RESUMO
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.
RESUMO
Variant identification underlying inherited dysfibrinogenemia quite exceptionally fails. We report on two dysfibrinogenemia cases whose underlying DNA variant could not be identified by Sanger analysis. These failures result from two distinct mechanisms. The first case involved raw signal overcorrection by a built-in software, and the second constituted the first description of mosaicism for one of the fibrinogen genes. This mosaicism was subsequently identified by next-generation sequencing reanalysis of the sample.
Assuntos
Afibrinogenemia , Mosaicismo , Humanos , Afibrinogenemia/diagnóstico , Afibrinogenemia/genética , Mutação de Sentido Incorreto , Algoritmos , MutaçãoRESUMO
BACKGROUND: Numerous mutations in FGA, FGB or FGG lead to congenital fibrinogen disorders (CFDs), but their epidemiology is not well characterized. The aim of this study was to evaluate the molecular epidemiology of CFD and to develop a genotyping strategy. METHODS: Genetic data from 266 unrelated CFD patients genotyped at our laboratory and from a CFD open access database (n = 1,142) were evaluated. We developed a step-wise screening strategy for the molecular diagnosis of CFD and prospectively tested this strategy on 32 consecutive CFD probands. RESULTS: We identified 345 mutated alleles overall, among 187 heterozygous, 63 homozygous and 16 compound heterozygous individuals. Afibrinogenemia was almost always caused by null mutations (98.6%), mainly in FGA (85%). Hypofibrinogenemia was mainly caused by missense mutations of FGB or FGG (54.2%). Dysfibrinogenemia was almost always caused by heterozygous missense mutations (99.3%) in FGA and FGG. Hotspot mutations were prevalent among quantitative (33.1%) and qualitative fibrinogen disorders (71.1%). The mutational cluster at our laboratory was similar with that reported in the CFD open access database. The proposed step-wise genetic screening strategy proved efficient in both the development and validation samples for CFD: the screening of FGA exons 2, 4, 5 and FGG exon 8 and search for the 11 kb deletion of FGA led to the identification of approximately 80% of mutated alleles, including 15 new mutations. CONCLUSION: The described molecular epidemiology of CFD is complex. The proposed step-wise genetic screening strategy may provide an efficient way to identify causative mutations analysing a minimal number of exons.
Assuntos
Afibrinogenemia/epidemiologia , Fibrinogênio/genética , Genótipo , Mutação/genética , Adolescente , Adulto , Afibrinogenemia/genética , Alelos , Criança , Pré-Escolar , Análise Mutacional de DNA , Feminino , Testes Genéticos , Hemostasia/genética , Humanos , Masculino , Epidemiologia Molecular , Estudos Prospectivos , Suíça/epidemiologia , Adulto JovemAssuntos
Descolamento Prematuro da Placenta/tratamento farmacológico , Afibrinogenemia/tratamento farmacológico , Aspirina/uso terapêutico , Fibrinogênio/genética , Genótipo , Heparina de Baixo Peso Molecular/uso terapêutico , Mutação/genética , Complicações Hematológicas na Gravidez/tratamento farmacológico , Descolamento Prematuro da Placenta/diagnóstico , Afibrinogenemia/diagnóstico , Cesárea , Consanguinidade , Feminino , Fibrinogênio/uso terapêutico , Humanos , Gravidez , Complicações Hematológicas na Gravidez/diagnóstico , Resultado da Gravidez , Tempo de Trombina , Adulto JovemRESUMO
OBJECTIVES: To define the underlying cause of bisalbuminaemia in an individual presenting with spontaneous venous thrombosis. METHOD: Plasma was examined by electrospray time-of-flight mass spectrometry (TOF MS) to assess albumin mutations and to quantify variant expression level. Tryptic peptide mapping and DNA sequencing were used to precisely define the mutation. RESULTS: Whole protein MS indicated a 19Da increase in the mass of 50% of the albumin molecules suggesting a HisâArg substitution. A novel heterozygous 510HisâArg mutation was identified by peptide mass mapping and confirmed by DNA sequencing of exon 12 of the albumin gene. CONCLUSION: The nature and location of the mutation suggest it would have no direct influence on haemostasis through altered warfarin binding or increased fibrinogen attachment and it appears to be incidental to the thrombotic phenotype. However the highly conserved His510 residue is recognised as being of critical importance in albumin recycling through interaction with its savaging neonatal Fc receptor. The normal albumin level of 41.1g/l and the coequal expression of albumin Lyon demonstrate that the conservative 510HisâArg substitution does not interfere with the pH dependant capture and release of albumin by the receptor.
