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Viral hemorrhagic fevers (HF) are a group of acute febrile diseases with high mortality rates. Although hemostatic dysfunction appears to be a major determinant of the severity of the disease, it is still unclear what pathogenic mechanisms lead to it. In clinical studies it is found that arenaviruses, such as Lassa, Machupo, and Guanarito viruses cause HF that vary in symptoms and biological alterations. In this study we aimed to characterize the hemostatic dysfunction induced by arenaviral HF to determine its implication in the severity of the disease and to elucidate the origin of this syndrome. We found that lethal infection with Machupo, Guanarito, and Lassa viruses is associated with cutaneomucosal, cerebral, digestive, and pulmonary hemorrhages. The affected animals developed a severe alteration of the coagulation system, which was concomitant with acute hepatitis, minor deficit of hepatic factor synthesis, presence of a plasmatic inhibitor of coagulation, and dysfunction of the fibrinolytic system. Despite signs of increased vascular permeability, endothelial cell infection was not a determinant factor of the hemorrhagic syndrome. There were also alterations of the primary hemostasis during lethal infection, with moderate to severe thrombocytopenia and platelet dysfunction. Finally, we show that lethal infection is accompanied by a reduced hematopoietic potential of the bone marrow. This study provides an unprecedented characterization of the hemostasis defects induced by several highly pathogenic arenaviruses.
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Arenaviridae , Arenavirus , Febres Hemorrágicas Virais , Hemostáticos , Animais , Febres Hemorrágicas Virais/patologia , Hemorragia/etiologia , Hemostasia , MacacaRESUMO
BACKGROUND: Efmoroctocog alfa (rFVIIIFc) is an extended half-life FVIII used notably in surgery for patients with haemophilia A. More information is needed of its usage in real-life. METHODS: Adult patients with HA followed at the Lyon Comprehensive Hemophilia Care Center who underwent a surgery with rFVIIIFc were included in this retrospective analysis. The pharmacokinetics of rFVIIIFc was assessed by plasma factor VIII clotting activity (FVIII:C) using both one-stage (OSA) and chromogenic substrate (CSA) assays. RESULTS: A total of 39 major and 31 minor surgeries were performed in 49 patients treated with rFVIIIFc. The median dose of rFVIIIFc infused before major and minor surgeries respectively was 67.5 ((interquartile range [IQR] 52.6-76.9) and 48.0 (38.5-51.8) IU/kg. For major surgeries, during the first postoperative week, the median residual FVIII:C was 78 (64.5-101.5) IU/dL with OSA and 99 (71-118) IU/dL with CSA (p < .0001). After surgery, rFVIIIFc doses were adjusted according to CSA results. This led to a significant decrease of rFVIIIFc consumption compared to what would have been proposed according to the OSA assay, without unusual bleeding or appearance of inhibitor. Considering the high price of the molecule, this was also associated with a significant cost reduction. CONCLUSION: Dose adjustment of rFVIIIFc according to FVIII: C measured by CSA is effective, safe and well tolerated in patients with haemophilia A undergoing invasive surgery.
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Fator VIII , Hemofilia A , Fragmentos Fc das Imunoglobulinas , Adulto , Humanos , Fator VIII/uso terapêutico , Hemofilia A/tratamento farmacológico , Estudos Retrospectivos , Proteínas Recombinantes de Fusão/uso terapêutico , Proteínas Recombinantes/uso terapêutico , Meia-VidaRESUMO
BACKGROUND: In patients with FXI deficiency, the risk of surgery-related bleeding is poorly correlated with plasma FXI activity (FXI:C); the latter can therefore not be used as a reliable predictor of bleeding in surgeries. OBJECTIVES: The aim of this retrospective study was to determine whether thrombin generation assay (TGA) could be used to evaluate the risk of surgery-related bleeding in FXI-deficient patients. TGA parameters were compared to FXI:C values, haemostatic treatments and surgical outcomes. PATIENTS: All patients followed at the haemophilia treatment care centre (Lyon, France) with a FXI:C < 50IU/dL, and for whom a baseline TGA was performed between January 2014 and December 2019, were included. RESULTS: Among the 175 surgeries reported herein in 49 patients, FXI concentrates were used for 11 (6%) surgeries and fresh frozen plasma was used for five (3%) surgeries; these surgeries were performed in patients with two or three impaired TGA parameters. No haemostatic treatment was prescribed for 119 (68%) surgeries. A surgery-related bleeding occurred in 12 patients during 21 (12%) surgeries. Thrombin generation was significantly reduced or delayed in patients who reported surgery related-bleeding. Among the 34 (68%) surgeries performed without haemostatic treatment in patients with three impaired TGA parameters, a surgery-related bleeding was reported in 44% of cases (15 surgeries out of 34). CONCLUSION: The present study confirmed that TGA is an interesting laboratory test in FXI deficiency, for determining the bleeding risk and guiding the haemostatic management of surgeries, while taking into account the surgical bleeding risk and the history of bleeding.
