RESUMEN
OBJECTIVE: The aim of this study was to review the role of activated carbon (AC) in eliminating the interference of rivaroxaban in the detection of lupus anticoagulants (LAs). METHODS: Normal pooled plasma was obtained as group N1, group N2 took 1 mL plasma from N1 and added AC, group N3 was prepared by mixing normal plasma with rivaroxaban, and group N3 was treated with AC according to our procedure, as group N4. Plasma from 22 patients was collected before and 6-12 h after rivaroxaban therapy, described as group P1 and group P2, respectively, and 1 mL plasma was taken from group P2 and treated with AC, as group P3. Anti-Xa and diluted Russell's viper venom time (dRVVT)/silica clotting time (SCT) index in each group were measured and compared. RESULTS: Rivaroxaban concentrations and anti-Xa had high intercorrelations in group N3, and the levels of anti-Xa and dRVVT/SCT index had high intercorrelations. After treatment with AC, influence of rivaroxaban was removed, with LA and coagulation factor assays not influenced. Rivaroxaban administration could affect LA assay results in patients, with all LA results increased. After treatment with AC, results of anti-Xa and LA tests recovered to the level before rivaroxaban therapy. CONCLUSIONS: We proposed a reference procedure for the LA detection of patients using rivaroxaban by AC, and activated carbon was proven to be a simple product to eliminate the interference of rivaroxaban.
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Inhibidor de Coagulación del Lupus , Rivaroxabán , Pruebas de Coagulación Sanguínea/métodos , Carbón Orgánico , Reacciones Falso Positivas , Humanos , Tiempo de Tromboplastina Parcial , Tiempo de Protrombina , Rivaroxabán/uso terapéuticoRESUMEN
BACKGROUND: The acute vascular disease deep vein thrombosis (DVT) requires oral anticoagulants to prevent progression. Monitoring therapeutic efficacy of direct oral anticoagulants (DOAC), including rivaroxaban, is problematic as no reliable test is available. Advances in rheometry have led to the development of a functional coagulation biomarker using Gel Point (GP) analysis which assesses clot structure formation. The biomarker measures incipient clot formation time (TGP) and quantifies fibrin clot structure in terms of fractal dimension (df). OBJECTIVE: This study aimed to investigate clot structure formation in first time DVT and the effect of rivaroxaban treatment. METHODS: This prospective observational cohort study measured the GP and standard laboratory markers at three sample points: pre-treatment and at 20 and 60 days following 15âmg BD and 20âmg OD rivaroxaban respectively. RESULTS: Forty DVT patients (mean age 64 years [SD±14.8]; 23 males, 17 female) were recruited. The results show that DVT vs non-DVT patients did not have a significantly different GP profile (df: 1.72±0.06âvs 1.70±0.06 and TGP: 267±68âsec vs 262±73âsec) with both within the defined healthy index. In addition, rivaroxaban therapy increased TGP to 392âs (±135âs) after 20 days, and subsequently increased to 395âs (±194âs) at 60 days but did not significantly increase df (from 1.69±0.05 to 1.71±0.06). CONCLUSIONS: The results indicate in this cohort of DVT patients there was no underlying hypercoagulable effect as determined by gel point analysis. Furthermore, the anticoagulant effect of rivaroxaban prolonged clotting, suggesting a protective effect against clot formation, without significantly reducing clot microstructural properties.
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Rivaroxabán , Trombosis de la Vena , Anticoagulantes/farmacología , Anticoagulantes/uso terapéutico , Coagulación Sanguínea , Pruebas de Coagulación Sanguínea/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Rivaroxabán/farmacología , Rivaroxabán/uso terapéutico , Trombosis de la Vena/tratamiento farmacológicoRESUMEN
BACKGROUND: There are acute settings where assessing the anticoagulant effect of direct oral anticoagulants (DOACs) can be useful. Due to variability among routine coagulation tests, there is an unmet need for an assay that detects DOAC effects within minutes in the laboratory or at the point of care. METHODS: We developed a novel dielectric microsensor, termed ClotChip, and previously showed that the time to reach peak permittivity (T peak) is a sensitive parameter of coagulation function. We conducted a prospective, single-center, pilot study to determine its clinical utility at detecting DOAC anticoagulant effects in whole blood. RESULTS: We accrued 154 individuals: 50 healthy volunteers, 49 rivaroxaban patients, 47 apixaban, and 8 dabigatran patients. Blood samples underwent ClotChip measurements and plasma coagulation tests. Control mean T peak was 428 seconds (95% confidence interval [CI]: 401-455 seconds). For rivaroxaban, mean T peak was 592 seconds (95% CI: 550-634 seconds). A receiver operating characteristic curve showed that the area under the curve (AUC) predicting rivaroxaban using T peak was 0.83 (95% CI: 0.75-0.91, p < 0.01). For apixaban, mean T peak was 594 seconds (95% CI: 548-639 seconds); AUC was 0.82 (95% CI: 0.73-0.91, p < 0.01). For dabigatran, mean T peak was 894 seconds (95% CI: 701-1,086 seconds); AUC was 1 (p < 0.01). Specificity for all DOACs was 88%; sensitivity ranged from 72 to 100%. CONCLUSION: This diagnostic study using samples from "real-world" DOAC patients supports that ClotChip exhibits high sensitivity at detecting DOAC anticoagulant effects in a disposable portable platform, using a miniscule amount of whole blood (<10 µL).
