[Show abstract][Hide abstract] ABSTRACT: Introduction:
The aim of this study was to collect data in France in patients with heparin-induced thrombocytopenia who required parenteral anticoagulation and for whom other non-heparin anticoagulant therapies were contraindicated including patients with renal failure, cross-reactivity to danaparoid or at high hemorrhagic risk.
A total of 20 patients, of mean age 72 ± 10 years, were enrolled in this open-label, multicenter clinical study. Exploratory statistical data analysis was performed with descriptive interpretation of intra-individual comparisons using simple univariate statistics.
The diagnosis of HIT was confirmed in 16 subjects by an independent scientific committee. Fourteen patients (70 %) were in an intensive care unit during the course of the study. Patients were treated with argatroban for a mean duration of 8.5 ± 6.1 days. The mean starting dose of argatroban was 0.77 ± 0.45 μg/kg/min. Platelet recovery was rapid. aPTT and anti-IIa activity assays were used to monitor the dose of argatroban. The mean baseline aPTT value was 45.0 ± 9.8 sec and increased to 78.2 ± 35.8 sec two hours after initiating argatroban. At this time mean argatroban concentration was 0.34 ± 0.16 and 0.61 ± 0.28 μg/ml using ECT and TT measurements, respectively. New and/or extended thromboses were reported in 25 % of patients and major bleedings were documented in 15 %. Six patients died due to their underlying medical condition.
Considering its hepatic elimination and its short half-life, argatroban can be considered as a safe therapeutic option in HIT patients at high hemorrhagic risk and with renal failure, particularly in an ICU setting.
Full-text · Article · Nov 2015 · Critical care (London, England)
[Show abstract][Hide abstract] ABSTRACT: We conducted a multicentre study of 101 subjects with Congenital Dysfibrinogenemia (CD) to characterize the incidence of hemorrhagic and thrombotic events as well as complications of pregnancy and surgery. At the time of diagnosis, 10.9% and 13.9% had experienced major bleeding and thrombotic events, respectively. During a mean follow-up of 8.8 years after CD diagnosis, the incidence of major bleeding and of thrombotic events was 2.5 and 18.7 per 1000 patient-years respectively, with estimated cumulative incidences at an age of 50 years of 19.2% and 30.1%. We identified 111 pregnancies with an overall incidence of spontaneous abortions and post-partum hemorrhage of 19.8% and 21.4%, respectively. The risk of post-partum hemorrhage was associated with a previously identified bleeding phenotype (OR 5.8; 95%CI 1.2-28.0). Among 137 surgical procedures analyzed, 9 (6.5%) were complicated by abnormal bleeding. Propositi versus relatives, sex, mutation hotspots, fibrinogen levels and activity:antigen ratios were not associated with the risk of thrombotic or bleeding outcomes. In conclusion, the results of our study, the largest in genotyped CD and the first including long term history, indicate that propositi with CD and their relatives carry not only a high risk of major bleeding, including post-partum hemorrhage, but also of thrombotic event.
[Show abstract][Hide abstract] ABSTRACT: The ristocetin cofactor activity assay (VWF:RCo) is the reference method for assessing von Willebrand factor (VWF) activity but remains difficult to perform, and the coefficient of variation of the method is high (about 20-30%). This study evaluated and compared the performance for measuring the VWF activity of two newly commercialised assays [VWF:Ac Innovance (VWF:Ac) and VWF:RCo Acustar (VWF:RCo Acu)] with the reference VWF:RCo aggregation in 123 pathological plasma samples. The correlation and concordance between both new tests (VWF:RCo-Acu and VWF:Ac) and the reference VWF:RCo were good. The results of the VWF activity to VWF antigen ratio were also comparable whatever the method for the classification of VWF deficiency in all patients. Our results showed that both new tests could replace the "gold standard" VWF:RCo in aggregometry with several benefits: they are fully automated, easier and faster to perform, better adapted to emergency situations if necessary.
