CHANGE IN PLASMA S100B LEVEL AFTER ACUTE SPONTANEOUS BASAL GANGLIA HEMORRHAGE

A Prospective Cohort Study of Elevated Serum NLRP1 Levels to Prognosticate Neurological Outcome After Acute Intracerebral Hemorrhage at a Single Academic Institution

Background

Nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 1 (NLRP1) participates in neuroinflammation. This study aimed to identify serum NLRP as a potential prognostic biomarker of acute intracerebral hemorrhage (ICH).

Methods

This prospective cohort study enrolled 145 patients with supratentorial ICH and 51 healthy controls. Serum NLRP1 levels were quantified on admission of all 145 patients, on days 1, 3, 5, 7, and 10 after stroke in 51 of 145 patients and at entry into the study of controls. Poststroke 6-month modified Rankin Scale (mRS) scores of 3-6 signified a poor prognosis.

Results

Compared to controls, patients had prominently increased serum NLRP1 levels until day 10 after ICH, with the highest levels at days 1 and 3. Serum NLRP1 levels were independently correlated with National Institutes of Health Stroke Scale (NIHSS) scores, hematoma volume and six-month mRS scores, and independently predicted six-month bad prognosis. A linear relationship was observed between serum NLRP1 levels and the risk of poor prognosis in a restricted cubic spline. Under the receiver operating characteristic (ROC) curve, serum NLRP levels efficiently discriminated poor prognosis. Serum NLRP1, NIHSS, and hematoma volume were merged into a prognosis prediction model, which was portrayed using a nomogram. Good performance of the model was verified using calibration curve, decision curve, and ROC curve.

Conclusion

Serum NLRP1 levels are elevated during the early period following ICH and are independently related to hemorrhagic severity and poor prognosis, suggesting that serum NLRP1 may represent a promising prognostic biomarker of ICH.

Blood-Based Biomarkers in Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) is one of the most lethal subtypes of stroke, associated with high morbidity and mortality. Prevention of hematoma growth and perihematomal edema expansion are promising therapeutic targets currently under investigation. Despite recent improvements in the management of ICH, the ideal treatments are still to be determined. Early stratification and triage of ICH patients enable the adjustment of the standard of care in keeping with the personalized medicine principles. In recent years, research efforts have been concentrated on the development and validation of blood-based biomarkers. The benefit of looking for blood candidate markers is obvious because of their acceptance in terms of sample collection by the general population compared to any other body fluid. Given their ease of accessibility in clinical practice, blood-based biomarkers have been widely used as potential diagnostic, predictive, and prognostic markers. This review identifies some relevant and potentially promising blood biomarkers for ICH. These blood-based markers are summarized by their roles in clinical practice. Well-designed and large-scale studies are required to validate the use of all these biomarkers in the future.

Cleavage of semaphorin 4 C interferes with the neuroprotective effect of the semaphorin 4 C/Plexin B2 pathway on experimental intracerebral hemorrhage in rats

Semaphorin 4 C (SEMA4C) and its cognate receptor Plexin B2 are important regulators of axon guidance and are involved in many neurological diseases, in which SEMA4C acts not only as a ligand ("forward" mode) but also as a signaling receptor ("reverse" mode). However, the role of SEMA4C/Plexin B2 in intracerebral hemorrhage (ICH) remains unclear. In this study, ICH in adult male Sprague-Dawley rats was induced by autologous blood injection in the right basal ganglia. In vitro, cultured primary neurons were subjected to OxyHb to imitate ICH injury. Recombinant SEMA4C (rSEMA4C) and overexpressing lentiviruses encoding full-length SEMA4C or secretory SEMA4C (sSEMA4C) were administered to rats by intraventricular injection. First, we found that elevated levels of sSEMA4C in the cerebrospinal fluid (CSF) of clinical patients were associated with poor prognosis. Both SEMA4C and sSEMA4C were increased in brain tissue around the hematoma after ICH in rats. Overexpression of SEMA4C attenuated neuronal apoptosis, neurosis, and neurologic impairment after ICH. However, treatment with rSEMA4C or sSEMA4C overexpression exacerbated neuronal injury. In addition, when treated with SEMA4C overexpression, the forward mode downstream protein RhoA and the reverse mode downstream ID1/3 transcriptional factors of SEMA4C/Plexin B2 signaling were all activated. Nevertheless, when exposed to rSEMA4C or sSEMA4C overexpression, only the forward mode was activated. Thus, sSEMA4C may be a novel molecular biomarker to predict the prognosis of patients with ICH, and the prevention of SEMA4C cleavage is expected to be a promising therapeutic target.