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Pruebas de Coagulación Sanguínea/instrumentación , Monitoreo de Drogas/instrumentación , Inhibidores del Factor Xa/uso terapéutico , Anciano , Anciano de 80 o más Años , Coagulación Sanguínea/efectos de los fármacos , Pruebas de Coagulación Sanguínea/métodos , Dabigatrán/farmacología , Dabigatrán/uso terapéutico , Monitoreo de Drogas/métodos , Diseño de Equipo , Inhibidores del Factor Xa/farmacología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pirazoles/farmacología , Pirazoles/uso terapéutico , Piridonas/farmacología , Piridonas/uso terapéutico , Rivaroxabán/farmacología , Rivaroxabán/uso terapéuticoRESUMEN
PURPOSE: There are many anticoagulant test indexes available for direct oral anticoagulants (DOACs), but how to select the appropriate index and the index cutoff values are still controversial. This is the first study, to our knowledge, to assess the association of different coagulation indicators with clinical outcomes among DOACs using a meta-analysis of observational studies. METHODS: A medical literature search was conducted using PubMed, Web of Science, EMBASE, ClinicalTrials.gov, and the Cochrane Library from inception to February 2020. Studies that reported relationships between coagulation indexes and clinical outcomes or the diagnostic value of coagulation assays were included in the analysis. FINDINGS: A total of 17 articles (7 meta-analyses and 10 systematic reviews) from 8904 citations were included in the analysis. In the analysis of bleeding events with coagulation indexes for DOACs, for peak prothrombin time level (cutoff value of 19-25 s), the pooled results found a sensitivity of 0.61 (95% CI, 0.44-0.75) and a specificity of 0.71 (95% CI, 0.49-0.86). For rivaroxaban, the trough anti-factor Xa concentration (AXA-C) (cutoff value of 400-500 ng/mL) had a sensitivity of 0.53 (95% CI, 0.16-0.87) and a specificity of 0.87 (95% CI, 0.71-0.94), with a diagnostic odds ratio of 7 (95% CI, 2-32). For apixaban, trough AXA-C had a sensitivity of 0.85 (95% CI, 0.60-0.96) and a specificity of 0.83 (95% CI, 0.52-0.95). The AUC of the AXA-C peak was higher than that of the trough AXA-C for apixaban, with a higher sensitivity and specificity. Compared with trough concentration of anti-factor IIa for dabigatran, the peak concentration had a higher specificity (98%) at the cutoff value of 484 ng/mL. In the analysis of thromboembolic events with coagulation indexes for DOACs, peak and trough prothrombin time values were not typically correlated with subsequent symptomatic venous thromboembolism, without a sensitivity or specificity higher than 90%. Trough AXA-C had a sensitivity of 100% and but a low specificity (<50%) for rivaroxaban-apixaban. Trough AXA-C had a sensitivity of 100% and a specificity of 32% with a cutoff value of 108 ng/mL for dabigatran. IMPLICATION: Peak prothrombin time (19-25 s) and AXA-C had a better predictive value on bleeding outcomes for rivaroxaban and apixaban, whereas peak concentration of anti-factor IIa activity can be an indicator for dabigatran. Coagulation indexes might not be a good indicator of thromboembolic events of DOACs. Because the limited studies focused on association of coagulation indicators and clinical outcomes, more studies are needed to verify this in the future.
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Coagulación Sanguínea/efectos de los fármacos , Inhibidores del Factor Xa/uso terapéutico , Administración Oral , Pruebas de Coagulación Sanguínea/efectos adversos , Pruebas de Coagulación Sanguínea/métodos , Dabigatrán/uso terapéutico , Hemorragia/inducido químicamente , Humanos , Tiempo de Protrombina , Pirazoles/administración & dosificación , Piridonas/administración & dosificación , Rivaroxabán/uso terapéutico , Tromboembolia Venosa/tratamiento farmacológicoRESUMEN
Functional tests for lupus anticoagulants (LA) as part of a thrombophilia workup are commonly performed in patients under anticoagulant therapy that may interfere with assay results. There is no consensus on how these tests should be assessed in patients on direct oral anticoagulants (DOACs). In this retrospective cohort study, we analysed data from patients with a history of thrombosis in whom dilute Russell viper venom time (dRVVT), LA-sensitive aPTT, and solid phase assays for antiphospholipid antibodies (aPL) were performed (n = 3,147, thereof 588 on rivaroxaban, 144 on apixaban, 1,179 on other anticoagulant drugs). The dRVVT ratio was correlated with rivaroxaban (r = 0.30, P < 10-4) but not with apixaban plasma levels. The LA-sensitive aPTT/aPTT ratio showed no correlation with DOAC levels. Correspondingly, the rate of patients with abnormal dRVVT test was significantly higher (P < 10-4) under rivaroxaban (88%) than in thrombosis patients without anticoagulant medication (6%), independent from their aPL plasma levels. No isolated positive results of functional LA testing in patients on anticoagulants could be confirmed in repeated testing after discontinuation of the medication (n = 40). These data indicate that rivaroxaban should be discontinued before functional LA testing is performed. However, viable interpretation of these tests appears to be less affected in patients on apixaban.