Full-text · Article · Aug 2014 · Thrombosis and Haemostasis
[Show abstract][Hide abstract] ABSTRACT: Bernard-Soulier syndrome (BSS) is a rare autosomal recessive bleeding disorder characterized by defects of the GPIb-IX-V complex, a platelet receptor for von Willebrand factor (VWF). Most of the mutations identified in the genes encoding for the GP1BA (GPIbα), GP1BB (GPIbβ), and GP9 (GPIX) subunits prevent expression of the complex at the platelet membrane or more rarely its interaction with VWF. As a consequence, platelets are unable to adhere to the vascular subendothelium and agglutinate in response to ristocetin. In order to collect information on BSS patients, we established an International Consortium for the study of BSS, allowing us to enrol and genotype 132 families (56 previously unreported). With 79 additional families for which molecular data was gleaned from the literature, the 211 families characterized so far have mutations in the GP1BA (28%), GP1BB (28%) or GP9 (44%) genes. There is a wide spectrum of mutations with 112 different variants, including 22 novel alterations. Consistent with the rarity of the disease, 85% of the probands carry homozygous mutations with evidence of founder effects in some geographical areas. This overview provides the first global picture of the molecular basis of BSS and will lead to improve patient diagnosis and management.
[Show abstract][Hide abstract] ABSTRACT: Objective:
To report an unusual case of heparin-induced thrombocytopenia (HIT) with cardiac arrest during hemodialysis (HD).
An 88-year-old man previously treated with HD under enoxaparin for 3 years presented with dizziness and cyanosis at the beginning of HD on 3 consecutive sessions. Even though the dialyzer membrane was changed, he presented with cardiac arrest, from which he recovered quickly. At the same time, the platelet count fell, and HIT was suspected. No thrombosis was found. Anti-PF4/H, IL8, and NAP2 antibodies were negative, but platelet aggregation tests and serotonin-release assay were positive. After implementing HD with danaparoid, the platelet count returned to normal, and the patient remained asymptomatic.
Given the clinical context (low-molecular-weight heparin), complications (cardiac arrest and no thrombosis), and timing (3 years), this was an unusual case of HIT. According to the Naranjo probability scale, the causality of enoxaparin was evaluated as probable. In most reported cases, time to onset was short, clotting occurred in the extracorporeal system, and biological tests, including ELISA (enzyme-linked immunosorbent assay) anti-PF4/heparin, were positive. We found no triggering factor in this case, and given the biological results, a new antigenic target may be involved.
HIT must be considered when acute systemic reactions occur at the beginning of HD sessions, even after several years of HD and with no change of anticoagulant, including low-molecular-weight heparin. The platelet count should be measured immediately after the reaction. The diagnosis is important because of possible cardiac arrest in this context.
Full-text · Article · May 2014 · Annals of Pharmacotherapy
[Show abstract][Hide abstract] ABSTRACT: A rapid lateral flow immunoassay (LFIA) (STic Expert(®) HIT), recently developed for the diagnosis of heparin-induced thrombocytopenia (HIT), was evaluated in a prospective multicentre cohort of 334 consecutive patients. The risk of HIT was estimated by the 4Ts score as low, intermediate and high in 28·7%, 61·7% and 9·6% of patients, respectively. Definite HIT was diagnosed in 40 patients (12·0%) with positive results on both enzyme-linked immunosorbent assay (Asserachrom(®) HPIA IgG) and serotonin release assay. The inter-reader reproducibility of results obtained was excellent (kappa ratio > 0·9). The negative predictive value of LFIA with plasma samples was 99·6% with a negative likelihood ratio (LR) of 0·03, and was comparable to those of the particle gel immunoassay (H/PF4-PaGIA(®) ) performed in 124 cases. Positive predictive value and positive LR were 44·4% and 5·87, respectively, and the results were similar for serum samples. The probability of HIT in intermediate risk patients decreased from 11·2% to 0·4% when the LFIA result was negative and increased to 42·5% when it was positive. In conclusion, the STic Expert(®) HIT combined with the 4Ts score is a reliable tool to rule out the diagnosis of HIT.