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.

Association of Changed Serum Brain Biomarkers With Perihematomal Edema and Early Clinical Outcome in Primary ICH Patients

BACKGROUND

Perihematomal edema (PHE) following primary intracranial hemorrhages (ICHs) affects the patient outcome. Also, serum biomarkers such as S100 calcium-binding protein B (S100B) and glial fibrillary acidic protein (GFAP) have been associated with ICHs outcome. We aimed to investigate the association between these biomarkers and PHE in ICH patients.

METHODS

In this cross-sectional study, patients with primary ICH between January 2020 and August 2020 were evaluated. All participants underwent spiral brain computed tomography scans upon admission, and 48 to 72 hours later and quantification of initial hematoma volume was performed. Serum level of matrix metalloproteinase-9 (MMP-9), vascular endothelial growth factor (VEGF), GFAP, and S100B on admission were measured by enzyme-linked immunosorbent assays. Acute clinical outcome was assessed by the modified-Rankin scale, National Institute of Health Stroke Scale (NIHSS), and ICH score.

RESULTS

Thirty-seven ICH patients (21 patients with a favorable outcome and 16 unfavorable) were studied. Compared with survival patients, nonsurvivor patients showed a higher serum level of MMP-9, VEGF, GFAP, and S100B ( P <0.05). Scores of absolute PHE, edema expansion distance, and PHE growth rate in the nonsurvivor group were higher than the survivors ( P <0.001). The regression model revealed that MMP-9, VEGF, ICH score, and hematoma volume were associated with the PHE growth rate. S100B and ICH score were associated with edema expansion distance.

CONCLUSIONS

Our data showed that the serum level of molecular biomarkers was associated with higher PHE volume and PHE scores were higher in nonsurvival patients, suggesting it may have a pathogenic role in developing PHE after ICH.

Evaluating the Neuroprotective Effect of Melatonin on Patients with Hemorrhagic Stroke Using Serum S100B Protein as a Prognostic Marker

Background: Intracerebral hemorrhage (ICH) is one of the most debilitating kinds of stroke. Recent evidence shows that the proper initiation of neuroprotective agents might save at risk neurons and improve the outcome. Objectives: The focus of this study is to evaluate the neuroprotective effect of melatonin on patients with hemorrhagic stroke. Methods: Forty adult patients with confirmed nontraumatic ICH, who were admitted to the ICU within 24 hours of the stroke onset were enrolled in this study. Subjects in the melatonin group received 30 mg of melatonin every night for 5 consecutive nights. In order to evaluate the intensity of the neuronal injury, S100B was assessed once on day 1 and, day 5 post ICU admission. Additionally, the length of ICU stay, mortality, and the duration of mechanical ventilation were also recorded. Results: Forty patients completed the study. In both groups the plasma concentrations of S100B decreased after 5 days compared with their baseline values. However, this reduction was more significant in the melatonin compared to the control group (P-value < 0.05). The duration of mechanical ventilation and length of ICU stay was shorter in the melatonin group, and this difference was statistically significant for the length of ICU stay (P-value < 0.05), and marginally significant for the duration of mechanical ventilation (P-value = 0.065). The in-ICU mortality rate of the melatonin group was 15%, almost half of that of the control group (30%). However, this difference was not statistically significant. Conclusions: In conclusion, melatonin can be considered as a harmless and effective nueroprotective agent with some unique features which has made it an appropriate adjunctive medicine for critically ill intubated patients.

