkers in neurocritical care has resulted in numerous studies reporting potential candidate biomarkers.

METHODS

We performed an electronic literature search and systematic review of English language articles on cellular/molecular biomarkers associated with outcome and with disease-specific secondary complications in adult patients with acute ischemic stroke (AIS), intracerebral hemorrhage (ICH), subarachnoid hemorrhage (SAH), traumatic brain injury (TBI), and post-cardiac arrest hypoxic ischemic encephalopathic injuries (HIE).

RESULTS

A total of 135 articles were included. Though a wide variety of potential biomarkers have been identified, only neuron-specific enolase has been validated in large cohorts and shows 100% specificity for poor outcome prediction in HIE patients not treated with therapeutic hypothermia. There are many promising candidate blood and CSF biomarkers in SAH, AIS, ICH, and TBI, but none yet meets criteria for routine clinical use.

CONCLUSION

Current studies vary significantly in patient selection, biosample collection/processing, and biomarker measurement protocols, thereby limiting the generalizability of overall results. Future large prospective studies with standardized treatment, biosample collection, and biomarker measurement and validation protocols are necessary to identify high-fidelity biomarkers in neurocritical care.

Neuron-Specific Enolase, S100 Calcium-Binding Protein B, and Heat Shock Protein 70 Levels in Patients With Intracranial Hemorrhage

The authors evaluated neuron-specific enolase (NSE), S100 calcium-binding protein B (S100B), and heat shock protein 70 (HSP 70) levels and their relationships with in-hospital mortality, Glasgow Coma Scale (GCS) scores, and National Institute of Health Stroke Scale (NIHSS) scores. In total, 35 patients older than 18 years were presented to our emergency department and were diagnosed with non-traumatic intracranial hemorrhage (ICH) and 32 healthy controls were included. Blood samples were drawn on days 0 and 5. S100 calcium-binding protein B and HSP levels were significantly higher in patients than in controls on days 0 and 5. Neuron-specific enolase levels were higher in patients than in controls on day 0, but there was no significant difference on day 5. S100 calcium-binding protein B was negatively correlated with GCS, whereas it was positively correlated with NIHSS and bleeding volume. There was also a negative correlation between NSE and GCS, but it was not statistically significant. In addition, no significant correlation was found in terms of bleeding volume or NIHSS. Heat shock protein 70 was negatively correlated with GCS and positively correlated with bleeding volume and NIHSS, but these results were not statistically significant. S100 calcium-binding protein B and HSP 70 levels were significantly higher in those who died compared with survivors. The areas under the curve of S100 B, NSE, and HSP 70 for mortality were 0.635, 0.477, and 0.770, respectively. Neuron-specific enolase, S100B, and HSP 70 levels are simple, inexpensive, and objective measures in cases of ICH. These tests can be used to support an assessment for screening ICH patients with clinical scoring systems, such as GCS and NIHSS.

Serum neuron specific enolase level as a predictor of prognosis in acute ischemic stroke patients after intravenous thrombolysis

OBJECTIVE

Serum neuron specific enolase (NSE) concentrations are significantly correlated with stroke severity and clinical outcome in ischemic stroke patients. We aimed to determine whether the serum levels of neuron specific enolase in acute ischemic stroke (AIS) patients after intravenous thrombolysis are associated with stroke severity, and indicative of favorable outcome.

METHODS

We prospectively analyzed the serum neuron specific enolase levels with for 67 subjects with AIS patients treated with intravenous recombinant tissue type plasminogen activator (rtPA) within 4.5h from symptom onset. Neurologic deficit was assessed by the National Institutes of Health Stroke Scale. Clinical outcome was assessed after 90days according to the modified Rankin Scale.

RESULTS

Neuron specific enolase levels correlated with National Institutes of Health Stroke Scale score 24h after rtPA bolus (R=0.342, p=0.005). Regarding the 67 included patients, 32 (47.8%) reached favorable outcome. They had a lower NIHSS score on admission (p=0.000) and at 24h after rtPA bolus (p=0.000), and had lower levels of neuron specific enolase (p=0.006). But only NIHSS score at 24h after rtPA bolus rather than neuron specific enolase level was an independent predictor for favorable outcome.