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Deficiência do Fator XI , Trombina , Perda Sanguínea Cirúrgica , Fator XI , Deficiência do Fator XI/complicações , Deficiência do Fator XI/cirurgia , Humanos , Estudos Retrospectivos , Trombina/uso terapêuticoRESUMO
The aim of this study was to (1) analyze blood viscosity, red blood cell (RBC) deformability, and aggregation in hospitalized patients with Coronavirus disease 19 (COVID-19); (2) test the associations between impaired blood rheology and blood coagulation; and (3) test the associations between impaired blood rheology and several indicators of clinical severity. A total of 172 patients with COVID-19, hospitalized in COVID-unit of the Internal Medicine Department (Lyon, France) participated in this study between January and May 2021. Clinical parameters were collected for each patient. Routine hematological/biochemical parameters, blood viscosity, RBC deformability and aggregation, and RBC senescence markers were measured on the first day of hospitalization. A control group of 38 healthy individuals was constituted to compare the blood rheological and RBC profile. Rotational thromboelastography was performed in 76 patients to study clot formation dynamics. Our study demonstrated that patients with COVID-19 had increased blood viscosity despite lower hematocrit than healthy individuals, as well as increased RBC aggregation. In-vitro experiments demonstrated a strong contribution of plasma fibrinogen in this RBC hyper-aggregation. RBC aggregation correlated positively with clot firmness, negatively with clot formation time, and positively with the length of hospitalization. Patients with oxygen supplementation had higher RBC aggregation and blood viscosity than those without, and patients with pulmonary lesions had higher RBC aggregation and enhanced coagulation than those without. This study is the first to demonstrate blood hyper-viscosity and RBC hyper-aggregation in a large cohort of patients with COVID-19 and describe associations with enhanced coagulation and clinical outcomes.
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Viscosidade Sanguínea , COVID-19/sangue , Agregação Eritrocítica , Eritrócitos/patologia , Adulto , Idoso , Coagulação Sanguínea , COVID-19/diagnóstico , COVID-19/patologia , Deformação Eritrocítica , Humanos , Pessoa de Meia-Idade , SARS-CoV-2/isolamento & purificaçãoRESUMO
Emicizumab, a bispecific humanised monoclonal antibody restoring to some extent the function of activated FVIII deficient in haemophilia A, represents a major therapeutic advance in the management of haemophilia A patients. No dosage adjustment is required, which leads to a major change for patients used to regular biological monitoring which is particularly burdensome in the case of substitution therapy. In some circumstances, such as before an invasive procedure or in case of bleeding, biological monitoring will be necessary and emicizumab's interference with haemostasis tests, particularly those based on an activated partial thromboplastin times (aPTT), must be known to best interpret the tests and to select the most appropriate methods to guide therapy. The normalisation of aPTT in patients treated with emicizumab is not sufficient to consider haemostasis as normalised. In the event of administration of FVIII to a patient receiving emicizumab, the determination of FVIII should use a chromogenic method using non-human reagents. Coagulation global tests have been proposed to evaluate the biological response when using bypassing agents in patients treated with emicizumab, but the usefulness must be confirmed. The French group BIMHO presents proposals for biological monitoring of a patient treated with emicizumab according to clinical situations.