Arundic Acid (ONO-2506), an Inhibitor of S100B Protein Synthesis, Prevents Neurological Deficits and Brain Tissue Damage Following Intracerebral Hemorrhage in Male Wistar Rats

Stroke is one of the leading causes of mortality and neurological morbidity. Intracerebral hemorrhage (ICH) has the poorest prognosis among all stroke subtypes and no treatment has been effective in improving outcomes. Following ICH, the observed high levels of S100B protein have been associated with worsening of injury and neurological deficits. Arundic acid (AA) exerts neuroprotective effects through inhibition of astrocytic synthesis of S100B in some models of experimental brain injury; however, it has not been studied in ICH. The aim of this study was to evaluate the effects of intracerebroventricular (ICV) administration of AA in male Wistar rats submitted to ICH model assessing the following variables: reactive astrogliosis, S100B levels, antioxidant defenses, cell death, lesion extension and neurological function. Firstly, AA was injected at different doses (0.02, 0.2, 2 and 20 μg/μl) in the left lateral ventricle in order to observe which dose would decrease GFAP and S100B striatal levels in non-injured rats. Following determination of the effective dose, ICH damage was induced by IV-S collagenase intrastrial injection and 2 μg/μl AA was injected through ICV route immediately before injury. AA treatment prevented ICH-induced neurological deficits and tissue damage, inhibited excessive astrocytic activation and cellular apoptosis, reduced peripheral and central S100B levels (in striatum, serum and cerebrospinal fluid), improved neuronal survival and enhanced the antioxidant defences after injury. Altogether, these results suggest that S100B is a viable target for treating ICH and highlight AA as an interesting strategy for improving neurological outcome after experimental brain hemorrhage.

Chitinase-3-Like Protein 1, Serum Amyloid A1, C-Reactive Protein, and Procalcitonin Are Promising Biomarkers for Intracranial Severity Assessment of Traumatic Brain Injury: Relationship with Glasgow Coma Scale and Computed Tomography Volumetry

OBJECTIVE

The volume and location of intracranial hematomas are well-known prognostic factors for traumatic brain injury. The aim of this study was to determine the relationship of serum biomarkers S100β, glial fibrillary acidic protein, neuron-specific enolase, total tau, phosphorylated neurofilament heavy chain, serum amyloid A1 (SAA1), C-reactive protein, procalcitonin (PCT), and chitinase-3-like protein 1 (YKL-40) with traumatic brain injury severity and the amount and location of hemorrhagic traumatic lesions.

METHODS

A prospective observational cohort of 115 patients with a Glasgow Coma Scale (GCS) score of 3-15 were evaluated. Intracranial lesion volume was measured from the semiautomatic segmentation of hematoma on computed tomography using Analyze software. The establishment of possible biomarker cutoff points for intracranial lesion detection was estimated using the Youden Index (J) obtained from the area under the receiver operating characteristic curve.

RESULTS

SAA1, YKL-40, PCT, and S100β showed the most robust association with level of consciousness, both with total GCS and motor score. Biomarkers significantly correlated with volumetric measurements of subdural hematoma, traumatic subarachnoid hemorrhage, intraparenchymal hemorrhage, intraventricular hemorrhage, and total amount of bleeding. The type of intracranial hemorrhage was associated with various release patterns of neurobiochemical markers.

CONCLUSIONS

YKL-40, SAA1, C-reactive protein, and PCT combined with S100β were the most promising biomarkers to determine the presence, location, and extent of traumatic intracranial lesions. Combination of biomarkers further increased the discriminatory capacity for the detection of intracranial bleeding.

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.

Determination of serum neutrophil gelatinase-associated lipocalin as a prognostic biomarker of acute spontaneous intracerebral hemorrhage

BACKGROUND

Neutrophil gelatinase-associated lipocalin (NGAL) is currently known as an acute phase protein and implicated in acute brain injury. Herein, we sought to gauge serum NGAL level in patients after acute (<24 h) spontaneous intracerebral hemorrhage (ICH) and to investigate its relation to neurological outcome.

