Association of Serial Biochemical Markers With Acute Ischemic Stroke

Differential Proteomics for Distinguishing Ischemic Stroke from Controls: a Pilot Study of the SpecTRA Project

A diagnostic blood test for stroke is desirable but will likely require multiple proteins rather than a single “troponin.” Validating large protein panels requires large patient numbers. Mass spectrometry (MS) is a cost-effective tool for this task. We compared differences in the abundance of 147 protein markers to distinguish 20 acute cerebrovascular syndrome (ACVS) patients who presented to the Emergency Department of one urban hospital within < 24 h from onset) and from 20 control patients who were enrolled via an outpatient neurology clinic. We targeted proteins from the stroke literature plus cardiovascular markers previously studied in our lab. One hundred forty-one proteins were quantified using MS, 8 were quantified using antibody protein enrichment with MS, and 32 were measured using ELISA, with some proteins measured by multiple techniques. Thirty proteins (4 by ELISA and 26 by the MS techniques) were differentially abundant between mimic and stroke after adjusting for age in robust regression analyses (FDR < 0.20). A logistic regression model using the first two principal components of the proteins significantly improved discrimination between strokes and controls compared to a model based on age alone (p < 0.001, cross-validated AUC 0.93 vs. 0.78). Significant proteins included markers of inflammation (47%), coagulation (40%), atrial fibrillation (7%), neurovascular unit injury (3%), and other (3%). These results suggest the potential value of plasma proteins as biomarkers for ACVS diagnosis and the role of plasma-based MS in this area.

Serum Levels of S100b and NSE Proteins in Patients with Non-Transfusion-Dependent Thalassemia as Biomarkers of Brain Ischemia and Cerebral Vasculopathy

Patients with non-transfusion-dependent thalassemia (NTDT) are at risk of developing brain ischemia. Transcranial Doppler (TCD) has been established as a useful screening tool of cerebrovascular disease in patients with sickle cell disease. Proteins neuron specific enolase (NSE) and S100B are biomarkers that reflect CNS injury. The purpose of this study is to evaluate cerebral vessel vasculopathy and brain damage in NTDT patients using non-invasive methods as TCD and measurement serum levels of NSE and S100B. We included in our study 30 patients with NTDT, aged between 8 and 62 years old (mean: 29.4, median: 32) who presented in our Unit for regular follow-up. We performed in all patients a non-imaging TCD examination and have measured serum S100, NSE and lactate dehydrogenase (LDH) levels. We investigated the possible correlation between TCD results and S100B, NSE and LDH levels as well as between NSE-LDH and S100B-LDH levels by regression analysis. We found a statistically significant relationship for both NSE, S100B with LDH. We also found a statistically significant relationship for S100B and time-averaged mean velocity (TAMV)/peak velocity of left middle cerebral artery (MCA), NSE and pulsatility index (PI)/resistive index (RI) of the left posterior cerebral artery (PCA). TCD results correlated with biomarkers for brain ischemia. This finding enhances the role of TCD as a screening tool for brain ischemia in patients with NTDT.

Serum neuron specific enolase may be a marker to predict the severity and outcome of cerebral venous thrombosis

The objective is to explore the effective of baseline serum neuron specific enolase (NSE) on predicting the severity and outcome in patients with cerebral venous thrombosis (CVT). A total of 156 patients confirmed as CVT in Xuanwu Hospital were enrolled in this retrospective study from March 2011 through September 2016. The severity was evaluated with the National Institutes of Health Stroke Score (NIHSS), intracranial pressure (ICP), and CVT-related complications; the outcome was evaluated by modified Rankin Scale (mRS); the relationship between baseline serum NSE and mRS was analyzed with receiver operating characteristic curve (ROC), logistic regression analysis, and Kaplan-Meier curves. Baseline level of serum NSE was positively associated with baseline NIHSS (r = 0.322, p < 0.001). Among which, patients with high level of serum NSE were also noticed with cerebral venous infarction (p < 0.001), intracranial hemorrhage (p < 0.001), seizure (p = 0.035). Meanwhile, patients in NSE ≥ 15.05 ng/mL group vs. NSE < 15.05 ng/mL group had large mRS scores (≥ 3) at discharge (adjusted OR: 5.40, 95% CI 1.27-22.91; p = 0.022) and higher percentage of mRS scores ≥ 3 during 40 months of outpatient follow-up (log-rank p < 0.001). Baseline level of serum NSE is positively associated with the severity of CVT. Presumably NSE may be a potential predictor for the clinical outcome of CVT.

Prospective of ischemic stroke biomarkers

Methods currently used in brain vascular disorder diagnostics are neither fast enough nor clear-out; thus, there exists a necessity of finding new types of testing which could enlarge and complete the actual panel of diagnostics or be an alternative to current methods. The discovery of sensitive and specific biomarkers of ischemic brain stroke will improve the effects of treatment and will help to assess the progress or complications of the disease. The relevant diagnosis of ischemic stroke (IS) within the first 4.5 hours after the initial symptoms allows for the initiation of treatment with recombinant tissue plasminogen activators which limits the magnitude of negative changes in the brain and which enhance the final effectiveness of therapy. The potential biomarkers which are under investigation are substances involved in the processes of coagulation and fibrinolysis, and are of molecules released from damaged vascular endothelial cells and from nerves and cardiac tissue. The analyzed substances are typical of oxidative stress, apoptosis, excitotoxicity and damage of the blood brain barrier.

Neural autoantibodies in patients with neurological symptoms and histories of chemical/mold exposures

A number of studies have linked exposures to industrial and household chemicals and biological toxins to increased risk of autoimmunity in general and elevated levels of autoantibodies to neural antigens specifically. Elevated neural autoantibodies are biomarkers for many diseases such as multiple sclerosis and Parkinson's disease. Our study reports levels of six types of neural autoantibodies in a group of 24 toxicant-exposed patients. The patients were exposed to a variety of toxicants including contaminated drinking water (four patients), building water/mold damage (eight patients), pesticides (four patients), and other assorted toxic chemicals (eight patients). Levels of all six neural autoantibodies were significantly elevated in most patients and in the patient group at large, with mean antibody levels for the 24 chemically exposed patients (relative to a healthy control population), in descending order: 475% for tau proteins, 391% for microtubule associated proteins-2, 334% for neurofilament proteins (NFP), 302% for myelin basic protein, 299% for glial fibrillary acidic proteins, and 225% for tubulin. Tau protein autoantibodies were significantly elevated in the patient groups with peripheral neuropathy, muscle and joint pain, asthma, and chemical sensitivity. Autoantibodies to tubulin were significantly higher in the chemical sensitivity and asthma patients, autoantibodies to NFP were significantly higher in the patients with sleep apnea, whereas S-100B autoantibodies were significantly increased in patients with muscle/joint pain, asthma, and apnea/insomnia. In patients exposed to environmental toxicants, measurements of autoantibodies may be useful for prevention, diagnosis, and treatment. This study adds to the scientific literature the ability of a broad spectrum of environmental triggers adversely affecting the nervous system through the process of autoimmunity, which may explain the increasing incidence of neurodegenerative diseases.