Assuntos
Biomarcadores/análise , Transtornos das Proteínas Sanguíneas/genética , Mutação/genética , Mapeamento de Peptídeos/métodos , Albumina Sérica/análise , Espectrometria de Massas por Ionização por Electrospray/métodos , Transtornos das Proteínas Sanguíneas/sangue , Feminino , Heterozigoto , Antígenos de Histocompatibilidade Classe I/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Receptores Fc/metabolismo , Análise de Sequência de DNA/métodos , Albumina Sérica/genética , Albumina Sérica/metabolismoRESUMO
BACKGROUND AND PURPOSE: The purpose of this study was to systematically determine the correlations between the post-thrombolytic changes of hemostasis parameters and the occurrence of early intracerebral hemorrhage (ICH). METHODS: In 72 consecutive patients with cerebral infarcts treated with rt-PA, plasma levels of fibrinogen, plasminogen, alpha2-antiplasmin, factor XIII, fibrin(ogen) degradation products (FDPs) and d-Dimers were measured at baseline, 2 and 24h after thrombolysis. Correlations were studied between the hemostasis events and early (less than 24h) hemorrhagic infarcts (HIs) or parenchymatous hematomas (PH). RESULTS: Of 72 patients, 6 patients (8.3%) had early PHs, 11 (15.3%) had early HIs, and 55 (76.4%) had no bleeding. Early HIs were not linked to any hemostasis parameter at any time. Univariate comparison of patients having early PHs with non-bleeding patients showed hemostasis abnormalities at 2h: high FDP (p=0.01), high Log FDP (p=0.01), low fibrinogen (p=0.01), and low Log fibrinogen (p=0.01). Logistic regression adjusted for age, NIHSS and diabetes confirmed these 2hour predictors: Log FDP (OR: 7.50; CI: 1.26 to 44.61, p=0.03), and Log fibrinogen (OR: 19.32; CI: 1.81 to 205.98, p=0.01). The decrease in fibrinogen less than 2g/L multiplies the odds of early PH by a factor 12.82. CONCLUSION: An early fibrinogen degradation coagulopathy involving an increase of FDP and a massive consumption of circulating fibrinogen is predictive of early parenchymal hematomas, indicating the occurrence of a particularly intense lysis of circulating fibrinogen. These results, if confirmed by future studies, suggest that early assays of fibrinogen and FDP may be useful in predicting the risk of post-thrombolytic intracerebral hematoma.
Assuntos
Infarto Encefálico/tratamento farmacológico , Hemorragia Cerebral/diagnóstico , Coagulação Intravascular Disseminada/diagnóstico , Produtos de Degradação da Fibrina e do Fibrinogênio/análise , Fibrinolíticos/efeitos adversos , Hematoma/diagnóstico , Terapia Trombolítica/efeitos adversos , Ativador de Plasminogênio Tecidual/efeitos adversos , Idoso , Hemorragia Cerebral/induzido quimicamente , Coagulação Intravascular Disseminada/induzido quimicamente , Feminino , Hematoma/induzido quimicamente , Hemostasia , Humanos , Masculino , Pessoa de Meia-Idade , PrognósticoRESUMO
BACKGROUND: Little is known, in man, in the post-thrombolytic molecular dynamics of haemostasis, particularly the effect of rt-PA on antifibrinolytic components such as alpha2 anti-plasmin and Factor XIII. AIMS AND HYPOTHESIS: The purpose of this study was to systematically determine changes in coagulation and fibrinolytic parameters after thrombolysis with rt-PA during 24h. We also aimed to correlate these parameters with different acute ischemic stroke subtypes and global outcome. METHODS: Eighty consecutive patients with cerebral infarcts treated with rt-PA had their plasma levels of fibrinogen, plasminogen, alpha2-antiplasmin, Factor XIII, fibrin(ogen) degradation products (FDP) and D-Dimers measured at baseline (h0), 2 (h2) and 24h (h24) after initiation of thrombolysis. Correlations between the variations of these components were statistically studied, using the Spearman rank test or the Pearson test. These haemostatic parameters were also compared with cardioembolic and non cardioembolic patients, as well as between poor and favourable outcome patients. RESULTS: Between h0 and h2, a decrease in fibrinogen, plasminogen, alpha2-antiplasmin, and factor XIII was observed, while an increase in FDP and D-Dimers took place. These values returned to the initial levels at h24. At 2h, the decrease in fibrinogen was significantly correlated with that of plasminogen (0.48, p=0.01), alpha2-antiplasmin (0.48, p=0.004), and factor XIII (0.44, p=0.01); the decrease in plasminogen was significantly correlated with those of antifibrinolytic components, factor XIII (0.47, p=0.02) and alpha2-antiplasmin (r=0.77, p<0.001). These variations were independent of NIHSS. Cardioembolic infarcts showed a statistically significant greater h0-h2 decrease in plasminogen (p=0.04) and an h0-h2 increase in FDP (p=0.02). Poor outcome was linked to low plasminogen values at 2 and 24h. CONCLUSIONS: Supposed to be fibrin-specific, rt-PA induces a decrease in circulating fibrinogen, significantly linked to a decrease in plasminogen. A collateral increase in antifibrinolytic agents such as factor XIII and alpha2-antiplasmin is also observed. At 2h, a significant decrease in plasminogen and a significant increase in fibrin(ogen) degradation products (FDP) are observed in cardioembolic infarcts, and appear as early independent predictors of this aetiology. A low plasminogen value at 2h is potentially predictive of poor prognosis at 3months.
