RESUMEN
The influence of chimeric antigen receptor T (CAR-T) cell therapy on platelet function in relapsed/refractory (R/R) multiple myeloma (MM) has not been thoroughly investigated. Our cohort comprised fifty MM patients treated with CAR-T cells. The mean platelet closure time (PCT) induced by collagen/adenosine diphosphate (CADP) in peripheral blood was significantly prolonged before lymphodepletion (195.24 ± 11.740 s) and notably reduced post-CAR-T cell therapy (128.02 ± 5.60 s), with a statistically significant improvement (67.22, 95% CI 46.91-87.53, P < 0.001). This post-treatment PCT was not significantly different from that of healthy controls (10.64, 95% CI 1.11-22.40, P > 0.05). Furthermore, a pronounced enhancement in PCT was observed in patients with a response greater than partial remission (PR) following CAR-T cell infusion compared to pre-treatment values (P < 0.001). An extended PCT was also associated with a less favorable remission status. In patients with cytokine release syndrome (CRS) grades 0-2, those with a PCT over 240.5 s exhibited a shorter progression-free survival (PFS), with median PFS times of 10.2 months for the PCT > 240.5 s group versus 22.0 months for the PCT ≤ 240.5 s group. Multivariate analysis revealed that a PCT value exceeding 240.5 s is an independent prognostic factor for overall survival (OS) in R/R MM patients after CAR-T cell therapy. The study demonstrates that CAR-T cell therapy enhances platelet function in R/R MM patients, and PCT emerges as a potential prognostic biomarker for the efficacy of CAR-T cell therapy.
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Plaquetas , Inmunoterapia Adoptiva , Mieloma Múltiple , Humanos , Mieloma Múltiple/terapia , Mieloma Múltiple/mortalidad , Mieloma Múltiple/patología , Masculino , Femenino , Persona de Mediana Edad , Anciano , Adulto , Resultado del Tratamiento , Receptores Quiméricos de Antígenos , Síndrome de Liberación de Citoquinas/terapia , Pruebas de Función PlaquetariaRESUMEN
Dual antiplatelet therapy (DAPT) use is the standard of practice after flow diversion (FD) for intracranial aneurysms (IAs). Yet, no consensus exists in the literature regarding the optimal regimen. Certain institutions utilize various platelet function testing (PFT) to assess patient responsiveness to DAPT. Clopidogrel is the most commonly prescribed drug during DAPT; however, up to 52% of patients can be non-responders, justifying PFT use. Additionally, prices vary significantly among antiplatelet drugs, often further complicated by insurance restrictions. We aimed to determine the most cost-effective strategy for deciding DAPT regimens for patients after IA treatment. A decision tree with Monte Carlo simulations was performed to simulate patients undergoing various three-month postoperative DAPT regimens. Patients were either universally administered aspirin alongside clopidogrel, ticagrelor, or prasugrel without PFT, or administered one of the former thienopyridine medications based on platelet reactivity unit (PRU) results after clopidogrel. Input data for the model were extracted from the current literature, and the willingness-to-pay threshold (WTP) was defined as $100,000 per QALY as per standard practice in the US. The baseline comparison was with universal clopidogrel DAPT without any PFT. Probabilistic and deterministic sensitivity analyses were performed to evaluate the robustness of the model. Utilizing PFT and switching clopidogrel to prasugrel if resistance is documented was the most cost-effective regimen compared to universal clopidogrel, with a base-case incremental cost-effectiveness ratio (ICER) of $-35,255 (cost $2,336.67, effectiveness 0.85). Performing PFT and switching clopidogrel to ticagrelor (ICER $-4,671; cost $2,995.06, effectiveness 0.84), universal prasugrel (ICER $5,553; cost $3,097.30, effectiveness 0.84), or universal ticagrelor (ICER $75,969; cost $3,801.36, effectiveness 0.84) were all more cost-effective than treating patients with universal clopidogrel (cost $3,041.77, effectiveness 0.83). These conclusions remain robust in probabilistic and deterministic sensitivity analyses. The most cost-effective strategy guiding DAPT after FD for IAs is to perform PFTs and switch clopidogrel to prasugrel if resistance is documented, alongside aspirin. The cost of PFT is strongly justified and recommended when deciding patient-specific DAPT regimens.