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.

White Matter Injury after Intracerebral Hemorrhage: Pathophysiology and Therapeutic Strategies

Intracerebral hemorrhage (ICH) accounts for 10%–30% of all types of stroke. Bleeding within the brain parenchyma causes gray matter (GM) destruction as well as proximal or distal white matter (WM) injury (WMI) due to complex pathophysiological mechanisms. Because WM has a distinct cellular architecture, blood supply pattern and corresponding function, and its response to stroke may vary from that of GM, a better understanding of the characteristics of WMI following ICH is essential and may shed new light on treatment options. Current evidence using histological, radiological and chemical biomarkers clearly confirms the spatio-temporal distribution of WMI post- ICH. Although certain types of pathological damage such as inflammatory, oxidative and neuro-excitotoxic injury to WM have been identified, the exact molecular mechanisms remain unclear. In this review article, we briefly describe the constitution and physiological function of brain WM, summarize evidence regarding WMI, and focus on the underlying pathophysiological mechanisms and therapeutic strategies.

The role of magnesium sulfate in the intensive care unit

Magnesium (Mg) has been developed as a drug with various clinical uses. Mg is a key cation in physiological processes, and the homeostasis of this cation is crucial for the normal function of body organs. Magnesium sulfate (MgSO4) is a mineral pharmaceutical preparation of magnesium that is used as a neuroprotective agent. One rationale for the frequent use of MgSO4 in critical care is the high incidence of hypomagnesaemia in intensive care unit (ICU) patients. Correction of hypomagnesaemia along with the neuroprotective properties of MgSO4 has generated a wide application for MgSO4 in ICU.

Molecular Links and Biomarkers of Stroke, Vascular Dementia, and Alzheimer's Disease

Stroke is a very common neurological disease, and it occurs when the blood supply to part of the brain is interrupted and the subsequent shortage of oxygen and nutrients causes damage to the brain tissue. Stroke is the second leading cause of death and the third leading cause of disability-adjusted life years. The occurrence of stroke increases with age, but anyone at any age can suffer a stroke. Stroke can be broadly classified in two major clinical types: ischemic stroke (IS) and hemorrhagic stroke. Research also revealed that stroke, vascular dementia (VaD), and Alzheimer's disease (AD) increase with a number of modifiable factors, and most strokes can be prevented and/or controlled through pharmacological or surgical interventions and lifestyle changes. The pathophysiology of stroke, VaD, and AD is complex, and recent molecular and postmortem brain studies have revealed that multiple cellular changes have been implicated, including inflammatory responses, microRNA alterations, and marked changes in brain proteins. These molecular and cellular changes provide new information for developing therapeutic strategies for stroke and related vascular disorders treatment. IS is the major risk factor for VaD and AD. This chapter summarizes the (1) links among stroke-VaD-AD; (2) updates the latest developments of research in identifying protein biomarkers in peripheral and central nervous system tissues; and (3) critically evaluates miRNA profile and function in human blood samples, animal, and postmortem brains.

Glial biomarkers in human central nervous system disease

There is a growing understanding that aberrant GLIA function is an underlying factor in psychiatric and neurological disorders. As drug discovery efforts begin to focus on glia-related targets, a key gap in knowledge includes the availability of validated biomarkers to help determine which patients suffer from dysfunction of glial cells or who may best respond by targeting glia-related drug mechanisms. Biomarkers are biological variables with a significant relationship to parameters of disease states and can be used as surrogate markers of disease pathology, progression, and/or responses to drug treatment. For example, imaging studies of the CNS enable localization and characterization of anatomical lesions without the need to isolate tissue for biopsy. Many biomarkers of disease pathology in the CNS involve assays of glial cell function and/or response to injury. Each major glia subtype (oligodendroglia, astroglia and microglia) are connected to a number of important and useful biomarkers. Here, we describe current and emerging glial based biomarker approaches for acute CNS injury and the major categories of chronic nervous system dysfunction including neurodegenerative, neuropsychiatric, neoplastic, and autoimmune disorders of the CNS. These descriptions are highlighted in the context of how biomarkers are employed to better understand the role of glia in human CNS disease and in the development of novel therapeutic treatments. GLIA 2016;64:1755-1771.

Antigen Presentation After Stroke

Stroke induces a local inflammatory reaction and a plethora of innate immune responses in the brain where antigen-presenting cells become prominent. However, to date, it is still unclear whether antigen presentation is relevant to the neuropathological and functional outcome of stroke. Stroke does not trigger overt autoimmune reactions, but neural antigens have been found in lymphoid tissues of patient with stroke and it is unknown whether they promote tolerance or immune reactions that under certain conditions might contribute to the functional worsening observed in some patients. Autoantibodies to neural molecules have also been reported in patients with stroke, but the subclass of antibodies is important for their function, and the contribution of such findings to stroke outcome is not yet clear. Notably, stroke induces immunodepression highlighted by a transient lymphopenia, lymphoid organ atrophy, and monocyte deactivation. While these effects might reduce the chances of autoreactivity, they increase the risk of infection in patients with stroke and most frequently in those with severe stroke. Therefore any potential brain protective effect of stroke-induced immunodepression by attenuating or preventing lymphocyte-mediated brain damage is confounded by stroke severity and an increased incidence of infections. Systemic inflammation due to a number of comorbidities that are frequent in patients with stroke is also associated to a poor outcome. Herein, we review some relevant findings regarding the identification of neural antigens in stroke and discuss their potential contribution to the functional outcome of stroke.

Peripheral biomarkers of stroke: Focus on circulatory microRNAs

Stroke is the second leading cause of death in the world. Stroke occurs when blood flow stops, and that stoppage results in reduced oxygen supply to neurons in the brain. The occurrence of stroke increases with age, but anyone at any age can suffer from stroke. Recent research has implicated multiple cellular changes in stroke patients, including oxidative stress and mitochondrial dysfunction, inflammatory responses, and changes in mRNA and proteins. Recent research has also revealed that stroke is associated with modifiable and non-modifiable risk factors. Stroke can be controlled by modifiable risk factors, including diet, cardiovascular, hypertension, smoking, diabetes, obesity, metabolic syndrome, depression and traumatic brain injury. Stroke is the major risk factor for vascular dementia (VaD) and Alzheimer's disease (AD). The purpose of this article is to review the latest developments in research efforts directed at identifying 1) latest developments in identifying biomarkers in peripheral and central nervous system tissues, 2) changes in microRNAs (miRNAs) in patients with stroke, 3) miRNA profile and function in animal brain, and 4) protein biomarkers in ischemic stroke. This article also reviews research investigating circulatory miRNAs as peripheral biomarkers of stroke.