METHODS

Serum NGAL levels were measured in 106 patients and 106 controls. National Institutes of Health Stroke Scale (NIHSS) score, Glasgow coma scale (GCS) score, ICH score and hematoma volume were recorded for assessing hemorrhagic severity. An unfavorable outcome was defined as modified Rankin Scale >2 at 90 days.

RESULTS

As opposed to the controls, the patients had significantly raised serum NGAL levels. Correlations were observed between NGAL levels and serum C-reactive protein levels, blood glucose levels, GCS score, NIHSS score, ICH score and ICH volume. Multivariate analysis identified serum NGAL as a predictor for unfavorable outcome at 90 days. It also showed high prognostic ability under receiver operating characteristic curve.

CONCLUSIONS

Enhanced NGAL level is revealed after acute spontaneous ICH, in association with inflammatory degree and hemorrhagic severity, and intimately correlated with a worse prognosis.

Effects of Kudiezi Injection on Serum Inflammatory Biomarkers in Patients with Acute Cerebral Infarction

BACKGROUND

Kudiezi injection is a traditional Chinese medicine for acute cerebral infarction, but the exact mechanisms are poorly understood.

OBJECTIVE

To investigate the mechanisms of Kudiezi injection on the inflammatory response in the treatment of acute cerebral infarction.

METHODS

This was a prospective study of patients with acute cerebral infarction within 48 h of onset and treated between July 2012 and July 2016 at three hospitals in China. The patients were randomized to routine treatments (control group) versus routine treatments and Kudiezi injection (Kudiezi group). The National Institutes of Health Stroke Score was assessed on days 1, 3, 5, 7, and 14. The patients were tested for serum levels of pro- and anti-inflammatory cytokines (S100 calcium-binding protein B, neuron-specific enolase, interleukin-6, interleukin-10, interleukin-18, and matrix metaloproteinase-9; by enzyme-linked immunosorbent assay) immediately after admission and on days 3, 5, and 14.

RESULTS

Stroke scores were improved in both groups from days 1 to 14. On days 5 and 7, stroke scores in the Kudiezi group were lower than in the control group (P < 0.05). Compared with controls, the Kudiezi group had lower serum S100 calcium-binding protein B on day 14; higher interleukin-6 and interleukin-10 on day 3; lower interleukin-6 and interleukin-18 on day 5; and lower interleukin-18 and matrix metaloproteinase-9 on day 14.

CONCLUSION

Kudiezi injection could lead to early reduction of interleukin-6, interleukin-18, matrix metaloproteinase-9, neuron-specific enolase, and S100 calcium-binding protein B levels and increases of interleukin-10 levels in patients with acute ischemic stroke. This trial is registered with ClinicalTrials.gov NCT01636154.

Development and validation of the hypertensive intracerebral hemorrhage prognosis models

To develop and validate the prognosis model of hypertensive intracerebral hemorrhage based on admission characteristics, which would be applied to predict the 3-month outcome.For developing the prognosis models, we studied data from 325 patients with retrospectively consecutive hypertensive intracerebral hemorrhage admitted between 2012 and 2016. The predictive value of admission characteristics was tested in logistic regression models, presenting 3-month outcome as the primary outcome. The performance of the models was tested by discrimination and calibration. After development, internal and external validations were used to test the function.The multivariate analysis of logistic regression indicated that age, Glasgow coma scale score, pupillary light reflex, hypoxemia, intracerebral hemorrhage volume, blood glucose, and D-dimer level were independent factors of the hypertensive intracerebral hemorrhage prognosis model. The prognosis model based on those admission risk factors worked well. The receiver operating characteristic curve was used to analyze the discriminant ability of model A, model A + B, and model A + B + C. Specifically, the area under the receiver operating characteristic curve increased from 0.816 (model A; 95% CI, 0.760-0.872) to 0.913 (model A + B + C; 95% CI, 0.881-0.946), and the models were not overoptimistic and were applicably confirmed by internal and external validations respectively.This prognosis model could be used to predict the prognosis of patients with hypertensive intracerebral hemorrhage early, simply and accurately, contributing to the clinical treatment eventually.