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Anticoagulantes/uso terapéutico , Inhibidor de Coagulación del Lupus/uso terapéutico , Trombosis/tratamiento farmacológico , Administración Oral , Adulto , Anticuerpos Antifosfolípidos/uso terapéutico , Síndrome Antifosfolípido/tratamiento farmacológico , Coagulación Sanguínea/efectos de los fármacos , Pruebas de Coagulación Sanguínea/métodos , Dabigatrán/uso terapéutico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Tiempo de Tromboplastina Parcial/métodos , Tiempo de Protrombina/métodos , Pirazoles/uso terapéutico , Piridonas/uso terapéutico , Estudios Retrospectivos , Rivaroxabán/uso terapéutico , Trombofilia/tratamiento farmacológicoRESUMEN
BACKGROUND Laminaria japonica polysaccharide (LJP), a fucose enriched sulfated polysaccharide has been demonstrated to have excellent anticoagulant and antithrombotic activities. However, the antithrombotic effect of low molecular weight polysaccharide from enzymatically modified of LJP (LMWEP) remains unknown. MATERIAL AND METHODS LMWEP was prepared by fucoidanase enzymatic hydrolysis, and the antithrombotic and anticoagulant activities, and the underlying mechanism were investigated thoroughly. Rats were randomly divided into 6 groups (8 rats in each group): the blank control group, the blank control group treated with LMWEP (20 mg/kg), the model group, the model group treated with heparin (2 mg/kg), the model group treated with LJP (20 mg/kg), and the model group treated with LMWEP (20 mg/kg). After 7 days of intravenous administration, blood was collected for biochemical parameters examinations. RESULTS LMWEP increased the activated partial thromboplastin time (APTT), thrombin time (TT), prothrombin time (PT), 6-keto prostaglandin F1alpha (6-Keto-PGF1alpha), and endothelial nitric oxide synthase (eNOS). In addition, LMWEP decreased fibrinogen (FIB), endothelin-1 (ET-1), thromboxane B2 (TXB2), erythrocyte sedimentation rate (ESR), and hematocrit (HCT). CONCLUSIONS LMWEP, an enzymatically modified fragment with a molecular weight of 25.8 kDa, is a potential antithrombotic candidate for treatment of thrombosis related diseases.
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Fibrinolíticos/farmacología , Laminaria/química , Medicina Tradicional China/métodos , Animales , Anticoagulantes/uso terapéutico , Coagulación Sanguínea/efectos de los fármacos , Pruebas de Coagulación Sanguínea/métodos , Glicósido Hidrolasas/farmacología , Laminaria/efectos de los fármacos , Laminaria/metabolismo , Masculino , Óxido Nítrico Sintasa de Tipo III/sangre , Tiempo de Tromboplastina Parcial/métodos , Polisacáridos/farmacología , Tiempo de Protrombina/métodos , Ratas , Ratas Sprague-Dawley , Trombosis/sangreRESUMEN
INTRODUCTION: Investigation of factors (F) VIII and IX is common, with testing important for diagnosis or exclusion of haemophilia A or B, associated acquired conditions and factor inhibitors. Rivaroxaban, a common direct anti-Xa agent, causes significant interference in clotting assays, including substantial false reduction of factor levels. AIM: To assess whether rivaroxaban-induced interference of FVIII and FIX testing could be neutralized. MATERIALS AND METHODS: An international, cross-laboratory exercise for FVIII (n = 84) and FIX (n = 74), using four samples: (A) pool of normal plasma; (B) pool spiked with rivaroxaban (200 ng/mL); (C) rivaroxaban sample subsequently treated with 'DOAC Stop' and; (D) rivaroxaban sample treated with andexanet alfa (200 µg/mL). Testing performed blind to sample type. RESULTS: All laboratories reported normal FIX and 94% reported normal FVIII in the pool sample. Instead, 55% and 95%, respectively, reported abnormal FIX and FVIII levels for the rivaroxaban sample. DOAC Stop treatment evidenced a correction in most laboratories (100% reported normal FIX and 86% normal FVIII). Andexanet alfa provided intermediate results, with many laboratories still reporting abnormal results (59% for FVIII, 18% for FIX). We also identified reagent-specific issues. CONCLUSIONS: As expected, rivaroxaban caused false low values of FVIII and FIX. This might lead to increased testing to identify the cause of low factor levels and potentially lead to false identification of (mild) haemophilia A or B if unrecognized by clinicians/laboratories. DOAC Stop effectively neutralized the rivaroxaban effect, but andexanet alfa less so, with reagent-related effects evident, and thus, false low values sometimes persisted.