CONCLUSION

We found that after treatment with intravenous rtPA therapy, lower serum neuron specific enolase levels were associated with favorable outcome, which may be confounded by the link to NIHSS score.

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.

Optimal therapeutic dose and time window of picroside II in cerebral ischemic injury

A preliminary study from our research group showed that picroside II inhibited neuronal apoptosis in ischemic penumbra, reduced ischemic volume, and improved neurobehavioral function in rats with cerebral ischemia. The aim of the present study was to validate the neuroprotective effects of picroside II and optimize its therapeutic time window and dose in a rat model of cerebral ischemia. We found that picroside II inhibited cell apoptosis and reduced the expression of neuron-specific enolase, a marker of neuronal damage, in rats after cerebral ischemic injury. The optimal treatment time after ischemic injury and dose were determined, respectively, as follows: (1) 2.0 hours and 10 mg/kg according to the results of toluidine blue staining; (2) 1.5 hours and 10 mg/kg according to early apoptotic ratio by flow cytometry; (3) 2.0 hours and 10 mg/kg according to immunohistochemical and western blot analysis; and (4) 1.5 hours and 10 mg/kg according to reverse transcription polymerase chain reaction. The present findings suggest that an intraperitoneal injection of 10 mg/kg picroside II 1.5-2.0 hours after cerebral ischemic injury in rats is the optimal dose and time for therapeutic benefit.

Endotoxin-induced lung alveolar cell injury causes brain cell damage

Sepsis is the most common cause of acute respiratory distress syndrome, a severe lung inflammatory disorder with an elevated morbidity and mortality. Sepsis and acute respiratory distress syndrome involve the release of inflammatory mediators to the systemic circulation, propagating the cellular and molecular response and affecting distal organs, including the brain. Since it has been reported that sepsis and acute respiratory distress syndrome contribute to brain dysfunction, we investigated the brain-lung crosstalk using a combined experimental in vitro airway epithelial and brain cell injury model. Conditioned medium collected from an in vitro lipopolysaccharide-induced airway epithelial cell injury model using human A549 alveolar cells was subsequently added at increasing concentrations (no conditioned, 2%, 5%, 10%, 15%, 25%, and 50%) to a rat mixed brain cell culture containing both astrocytes and neurons. Samples from culture media and cells from mixed brain cultures were collected before treatment, and at 6 and 24 h for analysis. Conditioned medium at 15% significantly increased apoptosis in brain cell cultures 24 h after treatment, whereas 25% and 50% significantly increased both necrosis and apoptosis. Levels of brain damage markers S100 calcium binding protein B and neuron-specific enolase, interleukin-6, macrophage inflammatory protein-2, as well as matrix metalloproteinase-9 increased significantly after treating brain cells with ≥2% conditioned medium. Our findings demonstrated that human epithelial pulmonary cells stimulated with bacterial lipopolysaccharide release inflammatory mediators that are able to induce a translational clinically relevant and harmful response in brain cells. These results support a brain-lung crosstalk during sepsis and sepsis-induced acute respiratory distress syndrome.

Neuron specific enolase and c-reactive protein levels in stroke and its subtypes: correlation with degree of disability

Stroke is an emergency which threatens life and third leading cause of death and long term disability in developed countries. The use of biomarkers in diagnosing stroke and assessing prognosis is an emerging and rapidly evolving field. The study aimed to investigate the predictive value of biochemical marker of brain damage neuron-specific enolase (NSE) and systemic inflammatory marker C-reactive protein (CRP) with respect to degree of disability at the time of admission and short term in stroke patients. We investigated 120 patients with cerebrovascular stroke who were admitted within 72 h of onset of stroke in the Department of Neurology at Sri Aurobindo Institute of Medical Sciences, Indore, India. NSE and CRP were analyzed by solid enzyme linked immunosorbent assay using analyzer and micro plate reader from Biorad 680. In all patients, the neurological status was evaluated by a standardized neurological examination and the National Institutes of Health Stroke Scale on admission and on day 7. Serum NSE and CRP concentration were found significantly increased in acute stroke cases as compared to control in present study (<0.05 and <0.001 respectively). The maximum serum NSE and CRP levels within 72 h of admission were significantly higher in patients with greater degree of disability at the time of admission. Both biomarkers were found significantly correlated with neurological disability and short term outcome. Our study showed that serum biomarkers NSE and CRP have high predictive value for determining severity and early neurobehavioral outcome after acute stroke.

