The Role of Circulating Platelets Microparticles and Platelet Parameters in Acute Ischemic Stroke Patients

Systemic-inflammatory indices and clinical outcomes in patients with anterior circulation acute ischemic stroke undergoing successful endovascular thrombectomy

Background

There is a lack of comprehensive profile assessment on complete blood count (CBC)-derived systemic-inflammatory indices, and their correlations with clinical outcome in patients with anterior circulation acute ischemic stroke (AIS) who achieved successful recanalization by endovascular thrombectomy (EVT).

Methods

Patients with anterior circulation AIS caused by large vessel occlusion (AIS-LVO) were retrospectively screened from December 2018 to December 2022. Systemic-inflammatory indices including ratios of neutrophil-to-lymphocyte (NLR), monocyte-to-lymphocyte (MLR), platelet-to-lymphocyte (PLR), and platelet-to-neutrophil (PNR), systemic immune-inflammation index (SII), systemic inflammation response index (SIRI), and aggregate inflammation systemic index (AISI) on admission and the first day post-EVT were calculated. Their correlations with symptomatic intracranial hemorrhage (sICH) and unfavorable 90-day functional outcome (modified Rankin Scale score of 3-6) were analyzed.

Results

A total of 482 patients [65 (IQR, 56-72) years; 33 % female] were enrolled, of which 231 (47.9 %) had unfavorable 90-day outcome and 50 (10.4 %) developed sICH. Day 1 neutrophil and monocyte counts, NLR, MLR, PLR, SII, SIRI, and AISI were increased, while lymphocyte and PNR were decreased compared to their admission levels. In multivariate analyses, neutrophil count, NLR, SII, and AISI on day 1 were independently associated with 90-day functional outcome. Moreover, day 1 neutrophil count, NLR, MLR, PLR, PNR, SII, and SIRI were independently linked to the occurrence of sICH. No admission variables were identified as independent risk factors for patient outcomes.

Conclusion

CBC-derived systemic-inflammatory indices measured on the first day after successful EVT are predictive of 90-day functional outcome and the sICH occurrence in patients with anterior circulation AIS-LVO.

Neutrophil extracellular traps mediated by platelet microvesicles promote thrombosis and brain injury in acute ischemic stroke

AIMS

Neutrophil extracellular traps (NETs) have been implicated in thrombotic diseases. There is no definitive explanation for how NETs form during acute ischemic strokes (AIS). The purpose of our study was to investigate the potential mechanism and role of NETs formation in the AIS process.

METHODS

As well as 45 healthy subjects, 45 patients with AIS had ELISA tests performed to detect NET markers. Expression of high-mobility group box 1 (HMGB1) on platelet microvesicles (PMVs) was analyzed by flow cytometry in healthy subjects and AIS patients' blood samples. We established middle cerebral artery occlusion (MCAO) mice model to elucidate the interaction between PMPs and NETs.

RESULTS

A significant elevation in NET markers was found in patient plasma in AIS patients, and neutrophils generated more NETs from patients' neutrophils. HMGB1 expression was upregulated on PMVs from AIS patients and induced NET formation. NETs enhanced Procoagulant activity (PCA) through tissue factor and via platelet activation. Targeting lactadherin in genetical and in pharmacology could regulate the formation of NETs in MCAO model.

CONCLUSIONS

NETs mediated by PMVs derived HMGB1 exacerbate thrombosis and brain injury in AIS. Video Abstract.

Relationship between baseline mean platelet volume (MPV) and prognosis of patients with acute mild cerebral infarction undergoing intravenous thrombolysis with Alteplase

Objective

To investigate the relationship between baseline, mean platelet volume (MPV) and prognosis of patients with acute mild cerebral infarction undergoing intravenous thrombolysis with alteplase.

Methods

A retrospective analysis was conducted of clinical imaging and laboratory data of patients with acute mild cerebral infarction who received intravenous thrombolytic therapy with alteplase in Baoding No.1 Central Hospital between March 2018 and March 2021. According to mRS scores after three months, a total of 140 patients were divided into the good prognosis group(n=115) (mRS score

Results

Logistic regression analysis showed that 24 hour NIHSS score after thrombolysis and baseline MPV were independently correlated with 3-month prognosis. The ROC curve indicated an optimal cutoff value of 9.65 fl for MPV in predicting poor prognosis. The study also found that the increase of baseline MPV had a close bearing on the risk increase of END.

Conclusion

Baseline MPV is an independent risk factor for early neurological deterioration and three months poor prognosis in patients with acute mild cerebral infarction undergoing intravenous thrombolysis.

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Key Words

• Ischemic stroke
• Mean platelet volume
• Prognosis
• Thrombolytic therapy

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Affiliation(s)

Yanhao Wang Yanhao Wang, Department of Neurology, Baoding No.1 Central Hospital, Baoding 071000, Hebei, China
Xiaoqing Wei Xiaoqing Wei, Department of Neurology, Baoding No.1 Central Hospital, Baoding 071000, Hebei, China
Wei Du Wei Du, Department of Neurology, Baoding No.1 Central Hospital, Baoding 071000, Hebei, China
Congcong Yuan Congcong Yuan, Department of Neurology, Baoding No.1 Central Hospital, Baoding 071000, Hebei, China

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Applicability of the low-grade inflammation score in predicting 90-day functional outcomes after acute ischemic stroke

BACKGROUND AND PURPOSE

The low-grade inflammation (LGI) score, a novel indicator of chronic LGI, combines C-reactive protein (CRP), leukocyte counts, the neutrophil/lymphocyte ratio (NLR), and the platelet (PLT) count to predict outcomes of patients with various conditions, such as cardiovascular diseases, cancers, and neurodegenerative diseases. However, few studies have examined the role of the LGI score in predicting functional outcomes of patients with ischemic stroke. The present study aimed to evaluate the association between the LGI score and functional outcomes of patients with ischemic stroke.

METHODS

A total of 1,215 patients were screened in the present study, and 876 patients were finally included in this retrospective observational study based on the inclusion and exclusion criteria. Blood tests were conducted within 24 h of admission. Severity of ischemic stroke was assessed using the NIHSS score with severe stroke denoted by NIHSS > 5. Early neurological deterioration (END) was defined as an increment in the total NIHSS score of ≥ 2 points within 7 days after admission. Patient outcomes were assessed on day 90 after stroke onset using the modified Rankin Scale (mRS).

RESULTS

The LGI score was positively correlated with baseline and the day 7 NIHSS scores (R2 = 0.119, p < 0.001;R2 = 0.123, p < 0.001). Multivariate regression analysis showed that the LGI score was an independent predictor of stroke severity and END. In the crude model, the LGI score in the fourth quartile was associated with a higher risk of poor outcomes on day 90 compared with the LGI score in the first quartile (OR = 5.02, 95% CI: 3.09-8.14, p for trend < 0.001). After adjusting for potential confounders, the LGI score in the fourth quartile was independently associated with poor outcomes on day 90 (OR = 2.65, 95% CI: 1.47-4.76, p for trend = 0.001). Finally, the ROC curve analysis showed an AUC of 0.682 for poor outcomes on day 90 after stroke onset.

CONCLUSION

The LGI score is strongly correlated with the severity of acute ischemic stroke and that the LGI score might be a good predictor for poor outcomes on day 90 in patients with acute ischemic stroke.

Deposition of platelet-derived microparticles in podocytes contributes to diabetic nephropathy

BACKGROUND

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease in the developed world. Podocyte injury is a critical cellular event involved in the progression of DN. Our previous studies demonstrated that platelet-derived microparticles (PMPs) mediated endothelial injury in diabetic rats. This study aimed to investigate whether PMPs are deposited in podocytes and to assess their potential effects on podocyte injury in DN.

METHODS

The deposition of PMPs in podocytes was assessed by immunofluorescent staining and electron microscopy. The changes in renal pathology and ultra-microstructure were assessed by periodic acid-Schiff staining and electron microscopy, respectively. The expression of inflammatory cytokines and extracellular matrix proteins was measured by immuno-histochemical staining and western blot.

RESULTS

PMPs were widely deposited in podocytes of glomeruli in diabetic patients and animal models and closely associated with DN progression. Interestingly, aspirin treatment significantly inhibited the accumulation of PMPs in the glomeruli of diabetic rats, alleviated mesangial matrix expansion and fusion of foot processes, and decreased the protein expression of inflammatory cytokines and extracellular matrix secretion. An in vitro study further confirmed the deposition of PMPs in podocytes. Moreover, PMP stimulation induced the phenotypic transition of podocytes through decreased podocin protein expression and increased protein expression of α-SMA and fibronectin, which was correlated with increased production of inflammatory cytokines.

CONCLUSION

Our findings demonstrated for the first time that the deposition of PMPs in podocytes contributed to the development of DN.