Clinical relevance of cleaved RAGE plasma levels as a biomarker of disease severity and functional outcome in aneurysmal subarachnoid hemorrhage

BACKGROUND

Cleaved receptor for advanced glycation end-products (cRAGE) has been introduced as a new inflammatory marker. We clarified the associations between cRAGE levels, disease severity and functional outcome in aneurysmal subarachnoid hemorrhage (aSAH).

METHODS

In this prospective, observational study, plasma levels of total soluble RAGE (sRAGE) and endogenous secretory RAGE (esRAGE) were quantified in 108 aSAH patients and 108 controls. The level of cRAGE was calculated by subtracting the level of esRAGE from that of sRAGE. World Federation of Neurological Surgeons (WFNS) score, modified Fisher score, and Hunt Hess (HH) score were recorded to assess aSAH severity. Relationship between plasma cRAGE levels and 6-month poor outcome (Glasgow Outcome Scale score of 1-3) was assess using multivariate analysis.

RESULTS

Plasma cRAGE levels were significantly higher in patients than in controls. Its levels were significantly correlated with WNFS score, modified Fisher score and HH score of patients. Plasma cRAGE emerged as an independent predictor for 6-month poor outcome. Area under receiver operating characteristic curve (AUC) of this biomarker was similar to those of WNFS score, modified Fisher score and HH score. Moreover, it significantly improved AUCs of WNFS score, modified Fisher score and HH score.

CONCLUSIONS

Plasma cRAGE levels are highly associated with the severity and poor prognosis in aSAH.

Correlating S100B with disease course in a case of new onset, acquired thrombotic thrombocytopenic purpura (TTP): Could this be a new predictive biomarker in TTP?

Acute thrombotic thrombocytopenic purpura (TTP) is an aggressive thrombotic microangiopathy that if not treated, can have a 90% mortality rate. Clinical manifestations of this disease include profound thrombocytopenia, hemolytic anemia, and end-organ dysfunction. Neurologic symptoms can occur in 80% of patients and range from mild confusion to coma (Scully et al., Br J Haematol 142:819-826). Here, we present the clinical course of a patient diagnosed with new onset acquired TTP who presented with neurologic changes that waxed and waned during her disease course. In addition to usual clinical and laboratory markers for TTP severity and activity, we also collected and analyzed the protein S100B, an astroglial protein studied as a marker for central nervous system injury and impairment of the blood-brain barrier. Our hypothesis here is that because TTP involves endovascular damage, S100B could function as a biomarker for neurologic dysfunction and ultimately, predict disease activity. As illustrated in this case, our patient's S100B levels did appear to correlate with TTP disease activity and the trajectory of this protein seemed a better predictor of cognitive function. Furthermore, increased S100B velocity seemed to be the earliest indicator of a refractory TTP disease process requiring more intensive plasma exchange (TPE) therapy regimen. Therefore, we would suggest that S100B is a promising predictive biomarker of disease activity in guiding the intensity of TPE therapy for TTP as well as cognitive function.

Sinomenine enhances microglia M2 polarization and attenuates inflammatory injury in intracerebral hemorrhage