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Anticorpos Biespecíficos/uso terapêutico , Anticorpos Monoclonais Humanizados/uso terapêutico , Coagulação Sanguínea/efeitos dos fármacos , Hemofilia A/sangue , Hemofilia A/tratamento farmacológico , Anticorpos Biespecíficos/administração & dosagem , Anticorpos Biespecíficos/efeitos adversos , Anticorpos Monoclonais Humanizados/administração & dosagem , Anticorpos Monoclonais Humanizados/efeitos adversos , Testes de Coagulação Sanguínea/métodos , Hemostasia/efeitos dos fármacos , Humanos , Resultado do TratamentoRESUMO
Replacement therapy with plasma-derived or recombinant FVIII and FIX (pdFVIII/pdFIX or rFVIII/rFIX) concentrates is the standard of treatment in patients with haemophilia A and B, respectively. Measurement of factor VIII (FVIII:C) or factor IX (FIX:C) levels can be done by one-stage clotting assay (OSA) or chromogenic substrate assay (CSA). The French study group on the Biology of Hemorrhagic Diseases (a collaborative group of the GFHT and MHEMO network) presents a literature review and proposals for the monitoring of FVIII:C and FIX:C levels in treated haemophilia A and B patients, respectively. The use of CSA is recommended for the monitoring of patients treated with pdFVIII or rFVIII including extended half-life (EHL) rFVIII. Except for rFVIII-Fc, great caution is required when measuring FVIII:C levels by OSA in patients substituted by EHL-rFVIII. The OSA is recommended for the monitoring of patients treated with pdFIX or rFIX. Large discordances in the FIX:C levels measured for extended half-life rFIX (EHL-rFIX), depending on the method and reagents used, must lead to great attention when OSA is used for measuring FIX:C levels in patients substituted by EHL-rFIX. Data of most of recent studies, obtained with spiked plasmas, deserve to be confirmed in plasma samples of treated patients.
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Fator IX/farmacocinética , Fator VIII/farmacocinética , Hemofilia A/sangue , Hemofilia A/tratamento farmacológico , Hemofilia B/sangue , Hemofilia B/tratamento farmacológico , Coagulação Sanguínea , Testes de Coagulação Sanguínea/métodos , Tomada de Decisão Clínica , Gerenciamento Clínico , Monitoramento de Medicamentos , Fator IX/administração & dosagem , Fator VIII/administração & dosagem , Hemofilia A/diagnóstico , Hemofilia B/diagnóstico , Humanos , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/farmacocinética , Resultado do TratamentoRESUMO
INTRODUCTION: Recombinant FVIIa (rFVIIa) is widely used to manage bleeding risk during and after surgery in patients with haemophilia complicated by inhibitors. In the postoperative period, rFVIIa must be delivered frequently and regularly to maintain haemostasis, considering its short half-life. Preparation and manual administration of bolus doses of rFVIIa at regular intervals may place a strain on available nursing resources. A programmable mini-pump may offer an approach to facilitate regular administration of bolus doses of rFVIIa at specified intervals. AIM: To investigate if a mini-pump is a practical and effective way to deliver rFVIIa in the postoperative period. METHODS: It was first necessary to establish that rFVIIa remains stable and sterile in the mini-pump reservoir for an extended period. Four days after loading the mini-pump under sterile conditions no evidence of bacterial or fungal growth was observed and in vitro procoagulant activity of rFVIIa remained stable. The mini-pump was used to deliver rFVIIa as bolus doses to two patients with inhibitors who had undergone surgery. Nurses were asked to report their satisfaction with the use of the mini-pump using a specific questionnaire. RESULTS: Haemostasis was evaluated as excellent in both cases; nurses were satisfied with use of the mini-pump. CONCLUSION: This pilot study shows that intermittent delivery of rFVIIa at fixed intervals using an automated mini-pump offers accurate and reliable administration in the postoperative setting. This approach may reduce burden on nursing staff, potentially minimize the risk of human error and avoid delay in administration of rFVIIa.
