[How I explore hémostatic abnormalities in pediatrics]. / Comment j'explore. Une anomalie du bilan d'hémostase en pédiatrie.

Hemostasis work-up is frequently requested in pediatric cares and can often seem complicated to interpret when certain results return to be abnormal. In addition, these biological tests are very sensitive and several pre-analytical conditions can influence them and skew the results, leading to erroneous analyzes and diagnoses. Indeed, systemic inflammation, anemia or even only the delay between blood sampling and analysis can make the results more difficult to be interpreted. However, when the tests have been carried out under good conditions, having in mind a few basic knowledge of hemostasis can easily help to first distinguish a pathology of primary hemostasis from a coagulopathy. Secondly, depending on the abnormal biological tests, complementary oriented assays may then be requested, ideally in a laboratory specialized in hemostasis, in order to confirm or rule out a true hemorrhagic pathology.

Le bilan d'hémostase standard, fréquemment demandé en pédiatrie, peut souvent sembler compliqué à interpréter lorsque certains résultats reviennent anormaux. De plus, l'influence des conditions pré-analytiques, parfois méconnues, sur ces tests biologiques extrêmement sensibles peut en fausser les résultats et entraîner des analyses et des diagnostics erronés. En effet, des paramètres tels que l'inflammation, un contexte d'anémie ou encore un délai trop important entre le prélèvement sanguin et l'analyse peuvent rendre les résultats ininterprétables. Lorsque les tests ont été réalisés dans de bonnes conditions, quelques bases de physiologie de l'hémostase ainsi que quelques spécificités liées à la pédiatrie permettent facilement de s'orienter vers une pathologie de l'hémostase primaire ou de la coagulation. Dans un second temps, en fonction des tests biologiques altérés, des dosages complémentaires orientés peuvent être demandés, idéalement dans un laboratoire spécialisé en hémostase, afin d'affirmer ou infirmer une véritable pathologie hémorragique.

Could Egg White Lysozyme be Solved by Single Particle Cryo-EM?

The combination of high-end cryogenic transmission electron microscopes (cryo-EM), direct electron detectors, and advanced image algorithms allows researchers to obtain the 3D structures of much smaller macromolecules than years ago. However, there are still major challenges for the single-particle cryo-EM method to achieve routine structure determinations for macromolecules much smaller than 100 kDa, which are the majority of all plant and animal proteins. These challenges include sample characteristics such as sample heterogeneity, beam damage, ice layer thickness, stability, and quality, as well as hardware limitations such as detector performance, beam, and phase plate quality. Here, single particle data sets were simulated for samples that were ideal in terms of homogeneity, distribution, and stability, but with realistic parameters for ice layer, dose, detector performance, and beam characteristics. Reference data were calculated for human apo-ferritin using identical parameters reported for an experimental data set downloaded from EMPIAR. Processing of the simulated data set resulted in a value of 1.86 Šfrom 20 214 particles, similar to a 2 Šdensity map obtained from 29 224 particles selected from real micrographs. Simulated data sets were then generated for a 14 kDa protein, hen egg white lysozyme (HEWL), with and without an ideal phase plate (PP). Whereas we could not obtain a high-resolution 3D reconstruction of HEWL for the data set without PP, the one with PP resulted in a 2.78 Šresolution density map from 225 751 particles. Our simulator and simulations could help in pushing the size limits of cryo-EM.

[Hemophilia : a disease on the move]. / Hémophilie : une maladie en marche.

Over the last hundred years, the treatment of hemophilia has evolved considerably. To date, its principle is still to prevent the occurrence of hemorrhages by regular intravenous injections of factor VIII or IX concentrate. It allows to reach a life expectancy similar to the general population. The quality of life is constantly improving despite the constraint imposed by the modality and frequency of injections. The main complication remains the development of antibodies that inhibit the administered factors. Concentrates of long-acting factors are now available allowing to limit for example the frequency of injections. A bispecific monoclonal antibody reproducing the action of factor VIII and injectable subcutaneously has recently become available to hemophilia A patients, with the advantage of being effective even in the presence of inhibitors. Other non-substitute products are being studied offering interesting leads. Finally, gene therapy shows promising results, giving hope for access to this therapeutic option in a relatively near future. These advances are, however, a challenge for clinical laboratories, which must adapt their measurement techniques to ensure optimal monitoring. The future is on its way for hemophilia. Treatment remains expensive but it is worth the price.