Microglia polarization plays a vital role in brain inflammatory injury following intracerebral hemorrhage (ICH). Previous studies have shown that sinomenine possesses potential immunoregulatory capabilities. However, microglia polarization's exact mechanisms in ICH remain uncertain. Therefore, we examined the role of sinomenine on microglia polarization and brain inflammation following ICH. For the experiment, autologous blood models were constructed in C57/BL6 mice. Markers of classically activated (M1) and alternatively activated (M2) microglia were detected by real-time polymerase chain reaction, immunofluorescence, and flow cytometry. Microglial toxicity was assessed using MTT and FACS assays. In addition, the neurological deficit and cerebral water content of ICH mice were also observed. Sinomenine attenuated M1 markers while promoting M2 markers of microglia. Sinomenine also protected hippocampal neurons from indirect toxicity mediated by ICH-treated microglia. Additionally, administration of sinomenine inhibited matrix metalloproteinase (MMP) 3/9 expression, cerebral water content, and neurological deficit. Therefore, sinomenine protected brain function following ICH, perhaps via M2 microglia phenotype induction and MMP 3/9 inhibition. This result suggests that sinomenine is a promising therapeutical strategy in ICH.

S100β as a biomarker for differential diagnosis of intracerebral hemorrhage and ischemic stroke

OBJECTIVE

To explore the efficacy of S100 calcium-binding protein B (S100β) in differentiating between intracerebral hemorrhage (ICH) and ischemic stroke (IS).

METHODS

From June 2014 to July 2015, 46 ICH and 71 IS patients who had undergone computed tomography (CT) scans were enrolled. Patients' neurological deficits were evaluated by the National Institutes of Health stroke scale (NIHSS), and the modified Rankin scale (mRS) was used to assess functional disability 90 days after discharge. Plasma S100β was measured from a blood sample drawn upon arrival at the emergency department.

RESULTS

The plasma S100β concentration in the ICH group was significantly higher than in the IS group (p < 0.001). There were only significant correlations between S100β and hemorrhage volume (r = 0.820, p < 0.001), NIHSS score (r = 0.389, p = 0.008), and mRS (r = 0.732, p < 0.001) in the ICH group. Furthermore, receiver-operating characteristic (ROC) curve analysis revealed that an S100β concentration of 67 pg/ml yielded an area under the curve (AUC) of 0.903 with 95.7% sensitivity and 70.4% specificity in differentiating between ICH and IS. In the ICH group, the plasma S100β concentration was significantly elevated in patients with poor functional outcome vs. those with favorable functional outcome (p < 0.001). ROC curve analysis showed that an S100β concentration of 133 pg/ml yielded an AUC of 0.924 with 100% sensitivity and 76.2% specificity in identifying ICH patients with poor functional outcome.

CONCLUSION

S100β could serve as a potential biomarker for differentiating between ICH and IS and predicting short-term functional outcome after ICH.

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.

Potential role of blood biomarkers in the management of nontraumatic intracerebral hemorrhage

BACKGROUND

Intracerebral hemorrhage (ICH), a subtype of stroke associated with high mortality and disability, accounts for 13% of all strokes. Basic and clinical research has contributed to our understanding of the complex pathophysiology of neuronal injury in ICH. Outcome rates, however, remain stable, and questions regarding acute management of ICH remain unanswered. Newer research is aiming at matching measured levels of serum proteins, enzymes, or cells to different stages of brain damage, suggesting that blood biomarkers may assist in acute diagnosis, therapeutic decisions, and prognostication. This paper provides an overview on the most promising blood biomarkers and their potential role in the diagnosis and management of spontaneous ICH.

SUMMARY

Information was collected from studies, reviews, and guidelines listed in PubMed up to November 2013 on blood biomarkers of nontraumatic ICH in humans. We describe the potential role and limitations of GFAP, S100B/RAGE, and ApoC-III as diagnostic biomarkers, β-​Amyloid as a biomarker for etiological classification, and 27 biomarkers for prognosis of mortality and functional outcome. Within the group of prognostic markers we discuss markers involved in coagulation processes (e.g., D-Dimers), neuroendocrine markers (e.g., copeptin), systemic metabolic markers (e.g., blood glucose levels), markers of inflammation (e.g., IL-6), as well as growth factors (e.g., VEGF), and others (e.g., glutamate). Some of those blood biomarkers are agents of pathologic processes associated with hemorrhagic stroke but also other diseases, whereas others play more distinct pathophysiological roles and help in understanding the basic mechanisms of brain damage and/or recovery in ICH.