Assuntos
Antifibrinolíticos/uso terapêutico , Infarto Cerebral/sangue , Infarto Cerebral/tratamento farmacológico , Fibrinolíticos/uso terapêutico , Hemostasia/efeitos dos fármacos , Ativador de Plasminogênio Tecidual/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Fator XIII/metabolismo , Feminino , Fibrina/metabolismo , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Fibrinogênio/metabolismo , Formicinas/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Plasminogênio/metabolismo , Ribonucleotídeos/sangue , Terapia Trombolítica/métodos , Fatores de Tempo , Resultado do Tratamento , alfa 2-Antiplasmina/metabolismoRESUMO
BACKGROUND: We investigated the relationship between von Willebrand factor (vWF), fibrin monomers (FM), fibrinogen baseline levels and the presence of susceptibility vessel sign (SVS) on T2*-weighted gradient echo imaging in acute ischemic stroke. METHODS: SVS was assessed at admission using T2*-weighted GRE. Plasmatic levels of vWF, FM and fibrinogen were evaluated before the initiation of intravenous thrombolysis. RESULTS: Forty-four patients were enrolled in this study. SVS was noted in 26 patients. Univariate analysis revealed that vWF >160% (p = 0.02) and fibrinogen >4 g/l (p = 0.03) were associated with a significant decrease in the likelihood of SVS. Multivariate analysis confirmed that higher levels of vWF or fibrinogen predicted the absence of SVS. CONCLUSIONS: The increased activity of vWF may promote a fibrin-platelet recruitment mainly contributing to the absence of (SVS).
Assuntos
Isquemia Encefálica/patologia , Fibrina/metabolismo , Fibrinogênio/metabolismo , Acidente Vascular Cerebral/patologia , Fator de von Willebrand/metabolismo , Idoso , Biomarcadores/sangue , Isquemia Encefálica/sangue , Isquemia Encefálica/terapia , Angiografia Cerebral , Feminino , Humanos , Angiografia por Ressonância Magnética , Imageamento por Ressonância Magnética , Masculino , Análise Multivariada , Índice de Gravidade de Doença , Acidente Vascular Cerebral/sangue , Acidente Vascular Cerebral/terapia , Terapia Trombolítica , Resultado do TratamentoRESUMO
This work describes a dysfibrinogenemia linked to a new mutation in the gene coding for fibrinogen γ chain. Dysfibrinogenemia was fortuitously discovered in a 9-year old boy consulting for symptoms suggesting meningitis. DNA was extracted from blood, the fibrinogen genes coding for Aα, Bß and γ chains were sequenced, and compared with consensus sequences. Apart from the patient, dysfibrinogenemia and the mutation p.H103N in the γ chain of fibrinogen with heterozygous status were found in his mother, without any symptom. This mutation is unknown in fibrinogen variant databases and seems to affect mostly fibrin polymerisation. The reporting of this new p.H103N mutation in the γ chain has a great interest for improving the knowledge of the fibrinogen gene and its expression. Even if no haemorrhage was observed in this case, the expression of this mutation impaired the function of the molecule, particularly polymerisation, and could induce bleeding during an important surgery.