The determination of copeptin levels helps management decisions among transient ischaemic attack patients

BACKGROUND

Most approaches to transient ischaemic attack (TIA) triage use clinical scores and vascular imaging; however, some biomarkers have been suggested to improve the prognosis of TIA patients.

METHODS

Serum levels of copeptin, adiponectin, neopterin, neuron-specific enolase, high-sensitivity C-reactive protein, IL-6, N-terminal pro-B-type natriuretic peptide, S100β, tumour necrosis factor-alpha and IL-1α as well as clinical characteristics were assessed on consecutive TIA patients during the first 24 h of the onset of symptoms.

RESULTS

Among 237 consecutive TIA patients, 12 patients (5%) had a stroke within 7 days and 15 (6%) within 90 days. Among all candidate biomarkers analysed, only copeptin was significantly increased in patients with stroke recurrence (SR) within 7 days (P = 0.026) but not within 90 days. A cut-off point of 13.8 pmol/l was established with a great predictive negative value (97.4%). Large artery atherosclerosis (LAA) [hazard ratio (HR) 12.7, 95% CI 3.2-50.1, P < 0.001] and copeptin levels ≥13.8 pmol/l (HR 3.9, 95% CI 1.01-14.4, P = 0.039) were independent predictors of SR at the 7-day follow-up. LAA was the only predictor of 90-day SR (HR 7.4, 95% CI 2.5-21.6, P < 0.001). ABCD3I was associated with 7- and 90-day SRs (P = 0.025 and P = 0.034, respectively). The association between copeptin levels and LAA had a diagnostic accuracy of 90.3%.

CONCLUSIONS

Serum copeptin could be an important prognostic biomarker to guide management decisions among TIA patients. Therefore, TIA patients with copeptin levels below 13.8 pmol/l and without LAA have an insignificant risk of 7-day SR and could be managed on an outpatient basis.

Nilotinib Effects in Parkinson's disease and Dementia with Lewy bodies

BACKGROUND

We evaluated the effects of low doses of the tyrosine kinase Abelson (Abl) inhibitor Nilotinib, on safety and pharmacokinetics in Parkinson's disease dementia or dementia with Lewy bodies.

OBJECTIVES

The primary outcomes of this study were safety and tolerability; pharmacokinetics and target engagement were secondary, while clinical outcomes were exploratory.

METHODS

Twelve subjects were randomized into 150 mg (n = 5) or 300 mg (n = 7) groups and received Nilotinib orally every day for 24 weeks.

RESULTS

This study shows that 150 mg and 300 mg doses of Nilotinib appear to be safe and tolerated in subjects with advanced Parkinson's disease. Nilotinib is detectable in the cerebrospinal fluid (CSF) and seems to engage the target Abl. Motor and cognitive outcomes suggest a possible beneficial effect on clinical outcomes. The CSF levels of homovanillic acid are significantly increased between baseline and 24 weeks of treatment. Exploratory CSF biomarkers were measured.

CONCLUSIONS

This small proof-of-concept study lacks a placebo group and participants were not homogenous, resulting in baseline differences between and within groups. This limits the interpretations of the biomarker and clinical data, and any conclusions should be drawn cautiously. Nonetheless, the collective observations suggest that it is warranted to evaluate the safety and efficacy of Nilotinib in larger randomized, double-blind, placebo-controlled trials.

Plasma D-dimer Level, the Promising Prognostic Biomarker for the Acute Cerebral Infarction Patients

BACKGROUND

Despite being an important cause of death and functional disability, acute cerebral infarction (ACI) lacks accurate and easy tools to predict the outcome of patients beyond clinical variables such as age and stroke severity.

METHODS

To investigate if plasma D-dimer level can be used as such a prognostic biomarker for ACI, so as to better guide patients' management, we studied the association between plasma D-dimer and the functional recovery of 1173 ACI patients. The patients were divided into 2 groups according to modified Rankin Scale (mRS) scores or National Institutes of Health Stroke Scale (NIHSS) scores evaluated on the 30th day after onset.

RESULTS

We observed that plasma D-dimer level correlated significantly with the prognosis of ACI evaluated based on both mRS scores (389.68 ± 32.06 µg/L for poor prognosis versus 377.70 ± 32.68 µg/L for good prognosis, P < .001) and NIHSS scores (387.01 ± 30.60 µg/L for poor prognosis versus 375.23 ± 30.66  µg/L for good prognosis, P < .01). Logistic analysis confirmed that higher D-dimer level was a risk factor for poor prognosis (mRS: odds ratio [OR], 1.604; 95% confidence interval [CI], 1.360-1.892; P < .001; NIHSS: OR, 1.733; 95% CI, 1.461-2.056; P < .01), after adjusted for age, gender, hypertension, diabetes, smoking, and hyperlipidemia.

CONCLUSION

Our results show that plasma D-dimer level is a promising prognosis biomarker for ACI.

Apolipoprotein A1-Unique Peptide as a Diagnostic Biomarker for Acute Ischemic Stroke

Clinically-informative biomarkers of ischemic stroke are needed for rapid diagnosis and timely treatment. In the present study, APOA1 unique peptide (APOA1-UP), a novel peptide biomarker, was identified and quantified by multiple reaction monitoring (MRM) using labeled reference peptide (LRP). Serum samples of 94 patients in the ischemic stroke group and 37 patients in the non-stroke group were analyzed for the levels of total APOA1-UP, low density lipoprotein cholesterol (LDL-C), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and total cholesterol (TC). Median ratio of total APOA1-UP/LRP was 2.14 (interquartile range, 0.40) in the non-stroke group and 1.32 (0.44) in the ischemic stroke group (p < 0.0001). The serum level of total APOA1-UP was independently correlated with the presence of ischemic stroke by multivariate logistic regression analysis (p < 0.0001). From the receiver operating characteristic (ROC) curve, the area under the curve (AUC) was 0.9750 and the optimal cutoff value of the serum APOA1-UP level was 1.80, which yielded a sensitivity of 90.63% and a specificity of 97.14%. The diagnostic efficiency of HDL-C was lower, with an AUC of 0.7488. Therefore, the serum level of APOA1-UP is a diagnostic biomarker candidate for ischemic stroke in the early stage.