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Sistemas de Liberação de Medicamentos/instrumentação , Fator VIIa/administração & dosagem , Adulto , Idoso , Automação , Fator VIIa/uso terapêutico , Humanos , Masculino , Enfermeiras e Enfermeiros/estatística & dados numéricos , Projetos Piloto , Período Pós-Operatório , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/uso terapêutico , Inquéritos e QuestionáriosRESUMO
BACKGROUND: Classically, the study of splicing impact of variation located near the splice site is performed by both in silico and mRNA analysis. However, RNA sample was rarely available. OBJECTIVE: To characterize a panel of putative haemophilia A splicing variations. MATERIALS AND METHODS: Twenty-six F8 variations identified from a cohort of 2075 haemophilia A families were studied using both bioinformatic tools and in vitro minigene assays in HeLa and Huh7 cells. RESULTS: An aberrant splicing was demonstrated for 21/26 tested sequence variations. A good correlation between in silico and in vitro analysis was obtained for variations affecting donor splice site (12/14) and for the synonymous variations located inside an exon (6/6). Conversely, no concordant results were observed for the six variations affecting acceptor splice sites. The variations resulted more frequently in exon skipping (n = 13) than in activation of nearby cryptic splice sites (n = 5), in use of a de novo splice site (n = 2) or in insertion of large intronic sequences (n = 1). This study allowed to reclassify 5 synonymous substitutions c.1167A>G (p.Gln389Gln), c.1569G>T (p.Leu523Leu), c.1752G>A (p.Gln584Gln), c.5586G>A (p.Leu1862Leu) and c.6066C>T (p.Gly2022Gly) as splicing variations. The pathological significance of five variations remained unclear (c.222G>A [p.Thr74Thr], c.237C>T [p.Asn79Asn], c.240C>T [p.Ile80Ile], c.2113+5_2113+8del and c.2113+5G>A). DISCUSSION: The minigene assay herein gave additional evidences for the clinical significance of 21/26 F8 putative splice site mutations. Such investigation should be performed for each F8 putative splice site variation for which no mRNA sample is available, notably to greatly improve the genetic counselling given to female carriers.
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Fator VIII/genética , Hemofilia A/genética , Splicing de RNA , Adolescente , Adulto , Criança , Pré-Escolar , Biologia Computacional/métodos , Éxons , Genes Reporter , Hemofilia A/patologia , Humanos , Lactente , Masculino , Mutação de Sentido Incorreto , Polimorfismo de Nucleotídeo Único , Sítios de Splice de RNA , Sistema de Registros , Índice de Gravidade de Doença , Adulto JovemRESUMO
Background: Despite systematic thromboprophylaxis, 30% of the COVID-19 patients in intensive care units develop thrombosis. This occurrence is associated with a hypofibrinolytic state measured by thromboelastometry when adding tissue plasminogen activator (tPA) to citrated whole blood for a further run for EXTEM (ROTEM). Objectives: Because hydroxyethyl starches (HESs) affect fibrin polymerization, we have assessed its potential effect on in vitro tPA-induced fibrinolysis. Methods: Fifteen successive COVID-19 patients from the local intensive care units were selected for tPA resistance occurrence. HES was added to whole blood samples with proportion similar to the pharmacologic recommendations. Samples were run for EXTEM on a ROTEM delta device after further addition of tPA. Paired controls were whole blood samples with the same volume of saline added. To assess the impact of HES on coagulation, thrombin generation was measured in 10 COVID-19 patients in the presence of either HES or saline; then, the clots obtained were used to generate electron microscope images. Results: Clot firmness at 5 minutes and the lysis index at 30 minutes were decreased in presence of HES compared with saline (Wilcoxon test, P < .01 for HES vs saline and HES vs untreated). However, no statistically significant difference was observed for all thrombin generation assay parameters studied (endogenous thrombin potential, peak thrombin, and time to peak). With HES, fibrin fibers of either COVID-19 patients or control subjects were thicker than those of saline-treated samples. Conclusion: These results highlight that HES increased apparent in vitro tPA-induced fibrinolysis in case of severe COVID-19 disease. Use of this plasma volume expander may translate as a potential help against COVID-19-induced thrombosis occurrence.
