recent stroke biomarkers

Recent stroke biomarkersBy

Prof. Moustafa RizkProf. of Clinical Pathology

Faculty of Medicine, University of Alexandria

10/19/2017 5:22 AM 1

Stroke is defined as

A clinical syndrome consisting of :

Rapidly developing clinical signs of focal disturbance of cerebral function

Lasting more than 24 hours

Or leading to death

With no apparent cause other than that of vascular origin

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Stroke Types

80% ischemic

Thrombosis

Embolism

Hypoperfusion

20% hemorrhagic

Intracerebral

Subarachnoid

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Ischemic Strokes

• Thrombosis-most common cause

• Etiology

– Atherosclerotic disease-most common

– Vasculitis

– Dissection

– Polycythemia

– Hypercoagulable states

– Infectious Diseases-HIV, TB, syphilis

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Ischemic Strokes• 1/5th due to Embolism• Etiology–Cardiac• Valvular Vegetations• Mural thrombi- caused by

A-fib, MI, or dysrhythmias• Paradoxical emboli• Cardiac tumors-myxoma

– Fat emboli–Particulate emboli – IV drug injections– Septic Emboli

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Ischemic Strokes

• Hypoperfusion- less common mechanism

• Typically caused by cardiac failure

• More diffuse injury pattern vs. thrombosis or embolism

• Usually occur in watershed regions of brain

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Hemorrhagic Strokes Intracerebral hemorrhage (ICH)

- approx. 10% of all strokes– Risk Factors

• HTN• Increasing Age• Race: Asians and Blacks • Amyloidosis- esp. in the elderly• AVMs or tumors• Anticoagulants/Thrombolitic use• History of previous stroke• Tobacco, ETOH, and cocaine use

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Subarachnoid hemorrhage (SAH)

–Result from rupture of berry aneurysm or rupture of AVMs

Hemorrhagic Stroke

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A transient ischaemic attack (TIA)

Is defined as ‘stroke symptoms and signs that resolve within 24 hours’

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What is a biomarker?

Biomarkers are objectively-measured biological signatures of normal and pathologic processes that can serve a wide range of purposes such as risk stratification, therapeutic assessment strategies, clinical trial design and drug development.

A biomarker has good clinical acceptance if the biomarker is : AccurateAcceptable to the patient Easy to interpret by clinicians Has a high sensitivity and specificity for the outcome it is

expected Understanding of the differences in pharmacological

responses

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Types of stroke biomarkers

1- Biomarkers of oxidative damage

Ex. Oxidative stress index

F2-isoprostanes , Uric acid

2- Biomarkers of inflammation

Ex. Interleukin-6 , CRP

Toll-like receptors

3- Biomarkers of brain injury

Ex. Plasma microRNAs , S100β

Neuron-specific enolase

4- Lipids related Biomarkers

Ex. Apolipoprotein A-1

Fatty acid binding protein 410/19/2017 5:22 AM 11

5- Biomarkers of thrombus formation

Ex. D-dimers

Platelet reactivity

6- Biomarkers of cardiac function N-terminal pro-Brain Natriuretic Peptide High sensitivity troponin T

7- Biomarkers of stroke risk Lipoproteinassociated phospholipase A2 (Lp-PLA2) High levels of oxidized low-density lipoprotein (oxLDL) Peptide midregional proadrenomedullin (MR-proADM) Asymmetric dimethylarginine (ADMA)

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1-Biomarkers of oxidative damage

Oxidative stress index (OSI)

The ratio of total oxidant status (TOS ) level to total antioxidant status (TAS) level was considered as OSI.

OSI was calculated according to the following formula:

OSI = TOS (μmol H2O2 Eq/L) / TAS (μmol trolox Eq/L)

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AIH/healthy adults 9.101 ± 5.829/2.096 ± 1.130 p=< 0.001

ACI/healthy adults 8.844 ± 6.585/2.096 ± 1.130 p=< 0.001

American Journal of Emergency Medicine 34 (2016) 2379–2383

Investigation of oxidant and antioxidant levels in patients with acute stroke in the emergency service

• F2-isoprostanes (A family of prostaglandin isomers)

Rise in F2-isoprostanes occurred as early as three hours after ischemic stroke onset and remained elevated for several days.

• Uric acid (an antioxidant role of urate)

Uric acid levels were inversely associated with the extent of neurological deficits on admission and the final infarct volume on CT/MRI scans

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2- Biomarkers of inflammationInterleukin-6Released in the post-stroke setting and serves as a vital

messenger molecule between leucocytes, vascular endothelium, and parenchyma resident cells.

Blood levels of IL-6 have been repeatedly associated with poor outcome.

After stroke IL-6 concentration in blood has been correlated with baseline stroke severity, highlighting its plausible role as a biomarker of acute cerebral injury.

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Toll-like receptors

• Among members of the TLR family, TLR2, TLR4, TLR8 and TLR9 have been closely associated with stroke events.

• In separate studies, the expressions of TLR2 and TLR4 were associated with poor outcomes in ischemic stroke patients.

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A family of transmembrane pattern recognition receptors

3- Biomarkers of brain injury• Plasma microRNAs

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Differentially regulated miRNAs in ischemic stroke patients with different conditions i.e., acute ischemic stroke cases and ischemic stroke cases in different time scales.

M. Vijayan, P.H. Reddy / Biochimica et Biophysica Acta 1862 (2016) 1984–1993

Microarray analysis and selective TaqMan qPCR of miRNAs

Peripheral biomarkers of stroke: Focus on circulatory microRNAs

• Using microarray analysis , the researchers found that among the 836 miRNAs present on the array chip, 157 miRNAs were differentially regulated in the stroke subjects.