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Pruebas de Coagulación Sanguínea/métodos , Factor IX/uso terapéutico , Factor VIII/uso terapéutico , Hemostáticos/uso terapéutico , Rivaroxabán/uso terapéutico , Factor IX/farmacología , Factor VIII/farmacología , Hemostáticos/farmacología , Humanos , Rivaroxabán/farmacologíaRESUMEN
The exploration of thrombotic mechanisms relies on the application of blood collection methods from laboratory mice with a minimal pre-activation of platelets and the clotting system. So far, very little is known on how the blood collection method and the anticoagulant used influence pre-activation of mouse platelets and coagulation. To determine the most suitable blood collection method, we systematically compared blood collection by heart puncture, Vena cava puncture, and puncture of the retro-orbital vein plexus and the use of citrate, heparin, and EDTA as frequently used anticoagulants with regard to platelet activation and whole blood clotting parameters. The activation of platelet-rich plasma diluted in Tyrode's buffer was analyzed by flow cytometry, analyzing the exposure of P-selectin and activated integrin αIIbß3. Clotting of whole blood was profiled by thrombelastometry. Puncture of the retro-orbital vein plexus by plastic capillaries is not superior in terms of blood volume and platelet pre-activation, whereas heart puncture and Vena cava puncture resulted in similarly high blood volumes. Cardiac puncture and Vena cava puncture did not result in pre-activated platelets with citrate as an anticoagulant, but the use of EDTA resulted in increased levels of integrin αIIbß3 activation. Puncture of the retro-orbital vein plexus by plastic capillaries resulted in increased platelet integrin αIIbß3 activation, which could be prevented by soaking with citrate or coating with heparin. Further, activation of coagulation in citrated whole blood by puncture of the retro-orbital vein plexus using a blunt plastic capillary was observed by thromboelastometry. The use of citrate is the optimal anticoagulant in mouse platelet assays. Blood collections from the heart or Vena cava represent reliable alternatives to retro-orbital puncture of the vein plexus to avoid pre-activation of platelets and coagulation.
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Anticoagulantes/uso terapéutico , Pruebas de Coagulación Sanguínea/métodos , Pruebas de Función Plaquetaria/métodos , Animales , Anticoagulantes/farmacología , Humanos , Ratones , Ratones Endogámicos C57BLRESUMEN
: Evaluate the in-vitro effect of Mentha crispa extract on blood coagulation, compare the conventional coagulometric tests with thrombin generation test (TGT), and study the qualitative micromolecular composition of M. crispa. Extract of M. crispa was incubated with plasma and used in the coagulometric tests: prothrombin and activated partial thromboplastin times, fibrinogen, and TGT. A phytochemical prospection was performed to evaluate the chemical composition of this extract. The extract was efficient in prolonging prothrombin time and activated partial thromboplastin time, and reducing fibrinogen levels and TGT parameters, indicating that the extract of M. crispa inhibited the intrinsic and extrinsic pathways of blood coagulation. The results obtained in TGT are in agreement with the results of conventional coagulometric tests and the in-vitro anticoagulant activity of M. crispa suggests that its use by patients using oral anticoagulants deserves caution.
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Anticoagulantes/uso terapéutico , Pruebas de Coagulación Sanguínea/métodos , Coagulación Sanguínea/efectos de los fármacos , Mentha/química , Anticoagulantes/farmacología , Voluntarios Sanos , HumanosRESUMEN
BACKGROUND: Posterior spinal fusion for adolescent idiopathic scoliosis is a complex surgery often associated with clinically significant blood loss leading to perioperative blood transfusion. Knowledge of risk factors for blood loss and transfusion stems mostly from retrospective studies. AIM: We sought to prospectively investigate putative prognostic factors for intraoperative blood loss and perioperative blood transfusion in adolescent idiopathic scoliosis patients undergoing posterior spine fusion, including clinical characteristics, surgical factors, and preoperative assessment of overall coagulative and fibrinolytic functions in plasma using the clot formation and lysis (CloFAL) assay. METHODS: Following Internal Review Board approval, adolescents 10 to <21 years old with idiopathic scoliosis undergoing posterior spine fusion were enrolled preoperatively in a single-institutional prospective cohort and biobanking study. Clinical data were collected on patient characteristics, surgical approach, perioperative management, intraoperative estimated blood loss, and blood transfusion through hospital discharge. Coagulative and fibrinolytic functions in plasma were measured on preoperative samples by CloFAL assay (Coagulation Index and modified Fibrinolytic Index). Univariate linear regression and multivariable linear regression were performed to identify predictors of weight-indexed intraoperative estimated blood loss EBL (EBL/kg). RESULTS: The final study population included 74 patients. Median age was 14.8 years (SD = 2.2). After adjustment for other putative prognostic factors via multivariable linear regression, coagulative function as determined preoperatively by CloFAL Coagulation Index was an independent predictor of intraoperative (EBL)/kg. Specifically, each 10% increase in CloFAL CI was associated with 3% decrease in the geometric mean of EBL/kg (OR 0.97, 95%CI 0.94-0.99, P = .01). CONCLUSION: In adolescents undergoing posterior spinal fusion for idiopathic scoliosis, increased coagulative function measured preoperatively using the CloFAL assay is independently associated with decreased intraoperative blood loss. Future studies should expand upon these investigations of plasma coagulative and fibrinolytic capacities in combination with clinical factors, to guide precise preventive strategies against blood loss and blood transfusion in this patient population.