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INTRODUCTION: Point of care (POC) analyzers are an integral part of the patient care. Transfuse can be an emergency decision, not being a benign act, it is necessary to ensure that the hemoglobin value measured by the POC are comparable with the reference analyzer. The objective is to compare the analytical performance of three POCs: ABL800 Flex, Hemocue and iSTAT and a central laboratory analyzer: XN-10 and the impact on the transfusion decision. METHODS: An in vitro study was performed in 50 patients for whom a hemogram had been prescribed on the XN-10, the hemoglobin determination was performed in parallel on the three POCs. Then, retrospective study was performed to compare the hemoglobin values returned for matched samples in routine practice, 5505 for ABL800 Flex, 55 for Hemocue and 70 for iSTAT were analyzed. RESULTS: In vitro study shows systematic biases in the measurement of hemoglobin between the different analyzers, overestimation for the ABL800 Flex and the Hemocue, underestimation for the iSTAT. These biases are accentuated in current practice for iSTAT but decreased for ABL800 Flex. In the transfusion decision range from 70 to 100 g/L, there were 8.6% of clinically discordant results between the reference method and ABL, 34.8% for Hemocue and 21.4% for iSTAT. CONCLUSION: In addition to systematic biases, many additional factors may be involved for variation in hemoglobin measurement with POC. Thus, in the case of urgent transfusion decisions, sending a hemogram on a central laboratory analyzer seems to be essential, while being compatible with a life-threatening emergency.
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Testes Hematológicos , Testes Imediatos , Humanos , Estudos Retrospectivos , Gasometria/métodos , Sistemas Automatizados de Assistência Junto ao Leito , Hemoglobinas/análiseRESUMO
The Lyon Hospitals Board (HCL) hemostasis laboratory has shifted from a frequentist to a long-term Bayesian approach to IQC results management, using the Hemohub® software of the Werfen corporation, which hosts the requisite Bayesian tools. IQC plans based on supplier specifications proved effective in managing analytic risk in line with the ISO 15189 standard. Long-term Hemohub® control and monitoring has been validated by acceptable feedback from the EQA organization used by the hemostasis community.
Assuntos
Hemostasia , Laboratórios Hospitalares , Humanos , Teorema de Bayes , Controle de QualidadeRESUMO
Acute normoxic exercise impacts the rheological properties of red blood cells (RBC) and their senescence state; however, there is a lack of data on the effects of exercise performed in hypoxia on RBC properties. This crossover study compared the effects of acute hypoxia vs. normoxia on blood rheology, RBC senescence, and coagulation during exercise. Nine trained male cyclists completed both a session in normoxia (FiO2 = 21%) and hypoxia (FiO2 = 15.3% ≈ 2500 m). The two sessions were randomly performed, separated by one week, and consisted of an incremental and maximal exercise followed by a 20 min exercise at the first ventilatory threshold (VT1) on a home-trainer. Blood samples were taken before and after exercise to analyze hematological parameters, blood rheology (hematocrit, blood viscosity, RBC deformability and aggregation), RBC senescence markers (phosphatidylserine (PS) and CD47 exposure, intraerythrocyte reactive oxygen species (ROS), and calcium content), and blood clot viscoelastic properties. Hemoglobin oxygen saturation (SpO2) and blood lactate were also measured. In both conditions, exercise induced an increase in blood viscosity, hematocrit, intraerythrocyte calcium and ROS content, and blood lactate concentration. We also observed an increase in blood clot amplitude, and a significant drop in SpO2 during exercise in the two conditions. RBC aggregation and CD47 exposure were not modified. Exercise in hypoxia induced a slight decrease in RBC deformability which could be related to the slight increase in mean corpuscular hemoglobin concentration (MCHC). However, the values of RBC deformability and MCHC after the exercise performed in hypoxia remained in the normal range of values. In conclusion, acute hypoxia does not amplify the RBC and coagulation changes induced by an exercise bout.