Depuis un siècle, le traitement de l'hémophilie a considérablement évolué. À ce jour, son principe est toujours de prévenir la survenue d'hémorragies par injections intraveineuses régulières de concentré de facteur VIII ou IX. Il permet d'atteindre une espérance de vie similaire à la population générale. La qualité de vie est en constante amélioration, malgré la contrainte imposée par les modalités et la fréquence des injections. La complication principale reste le développement d'anticorps inhibant les facteurs administrés. Des concentrés de facteurs à action prolongée sont, maintenant, disponibles et permettent, notamment, de limiter la fréquence des injections. Un anticorps monoclonal bispécifique reproduisant l'action du facteur VIII et injectable par voie sous-cutanée est, depuis peu, à la disposition des patients hémophiles A, avec l'avantage d'être efficace même en présence d'inhibiteurs. D'autres produits non substitutifs sont à l'étude offrant des pistes intéressantes. Enfin, la thérapie génique montre des résultats prometteurs, laissant espérer un accès à cette option thérapeutique dans un futur relativement proche. Ces avancées sont cependant un défi pour les laboratoires d'analyse qui doivent adapter leurs techniques de mesure pour assurer un suivi optimal. Le futur est en marche pour l'hémophilie. Le traitement reste coûteux, mais il en vaut le prix.

[Coagulopathies, thrombotic risk and anticoagulation in COVID-19]. / Coagulopathies, risque thrombotique et anticoagulation dans la COVID-19.

Clinical observations indicate that COVID-19 often provokes coagulopathies, which have been associated with high morbidity and mortality rates. These coagulopathies likely result from Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection-elicited systemic inflammation and endothelial damage. Patients with severe COVID-19 are at high risk of venous and arterial thromboembolic diseases; they can also develop disseminated intravascular coagulation in the most advanced stages of the disease. Medical Organisations on Thrombosis and Hemostasis, among which the Belgian Society on Thrombosis and Haemostasis (BSTH), have formulated recommendations for the prophylaxis and treatment of COVID-19-related venous thromboembolism in ambulatory and hospitalised patients, as well as for the anticoagulation of COVID-19 patients in need of long-term anticoagulation for unrelated cause.These recommendations provide every hospital and primary care physicians with an easy-to-use clinical guidance; they mainly rely on limited level of evidence and are likely to evolve with knowledge of COVID-19 pathophysiology and availability of data from ongoing clinical trials.

Les observations cliniques indiquent qu'une grande proportion des patients atteints de la COVID-19 développent des coagulopathies plus ou moins sévères et associées à un taux élevé de morbidité et de mortalité. Ces troubles de la coagulation seraient liés à l'inflammation systémique et aux lésions endothéliales causées par l'infection par le SARS-CoV-2 («Severe Acute Respiratory Syndrome Coronavirus 2¼). Leur incidence augmente avec la sévérité de la COVID-19. Ils se traduisent par un risque accru de maladies thromboemboliques veineuses (MTEV) ou artérielles ou par le développement d'une coagulation intravasculaire disséminée (CIVD) aux stades cliniques les plus avancés. Les Organisations médicales de Thrombose et Hémostase, parmi lesquelles la Société Belge de Thrombose et Hémostase (BSTH), ont formulé des recommandations pour la prophylaxie et le traitement des MTEV associées à la COVID-19 chez le patient hospitalisé, ambulatoire, et le patient sous traitement anti-thrombotique au moment du développement de la maladie. Ces recommandations ont été rédigées afin de répondre à un besoin médical urgent, de manière adaptée aux soins de santé propres à chaque système local; elles reposent, essentiellement, sur un niveau de preuve limité et sont, dès lors, susceptibles d'évoluer avec une meilleure connaissance de la COVID-19 et la disponibilité des données des essais cliniques en cours.

[Haemophilic ankle arthropathy : case reports and review of the literature]. / Arthropathie hémophilique de la cheville : description de deux cas et revue de la littérature.