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Pruebas de Coagulación Sanguínea/métodos , Pérdida de Sangre Quirúrgica/prevención & control , Escoliosis/sangre , Escoliosis/cirugía , Fusión Vertebral/métodos , Adolescente , Bancos de Muestras Biológicas , Coagulación Sanguínea/fisiología , Transfusión de Sangre Autóloga/métodos , Femenino , Humanos , Masculino , Cuidados Preoperatorios/métodos , Pronóstico , Estudios Prospectivos , Estudios Retrospectivos , Adulto JovenRESUMEN
BACKGROUND: Apixaban and rivaroxaban are approved for the prevention and treatment of deep vein thrombosis (DVT), pulmonary embolism (PE), and embolic stroke in atrial fibrillation (AF) patients. The aim of this study was to find appropriate methods of monitoring the anticoagulant effects of are direct oral anticoagulants (DOACs) and establish on-therapy ranges using conventional tests. METHODS: A total of 184 samples were collected from 91 patients receiving DOACs. Concentrations of apixaban and rivaroxaban in plasma were accessed by an anti-factor Xa chromogenic assay. PT, APTT, antithrombin, D-dimer, dRVVT screen/confirm, FDP, and fibrinogen levels were measured. On-therapy ranges were calculated by substituting previously reported trough plasma concentrations of DOACs. RESULTS: Anti-factor Xa chromogenic assay-based DOACs levels were 26.0-279.5 (115.9 ± 56.5) ng/mL for apixaban at 2.5 mg BID, 19.9-565.1 (205.3 ± 162.4) ng/mL for apixaban at 5 mg BID, 2.3-395.3 (205.3 ± 162.4) ng/mL for rivaroxaban at 15 mg OD, 3.6-494.8 (119.6 ± 95.1) ng/mL for rivaroxaban at 20 mg OD, and 9.6-431.4 (140.8 ± 113.6) ng/mL for rivaroxaban at 15 mg BID. PT (%), antithrombin, and dRVVT confirm tests showed good correlation with plasma apixaban levels. Plasma rivaroxaban concentrations were correlated well with PT (sec), PT (%),and dRVVT confirm results. On-therapy ranges established for dRVVT confirm test by linear regression were as follows: 1.32-1.52 for apixaban 2.5 mg BID, 1.12-1.75 for apixaban 5 mg BID, 1.11-1.78 for rivaroxaban 15 mg OD, 1.09-1.64 for rivaroxaban 20 mg OD, and 1.22-1.81 for rivaroxaban 20 mg BID. CONCLUSIONS: Apixaban concentrations were well correlated with PT (%), antithrombin, and dRVVT confirm test. Rivaroxaban concentrations showed good correlation with PT (sec), PT (%), and dRVVT confirm test.
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Pruebas de Coagulación Sanguínea/métodos , Inhibidores del Factor Xa/sangre , Pirazoles/sangre , Piridonas/sangre , Rivaroxabán/sangre , Administración Oral , Adulto , Anciano , Anciano de 80 o más Años , Técnicas de Laboratorio Clínico , Inhibidores del Factor Xa/uso terapéutico , Femenino , Productos de Degradación de Fibrina-Fibrinógeno/análisis , Fibrinógeno/análisis , Humanos , Masculino , Persona de Mediana Edad , Tiempo de Protrombina , Pirazoles/uso terapéutico , Piridonas/uso terapéutico , Rivaroxabán/uso terapéutico , Venenos de VíborasRESUMEN
Effective control of bleeding is critical to saving lives whether on the battle field or in civilian life. Microporous starch (MS) is a promising hemostat for its extensive sources, huge surface area and good biocompatibility. However, the hemostatic performance of MS is limited because of its complex preparation process and lack of effective component to activate coagulation factors. Herein, porous starch microspheres modified by calcium (Ca-PSM) with dense shell and honeycomb micro-porous core were prepared by electrostatic spray and supercritical CO2 for the first time. The topological morphology of Ca-PSM changed with the increase of Tween-80 content within 0.5%. Ca-PSM possessed excellent water absorbability due to high specific surface area, and what's more, it showed good hemostatic performance because of the synergistic effects of physical adsorption and chemical activation mechanisms. The results of thrombelastograph (TEG) showed that the initial clotting time (R) and coagulation time (Râ¯+â¯K) of Ca-PSM-1 were shortened by 47.1%, 53.3% than that of control group. The maximum blood clot strength (MA) of Ca-PSM-1 was also significantly raised. Furthermore, it was noteworthy that Ca-PSM could activate clotting cascade and induce erythrocyte adsorption. In summary, Ca-PSM as a hemostat will be a promising and alternative candidate for clinical application.
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Dióxido de Carbono/química , Hemostáticos/química , Almidón/química , Adyuvantes Farmacéuticos/química , Coagulación Sanguínea/efectos de los fármacos , Pruebas de Coagulación Sanguínea/métodos , Hemorragia/prevención & control , Hemostasis/efectos de los fármacos , Microesferas , Porosidad , Electricidad Estática , Agua/químicaRESUMEN
Twenty-eight warmblood mares were monitored during their late pregnancy in the Teaching Hospital of Ghent University. The reliability of two commercial assays (enzyme immunoassay and glutaraldehyde coagulation test) used for determining the IgG concentrations of their newborn foals was tested. Mammary secretions were examined at the time of foaling (T0), and then 4 (T1) and 8 (T2) hours after foaling by refractometry and electrophoresis. The foals' blood IgG levels were measured at T1 and T2 as a routine clinical diagnostic examination using two different commercial test kits (SNAP Foal Ig and Gamma-Check E) and T0, T1 and T2 samples were stored (at -18 °C) for immunoglobulin (Ig) determination by electrophoresis. Differences between the results of refractometry and electrophoresis occurred in 27.8% of the colostrum analyses. Some serum IgG could be detected immediately post partum (T0) in 75% of the foals, and 42.82% of the newborn foals acquired a serum concentration of more than 800 mg/dl IgG within 8 h of birth. Compared to the electrophoresis, the glutaraldehyde test scored better (85%) than the enzyme immunoassay (74%), although both are accurate and safe to use since they clearly distinguish between safe and unsafe IgG concentrations.