S100B and Neuron-Specific Enolase as mortality predictors in patients with severe traumatic brain injury

OBJECTIVE

To determine temporal profile and prognostic ability of S100B protein and neuron-specific enolase (NSE) for prediction of short/long-term mortality in patients suffering from severe traumatic brain injury (sTBI).

METHODS

Ninety-nine patients with sTBI were included in the study. Blood samples were drawn on admission and on subsequent 24, 48, 72, and 96 h.

RESULTS

15.2% of patients died in NeuroCritical Care Unit, and 19.2% died within 6 months of the accident. S100B concentrations were significantly higher in patients who died compared to survivors. NSE levels were different between groups just at 48 h. In the survival group, S100B levels decreased from 1st to 5th sample (p < 0.001); NSE just from 1st to 3rd (p < 0.001) and then stabilized. Values of S100B and NSE in non-survival patients did not significantly vary over the four days post sTBI. ROC-analysis showed that all S100B samples were useful tools for predicting mortality, the best the 72 h sample (AUC 0.848 for discharge mortality, 0.855 for six-month mortality). NSE ROC-analysis indicated that just the 48-h sample predicted mortality (AUC 0.733 for discharge mortality, 0.720 for six-month mortality).

CONCLUSION

S100B protein showed higher prognostic capacity than NSE to predict short/long-term mortality in sTBI patients.

The Diagnostic Value of Circulating Brain-specific MicroRNAs for Ischemic Stroke

Objective Circulating microRNAs have been recognized as promising biomarkers for various diseases. The aim of the present study was to explore the potential role of circulating miR-107, miR-128b and miR-153 as non-invasive biomarkers in the diagnosis of ischemia stroke. Methods One hundred and fourteen ischemic stroke patients (61±11.3 years old) and 58 healthy volunteers (56±3.9 years old) matched for age and sex were enrolled in this study. Total RNA was isolated from plasma with TRIzol reagent. The circulating microRNAs levels were measured by quantitative real-time polymerase chain reaction. Results The circulating levels of miR-107, miR-128b and miR-153 significantly increased 2.78-, 2.13- and 1.83-fold in ischemia stroke patients in comparison to the healthy volunteers, respectively. Receiver operating characteristic (ROC) curves were analyzed using the SPSS software program and revealed the areas under the curve for circulating miR-107, miR-128b and miR-153 to be 0.97, 0.903 and 0.893 in ischemia stroke patients in comparison to healthy volunteers, respectively. The levels of circulating miR-107, miR-128b and miR-153 therefore positively correlated with the severity of stroke as defined by NIHSS classes. Conclusion Our results suggest that circulating miR-107, miR-128b and miR-153 might be used as potential novel non-invasive biomarkers for the diagnosis of ischemia stroke. However, future prospective trials in large-sized patient cohorts are needed before drawing any definitive conclusions.

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.

Prognostic value of somatosensory evoked potentials, neuron-specific enolase, and S100 for short-term outcome in ischemic stroke

To predict short-term outcome in acute ischemic stroke, we analyzed somatosensory evoked potentials (SEP) and biochemical parameters [neuron-specific enolase (NSE) and S100 protein] in a prospective study with serial measurement. In 31 patients with 1st middle cerebral artery infarction, serum NSE and S100 protein were measured daily between days 1 and 6 poststroke. The N20 and N70 components of the SEP (SEP20 and SEP70) were determined on days 1 and 6. SEP and biochemical markers in stroke patients were compared with a control group. Short-term outcome was assessed by the modified Rankin Scale (mRS) at days 7-10 and was dichotomized between good (mRS 0-2) and poor (mRS ≥3) outcome. Specificity and positive predictive value (PPV) were high at day 1 for SEP (SEP20: 100% for both; SEP70: 93 and 88%, respectively) compared with lower values for NSE (67 and 50%) and S100 (23 and 57%). In contrast, S100 showed the highest sensitivity at day 1 with 77% compared with a relatively low sensitivity of NSE (31%) and SEP (SEP20: 35%, SEP70: 47%). The biochemical markers showed an improving sensitivity over time with best values (>90%) between days 3 and 4 at the expense of a lower specificity. Specificity and PPV of SEP on day 6 was still 100% with sensitivity increasing up to 53% (SEP20) and 60% (SEP70). SEP could early differentiate between good and poor outcome and reliably predict poor outcome. Since biochemical markers and SEP complement each other in the prognosis of stroke, a combined application of these markers seems promising.

Plasma Biomarkers of Brain Injury as Diagnostic Tools and Outcome Predictors After Extracorporeal Membrane Oxygenation

OBJECTIVE

To determine if elevations in plasma brain injury biomarkers are associated with outcome at hospital discharge in children who require extracorporeal membrane oxygenation.

DESIGN

Prospective observational study.

SETTING

Single tertiary-care academic center.

PARTICIPANTS

Eighty children who underwent extracorporeal membrane oxygenation between June 2010 and December 2013.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We measured six brain injury biomarkers (glial fibrillary acidic protein, monocyte chemoattractant protein 1/chemokine (C-C motif) ligand 2, neuron-specific enolase, S100b, intercellular adhesion molecule-5, and brain-derived neurotrophic factor) daily during extracorporeal membrane oxygenation, using an electrochemiluminescent multiplex assay. We recorded clinical, neuroimaging, and extracorporeal membrane oxygenation course data. We analyzed the association of biomarker concentrations with favorable versus unfavorable outcome at hospital discharge. Favorable outcome was defined as Pediatric Cerebral Performance Category 1, 2, or no change from baseline. Patients had a median age of 3 days (interquartile range, 1 d-10 mo), and 56% were male. Thirty-three of 80 (41%) had unfavorable outcome, and 22 of 70 (31%) had abnormal neuroimaging findings during or after extracorporeal membrane oxygenation. Peak concentrations were significantly higher in patients with unfavorable outcome than in those with favorable outcome for glial fibrillary acidic protein (p = 0.002), monocyte chemoattractant protein 1/chemokine (C-C motif) ligand 2 (p = 0.030), neuron-specific enolase (p = 0.006), and S100b (p = 0.015) and in patients with versus without abnormal neuroimaging findings for glial fibrillary acidic protein (p = 0.001) and intercellular adhesion molecule-5 (p = 0.001). The area under the receiver operator characteristic curve for unfavorable outcome was 0.73 for a noncollinear biomarker combination. After removing collinear biomarkers, the adjusted odds ratios for unfavorable outcome were 2.89 (95% CI, 1.09-7.73) for neuron-specific enolase, using a cutoff of 62.0 ng/mL, and 2.15 (95% CI, 1.06-4.38) for glial fibrillary acidic protein, using a cutoff of 0.46 ng/mL.