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

CONTEXT

The use of biomarkers to predict stroke prognosis is gaining particular attention nowadays. Neuron specific enolase (NSE), which is a dimeric isoenzyme of the glycolytic enzyme enolase and is found mainly in the neurons is one such biomarker.

AIMS

This study was carried out on patients of acute ischemic stroke with the aims to determine the correlation between NSE levels on the day of admission with infarct volume, stroke severity, and functional neurological outcome on day 30.

MATERIALS AND METHODS

Seventy five patients of acute ischemic stroke admitted in the Department of Medicine were included in the study. Levels of NSE were determined on day 1 using the human NSE ELISA kit (Alpha Diagnostic International Texas 78244, USA). Volume of infarct was measured by computed tomography (CT) scan using the preinstalled software Syngo (version A40A) of Siemen's medical solutions (Forchheim, Germany). Stroke severity at admission was assessed using Glasgow coma scale (GCS) and functional neurological outcome was assessed using modified Rankin scale (mRS) on day 30.

STATISTICAL ANALYSIS USED

Statistical analysis was performed using the SPSS software for windows version 15.0 (SPSS).

RESULTS

A positive correlation was found between concentration of NSE on day 1 and infarct volume determined by CT scan (r = 0.955, P < 0.001). A strong negative correlation was found between GCS at presentation and concentration of NSE on day 1 (r = -0.806, P < 0.001). There was a positive correlation between NSE levels at day 1 and functional neurological outcome assessed by mRS at day 30 (r = 0.744, P < 0.001).

CONCLUSIONS

Serum levels of NSE in first few days of ischemic stroke can serve as a useful marker to predict stroke severity and early functional outcome. However, larger studies with serial estimation of NSE are needed to establish these observations more firmly.

Identification of novel biomarkers of brain damage in patients with hemorrhagic stroke by integrating bioinformatics and mass spectrometry-based proteomics

Hemorrhagic stroke (HS) is a significant cause of mortality that requires rapid diagnosis and prompt medical attention. A time-efficient diagnostic test to assist in the early classification of patients with stroke would be of great value. The aims here were to (a) select "brain-specific" proteins using a bioinformatics approach, (b) develop selected reaction monitoring (SRM) assays for candidate proteins, and (c) quantify these proteins in cerebrospinal fluid (CSF). "The Human Protein Atlas" and the "Peptide Atlas" were used to select proteins specifically and abundantly expressed in brain tissue, excluding high-abundance plasma proteins. Protein extracts from brain tissue were used for SRM assay development of proteins of interest. The levels of 68 "brain-specific" proteins were measured by SRM in 36 age-matched patients, including individuals with HS (n = 15), ischemic stroke (n = 11), and controls (n = 10). Additionally, S100B was measured using an electrochemoluminometric immunoassay. CSF levels of S100B and eight of the "brain-specific" proteins (NSE, GFAP, α-Inx, MBP, MT3, NFM, β-Syn, and γ-Syn) were increased in a subset of samples from HS patients, especially in those individuals with intraventricular hemorrhage and poor outcome. Seven of these proteins (S100B, NSE, GFAP, α-Inx, MBP, NFM, and β-Syn) showed significant differences between patients with and without brain hemorrhage. Novel biomarkers of brain injury (α-Inx, NFM, and β-Syn) were identified in the CSF of patients with HS. Investigating the role of these proteins in blood with more sensitive methods is warranted.