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Pruebas de Coagulación Sanguínea/veterinaria , Pruebas Diagnósticas de Rutina/veterinaria , Electroforesis/veterinaria , Ensayo de Inmunoadsorción Enzimática/veterinaria , Refractometría/veterinaria , Animales , Animales Recién Nacidos , Pruebas de Coagulación Sanguínea/métodos , Calostro/química , Pruebas Diagnósticas de Rutina/métodos , Electroforesis/métodos , Ensayo de Inmunoadsorción Enzimática/métodos , Glutaral/química , Caballos , Inmunoglobulina G/sangre , Refractometría/métodos , Reproducibilidad de los ResultadosRESUMEN
Little is known about the challenging treatment of pediatric patients with hemophilia B and inhibitors due to disease rarity. We describe three patients diagnosed in childhood and followed up to 9 years. All three had allergic reactions to Factor IX, but two were later safely treated for bleeding episodes with activated prothrombin complex concentrates (APCC = FEIBA). The third was given only recombinant activated Factor VIIa. Based on ex vivo thrombin generation analysis, a new alternative treatment of combined bypassing agents was administered for bleeding episodes and several minor surgical procedures with no treatment-associated adverse events or thrombosis.
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Factores de Coagulación Sanguínea/uso terapéutico , Factor VIIa/uso terapéutico , Hemofilia B/tratamiento farmacológico , Trombina/biosíntesis , Adolescente , Pruebas de Coagulación Sanguínea/métodos , Preescolar , Humanos , Masculino , Proteínas Recombinantes/uso terapéutico , Trombina/efectos de los fármacosRESUMEN
INTRODUCTION: Discrepancies in the measurement of modified factor VIII (FVIII) products have been recognized, highlighting the need for adjustments in clinical laboratory practices to ensure effective monitoring of patients treated with these products, particularly using the one-stage (activated partial thromboplastin time [aPTT]) assay. AIM: To assess the ability of clinical laboratories to measure the activity of BAY 94-9027, a PEGylated extended half-life FVIII product, using routine (predominantly one-stage) assays in clinical laboratories METHODS: Blinded samples of FVIII-deficient plasma spiked with defined levels of BAY 94-9027 and a recombinant FVIII product comparator were provided to 52 clinical laboratories that routinely conduct FVIII testing. Samples were provided at 3 concentrations (low, medium and high), and laboratories analysed the samples using routine in-house one-stage and, when available, chromogenic assays. Acceptable spiked recovery (accuracy) of the local laboratory methods to measure BAY 94-9027 was the primary endpoint of the study. RESULTS: Accurate FVIII measurements were obtained at all concentrations for both products using the chromogenic assay and most of the commonly used one-stage reagents, both ellagic acid and silica based. Two specific silica-based reagents, APTT-SP and PTT-A, underestimated BAY 94-9027 levels at all concentrations, consistent with previous findings. CONCLUSIONS: FVIII activity of BAY 94-9027 was accurately measured with most commonly used one-stage assays used in routine clinical practice. The chromogenic assay was also accurate. It is recommended that clinical laboratories identify and avoid specific inappropriate reagents, such as the APTT-SP and PTT-A, in their one-stage assays for FVIII monitoring.
Asunto(s)
Pruebas de Coagulación Sanguínea/métodos , Factor VIII/uso terapéutico , Polietilenglicoles/uso terapéutico , Factor VIII/farmacología , Humanos , Laboratorios , Polietilenglicoles/farmacologíaRESUMEN
BACKGROUND: The use of kaolin-coated dressings has become common and have efficacy in normal patients, but their increased use will inevitably include use on bleeding patients taking anticoagulants. We hypothesize that kaolin coating material (KCM) will improve clotting regardless of anticoagulation medication. METHODS: A prospective study was performed on blood from patients who were on a vitamin K antagonist (VKA), unfractionated heparin (UH), an antiplatelet (AP) agent, a Xa inhibitor (Xa), or a direct thrombin inhibitor (DTI). None were on more than one type of anticoagulation medication. Viscoelastic testing was performed with and without KCM. All p values were adjusted for multiple comparisons. RESULTS: The addition of KCM significantly decreased the time for initial clot formation (CT) in all groups. The mean CT for controls was decreased from 692 to 190.8 s (p < 0.0001). KCM decreased the initial clot formation time by about 1.5 times in those on DTI (p = 0.043) and 2.5 times in those taking AP medication (p < 0.001). The most profound effect was seen in those on UH (no KCM 1,602 s vs. KCM 440 s; p < 0.001), VKA (no KCM 1,152 s vs. 232 s; p < 0.01), and Xa (no KCM 1,342 s vs. 287 s; p < 0.001). Analysis of other clot formation parameters revealed that KCM significantly improved the clot formation kinetics (CFT) only in patients taking Xa (p = 0.03). KCM improved maximum clot strength in patients on Xa inhibitors (p = 0.05). Patients on UH had a larger effect size with an increase in clot strength from 24.35 mm to 43.35 mm whereas those on Xa had an increase of 38.7 mm to 49.85 mm. CONCLUSION: In this in vitro analysis, the addition of KCM to the blood of patients taking any of these anticoagulation medications significantly improved the time to initial clot formation, indicating that kaolin-based hemostatic dressings will be effective in initiating clot formation in patients on anticoagulants. LEVEL OF EVIDENCE: Therapeutic, level IV.