Plasma levels of platelet-enriched microRNAs change during antiplatelet therapy in healthy subjects

Platelets are the main effectors of primary hemostasis but also cause thrombosis in pathological conditions. Antiplatelet drugs are the cornerstone for the prevention of adverse cardiovascular events. Monitoring the extent of platelet inhibition is essential. Currently available platelet function tests come with constraints, limiting use in antiplatelet drug development as well as in clinical routine. With this study, we aim to investigate whether plasma miRNAs might be suitable biomarkers for monitoring antiplatelet treatment. Platelet-poor plasma was obtained from a trial including 87 healthy male volunteers that either received ticagrelor (n = 44) or clopidogrel (n = 43). Blood was collected before drug intake and after 2 h, 6 h, and 24 h. We measured a panel of 11 platelet-enriched miRNAs (thrombomiRs) by RT-qPCR and selected four biomarker candidates (i.e., miR-223-3p, miR-150-5p, miR-126-3p, miR-24-3p). To further characterize those miRNAs, we performed correlation analyses with the number of extracellular vesicles and clotting time dependent on procoagulant vesicles (PPL assay). We show that platelet-enriched miRNAs in the circulation are significantly reduced upon P2Y12-mediated platelet inhibition. This effect occurred fast, reaching its peak after 2 h. Additionally, we demonstrate that higher baseline levels of thrombomiRs are linked to a stronger reduction upon antiplatelet therapy. Finally, we show that miRNAs from our panel might be the cargo of platelet-derived and procoagulant vesicles. In conclusion, we provide evidence that thrombomiR levels change within 2 h after pharmacological platelet inhibition and circulate the body within platelet-derived and procoagulant extracellular vesicles, rendering them potential biomarker candidates for the assessment of in vivo platelet function.

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

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

Mechanisms and Biomarker Potential of Extracellular Vesicles in Stroke

Simple Summary

A stroke occurs when there is a lack of blood flow to the brain. Stroke injures the brain and can have devastating outcomes depending on the size and location of the brain tissue affected. Currently, there are only a limited number of treatment options for stroke. Extracellular vesicles are small vesicles secreted by cells. Importantly, extracellular vesicles have specific markers indicating the cell they were released from and can pass from the brain into the blood. For these reasons, assessing extracellular vesicles in the blood may create a window into changes occurring in the brain. Assessing changes in extracellular vesicles in the blood during stroke may produce new insight into the cellular changes in the brain causing injury during stroke. This in turn may generate potential targets for the development of future treatments. We summarize what is known about changes in brain-cell-specific extracellular vesicles during stroke and stress the importance of continuing to study these changes.

Abstract

Stoke is a prevalent and devastating neurologic condition with limited options for therapeutic management. Since brain tissue is rarely accessible clinically, peripheral biomarkers for the central nervous system’s (CNS’s) cellular response to stroke may prove critical for increasing our understanding of stroke pathology and elucidating novel therapeutic targets. Extracellular vesicles (EVs) are cell-derived, membrane-enclosed vesicles secreted by all cell types within the CNS that can freely pass the blood-brain barrier (BBB) and contain unique markers and content linked to their cell of origin. These unique qualities make brain-derived EVs novel candidates for non-invasive blood-based biomarkers of both cell specificity and cell physiological state during the progression of stroke and recovery. While studies are continuously emerging that are assessing the therapeutic potential of EVs and profiling EV cargo, a vast minority of these studies link EV content to specific cell types. A better understanding of cell-specific EV release during the acute, subacute, and chronic stages of stroke is needed to further elucidate the cellular processes responsible for stroke pathophysiology. Herein, we outline what is known about EV release from distinct cell types of the CNS during stroke and the potential of these EVs as peripheral biomarkers for cellular function in the CNS during stroke.

Circulating microparticles as indicators of cardiometabolic risk in PCOS

Polycystic ovary syndrome (PCOS), the most prevalent endocrine disturbance of the female reproductive system, is associated with several pathologic conditions, such as metabolic syndrome, obesity, diabetes, dyslipidemia, and insulin resistance, all of which are tightly connected to its progression. These factors are associated with a type of extracellular vesicle, ie, microparticles (MPs), released by shedding due to cell activation and apoptosis. Circulating MPs (cMPs) are secreted by a variety of cells, such as platelets, endothelial, leukocytes, and erythrocytes, and contain cytoplasmic substances derived from parent cells that account for their biologic activity. Current evidence has clearly shown that increased cMPs contribute to endothelial dysfunction, diabetes, hypertriglyceridemia, metabolic syndrome, cardiovascular abnormalities as well as PCOS. It has also been reported that platelet and endothelial MPs are specifically increased in PCOS thus endangering vascular health and subsequent cardiovascular disease. Given the importance of cMPs in the pathophysiology of PCOS, we review the role of cMPs in PCOS with a special focus on cardiometabolic significance.

Diagnostic Performance of Circulating miRNAs and Extracellular Vesicles in Acute Ischemic Stroke

Background: Increased inflammation activates blood coagulation system, higher platelet activation plays a key role in the pathophysiology of ischemic stroke (IS). During platelet activation and aggregation process, platelets may cause increased release of several proinflammatory, and prothrombotic mediators, including microRNAs (miRNAs) and extracellular vesicles (EVs). In the current study we aimed to assess circulating miRNAs profile related to platelet function and inflammation and circulating EVs from platelets, leukocytes, and endothelial cells to analyse their diagnostic and predictive utility in patients with acute IS. Methods: The study population consisted of 28 patients with the diagnosis of the acute IS. The control group consisted of 35 age- and gender-matched patients on acetylsalicylic acid (ASA) therapy without history of stroke and/or TIA with established stable coronary artery disease (CAD) and concomitant cardiovascular risk factors. Venous blood samples were collected from the control group and patients with IS on ASA therapy (a) 24 h after onset of acute IS, (b) 7-days following index hospitalization. Flow cytometry was used to determine the concentration of circulating EVs subtypes (from platelets, leukocytes, and endothelial cells) in platelet-depleted plasma and qRT-PCR was used to determine several circulating plasma miRNAs (miR-19a-3p, miR-186-5p and let-7f). Results: Patients with high platelet reactivity (HPR, based on arachidonic acid-induced platelet aggregometry) had significantly elevated platelet-EVs (CD62+) and leukocyte-EVs (CD45+) concentration compared to patients with normal platelet reactivity at the day of 1 acute-stroke (p = 0.012, p = 0.002, respectively). Diagnostic values of baseline miRNAs and EVs were evaluated with receiver operating characteristic (ROC) curve analysis. The area under the ROC curve for miR-19a-3p was 0.755 (95% CI, 0.63–0.88) p = 0.004, for let-7f, it was 0.874 (95% CI, 0.76–0.99) p = 0.0001; platelet-EVs was 0.776 (95% CI, 0.65–0.90) p = 0.001, whereas for leukocyte-EVs, it was 0.715 (95% CI, 0.57–0.87) p = 0.008. ROC curve showed that pooling the miR-19a-3p expressions, platelet-EVs, and leukocyte-EVs concentration yielded a higher AUC than the value of each individual biomarker as AUC was 0.893 (95% CI, 0.79–0.99). Patients with moderate stroke had significantly elevated miR-19a-3p expression levels compared to patients with minor stroke at the first day of IS. (AUC: 0.867, (95% CI, 0.74–0.10) p = 0.001). Conclusion: Combining different biomarkers of processes underlying IS pathophysiology might be beneficial for early diagnosis of ischemic events. Thus, we believe that in the future circulating biomarkers might be used in the prehospital phase of IS. In particular, circulating plasma EVs and non-coding RNAs including miRNAs are interesting candidates as bearers of circulating biomarkers due to their high stability in the blood and making them highly relevant biomarkers for IS diagnostics.

Extracellular Vesicles and Thrombogenicity in Atrial Fibrillation

Extracellular vesicles (EVs) are defined as a heterogenic group of lipid bilayer vesicular structures with a size in the range of 30–4000 nm that are released by all types of cultured cells. EVs derived from platelets, mononuclears, endothelial cells, and adipose tissue cells significantly increase in several cardiovascular diseases, including in atrial fibrillation (AF). EVs are engaged in cell-to-cell cooperation, endothelium integrity, inflammation, and immune response and are a cargo for several active molecules, such as regulatory peptides, receptors, growth factors, hormones, and lipids. Being transductors of the intercellular communication, EVs regulate angiogenesis, neovascularization, coagulation, and maintain tissue reparation. There is a large amount of evidence regarding the fact that AF is associated with elevated levels of EVs derived from platelets and mononuclears and a decreased number of EVs produced by endothelial cells. Moreover, some invasive procedures that are generally performed for the treatment of AF, i.e., pulmonary vein isolation, were found to be triggers for elevated levels of platelet and mononuclear EVs and, in turn, mediated the transient activation of the coagulation cascade. The review depicts the role of EVs in thrombogenicity in connection with a risk of thromboembolic complications, including ischemic stroke and systemic thromboembolism, in patients with various forms of AF.

Early Change in Platelet Count and MPV Levels of Patients Who Received Hemodialysis for the First Time: Mogadishu Somalia Experience

INTRODUCTION

Mean platelet volume (MPV) is a marker used to assess the platelet' size and is also an indicator of platelet reactivity and prothrombotic status.

