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International Journal of Molecular... Aug 2023The use of platelet-rich plasma (PRP) has gained increasing interest in recent decades. The platelet secretome contains a multitude of growth factors, cytokines,... (Review)
Review
The use of platelet-rich plasma (PRP) has gained increasing interest in recent decades. The platelet secretome contains a multitude of growth factors, cytokines, chemokines, and other biological biomolecules. In recent years, developments in the field of platelets have led to new insights, and attention has been focused on the platelets' released extracellular vesicles (EVs) and their role in intercellular communication. In this context, the aim of this review was to compile the current evidence on PRP-derived extracellular vesicles to identify the advantages and limitations fortheir use in the upcoming clinical applications. A total of 172 articles were identified during the systematic literature search through two databases (PubMed and Web of Science). Twenty publications met the inclusion criteria and were included in this review. According to the results, the use of PRP-EVs in the clinic is an emerging field of great interest that represents a promising therapeutic option, as their efficacy has been demonstrated in the majority of fields of applications included in this review. However, the lack of standardization along the procedures in both the field of PRP and the EVs makes it extremely challenging to compare results among studies. Establishing standardized conditions to ensure optimized and detailed protocols and define parameters such as the dose or the EV origin is therefore urgent. Further studies to elucidate the real contribution of EVs to PRP in terms of composition and functionality should also be performed. Nevertheless, research on the field provides promising results and a novel basis to deal with the regenerative medicine and drug delivery fields in the future.
Topics: Blood Platelets; Cell Communication; Extracellular Vesicles; Platelet-Rich Plasma; Regenerative Medicine
PubMed: 37685849
DOI: 10.3390/ijms241713043 -
Pediatric Emergency Care Aug 2018Balanced resuscitation of plasma, platelets, and red blood cells is now recognized as improving outcomes in traumatic bleeding in adults. The correct approach in... (Review)
Review
INTRODUCTION
Balanced resuscitation of plasma, platelets, and red blood cells is now recognized as improving outcomes in traumatic bleeding in adults. The correct approach in children has yet to be determined.
METHODS
We performed a systematic review of the literature into transfusion protocols in traumatic hemorrhage in children by conducting an article search of significant databases to identify relevant articles. Studies of interest included interventional trials with comparisons relating to the transfusion of blood including blood component therapy. The search identified 422 articles of interest, the abstracts of which were independently reviewed by 2 authors for inclusion in the trial. This revealed 35 articles, the full texts of which were reviewed. There were no randomized controlled trials and 4 nonrandomized trials with a further 21 articles that were deemed relevant. The data were insufficient for meta-analysis, and so a descriptive analysis was performed.
RESULTS
There were 4 main trials. Two trials were small (approximately 100 patients) nonrandomized trials into pediatric hemorrhage managed as per a massive transfusion protocol or at physician discretion. One was a retrospective analysis of pediatric trauma patients who received red blood cell transfusion with differing platelet ratios, and one was a trauma database review of component ratios in hemorrhaging children. All 4 trials found increased ratios had no effect on mortality.
DISCUSSION
As well as blood component therapy, adjunctive therapies used in the management of bleeding children are discussed. These include tranexamic acid, viscoelastic hemostatic assays, factor VIIa, and fibrinogen use.
CONCLUSIONS
There is little evidence for improved outcomes using component-based transfusion in a rigid 1:1:1 strategy in children. A goal-directed approach using viscoelastic hemostatic assay-guided treatment with early institution of tranexamic acid and fibrinogen replacement is considered the way forward.
Topics: Adult; Blood Transfusion; Child; Hemorrhage; Humans; Survival Rate; Wounds and Injuries
PubMed: 30080793
DOI: 10.1097/PEC.0000000000001570 -
Materials (Basel, Switzerland) Jan 2020Sinus augmentation can be performed with or without grafting biomaterials, and to date, there is no quality evidence regarding the augmentation of the sinus floor using... (Review)
Review
BACKGROUND
Sinus augmentation can be performed with or without grafting biomaterials, and to date, there is no quality evidence regarding the augmentation of the sinus floor using only platelet concentrates, which can improve the healing period and enhance bone regeneration by stimulating angiogenesis and bone formation. The main objective of this paper was to assess the effect of the sole use of platelet concentrates in sinus augmentation in terms of newly formed bone, augmented bone height, and clinical outcomes and to assess the additional beneficial effects of platelet-rich fibrin (PRF) in combination with other grafting biomaterials.