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Análisis Costo-Beneficio , Aneurisma Intracraneal , Inhibidores de Agregación Plaquetaria , Pruebas de Función Plaquetaria , Humanos , Aneurisma Intracraneal/cirugía , Aneurisma Intracraneal/tratamiento farmacológico , Inhibidores de Agregación Plaquetaria/uso terapéutico , Inhibidores de Agregación Plaquetaria/economía , Clopidogrel/uso terapéutico , Clopidogrel/economía , Clorhidrato de Prasugrel/uso terapéutico , Clorhidrato de Prasugrel/economía , Aspirina/uso terapéutico , Aspirina/economía , Ticagrelor/uso terapéutico , Terapia Antiplaquetaria Doble/métodosRESUMEN
Impedance aggregometry is an alternative to light transmission aggregometry that allows analysis of platelet function in whole blood samples. We hypothesized (1) impedance aggregometry would produce repeatable results, (2) inhibition of cyclooxygenase with aspirin would attenuate aggregation responses to collagen and abolish the aggregation response to arachidonic acid (AA), and (3) thromboxane receptor antagonism (terutroban) would attenuate the aggregation response to AA. Venous blood was obtained from 11 participants three times separated by at least 2 weeks. One sample followed 7-day-aspirin intervention (81 mg once daily; ASA), the others no intervention (control). Aggregation was induced using 1 µg/mL collagen ([col 1]), 5 µg/mL collagen ([col 5]), and 50 mM AA via impedance aggregometry to determine total aggregation (AUC) analyzed for intra-test repeatability, inter-test repeatability, intervention (ASA or control), and incubation (saline or terutroban). [col 1] showed high intra-test (p ≤ 0.03 visit 1 and 2) and inter-test repeatability (p < 0.01). [col 5] and AA showed intra- ([col 5] p < 0.01 visit 1 and 2; AA p < 0.001 visit 1 and 2) but not inter-test repeatability ([col 5] p = 0.48; AA p = 0.06). ASA attenuated AUC responses to [col 1] (p < 0.01), [col 5] (p = 0.03), and AA (p < 0.01). Terutroban attenuated AUC in response to AA (p < 0.01). [col 1] shows sufficient repeatability for longitudinal investigations of platelet function. [col 5] and AA may be used to investigate mechanisms of platelet function and metabolism at a single time point.
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Aspirina , Inhibidores de la Ciclooxigenasa , Impedancia Eléctrica , Agregación Plaquetaria , Pruebas de Función Plaquetaria , Propionatos , Receptores de Tromboxanos , Humanos , Agregación Plaquetaria/efectos de los fármacos , Masculino , Proyectos Piloto , Femenino , Inhibidores de la Ciclooxigenasa/farmacología , Aspirina/farmacología , Receptores de Tromboxanos/antagonistas & inhibidores , Receptores de Tromboxanos/metabolismo , Adulto , Pruebas de Función Plaquetaria/métodos , Propionatos/farmacología , Naftalenos/farmacología , Ácido Araquidónico/farmacología , Plaquetas/efectos de los fármacos , Plaquetas/metabolismo , Persona de Mediana Edad , Inhibidores de Agregación Plaquetaria/farmacología , Colágeno/farmacologíaRESUMEN
BACKGROUND: Although artificial and non-nutritive sweeteners are widely used and generally recognized as safe by the US and European Union regulatory agencies, there have been no clinical trials to assess either long-term cardiovascular disease risks or short-term cardiovascular disease-relevant phenotypes. Recent studies report that fasting plasma levels of erythritol, a commonly used sweetener, are clinically associated with heightened incident cardiovascular disease risks and enhance thrombosis potential in vitro and in animal models. Effects of dietary erythritol on thrombosis phenotypes in humans have not been examined. METHODS: Using a prospective interventional study design, we tested the impact of erythritol or glucose consumption on multiple indices of stimulus-dependent platelet responsiveness in healthy volunteers (n=10 per group). Erythritol plasma levels were quantified with liquid chromatography tandem mass spectrometry. Platelet function at baseline and following erythritol or glucose ingestion was assessed via both aggregometry and analysis of granule markers released. RESULTS: Dietary erythritol (30 g), but not glucose (30 g), lead to a >1000-fold increase in erythritol plasma concentration (6480 [5930-7300] versus 3.75 [3.35-3.87] µmol/L; P<0.0001) and exhibited acute enhancement of stimulus-dependent aggregation responses in all subjects, agonists, and doses examined. Erythritol ingestion also enhanced stimulus-dependent release of the platelet dense granule marker serotonin (P<0.0001 for TRAP6 [thrombin activator peptide 6] and P=0.004 for ADP) and the platelet α-granule marker CXCL4 (C-X-C motif ligand-4; P<0.0001 for TRAP6 and P=0.06 for ADP). In contrast, glucose ingestion triggered no significant increases in stimulus-dependent release of either serotonin or CXCL4. CONCLUSIONS: Ingestion of a typical quantity of the non-nutritive sweetener erythritol, but not glucose, enhances platelet reactivity in healthy volunteers, raising concerns that erythritol consumption may enhance thrombosis potential. Combined with recent large-scale clinical observational studies and mechanistic cell-based and animal model studies, the present findings suggest that discussion of whether erythritol should be reevaluated as a food additive with the Generally Recognized as Safe designation is warranted. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04731363.