OBJECTIVE

In this study, we aimed to determine the relationship between MPV and biochemical parameters in patients who had received hemodialysis (HD) for the first time and then in respect of those same patients after their fourth HD.

METHOD

151 HD patients were enrolled in this study. Patients were eligible for inclusion if they had received their first HD session during this study protocol. Prehemodialysis blood samples were taken. Most laboratory values, including mean platelet volume (MPV) level and platelets (PLT) count, were measured before the first HD and after the fourth HD session for each patient.

RESULTS

Among the patients in our study, the mean age profile of the male patients (n = 103; 68.2%) was found to be higher than that of the female patients (n = 48; 31.8%) (53.62 ± 18.19 vs. 46.17 ± 17.9 years) (p = 0.019).In the patients' laboratory results after the fourth HD session, MPV, MPV/Plt, and Na values had increased to those after the first HD session (p < 0.001). When age and gender status were taken into account, the level of weak positive correlation with white blood cell count (WBC), neutrophil, and red cell distribution width (RDW) was found, while the weak negative correlation with platelet to lymphocyte ratio (PLR) was found (p < 0.001).

CONCLUSIONS

In our study, we found that increase in MPV and MPV/PLT levels was significant in the fourth HD session of patients with CKD. It is also debatable that there are findings indicating an increase in platelet reactivity in the first weeks of the onset of HD. This could be an early indicator of the early prevention of cardiovascular diseases.

Influence of Thrombocytopenia on the Outcome of Mechanical Thrombectomy in Patients with Acute Ischemic Stroke

OBJECTIVES

Mechanical thrombectomy (MT) has become leading treatment option for acute ischemic stroke (AIS) due to large vessels occlusion (LVO). Platelet counts may affect outcome in patients with AIS or transient ischemic attack. The aim of our study was to determine the influence of thrombocytopenia on the safety and efficacy of MT in patients with AIS due to anterior circulation LVO.

MATERIALS AND METHODS

This study included 127 consecutive adult patients with AIS due to anterior circulation LVO who underwent MT. The patients were divided into 2 groups based on initial platelet count: with thrombocytopenia (<150 × 10⁹/L) and without thrombocytopenia (≥150 × 10⁹/L). Primary safety outcome was symptomatic intracerebral haemorrhage (SICH), while secondary safety outcome was stroke-related mortality. Efficacy outcome was functional independence, defined as modified Rankin Scale (mRS) score 0-2. Follow- up time was 90 days.

RESULTS

Initial thrombocytopenia (<150 × 10⁹/L) was detected in 19 (15%) patients. Multivariable analysis showed that initial thrombocytopenia did not increase the risk of SICH and did not affect the short-term functional outcome (p = 0.587). However, initial thrombocytopenia increased the risk for stroke-related mortality (aOR 3.639, 95% CI 1.079-12.641, p = 0.037). The main cause of mortality in the group with thrombocytopenia was malignant cerebral infarction (44.4%).

CONCLUSIONS

Thrombocytopenia does not affect the efficacy and the risk of SICH in patients with AIS caused by anterior circulation LVO treated with MT. However, the risk of mortality is higher in patients with thrombocytopenia, mainly due to malignant cerebral infarction.

The Dynamic of Extracellular Vesicles in Patients With Subacute Stroke: Results of the "Biomarkers and Perfusion-Training-Induced Changes After Stroke" (BAPTISe) Study

Objective: Extracellular vesicles (EV) are sub-1 μm bilayer lipid coated particles and have been shown play a role in long-term cardiovascular outcome after ischemic stroke. However, the dynamic change of EV after stroke and their implications for functional outcome have not yet been elucidated. Methods: Serial blood samples from 110 subacute ischemic stroke patients enrolled in the prospective BAPTISe study were analyzed. All patients participated in the PHYS-STROKE trial and received 4-week aerobic training or relaxation sessions. Levels of endothelial-derived (EnV: Annexin V+, CD45-, CD41-, CD31+/CD144+/CD146+), leukocyte-derived (LV: Annexin V+, CD45+, CD41-), monocytic-derived (MoV: Annexin V+, CD41-, CD14+), neuronal-derived (NV: Annexin V+, CD41-, CD45-, CD31-, CD144-, CD146-, CD56+/CD171+/CD271+), and platelet-derived (PV: Annexin V+, CD41+) EV were assessed via fluorescence-activated cell sorting before and after the trial intervention. The levels of EV at baseline were dichotomized at the 75th percentile, with the EV levels at baseline above the 75th percentile classified as "high" otherwise as "low." The dynamic of EV was classified based on the difference between baseline and post intervention, defining increases above the 75th percentile as "high increase" otherwise as "low increase." Associations of baseline levels and change in EV concentrations with Barthel Index (BI) and cardiovascular events in the first 6 months post-stroke were analyzed using mixed model regression analyses and cox regression. Results: Both before and after intervention PV formed the largest population of vesicles followed by NV and EnV. In mixed-model regression analyses, low NV [-8.57 (95% CI -15.53 to -1.57)] and low PV [-6.97 (95% CI -13.92 to -0.01)] at baseline were associated with lower BI in the first 6 months post-stroke. Patients with low increase in NV [8.69 (95% CI 2.08-15.34)] and LV [6.82 (95% CI 0.25-13.4)] were associated with reduced BI in the first 6 months post-stroke. Neither baseline vesicles nor their dynamic were associated with recurrent cardiovascular events. Conclusion: This is the first report analyzing the concentration and the dynamic of EV regarding associations with functional outcome in patients with subacute stroke. Lower levels of PV and NV at baseline were associated with a worse functional outcome in the first 6 months post-stroke. Furthermore, an increase in NV and LV over time was associated with worse BI in the first 6 months post-stroke. Further investigation of the relationship between EV and their dynamic with functional outcome post-stroke are warranted. Clinical Trial Registration: clinicaltrials.gov/, identifier: NCT01954797.

Prognostic role of neutrophil lymphocyte ratio and mean platelet volume in Bell's palsy: Comparison of diabetic and non-diabetic patients

OBJECTIVES

A low Neutrophil Lymphocyte Ratio (NLR) has been shown to be associated with good prognosis in Bell's Palsy (BP). However, the effect of chronic diseases that may affect the NLR, including Diabetes Mellitus (DM), has not been clarified in this context. This study aimed to evaluate the relationship between NLR and Mean Platelet Volume (MPV) in BP according to whether it is accompanied by DM, and their relationship with prognosis.

METHODS

A prospective observational study was conducted from May 2014 to May 2020 in a tertiary referral center, of all 79 consecutive participants diagnosed with BP in department of otolaryngology and 110 consecutive healthy participants admitted to the check-up unit. Patients diagnosed with BP were divided into two groups according to whether they were diagnosed with DM: diabetic BP patients (DM-BP, n = 33) and non-diabetic BP patients without any chronic disease (nonDM-BP, n = 46). Neutrophil (NEUT) and Lymphocyte (LYM) counts, and Mean Platelet Volume (MPV) were assessed from peripheral blood samples, and the NLR was calculated. Prognosis was evaluated using the House-Brackmann Score (HBS) six months after diagnosis.

RESULTS

The mean NLR was 2.85 ± 1.85 in BP patients and 1.69 ± 0.65 in the control group. The mean NLR was significantly higher in BP patients than healthy controls (p < 0.001). The mean NLR was 2.58 ± 1.83 in the nonDM-BP group, 3.23 ± 1.83 in the DM-BP group, and 1.69 ± 0.65 in the control group. The NLR was significantly higher in the nonDM-BP and DM-BP groups than in the control group (p < 0.05). The recovery was 90% according to the HBS. The optimal cut-off value was 2.41 (p = 0.5).

CONCLUSION

The NLR was increased in both diabetic and non-diabetic BP and had similar prognostic value in predicting the HBS before treatment in diabetic and non-diabetic patients with BP. MPV wasn't significantly different in diabetic and non-diabetic BP patients compared with the normal population.

Comprehensive Analysis of Potential miRNA-Target mRNA-Immunocyte Subtype Network in Cerebral Infarction

INTRODUCTION

Cerebral infarction (CI) is one of the leading causes of serious long-term disability and mortality.

OBJECTIVE

We aimed to identify potential miRNAs and target mRNAs and assess the involvement of immunocyte infiltration in the process of CI.

METHODS

First, miRNA and mRNA data were downloaded from the Gene Expression Omnibus database, followed by differential expression analysis. Second, correlation analysis between differentially expressed mRNAs and differential immunocyte subtypes was performed through the CIBERSORT algorithm. Third, the regulatory network between miRNAs and immunocyte subtype-related mRNAs was constructed followed by the functional analysis of these target mRNAs. Fourth, correlation validation between differentially expressed mRNAs and differential immunocyte subtypes was performed in the GSE37587 dataset. Finally, the diagnostic ability of immunocyte subtype-related mRNAs was tested.