Assuntos
Afibrinogenemia/genética , Asparagina/genética , Fibrinogênio/genética , Histidina/genética , Mutação/genética , Adenina , Criança , Códon/genética , Citosina , Exantema Súbito/diagnóstico , Fibrinogênios Anormais/genética , Herpesvirus Humano 6/isolamento & purificação , Heterozigoto , Humanos , Achados Incidentais , Masculino , Polimorfismo Genético/genéticaRESUMO
Detrimental inflammation of the lungs is a hallmark of severe influenza virus infections. Endothelial cells are the source of cytokine amplification, although mechanisms underlying this process are unknown. Here, using combined pharmacological and gene-deletion approaches, we show that plasminogen controls lung inflammation and pathogenesis of infections with influenza A/PR/8/34, highly pathogenic H5N1 and 2009 pandemic H1N1 viruses. Reduction of virus replication was not responsible for the observed effect. However, pharmacological depletion of fibrinogen, the main target of plasminogen reversed disease resistance of plasminogen-deficient mice or mice treated with an inhibitor of plasminogen-mediated fibrinolysis. Therefore, plasminogen contributes to the deleterious inflammation of the lungs and local fibrin clot formation may be implicated in host defense against influenza virus infections. Our studies suggest that the hemostatic system might be explored for novel treatments against influenza.
Assuntos
Antivirais/farmacologia , Fibrinolíticos/farmacologia , Inflamação/induzido quimicamente , Infecções por Orthomyxoviridae/tratamento farmacológico , Plasminogênio/farmacologia , Pneumonia Viral/tratamento farmacológico , Animais , Feminino , Fibrina/efeitos dos fármacos , Tempo de Lise do Coágulo de Fibrina , Fibrinogênio/efeitos dos fármacos , Fibrinólise/efeitos dos fármacos , Interações Hospedeiro-Patógeno , Inflamação/prevenção & controle , Vírus da Influenza A Subtipo H1N1/patogenicidade , Virus da Influenza A Subtipo H5N1/patogenicidade , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Infecções por Orthomyxoviridae/prevenção & controle , Plasminogênio/deficiência , Plasminogênio/genética , Pneumonia Viral/prevenção & controle , Replicação Viral/efeitos dos fármacosAssuntos
Afibrinogenemia/induzido quimicamente , Fibrinolíticos/efeitos adversos , Hemorragias Intracranianas/induzido quimicamente , Acidente Vascular Cerebral/tratamento farmacológico , Terapia Trombolítica/efeitos adversos , Ativador de Plasminogênio Tecidual/efeitos adversos , Afibrinogenemia/sangue , Afibrinogenemia/diagnóstico , Idoso , Biomarcadores/sangue , Regulação para Baixo , Feminino , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Humanos , Hemorragias Intracranianas/sangue , Hemorragias Intracranianas/diagnóstico , Masculino , Plasminogênio/metabolismo , Índice de Gravidade de Doença , Fatores de Tempo , alfa 2-Antiplasmina/metabolismoRESUMO
Analyses of site-directed fibrinogen mutants expressed in several recombinant models have previously shown that both inter- and intra-chain disulfide bonds are critical for fibrinogen assembly and secretion. Four naturally occurring mutations on AαCys36 and AαCys45 residues are reported here to be associated with decreased fibrinogen levels. This confirms the main role of the AαCys36-BßCys65 and AαCys45-γCys23 disulfide bonds in reaching a normal fibrinogen plasma level. Decreased coagulant/antigen ratios indicate abnormal species secretion in heterozygous subjects which varies between individuals. However, in contrast to overexpression in experimental models, disruption of the AαCys36-BßCys65 disulfide bond did not result in the appearance of Aα-Bß-γ moieties in vivo. A 188 kDa molecule reacting only with anti Aα and anti Bß chains was found in the plasma of the AαCys45Tyr variant. Heterozygous carriers of Aα chain mutations usually have normal fibrinogen levels, in contrast to the AαCys36Gly, AαCys36Arg and AαCys45Tyr variants that are shown here to cause hypofibrinogenemia.