Haemophilic arthropathy affects about half of the patients who suffer from haemophilia. Despite the fact that it's one of the main morbidity factors of haemophilia and that the pathophysiology of its mechanism is slowly better understood, its management is still under discussion. The cases of two men (53 and 54 years old) who suffer from ankle haemophilic arthropathy since several years are reported. For both cases, different aspects of the management are investigated, including a medicated and a physiotherapy approach, and an adequate orthotic. Other treatments are available and sometimes used, such as radio- or arthroscopic synovectomy, corticosteroids or platelet-rich plasma in?ltration or visco-supplementation.

L'arthropathie hémophilique affecte environ la moitié des hémophiles. Malgré le fait qu'elle soit un des facteurs principaux de morbidité dans l'hémophilie et que la physiopathologie de ce mécanisme soit de mieux en mieux comprise, sa prise en charge est toujours sujette à discussion. Nous décrivons le cas de deux hommes (âgés de 53 et 54 ans) qui souffrent d'arthropathie hémophilique de cheville depuis plusieurs années. Pour chacun, différents aspects de prise en charge ont été investigués, dont les approches médicamenteuses, rééducatives, et de port d'orthèse adéquate. D'autres prises en charge sont également disponibles et parfois utilisées, comme la radiosynovectomie ou la synovectomie arthroscopique, les in?ltrations par dérivés cortisonés ou de plasma riche en plaquettes (PRP), ou encore une visco-supplémentation.

[Inherited platelet disorders : clinical presentations and diagnostic algorithms]. / Diagnostic différentiel des thrombopénies et thrombopathies constitutionnelles : présentations cliniques et algorithmes décisionnels.

The diagnosis of inherited platelet disorders (IPD) is a complex task. Indeed, due to their rarity, their wide clinical spectrum (intensity of hemorrhagic symptoms) and the need for specialized biological assays (only performed in reference centers) IPDs can be diagnosed very late. However, it is important to remember the crucial need for early diagnosis in order to avoid the use of unnecessary and potentially harmful treatments for the patient. A thorough personal and family history, a complete physical examination and a simple biological work up (blood count, blood smear and platelet occlusion time) will lead to the suspicion of an IPD. It will then be up to the physician to refer the patient to a specialist in order to complete the diagnostic work up and therefore establishing a definitive diagnosis. Here is a description of the most well-known IPDs and their diagnostic algorithms.

Le diagnostic des thrombopénies et thrombopathies constitutionnelles est une tâche complexe. En effet, leur caractère rare, leur hétérogénéité clinique (intensité des symptômes hémorragiques) et la nécessité d'examens complémentaires biologiques spécialisés (uniquement réalisés dans certains centres de référence) expliquent le diagnostic parfois tardif de ces pathologies. Cependant, il convient de rappeler l'importance cruciale d'un diagnostic correct précoce pour éviter le recours à des traitements inutiles et potentiellement néfastes pour le patient en cas de thrombopénie mal diagnostiquée. Une anamnèse personnelle et familiale fouillée, un examen clinique complet et un bilan biologique de base (hémogramme, frottis sanguin et temps d'occlusion plaquettaire) permettront de suspecter une origine congénitale à la thrombopénie que présente un patient. Il reviendra alors au médecin de référer ce dernier à un spécialiste pour la réalisation d'un bilan complet visant à obtenir un diagnostic précis. Nous vous proposons ici une description des thrombopénies et thrombopathies constitutionnelles ainsi que des algorithmes pour leur diagnostic.

[How to explore Inherited platelet disorders]. / Comment j'explore Les thrombopénies et thrombopathies constitutionnelles.

Inherited platelet disorders (IPD) include a set of rare diseases whose diagnosis is often difficult because it requires the use of complex biological assays in specialized centers. They are probably under-diagnosed. Clinicians should consider an IPD when facing a chronic thrombocytopenia resistant to intravenous immunoglobulins (IVIG) and steroids together with a family history of thrombocytopenia. A syndromic thrombocytopenia will be suspected by the family survey and specific clinical signs. The confirmation of the diagnosis will then require the use of specialized biological assays such as platelet aggregation, flow cytometry, electron microscopy, platelet secretion assays, karyotype and molecular biology.