METHODS
A systematic review was conducted following Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Pooled analyses were performed with the Review Manager software.
RESULTS
For sinus elevation only using platelet concentrates, 11 studies met the inclusion criteria and were included for qualitative synthesis. Only one study was a clinical trial, which reported improved outcomes for the allograft group compared to the titanium-PRF (T-PRF) group. A total of 12 studies where PRF was used in addition to grafting biomaterials met eligibility criteria and were included in the review. Results from meta-analyses provided no additional beneficial effects of PRF in sinus augmentation in terms of bone height and percentage of soft tissue area. There was a statistically significant lower percentage of residual bone substitute material in the PRF (+) group compared to the PRF (-) group. The percentage of newly formed bone was slightly higher in the PRF (+) group, but this was not statistically significant.
CONCLUSION
There is no robust evidence to make firm conclusions regarding the beneficial effects of the sole use of platelet concentrates in sinus augmentation. However, studies have shown favorable outcomes regarding implant survival, bone gain, and bone height. The use of PRF with other grafting biomaterials appears to provide no additional beneficial effects in sinus lift procedures, but they may improve the healing period and bone formation. Well-conducted randomized clinical trials (RCTs) are necessary to confirm the available results to provide recommendations for the clinical practice.
PubMed: 32019255
DOI: 10.3390/ma13030622 -
British Journal of Clinical Pharmacology Nov 2014Platelets play an important role in cardiovascular disease, and β-blockers are often prescribed for cardiovascular disease prevention. β-Blockers may directly affect... (Meta-Analysis)
Meta-Analysis Review
AIMS
Platelets play an important role in cardiovascular disease, and β-blockers are often prescribed for cardiovascular disease prevention. β-Blockers may directly affect platelet aggregation, because β-adrenergic receptors are present on platelets. There is uncertainty about the existence and magnitude of an effect of β-blockers on platelet aggregation. The aim of this study was to perform a systematic review and meta-analysis of the effect of β-blockers on platelet aggregation.
METHODS
MEDLINE and EMBASE were searched until April 2014. Two reviewers independently performed data extraction and risk of bias assessment. Type of β-blocker, population, treatment duration and platelet aggregation were extracted. Standardized mean differences were calculated for each study and pooled in a random-effects meta-analysis.
RESULTS
We retrieved 31 studies (28 clinical trials and three observational studies). β-Blockers decreased platelet aggregation (standardized mean difference -0.54, 95% confidence interval -0.85 to -0.24, P < 0.0001). This corresponds to a reduction of 13% (95% confidence interval 8-17%). Nonselective lipophilic β-blockers decreased platelet aggregation more than selective nonlipophilic β-blockers.
CONCLUSIONS
Clinically used β-blockers significantly reduce platelet aggregation. Nonselective lipophilic β-blockers seem to reduce platelet aggregation more effectively than selective nonlipophilic β-blockers. These findings may help to explain why some β-blockers are more effective than others in preventing cardiovascular disease.
Topics: Adrenergic beta-Antagonists; Cardiovascular Diseases; Clinical Trials as Topic; Humans; Observational Studies as Topic; Platelet Aggregation
PubMed: 24730697
DOI: 10.1111/bcp.12404 -
European Journal of Vascular and... Mar 2022The aim was to enhance understanding of the role of platelet biomarkers in the pathogenesis of vascular events and risk stratifying patients with asymptomatic or... (Review)
Review
OBJECTIVE
The aim was to enhance understanding of the role of platelet biomarkers in the pathogenesis of vascular events and risk stratifying patients with asymptomatic or symptomatic atherosclerotic carotid stenosis.
DATA SOURCES
Systematic review conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.
REVIEW METHODS
A systematic review collated data from 1975 to 2020 on ex vivo platelet activation and platelet function/reactivity in patients with atherosclerotic carotid stenosis.