RESULTS

Up to 17 differentially expressed miRNAs and 3,267 differentially expressed mRNAs were identified, among which 310 differentially expressed mRNAs were significantly associated with immunocyte subtypes. Several miRNA-target mRNA-immunocyte subtype networks including hsa-miR-671-3p-ZC3HC1-neutrophils, hsa-miR-625-CD5-monocytes, hsa-miR-122-ACOX1/DUSP1/NEDD9-neutrophils, hsa-miR-455-5p-SLC24A4-monocytes, and hsa-miR-455-5p-SORL1-neutrophils were identified. LAT, ACOX1, DUSP1, NEDD9, ZC3HC1, BIN1, AKT1, DNMT1, SLC24A4, and SORL1 had a potential diagnostic value for CI.

CONCLUSIONS

The network including miRNA, target mRNA, and immunocyte subtype may be novel regulators and diagnostic and therapeutic targets in CI.

Zebrafish as a preclinical model for Extracellular Vesicle-based therapeutic development

Extracellular Vesicles (EVs) are released during various pathophysiological processes and reflect the state of their cell of origin. Once released, they can propagate through biological fluids, target cells, deliver their content and elicit functional responses. These specific features would allow their harnessing as biomarkers, drug nano-vehicles and therapeutic intrinsic modulators. However, the further development of their potential therapeutic application is hampered by the lack of knowledge about how EVs behave in vivo. Recent advances in the field of imaging EVs in vivo now allow live-tracking of endogenous and exogenous EV in various model organisms at high spatiotemporal resolution to define their distribution, half-life and fate. This review highlights current imaging tools available to image EVs in vivo and how live imaging especially in the zebrafish embryo can bring further insights into the characterization of EVs dynamics, biodistribution and functions to potentiate their development for therapeutic applications.

Evaluation of combining Alberta Stroke Program Early CT Score (ASPECTS) with mean platelet volume, plateletcrit, and platelet count in predicting short- and long-term prognosis of patients with acute ischemic stroke

BACKGROUND

There is controversy regarding Alberta Stroke Program Early CT Score (ASPECTS) and platelet indices as predictors of outcome in patients with acute ischemic stroke (AIS). We aimed to assess the prognostic value of ASPECTS, mean platelet volume (MPV), plateletcrit (PCT), and platelet count (Plt) in 3-month and 1-year functional outcomes of AIS patients, both independently and in combination.

METHODS

This prospective study was conducted in Shams Al-shomuos and Ghaem hospitals of Mashhad, Iran from June 2019 to January 2021. Overall, 553 patients above 18 years old with first-ever anterior circulation AIS met the eligibility criteria and were included. Clinical, hematologic, radiologic, and demographic data of patients were recorded at baseline. The 3-month and 1-year functional outcome was evaluated by modified Rankin Scale (mRS). Multivariate logistic regression was used to determine the independent predictors of poor functional outcome (mRS>2) and mortality.

RESULTS

The mean age of the patients was 65.50 ± 14.41 years and 282 patients (51%) were male. ASPECTS ≤ 7 was an independent predictor of both poor function (OR=1.94, 95%CI=1.04-3.62, P = 0.04) and mortality (OR=2.02, 95%CI=1.14-3.58, P = 0.02) at 1 year. MPV was also a strong predictor of 3-month (OR=3.88, 95%CI=2.04-7.38, P = 0.02) and 1-year (OR=3.32, 95%CI=1.91-5.78, P = 0.01) mortality, as well as 3-month (OR=3.25, 95%CI=1.80-5.86, P < 0.001) and 1-year (OR=4.35, 95%CI=2.36-8.02, P < 0.001) poor function. For 1-year poor function (OR=9.33, 95%CI=2.19-39.73, P = 0.003) and mortality (OR=6.40, 95%CI=2.09-19.64, P = 0.001), ASPECTS combined with all platelet indices found to be a more robust independent predictor compared to each variable alone.

CONCLUSION

Although MPV is an independent predictor of both 3-month and 1-year poor function and mortality in AIS patients, ASPECTS ≤ 7 was found to be a risk factor for 1-year poor function and mortality. Moreover, the prognostic value of both platelet indices and ASPECTS are greater when they are combined together in AIS patients.

Inhibition of Phosphodiesterase 3A by Cilostazol Dampens Proinflammatory Platelet Functions

OBJECTIVE

platelets possess not only haemostatic but also inflammatory properties, which combined are thought to play a detrimental role in thromboinflammatory diseases such as acute coronary syndromes and stroke. Phosphodiesterase (PDE) 3 and -5 inhibitors have demonstrated efficacy in secondary prevention of arterial thrombosis, partially mediated by their antiplatelet action. Yet it is unclear whether such inhibitors also affect platelets' inflammatory functions. Here, we aimed to examine the effect of the PDE3A inhibitor cilostazol and the PDE5 inhibitor tadalafil on platelet function in various aspects of thromboinflammation. Approach and results: cilostazol, but not tadalafil, delayed ex vivo platelet-dependent fibrin formation under whole blood flow over type I collagen at 1000 s-1. Similar results were obtained with blood from Pde3a deficient mice, indicating that cilostazol effects are mediated via PDE3A. Interestingly, cilostazol specifically reduced the release of phosphatidylserine-positive extracellular vesicles (EVs) from human platelets while not affecting total EV release. Both cilostazol and tadalafil reduced the interaction of human platelets with inflamed endothelium under arterial flow and the release of the chemokines CCL5 and CXCL4 from platelets. Moreover, cilostazol, but not tadalafil, reduced monocyte recruitment and platelet-monocyte interaction in vitro.

CONCLUSIONS

this study demonstrated yet unrecognised roles for platelet PDE3A and platelet PDE5 in platelet procoagulant and proinflammatory responses.

Increased Levels of Platelets and Endothelial-Derived Microparticles in Patients With Non-Valvular Atrial Fibrillation During Rivaroxaban Therapy

It is known that atrial fibrillation (AF) is associated with the procoagulant state. Several studies have reported an increase of circulating microparticles in AF, which may be linked to a hypercoagulable state, atrial thrombosis and thromboembolism. We evaluated in our study alterations in both platelet (PMP, CD42b) and endothelial-derived (EMP, CD144) microparticle levels on anticoagulant therapy with rivaroxaban in nonvalvular AF. After administration of rivaroxaban, PMP levels were increased (median, [IQR] 35.7 [28.8-47.3] vs. 48.4 [30.9-82.8] cells/µL; P = 0.012), along with an increase in EMP levels (14.6 [10.0-18.6] vs. 18.3 [12.9-37.1] cells/µL, P < 0.001). In the multivariable regression analysis, the independent predictor of post-dose change in PMPs was statin therapy (HR −0.43; 95% CI −0.75,−0.10, P = 0.011). The post-dose change in EMPs was also predicted by statin therapy (HR −0.34; 95% CI −0.69, −0.01, P = 0.046). This study showed an increase in both EMPs and PMPs at the peak plasma concentration of rivaroxaban. Statins have promising potential in the prevention of rivaroxaban-related PMP and EMP release. The pro-thrombotic role of PMPs and EMPs during rivaroxaban therapy requires further study.

Systemic Immune-Inflammation Index Predicts 3-Month Functional Outcome in Acute Ischemic Stroke Patients Treated with Intravenous Thrombolysis

Background and Purpose

Systemic immune-inflammation index (SII), a novel inflammation index derived from counts of circulating platelets, neutrophils and lymphocytes, has been studied in developing incident cancer. However, the clinical value of SII in acute ischemic stroke (AIS) patients had not been further investigated. Therefore, we aimed to explore the association between SII and severity of stroke as well as 3-month outcome of AIS patients.

Methods

A total of 216 AIS patients receiving intravenous thrombolysis (IVT) and 875 healthy controls (HCs) were retrospectively recruited. Blood samples were collected within 24h after admission. Severity of stroke was assessed by the National Institute of Health stroke scale (NIHSS) scores on admission and poor 3-month functional outcome was defined as Modified Rankin Scale (mRS) > 2.

Results

SII levels in AIS patients were higher than in HCs. The cut-off value of SII is 545.14×10⁹/L. Patients with SII > 545.14×10⁹/L had higher NIHSS scores (median: 5 vs 9, p < 0.001), a positive correlation between SII and NIHSS was observed (rs = 0.305, p < 0.001). Multivariate logistic regression analyses showed that high SII was one of the independent risk factors for poor prognosis at 3 months of AIS patients (OR = 3.953, 95% CI = 1.702-9.179, p = 0.001). The addition of SII to the conventional prognostic model improved the reclassification (but not discrimination) of the functional outcome (net reclassification index 39.3%, p = 0.007).

Conclusion

SII is correlated with stroke severity at admission and can be a novel prognostic biomarker for AIS patients treated with IVT.