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Plaquetas , Eritritol , Glucosa , Voluntarios Sanos , Agregación Plaquetaria , Trombosis , Humanos , Eritritol/sangre , Eritritol/administración & dosificación , Plaquetas/efectos de los fármacos , Plaquetas/metabolismo , Masculino , Trombosis/sangre , Trombosis/inducido químicamente , Trombosis/prevención & control , Estudios Prospectivos , Agregación Plaquetaria/efectos de los fármacos , Femenino , Adulto , Edulcorantes no Nutritivos/administración & dosificación , Edulcorantes no Nutritivos/efectos adversos , Adulto Joven , Factor Plaquetario 4/sangre , Espectrometría de Masas en Tándem , Persona de Mediana Edad , Serotonina/sangre , Edulcorantes/administración & dosificación , Pruebas de Función PlaquetariaRESUMEN
Clinical assessment of platelet activation by flow cytometry is useful in the characterization and diagnosis of platelet-specific disorders and as a measure of risk for thrombosis or bleeding. Platelets circulate in a resting, "unactivated" state, but when activated they undergo alterations in surface glycoprotein function and/or expression level, exposure of granule membrane proteins, and exposure of procoagulant phospholipids. Flow cytometry provides the means to detect these changes and, unlike other platelet tests, is appropriate for measuring platelet function in samples from patients with low platelet counts. The present review will focus on flow cytometric tests for platelet activation markers.
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Plaquetas , Citometría de Flujo , Activación Plaquetaria , Humanos , Pruebas de Función Plaquetaria , Trastornos de las Plaquetas Sanguíneas/diagnóstico , Trastornos de las Plaquetas Sanguíneas/sangre , Biomarcadores/sangreRESUMEN
Aggregometry plays a crucial role in both clinical diagnostics and research within hematology, serving as a fundamental tool for understanding platelet function and its implications in physiological and pathological processes. In research, aggregometry provides insights into platelet aggregation dynamics and aids in understanding the underlying mechanisms of hemostasis, thrombosis, and related disorders. Light transmission aggregometry (LTA) and lumi-aggregometry, as well as whole blood aggregometry, are commonly employed methods. While LTA and lumi-aggregometry allow for specific platelet function assessment under controlled conditions, whole blood aggregometry provides a more physiologically relevant approach by evaluating platelet aggregation within the context of whole blood. Although both methodologies offer unique advantages, whole blood aggregometry allows for preservation of the native cellular environment, simplicity, and potential for better clinical correlation. In a clinical setting, with human blood samples, protocols are established for both LTA and whole blood aggregometry as they are frequently used diagnostic tools. A protocol for LTA and lumi-aggregometry in murine models has been described; however, to date, there is no standardized protocol for whole blood aggregometry in murine models accessible to hematology researchers. This article aims to outline a simple, basic protocol for murine whole blood aggregometry, offering an alternative method to the commonly used LTA aggregometry in research settings. Standardizing whole blood aggregometry protocols in murine models could enhance experimental reliability and facilitate translational research efforts in hematology. © 2024 Wiley Periodicals LLC. Basic Protocol 1: Whole blood aggregometry in mice Support Protocol: Phenylhydrazine-induced anemia in wild-type mice Basic Protocol 2: Hematocrit percentage in mice.
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Agregación Plaquetaria , Pruebas de Función Plaquetaria , Animales , Ratones , Pruebas de Función Plaquetaria/métodos , Plaquetas/fisiología , Plaquetas/efectos de los fármacosRESUMEN
OBJECTIVES: Hydroxychloroquine (HCQ) has been shown to reduce thrombotic events in patients with SLE. However, the antiplatelet effects of HCQ are only supported by the platelet aggregation assay, which is a non-physiological test. The total thrombus-formation analysis system (T-TAS) is a microchip-based flow chamber system that mimics physiological conditions and allows for the quantitative analysis of thrombogenicity. The present study investigated the antiplatelet effects of HCQ using T-TAS. METHODS: This was a single-centre cross-sectional study on 57 patients with SLE. We measured the area under the pressure curve for 10 min (PL-AUC10) and the time to 10 kPa (T10) in patients with SLE using T-TAS and examined their relationships with the use of HCQ. PL-AUC10 and platelet aggregation were also measured at several HCQ concentrations using blood samples from healthy donors. RESULTS: PL-AUC10 was significantly lower in the HCQ/real body weight (RBW) ≥5 mg/kg group than in the <5 mg/kg group, while T10 was similar, indicating that HCQ inhibited overall thrombus formation rather than the initiation of thrombus formation. The antiplatelet effects of HCQ were initially detected at HCQ/RBW of approximately 4 mg/kg and reached a plateau at around 5.5 mg/kg. The administration of HCQ/RBW >4.6 mg/kg clearly exerted antiplatelet effects. Additionally, HCQ inhibited thrombus formation in T-TAS and the platelet aggregation response to epinephrine in a dose-dependent manner. CONCLUSIONS: We demonstrated the antiplatelet effects of HCQ under conditions simulating the physiological environment by using T-TAS and identified the range of doses at which HCQ exerted antiplatelet effects.