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BACKGROUND: Severe postpartum hemorrhage (PPH), defined as a blood loss ≥1000 mL, is associated with maternal morbidity and mortality. OBJECTIVES: We aimed at characterizing coagulation properties of predelivery plasmas from pregnant women with thrombin generation assay and hemostatic biomarkers (plasminogen activator inhibitor-1, tissue factor [TF], and thrombomodulin). METHODS: A nested case-control study was conducted within the "Study of Biological Determinants of Bleeding Postpartum," a French prospective cohort study, in order to compare women with severe PPH (cases) and controls matched for age, body mass index, term, and mode of delivery. Plasma was collected at entry in the delivery room, and blood loss was measured objectively. The predelivery endogenous thrombin generation potential (ETP) was measured in plasma using calibrated automated thrombinography and low TF concentration. Hemostatic biomarkers were measured using ELISA kits. RESULTS: A total of 142 women (71 cases and 71 controls) were investigated. There was no difference in the median lag phase, thrombin peak, and time to peak between cases and controls. However, median predelivery ETP was lower in cases than in controls (2170 vs 2408 nM.min, P < .0001), independently of mode of delivery and PPH etiology. Median plasminogen activator inhibitor-1 and TF levels were higher in cases compared with controls (107.4 vs 68.1 ng/mL, P = .0003; 34.4 vs 27.4 pg/mL, P = .007), whereas thrombomodulin levels did not differ between the 2 groups. CONCLUSION: Among thrombin generation assay parameters, predelivery ETP levels may have a predictive value for severe PPH.
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Hemostáticos , Hemorragia Pós-Parto , Humanos , Feminino , Gravidez , Masculino , Trombina , Trombomodulina , Hemorragia Pós-Parto/diagnóstico , Testes de Coagulação Sanguínea , Estudos de Casos e Controles , Estudos Prospectivos , Tromboplastina , Período Pós-Parto , Biomarcadores , Inativadores de PlasminogênioRESUMO
BACKGROUND: Heparin diminishes thrombin generation (TG) because it decreases the survival time of thrombin in plasma. Under heparin therapy, the TG curve therefore does not reflect the true hemostatic status of the patient. AIM: We investigated how far the in vitro addition of a heparin antagonist can restore the underlying TG capacity. MATERIALS & METHODS: Five different heparin antagonists were tested: polybrene, protamine sulfate, heparinase type 1, heparinase HEP-TEM, and (Z-GGR)2 -rhodamine (P2Rho). RESULTS AND CONCLUSION: Polybrene, P2Rho, and heparinase HEP-TEM effectively neutralized heparin at prophylactic and therapeutical doses of both low molecular weight and unfractionated heparin. The advantages and limits of each molecule and the most favorable combinations of TG-trigger and antagonist are discussed.
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Trombina , Trombofilia , Anticoagulantes , Heparina/efeitos adversos , Antagonistas de Heparina , Humanos , ProtaminasRESUMO
The aim of the present study was to perform an economic evaluation of two alternative assays of ADAMTS13 activity (A Disintegrin And Metalloprotease with ThromboSpondin type 1 repeats, member 13) for diagnosing thrombotic thrombocytopenic purpura (TTP) in the Hospital of Lyon (France). The study approach was more economic than clinical. We retrospectively calculated the prescription costs of ADAMST13 activity from January to December 2019 for patients depending on the assay: manual ELISA (Technozym) or automated assay (AcuStar Werfen, Instrumentation Laboratory). Then, we compared the cost of therapeutic plasma exchange (TPE) consumption awaiting ADAMTS13 activity assay results. From an economic point of view, the automated assay was more cost-effective. From a clinical one, we supposed that the faster results given by AcuStar could improve patient care by reducing the number of TPEs. Automated assay could improve patient care without increasing costs in our institution.