No obvious association exists between mean platelet volume and hypertension subtypes

Aims: To determine the association between mean platelet volume (MPV) and hypertension subtypes. Participants & results: 44,281 Chinese individuals were enrolled in this cross-sectional study. The mean blood pressure decreased with increasing MPV in females (p = 0.001) and increased MPV seemed to be a potential protective factor for isolated diastolic hypertension in models 1 and 2. The OR (CI) was 0.878 (0.789-0.976) for model 1 and 0.880 (0.789-0.981) for model 2 in males and 0.646 (0.495-0.841) for model 1 and 0.657 (0.503-0.858) for model 2 in females, when MPV was analyzed as a categorical variable. The OR (CI) was 0.947 (0.911-0.985) for Model 1 and 0.947 (0.910-0.985) for Model 2 in males, and 0.886 (0.807-0.973) for Model 1 and 0.892 (0.813-0.978) for Model 2 in females when MPV was analyzed as a continuous variable. However, the statistical difference of OR disappeared when we added blood-related covariates in Model 3. Conclusion: No obvious association exists between MPV and hypertension subtypes. Other blood parameters might have a greater impact on hypertension subtypes.

CD36+/CD61+ Microparticles Correlate with the Risk of Percutaneous Cardiac Interventions in Coronary Artery Disease Patients and the Effects of Ticagrelor

PURPOSE

The CD36 scavenger receptor is a mediator of both atherogenesis and thrombosis. We aimed to investigate the prognostic value of CD36+ microparticles (MPs) released from platelets for cardiovascular event presentation in coronary artery disease (CAD) patients and the effects of different antiplatelet drugs on MPs.

METHODS

A total of 101 aspirin-treated CAD patients, who were planned to undergo coronary angiography (CAG), were randomized to either a standard clopidogrel regimen or ticagrelor treatment. Total Annexin V-(AV)+ MPs, CD61+/AV+ MPs, and CD36+/CD61+/AV+ MPs were quantified by flow cytometry at baseline, before and immediately after the operation. The ADP-induced platelet inhibition rate was measured by thromboelastogram (TEG) examination 1 h before the operation.

RESULTS

The baseline levels of CD36+/CD61+/AV+ MPs were significantly increased in percutaneous coronary intervention (PCI) patients (n = 52) compared to no-PCI patients (n = 49) (p < 0.05). A ROC-curve clustered model for CD36+/CD61+/AV+ MPs at baseline predicted an increased risk of PCI [p = 0.009, AUC = 0.761 (95%CI: 0.601 to 0.922)]. Moreover, TEG examination showed that the preoperative proportion of CD36+/CD61+/AV+ MPs was significantly negatively correlated with R time and K time (r = - 0.236, p = 00.026; r = - 0.288, p = 0.006), and positively correlated with MA_ADP (r = 0.226, p = 0.045). Subgroup analysis of PCI group showed that the platelet inhibition rate of ticagrelor was significantly higher (66.05% ± 28.76% vs.31.01% ± 27.33%, p < 0.001), and the number of AV+ MPs, CD61+/AV+ MPs, and CD36+/CD61+/AV+ MPs before the operation was significantly lower than clopidogrel (p < 0.05, all).

CONCLUSION

The high levels of CD36+ MPs derived from activated platelets are related to an increased risk of PCI in CAD patients. Ticagrelor significantly reduced the number of CD61+/AV+ MPs and CD36+/CD61+/AV+ MPs. This trial registration number is ChiCTR1800014908 and the date of registration is 2018.05.01.

Stroke in SARS-CoV-2 Infection: A Pictorial Overview of the Pathoetiology

Since the early days of the pandemic, there have been several reports of cerebrovascular complications during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Numerous studies proposed a role for SARS-CoV-2 in igniting stroke. In this review, we focused on the pathoetiology of stroke among the infected patients. We pictured the results of the SARS-CoV-2 invasion to the central nervous system (CNS) via neuronal and hematogenous routes, in addition to viral infection in peripheral tissues with extensive crosstalk with the CNS. SARS-CoV-2 infection results in pro-inflammatory cytokine and chemokine release and activation of the immune system, COVID-19-associated coagulopathy, endotheliitis and vasculitis, hypoxia, imbalance in the renin-angiotensin system, and cardiovascular complications that all may lead to the incidence of stroke. Critically ill patients, those with pre-existing comorbidities and patients taking certain medications, such as drugs with elevated risk for arrhythmia or thrombophilia, are more susceptible to a stroke after SARS-CoV-2 infection. By providing a pictorial narrative review, we illustrated these associations in detail to broaden the scope of our understanding of stroke in SARS-CoV-2-infected patients. We also discussed the role of antiplatelets and anticoagulants for stroke prevention and the need for a personalized approach among patients with SARS-CoV-2 infection.

Association of platelet count and mean platelet volume (MPV) index with types of stroke

Background:

Stroke is known to be the third most prominent cause of death in the developing countries and the most common debilitating neurologic disease. This study aimed to investigate the association of platelet count (PC) and mean platelet volume (MPV) index with various stroke types.

Methods:

This cross-sectional study was carried out on patients over the age of 18 years who presented with signs and symptoms of the first acute stroke. Exclusion criteria were underlying chronic liver or renal disease and the time more than 6 hours from symptom initiation, hematological and infectious disorders in patients. After recording of demographic data, a complete blood cell count (CBC) test was performed.

Results:

From 150 patients, who enrolled in the study, 54.7% of patients were males. The initial brain CT scan was normal in 13 (8.7%) patients and showed evidence of brain infarction and intracranial hemorrhage in 84 (56%) and 53 (35.3%) patients respectively. Patients with intracranial hemorrhage had significantly higher mean of MPV index than the patients with normal brain-CT scan and patients with evidence of brain infarction (p<0.001).

Conclusion:

The MVP index can be a predictor of the type of hemorrhagic or ischemic finding in emergency CT scan in stroke patients. This relationship may help to better understand the physiopathologic role of platelets in the development of stroke (hemorrhagic or ischemic), but will not replace cerebral computed tomography to diagnose the type of stroke, or it may not initiate treatment for hemorrhagic stroke.

The Relationship between the Mean Platelet Volume and Carotid Atherosclerosis and Prognosis in Patients with Acute Cerebral Infarction

Objective

To investigate the relationship between mean platelet volume (MPV) level and carotid atherosclerosis and prognosis in patients with acute cerebral infarction. Methods. A retrospectively included 160 patients with acute cerebral infarction classified by TOAST classification as aortic atherosclerosis as the observation group. To analyze the relationship between MPV and carotid atherosclerosis, and use receiver operating characteristic (ROC) curves to analyze the role of MPV in predicting the prognosis of acute cerebral infarction in the observation group, grouping patients with different MPV by cut-off value, and analyze the differences in factors between the two groups of patients.

Results

MPV has a positive correlation with carotid atherosclerosis in patients with acute cerebral infarction. Multivariate logistic regression analysis revealed that increased MPV was an independent predictor of poor functional outcome in patients with acute cerebral infarction (Odds Ratio (OR): 6.152, 95% CI: 2.385-13.625, P < 0.01). ROC curve analysis showed that the area under the curve for MPV to predict poor prognosis was 0.868 (95% CI: 0.787-949, P < 0.01). The cutoff value, sensitivity, and specificity were 12.65, 76.2%, and 87.6%. Compared with patients with MPV < 12.65 at admission, patients with higher MPV levels (MPV ≥ 12.65) at admission have larger infarct size, more severe carotid artery stenosis, poor short-term prognosis, and higher mortality.

Conclusion

MPV level is closely related to the degree of carotid atherosclerosis in patients with acute cerebral infarction, and it is also an independent predictor of poor prognosis in patients with acute cerebral infarction at 3 months.

Endothelial and Leukocyte-Derived Microvesicles and Cardiovascular Risk After Stroke: PROSCIS-B

OBJECTIVE

To determine the role of circulating microvesicles (MV) on long-term cardiovascular outcomes after stroke, we measured them in patients with first-ever stroke with a 3-year follow-up.

METHODS

In the Prospective Cohort With Incident Stroke Berlin (PROSCIS-B), patients with first-ever ischemic stroke were followed up for 3 years. The primary combined endpoint consisted of recurrent stroke, myocardial infarction, and all-cause mortality. Citrate-blood levels of endothelial MV (EMV), leukocyte-derived MV (LMV), monocytic MV (MMV), and platelet-derived MV (PMV) were measured with flow cytometry. Kaplan-Meier curves and adjusted Cox proportional hazards models were used to estimate the effect of MV levels on the combined endpoint.

RESULTS

Five hundred seventy-one patients were recruited (median age 69 years, 39% female, median NIH Stroke Scale score 2, interquartile range 1-4), and 95 endpoints occurred. Patients with levels of EMV (adjusted hazard ratio [HR] 2.5, 95% confidence interval [CI] 1.2-4.9) or LMV (HR 3.1, 95% CI 1.4-6.8) in the highest quartile were more likely to experience an event than participants with lower levels with the lowest quartile used as the reference category. The association was less pronounced for PMV (HR 1.7, 95% CI 0.9-3.2) and absent for MMV (HR 1.1, 95% CI 0.6-1.8).

CONCLUSION

High levels of EMV and LMV after stroke were associated with worse cardiovascular outcome within 3 years. These results reinforce that endothelial dysfunction and vascular inflammation affect the long-term prognosis after stroke. EMV and LMV might play a role in risk prediction for stroke patients.

