Analysis of 339 pregnancies in 181 women with 13 different forms of inherited thrombocytopenia

65Pregnancy 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 did not differ from that of healthy subjects in terms of miscarriages, fetal bleeding and pre-term 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 2 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 abnormal blood loss was increased with respect to the general population. However, no mother died or had to undergo 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 below 50 × 10(9)/L.openopenPatrizia Noris; Nicole Schlegel; Catherine Klersy; Paula G. Heller; Elisa Civaschi; Nuria Pujol-Moix; Fabrizio Fabris; Remi Favier; Paolo Gresele; Véronique Latger-Cannard; Adam Cuker; Paquita Nurden; Andreas Greinacher; Marco Cattaneo; Erica De Candia; Alessandro Pecci; Marie-Françoise Hurtaud-Roux; Ana C. Glembotsky; Eduardo Muñiz-Diaz; Maria Luigia Randi; Nathalie Trillot; Loredana Bury; Thomas Lecompte; Caterina Marconi; Anna Savoia; Carlo L. Balduini; Sophie Bayart; Anne Bauters; Schéhérazade Benabdallah-Guedira; Françoise Boehlen; Jeanne-Yvonne Borg; Roberta Bottega; James Bussel; Daniela De Rocco; Emmanuel de Maistre; Michela Faleschini; Emanuela Falcinelli; Silvia Ferrari; Alina Ferster; Tiziana Fierro; Dominique Fleury; Pierre Fontana; Chloé James; Francois Lanza; Véronique Le Cam Duchez; Giuseppe Loffredo; Pamela Magini; Dominique Martin-Coignard; Fanny Menard; Sandra Mercier; Annamaria Mezzasoma; Pietro Minuz; Ilaria Nichele; Lucia D. Notarangelo; Tommaso Pippucci; Gian Marco Podda; Catherine Pouymayou; Agnes Rigouzzo; Bruno Royer; Pierre Sie; Virginie Siguret; Catherine Trichet; Alessandra Tucci; Béatrice Saposnik; Dino VeneriPatrizia, Noris; Nicole, Schlegel; Catherine, Klersy; Paula G., Heller; Elisa, Civaschi; Nuria Pujol, Moix; Fabrizio, Fabris; Remi, Favier; Paolo, Gresele; Véronique Latger, Cannard; Adam, Cuker; Paquita, Nurden; Andreas, Greinacher; Marco, Cattaneo; Erica De, Candia; Alessandro, Pecci; Marie Françoise Hurtaud, Roux; Ana C., Glembotsky; Eduardo Muñiz, Diaz; Maria Luigia, Randi; Nathalie, Trillot; Loredana, Bury; Thomas, Lecompte; Caterina, Marconi; Savoia, Anna; Carlo L., Balduini; Sophie, Bayart; Anne, Bauters; Schéhérazade Benabdallah, Guedira; Françoise, Boehlen; Jeanne Yvonne, Borg; Bottega, Roberta; James, Bussel; DE ROCCO, Daniela; Emmanuel de, Maistre; Faleschini, Michela; Emanuela, Falcinelli; Silvia, Ferrari; Alina, Ferster; Tiziana, Fierro; Dominique, Fleury; Pierre, Fontana; Chloé, James; Francois, Lanza; Véronique Le Cam, Duchez; Giuseppe, Loffredo; Pamela, Magini; Dominique Martin, Coignard; Fanny, Menard; Sandra, Mercier; Annamaria, Mezzasoma; Pietro, Minuz; Ilaria, Nichele; Lucia D., Notarangelo; Tommaso, Pippucci; Gian Marco, Podda; Catherine, Pouymayou; Agnes, Rigouzzo; Bruno, Royer; Pierre, Sie; Virginie, Siguret; Catherine, Trichet; Alessandra, Tucci; Béatrice, Saposnik; Dino, Vener

Hypercoagulability Evaluation in Antiphospholipid Syndrome without Anticoagulation Treatment with Thrombin Generation Assay: A Preliminary Study

Antiphospholipid syndrome (APS) is associated with thrombotic events (tAPS) and/or obstetrical morbidity (oAPS), with persisting antiphospholipid antibodies (aPL). Despite an update of aPL in 2006, several patients had typical clinical events without the classical biological criteria. The aim of our study was to evaluate the hypercoagulability state with both thrombin generation (TG) profiles and activated protein C resistance (aPCR) in different types of APS. Methods: We retrospectively included 41 patients with Sydney criteria classification (tAPS, oAPS) and no clinical manifestation of APS with persistent aPL (biological APS). A thrombin generation assay was performed with a Fluoroskan Ascent fluorometer in platelet-poor plasma (PPP). Activated protein C resistance was measured as a ratio: ETP+aPC/ETP-aPC × 100. Results: Thrombotic APS and oAPS had an increase of global thrombin generation (ETPcontrol = 808 nM.min (756–853) vs. 1265 nM.min (956–1741) and 1863 nM.min (1434–2080), respectively) (Peakcontrol = 78 nM (74–86) vs. 153 nM (109–215) and 254 nM.min (232–289), respectively). Biological APS had only a lag time increase (Tcontrol = 4.89 ± 1.65 min vs. 13.6 ± 3.9 min). An increased aPCR was observed in tAPS (52.7 ± 16.4%), oAPS (64.1 ± 14.6%) as compared to the control group (27.2 ± 13.8%). Conclusion: Our data suggest an increase of thrombin generation in thrombotic and obstetrical APS and no hypercoagulable states in patients with biological APS. The study of a prospective and a larger controlled cohort could determine the TGA useful for APS monitoring and could confirm an aPCR evaluation in PPP