Asunto(s)
Coagulación Sanguínea/efectos de los fármacos , Hemostáticos/uso terapéutico , Caolín/farmacología , Vitamina K/antagonistas & inhibidores , Adulto , Anticoagulantes/administración & dosificación , Anticoagulantes/uso terapéutico , Antitrombinas/sangre , Arginina/análogos & derivados , Vendajes/tendencias , Pruebas de Coagulación Sanguínea/métodos , Dabigatrán/administración & dosificación , Dabigatrán/uso terapéutico , Inhibidores del Factor Xa/sangre , Heparina/sangre , Humanos , Caolín/efectos adversos , Ácidos Pipecólicos/administración & dosificación , Ácidos Pipecólicos/uso terapéutico , Inhibidores de Agregación Plaquetaria/sangre , Estudios Prospectivos , Rivaroxabán/administración & dosificación , Rivaroxabán/uso terapéutico , Sulfonamidas , Sustancias Viscoelásticas/química , Vitamina K/sangreRESUMEN
The polyphenolic-polysaccharide conjugates were isolated from flowers and fruits of medicinal plant Crataegus monogyna Jacq. (Lindm.) by the alkaline extraction, followed by neutralization, partitioning with organic solvents and dialysis against water. The isolates from flowers as well as from fruits were homogenous macromolecular compounds, with a molecular weight over 760â¯×â¯103â¯g/mol and 970â¯×â¯103â¯g/mol, respectively, what was assessed in HPGPC analysis. Both products were characterized spectrophotometrically, and by GLC-MS, FT-IR and NMR techniques. They were composed of polyphenolic matrices containing some flavonoid units and of polysaccharide structures rich in galacturonic acid with low esterification degree. Moreover, galactose, glucose, rhamnose and arabinose residues, with different proportions of monosaccharides were present, depending on the type of the starting plant material. Both plant preparations were able to prolong the plasma coagulation process in vitro tests, even at the concentration of 31.25⯵g/mL. However, they differed in the mechanisms of the activity, where only the product isolated from flowers of C. monogyna was highly selective in its action. It was mainly the non-direct inhibitor of factor Xa, mediated by antithrombin, where such mechanism of activity is typical for highly sulfated glycosaminoglycans.
Asunto(s)
Anticoagulantes , Coagulación Sanguínea/efectos de los fármacos , Crataegus/química , Flores/química , Extractos Vegetales/química , Polifenoles , Polisacáridos , Anticoagulantes/química , Anticoagulantes/farmacología , Pruebas de Coagulación Sanguínea/métodos , Humanos , Polifenoles/química , Polifenoles/farmacología , Polisacáridos/química , Polisacáridos/farmacologíaRESUMEN
For many years, the importance of fibrinolysis has been recognized, first for its intravascular antithrombotic action, and more recently for its many extravascular activities, associated with matrix degradation and tissue remodeling. In the blood circulation system, fibrinolysis prevents thrombosis, and is associated with various biological and clinical situations: risk factors for cardio-vascular diseases in high risk clinical situations (type II diabetes, hypertension, triglycerides, high BMI, elevated glucose, etc.), probably resulting from a significant reduction of the fibrinolysis potential, and elevation of PAI-1. Noteworthy, t-PA is mainly present as an inactive complex with PAI-1, and its concentration in plasma tends to follow that of PAI-1, but in a lesser extent. Hypofibrinolysis can favor the occurrence of thrombotic events, and possibly other biological dysfunctions. Fibrinolysis activity is however difficult to evaluate as it has a delayed activity after clot formation, is initiated and regulated after fibrin generation, and conversely to clotting, its action is delayed (long lag phase) and slow, before being dramatically amplified leading to rapid clot dissolution. We have designed a new assay for evaluating the global fibrinolytic capacity (GFC) in the body. Reagents are used in association with a specific instrument, which can be connected to any computer, and dedicated software is used for analyzing clot lysis kinetics. The assay is performed in a micro-cuvette, introduced into one of the instrument wells at 37⯰C, and light transmittance is continuously measured. Assayed plasma is first supplemented with a limited and constant amount of t-PA with silica and is then clotted with thrombin and calcium. Clot dissolution (measurement of turbidity change) is recorded over time using the dedicated instrument (Lysis Timer), and clot lysis kinetics are analyzed with the associated software: primary and secondary derivatives of the light transmission curve give information on kinetics and completion of clot dissolution. Total assay time is about 1â¯h (but in the presence of hypofibrinolysis it can be prolonged). The concentration of t-PA used for the assay has been adjusted (100â¯ng/ml) to obtain an optimal sensitivity to hypofibrinolysis within a short time interval, and clot dissolution occurs within about 45â¯min for normal individuals, with a broad range from 30â¯min to 60â¯min, with some samples presenting a clot dissolution time >60â¯min (hypofibrinolysis). This new assay is performed with the tested plasma intrinsic factors, especially its own fibrinogen, and only exogeneous t-PA is added. GFC is highly sensitive to PAI-1 activity, but other factors regulating fibrinolysis contribute to the clot dissolution kinetics. Freshly prepared or frozen and thawed citrated plasma can be used. The usefulness of this assay for clinical applications is under investigation. Although fibrinolysis is mainly initiated in the body upon stimulation or blood clotting, and rapidly diluted and inhibited in the circulation, evaluation of its "residual" activity in plasma is expected to reflect its global body potential.