CLINICALTRIALSGOV IDENTIFIER

NCT01363856.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence of the effect of MV levels on subsequent stroke, myocardial infarction, or all-cause mortality in survivors of mild stroke.

Quantitation of phosphatidylserine-exposing platelets and platelet-derived microparticles in platelet products: A new strategy to improve efficacy of platelet transfusion

Platelet transfusion is an effective therapy to prevent or treat bleeding. Considering the different clinical purposes of transfusion, it is necessary to assess the quality of platelet products prepared in transfusion laboratories. So far, there is no solution to the problem of how best to do this. Here, we summarize the quantitation of phosphatidylserine (PS)-exposing platelets and platelet-derived microparticles (PMPs) in platelet products using previously reported data. Because PS promotes the assembly and enhances the activity of coagulation factors, classifying platelet products according to their concentrations of PS-exposing platelets and PMPs will improve the therapeutic treatment of transfusion recipients.

Liquid Biopsies: Microvesicles in Cardiovascular Disease

Significance: Circulating microvesicles (cMV) are small (0.1-1 μm) phospholipid-rich blebs released by almost all cell types, and their release increases with cell activation and injury, thus reflecting the state of the cell from which they are originated. Microvesicles (MV) are found in the bloodstream, and they affect the phenotype of recipient cells, after local or systemic circulation, by intercellular transfer of their molecular content. Recent Advances: Several studies suggest the use of cell-specific MV subpopulations as predictive biomarkers for cardiovascular diseases (CVDs) at different stages and degrees of severity. In this review, we describe the state of the art of cMV as noninvasive surrogate biomarkers of vascular injury and dysfunction correlated with poor clinical outcomes in CVD. Critical Issues: Despite the growing body of evidence supporting the importance of cMV as hallmarks of CVD and their utility as biomarkers of CVD, the specific roles of each phenotype of cMV in CVD burden and prognosis still remain to be elucidated and validated in large cohorts. In addition, the development of standardized and reproducible techniques is required to be used as biomarkers for disease progression in the clinical setting. Future Directions: A multipanel approach with specific cMV phenotypes, added to current biomarkers and scores, will undoubtedly provide unique prognostic information to stratify patients for appropriate therapy on the basis of their risk of atherothrombotic disease and will open a new research area as therapeutic targets for CVD. MV will add to the implementation of precision medicine by helping the cellular and molecular characterization of CVD patients.

Extracellular Vesicles in Acute Stroke Diagnostics

There is a large unmet need for fast and reliable diagnostics in several diseases. One such disease is stroke, where the efficacy of modern reperfusion therapies is highly time-dependent. Diagnosis of stroke and treatment initiation should be performed as soon as possible, and preferably before arrival at the stroke center. In recent years, several potential blood biomarkers for stroke have been evaluated, but without success. In this review, we will go into detail on the possibility of utilizing extracellular vesicles (EVs) released into the blood as novel biomarkers for stroke diagnostics. EVs are known to reflect the immediate state of the secreting cells and to be able to cross the blood–brain barrier, thus making them attractive as diagnostic biomarkers of brain diseases. Indeed, several studies have reported EV markers that enable differentiation between stroke patients and controls and, to a lesser extent, the ability to correctly classify the different stroke types. Most of the studies rely on the use of sophisticated and time-consuming methods to quantify specific subpopulations of the nanosized EVs. As these methods cannot be easily implemented in a rapid point of care (POC) test, technical developments followed by prospective clinical studies are needed.

Platelets Extracellular Vesicles as Regulators of Cancer Progression-An Updated Perspective

Extracellular vesicles (EVs) are a diverse group of membrane-bound structures secreted in physiological and pathological conditions by prokaryotic and eukaryotic cells. Their role in cell-to-cell communications has been discussed for more than two decades. More attention is paid to assess the impact of EVs in cancer. Numerous papers showed EVs as tumorigenesis regulators, by transferring their cargo molecules (miRNA, DNA, protein, cytokines, receptors, etc.) among cancer cells and cells in the tumor microenvironment. During platelet activation or apoptosis, platelet extracellular vesicles (PEVs) are formed. PEVs present a highly heterogeneous EVs population and are the most abundant EVs group in the circulatory system. The reason for the PEVs heterogeneity are their maternal activators, which is reflected on PEVs size and cargo. As PLTs role in cancer development is well-known, and PEVs are the most numerous EVs in blood, their feasible impact on cancer growth is strongly discussed. PEVs crosstalk could promote proliferation, change tumor microenvironment, favor metastasis formation. In many cases these functions were linked to the transfer into recipient cells specific cargo molecules from PEVs. The article reviews the PEVs biogenesis, cargo molecules, and their impact on the cancer progression.

The relationship between the platelet to leukocyte ratio and mechanical thrombectomy outcomes in acute ischemic stroke patients

BACKGROUND AND PURPOSE

The predictive effect of blood cell ratio on ischemic event has been widely confirmed. Whether PWR and PNR can assess the risk of endovascular treatment (EVT) is largely unclear. This study aimed to investigate the prognostic value of PNR and PWR in acute ischemic stroke patients treated with EVT.

METHODS

Poor functional outcome was defined as Modified Rankin Scale (mRS) of 3-6 at 3 months, Symptomatic intracranial hemorrhage (sICH) was diagnosed based on CT scan and classified according to the criterial of Heidelberg Bleeding Classification. Binary logistical regression was used to analyze the relationship of PWR, PNR with functional outcome and symptomatic intracranial hemorrhage (sICH).

RESULTS

Patients with good prognosis had higher PNR and PWR value (29 vs. 24, P=0.002) (22 vs. 19, P=0.009), a lower rate of sICH (2.9% vs. 24.9%, P<0.001). In model 1, the lower PNR significantly associated with poor functional outcome (OR, 0.48; 95% CI 0.26-0.88; P=0.018), and sICH (OR, 0.42; 95% CI 0.19-0.91; P=0.028). The lower PWR only significantly associated with poor prognosis (OR, 0.97; 95% CI 0.94-1.00; P=0.038), and had a trend relation with sICH (OR, 0.98; 95% CI 0.94-1.02; P=0.328). In model 2 lower PNR still significantly associated with poor functional outcome (OR, 0.53; 95% CI 0.29-0.99; P=0.047), but showed a trend for predicting sICH (OR, 0.56; 95% CI 0.25-1.25; P=0.158).

CONCLUSION

Platelet to leukocyte ratio may be use to assess the risk of functional outcome and sICH in patients with acute anterior circulation occlusion stroke undergoing endovascular treatment in real world China.

Internalization of microparticles by platelets is partially mediated by toll-like receptor 4 and enhances platelet thrombogenicity

BACKGROUND AND AIMS

Circulating platelet microparticles (PMP) are the most abundant in bloodstream, are highly procoagulant and contribute to cross-talk with inflammatory cells. The aim of the present study was to investigate the interactions of PMP with platelets and explore the involvement of toll-like receptor 4 (TLR-4).

METHODS

PMP were separated by ultracentrifugation of expired platelet concentrates and added to: i) washed platelets, to confirm uptake, by flow cytometry and confocal and transmission electron microscopy, ii) platelet rich plasma (PRP), to assess changes in platelet function due to uptake by aggregometry in response to ADP; and iii) whole blood, to evaluate heterotypic aggregate (HA) formation by flow cytometry. Moreover, whole blood previously enriched with platelets with internalized PMP was used to explore modifications in thromboelastometry parameters (ROTEM). The inhibitory action of anti-TLR-4 was investigated.

RESULTS

Confocal and ultrastructural microscopy studies revealed PMP internalization by platelets. Flow cytometry showed PMP-platelet association (p < 0.01 vs controls, at different PMP dilutions). PMP, at 1/20 dilution, increased HA (p < 0.05 vs controls), the percentage of maximal platelet aggregation to ADP (p < 0.05 vs controls), and accelerated clotting and clot formation times (p < 0.05 vs controls). Incubation of platelets with anti-TLR-4 prior to exposure to PMP reduced PMP-platelet association (p < 0.05 vs absence of the antibody), prevented HA formation, reduced maximal platelet aggregation and normalized ROTEM parameters.

CONCLUSIONS

Platelets exhibit internalization ability towards their own PMP, a process that potentiates their thrombogenicity and is partially mediated by the innate immunity receptor TLR-4.

Investigating the effect of age on platelet ultrastructure using transmission electron microscopy

In the present study, the age- and sex-related differences in platelet ultrastructure were investigated using transmission electron microscopy (TEM). A total of 15 healthy volunteers were grouped according to age, with 5 people in each of the following groups: young group (25-45 years), middle-aged group (46-65 years), and old-aged group (> 65 years). In the TEM micrographs, the internal components, specifically the α-granules, dense granules, and lysosomal granules, of 20 platelets were counted for each group. Two-way analysis of variance of age and sex variance was used to compare the results. The ultrastructure of the platelets in the old-aged group was observed to be quite different from those of the young and middle-aged groups. Specifically, with ageing, the platelet membrane becomes more irregular in shape and non-smooth, and multiple platelet membrane ruptures are observed. Furthermore, the pseudopodia and protuberances become more numerous and slender, and the number of α-granules is significantly reduced. These morphological changes indicate that ageing may affect the function of platelets, which in turn affects the efficacy of platelet concentrates. Thus, the effects of age should be considered when using platelet concentrates prepared from elderly autologous blood.