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Púrpura Trombocitopênica Trombótica , Proteína ADAMTS13 , Análise Custo-Benefício , Hospitais , Humanos , Troca Plasmática , Púrpura Trombocitopênica Trombótica/diagnóstico , Púrpura Trombocitopênica Trombótica/terapia , Estudos RetrospectivosRESUMO
INTRODUCTION: The accurate diagnosis of heparin-induced thrombocytopenia (HIT) is essential to ensure adequate treatment and prevent complications. First step diagnosis test are immunoassays including enzyme-linked immunosorbent assays (ELISAs) and rapid immunoassays. METHODS: Using a Bayesian approach, we prospectively evaluated the performance of the IgG PF4/polyvinylsulfonate ELISA and a chemiluminescent immunoassay (CLIA), which are specific for IgG and use the same antigenic target to detect HIT antibodies. RESULTS: One hundred and eighty-four 184 consecutive patients with an intermediate (n = 159) or high (n = 25) clinical pretest probability of HIT based on the 4Ts score or platelet pattern were included. Both immunoassays (IAs) were performed on all 184 samples, and definite HIT was confirmed with a positive serotonin release assay in 29 patients (12.7%). The sensitivity (Ss) and negative predictive value (NPV) of ELISA were excellent (100%) allowing HIT to be excluded with good confidence when the test was negative. In addition, the Ss and NPV of the CLIA equalled 93.1% and 98.6%, respectively, as it was negative in two definite HIT. When the CLIA was negative, the post-test probability of HIT was 0.7% in case of intermediate risk. Although there was excellent agreement between CLIA and ELISA results, the quantitative values provided by the two IAs were not correlated. CONCLUSION: AcuStar HIT® detects more than 90% of HIT, as do all rapid IAs, and appears to be a good tool for excluding HIT when the pretest probability is intermediate. A chemiluminescent signal higher than 10 IU/mL is highly predictive of definite HIT with a PPV of 100%.
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Anticoagulantes/efeitos adversos , Heparina/efeitos adversos , Imunoglobulina G/sangue , Trombocitopenia/sangue , Trombocitopenia/induzido quimicamente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticoagulantes/imunologia , Teorema de Bayes , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Heparina/imunologia , Humanos , Imunoensaio/métodos , Imunoglobulina G/imunologia , Medições Luminescentes/métodos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Sensibilidade e Especificidade , Trombocitopenia/diagnóstico , Trombocitopenia/imunologia , Adulto JovemRESUMO
Heparin-induced thrombocytopenia (HIT) is a severe complication of heparin therapy caused by an antibody against heparin/Platelet Factor 4 (PF4) complex. It complicates the treatment with unfractionated heparin (UFH). The aim of the study was to assess the interest of using confirmatory test in ELISA with use of high concentration of heparin (100 UI/mL) in patients (n=15) with discordance between platelet activation test and ELISA test. We obtained a rate inhibition higher than 50% in 86% of patients was observed. We conclude that inclusion of the high heparin confirmatory procedure in ELISA demonstrate the dependent heparin character of the antibodies but does not improve diagnostic specificity. In addiction a 2-fold increase in final test cost is observed.
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Ensaio de Imunoadsorção Enzimática/métodos , Heparina/efeitos adversos , Trombocitopenia/induzido quimicamente , Trombocitopenia/diagnóstico , Anticorpos/sangue , Custos e Análise de Custo , Ensaio de Imunoadsorção Enzimática/normas , Heparina/sangue , Humanos , Ativação Plaquetária/efeitos dos fármacos , Sensibilidade e Especificidade , Trombocitopenia/economiaRESUMO
INTRODUCTION: Interference on biological assays due to hemolysis, icterus, or lipemia (HIL) could represent a significant source of analytical errors leading to inaccurate interpretation of results. The aim of this study was to assess the HIL interference on prothrombin time (PT), activated partial thromboplastin time (aPTT), and fibrinogen, using mechanical and optical detection methods. METHODS: Control plasmas and plasmas from patients treated with vitamin K antagonists or unfractionated heparin, with or without HIL, were performed on two analytical detection systems in order to identify potential analytical biases. Whether HIL lead to significant biological interferences was also evaluated, and a cutoff point for HIL-induced analytical bias was determined. RESULTS: Hemolysis influenced PT and aPTT when hemoglobin was at 5 and 1.5 g/L in plasma, respectively. At 1.8 g/L, a positive relationship was found between the bias and the hemoglobin supernatant level only for fibrinogen measurement, using optical detection. For icteric interference, no significant bias was observed until a bilirubin concentration of 30 mg/dL. Lipamia (>500 mg/dL) led to analytical interference when using the optical analyzer. CONCLUSION: The present study detected analytical interferences such as lipemia (>500 mg/dL) on coagulation tests on the optical analyzer. We also found a biological impact on the results in case of hemolyzed sample: Fibrinogen was decreased when the hemoglobin level was superior to 1.8 g/L, PT was prolonged beyond 5 g/L, and aPTT was shortened beyond 1.5 g/L hemoglobin concentration, especially in patients treated with heparin. Above these thresholds, it is important not to give results that could influence the clinical decision.