Les thrombopénies et thrombopathies constitutionnelles constituent un ensemble de pathologies rares dont le diagnostic est souvent difficile car il nécessite le recours à des analyses biologiques souvent réservées à des centres spécialisés. Elles sont probablement sous-diagnostiquées. Le clinicien devra les envisager devant une thrombopénie chronique ne répondant pas aux immunoglobulines intraveineuses et aux corticoïdes et la présence d'antécédents familiaux. Une thrombopénie syndromique sera suspectée en fonction des éléments de l'anamnèse familiale et de signes cliniques spécifiques. La confirmation du diagnostic nécessitera la réalisation d'examens biologiques spécialisés (agrégation plaquettaire, cytométrie en flux, microscopie électronique, tests de sécrétion, caryotype et biologie moléculaire).

Misassembly of full-length Disrupted-in-Schizophrenia 1 protein is linked to altered dopamine homeostasis and behavioral deficits.

Disrupted-in-schizophrenia 1 (DISC1) is a mental illness gene first identified in a Scottish pedigree. So far, DISC1-dependent phenotypes in animal models have been confined to expressing mutant DISC1. Here we investigated how pathology of full-length DISC1 protein could be a major mechanism in sporadic mental illness. We demonstrate that a novel transgenic rat model, modestly overexpressing the full-length DISC1 transgene, showed phenotypes consistent with a significant role of DISC1 misassembly in mental illness. The tgDISC1 rat displayed mainly perinuclear DISC1 aggregates in neurons. Furthermore, the tgDISC1 rat showed a robust signature of behavioral phenotypes that includes amphetamine supersensitivity, hyperexploratory behavior and rotarod deficits, all pointing to changes in dopamine (DA) neurotransmission. To understand the etiology of the behavioral deficits, we undertook a series of molecular studies in the dorsal striatum of tgDISC1 rats. We observed an 80% increase in high-affinity DA D2 receptors, an increased translocation of the dopamine transporter to the plasma membrane and a corresponding increase in DA inflow as observed by cyclic voltammetry. A reciprocal relationship between DISC1 protein assembly and DA homeostasis was corroborated by in vitro studies. Elevated cytosolic dopamine caused an increase in DISC1 multimerization, insolubility and complexing with the dopamine transporter, suggesting a physiological mechanism linking DISC1 assembly and dopamine homeostasis. DISC1 protein pathology and its interaction with dopamine homeostasis is a novel cellular mechanism that is relevant for behavioral control and may have a role in mental illness.

Multiple squamous cell carcinomas following introduction of nilotinib.

BACKGROUND: Nilotinib is a second generation tyrosine kinase inhibitor, used in the treatment of chronic myelogenous leukaemia (CML). METHODS: We assessed a 72-year-old woman who was treated with nilotinib for CML. RESULTS: During the year following commencement of nilotinib, the patient developed eight squamous cell carcinomas (SCCs) on her legs. CONCLUSIONS: Development of SCC is a previously unreported adverse reaction to nilotinib.

The mediating role of parenting in the associations between household chaos and children's representations of family dysfunction.

Children's drawings are thought to reflect their mental representations of self and their interpersonal relations within families. Household chaos is believed to disrupt key proximal processes related to optimal development. The present study examines the mediating role of parenting behaviors in the relations between two measures of household chaos, instability and disorganization, and how they may be evidenced in children's representations of family dysfunction as derived from their drawings. The sample (N = 962) is from a longitudinal study of rural poverty exploring the ways in which child, family, and contextual factors shape development over time. Findings reveal that, after controlling for numerous factors including child and primary caregiver covariates, there were significant indirect effects from cumulative family disorganization, but not cumulative family instability, on children's representation of family dysfunction through parenting behaviors. Results suggest that the proximal effects of daily disorganization outweigh the effects of periodic instability overtime.

[Perioperative management of direct oral anticoagulants: not much evidence but several different approaches]. / Gestion péri-opératoire des nouveaux anticoagulants oraux: peu de données mais plusieurs approches!