Extracellular Vesicles-Connecting Kingdoms

It is known that extracellular vesicles (EVs) are shed from cells of almost every type of cell or organism, showing their ubiquity in all empires of life. EVs are defined as naturally released particles from cells, delimited by a lipid bilayer, and cannot replicate. These nano- to micrometer scaled spheres shuttle a set of bioactive molecules. EVs are of great interest as vehicles for drug targeting and in fundamental biological research, but in vitro culture of animal cells usually achieves only small yields. The exploration of other biological kingdoms promises comprehensive knowledge on EVs broadening the opportunities for basic understanding and therapeutic use. Thus, plants might be sustainable biofactories producing nontoxic and highly specific nanovectors, whereas bacterial and fungal EVs are promising vaccines for the prevention of infectious diseases. Importantly, EVs from different eukaryotic and prokaryotic kingdoms are involved in many processes including host-pathogen interactions, spreading of resistances, and plant diseases. More extensive knowledge of inter-species and interkingdom regulation could provide advantages for preventing and treating pests and pathogens. In this review, we present a comprehensive overview of EVs derived from eukaryota and prokaryota and we discuss how better understanding of their intercommunication role provides opportunities for both fundamental and applied biology.

Platelet-Derived Extracellular Vesicles as Target of Antiplatelet Agents. What Is the Evidence?

Platelet-derived large extracellular vesicles (often referred to as microparticles in the field of cardiovascular disease) have been identified as effector in the atherothrombotic process, therefore representing a target of pharmacological intervention of potential interest. Despite that, limited evidence is so far available concerning the effects of antiplatelet agents on the release of platelet-derived extracellular vesicles. In the present narrative review, the mechanisms leading to vesiculation in platelets and the pathophysiological processes implicated will be discussed. This will be followed by a summary of the present evidence concerning the effects of antiplatelet agents under experimental conditions and in clinical settings.

Erythrocyte membrane affinity chromatography, solid-phase extraction and UPLC-QTOF-MS/MS to screen active ingredients of Buyang Huanwu decoction

Buyang Huanwu decoction (BHD) is a well-known traditional Chinese medicine that has long been used to treat ischemic brain damage which is associated with hemorheology. To screen active ingredients in BHD responsible for reducing blood viscosity by reducing red blood cell (RBC) lesions to treat ischemic stroke, a method involving RBC membrane binding and solid-phase extraction (SPE) was developed in this study. The components of BHD interacting with RBC were analyzed by mass spectrometry and four compounds, calycosin, paeoniflorin, 6-hydroxy behenol-3,6-di-O-glucoside and calycosin-7-O-β-d-glucoside, showed binding affinity to RBCs. An erythrocyte activity assay revealed that the identified ingredients promoted the activities of Na+-K+-ATPase, sialic acid and superoxide dismutase and reduced the content of cholesterol on the RBC membrane, suggesting a mechanism underlying their anti-erythrocyte aggregation activity. Based on these results, the RBC membrane binding assay combined with SPE and mass spectrometry is a novel and effective approach for screening potentially anti-erythrocyte lesion constituents in traditional Chinese medicines.

Insufficiency of positive airway pressure treatment on increased mean platelet volume: a prospective controlled study in patients with obstructive sleep apnea syndrome

BACKGROUND

To analyze the association between obstructive sleep apnea syndrome (OSAS) and some hematological variables such as mean platelet volume (MPV), platelet distribution width (PDW), and the impact of positive airway pressure (PAP) treatment on these parameters.

METHODS

The participants of the present prospective study consist of 36 OSAS patients diagnosed with polysomnography and recommended PAP treatment and 30 healthy members as the control group. Complete blood analyses were conducted to the patient group twice; before the initiation of the PAP treatment and 1 month after regular PAP use. The control group was administered a complete blood analyses only once. Patient and control group were compared in terms of various parameters such as MPV, PDW, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), white blood cell (WBC) values, and platelet counts.

RESULTS

MPV value of the patient group was before and after PAP treatment significantly higher than the control group (respectively; Z = 2.246; p = 0.025, and Z = 2.033; p = 0.042). However, there were no statistically significant differences in the values before and after PAP treatment in the patient group (Z = 0.727; p = 0.467). In terms of platelet numbers and PDW values, no significant differences were determined (p > 0.05).

CONCLUSION

MPV value was significantly elevated in OSAS patients. However, the 1 month of PAP treatment was insufficient in decreasing elevated MPV values.

Relationship between circulating microparticles and hypertension and other cardiac disease biomarkers in the elderly

Background

Microparticles are procoagulant membrane vesicles that play role in endothelium dysfunction pathogenesis and are increased in hypertension, acute/chronic vascular pathological events. Here; we aimed to compare MPs levels of hypertensive geriatric patients with healthy age-match-patients, discuss its availability as a cardiovascular biomarker and investigate its relationship with other inflammatory markers.

Methods

Forty seven hypertensive geriatric patients (M/F;15/32) and 47 healthy controls (M/F;19/28) were included in the study. MPs levels were examined functionally through thrombin generation test (TGT) parameters (MPS Lag time, MPS ETP, MPs Peak, MPS start Tail) and compared with CRP, N/L ratio, ALT, GGT, thrombocyte parameters. Decrease in MPS Lag time, increase in MPS ETS and MPs Peak elevation were accepted as tendency to coagulation which meant an increase in number and function of MPs.

Results

No significant difference was found between 2 groups for MPS tests (MPS Lag time, MPS ETP, MPs Peak, MPS start Tail). Platelet count was significantly higher in hypertensive patient group. There was a negative correlation between age and MPs Peak, MPS Lag time. There was a positive correlation between CRP and MPS ETP, MPs Peak values.

Conclusions

Our present findings might help to understand the hemostasis via TGT parameters, in the elderly. Contribution of MPs to thrombosis tendency seen with aging and increased number of circulating MPs caused by hypertensive endothelial dysfunction must be taken into consideration. MPs might be accepted as vascular inflammation and damage markers and used as follow up tools of medical treatment of vascular inflammation-related diseases.

Understanding Platelets in Infectious and Allergic Lung Diseases

Emerging evidence suggests that platelets, cytoplasmic fragments derived from megakaryocytes, can no longer be considered just as mediators in hemostasis and coagulation processes, but as key modulators of immunity. Platelets have received increasing attention as the emergence of new methodologies has allowed the characterization of their components and functions in the immune continuum. Platelet activation in infectious and allergic lung diseases has been well documented and associated with bacterial infections reproduced in several animal models of pulmonary bacterial infections. Direct interactions between platelets and bacteria have been associated with increased pulmonary platelet accumulation, whereas bacterial-derived toxins have also been reported to modulate platelet function. Recently, platelets have been found extravascular in the lungs of patients with asthma, and in animal models of allergic lung inflammation. Their ability to interact with immune and endothelial cells and secrete immune mediators makes them one attractive target for biomarker identification that will help characterize their contribution to lung diseases. Here, we present an original review of the last advances in the platelet field with a focus on the contribution of platelets to respiratory infections and allergic-mediated diseases.

Circulating microparticles as biomarkers of stroke: A focus on the value of endothelial- and platelet-derived microparticles

Stroke is one of the leading causes of mortality and disability worldwide. Numerous pathophysiological mechanisms involving blood vessels, coagulation and inflammation contribute to the vascular occlusion. Perturbations in these pathways can be detected by numerous methods including changes in endoplasmic membrane remodeling and rearrangement leading to the shedding of microparticles (MPs) from various cellular origins in the blood. MPs are small membrane-derived vesicles that are shed from nearly all cells in the body in resting state or upon stimulation. MPs act as biological messengers to transfer information to adjacent and distant cells thus regulating various biological processes. MPs may be important biomarkers and tools for the identification of the risk and diagnosis of cerebrovascular diseases. Endothelial activation and dysfunction and altered thrombotic responses are two of the main features predisposing to stroke. Endothelial MPs (EMPs) have been recognized as both biomarkers and effectors of endothelial cell activation and injury while platelet-derived MPs (PMPs) carry a strong procoagulant potential and are activated in thrombotic states. Therefore, we reviewed here the role of EMPs and PMPs as biomarkers of stroke. Most studies reported high circulating levels of EMPs and PMPs in addition to other cell origins in stroke patients and have been linked to stroke severity, the size of infarction, and prognosis. The identification and quantification of EMPs and PMPs may thus be useful for the diagnosis and management of stroke.