Asunto(s)
Fibrinólisis , Hemostasis , Trombosis/sangre , Pruebas de Coagulación Sanguínea/métodos , Humanos , Factores de RiesgoRESUMEN
CONTEXT: Selaginella tamariscina (P. Beauv.) Spring (Selaginellaceae) (ST) has been widely used in China as a medicine for improving blood circulation. However, its processed product, S. tamariscina carbonisatus (STC), possesses opposite haemostatic activity. OBJECTIVE: To comprehensively evaluate the activity of ST and STC on physiological coagulation system of rats, and seek potential active substances accounting for the activity transformation of ST during processing. MATERIALS AND METHODS: The 75% methanol extracts of the whole grass (fine powder) of ST and STC were prepared, respectively. Male Sprague-Dawley rats were randomly divided into five groups: control group, model group, model + ST group, model + STC group and positive control group (model + Yunnanbaiyao). The duration of intragastric administration was 72 h at 12 h intervals. Haemorheology parameters were measured using an LB-2 A cone-plate viscometer and the existed classic methods, respectively. SC40 semi-automatic coagulation analyzer was employed to determine coagulation indices. Meanwhile, HPLC and LC-MS were applied for chemical analyses of ST and STC extracts. RESULTS: STC shortened tail-bleeding time, increased whole blood viscosity (WBV) and plasma viscosity (PV), decreased erythrocyte sedimentation rate blood (ESR), reduced activated partial thromboplastin time (APTT) and increased the fibrinogen (FIB) content in the plasma of bleeding model rats. Although ST could shorten APTT and TT, the FIB content was significantly decreased by ST. Dihydrocaffeic acid with increased content in STC vs. ST showed haemostatic activity for promoting the platelet aggregation induced by collagen and trap-6, and reducing APTT and PT significantly with a concentration of 171.7 µM in vitro. Amentoflavone with reduced content in STC vs. ST inhibited ADP and AA-induced platelet aggregation significantly with a concentration of 40.7 µM. DISCUSSION AND CONCLUSIONS: As the processed product of ST, STC showed strong haemostatic activity on bleeding rat through regulating the parameters involved in haemorheology and plasma coagulation system. Two active compounds, dihydrocaffeic acid and amentoflavone, might be partially responsible for the haemostatic and anticoagulant activity of STC and ST, respectively.
Asunto(s)
Coagulación Sanguínea/efectos de los fármacos , Hemostáticos/farmacología , Calor/efectos adversos , Extractos Vegetales/farmacología , Selaginellaceae , Animales , Tiempo de Sangría/métodos , Coagulación Sanguínea/fisiología , Pruebas de Coagulación Sanguínea/métodos , Hemostáticos/aislamiento & purificación , Masculino , Extractos Vegetales/aislamiento & purificación , Distribución Aleatoria , Ratas , Ratas Sprague-DawleyRESUMEN
BACKGROUND: Unanticipated drug-laboratory interactions may occur between direct oral anticoagulants (DOACs) and anti-factor Xa (AXA) levels used to monitor parenteral heparin infusions. Characterization of the extent and duration of DOAC effect on AXA levels may reduce complications with transition to heparin infusions. OBJECTIVE: To evaluate the impact of oral factor Xa inhibitors on AXA levels with and without concurrent heparin. METHODS: This retrospective descriptive study was approved by institutional review board waiver and included patients with AXA levels drawn on a heparin calibrated assay who had received a factor Xa inhibitor. Participants were divided on the basis of whether AXA levels were drawn with concurrent parenteral heparin. If transitioned to heparin, number of AXA draws required until AXA level was within therapeutic range was recorded. RESULTS: A total of 50 patients (60% rivaroxaban, 40% apixaban) met inclusion criteria. When AXA levels were drawn within 12 hours of apixaban without concurrent heparin (n = 7), 71% were greater than 1 IU/mL, and 29% were below suggested trough levels (0.7-1.1 IU/mL). For AXA levels drawn within 24 hours of rivaroxaban without concurrent heparin (n = 11), 55% were greater than 1 IU/mL, 9% were within suggested trough (0.6-1 IU/mL), and 36% were below 0.6 IU/mL. In patients (n = 28) who were initiated on heparin infusion prior to AXA monitoring, administration of the DOAC within the prior 72 hours resulted in supratherapeutic initial AXA levels 69% of the time. CONCLUSION: DOACs may cause elevations in heparin-calibrated AXA assays; this creates problematic challenges in using the AXA level to optimize heparin management.