CONCLUSIONS

Elevated plasma brain injury biomarker concentrations during the extracorporeal membrane oxygenation course are associated with unfavorable outcome and/or the presence of neuroimaging abnormalities. Combinations of brain-specific proteins increase the sensitivity and specificity for outcome prediction.

Analyzing the Correlation between the Level of Serum Markers and Ischemic Cerebral Vascular Disease by Multiple Parameters

OBJECTIVE

To explore the serum markers associated with ischemic cerebral vascular disease (ICVD) and discuss their diagnostic value.

METHODS

Two hundred and eighty-eight patients with ICVD and one hundred and eighty healthy persons were enrolled as the case group and the control group, respectively. This paper then carried out the univariate and multivariate logistic regression analyses of their respective levels of serum markers, made combined analysis of related factors, and detected the diagnostic value.

RESULTS

Meta-analysis results showed that for ICVD patients the levels of CRP, S-100, TNF-α, HCY, NSE, and IL-6 were higher than those of the healthy persons, while the level of HDL was obviously lower than that of the healthy persons. The multivariate regression analysis indicated that the association between the level of HDL and TNF-α and the occurrence of ICVD was statistically significant (P < 0.05). The area under the curves (AUC) of receiver operating characteristic (ROC) curve of HDL and TNF-α was 0.916, with sensitivity of 90.91% and specificity of 76.47%.

CONCLUSION

HDL has negative correlation with the occurrence of ICVD, while TNF-α was positively correlated with it. The combination test of HDL and TNF-α could raise the accuracy of ICVD diagnosis.

Data for iTRAQ profiling of micro-vesicular plasma specimens: In search of potential prognostic circulatory biomarkers for Lacunar infarction

To discover potential prognostic biomarkers of Lacunar infarction (LACI), here we present quantitative proteomics data of plasma microvesicle-enriched fraction derived by comparative isobaric profiling of three groups of prospectively followed-up LACI patients (LACI – no adverse outcome, LACI –recurrent vascular event and LACI – cognitive decline) and a demographically matched control group. We confidently (unused prot score >3, FDR=1.1%) identified 183 proteins, 43 out of which were significantly regulated (p-value<0.05) in at least one of the three LACI groups in comparison to control group. Bioinformatics analysis and data mining revealed upregulation of brain-specific proteins including myelin basic protein, proteins of coagulation cascade (e.g., fibrinogen alpha chain, fibrinogen beta chain) and focal adhesion (e.g., integrin alpha-IIb, talin-1, and filamin-A) while albumin was downregulated in both groups of patients with adverse outcome. The data of this study are also in line with our previously published article entitled “Discovery of prognostic biomarker candidates of Lacunar infarction by quantitative proteomics of microvesicles enriched plasma” by Datta et al. (2014). The raw data had been deposited to the ProteomeXchange consortium with identifier PXD000748.

To study the correlation of serum S-100 protein level with the severity of stroke and its prognostic implication

Objective:

This study investigated correlation between mortality, stroke subtype and stroke severity with serum S-100 protein level prior to the treatment of the patients admitted to the emergency department and diagnosed with a stroke.

Methods:

Pretreatment sample were collected from the patients (n = 142) to determine S-100 protein level, age and sex-matched healthy individuals (n = 40) served as control. All patients had cranial computerized tomography scan/magnetic resonance imaging in the first 24 h. The neurological evaluation was made with the National Institute of Health Stroke Scale (NIHSS) in the acute stage.

Results:

Compared with controls, S-100 protein level were significantly higher in the stroke groups. In stroke groups, S-100 protein level was more significantly higher in the ischemic group than hemorrhage and transient ischemic attack group and highest in expired patients.

Conclusion:

Serum S-100 protein measurement can be used as an early marker of brain damage. There is a role of S-100 protein as a co-predictor of outcome in patients with acute stroke.

Serum neuron specific enolase – a novel indicator for neuropsychiatric systemic lupus erythematosus?

Objective

Neuropsychiatric (NP) lupus, a common manifestation of systemic lupus erythematosus (SLE), is still insufficiently understood, in part, because of the lack of specific biomarkers. Neuron specific enolase (NSE), an important neuronal glycolytic enzyme, shows increased serum levels following acute brain injury, and decreased serum levels in several chronic disorders of the nervous system, including multi infarct dementia, multiple sclerosis and depression. The aim of the study was to evaluate serum NSE levels in SLE patients with and without nervous system involvement, and in healthy controls, and to assess the correlation of NSE serum levels of patients with neuropsychiatric systemic lupus erythematosus (NPSLE) with clinical parameters.

Methods

The study comprised 47 SLE patients and 28 controls. SLE activity was assessed using the Systemic Lupus Activity Measure (SLAM). A neurologist and a psychiatrist examined all patients. NP involvement was diagnosed according to strict NPSLE criteria proposed by Ainiala and coworkers, as modification to American College of Rheumatology (ACR) nomenclature and case definitions. NSE serum levels were determined by use of an immunoassay.

Results

Mean NSE serum concentrations in patients with NPSLE were significantly lower than in non-NPSLE patients (6.3 ± 2.6 µg/L vs. 9.7 ± 3.3 µg/L, p < 0.01) and in controls (8.8 ± 3.3 µg/L, p < 0.05). There were significant negative correlations between NSE serum levels and SLE activity ( r = −0.42, p < 0.05) and the number of NPSLE manifestations diagnosed (−0.37; p = 0.001).

Conclusion

Decreased serum concentrations of NSE may reflect chronic neuronal damage with declined metabolism of the nervous tissue in patients with NPSLE.

Identification of Site-Specific Stroke Biomarker Candidates by Laser Capture Microdissection and Labeled Reference Peptide

The search to date for accurate protein biomarkers in acute ischemic stroke has taken into consideration the stage and/or the size of infarction, but has not accounted for the site of stroke. In the present study, multiple reaction monitoring using labeled reference peptide (LRP) following laser capture microdissection (LCM) is used to identify site-specific protein biomarker candidates. In middle cerebral artery occlusion (MCAO) rat models, both intact and infarcted brain tissue was collected by LCM, followed by on-film digestion and semi-quantification using triple-quadrupole mass spectrometry. Thirty-four unique peptides were detected for the verification of 12 proteins in both tissue homogenates and LCM-captured samples. Six insoluble proteins, including neurofilament light polypeptide (NEFL), alpha-internexin (INA), microtubule-associated protein 2 (MAP2), myelin basic protein (MBP), myelin proteolipid protein (PLP) and 2′,3′-cyclic-nucleotide 3′-phosphodiesterase (CNP), were found to be site-specific. Soluble proteins, such as neuron-specific enolase (NSE) and ubiquitin carboxyl-terminal hydrolase isozyme L1 (UCHL1), and some insoluble proteins, including neurofilament heavy polypeptide (NEFH), glial fibrillary acidic protein (GFAP), microtubule-associated protein tau (MAPT) and tubulin β-3 chain (TUBB3), were found to be evenly distributed in the brain. Therefore, we conclude that some insoluble protein biomarkers for stroke are site-specific, and would make excellent candidates for the design and analysis of relevant clinical studies in the future.