There Is Selective Increase in Pro-thrombotic Circulating Extracellular Vesicles in Acute Ischemic Stroke and Transient Ischemic Attack: A Study of Patients From the Middle East and Southeast Asia

Stroke attacks were found to be present at a younger age in patients from Southeast Asia (SE) and the Middle East (ME) resident in the state of Qatar. Extracellular vesicles (EVs), which are small membrane vesicles with pro-thrombotic properties, may contribute to the high risk of stroke in this population. Thus, total and cell-specific medium size EVs were counted by flow cytometry in platelet-free plasma from healthy volunteers and patients with transient ischemic attacks (TIA) and acute ischemic stroke (AIS) from SE and ME. Acutely, within 48 h of attacks, there was an increase in total endothelial EVs in TIA (6.73 ± 1.77; P = 0.0156; n = 21) and AIS (11.23 ± 1.95; P = 0.0007; n = 66) patients compared to controls (2.04 ± 0.78; n = 24). Similar increases were also evident in EVs originating from platelets, erythrocytes, granulocytes, and leukocytes. Compared to controls, there was also an increase in EVs derived from activated endothelial cells, platelets, granulocytes, leukocytes, and pro-coagulant EVs (Annexin V⁺) at 5 and 30-days following the acute events, while a decrease was observed in erythrocyte-derived EVs. This is the first study characterizing EVs in TIA and AIS patients from ME and SE showing an increase in EVs associated with endothelial and platelet cell activation, which may contribute to the elevated risk of stroke at a younger age in this population.

The mean platelet volume on admission predicts unfavorable stroke outcomes in patients treated with IV thrombolysis

Purpose

The role of biomarkers in the prediction of acute ischemic stroke (AIS) outcome or response to thrombolytic therapy (with recombinant tissue plasminogen activator [rt-PA]) remains limited. The aim of this study was to evaluate whether mean platelet volume (MPV) could predict short-term functional outcome in patients with AIS following rt-PA treatment.

Patients and methods

This was a retrospective analysis of 237 AIS patients (mean age 71.04±0.8 years, 50.6% women) consecutively admitted to a tertiary care center between 2011 and 2015.

Results

The mean MPV in the cohort was 9.8±0.35 fL (lowest tertile <7.29 fL, median 7.29–8.8 fL, and highest tertile >8.8 fL). Patients in the lowest tertile compared to median and highest tertiles were less often dependent (modified Rankin scale [mRS] ≥3) at admission (87.2% vs 96.1% and 96.1%, respectively, P=0.04) and less often had a poor stroke outcome (mRS 4–6) at discharge (28.2% vs 55.3% and 44.7%, P<0.01). However, there was no significant difference between tertiles with regard to AIS etiology, CT (Alberta Stroke Program Early CT) score, frequency of stroke due to large artery occlusion, risk of secondary hemorrhage, and early neurologic deterioration. Multivariable analysis after adjustment for confounders showed that patients in the second and third tertiles had a significantly higher risk of poor stroke outcome (OR =1.9, 95% CI =1.01–4), lack of early improvement (OR =1.91, 95% CI =1.05–3.47), lower chance of good outcome (mRS 0–2; OR =0.38, 95% CI =0.18–0.78), or minor stroke at discharge (OR =0.47, 95% CI =0.26–0.84). Receiver operating characteristic analysis for prediction of poor stroke outcome showed that the optimal cut-off point of MPV was 8.8 fL (area under the curve 0.586 [0.512–0.659], P=0.03) with a sensitivity of 82.7% and a specificity of 43.9%.

Conclusion

Disabling or fatal ischemic stroke in thrombolyzed patients was observed more often in patients with high admission MPV. The prognostic value of MPV was independent of other well-defined individual risk factors.

Altered profile of circulating microparticles in nonvalvular atrial fibrillation

Background

Nonvalvular atrial fibrillation (AF) is the most common cardiac arrhythmia, and it is associated with the prothrombotic state. Circulating microparticles (cMPs) are membrane vesicles that are shed from many cell types in response to cell activation and cell apoptosis. Several studies reported that cMPs may play a role in the hypercoagulable state that can be observed in patients with AF. The aim of this study was to determine the levels of total cMPs and characterize their cellular origins in AF patients.

Methods

Atotal of 66 AF patients and 33 healthy controls were enrolled. This study investigated total cMP levels and their cellular origin in AF patients using polychromatic flow cytometry.

Results

AF patients had significantly higher levels of total cMPs (median 36.38, interquartile range [IQR] 21.16‐68.50 × 10⁵ counts/mL vs median 15.21, IQR 9.91‐30.86 × 10⁵ counts/mL; P = 0.004), platelet‐derived MPs (PMPs) (median 10.61, IQR 6.55‐18.04 × 10⁵ counts/mL vs median 7.83, IQR 4.44‐10.26 × 10/mL; P = 0.009), and endothelial‐derived MPs (EMPs CD31+ CD41−) (median 2.94, IQR 1.78‐0.60 × 10⁵ counts/mL vs median 1.16, IQR 0.71‐2.30 × 10⁵ counts/mL; P = 0.001) than healthy controls after adjusting for potential confounders. Phosphatidylserine positive MP (PS + MP) levels were similar compared between AF patients and healthy controls.

Conclusion

The results of this study revealed a marked increase in total cMP levels, and evidence of elevated endothelial damage and platelet activation, as demonstrated by increased PMP and EMP levels, in AF patients. Additional study is needed to further elucidate the role of cMPs (PMPs and EMPs) in the pathophysiology of and the complications associated with AF.

Association of platelet-derived microvesicles and their phenotypes with carotid atherosclerosis and recurrent vascular events in patients after ischemic stroke

INTRODUCTION

Platelet-derived microvesicles (pMVs) exhibit procoagulant and proinflammatory properties and play a role in the development and progression of atherosclerosis. The study examined the association between the total number of pMVs and their phenotypes with carotid atherosclerosis and recurrent vascular events (VEs) in patients in the convalescent phase of ischemic stroke (IS).

MATERIALS AND METHODS

The study group consisted of 72 patients with IS secondary to large artery atherosclerosis (LAA) (n = 40) and small arteries occlusion (SAO) (n = 32) and 69 matched cardiovascular disease risk-factor (RF) controls. Total pMV number, defined as CD61+ microvesicles (MVs), and their phenotypes, defined as the surface expression of proinflammatory (CD40L, CD62P, CD31) and procoagulant (PS, PAC-1) markers, were characterized and quantified using flow cytometry. The mean common carotid intima-media thickness (CCA mean IMT), maximal common carotid IMT (CCA max IMT) and maximal bifurcation IMT (BIF max IMT) were measured bilaterally using B-mode, color Doppler ultrasonography. All study subjects were observed for one-year to establish the occurrence of VEs.

RESULTS

No differences in pMV parameters between LAA and SAO stroke subjects and between stroke subgroups and controls were found. Stroke patients with carotid atherosclerosis exhibited higher concentration of CD62P+/CD61+ and PAC-1+/CD61+ MVs compared to patients without the atherosclerosis. Positive associations between total number of pMVs, AnV+ MVs and AnV+/CD61+ MVs and atherosclerotic thickening of carotid intima-media in stroke patients were found. Elevated concentration of AnV+/CD61+, PAC-1+/CD61+, CD61P+/CD61+ and CD31+/CD61+ MVs, were revealed in stroke patients who suffered from recurrent VE in one-year follow-up period. Negative correlation of pMVs and CD62P+/CD61+ MVs concentration as well as percentage of total CD61+ in AnV+ population of MVs and time elapsed from IS in convalescent stroke subjects was revealed.

CONCLUSION

Our results confirm positive correlations between total pMV number, the number of PAC-1+/CD61+ and CD62+/CD61+ MVs and carotid atherosclerosis in stroke subjects. Some pMV parameters may exhibit a predictive value for the next VE in groups with a history of stroke. pMVs and some of their phenotypes decline over time elapsed from stroke in convalescent stroke subjects.

MicroRNAs as Diagnostic and Prognostic Biomarkers in Ischemic Stroke-A Comprehensive Review and Bioinformatic Analysis

Stroke is the second-most common cause of death worldwide. The pathophysiology of ischemic stroke (IS) is related to inflammation, atherosclerosis, blood coagulation, and platelet activation. MicroRNAs (miRNAs) play important roles in physiological and pathological processes of neurodegenerative diseases and progression of certain neurological diseases, such as IS. Several different miRNAs, and their target genes, are recognized to be involved in the pathophysiology of IS. The capacity of miRNAs to simultaneously regulate several target genes underlies their unique value as diagnostic and prognostic markers in IS. In this review, we focus on the role of miRNAs as diagnostic and prognostic biomarkers in IS. We discuss the most common and reliable detection methods available and promising tests currently under development. We also present original results from bioinformatic analyses of published results, identifying the ten most significant genes (HMGB1, YWHAZ, PIK3R1, STAT3, MAPK1, CBX5, CAPZB, THBS1, TNFRSF10B, RCOR1) associated with inflammation, blood coagulation, and platelet activation and targeted by miRNAs in IS. Additionally, we created miRNA-gene target interaction networks based on Gene Ontology (GO) information derived from publicly available databases. Among our most interesting findings, miR-19a-3p is the most widely modulated miRNA across all selected ontologies and might be proposed as novel biomarker in IS to be tested in future studies.