RESULTS
Forty-three studies met the inclusion criteria; the majority included patients on antiplatelet therapy. Five studies showed increased platelet biomarkers in patients with ≥ 30% asymptomatic carotid stenosis (ACS) vs. controls, with one neutral study. Preliminary data from one study suggested that quantification of "coated platelets" in combination with stenosis severity may aid risk stratification in patients with ≥ 50% - 99% ACS. Platelets were excessively activated in patients with ≥ 30% symptomatic carotid stenosis (SCS) vs. controls (≥ 11 positive studies and one neutral study). Antiplatelet-High on Treatment Platelet Reactivity (HTPR), previously called "antiplatelet resistance", was observed in 23% - 57% of patients on aspirin, with clopidogrel-HTPR in 25% - 100% of patients with ≥ 50% - 99% ACS. Aspirin-HTPR was noted in 9.5% - 64% and clopidogrel-HTPR in 0 - 83% of patients with ≥ 50% SCS. However, the data do not currently support the use of ex vivo platelet function/reactivity testing to tailor antiplatelet therapy outside of a research setting. Platelets are excessively activated (n = 5), with increased platelet counts (n = 3) in recently symptomatic vs. asymptomatic patients, including those without micro-emboli on transcranial Doppler (TCD) monitoring (n = 2). Most available studies (n = 7) showed that platelets become more reactive or activated following carotid endarterectomy or stenting, either as an acute phase response to intervention or peri-procedural treatment.
CONCLUSION
Platelets are excessively activated in patients with carotid stenosis vs. controls, in recently symptomatic vs. asymptomatic patients, and may become activated/hyper-reactive following carotid interventions despite commonly prescribed antiplatelet regimens. Further prospective multicentre studies are required to determine whether models combining clinical, neurovascular imaging, and platelet biomarker data can facilitate optimised antiplatelet therapy in individual patients with carotid stenosis.
Topics: Aspirin; Biomarkers; Blood Platelets; Carotid Stenosis; Humans; Platelet Aggregation Inhibitors; Stroke
PubMed: 35181225
DOI: 10.1016/j.ejvs.2021.10.045 -
Seminars in Thrombosis and Hemostasis Jul 2023Acute kidney injury (AKI) patients have increased bleeding risk, which could be partially due to acquired platelet dysfunction. We conducted a systematic review and a...
Acute kidney injury (AKI) patients have increased bleeding risk, which could be partially due to acquired platelet dysfunction. We conducted a systematic review and a cohort study to investigate platelet function and count in AKI and their association with AKI-related bleeding and mortality. Through a systematic literature search in PubMed and Embase, we identified 9 studies reporting platelet function and 56 studies reporting platelet count or platelet indices in AKI patients. Overall, platelet aggregation was reduced in AKI patients in nonintensive care unit (ICU) settings but not in ICU settings, except that reduced aggregation was associated with renal replacement therapy. Thrombocytopenia in AKI was frequent and often predictive of mortality. In our cohort study, we prospectively included 54 adult ICU patients who developed AKI within 24 hours of ICU admission and 33 non-AKI ICU controls. Platelet function was measured with light transmission aggregometry and flow cytometry. AKI patients bled more frequently than non-AKI patients ( = 0.04), and bleeding was associated with increased 30-day mortality in AKI ( = 0.02). However, platelet function was not different between AKI and non-AKI patients (aggregation: all > 0.52; flow cytometry: all > 0.07) and platelet function was not associated with bleeding in AKI. In conclusion, a reduced platelet count is frequent in AKI, but the literature on platelet function in AKI is sparse. In a cohort study, we demonstrated that patients with AKI within 24 hours of ICU admission exhibited increased bleeding tendency but this was not associated with reduced platelet function.
Topics: Adult; Humans; Cohort Studies; Intensive Care Units; Thrombocytopenia; Hospitalization; Acute Kidney Injury; Retrospective Studies
PubMed: 36174606
DOI: 10.1055/s-0042-1757167 -
Cellular Physiology and Biochemistry :... 2016The aim of this study was to elucidate the usefulness of platelet indices, mean platelet volume (MPV), platelet distribution width (PDW), and platelet count in diagnosis... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND/AIMS
The aim of this study was to elucidate the usefulness of platelet indices, mean platelet volume (MPV), platelet distribution width (PDW), and platelet count in diagnosis and monitoring of varicocele.