Acquired hemophilia possibly induced by etanercept in a patient with rheumatoid arthritis

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Development of a thrombin generation test in cultured endothelial cells: Evaluation of the prothrombotic effects of antiphospholipid antibodies

International audienceIntroduction: Circulating antiphospholipid antibodies (APL) induce vascular injury and endothelial dysfunction, which are associated with thrombotic events and/or fetal loss. We developed a model in which calibrated automated thrombin generation (CAT) is carried out in wells lined with cultured endothelial cells. Then we investigated how far b2GP1 antibodies provoked thrombin generation (TG) enhancing effects in these cells and/or in blood platelets. Materials and methods: Thrombin generation induced by different concentrations of tissue factor and different levels of endothelial aortic cell confluence was investigated by calibrated automated thrombogram. Endothelial cells were incubated with the purified anti-β2glycoprotein I antibodies of patients with antiphospholipid syndrome (APS). Platelet free plasma and platelet rich plasma were used to study thrombin generation in en-dothelial cells and platelet reactivity, respectively. Results: Endothelial cell confluence was negatively correlated with thrombin generation which was dependent on the concentration of APL incubated. Activation of endothelial cells with APL significantly increased thrombin generation triggered by PFP. Triggering by PRP increased thrombinogram parameters. Moreover, anti-β2glycoprotein I antibodies incubated with platelet significantly amplified thrombin formation in PRP and induced platelet activation without tissue factor. Conclusion: In this in vitro study, we demonstrate the feasibility of using thrombin generation test in cultured endothelial cells and suggest the need to realize adjustments to standardize results. The mechanism of pro-thrombotic states in APS requires endothelial dysfunction and platelet activation. The quantification of thrombin formation shows that APL incubation induces endothelial injury in cultured cells amplified by platelets

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

Is there a role for the laboratory monitoring in the management of specific antidotes of direct oral anticoagulants?

International audienceGiven the growing number of patients receiving direct oral anticoagulant (DOAC), patients requiring rapid neutralization is also increasing in case of major bleedings or urgent surgery/procedures. Idarucizumab is commercialized as a specific antidote to dabigatran while andexanet alfa has gained the Food and Drug Administration and the European Medicines Agency approval as an oral anti-factor Xa inhibitors antidote. Other antidotes or hemostatic agents are still under preclinical or clinical development, the most advanced being ciraparantag. DOAC plasma levels measurement allows to appropriately select patient for antidote administration and may prevent unnecessary prescription of expensive molecules in some acute clinical settings. However, these tests might be inconclusive after some antidote administration, namely andexanet alfa and ciraparantag. The benefit of laboratory monitoring following DOAC reversal remains unclear. Here, we sought to provide an overview of the key studies evaluating the safety and efficacy of DOAC reversal using the most developed/commercialized specific antidotes, to discuss the potential role of the laboratory monitoring in the management of patients receiving DOAC specific antidotes and to highlight the areas that deserve further investigations in order to establish the exact role of laboratory monitoring in the appropriate management of DOAC specific antidotes

Factor v Leiden homozygous genotype and pregnancy outcomes.

International audienceOBJECTIVE: To assess the rate of early (first trimester) and late (second and third trimester) fetal loss in women who are factor V Leiden homozygous. METHODS: Between December 1995 and February 2007, consecutive, unrelated white women who were factor V Leiden homozygous and who had been pregnant at least once were recruited from 10 French hemostasis units. For reasons of comparison, we included women who were factor V Leiden heterozygous and a group of noncarriers. The frequency of early and late fetal loss was assessed retrospectively and compared among the three groups. The effect of concomitant thrombophilic abnormalities was evaluated. The overall pregnancy outcome was reported. RESULTS: We analyzed 240 thromboprophylaxis-free pregnancies in 95 women who were factor V Leiden homozygous, 425 in 195 women who were factor V Leiden heterozygous, and 182 in 73 women who were noncarriers. The risk of late fetal loss was higher in women who were homozygous (13/95, 13.7%) compared with those who were noncarriers (1/73, 1.4%, odds ratio 11.41, 95% confidence interval 1.46-89.46, P=.002), whereas it was similar in women who were heterozygous and in noncarriers (6/195, 3.1% compared with 1/73, 1.4%, P=.68). The percentage of women with early fetal loss was similar in the three groups (P=.81). The live-birth rate was 80%, 84%, and 85%, respectively, for women who where homozygous, heterozygous, and noncarriers (P=.88). CONCLUSION: The factor V Leiden homozygous genotype increases the risk of late fetal loss. However, the overall likelihood of a positive outcome is high in our series of women who were homozygous. LEVEL OF EVIDENCE: III