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Hidroxicloroquina , Lupus Eritematoso Sistémico , Inhibidores de Agregación Plaquetaria , Agregación Plaquetaria , Trombosis , Humanos , Hidroxicloroquina/uso terapéutico , Femenino , Lupus Eritematoso Sistémico/tratamiento farmacológico , Lupus Eritematoso Sistémico/complicaciones , Lupus Eritematoso Sistémico/sangre , Masculino , Agregación Plaquetaria/efectos de los fármacos , Adulto , Estudios Transversales , Inhibidores de Agregación Plaquetaria/uso terapéutico , Trombosis/prevención & control , Trombosis/etiología , Trombosis/tratamiento farmacológico , Persona de Mediana Edad , Adulto Joven , Pruebas de Función Plaquetaria/métodos , Antirreumáticos/uso terapéuticoRESUMEN
OBJECTIVE: The aim of this prospective study was to (1) objectively quantify the impact of sex on platelet function in patients with peripheral artery disease (PAD) taking antiplatelet and anticoagulant medications and (2) to develop and test a personalized, iterative algorithm that personalizes thromboprophylaxis that incorporates platelet function testing. BACKGROUND: Women with PAD have worse outcomes as compared with their male counterparts despite having lower risk factors. This health disparity may be mitigated by personalizing thromboprophylaxis regimens. METHODS: Patients undergoing revascularization were enrolled. Serial thromboelastography (TEG) and TEG with platelet mapping (TEG-PM) were performed up to 6 months postoperatively to determine objective coagulation profiles. In a subset of patients, the Antiplatelet Coagulation Exactness (ACE) algorithm was implemented, where patients were iteratively evaluated with TEG and given antiplatelet medications to maintain platelet inhibition at >29%. Statistical analysis was performed using unpaired t test, analysis of variance, and Fisher exact test. RESULTS: One hundred eighty-one patients met the study criteria. Fifty-eight (32%) patients were females and 123 (68%) were males. In the Aspirin cohort, females showed significantly greater clot strength as maximum amplitude - arachidonic acid (MA AA ) and significantly lower platelet inhibition than males: (37.26 vs 32.38, P <0.01) and (52.95% vs 61.65%, P <0.05), respectively. In the Clopidogrel cohort, females showed higher Maximum Amplitude - Adenosine Diphosphate (MA ADP ) (42.58 vs 40.35, P = not significant [NS]) compared with males. Females on dual antiplatelet therapy had higher MA ADP (39.74 vs 35.07, P =NS) and lower platelet inhibition (45.25% vs 54.99%, P= NS) than males. The incidence of thrombosis of the revascularized segment, defined as thrombotic event, was objectively identified on an arterial duplex. Women showed significantly higher thrombotic events than men (22.95% vs 10.57%, P< 0.05) on the same medication. In our pilot study, implementation of the ACE algorithm led to a significant decrease in the thrombosis rate (3%), including nonthrombotic events for females, versus the historic thrombotic rate (22%) from our institution. CONCLUSIONS: Women with PAD exhibited higher platelet reactivity, clot strength, and reduced platelet inhibition in response to antiplatelet therapy. The use of the ACE algorithm to tailor antiplatelet medication in patients with PAD post-revascularization, resulted in a significant decrease in thrombotic event rates. This may serve as an opportune way to mitigate outcome sex-specific disparities caused by inadequate thromboprophylaxis in women.
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Anticoagulantes , Enfermedad Arterial Periférica , Inhibidores de Agregación Plaquetaria , Tromboelastografía , Humanos , Femenino , Masculino , Inhibidores de Agregación Plaquetaria/uso terapéutico , Enfermedad Arterial Periférica/cirugía , Enfermedad Arterial Periférica/complicaciones , Anciano , Estudios Prospectivos , Anticoagulantes/uso terapéutico , Factores Sexuales , Persona de Mediana Edad , Algoritmos , Pruebas de Función Plaquetaria , Trombosis/prevención & control , Trombosis/etiologíaRESUMEN
This study aimed to establish in vitro hemodilution and resupplementation assays for obstetric hemorrhage in pregnancy-induced hypertension (PIH) and to monitor the coagulation function dynamically using a coagulation and platelet function analyzer. Forty-seven singleton pregnant women were divided into normal (n = 24) and PIH (n = 23) groups. Peripheral blood samples were used to construct the assays, and the activated clotting time (ACT), clotting rate (CR), and platelet function index (PF) were measured. The results showed that the baseline ACT was higher in the PIH group (p < 0.01). Hemodilution assays showed decreased ACT and increased CR and PF, with ACT changes significantly lower in the PIH group (p < 0.05). CR changed most in both groups at lower dilution ratios (35% to 50%), while ACT changed most at a higher dilution ratio (75%). In the resupplementation assay, ACT exhibited the most significant response. The analyzer effectively detected differences between pregnant women with and without PIH. Thus, we need to pay more attention to the changes of ACT in the actual clinical application to assess the coagulation status of parturients.