Full-text · Article · May 2014 · British Journal of Haematology
[Show abstract][Hide abstract] ABSTRACT: Pregnancy in women with inherited thrombocytopenias is a major matter of concern as both the mothers and the newborns are potentially at risk of bleeding. However, medical management of this condition cannot be based on evidence because of the lack of consistent information in the literature. To advance knowledge on this matter, we performed a multicentric, retrospective study evaluating 339 pregnancies in 181 women with 13 different forms of inherited thrombocytopenia. Neither the degree of thrombocytopenia nor the severity of bleeding tendency worsened during pregnancy, and the course of pregnancy was not different from that of healthy subjects in terms of miscarriages, fetal bleeding and preterm births. The degree of thrombocytopenia in the babies was similar to that in the mother. Only 7 of 156 affected newborns had delivery-related bleeding, but two of them died of cerebral hemorrhage. The frequency of delivery-related maternal bleeding ranged from 6.8 to 14.2% depending on the definition of abnormal blood loss, suggesting that the risk of risk of abnormal blood loss was increased with respect to the general population. However, no mother died or received hysterectomy to arrest bleeding. The search for parameters predicting delivery-related bleeding in the mother suggested that hemorrhages requiring blood transfusion were more frequent in women with history of severe bleedings before pregnancy and with platelet count at delivery lower than 50 x 10(9)/L.
[Show abstract][Hide abstract] ABSTRACT: Les nouveaux anticoagulants oraux (NACO), anti-IIa ou anti-Xa directs, sont destinés à être largement utilisés dans le traitement de la maladie thromboembolique veineuse ou dans la fibrillation atriale en remplacement des antivitamines K (AVK). Comme tout traitement anticoagulant, notamment aux doses dites « curatives », ils sont associés à un risque hémorragique spontané ou provoqué. De plus, une proportion non négligeable de patients traités sera confrontée à la nécessité d’un geste invasif en urgence. Compte tenu de l’absence d’antidote spécifique, les mesures à prendre doivent être définies dans ces situations. Le peu de données disponibles ne permet pas d’émettre des recommandations, mais seulement des propositions qui seront amenées à évoluer en fonction de l’expérience accumulée. Les propositions présentées dans cet article s’appliquent au dabigatran (Pradaxa®) et au rivaroxaban (Xarelto®), les données relatives à l’apixaban et à l’edoxaban étant encore trop peu nombreuses. Pour la chirurgie urgente à risque hémorragique, il est proposé de doser le taux plasmatique du médicament. Des taux inférieurs ou égaux à 30 ng/mL, à la fois pour dabigatran et rivaroxaban, devraient permettre la réalisation d’une chirurgie à risque hémorragique élevé. Au-delà, il est convenu, dans la mesure du possible, de reporter l’intervention en surveillant l’évolution de la concentration du médicament. La conduite à tenir est alors définie selon le NACO et sa concentration. Si le dosage du médicament n’est pas disponible immédiatement, des propositions « dégradées » sur la base de tests usuels, TP et TCA, sont présentées. Ces tests ne permettent cependant pas d’évaluer réellement ni la concentration de médicament, ni le risque hémorragique qui en dépend. En cas d’hémorragie grave dans un organe critique, il est proposé de réduire l’effet du traitement anticoagulant par l’utilisation d’un médicament procoagulant non spécifique en première ligne [concentrés de complexe prothrombinique activé (FEIBA® 30–50 U/kg) ou non activé (CCP 50 U/kg)]. En dehors de cette situation, pour tout autre type d’hémorragie grave, l’administration d’un médicament procoagulant, potentiellement thrombogène chez ces patients, sera discutée en fonction du taux de NACO et des possibilités d’hémostase mécanique.
