Are Screening Tests Reliable to Rule Out Direct Oral Anticoagulant Plasma Levels at Various Thresholds (30, 50, or 100 ng/mL) in Emergency Situations?

International audienc

Are Screening Tests Reliable to Rule Out Direct Oral Anticoagulant Plasma Levels at Various Thresholds (30, 50, or 100 ng/mL) in Emergency Situations?

International audienc

Suivi biologique des patients sous nouveaux anticoagulants oraux:qui, quand, comment ?

Plusieurs anticoagulants oraux directs (non-VKA oral anticoagulants, NOACs) sont maintenant largement utilisés dans la prévention et le traitement de la maladie thromboembolique. Contrairement aux antagonistes de la vitamine K, les NOACs possèdent une pharmacocinétique et une pharmacodynamique prédictibles. C’est pourquoi ils sont administrés le plus souvent à dose fixe sans suivi de la coagulation en routine. Cependant, pour certaines sous-populations ou circonstances cliniques, la mesure de l’exposition au médicament peut être utile : suspicion de surdosage, patients présentant un événement hémorragique ou thrombotique en cours de traitement, patients en insuffisance rénale, ou encore patients nécessitant une chirurgie ou un geste invasif en urgence. Cet article fournit des lignes de conduite pratiques et résume l’influence des NOACs sur les tests classiques de coagulatio

Anticoagulants directs oraux : actualités pour les biologistes

Plusieurs anticoagulants oraux directs (Non-VKA oral anticoagulants, NOAC) sont maintenant largement utilisés dans la prévention et le traitement de la maladie thromboembolique. Contrairement aux antagonistes de la vitamine K, les NOAC possèdent une pharmacocinétique et une pharmacodynamique prédictibles. C’est pourquoi ils sont administrés le plus souvent à dose fixe sans suivi biologique en routine. Cependant, pour certaines sous-populations ou circonstances cliniques, la mesure de l’exposition au médicament peut être utile : suspicion de surdosage, patients présentant un événement hémorragique ou thrombotique en cours de traitement, patients en insuffisance rénale, ou encore patients nécessitant une chirurgie ou un geste invasif en urgence. Cet article fournit des lignes de conduite pratiques et résume l’influence des NOAC sur les tests classiques de coagulation.[Non-VKA oral anticoagulants: An update for the clinical biologists ] Non-VKA oral anticoagulants (NOACs), thanks to their ease of use and their similar or superior safety/efficacy profiles versus warfarin, have now widely reached the lucrative market of anticoagulation. However, while the marketing authorization holders always claim, in a quite unclear way that no monitoring is required, accumulative evidence and cases of major bleeding have been described in the literature and reported by spontaneous reporting systems at the regulator's level. These compounds are usually given at fixed doses without routine coagulation monitoring. However, new data suggests that an assessment of the response at the individual level could improve the benefit-risk ratio of, at least dabigatran. Therefore, in certain patient populations, i.e. acute or chronic renal impairment or multiple drug interactions, measurement of drug exposure may be useful to ensure an optimal treatment response. More specific circumstances such as patients experiencing a haemorrhagic or thromboembolic event during the treatment duration, patients who require urgent surgery or an invasive procedure, or patient with a suspected overdose could benefit from such a measurement. This article aims at providing guidance on how to best estimate the intensity of anticoagulation using laboratory assays in daily practice. © 2015, John Libbey Eurotext. All rights reserved

Real Life Population Pharmacokinetics Modelling of Eight Factors VIII in Patients with Severe Haemophilia A: Is It Always Relevant to Switch to an Extended Half-Life?

International audienc

Factor IX assays in treated hemophilia B patients

International audienceReplacement therapy with plasma-derived or recombinant FIX (pdFIX or rFIX) concentrates is the standard of treatment in patients with hemophilia B. The method predominantly used for measuring factor IX (FIX:C) levels is the one-stage clotting assay (OSA) but this method depends on the activated partial thromboplastin time (APTT) reagent and the coagulation analyzer used, and wide variations in the measurements of FIX recovery have been reported with some factor concentrates. The French study group on the biology of hemorrhagic diseases (a collaborative group of the GFHT and MHEMO network), presents a review of the literature and proposals for the monitoring of FIX:C levels in treated hemophilia B patients. The use of OSA calibrated with a plasma reference tested against the current FIX WHO International Standard is recommended for the monitoring of patients treated with pdFIX or rFIX. Chromogenic substrate assays (CSA) are adequate for the monitoring of patients treated with Rixubis®, but data available for Benefix® are currently too limited. For extended half-life rFIX (EHL-rFIX), large discordances in the FIX:C levels measured were evidenced, depending on the method and reagents used. Great attention is therefore required for measuring FIX:C levels by OSA in patients substituted by EHL-rFIX. Commercial kits for CSA are not equivalent, and although potentially useful, they are not validated for all EHL-rFIX. Most of recent studies reported data obtained with spiked plasmas, which deserve to be confirmed on plasma samples collected in treated patients

Coagulation Characterization of Prothrombin 20209C > T Variant: About 27 New Cases

International audienc

Factor VIII assays in treated hemophilia A patients

International audienceReplacement therapy with plasma-derived or recombinant FVIII (pdFVIII or rFVIII) concentrates is the standard of treatment in patients with hemophilia A. The reference method used for measuring factor VIII (FVIII:C) levels in patients treated by FVIII concentrates is the chromogenic substrate assay (CSA). However, the one-stage clotting assay (OSA) is predominantly used in current clinical practice, but this method depends on the activated partial thromboplastin time (APTT) reagent and the coagulation analyzer used, and wide variations in the measurements of FVIII recovery have been reported with some factor concentrates. The French study group on the biology of hemorrhagic diseases (a collaborative group of the GFHT and MHEMO network) presents a review of the literature and proposals for the monitoring of FVIII:C levels in treated hemophilia A patients. The use of CSA calibrated with a plasma reference tested against the current FVIII WHO (World Health Organization) International Standard is recommended for the monitoring of patients treated with pdFVIII or rFVIII including extended half-life (EHL) rFVIII. OSA are adequate for the monitoring of patients treated with pdFVIII or with most of rFVIII concentrates. However, preliminary comparison with CSA is mandatory before measuring FVIII:C by OSA in patients treated by Refacto AF®. For rFVIII-EHL, OSA are only acceptable for Elocta®. Great caution is therefore required when measuring FVIII:C levels by OSA in patients substituted by other EHL-rFVIII. Indeed, most of recent studies reported data obtained with spiked plasmas, which deserve to be confirmed on plasma samples collected in treated patients