KEY MESSAGES

Numerous blood biomarkers are associated with different pathophysiological pathways in ICH, and some of them promise to be useful in the management of ICH, eventually contributing additional information to current tools for diagnosis, therapy monitoring, risk stratification, or intervention. Up to date, however, no blood biomarker of ICH has been studied sufficiently to find its way into clinical routine yet; well-designed, large-scale, clinical studies addressing relevant clinical questions are needed. We suggest that the effectiveness of biomarker research in ICH might be improved by international cooperation and shared resources for large validation studies, such as provided by the consortium on stroke biomarker research (http://stroke-biomarkers.​com/page.php?title=Resources).

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.

Serum S100B protein is increased and correlates with interleukin 6, hypoperfusion indices, and outcome in patients admitted for surgical control of hemorrhage

S100B protein, an acknowledged biomarker of brain injury, has been reported to be increased in hemorrhagic shock. Also, acute hemorrhage is associated with inflammatory response. The aim of this study was to investigate the concentrations of serum S100B and the potential relationships with interleukin 6 (IL-6), severity of tissue hypoperfusion, and prognosis in patients admitted for surgical control of severe hemorrhage. Patients undergoing elective abdominal aortic aneurysm surgery participated as control subjects. Serum samples were drawn before, at the end of surgery, and after 6 and 24 h. Sixty-four patients with severe hemorrhage (23 trauma and 41 nontrauma) and 17 control subjects were included. Increased preoperative concentrations of S100B protein (1.70 ± 2.13 and 0.81 ± 1.23 μg/L) and IL-6 (241 ± 291 and 226 ± 238 pg/mL) were found in patients with traumatic and nontraumatic reason, respectively, and remained elevated throughout 24 h. Compared with nontrauma, trauma patients exhibited higher preoperative S100B levels (P < 0.05). Overall mortality was 47%. In control subjects, preoperative S100B and IL-6 levels were within normal limits and increased at the end of surgery (P < 0.001 and P < 0.01, respectively). Preoperative S100B correlated with IL-6 (r = 0.78, P < 0.01), arterial lactate (r = 0.50, P < 0.01), pH (r = -0.45, P < 0.01), and bicarbonate (r = -0.40, P < 0.01). Multiple analysis revealed that preoperative S100B in trauma and lactate in nontrauma patients were independently associated with outcome. In predicting death, preoperative S100B yielded receiver operator characteristics curve areas of 0.75 for all patients and 0.86 for those with trauma. These results indicate that severe hemorrhage in patients without brain injury is associated with increased serum levels of S100B, which correlates with IL-6 and tissue hypoperfusion. Moreover, the predictive ability of S100B for mortality, suggests that it could be a marker of potential clinical value in identifying, among patients with severe hemorrhage, those at greater risk for adverse outcome.

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.

The role of serum cholinesterase activity and S100B protein in the evaluation of organophosphate poisoning

The aim of this study was to investigate the role of serum cholinesterase (SChE) activity and S100B protein in the evaluation of patients with acute organophosphate (OP) poisoning. Patients with acute OP poisoning admitted to the emergency department were included in this cross-sectional study. Twenty healthy volunteers served as controls. The SChE activity and serum S100B were determined on admission. Patients were divided into two groups (low severity and high severity). Thirty-six patients diagnosed with acute OP poisoning were enrolled. Serum S100B concentrations were higher in patients than in the control group ( p < 0.05). In the high-severity group, the SChE levels were lower and the S100Bs levels were higher than in the low-severity group. The SChE level was not different between survivors and nonsurvivors. S100B levels were higher in nonsurvivors than in survivors. According to receiver–operating characteristic curve analysis, the optimal cutoff value of serum S100B level to predict mortality was 236.5 pg/mL, with 71.4% sensitivity and 89.7% specificity. Our data suggest that initial SChE level is related to the clinical severity but not with mortality. S100B may be a useful marker in the assessment of clinical severity and prediction of mortality in acute OP poisoning.