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Bilirrubina/sangue , Hemólise , Hiperlipidemias/sangue , Feminino , Humanos , Masculino , Tempo de Tromboplastina Parcial/instrumentação , Tempo de Protrombina/instrumentaçãoRESUMO
Laboratories need to set up effective overall management of their internal quality control (IQC) and external quality assessment (EQA) results as key elements in statistical process control. Quality targets need to be defined, with methods to ensure durable control with respect to the relevant specifications. The hemostasis laboratory of the Lyon Hospitals Board (HCL, Lyon, France) uses model 3 from the Milan consensus conference, which is the state of the art in terms of quality targets, and uses a common EQA provider supplying as many real patient samples as possible. Giving priority to adopted methods, the lab optimizes the use of manufacturers' prior data: maximum acceptable inter assay coefficient of variation (CV) and prior IQC target values. Bayesian inference brings the method under control with respect to the manufacturers' prior data without the need for a preliminary phase. It links the IQC and EQA plans by the maximum acceptable CVs defined by the manufacturer.
Assuntos
Testes Hematológicos/estatística & dados numéricos , Testes Hematológicos/normas , Laboratórios Hospitalares/estatística & dados numéricos , Garantia da Qualidade dos Cuidados de Saúde , Teorema de Bayes , Testes de Coagulação Sanguínea/instrumentação , Testes de Coagulação Sanguínea/métodos , Testes de Coagulação Sanguínea/normas , Testes de Coagulação Sanguínea/estatística & dados numéricos , Serviços de Laboratório Clínico/organização & administração , Serviços de Laboratório Clínico/normas , Serviços de Laboratório Clínico/estatística & dados numéricos , França/epidemiologia , Testes Hematológicos/instrumentação , Testes Hematológicos/métodos , Hemostasia/fisiologia , Humanos , Laboratórios Hospitalares/organização & administração , Laboratórios Hospitalares/normas , Ensaio de Proficiência Laboratorial/organização & administração , Ensaio de Proficiência Laboratorial/normas , Ensaio de Proficiência Laboratorial/estatística & dados numéricos , Prática Profissional/organização & administração , Prática Profissional/normas , Prática Profissional/estatística & dados numéricos , Garantia da Qualidade dos Cuidados de Saúde/métodos , Garantia da Qualidade dos Cuidados de Saúde/organização & administração , Garantia da Qualidade dos Cuidados de Saúde/normas , Garantia da Qualidade dos Cuidados de Saúde/estatística & dados numéricos , Controle de Qualidade , Estudos RetrospectivosRESUMO
BACKGROUND: Thirty percent of Covid-19 patients admitted to intensive care units present with thrombotic complications despite thromboprophylaxis. Bed rest, obesity, hypoxia, coagulopathy, and acute excessive inflammation are potential mechanisms reported by previous studies. Better understanding of the underlying mechanisms leading to thrombosis is crucial for developing more appropriate prophylaxis and treatment strategies. OBJECTIVE: We aimed to assess fibrinolytic activity and thrombin generation in 78 Covid-19 patients. PATIENTS AND METHODS: Forty-eight patients admitted to the intensive care unit and 30 patients admitted to the internal medicine department were included in the study. All patients received thromboprophylaxis. We measured fibrinolytic parameters (tissue plasminogen activator, PAI-1, thrombin activatable fibrinolysis inhibitor, alpha2 anti-plasmin, and tissue plasminogen activator-modified ROTEM device), thrombin generation, and other coagulation tests (D-dimer, fibrinogen, factor VIII, antithrombin). RESULTS AND CONCLUSIONS: We observed two key findings: a high thrombin generation capacity that remained within normal values despite heparin therapy and a hypofibrinolysis mainly associated with increased PAI-1 levels. A modified ROTEM is able to detect both hypercoagulability and hypofibrinolysis simultaneously in Covid-19 patients with thrombosis.