Current and future bioanalytical approaches for stroke assessment

Efforts are underway to develop novel platforms for stroke diagnosis to meet the criteria for effective treatment within the narrow time window mandated by the FDA-approved therapeutic (<3 h). Blood-based biomarkers could be used for rapid stroke diagnosis and coupled with new analytical tools, could serve as an attractive platform for managing stroke-related diseases. In this review, we will discuss the physiological processes associated with stroke and current diagnostic tools as well as their associated shortcomings. We will then review information on blood-based biomarkers and various detection technologies. In particular, point of care testing that permits small blood volumes required for the analysis and rapid turn-around time measurements of multiple markers will be presented.

Proteomic and biomarker studies and neurological complications of pediatric sickle cell disease

Biomarker analysis and proteomic discovery in pediatric sickle cell disease has the potential to lead to important discoveries and improve care. The aim of this review article is to describe proteomic and biomarker articles involving neurological and developmental complications in this population. A systematic review was conducted to identify relevant research publications. Articles were selected for children under the age of 21 years with the most common subtypes of sickle cell disease. Included articles focused on growth factors (platelet-derived growth factor), intra and extracellular brain proteins (glial fibrillary acidic protein, brain-derived neurotrophic factor), and inflammatory and coagulation markers (interleukin-1β, l-selectin, thrombospondin-1, erythrocyte, and platelet-derived microparticles). Positive findings include increases in plasma brain-derived neurotrophic factor and platelet-derived growth factor with elevated transcranial Dopplers velocities, increases in platelet-derived growth factor isoform AA with overt stroke, and increases in glial fibrillary acidic protein with acute brain injury. These promising potential neuro-biomarkers provide insight into pathophysiologic processes and clinical events, but their clinical utility is yet to be established. Additional proteomics research is needed, including broad-based proteomic discovery of plasma constituents and blood cell proteins, as well as urine and cerebrospinal fluid components, before, during and after neurological and developmental complications.

SUMO proteomics to decipher the SUMO-modified proteome regulated by various diseases

Small ubiquitin-like modifier (SUMO1-3) conjugation is a posttranslational protein modification whereby SUMOs are conjugated to lysine residues of target proteins. SUMO conjugation can alter the activity, stability, and function of target proteins, and thereby modulate almost all major cellular pathways. Many diseases are associated with SUMO conjugation, including heart failure, arthritis, cancer, degenerative diseases, and brain ischemia/stroke. It is, therefore, of major interest to characterize the SUMO-modified proteome regulated by these disorders. SUMO proteomics analysis is hampered by low levels of SUMOylated proteins. Several strategies have, therefore, been developed to enrich SUMOylated proteins from cell/tissue extracts. These include proteomics analysis on cells expressing epitope-tagged SUMO isoforms, use of monoclonal SUMO antibodies for immunoprecipitation and epitope-specific peptides for elution, and affinity purification with peptides containing SUMO interaction motifs to specifically enrich polySUMOylated proteins. Recently, two mouse models were generated and characterized that express tagged SUMO isoforms, and allow purification of SUMOylated proteins from complex organ extracts. Ultimately, these new analytical tools will help to decipher the SUMO-modified proteome regulated by various human diseases, and thereby, identify new targets for preventive and therapeutic purposes.

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.

The Immune Response to Acute Focal Cerebral Ischemia and Associated Post-stroke Immunodepression: A Focused Review

It is currently well established that the immune system is activated in response to transient or focal cerebral ischemia. This acute immune activation occurs in response to damage, and injury, to components of the neurovascular unit and is mediated by the innate and adaptive arms of the immune response. The initial immune activation is rapid, occurs via the innate immune response and leads to inflammation. The inflammatory mediators produced during the innate immune response in turn lead to recruitment of inflammatory cells and the production of more inflammatory mediators that result in activation of the adaptive immune response. Under ideal conditions, this inflammation gives way to tissue repair and attempts at regeneration. However, for reasons that are just being understood, immunosuppression occurs following acute stroke leading to post-stroke immunodepression. This review focuses on the current state of knowledge regarding innate and adaptive immune activation in response to focal cerebral ischemia as well as the immunodepression that can occur following stroke. A better understanding of the intricate and complex events that take place following immune response activation, to acute cerebral ischemia, is imperative for the development of effective novel immunomodulatory therapies for the treatment of acute stroke.

Antigen-specific immune reactions to ischemic stroke

Brain proteins are detected in the cerebrospinal fluid (CSF) and blood of stroke patients and their concentration is related to the extent of brain damage. Antibodies against brain antigens develop after stroke, suggesting a humoral immune response to the brain injury. Furthermore, induced immune tolerance is beneficial in animal models of cerebral ischemia. The presence of circulating T cells sensitized against brain antigens, and antigen presenting cells (APCs) carrying brain antigens in draining lymphoid tissue of stroke patients support the notion that stroke might induce antigen-specific immune responses. After stroke, brain proteins that are normally hidden from the periphery, inflammatory mediators, and danger signals can exit the brain through several efflux routes. They can reach the blood after leaking out of the damaged blood-brain barrier (BBB) or following the drainage of interstitial fluid to the dural venous sinus, or reach the cervical lymph nodes through the nasal lymphatics following CSF drainage along the arachnoid sheaths of nerves across the nasal submucosa. The route and mode of access of brain antigens to lymphoid tissue could influence the type of response. Central and peripheral tolerance prevents autoimmunity, but the actual mechanisms of tolerance to brain antigens released into the periphery in the presence of inflammation, danger signals, and APCs, are not fully characterized. Stroke does not systematically trigger autoimmunity, but under certain circumstances, such as pronounced systemic inflammation or infection, autoreactive T cells could escape the tolerance controls. Further investigation is needed to elucidate whether antigen-specific immune events could underlie neurological complications impairing recovery from stroke.

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

OBJECTIVES

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

DESIGN

Prospective longitudinal cohort study.