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Coagulación Sanguínea , Hipertensión Inducida en el Embarazo , Pruebas de Función Plaquetaria , Humanos , Femenino , Embarazo , Adulto , Hipertensión Inducida en el Embarazo/sangre , Hipertensión Inducida en el Embarazo/fisiopatología , Coagulación Sanguínea/fisiología , Pruebas de Coagulación Sanguínea , Hemorragia Posparto/sangre , Adulto JovenRESUMEN
Platelets play essential roles in the formation of blood clots by clumping with coagulation factors at the site of vascular injury to stop bleeding; therefore, a reduction in the platelet number or disorder in their function causes bleeding risk. In our research, we developed a method to assess platelet aggregation using an optical approach within a microfluidic chip's channel by evaluating the size of laser speckles. These speckles, associated with slowed blood flow in the microfluidic channel, had a baseline size of 28.54 ± 0.72 µm in whole blood. Removing platelets from the sample led to a notable decrease in speckle size to 27.04 ± 1.23 µm. Moreover, the addition of an ADP-containing agonist, which activates platelets, resulted in an increased speckle size of 32.89 ± 1.69 µm. This finding may provide a simple optical method via microfluidics that could be utilized to assess platelet functionality in diagnosing bleeding disorders and potentially in monitoring therapies that target platelets.
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Plaquetas , Agregación Plaquetaria , Plaquetas/efectos de los fármacos , Humanos , Agregación Plaquetaria/efectos de los fármacos , Pruebas de Función Plaquetaria/métodos , Pruebas de Función Plaquetaria/instrumentación , Dispositivos Laboratorio en un Chip , Técnicas Analíticas Microfluídicas/instrumentación , Técnicas Analíticas Microfluídicas/métodos , Microfluídica/métodos , Adenosina Difosfato/farmacologíaRESUMEN
The crucial role of platelets in hemostasis and their broad implications under various physiological conditions underscore the importance of accurate platelet-function testing. Platelets are key to clotting blood and healing wounds. Therefore, accurate diagnosis and management of platelet disorders are vital for patient care. This review outlines the significant advancements in platelet-function testing technologies, focusing on their working principles and the shift from traditional diagnostic methods to more innovative approaches. These improvements have deepened our understanding of platelet-related disorders and ushered in personalized treatment options. Despite challenges such as interpretation of complex data and the costs of new technologies, the potential for artificial-intelligence integration and the creation of wearable monitoring devices offers exciting future possibilities. This review underscores how these technological advances have enhanced the landscape of precision medicine and provided better diagnostic and treatment options for platelet-function disorders.
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Trastornos de las Plaquetas Sanguíneas , Plaquetas , Pruebas de Función Plaquetaria , Humanos , Plaquetas/metabolismo , Trastornos de las Plaquetas Sanguíneas/diagnóstico , Trastornos de las Plaquetas Sanguíneas/terapia , Trastornos de las Plaquetas Sanguíneas/sangre , Pruebas de Función Plaquetaria/métodos , Medicina de Precisión/métodos , HemostasisRESUMEN
BACKGROUND: Despite Antiplatelet therapy (APT), cardiovascular patients undergoing revascularisation remain at high risk for thrombotic events. Individual response to APT varies substantially, resulting in insufficient protection from thrombotic events due to high on-treatment platelet reactivity (HTPR) in ≤40% of patients. Individual variation in platelet response impairs APT guidance on a single patient level. Unfortunately, little is known about individual platelet response to APT over time, timing for accurate residual platelet reactivity measurement, or the optimal test to monitor residual platelet reactivity. AIMS: To investigate residual platelet reactivity variability over time in individual patients undergoing carotid endarterectomy (CEA) treated with clopidogrel. METHODS: Platelet reactivity was determined in patients undergoing CEA in a prospective, single-centre, observational study using the VerifyNow (change in turbidity from ADP-induced binding to fibrinogen-coated beads), the VASP assay (quantification of phosphorylation of vasodilator-stimulated phosphoprotein), and a flow-cytometry-based assay (PACT) at four perioperative time points. Genotyping identified slow (CYP2C19*2 and CYP2C19*3) and fast (CYP2C19*17) metabolisers. RESULTS: Between December 2017 and November 2019, 50 patients undergoing CEA were included. Platelet reactivity measured with the VerifyNow (p = < .001) and VASP (p = .029) changed over time, while the PACT did not. The VerifyNow identified patients changing HTRP status after surgery. The VASP identified patients changing HTPR status after eight weeks (p = .018). CYP2C19 genotyping identified 13 slow metabolisers. CONCLUSION: In patients undergoing CEA, perioperative platelet reactivity measurements fluctuate over time with little agreement between platelet reactivity assays. Consequently, HTPR status of individual patients measured with the VerifyNow and VASP assay changed over time. Therefore, generally used perioperative platelet reactivity measurements seem unreliable for adjusting perioperative APT strategy.
