Use of the Platelet Reactivity Index by Grotemeyer, Platelet Function Analyzer, and Retention Test Homburg To Monitor Therapy with Antiplatelet Drugs

Koscielny, Jürgen; Aslan, Tunay; Meyer, Oliver; Kiesewetter, H.; Jung, F.; Mrowietz, C.; Latza, Reinhard

doi:10.1055/s-2005-916682

Cited by 9 publications

(12 citation statements)

References 11 publications

(26 reference statements)

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“…It is used for quantitative determination of circulating platelet aggregates in vivo and for calculating platelet aggregation ratio (PAR). PAR values and its derivates have been used successfully to identify the effectiveness of antiplatelet drugs and their optimum dosage in patients suffering from stroke [1,7,8,9, 17, 18]. However, we failed to find any study using PAR as a predictive factor in differential diagnosis of ischemic cerebrovascular diseases.…”

Section: Introductioncontrasting

confidence: 41%

“…The automatic coulter counters can be found in most hospitals. Koscielny et al [8] reported that PAR values could be correlated with values received from the retention test Homburg (RT-H) and the platelet function analyzer (PFA-100).…”

Section: Discussionmentioning

confidence: 99%

“…Therefore, several studies have focused on platelet functions and its aggregation [1,2,3,4,5,6,7,8,9,10]. Platelet hyperreactivity and the presence of circulating activated platelets have been reported in patients with ischemic cerebrovascular diseases [1, 4,11,12,13,14].…”

Section: Introductionmentioning

confidence: 99%

“…Various methods have been used for determining platelet aggregates [5,6,7,8,9,17,18,19]. One of them is Wu and Hoak’s [20].…”

Section: Introductionmentioning

confidence: 99%

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Could Platelet Aggregation Ratio Be an Indicator for Differential Diagnosis of Transient Ischemic Attack and Cerebral Ischemic Stroke?

Tatlı¹,

Güzel²,

Akyüz

et al. 2006

Cerebrovasc Dis

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Background: Platelet aggregation plays an important role in the pathogenesis of thromboembolic cerebrovascular disease. Platelet aggregation ratio (PAR) and its derivates have been used successfully to identify the effectiveness of antiplatelet agents and their optimum dosage in patients suffering from stroke. However, we failed to find any study using PAR as a predictive factor in differential diagnosis of ischemic cerebrovascular diseases. In this study, we aimed to investigate PAR in patients with acute ischemic stroke and transient ischemic attack (TIA), comparing their neuroradiological features, and whether PAR values could be an indicator for differential diagnosis of TIA and cerebral ischemic stroke. Methods: The study consisted of 75 adult patients who were admitted with suspected stroke and 25 control healthy individuals. All patients were diagnosed with acute ischemic stroke or TIA and the diagnoses were confirmed by clinical examination and computed tomography (CT). The stroke group consisted of 45, and the TIA group of 30 consecutive patients. The patients included in this study had noncardioembolic stroke. PAR values were measured on admission in all groups, according to the modified method of Wu and Hoak. The statistical significance of differences was evaluated using one-way ANOVA, the unpaired Student t test and the Bonferroni and Tamhane post hoc tests.Results:Differences in PARs between the control and TIA groups, control and stroke groups and stroke and TIA groups were significant (p < 0.001). Nevertheless, in each group, differences between genders were not statistically significant. Initial CT scan demonstrated early infarction sign in 26 stroke patients (57%); however, in 19 stroke patients, it was not detected. Differences in PARs between TIA and stroke patients, whose initial CT scan findings were negative, were found to be significant. However, differences in PARs between CT negative stroke patients and positive stroke patients were not significant. Conclusion: We believe that the use of PAR values in the assessment of acute ischemic stroke and TIA could open up a new perspective in the management of such patients. In differential diagnosis, PAR values have to combine with neurological examination and CT scan signs. The current test is not able to differentiate vascular occlusive diseases in other organs from vascular occlusive problems in the brain. Further study is needed to determine the sensitivity and specificity of this test in all patients and to confirm the prognostic value in stroke patients.

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Section: Introductioncontrasting

confidence: 41%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…Various methods have been used for determining platelet aggregates [5,6,7,8,9,17,18,19]. One of them is Wu and Hoak’s [20].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Could Platelet Aggregation Ratio Be an Indicator for Differential Diagnosis of Transient Ischemic Attack and Cerebral Ischemic Stroke?