Prognostic value of neuron specific enolase and IL-10 in ischemic stroke and its correlation with degree of neurological deficit

BACKGROUND

The blood-brain barrier is compromised in stroke patients. The release of neuro-biochemical protein markers, such as Neuron Specific Enolase (NSE) into the circulation may allow the pathophysiology and prognosis of patients with cerebrovascular diseases to be evaluated further.

METHOD

Present study aimed to investigate the predictive value of NSE and Interleukin-10 (IL-10) with respect to early neurobehavioral outcome which evaluated by National Institute of Health Stroke Scale (NIHSS). We investigated 100 patients of ischemic stroke and blood samples were taken within first 72 h of stroke onset. NSE and IL-10 were analyzed by commercially available ELISA kits. The neurological status was evaluated by a standardized NIHSS at the time of admission.

RESULTS

NSE was significantly increased (17.95±4.54 vs 7.48±1.51 {ng/ml} p≤0.05) and IL-10 significantly decreased (11.79±2.77 vs 15.72±2.69 {pg/ml} p≤0.05) in patients when compared with controls. NSE also significantly (r=0.8, p≤0.001) correlated with degree of neurological deficit but IL-10 level in serum did not show any significant correlation with NIHSS score at the time of admission.

CONCLUSIONS

Serum concentrations of NSE and IL-10 have a high predictive value for early neurobehavioral outcome after acute stroke.

Interrupted intracarotid artery cold saline infusion as an alternative method for neuroprotection after ischemic stroke

Object

Intracarotid artery cold saline infusion (ICSI) is an effective method for protecting brain tissue, but its use is limited because of undesirable secondary effects, such as severe decreases in hematocrit levels, as well as its relatively brief duration. In this study, the authors describe and investigate the effects of a novel ICSI pattern (interrupted ICSI) relative to the traditional method (uninterrupted ICSI).

Methods

Ischemic strokes were induced in 85 male Sprague-Dawley rats by occluding the middle cerebral artery for 3 hours using an intraluminal filament. Uninterrupted infusion groups received an infusion at 15 ml/hour for 30 minutes continuously. The same infusion speed was used in the interrupted infusion groups, but the whole duration was divided into trisections, and there was a 20-minute interval without infusion between sections. Forty-eight hours after reperfusion, H & E and silver nitrate staining were utilized for morphological assessment. Infarct sizes and brain water contents were determined using H & E staining and the dry-wet weight method, respectively. Levels of neuron-specific enolase (NSE), S100β protein, and matrix metalloproteinase 9 (MMP-9) in the serum were determined using enzyme-linked immunosorbent assay. Neurological deficits were also evaluated.

Results

Histology showed that interrupted ICSI did not affect neurons or fibers in rat brains, which suggests that this method is safe for brain tissues with ischemia. The duration of hypothermia induced by interrupted ICSI was longer than that induced via the traditional method, and the decrease in hematocrit levels was less pronounced. There were no differences in infarct size or brain water content between uninterrupted and interrupted ICSI groups, but neuron-specific enolase and matrix metalloproteinase 9 serum levels were more reduced after interrupted ICSI than after the traditional method.

Conclusions

Interrupted ICSI is a safe method. Compared with traditional ICSI, the interrupted method has a longer duration of hypothermia and less effect on hematocrit and offers more potentially improved neuroprotection, thereby making it more attractive as an infusion technique in the clinic.

Sex differences in brain proteomes of neuron-specific STAT3-null mice after cerebral ischemia/reperfusion

Signal transduction and activator of transcription-3 (STAT3) plays an important role in neuronal survival, regeneration and repair after brain injury. We previously demonstrated that STAT3 is activated in brain after cerebral ischemia specifically in neurons. The effect was sex-specific and modulated by sex steroids, with higher activation in females than males. In the current study, we used a proteomics approach to identify downstream proteins affected by ischemia in male and female wild-type (WT) and neuron-specific STAT3 knockout (KO) mice. We established four comparison groups based on the transgenic condition and the hemisphere analyzed, respectively. Moreover, the sexual variable was taken into account and male and female animals were analyzed independently. Results support a role for STAT3 in metabolic, synaptic, structural and transcriptional responses to cerebral ischemia, indeed the adaptive response to ischemia/reperfusion injury is delayed in neuronal-specific STAT3 KO mice. The differences observed between males and females emphasize the importance of sex-specific neuronal survival and repair mechanisms, especially those involving antioxidant and energy-related activities, often caused by sex hormones.