Full-text · Article · Mar 2014 · Annales francaises d'anesthesie et de reanimation
[Show abstract][Hide abstract] ABSTRACT: Congenital dysfibrinogenemias are characterized by biosynthesis of a structurally abnormal fibrinogen molecule that exhibits reduced functional levels compared with the level of fibrinogen antigen. To date a large number of mutations have been identified in patients with dysfibrinogenemia. Mutations occurring at the thrombin cleavage site (Arg16-Gly17 in the mature alpha-chain) at the amino-terminal end of the fibrinogen alpha chain are a common cause of the disease. These mutations causing abnormal fibrin polymerization are associated with different phenotypes. Here, we report the identification of a novel heterozygous missense mutation of Glycine 17 (Gly17Asp) in a female patient with mild bleeding manifestations, and compare it with other previously reported mutations also resulting in abnormal knob A.
No preview · Article · Dec 2013 · Blood coagulation & fibrinolysis: an international journal in haemostasis and thrombosis
[Show abstract][Hide abstract] ABSTRACT: New direct oral anticoagulants (NOAC), inhibitors of factor IIa or Xa, are expected to be widely used for the treatment of venous thromboembolic disease, or in case of atrial fibrillation. Such anticoagulant treatments are known to be associated with haemorrhagic complications. Moreover, it is likely that such patients on long-term treatment with NOAC will be exposed to emergency surgery or invasive procedures. Due to the present lack of experience in such conditions, we cannot make recommendations, but only propose management for optimal safety as regards the risk of bleeding in such emergency conditions. In this article, only dabigatran and rivaroxaban were discussed. For emergency surgery at risk of bleeding, we propose to dose the plasmatic concentration of drug. Levels inferior or equal to 30 ng/mL for both dabigatran and rivaroxaban, should enable the realization of a high bleeding risk surgery. For higher concentration, it was proposed to postpone surgery by monitoring the evolution of the drug concentration. Action is then defined by the kind of NOAC and its concentration. If the dosage of the drug is not immediately available, proposals only based on the usual tests, PT and aPTT, also are presented. However, these tests do not really assess drug concentration or bleeding risk. In case of severe haemorrhage in a critical organ, it is proposed to reduce the effect of anticoagulant therapy using a nonspecific procoagulant drug (activated prothrombin concentrate, FEIBA, 30-50 U/kg, or non-activated 4-factors prothrombin concentrates 50 U/kg). For any other type of severe haemorrhage, the administration of such a procoagulant drug, potentially thrombogenic in these patients, will be discussed regarding concentration of NACO and possibilities for mechanical haemostasis.
Full-text · Article · Jun 2013 · Archives of cardiovascular diseases
[Show abstract][Hide abstract] ABSTRACT: The Clipperton lagoon in the North Pacific Ocean has been isolated from the surrounding sea for c. 160 years. It has a stratified water column that comprises an oxic and brackish upper water layer (mixolimnion) and a deep sulfuric anoxic saline layer (monimolimnion), separated by a steep pycnocline. Here, we test whether the Clipperton lagoon with its distinctive physico-chemical features, geographic isolation, recent water column stratification, and large nutrient input harbors original microbial communities. The combination of capillary electrophoresis single-strand polymorphism (CE-SSCP) fingerprinting and sequencing of cloned bacterial and archaeal 16S rRNA genes, and functional genes for methanogenesis (mcrA), methanotrophy (pmoA), and sulfate reduction (dsrAB), revealed that microbial communities and pathways were highly stratified down the water column. The mixolimnion contained ubiquitous freshwater clades of Alpha- and Betaproteobacteria, while the pycnocline contained mostly green sulfur bacteria (phylum Chlorobi). Sequences of the upper layers were closely related to sequences found in other aquatic ecosystems, suggesting that they have a strong potential for dispersal and colonization. In contrast, the monimolimnion contained new deeply branching bacterial divisions within the OP11 cluster and the Bacteroidetes, and was the most diverse of the layers. The unique environmental conditions characterizing the deep layers of the lagoon may explain the novelty of the microbial communities found at the Clipperton atoll.