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Plaquetas , Clopidogrel , Endarterectomía Carotidea , Inhibidores de Agregación Plaquetaria , Humanos , Masculino , Femenino , Anciano , Proyectos Piloto , Plaquetas/metabolismo , Estudios Prospectivos , Inhibidores de Agregación Plaquetaria/uso terapéutico , Inhibidores de Agregación Plaquetaria/farmacología , Clopidogrel/uso terapéutico , Pruebas de Función Plaquetaria/métodos , Persona de Mediana Edad , Periodo Perioperatorio , Citocromo P-450 CYP2C19/genética , Citocromo P-450 CYP2C19/metabolismo , Procedimientos Quirúrgicos Vasculares , Activación Plaquetaria/efectos de los fármacos , Anciano de 80 o más Años , Moléculas de Adhesión Celular/metabolismo , Moléculas de Adhesión Celular/sangre , Proteínas de Microfilamentos/metabolismo , Proteínas de Microfilamentos/genética , Proteínas de Microfilamentos/sangreRESUMEN
BACKGROUND AND OBJECTIVES: The total thrombus-formation analysis system (T-TAS) can quantitatively analyse the contribution of platelets to haemostasis using reconstituted blood samples. However, it is unsuitable in cases with low platelet counts. We introduced a haemodilution (HD) chip with a shallow chamber depth, adapted to low platelet counts and high shear conditions (1500 s-1). MATERIALS AND METHODS: Blood samples were prepared by mixing red blood cell products, standard human plasma and platelet products; the final platelet count was 50 × 103/µL. Aggregation tests were performed by using the aggregation inducers collagen, adenosine diphosphate (ADP) and ristocetin. Samples with 2-, 4- and 9-day-old platelet products (N = 10) were evaluated. RESULTS: The HD chip enabled the stable analysis of the haemostatic function of all samples at a platelet count of 50 × 103/µL. Haemostatic function was correlated with ADP aggregation (time to 10 kPa [T10]: r = -0.53; area under the curve for 30 min: r = 0.40) and storage period (T10: r = 0.44). CONCLUSION: The HD chip-mounted T-TAS can stably analyse haemostatic function under low platelet counts and high shear conditions; this approach is expected to serve as a bridge to in vivo haemostatic tests with experimental animals.
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Plaquetas , Hemodilución , Humanos , Plaquetas/metabolismo , Trombosis/sangre , Agregación Plaquetaria , Recuento de Plaquetas , Dispositivos Laboratorio en un Chip , Hemostasis , Adenosina Difosfato , Pruebas de Función Plaquetaria/métodos , Pruebas de Función Plaquetaria/instrumentaciónRESUMEN
OBJECTIVES: Splenectomy during liver transplant can affect platelet function. In this study, our primary aim was to assess the perioperative platelet function by rotational thromboelastometry and the effects of splenectomy on platelet function. MATERIALS AND METHODS: We studied 40 consecutive liver transplant recipients with end-stage liver disease (50% as a result of hepatitis C). Patients with splenectomy were compared with patients without splenectomy (n = 20/group). Three platelet function parameters by rotational thromboelastometry were studied: platelet activation with arachidonic acid, platelet activation with adenosine diphosphate, and platelet activation with thrombin receptor-activating peptide 6. Patients were monitored perioperatively and until postoperative day 21. Heparin was infused for 2 days postoperatively (60-180 U/kg/day), followed by administration of subcutaneous low-molecular-weight heparin (40 mg/24 h) on postoperative days 2 and 3 and oral acetylsalicylic acid when platelet count was >50 × 103/µL. RESULTS: Liver disease contributed to low perioperative platelet count and function. Patients showed significant improvement by postoperative day 14 and day 21, particularly after splenectomy. Platelet count was significantly correlated with the 3 platelet function parameters by rotational thromboelastometry (P < .001). Acetyl salicylic acid was required earlier (postoperative day 3) for patients with splenectomy (8/20) but only affected the platelet function represented by platelet activation with arachidonic acid, whereas other platelet activation pathways were less affected. Patients received no transfusions of platelet units. CONCLUSIONS: End-stage liver disease significantly contributed to low platelet function and counts before transplant. Two weeks were required for recovery of patients posttransplant, with further enhancement by splenectomy. Some recipients showed recovery that exceeded the normal reference range, which warranted monitoring. Acetyl salicylic acid only affected 1 platelet activation receptor.
