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Ezer E, Schrick D, Tőkés-Füzesi M, Papp I, Réger B, Molnár A, Ábrahám H, Koller A, Hársfalvi J, Kellermayer M, Molnár T. Gravity sedimentation reveals functionally and morphologically different platelets in human blood. Platelets 2024; 35:2298341. [PMID: 38186228 DOI: 10.1080/09537104.2023.2298341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 12/16/2023] [Indexed: 01/09/2024]
Abstract
In contrast to red blood cells, platelets float rather than sediment when a column of blood is placed in the gravitational field. By the analogy of erythrocyte sedimentation (ESR), it can be expressed with the platelet antisedimentation rate (PAR), which quantitates the difference in platelet count between the upper and lower halves of the blood column after 1 h of 1 g sedimentation. Venous blood samples from 21 healthy subjects were analyzed for PAR. After a 1-h sedimentation, the upper and lower fractions of blood samples were analyzed for platelet count, mean platelet volume (MPV), immature platelet fraction (IPF), and high-fluorescence IPF (H-IPF). The mechanisms behind platelet flotation were explored by further partitioning of the blood column, time-dependent measurements of platelet count and comparison with ESR. The structure and function of the platelets were assessed by electron microscopy (EM) and atomic force microscopy (AFM), and platelet aggregometry, respectively. Platelet antisedimentation is driven by density differences and facilitated by a size-exclusion mechanism caused by progressive erythrocyte sedimentation. The area under the curve (AUC) of the whole blood adenosine diphosphate (ADP) aggregation curves showed significant differences between the upper and lower samples (p < .005). AUC in the upper samples of 38% of healthy subjects exceeded the top of the normal range (53-122) suggesting that ascending platelets show an intensified ADP-induced aggregability ex vivo. H-IPF was significantly higher in the upper samples (p < .05). EM and AFM revealed that platelets in the upper samples were larger in volume and contained 1.6 times more alpha granules compared to platelets in the lower samples. Our results indicate that antisedimentation is able to differentiate platelet populations based on their structural and functional properties. Therefore, PAR may be a suitable laboratory parameter in various thromboinflammatory disorders.
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Affiliation(s)
- Erzsébet Ezer
- Department of Anesthesiology and Intensive Care, Medical School, University of Pecs, Pecs, Hungary
| | - Diana Schrick
- Department of Anesthesiology and Intensive Care, Medical School, University of Pecs, Pecs, Hungary
| | | | - István Papp
- Department of Laboratory Medicine, University of Pecs, Pecs, Hungary
| | - Barbara Réger
- Department of Laboratory Medicine, University of Pecs, Pecs, Hungary
| | - Abigél Molnár
- Department of Medical Biology and Central Electron Microscopic Laboratory, University of Pecs Medical School, Pecs, Hungary
| | - Hajnalka Ábrahám
- Department of Medical Biology and Central Electron Microscopic Laboratory, University of Pecs Medical School, Pecs, Hungary
| | - Akos Koller
- Department of Neurosurgery, Medical School, University of Pecs, Pecs, Hungary
- Department of Morphology and Physiology, Faculty of Health Sciences, Semmelweis University, Budapest, Hungary
| | - Jolán Hársfalvi
- Department of Biophysics and Radiation Biology, Faculty of Medicine,Semmelweis University, Budapest, Hungary
| | - Miklós Kellermayer
- Department of Biophysics and Radiation Biology, Faculty of Medicine,Semmelweis University, Budapest, Hungary
- HUN-REN Biophysical Virology Research Group, Semmelweis University, Budapest, Hungary
| | - Tihamér Molnár
- Department of Anesthesiology and Intensive Care, Medical School, University of Pecs, Pecs, Hungary
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Schrick D, Tőkés-Füzesi M, Réger B, Molnár T. Plasma Fibrinogen Independently Predicts Hypofibrinolysis in Severe COVID-19. Metabolites 2021; 11:826. [PMID: 34940584 PMCID: PMC8708410 DOI: 10.3390/metabo11120826] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 11/18/2021] [Accepted: 11/25/2021] [Indexed: 01/08/2023] Open
Abstract
High rates of thrombosis are present in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Deeper insight into the prothrombotic state is essential to provide the best thromboprophylaxis care. Here, we aimed to explore associations among platelet indices, conventional hemostasis parameters, and viscoelastometry data. This pilot study included patients with severe COVID-19 (n = 21) and age-matched controls (n = 21). Each patient received 100 mg aspirin therapy at the time of blood sampling. Total platelet count, high immature platelet fraction (H-IPF), fibrinogen, D-dimer, Activated Partial Thromboplastin Time, von Willebrand factor antigen and von Willebrand factor ristocetin cofactor activity, plasminogen, and alpha2-antiplasmin were measured. To monitor the aspirin therapy, a platelet function test from hirudin anticoagulated whole blood was performed using the ASPI test by Multiplate analyser. High on-aspirin platelet reactivity (n = 8) was defined with an AUC > 40 cut-off value by ASPI tests. In addition, in vitro viscoelastometric tests were carried out using a ClotPro analyser in COVID-associated thromboembolic events (n = 8) (p = 0.071) nor the survival rate (p = 0.854) showed associations with high on-aspirin platelet reactivity status. The platelet count (p = 0.03), all subjects. COVID-19 patients presented with higher levels of inflammatory markers, compared with the controls, along with evidence of hypercoagulability by ClotPro. H-IPF (%) was significantly higher among non-survivors (n = 18) compared to survivors (p = 0.011), and a negative correlation (p = 0.002) was found between H-IPF and plasminogen level in the total population. The platelet count was significantly higher among patients with high on-aspirin platelet reactivity (p = 0.03). Neither the ECA-A10 (p = 0.008), and ECA-MCF (p = 0.016) were significantly higher, while the tPA-CFT (p < 0.001) was significantly lower among patients with high on-aspirin platelet reactivity. However, only fibrinogen proved to be an independent predictor of hypofibrinolysis in severe COVID-19 patients. In conclusion, a faster developing, more solid clot formation was observed in aspirin 'non-responder' COVID-19 patients. Therefore, an individually tailored thromboprophylaxis is needed to prevent thrombotic complications, particularly in the hypofibrinolytic cluster.
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Affiliation(s)
- Diana Schrick
- Anesthesiology and Intensive Therapy, Clinical Centre, Medical School, University of Pécs, 7624 Pecs, Hungary;
| | - Margit Tőkés-Füzesi
- Department of Laboratory Medicine, Clinical Centre, Medical School, University of Pécs, 7624 Pecs, Hungary; (M.T.-F.); (B.R.)
| | - Barbara Réger
- Department of Laboratory Medicine, Clinical Centre, Medical School, University of Pécs, 7624 Pecs, Hungary; (M.T.-F.); (B.R.)
| | - Tihamér Molnár
- Anesthesiology and Intensive Therapy, Clinical Centre, Medical School, University of Pécs, 7624 Pecs, Hungary;
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