Full-text · Article · Jan 2012 · FEMS Microbiology Ecology
[Show abstract][Hide abstract] ABSTRACT: Heart valve disease (HVD) is frequent in patients with systemic lupus erythematosus (SLE), and the role of antiphospholipid antibodies (aPL) is controversial. Thus, our objective was to estimate the risk of HVD, including Libman-Sacks endocarditis, associated with aPL in patients with SLE.
Studies were selected if they investigated the association between aPL and HVD in SLE patients and if aPL-negative patients were included for comparison. Data sources were MEDLINE, Embase, Cochrane Library, hand search, contact with investigators, and reference lists of studies, without language restrictions. Data on study and patient characteristics, risk estimates, and study quality were independently extracted by 2 investigators. Pooled effect estimates were obtained by using the DerSimonian-Laird method. Of 234 identified abstracts, 23 primary studies (15 cross-sectional, 7 cohort, 1 case-control) met inclusion criteria, including 1656 SLE patients and 508 cases of HVD. Compared with SLE patients without aPL (n=988), the overall pooled odds ratios for HVD and Libman-Sacks endocarditis in aPL-positive patients (n=668) were 3.13 (95% confidence interval, 2.31 to 4.24) and 3.51 (95% confidence interval, 1.93 to 6.38), respectively. The risk of HVD depending on aPL subtypes was the highest for lupus anticoagulant at 5.88 (95% confidence interval, 2.92 to 11.84) and IgG anticardiolipin antibodies at 5.63 (95% confidence interval, 3.53 to 8.97).
Overall, the presence of aPL in SLE patients is significantly associated with an increased risk for HVD including Libman-Sacks endocarditis. The risk conferred by IgG anticardiolipin antibodies is as strong as by lupus anticoagulant. Systematic echocardiographic examinations in SLE patients with aPL should be performed.
[Show abstract][Hide abstract] ABSTRACT: Earlier in vitro studies suggested a putative role for the plasma phospholipid transfer protein (PLTP) in the modulation of blood coagulation. The effect of PLTP expression on blood coagulation under both basal and oxidative stress conditions was compared here in wild-type and PLTP-deficient (PLTP-/-) mice.
Under basal conditions, PLTP deficiency was associated with an extended tail bleeding time despite a significant depletion of vascular α-tocopherol content and an impairment of endothelial function. When acute oxidative stress was generated in vivo in the brain vasculature, the steady state levels of oxidized lipid derivatives, the extent of blood vessel occlusion, and the volume of ischemic lesions were more severe in wild-type than in PLTP-/- mice.
In addition to its recognized hyperlipidemic, proinflammatory, and proatherogenic properties, PLTP increases blood coagulation and worsens the extent of ischemic lesions in response to acute oxidative stress. Thus, PLTP arises here as a cardiovascular risk factor for the late thrombotic events occurring in the acute phase of atherosclerosis.
Full-text · Article · Dec 2010 · Arteriosclerosis Thrombosis and Vascular Biology
[Show abstract][Hide abstract] ABSTRACT: We undertook a survey of French university hospital hematological laboratories to ascertain the clinical characteristics of patients with suspected HIT, the laboratory tests performed, and the therapeutic strategy adopted in current practice.
A standardized medical records database for patients with suspected HIT was sent to 19 laboratories. During two months, all consecutive patients for whom a biological test was performed were included.
169 patients were included, 27 (16%) patients having a final diagnosis of HIT. At the time HIT was suspected, the heparin duration and the level of thrombocytopenia were similar in HIT- positive and HIT-negative groups. The use of unfractionated heparin, a therapeutic heparin dose regimen and the presence of thrombotic complications were significantly more frequent in HIT-positive patients. When the heparin dose regimen was taken into account, only thrombotic complications under a therapeutic dose regimen were significantly increased in HIT-positive patients. Eighty-six percent of patients presented at least one alternative diagnosis of thrombocytopenia without significant difference between the two groups. Laboratory tests were performed after a mean of 0.3days and mainly consisted of antigen assays. At the time HIT was suspected, heparin was stopped in 56 (33%) patients, being replaced mainly by danaparoid. Only three laboratories declared they usually received all the necessary clinical information to establish the likelihood of HIT.