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Coagulación Sanguínea , Plaquetas , Enfermedad Hepática en Estado Terminal , Trasplante de Hígado , Valor Predictivo de las Pruebas , Esplenectomía , Tromboelastografía , Humanos , Trasplante de Hígado/efectos adversos , Masculino , Femenino , Persona de Mediana Edad , Esplenectomía/efectos adversos , Resultado del Tratamiento , Coagulación Sanguínea/efectos de los fármacos , Adulto , Enfermedad Hepática en Estado Terminal/cirugía , Enfermedad Hepática en Estado Terminal/diagnóstico , Enfermedad Hepática en Estado Terminal/sangre , Factores de Tiempo , Plaquetas/efectos de los fármacos , Activación Plaquetaria/efectos de los fármacos , Pruebas de Función Plaquetaria , Inhibidores de Agregación Plaquetaria/administración & dosificación , Anticoagulantes/administración & dosificación , Recuento de Plaquetas , Pruebas de Coagulación Sanguínea , Aspirina/administración & dosificación , Estudios ProspectivosRESUMEN
BACKGROUND: Enhanced platelet responses have been demonstrated in heartworm-infected (HWI) dogs; however, the cause and clinical implications of altered platelet function have not been fully elucidated. OBJECTIVE: This study evaluated platelet function in HWI dogs. METHODS: Anticoagulated whole blood collected from eight HWI and eight uninfected dogs was evaluated using turbidometric platelet aggregometry, a platelet function analyzer (PFA-100), a total thrombus analysis system (T-TAS), tissue factor-activated and tissue plasminogen activator modified thromboelastography (TF- and tPA-TEG), CBC, von Willebrand Factor activity, and fibrinogen concentrations. Platelet activation state and the presence of reticulated platelets were assessed via flow cytometric expression of P-selection (CD-62P) and thiazole orange staining. RESULTS: Platelet aggregation responses to adenosine diphosphate (ADP, 10 µM) or collagen (20 µg/mL), PFA-100 closure times, and T-TAS occlusion times did not differ between groups. TEG values TF-R, tPA-R, TF-K, and TF-LY60 were decreased (P = .025, P = .047, P = .038, P = .025) and TF-MA, tPA-MA, TF-G, tPA-G and TF-alpha angle were increased (P < .04) in HWI dogs. HWI dogs had higher fibrinogen concentrations (465.6 ± 161 mg/dL vs 284.5 ± 38 mg/dL, P = .008) and eosinophil counts (0.686 ± 0.27 × 103/µL vs 0.267 ± 0.20 × 103/µL, P = .003). There was no difference in hematocrit, activation state, or percent of reticulated platelets. Non-activated reticulated platelets exhibited higher CD62P expression compared with mature platelets. CONCLUSIONS: Chronic canine heartworm disease was accompanied by hypercoagulability, hyperfibrinogenemia, and decreased fibrinolysis. Enhanced platelet activation was not identified in this group of HWI dogs.
Asunto(s)
Coagulación Sanguínea , Dirofilariasis , Enfermedades de los Perros , Activación Plaquetaria , Animales , Perros , Enfermedades de los Perros/sangre , Enfermedades de los Perros/parasitología , Dirofilariasis/sangre , Femenino , Masculino , Pruebas de Función Plaquetaria/veterinaria , Plaquetas , Agregación Plaquetaria , Citometría de Flujo/veterinaria , Tromboelastografía/veterinaria , Dirofilaria immitisRESUMEN
PURPOSE OF REVIEW: Identification of a reliable discriminatory test to accurately stratify patient responses to antiplatelet therapy following coronary revascularization has become increasingly desirable to optimize therapeutic efficacy and safety. RECENT FINDINGS: The expansion of platelet function testing to include genotype assessment has been an evolutionary journey, initially fraught with confounding results. However, more recent and rigorous data analysis suggests that genotype testing- guided, tailored antiplatelet therapy may hold promise in optimizing treatment of patients after coronary intervention. Current evidence increasingly supports the use of genotype guided CYP2C19 testing to better match the post coronary intervention patient with the most efficacious and least risky antiplatelet inhibitor. The risk stratification of poor, intermediate, and good metabolizers of these drugs with such testing promises to yield clinical dividends in terms of morbidity, mortality and cost control, in this growing patient population.
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Citocromo P-450 CYP2C19 , Genotipo , Intervención Coronaria Percutánea , Inhibidores de Agregación Plaquetaria , Humanos , Citocromo P-450 CYP2C19/genética , Inhibidores de Agregación Plaquetaria/uso terapéutico , Pruebas de Función Plaquetaria , Clopidogrel/uso terapéutico , Enfermedad de la Arteria Coronaria/genética , Enfermedad de la Arteria Coronaria/tratamiento farmacológicoRESUMEN
BACKGROUND: Platelet radiolabeling with radioisotopes is currently used for human platelet recovery and survival studies. Biotinylation enables ex vivo post-transfusion platelet function testing. Whether platelet biotinylation itself affects platelet function is controversial. STUDY DESIGN AND METHODS: Platelet concentrates from healthy humans were stored for 6 days. Samples were obtained at 1 or 2 and 6 days, and platelets were labeled following a radiolabeling protocol using saline instead of radioactive indium-111 (sham radiolabeling [sham-RL]). Alternatively, a newly developed biotinylation protocol, a washing protocol, or an unmanipulated control sample were used. Platelet function was assessed by flow cytometry after stimulation with platelet agonists and labeling of platelets with platelet activation markers. To test whether platelets can be activated after transfusion, labeled platelets were transfused into nonobese diabetic/severe combined immunodeficiency mice, and samples were obtained 1 h after transfusion. RESULTS: The activation profile of biotinylated platelets was comparable to sham-RL platelets before transfusion except for significantly less α-degranulation and more phosphatidyl serine exposure on storage day 1/2. There was no significant difference between sham-RL and biotinylated platelets on storage day 6. Sham-RL and biotinylated platelets were significantly less activatable than washed and unmanipulated control platelets. After transfusion, the activation profile of biotinylated platelets was largely indistinguishable from unmanipulated ones. DISCUSSION: The decrease in activation level in biotinylated platelets we and others observed appears mainly due to the physical manipulation during the labeling process. In conclusion, biotinylated platelets allow for post-transfusion function assessment, a major advantage over radiolabeling.
