Efficacy and safety of a recombinant von Willebrand factor treatment in acquired von Willebrand syndrome in case of bleeding and surgical procedures.

Introduction: Acquired von Willebrand syndrome (AVWS) is a rare haemorrhagic disorder. The prophylaxis and treatment of bleeding before surgery are complex. Since 2018, a new recombinant VWF (rVWF) concentrate that contains no factor VIII (FVIII) but a high amount of high molecular weight VWF multimers has been available in France.

Does the VWF:CB Assay Help to Diagnose von Willebrand Factor Deficiency in Patients With a Bleeding Disorder of Unknown Cause?

Introduction: The entity entitled bleeding disorder of unknown cause (BDUC) qualifies individuals displaying a mild haemorrhagic profile but normal routine coagulation tests. This study was designed to evaluate whether collagen-binding assay for von Willebrand Factor (VWF) measurement (VWF:CB) could allow to diagnose VW disease in such patients.

Methods: A large screening was conducted prospectively in two University Hospitals, using the bleeding assessment tool (BAT) recommended by the International Society of Thrombosis and Hemostasis.

Mepacrine Flow Cytometry Assay for the Diagnosis of Platelet δ-granule Defects: Literature Review on Methods-Towards a Shared Detailed Protocol.

Accurate assessment of platelet secretion is essential for the diagnosis of inherited or acquired platelet function disorders and more specifically in identifying δ-storage pool disease. Mepacrine, a fluorescent dye, specifically accumulates in platelet δ-granules. The mepacrine flow cytometry (mepacrine FCM) assay has been used for more than half a century in the clinical laboratory as a diagnostic tool for platelet δ-granule disorders.

Prothrombin consumption as an indicator of hemorrhagic phenotype in mild platelet function disorders.

Background: The bleeding risk of patients with mild platelet function disorders is difficult to assess and their phenotype remains ill-explored.

Aim: This study was designed to establish a comprehensive biological phenotype of patients with mild platelet function disorders.

Methods: Twenty patients were included with persistent abnormal light transmission aggregometry (LTA).

A French Real-World Evidence Study Evaluating the Efficacy, Safety, and Pharmacokinetic Parameters of rVIII-SingleChain in Patients with Hemophilia A Receiving Prophylaxis.

Background:  rVIII-SingleChain is a recombinant factor VIII (FVIII) with increased binding affinity to von Willebrand factor compared with other FVIII products. rVIII-SingleChain is indicated for the treatment and prevention of bleeding episodes in patients with hemophilia A.

Objectives:  To collect real-world evidence data from patients treated with rVIII-SingleChain to confirm the efficacy and safety established in the clinical trial program and carry out a population pharmacokinetic (PK) analysis.

Antiphospholipid syndrome in patients over 65 years: A comparative study of clinical and biological features and thrombotic relapses.

Objective: The aim of the study was to describe clinical and biological characteristics and thrombotic relapses of patients diagnosed with antiphospholipid syndrome (APS) after the age of 65 years, in comparison with patients diagnosed with APS before 65.

Methods: This retrospective multicenter study was performed to 2005 from 2017 and included patients diagnosed with APS after the age of 65 years, in accordance with Sydney criteria. We compared these patients with APS patients diagnosed before the age of 65 years, and with control thrombotic patients older than 65 years.

Biological, clinical features and modelling of heterozygous variants of glycoprotein Ib platelet subunit alpha (GP1BA) and glycoprotein Ib platelet subunit beta (GP1BB) genes responsible for constitutional thrombocytopenia.

Constitutional thrombocytopenias are rare disorders, often difficult to discriminate from acquired thrombocytopenias. More than 80 genes have been described as being at the origin of these diseases. Among them, several variants of the glycoprotein Ib platelet subunit alpha (GP1BA) and glycoprotein Ib platelet subunit beta (GP1BB) genes, coding for the GpIb-IX-V glycoprotein complex, have been reported in the literature.

Platelet features allow to differentiate immune thrombocytopenia from inherited thrombocytopenia.

Immune thrombocytopenia (ITP) is an acquired bleeding disorder, for which no specific diagnostic test exists. Inherited thrombocytopenia (IT) can mimic ITP and lead to unappropriated management with significant morbidity. Here, in small cohorts of these two disorders, we explored whether platelet sialylation and platelet activation could allow to discriminate the two conditions.

Prostate interventions in patients with mild haemophilia: Safe and feasible.

Introduction: To date, there is no specific recommendation or evaluation of the morbidity of prostate surgery in patients with haemophilia (PWH) although this surgery is common and at high risk of bleeding.

Aim: To assess the post-operative morbidity of benign prostate hyperplasia (BPH) surgeries and of oncological prostate interventions in patients with mild haemophilia A or B.

Methods: We performed a monocentre, epidemiological, in real life study.

Effect of DDAVP on Platelet Activation and Platelet-Derived Microparticle Generation.

Background:  The way by which 1-deamino-8-D-arginine vasopressin (DDAVP) acts on platelets remains unclear. Data from the literature tend to show that there is no definite effect on platelet activation, but recent work has suggested that a subtype of platelets, activated by the combined action of collagen and thrombin, was triggered by DDAVP. Moreover, platelet microparticles (PMPs), which have been shown to be procoagulant, have rarely been studied in this context.

Heparin Anti-Xa Activity, a Readily Available Unique Test to Quantify Apixaban, Rivaroxaban, Fondaparinux, and Danaparoid Levels.

Background: Despite their usefulness in perioperative and acute care settings, factor-Xa inhibitor-specific assays are scarcely available, contrary to heparin anti-Xa assay. We assessed whether the heparin anti-Xa assay can (1) be used as a screening test to rule out apixaban, rivaroxaban, fondaparinux, and danaparoid levels that contraindicate invasive procedures according to current guidelines (>30 ng·mL-1, >30 ng·mL-1, >0.1 µg·mL-1, and >0.

Platelet immunophenotyping in health and inherited bleeding disorders, a review and practical hints.

Inherited platelet function disorders are rare hemorrhagic diseases. The gold standard for their exploration is optical aggregometry; however, investigations by flow cytometry (FCM) are being increasingly used. In this review, the physiology of platelets is first recalled, setting the stage for the compartments of platelets that can be apprehended by specific and appropriate labeling.