Tatlı¹,

Güzel²,

Akyüz

et al. 2006

Cerebrovasc Dis

View full text Add to dashboard Cite

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“…The spontaneous hyperaggregability of platelets is described to be a risk factor for major adverse cardiovascular events and occlusion syndromes [1,2,15,28,38]. On the other hand, there are a lot of diseases associated with non-functional or partly non-functional platelets, which need to be tested using different activators (adenosine 5 -diphosphate, arachidonic acid, thrombin, collagen, ristocetin, etc.)…”

Section: Introductionmentioning

confidence: 99%

Changes in platelet morphology and function during 24 hours of storage

Braune

Walter

Schulze

et al. 2014

Clinical Hemorheology and Microcirculation

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For in vitro studies assessing the interaction of platelets with implant materials, common and standardized protocols for the preparation of platelet rich plasma (PRP) are lacking, which may lead to non-matching results due to the diversity of applied protocols. Particularly, the aging of platelets during prolonged preparation and storage times is discussed to lead to an underestimation of the material thrombogenicity. Here, we study the influence of whole blood-and PRP-storage times on changes in platelet morphology and function.Blood from apparently healthy subjects was collected according to a standardized protocol and examined immediately after blood collection, four hours and twenty four hours later. The capability of platelets to adhere and form stable aggregates (PFA100, closure time) was examined in sodium citrate anticoagulated whole blood (WB) using the agonists equine type I collagen and epinephrine bitartrate (collagen/epinephrine) as well as equine type I collagen and adenosine-5 -diphosphate (collagen/ADP). Circulating platelets were quantified at each time point. Morphology of platelets and platelet aggregates were visualized microscopically and measured using an electric field multi-channel counting system (CASY). The percentage of activated platelets was assessed by means of P-selectin (CD62P) expression of circulating platelets. Furthermore, platelet factor 4 (PF4) release was measured in platelet poor plasma (PPP) at each time point.Whole blood PFA100 closure times increased after stimulation with collagen/ADP and collagen/epinephrine. Twenty four hours after blood collection, both parameters were prolonged pathologically above the upper limit of the reference range. Numbers of circulating platelets, measured in PRP, decreased after four hours, but no longer after twenty four hours. Mean platelet volumes (MPV) and platelet large cell ratios (P-LCR, 12 fL -40 fL) decreased over time. Immediately after blood collection, no debris or platelet aggregates could be visualized microscopically. After four hours, first debris and very small aggregates occurred. After 24 hours, platelet aggregates and also debris progressively increased. In accordance to this, the CASY system revealed an increase of platelet aggregates (up to 90 m diameter) with increasing storage time. The percentage of CD62P positive platelets and PF4 increased significantly with storage time in resting PRP. When soluble ADP was added to stored PRP samples, the number of activatable platelets decreased significantly over storage time.The present study reveals the importance of a consequent standardization in the preparation of WB and PRP. Platelet morphology and function, particularly platelet reactivity to adherent or soluble agonists in their surrounding milieu, changed rapidly outside the vascular system. This knowledge is of crucial interest, particularly in the field of biomaterial development for cardiovascular applications, and may help to define common standards in the in vitro hemocompatibility testing of biomaterials.

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Adhesion and activation of platelets from subjects with coronary artery disease and apparently healthy individuals on biomaterials

et al. 2015

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On the basis of the clinical studies in patients with coronary artery disease (CAD) presenting an increased percentage of activated platelets, we hypothesized that hemocompatibility testing utilizing platelets from healthy individuals may result in an underestimation of the materials' thrombogenicity. Therefore, we investigated the interaction of polymer-based biomaterials with platelets from CAD patients in comparison to platelets from apparently healthy individuals. In vitro static thrombogenicity tests revealed that adherent platelet densities and total platelet covered areas were significantly increased for the low (polydimethylsiloxane, PDMS) and medium (Collagen) thrombogenic surfaces in the CAD group compared to the healthy subjects group. The area per single platelet-indicating the spreading and activation of the platelets-was markedly increased on PDMS treated with PRP from CAD subjects. This could not be observed for collagen or polytetrafluoroethylene (PTFE). For the latter material, platelet adhesion and surface coverage did not differ between the two groups. Irrespective of the substrate, the variability of these parameters was increased for CAD patients compared to healthy subjects. This indicates a higher reactivity of platelets from CAD patients compared to the healthy individuals. Our results revealed, for the first time, that utilizing platelets from apparently healthy donors bears the risk of underestimating the thrombogenicity of polymer-based biomaterials.

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Use of the Platelet Reactivity Index by Grotemeyer, Platelet Function Analyzer, and Retention Test Homburg To Monitor Therapy with Antiplatelet Drugs

Cited by 9 publications

References 11 publications

Could Platelet Aggregation Ratio Be an Indicator for Differential Diagnosis of Transient Ischemic Attack and Cerebral Ischemic Stroke?

Could Platelet Aggregation Ratio Be an Indicator for Differential Diagnosis of Transient Ischemic Attack and Cerebral Ischemic Stroke?

Changes in platelet morphology and function during 24 hours of storage

Adhesion and activation of platelets from subjects with coronary artery disease and apparently healthy individuals on biomaterials

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