Assuntos
Dissulfetos/química , Fibrinogênio/química , Adulto , Substituição de Aminoácidos , Dissulfetos/metabolismo , Feminino , Fibrinogênio/genética , Fibrinogênio/metabolismo , Heterozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Moleculares , Mutação/genética , Polimorfismo Genético , Conformação ProteicaAssuntos
Afibrinogenemia/complicações , Fibrinogênio/administração & dosagem , Hematoma Subdural Intracraniano/prevenção & controle , Ferimentos e Lesões/prevenção & controle , Afibrinogenemia/congênito , Hematoma Subdural Intracraniano/diagnóstico por imagem , Hematoma Subdural Intracraniano/terapia , Humanos , Recém-Nascido , Masculino , Radiografia , Ferimentos e Lesões/diagnóstico por imagemRESUMO
Congenital factor XIII deficiency is a very rare bleeding disorder. Patients with severe FXIII deficiency usually exhibit severe bleeding diatheses. Factor XIII is also involved in maintaining pregnancy, and women with factor XIII deficiency have a high risk of spontaneous abortions. We report here the case of a patient with a mild bleeding history before her pregnancy but who had three spontaneous haemorrhagic miscarriages. The patient was homozygous for G 501 R mutation of the factor XIII A subunit gene. We also detected a coinherited heterozygous factor V Leiden mutation, probably leading to a milder bleeding tendency. The patient had successful factor XIII replacement therapy throughout her fourth pregnancy. The efficacy of the factor XIII infusions was monitored using thromboelastometry and routine factor XIII measurements. This case report shows that factor XIII deficiency should be ruled out in patients with recurrent fetal loss but with a normal miscarriage workup, even in the absence of a history of severe bleeding since childhood. We also showed that thromboelastometry could be a valuable tool for the monitoring of factor XIII replacement therapy.
Assuntos
Aborto Habitual/tratamento farmacológico , Aborto Habitual/genética , Deficiência do Fator XIII/tratamento farmacológico , Fator XIII/administração & dosagem , Fator XIII/metabolismo , Monitorização Fisiológica/métodos , Mutação de Sentido Incorreto , Aborto Habitual/sangue , Adulto , Deficiência do Fator XIII/sangue , Deficiência do Fator XIII/genética , Feminino , Humanos , Gravidez , Tromboelastografia/métodosAssuntos
Afibrinogenemia/genética , Coagulação Sanguínea/genética , Fibrinogênio/genética , Mutação , Adulto , Afibrinogenemia/sangue , Afibrinogenemia/diagnóstico , Testes de Coagulação Sanguínea , Análise Mutacional de DNA , Feminino , Fibrinogênio/química , Fibrinogênio/metabolismo , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Moleculares , Linhagem , Fenótipo , Gravidez , Conformação ProteicaRESUMO
A new case of familial plasmin inhibitor (alpha2 antiplasmin) deficiency is reported. The bleeding symptoms are moderate, happening after surgery or trauma or consisting of abnormal uterine bleeding induced by hormone replacement therapy. It is easily corrected with tranexamic acid. Gene sequencing makes it possible to find a splicing donor site mutation of intron 6, leading to exon 6 skipping. Neither a shortened variant nor an abnormal plasmin interaction was found in plasma by immunoblotting, and fibrin binding is unaffected. The mutation is heterozygous, associated with an intermediate decrease of both antiplasmin activity and antigen levels, and was found in four other family members out of five tested. It is different from the five mutations previously reported. At the time of diagnosis, the patient was living in Artas, France, allowing the defect to be named plasmin inhibitor (alpha2 antiplasmin) Artas.
Assuntos
Hemorragia/genética , Mutação Puntual , Sítios de Splice de RNA/genética , alfa 2-Antiplasmina/genética , Saúde da Família , Feminino , Hemorragia/tratamento farmacológico , Heterozigoto , Humanos , Íntrons , Pessoa de Meia-Idade , Ácido Tranexâmico/uso terapêutico , alfa 2-Antiplasmina/análise , alfa 2-Antiplasmina/deficiênciaAssuntos
Fator V/fisiologia , Hemoglobinopatias/complicações , Hemoglobinas Anormais/genética , Trombose Venosa/genética , Idoso , Substituição de Aminoácidos , Fator V/genética , Saúde da Família , Feminino , França , Variação Genética , Hemoglobinopatias/genética , Heterozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Trombose Venosa/sangue , Trombose Venosa/etiologiaRESUMO
There is a lack of well-established criteria for the specific measurement of fibrinolytic parameters. On behalf of the SSC, the subcommittee on Fibrinolysis started a process to develop criteria for the specific measurement of fibrinolytic variables. This report describes the criteria for the specific measurement of plasmin inhibitor activity. In summary, a plasma deficient in plasmin inhibitor should show an activity close to 0%. Plasma containing only the non-plasminogen binding form of plasmin inhibitor should show an activity nearby the activity of a plasma deficient for plasmin inhibitor. Other inhibitors of plasmin, like a 2 -macroglobulin, antithrombin in the presence of heparin, and C1-esterase inhibitor should not interfere in the assay at the level usually found in pathological conditions or at the higher normal level.