SETTING

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

PATIENTS

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

INTERVENTIONS

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

MEASUREMENTS AND MAIN RESULTS

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

CONCLUSIONS

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

Thrombolysis for acute ischaemic stroke

BACKGROUND

Most strokes are due to blockage of an artery in the brain by a blood clot. Prompt treatment with thrombolytic drugs can restore blood flow before major brain damage has occurred and improve recovery after stroke in some people. Thrombolytic drugs, however, can also cause serious bleeding in the brain, which can be fatal. One drug, recombinant tissue plasminogen activator (rt-PA), is licensed for use in selected patients within 4.5 hours of stroke in Europe and within three hours in the USA. There is an upper age limit of 80 years in some countries, and a limitation to mainly non-severe stroke in others. Forty per cent more data are available since this review was last updated in 2009.

OBJECTIVES

To determine whether, and in what circumstances, thrombolytic therapy might be an effective and safe treatment for acute ischaemic stroke.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (last searched November 2013), MEDLINE (1966 to November 2013) and EMBASE (1980 to November 2013). We also handsearched conference proceedings and journals, searched reference lists and contacted pharmaceutical companies and trialists.

SELECTION CRITERIA

Randomised trials of any thrombolytic agent compared with control in people with definite ischaemic stroke.

DATA COLLECTION AND ANALYSIS

Two review authors applied the inclusion criteria, extracted data and assessed trial quality. We verified the extracted data with investigators of all major trials, obtaining additional unpublished data if available.

MAIN RESULTS

We included 27 trials, involving 10,187 participants, testing urokinase, streptokinase, rt-PA, recombinant pro-urokinase or desmoteplase. Four trials used intra-arterial administration, while the rest used the intravenous route. Most data come from trials that started treatment up to six hours after stroke. About 44% of the trials (about 70% of the participants) were testing intravenous rt-PA. In earlier studies very few of the participants (0.5%) were aged over 80 years; in this update, 16% of participants are over 80 years of age due to the inclusion of IST-3 (53% of participants in this trial were aged over 80 years). Trials published more recently utilised computerised randomisation, so there are less likely to be baseline imbalances than in previous versions of the review. More than 50% of trials fulfilled criteria for high-grade concealment; there were few losses to follow-up for the main outcomes.Thrombolytic therapy, mostly administered up to six hours after ischaemic stroke, significantly reduced the proportion of participants who were dead or dependent (modified Rankin 3 to 6) at three to six months after stroke (odds ratio (OR) 0.85, 95% confidence interval (CI) 0.78 to 0.93). Thrombolytic therapy increased the risk of symptomatic intracranial haemorrhage (OR 3.75, 95% CI 3.11 to 4.51), early death (OR 1.69, 95% CI 1.44 to 1.98; 13 trials, 7458 participants) and death by three to six months after stroke (OR 1.18, 95% CI 1.06 to 1.30). Early death after thrombolysis was mostly attributable to intracranial haemorrhage. Treatment within three hours of stroke was more effective in reducing death or dependency (OR 0.66, 95% CI 0.56 to 0.79) without any increase in death (OR 0.99, 95% CI 0.82 to 1.21; 11 trials, 2187 participants). There was heterogeneity between the trials. Contemporaneous antithrombotic drugs increased the risk of death. Trials testing rt-PA showed a significant reduction in death or dependency with treatment up to six hours (OR 0.84, 95% CI 0.77 to 0.93, P = 0.0006; 8 trials, 6729 participants) with significant heterogeneity; treatment within three hours was more beneficial (OR 0.65, 95% CI 0.54 to 0.80, P < 0.0001; 6 trials, 1779 participants) without heterogeneity. Participants aged over 80 years benefited equally to those aged under 80 years, particularly if treated within three hours of stroke.

AUTHORS' CONCLUSIONS

Thrombolytic therapy given up to six hours after stroke reduces the proportion of dead or dependent people. Those treated within the first three hours derive substantially more benefit than with later treatment. This overall benefit was apparent despite an increase in symptomatic intracranial haemorrhage, deaths at seven to 10 days, and deaths at final follow-up (except for trials testing rt-PA, which had no effect on death at final follow-up). Further trials are needed to identify the latest time window, whether people with mild stroke benefit from thrombolysis, to find ways of reducing symptomatic intracranial haemorrhage and deaths, and to identify the environment in which thrombolysis may best be given in routine practice.

The L-arginine pathway in acute ischemic stroke and severe carotid stenosis: temporal profiles and association with biomarkers and outcome

BACKGROUND

Endothelial dysfunction is associated with increased levels of asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA) resulting in a decreased production of nitric oxide, which regulates the vascular tone.

METHODS

Patients with acute ischemic stroke (AIS, n = 55) and asymptomatic significant carotid stenosis (AsCS, n = 44) were prospectively investigated. L-arginine, ADMA, SDMA, S100 B, and high-sensitivity C-reactive protein (hsCRP) were serially measured within 6 hours after the onset of stroke, at 24 and 72 poststroke hours. All markers were compared with healthy subjects (n = 45). The severity of AIS was daily assessed by National Institute of Health Stroke Scale scoring.

RESULTS

Even within 6 hours after the onset of stroke, L-arginine, ADMA, and SDMA were significantly higher in patients with AIS compared with both AsCS and healthy subjects. S100 B reflecting infarct size, positively correlated with the level of SDMA at 72 poststroke hours; changes in concentration of S100 B positively correlated with changes in the concentration of ADMA by 72 hours. Change in concentration of both ADMA and SDMA correlated with the change in concentration of hsCRP. Concentrations of L-arginine and hsCRP at 72 poststroke hours, respectively, were independent predictors of poststroke infection. S100 B level measured within 6 hours after the onset of AIS and hsCRP at 72 poststroke hours were independent predictors of death.

CONCLUSIONS

Metabolites of the L-arginine pathway were elevated in the very acute phase of ischemic stroke indicating a more pronounced endothelial dysfunction compared with AsCS. An increased basal L-arginine level in patients with AIS might be an adaptive mechanism; such transient elevation of the L-arginine/ADMA ratio at 24 poststroke hours may suggest that a temporary increase of L-arginine along with decrease of ADMA might be related to the protective role of L-arginine. Changes in the L-arginine pathway are predictive of poststroke infections.

Biomarkers and acute brain injuries: interest and limits

For patients presenting with acute brain injury (such as traumatic brain injury, subarachnoid haemorrhage and stroke), the diagnosis and identification of intracerebral lesions and evaluation of the severity, prognosis and treatment efficacy can be challenging. The complexity and heterogeneity of lesions after brain injury are most probably responsible for this difficulty. Patients with apparently comparable brain lesions on imaging may have different neurological outcomes or responses to therapy. In recent years, plasmatic and cerebrospinal fluid biomarkers have emerged as possible tools to distinguish between the different pathophysiological processes. This review aims to summarise the plasmatic and cerebrospinal fluid biomarkers evaluated in subarachnoid haemorrhage, traumatic brain injury and stroke, and to clarify their related interests and limits for diagnosis and prognosis. For subarachnoid haemorrhage, particular interest has been focused on the biomarkers used to predict vasospasm and cerebral ischaemia. The efficacy of biomarkers in predicting the severity and outcome of traumatic brain injury has been stressed. The very early diagnostic performance of biomarkers and their ability to discriminate ischaemic from haemorrhagic stroke were studied.