METHODS
The current study included 525 patients and 379 healthy subjects from five eligible studies. We performed meta-analysis of MPV, PDW, and platelet count and mean differences in these platelet indices between healthy subjects and varicocele patients.
RESULTS
The pooled MPVs were 8.168 fL (95% confidence interval [CI] 7.589 to 8.747) and 8.801 fL (95% CI 8.028 to 9.574) in healthy subjects and varicocele patients, respectively. The pooled mean difference in MPV between healthy subjects and varicocele patients was 0.834 fL in case-control studies (95% CI 0.195 to 1.473, P = 0.011). In both healthy subjects and varicocele patients, low platelet count subgroups showed higher MPV than high platelet count subgroups. The mean difference in MPV was higher in low platelet count subgroup. There was no significant difference in PDW between healthy subjects and varicocele patients.
CONCLUSION
Taken together, our data showed that platelet count was significantly lower in varicocele patients than in healthy subjects. Varicocele patients showed significantly higher MPV and lower platelet count than healthy subjects. MPV levels of patients differed according to platelet counts.
Topics: Blood Platelets; Humans; Male; Mean Platelet Volume; Platelet Count; Varicocele
PubMed: 27189836
DOI: 10.1159/000445579 -
The Cochrane Database of Systematic... Jan 2022In people with acute ischaemic stroke, platelets become activated and can cause blood clots to form and block an artery in the brain, resulting in damage to part of the... (Review)
Review
BACKGROUND
In people with acute ischaemic stroke, platelets become activated and can cause blood clots to form and block an artery in the brain, resulting in damage to part of the brain. Such damage gives rise to the symptoms of stroke. Antiplatelet therapy might reduce the volume of brain damaged by ischaemia and also reduce the risk of early recurrent ischaemic stroke, thereby reducing the risk of early death and improving long-term outcomes in survivors. However, antiplatelet therapy might also increase the risk of fatal or disabling intracranial haemorrhage.
OBJECTIVES
To assess the efficacy and safety of immediate oral antiplatelet therapy (i.e. started as soon as possible and no later than two weeks after stroke onset) in people with acute presumed ischaemic stroke.
SEARCH METHODS
We searched the Cochrane Stroke Group Trials Register, CENTRAL, MEDLINE Ovid, Embase Ovid, and two trials registers, and performed forward reference/cited reference searching in August 2020.
SELECTION CRITERIA
Randomised controlled trials (RCTs) comparing oral antiplatelet therapy (started within 14 days of the stroke) with control in people with definite or presumed ischaemic stroke.
DATA COLLECTION AND ANALYSIS
Two review authors independently applied the inclusion criteria and assessed trial quality. For the included trials, they extracted and cross-checked the data. They assessed risk of bias of each study using the Risk of Bias 1 (RoB1) tool and overall certainty of the evidence for each outcome using the GRADE approach.
MAIN RESULTS
We included 11 studies involving 42,226 participants. Three new trials have been added since the last update (743 participants). As per the previous version of this review, two trials testing aspirin 160 mg to 300 mg once daily, started within 48 hours of onset, contributed 96% of the data. The risk of bias was low. The maximum follow-up was six months. With treatment, there was a decrease in death or dependency at the end of follow-up (odds ratio (OR) 0.95, 95% confidence interval (CI) 0.91 to 0.99; 7 RCTs, 42,034 participants; moderate-certainty evidence). For every 1000 people treated with aspirin, 13 people would avoid death or dependency (number needed to treat for an additional beneficial outcome 79).
AUTHORS' CONCLUSIONS
Antiplatelet therapy with aspirin 160 mg to 300 mg daily, given orally (or by nasogastric tube or per rectum in people who cannot swallow) and started within 48 hours of onset of presumed ischaemic stroke, significantly decreased death and dependency, and reduced the risk of early recurrent ischaemic stroke without a major risk of early haemorrhagic complications; long-term outcomes were improved.