Early biomarkers of clinical-diffusion mismatch in acute ischemic stroke

BACKGROUND AND PURPOSE

Clinical-diffusion mismatch (CDM; National Institutes of Health Stroke Scale score≥8 and diffusion-weighted imaging lesion volume<25 mL) has been suggested as a surrogate of ischemic brain at risk of infarction and might be used to recognize salvageable ischemic tissue. Our aim was to identify early biomarkers associated with the presence of CDM.

METHODS

We prospectively evaluated CDM in 226 patients (71.6±11.1 years, 58% men) with hemispheric ischemic stroke within 12 hours from symptom onset (median, 3.6 hours). Diffusion-weighted MRI lesion volume was measured by manual segmentation method. Serum levels of glutamate, aspartate, interleukin-10, tumor necrosis factor-α, interleukin-6, S100β, neuron-specific enolase, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, active matrix metalloproteinase-9, and cellular fibronectin were determined by immunoassay or high-performance liquid chromatography techniques in blood samples obtained at admission.

RESULTS

CDM was found in 61 patients (26.9%). Patients with CDM had higher serum levels of interleukin-10, tumor necrosis factor-α, and glutamate and lower serum levels of neuron-specific enolase, interleukin-6, and active matrix metalloproteinase-9 (all P<0.0001). Binary logistic regression showed that tumor necrosis factor-α≥21 pg/mL (OR, 21), glutamate≥230 μmol/L (OR, 27), neuron-specific enolase≥23 ng/mL (OR, 0.05), interleukin-6≥10 pg/mL (OR, 0.06), and active matrix metalloproteinase-9≥21 ng/mL (OR, 0.28) were independent molecular predictors of CDM after adjustment for covariates. The association of interleukin-10≥23 pg/mL and glutamate≥230 μmol/L levels predicted CDM with a sensitivity of 96% and a specificity of 98%.

CONCLUSIONS

High levels of interleukin-10, tumor necrosis factor-α, and glutamate as well as low levels of neuron-specific enolase, interleukin-6, and active matrix metalloproteinase-9 are associated with CDM.

Genomic biomarkers and cellular pathways of ischemic stroke by RNA gene expression profiling

OBJECTIVE

The objective of this study was to provide insight into the molecular mechanisms of acute ischemic cerebrovascular syndrome (AICS) through gene expression profiling and pathway analysis.

METHODS

Peripheral whole blood samples were collected from 39 MRI-diagnosed patients with AICS and 25 nonstroke control subjects ≥ 18 years of age. Total RNA was extracted from whole blood stabilized in Paxgene RNA tubes, amplified, and hybridized to Illumina HumanRef-8v2 bead chips. Gene expression was compared in a univariate manner between stroke patients and control subjects using t test in GeneSpring. The significant genes were tested in a logistic regression model controlling for age, hypertension, and dyslipidemia. Inflation of type 1 error was corrected by Bonferroni and Ingenuity Systems Pathway analysis was performed. Validation was performed by QRT-PCR using Taqman gene expression assays.

RESULTS

A 9-gene profile was identified in the whole blood of ischemic stroke patients using gene expression profiling. Five of these 9 genes were identified in a previously published expression profiling study of stroke and are therefore likely biomarkers of stroke. Pathway analysis revealed toll-like receptor signaling as a highly significant canonical pathway present in the peripheral whole blood of patients with AICS.

CONCLUSIONS

Our study highlights the relevance of the innate immune system through toll-like receptor signaling as a mediator of response to ischemic stroke and supports the claim that gene expression profiling can be used to identify biomarkers of ischemic stroke. Further studies are needed to validate and refine these biomarkers for their diagnostic potential.