Discovery of prognostic biomarker candidates of lacunar infarction by quantitative proteomics of microvesicles enriched plasma

Background

Lacunar infarction (LACI) is a subtype of acute ischemic stroke affecting around 25% of all ischemic stroke cases. Despite having an excellent recovery during acute phase, certain LACI patients have poor mid- to long-term prognosis due to the recurrence of vascular events or a decline in cognitive functions. Hence, blood-based biomarkers could be complementary prognostic and research tools.

Methods and Finding

Plasma was collected from forty five patients following a non-disabling LACI along with seventeen matched control subjects. The LACI patients were monitored prospectively for up to five years for the occurrence of adverse outcomes and grouped accordingly (i.e., LACI-no adverse outcome, LACI-recurrent vascular event, and LACI-cognitive decline without any recurrence of vascular events). Microvesicles-enriched fractions isolated from the pooled plasma of four groups were profiled by an iTRAQ-guided discovery approach to quantify the differential proteome. The data have been deposited to the ProteomeXchange with identifier PXD000748. Bioinformatics analysis and data mining revealed up-regulation of brain-specific proteins including myelin basic protein, proteins of coagulation cascade (e.g., fibrinogen alpha chain, fibrinogen beta chain) and focal adhesion (e.g., integrin alpha-IIb, talin-1, and filamin-A) while albumin was down-regulated in both groups of patients with adverse outcome.

Conclusion

This data set may offer important insight into the mechanisms of poor prognosis and provide candidate prognostic biomarkers for validation on larger cohort of individual LACI patients.

Serum biomarkers of brain injury to classify outcome after pediatric cardiac arrest*

OBJECTIVES

Morbidity and mortality in children with cardiac arrest largely result from neurologic injury. Serum biomarkers of brain injury can potentially measure injury to neurons (neuron-specific enolase), astrocytes (S100b), and axons (myelin basic protein). We hypothesized that serum biomarkers can be used to classify outcome from pediatric cardiac arrest.

DESIGN

Prospective observational study.

SETTING

Single tertiary pediatric hospital.

PATIENTS

Forty-three children with cardiac arrest.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We measured serum neuron-specific enolase, S100b, and myelin basic protein on days 1-4 and 7 after cardiac arrest. We recorded demographics, details of the cardiac arrest and resuscitation, and Pediatric Cerebral Performance Category at hospital discharge and 6 months. We analyzed the association of biomarker levels at 24, 48, and 72 hours with favorable (Pediatric Cerebral Performance Category 1-3) or unfavorable (Pediatric Cerebral Performance Category 4-6) outcome and mortality. Forty-three children (49% female; mean age of 5.9 ± 6.3) were enrolled and 17 (40%) died. Serum S100b concentrations peaked earliest, followed by neuron-specific enolase and finally myelin basic protein. Serum neuron-specific enolase and S100b concentrations were increased in the unfavorable versus favorable outcome group and in subjects who died at all time points (all p < 0.05). Serum myelin basic protein at 24 and 72 hours correctly classified survival but not good versus poor outcome. Using best specificity, serum S100b and neuron-specific enolase had optimal positive and negative predictive values at 24 hours to classify both favorable versus unfavorable outcome and survival, whereas serum myelin basic protein's best accuracy occurred at 48 hours. Receiver operator curves for serum S100b and neuron-specific enolase to classify favorable versus unfavorable outcome at 6 months were superior to clinical variables.

CONCLUSIONS

Preliminary data show that serum S100b, neuron-specific enolase, and myelin basic protein may aid in outcome classification of children surviving cardiac arrest.

Immunological consequences of ischemic stroke

The treatment of ischemic stroke is one of the great challenges in modern neurology. The localization and the size of the infarct determine the long-term disability of stroke survivors. Recent observations have revealed that stroke also alters the function of the immune system and vice versa: At the site of the infarct, a local inflammatory response develops that enhances brain lesion development. In experimental stroke, proof-of-concept studies confirm that inhibition of this immune response reduces lesion volume and improves outcome. In the peripheral blood of stroke patients, though, lymphocytopenia and monocyte dysfunction develop. These changes reflect a clinically relevant impairment of bacterial defense mechanisms because they are associated with an enhanced risk to acquire post-stroke infections. Stress hormones have been identified as important mediators of stroke-induced immune suppression. The pharmacological inhibition of beta adrenergic receptors, but not the inhibition of steroids, is effective in reducing infection and improving clinical outcome in experimental stroke; catecholamine release therefore appears causally related to stroke-induced immune suppression. Strong evidence supports the hypothesis that these immune alterations impact the clinical course of stroke patients. Thus, the development of new therapeutic strategies targeted to alter the immunological consequences of stroke appears promising. However, to date, the beneficial effects seen in experimental stroke have not been successfully translated into a clinical trial. This brief review summarizes the current understanding of the immunological consequences of ischemic stroke. Finally, we propose a concept that links the peripheral immune suppression with the development of local inflammation.

Molecular dialogs between the ischemic brain and the peripheral immune system: dualistic roles in injury and repair

Immune and inflammatory responses actively modulate the pathophysiological processes of acute brain injuries such as stroke. Soon after the onset of stroke, signals such as brain-derived antigens, danger-associated molecular patterns (DAMPs), cytokines, and chemokines are released from the injured brain into the systemic circulation. The injured brain also communicates with peripheral organs through the parasympathetic and sympathetic branches of the autonomic nervous system. Many of these diverse signals not only activate resident immune cells in the brain, but also trigger robust immune responses in the periphery. Peripheral immune cells then migrate toward the site of injury and release additional cytokines, chemokines, and other molecules, causing further disruptive or protective effects in the ischemic brain. Bidirectional communication between the injured brain and the peripheral immune system is now known to regulate the progression of stroke pathology as well as tissue repair. In the end, this exquisitely coordinated crosstalk helps determine the fate of animals after stroke. This article reviews the literature on ischemic brain-derived signals through which peripheral immune responses are triggered, and the potential impact of these peripheral responses on brain injury and repair. Pharmacological strategies and cell-based therapies that target the dialog between the brain and peripheral immune system show promise as potential novel treatments for 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.