• Among those miRNAs, 138 miRNAs were highly expressed, and 19 were poorly expressed. Of the highly expressed miRNAs, 17 were upregulated and of the poorly expressed miRNAs, 8 were down regulated.

• The researchers found that analysis of miRNA profiling revealed the following key events that occur during stroke recovery: regulation of hypoxia, angiogenesis, and erythropoiesis/ hematopoiesis.

• They concluded that these miRNAs could be used to differentiate large artery, small artery, and cardio embolic strokes from each other.

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M. Vijayan, P.H. Reddy / Biochimica et Biophysica Acta 1862 (2016) 1984–1993

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Total RNA was separately extracted from MRI(-) acute stroke patients, MRI(+) acute stroke patients, and control subjects. Then, significant changes in the miRNA profiles wereanalyzed using pairwise comparisons between the groups. Only the miRNAs showing 2-fold changes or greater between all two groups were selected.

Journal of Stroke and Cerebrovascular Diseases, Vol. 23, No. 10 (November-December), 2014: pp 2607-2613

Circulating MicroRNAs as Novel Potential Biomarkers for Early Diagnosis of Acute Stroke in Humans

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Identification of miRNAs in plasma samples as potential biomarkers for the diagnosis of acute stroke. The 17 candidate miRNAs screened by miRNA microarray and qRT-PCR were separately detected by real-time RT-PCR in MRI(-) acute stroke

patients, MRI(+) acute stroke patients, and control subjects.

hsa-miR-106b-5P

hsa-miR-4306

hsa-miR-320d

hsa-miR-320e

Journal of Stroke and Cerebrovascular Diseases, Vol. 23, No. 10 (November-December), 2014: pp 2607-2613

23.90-fold

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Evaluation of plasma microRNAs hsa-miR-106b-5P for the diagnosis of acute stroke patients

A, ROC curves were drawn from the plasma microRNAs from 60 MRI(-) acute

stroke patients

B, ROC curves were drawn from the plasma microRNAs from 76 MRI(+) acute

stroke patients.

• S100β• Largely expressed by astrocytes and, to a lesser extent,

by neurons, microglia, and oligodendrocytes.

• S100β is protective and trophic at low concentrations,

but can also be toxic and pro-apoptotic at high levels.

• The glial protein S100β was increased in ischemic

stroke patients who present 1-7 days after the insult.

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Serum Protein S100β is a Diagnostic Biomarker for Distinguishing Posterior Circulation Stroke from Vertigo of Nonvascular Causes

European Neurology 72(5-6):278-284 · October 2014

• Neuron-specific enolase• Neuron-specific enolase (NSE) is a cytosolic brain enzyme

that functions as a glycolytic isoenzyme .

• NSE is confined solely in neurons under normal conditions and only a negligible amount of NSE is physiologically present in blood .

• NSE is released in the systemic circulation after ischemic stroke; therefore, an increase in NSE levels in the peripheral blood can be taken as an indicator of the integrity of the BBB and infarct volume.

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4- Lipids related Biomarkers

• Apolipoprotein A-1

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Journal of Stroke and Cerebrovascular Diseases, Vol. 25, No. 6 (June), 2016: pp 1360–1365

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Median Apo A-I levels were lower in ischemic stroke cases versus controls (140 versus 175 mg/dL, difference of 35 mg/dL, 95% CI −54 to −16) and in ischemic stroke versus ICH

cases (140 versus 180 mg/dL, difference of 40 mg/dL, 95% CI −57 to −23)


Apolipoprotein A-I and Paraoxonase-1 Are Potential Blood Biomarkers for

Ischemic Stroke Diagnosis

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Median paraoxonase-1 was lower in ischemic stroke cases than in both ICH cases and matched controls


Apolipoprotein A-I and Paraoxonase-1 Are Potential Blood Biomarkers for

Ischemic Stroke Diagnosis

Fatty acid binding protein 4 Involved in coordination of lipid transportation and

atherogenesis.

Expressed mainly at an inflammatory state in adipose tissue

A certain amounts of FABP4 are also found in macrophages, which are pathogenic constituents of atherosclerotic plaques.

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Fatty acid binding protein 4

Previous studies have suggested that FABP4 was associated with the following known cardiocerebrovascular diseases risk factors: insulin resistance and obesity, hypertension, atherosclerosis and diabetes.

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Circulating FABP4 levels are associated with stroke risk and clinical severity and may represent an important pathophysiological mediator of atherosclerosis, which

may point to a new target of treatment options.Although further studies are now needed to replicate these findings, data suggest

that FABP4 level shows potential as a novel biomarker for stroke risk and stroke severity.

Journal of Neuroimmunology 311 (2017) 29–34

Fatty acid binding protein 4

Fatty acid binding protein 4 is associated with stroke risk and severity in patients with acute ischemic stroke

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Journal of Stroke and Cerebrovascular Diseases, Vol. 23, No. 5 (May-June), 2014: pp 910-918

Do we need a panel of biomarkers ?

Characteristics of the 5-variable model predicting ischemic stroke vs.

mimic, ischemic stroke + ICH vs. mimic

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Receiver operating characterisitc curves. Discriminating capacity of 3 sets of predictors including (1) red: age, race, sex; (2) green: the 5 tested biomarkers;

and (3) black: age, race, and sex plus the 5 tested biomarkers.


Ischemic stroke vs. Mimic Ischemic stroke+ICH vs. Mimic Ischemic stroke vs. ICH

A Blood-based Biomarker Panel to Detect Acute Stroke

THANK YOU

PROF./MOUSTAFA RIZK

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recent stroke biomarkers

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