Topics: Aspirin; Brain Ischemia; Humans; Ischemic Stroke; Platelet Aggregation Inhibitors; Randomized Controlled Trials as Topic; Stroke
PubMed: 35028933
DOI: 10.1002/14651858.CD000029.pub4 -
Vox Sanguinis Jan 2023Platelet transfusions are used across multiple patient populations to prevent and correct bleeding. This scoping review aimed to map the currently available systematic... (Review)
Review
BACKGROUND AND OBJECTIVES
Platelet transfusions are used across multiple patient populations to prevent and correct bleeding. This scoping review aimed to map the currently available systematic reviews (SRs) and evidence-based guidelines in the field of platelet transfusion.
MATERIALS AND METHODS
A systematic literature search was conducted in seven databases for SRs on effectiveness (including dose and timing, transfusion trigger and ratio to other blood products), production modalities and decision support related to platelet transfusion. The following data were charted: methodological features of the SR, population, concept and context features, outcomes reported, study design and number of studies included. Results were synthesized in interactive evidence maps.
RESULTS
We identified 110 SRs. The majority focused on clinical effectiveness, including prophylactic or therapeutic transfusions compared to no platelet transfusion (34 SRs), prophylactic compared to therapeutic-only transfusion (8 SRs), dose, timing (11 SRs) and threshold for platelet transfusion (15 SRs) and the ratio of platelet transfusion to other blood products in massive transfusion (14 SRs). Furthermore, we included 34 SRs on decision support, of which 26 evaluated viscoelastic testing. Finally, we identified 22 SRs on platelet production modalities, including derivation (4 SRs), pathogen inactivation (6 SRs), leucodepletion (4 SRs) and ABO/human leucocyte antigen matching (5 SRs). The SRs were mapped according to concept and clinical context.
CONCLUSION
An interactive evidence map of SRs and evidence-based guidelines in the field of platelet transfusion has been developed and identified multiple reviews. This work serves as a tool for researchers looking for evidence gaps, thereby both supporting research and avoiding unnecessary duplication.
Topics: Humans; Hemorrhage; Platelet Transfusion; Thrombocytopenia
PubMed: 36454598
DOI: 10.1111/vox.13387 -
Intensive Care Medicine Jun 2020Despite increasing improvement in extracorporeal membrane oxygenation (ECMO) technology and knowledge, thrombocytopenia and impaired platelet function are usual findings... (Meta-Analysis)
Meta-Analysis Review
Despite increasing improvement in extracorporeal membrane oxygenation (ECMO) technology and knowledge, thrombocytopenia and impaired platelet function are usual findings in ECMO patients and the underlying mechanisms are only partially elucidated. The purpose of this meta-analysis and systematic review was to thoroughly summarize and discuss the existing knowledge of platelet profile in adult ECMO population. All studies meeting the inclusion criteria (detailed data about platelet count and function) were selected, after screening literature from July 1975 to August 2019. Twenty-one studies from 1.742 abstracts were selected. The pooled prevalence of thrombocytopenia in ECMO patients was 21% (95% CI 12.9-29.0; 14 studies). Thrombocytopenia prevalence was 25.4% (95% CI 10.6-61.4; 4 studies) in veno-venous ECMO, whereas it was 23.2% (95% CI 11.8-34.5; 6 studies) in veno-arterial ECMO. Heparin-induced thrombocytopenia prevalence was 3.7% (95% CI 1.8-5.5; 12 studies). Meta-regression revealed no significant association between ECMO duration and thrombocytopenia. Platelet function impairment was described in 7 studies. Impaired aggregation was shown in 5 studies, whereas loss of platelet receptors was found in one trial, and platelet activation was described in 2 studies. Platelet transfusions were needed in up to 50% of the patients. Red blood cell transfusions were administered from 46 to 100% of the ECMO patients. Bleeding events varied from 16.6 to 50.7%, although the cause and type of haemorrhage was not consistently reported. Thrombocytopenia and platelet dysfunction are common in ECMO patients, regardless the type of ECMO mode. The underlying mechanisms are multifactorial, and understanding and management are still limited. Further research to design appropriate strategies and protocols for its monitoring, management, or prevention should be matter of thorough investigations.
Topics: Adult; Blood Platelets; Extracorporeal Membrane Oxygenation; Hemorrhage; Humans; Platelet Count; Thrombocytopenia
PubMed: 32328725
DOI: 10.1007/s00134-020-06031-4