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Biotinilación , Plaquetas , Conservación de la Sangre , Ratones SCID , Transfusión de Plaquetas , Humanos , Plaquetas/metabolismo , Animales , Ratones , Conservación de la Sangre/métodos , Ratones Endogámicos NOD , Activación Plaquetaria , Biotina/metabolismo , Biotina/química , Pruebas de Función Plaquetaria/métodosRESUMEN
Platelet functional activity was assessed in healthy volunteers (HV, n=92), patients with stable angina pectoris (SA, n=42) and acute coronary syndrome (ACS, n=73), treated with acetylsalicylic acid (ASA) + clopidogrel and ASA + ticagrelor, respectively. In all HV and patients we have compared parameters of platelet aggregation (maximum light transmission and velocity, Tmax and Vmax) and parameters, characterizing exposure of platelet activation markers, evaluated by flow cytometry. HV platelets were activated by 10 µM, 1 µM TRAP, and 20 µM, 5 µM, 2.5 µM ADP; patient platelets were activated by 10 µM TRAP and by 20 µM and 5 µM ADP. Strong and significant correlations between the aggregation and flow cytometry parameters (the r correlation coefficient from 0.4 up to >0.6) most frequently were registered in HV platelet during activation by 1 µM TRAP and in SA patients during platelet activation by 20 µM and 5 µM ADP. However, in many other cases these correlations were rather weak (r < 0.3) and sometimes statistically insignificant. In HV the differences in PAC-1 binding parameters between platelets activated by 10 µM TRAP (the strongest agonist) and all ADP concentrations were negligible (≤ 10%), while CD62P binding (at all ADP concentrations) and LTA parameters for (5 µM and 2.5 µM ADP) were significantly lower (by 40-60%). Antiplatelet therapy in patients decreased all parameters as compared to HV, but to varying extents. For 10 µM TRAP the MFI index for PAC-1 binding (40-50% decrease) and for both ADP concentrations the Tmax values (60-85% decrease) appeared to be the most sensitive in comparison with the other parameters that decreased to a lesser extent. The data obtained indicate a possibility of inconsistency between different LTA and flow cytometry parameters in assessing platelet activity and efficacy of antiplatelet drugs.
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Síndrome Coronario Agudo , Aspirina , Plaquetas , Clopidogrel , Citometría de Flujo , Inhibidores de Agregación Plaquetaria , Agregación Plaquetaria , Humanos , Inhibidores de Agregación Plaquetaria/farmacología , Agregación Plaquetaria/efectos de los fármacos , Masculino , Aspirina/farmacología , Aspirina/uso terapéutico , Femenino , Plaquetas/efectos de los fármacos , Plaquetas/metabolismo , Persona de Mediana Edad , Clopidogrel/farmacología , Anciano , Síndrome Coronario Agudo/tratamiento farmacológico , Síndrome Coronario Agudo/sangre , Adulto , Ticagrelor/farmacología , Ticagrelor/uso terapéutico , Pruebas de Función Plaquetaria/métodos , Activación Plaquetaria/efectos de los fármacos , Angina Estable/tratamiento farmacológico , Angina Estable/sangre , Adenosina Difosfato/farmacologíaAsunto(s)
Intervención Coronaria Percutánea , Humanos , Medición de Riesgo/métodos , Intervención Coronaria Percutánea/efectos adversos , Sistemas de Atención de Punto , Pruebas en el Punto de Atención , Pruebas de Función Plaquetaria/métodos , Activación Plaquetaria/fisiología , Inhibidores de Agregación Plaquetaria/uso terapéuticoRESUMEN
While there are various aspects of platelet biology that can be studied in the lab (i.e. adhesion, degranulation, integrin activation), the master test for platelet function is that which gives a measure of the platelet aggregation capacity upon stimulation with an agonist. Platelet function testing is necessary for the diagnosis of platelet disorders and the monitoring of patients receiving anti-platelet treatments. Furthermore, it becomes relevant in the quality control of platelet concentrates for transfusion purposes, especially considering the global concern about long term storage, other forms of storage (i.e. cryopreservation, lyophilization), and the impact of Pathogen Reduction Treatments (PRTs) on platelet performance upon transfusion. However, it has been acknowledged as technically difficult and demanding, since a fine platelet function test must be carried out under specific conditions. Still, there might be occasions that preclude the platelet function testing abiding to the gold standard requirements, thus, leaving us with the necessity to redefine which variables may condition or limit the analysis of platelet function testing. In the present manuscript, we test different variables (such as the anticoagulant used or the time elapsed since extraction) and the possibility to reconstitute blood prior to platelet function analysis. This study aims to provide windows of action at the diagnostics lab, especially when not all of the recommended procedures and conditions can be followed: for example, when a sample is sent from a long distance, when there is a limitation on blood extraction volume or when certain parameters (platelet count) preclude reliable test results.