Serum biomarkers of spontaneous intracerebral hemorrhage induced secondary brain injury

Intracerebral hemorrhage (ICH) is a devastating form of stroke associated with a high rate of morbidity and mortality. It is now believed that much of this damage occurs in the subacute period following the initial insult via a cascade of complex pathophysiologic pathways that continues to be investigated. Increased levels of certain serum proteins have been identified as biomarkers that may reflect or directly participate in the inflammation, blood brain barrier disruption, endothelial dysfunction, and neuronal and glial toxicity that occur during this secondary period of cerebral injury. Some of these biomarkers have the potential to serve as therapeutic targets or surrogate endpoints for future research or clinical trials. Others may someday augment current clinical techniques in diagnosis, risk-stratification, prognostication, treatment decision and measurement of therapeutic efficacy. While much work remains to be done, biomarkers show significant potential to expand clinical options and improve clinical management, thereby reducing mortality and improving functional outcomes in ICH patients.

Diagnostic accuracy of plasma glial fibrillary acidic protein for differentiating intracerebral hemorrhage and cerebral ischemia in patients with symptoms of acute stroke

BACKGROUND

Glial fibrillary acidic protein (GFAP) is a biomarker candidate indicative of intracerebral hemorrhage (ICH) in patients with symptoms of acute stroke. GFAP is released rapidly in the presence of expanding intracerebral bleeding, whereas a more gradual release occurs in ischemic stroke. In this study the diagnostic accuracy of plasma GFAP was determined in a prospective multicenter approach.

METHODS

Within a 1-year recruitment period, patients suspected of having acute (symptom onset<4.5 h before admission) hemispheric stroke were prospectively included into the study in 14 stroke centers in Germany and Switzerland. A blood sample was collected at admission, and plasma GFAP was measured by use of an electrochemiluminometric immunoassay. The final diagnosis, established at hospital discharge, was classified as ICH, ischemic stroke, or stroke mimic.

RESULTS

The study included 205 patients (39 ICH, 163 ischemic stroke, 3 stroke mimic). GFAP concentrations were increased in patients with ICH compared with patients with ischemic stroke [median (interquartile range) 1.91 μg/L (0.41-17.66) vs 0.08 μg/L (0.02-0.14), P<0.001]. Diagnostic accuracy of GFAP for differentiating ICH from ischemic stroke and stroke mimic was high [area under the curve 0.915 (95% CI 0.847-0.982), P<0.001]. A GFAP cutoff of 0.29 μg/L provided diagnostic sensitivity of 84.2% and diagnostic specificity of 96.3% for differentiating ICH from ischemic stroke and stroke mimic.

CONCLUSIONS

Plasma GFAP analysis performed within 4.5 h of symptom onset can differentiate ICH and ischemic stroke. Studies are needed to evaluate a GFAP point-of-care system that may help optimize the prehospital triage and management of patients with symptoms of acute stroke.

Astroglial proteins as diagnostic markers of acute intracerebral hemorrhage-pathophysiological background and clinical findings

The time span from symptom onset to treatment initiation remains a critical variable determining the efficacy of thrombolysis in acute ischemic stroke. To date, performing a brain scan is indispensable prior to therapy in order to differentiate between patients with ischemic stroke and those with intracerebral hemorrhage (ICH). This causes substantial treatment delay, as thrombolysis cannot be applied prior to hospital admission at much earlier time points. Recently, brain-specific astroglial proteins (i.e., glial fibrillary acidic protein (GFAP), S100B) were identified to be released rapidly from the cytoplasm of destroyed cells in case of acute ICH. Elevated serum concentrations were found within the first 6 h after ICH onset. In contrast, in ischemic stroke, these proteins are released with delay, mirroring the more gradual occurrence of necrotic cell death and blood brain barrier disruption. S100B and GFAP may qualify as candidate serum biomarkers which are able to differentiate between ischemic stroke and ICH in the emergency phase of stroke. This minireview enlightens the pathophysiological background of this finding and provides an overview on currently available clinical data.