In current practice in France, the clinical probability of HIT is rarely established, leading to systematic requests for laboratory HIT tests.
No preview · Article · Feb 2010 · Thrombosis Research
[Show abstract][Hide abstract] ABSTRACT: The frequency of the syndrome of hyperemesis gravidarum (HG) varies from 0.1 to 2% according to the literature. The complications are generally benign. Some of them can compromise the life outcome. Only two cases of HG with bleeding disorder (major epitasis) related to a vitamin K deficiency were previous reported. Here is described a third case related to a vitamin deficiency K. It is characterized by a skin and mucosa haemorrhage (gingivorrhagias; bleeding in urine; bruises at the points of puncture) and by the necessity to treat her in emergency with fresh frozen plasma before intravenous vitamin K as soon as the diagnosis of vitamin K deficiency was done. The indication of the use of frozen fresh plasma is discussed.
No preview · Article · Jul 2009 · Annales francaises d'anesthesie et de reanimation
[Show abstract][Hide abstract] ABSTRACT: Prognostic factors for unfavorable clinical outcome in patients with heparin-induced thrombocytopenia (HIT) are largely unknown.
In this multicenter, retrospective, case-control study, all HIT patients were treated with danaparoid. Study cases were HIT patients with an unfavorable clinical outcome. Controls were HIT patients who were not study cases. Unfavorable clinical outcome was defined as the occurrence of at least one of the following clinical events: death within 60 days after HIT start date, or venous or arterial thromboembolism, amputation, major bleeding, or disseminated intra-vascular coagulation between 48 hours and 60 days after HIT start date.
Compared with controls (n=65), thrombotic episodes within 48 hours of HIT start date were more frequent (59.2% versus 32.3%; p=0.004), the median time between HIT start date and initiation of danaparoid infusion was longer (3.0 versus 1.0 days; p=0.001), and this treatment was more frequently underdosed (43.8% versus 18.8%; p=0.004) in study cases (n=49). Upon multivariate analysis, all these three parameters were significant predictive factors for unfavorable clinical outcome. The adjusted odds ratios [95% confidence interval] were 6.6 [2.5-17.3] for time between HIT start date and danaparoid initiation over 48 hours, 4.3 [1.5-12.0] for danaparoid underdosing, and 3.2 [1.3-8.0] for presence of a thromboembolic episode at HIT start date.
This study supports the recommendations concerning the management of HIT patients, namely discontinuation of all heparin administration once the diagnosis is suspected and prompt initiation of an alternative anticoagulant drug with a strict adherence to doses specifically recommended for these patients.
No preview · Article · May 2009 · Thrombosis Research
[Show abstract][Hide abstract] ABSTRACT: The association of a thrombo-embolic venous disease and multiple osteonecroses occurring in the presence of biological risk factors for thrombosis is rarely described in the literature. We report here the case of a 35-year old patient with such clinical manifestations. This patient is heterozygous for a novel mutation of the protein C gene (N102S) and for FV Leiden polymorphism. The clinical history is characterized by numerous thrombo-embolic venous episodes associated with several episodes of epiphysis osteonecrosis requiring two hip total prostheses and two knee total prostheses. The particular clinical features here are the multiple osteonecroses and the unusual localisation of brain and genital thromboses. The absence of both venous thromboembolic and osteonecrosis events in the relatives presenting the same genetic pattern suggests broad phenotype variations in the clinical expression of these genetic abnormalities. In osteonecrosis associated with thrombophilia, some authors have proposed treatment with stanazolol, which increase circulating protein C concentration. The effectiveness of this drug among such patients should be evaluated by clinical studies.
No preview · Article · Jul 2008 · Annales de biologie clinique