New oral anticoagulants (NOACs) are a major step forward in the field of anticoagulation. As a consequence, the number of patients treated with NOACs that have to undergo surgery constantly increases. The optimal management of such patients is not clearly determined so far as scientifically established data are lacking. A first proposal is to mimic the perioperative management of patients on vitamin-K antagonists. When the risk of perioperative bleeding is low, NOAC intake is stopped 24 hours before surgery. If the risk of postoperative hemorrhage is moderate or high, NOAC treatment is interrupted 5 days before surgery with a low molecular weight heparin bridging whenever necessary. A second option is based on pharmacokinetic data. When the risk of perioperative bleeding is low, NOAC intake is stopped the day before surgery. If the risk of perioperative bleeding is higher, NOAC intake is suspended for 5 half lives before surgery, 48-72 hours or more. This interruption should be for a longer period in the presence of renal failure. When an unforeseen surgery is needed, the procedure must be delayed as late as possible. In case of emergency, non specific pro-hemostatic agents such as prothrombin complexes or recombinant factor VIIa have not strongly proven useful and must only be used in last ditch effort.

Depletion of epithelial stem-cell compartments in the small intestine of mice lacking Tcf-4.

Mutations of the genes encoding APC or beta-catenin in colon carcinoma induce the constitutive formation of nuclear beta-catenin/Tcf-4 complexes, resulting in activated transcription of Tcf target genes. To study the physiological role of Tcf-4 (which is encoded by the Tcf7/2 gene), we disrupted Tcf7/2 by homologous recombination. Tcf7/2-/- mice die shortly after birth. A single histopathological abnormality was observed. An apparently normal transition of intestinal endoderm into epithelium occurred at approximately embryonic day (E) 14.5. However, no proliferative compartments were maintained in the prospective crypt regions between the villi. As a consequence, the neonatal epithelium was composed entirely of differentiated, non-dividing villus cells. We conclude that the genetic program controlled by Tcf-4 maintains the crypt stem cells of the small intestine. The constitutive activity of Tcf-4 in APC-deficient human epithelial cells may contribute to their malignant transformation by maintaining stem-cell characteristics.

[Clinical case of the month. Extended portal vein thrombosis in patient on vitamin K antagonists]. / Thrombose portale étendue chez un patient sous anti-vitamine K.

There is a long-recognized association between cancer and venous thromboembolism. Venous thrombosis is the most common paraneoplastic complication. We describe a case of rupture of esophageal varices in a patient with a paraneoplastic portal thrombosis. We highlight the links between venous thromboembolism and cancer and also discuss treatment and prognostic factors.

[Oral anticoagulants: new horizons]. / Anticoagulants oraux: nouveaux horizons.

Anticoagulation is at the dawn of a new era. Dominated for a long time by heparins and vitamin K antagonists, the anticoagulant arsenal is growing up. With a direct and reversible action targeting specifically thrombin (IIa) or factor Xa, these new synthetic agents, given orally, have large therapeutic windows and predictable pharmacokinetics. Their properties allow them to avoid tight monitoring improving patient comfort and security. Pharmacological studies are promising. Regarding some indications, these new drugs seem better than "classical" anticoagulants either in efficacy or in security terms. However, they increase the hemorrhagic risk and particularly in fragile populations like elderly patients or with renal insufficiency. Only few assays are available in the laboratory to evaluate their effects and no antidote is currently on the market. The way to new anticoagulant therapies is now open. In the future, specific indications of vitamin K antagonists, heparins and these new molecules will have to be determined.

Evaluation of the impact of direct plating, broth enrichment, and specimen source on recovery and diversity of methicillin-resistant Staphylococcus aureus isolates among HIV-infected outpatients.

We compared recovery of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) from nasal and groin swab specimens of 600 HIV-infected outpatients by selective and nonselective direct plating and broth enrichment. Swabs were collected at baseline, 6-month, and 12-month visits and cultured by direct plating to mannitol salt agar (MSA) and CHROMagar MRSA (CM) and overnight broth enrichment with subculture to MSA (broth). MRSA isolates were characterized by pulsed-field gel electrophoresis (PFGE), staphylococcal cassette chromosome mec (SCCmec) typing, and PCR for the Panton-Valentine leukocidin. At each visit, 13 to 15% of patients were colonized with MRSA and 30 to 33% were colonized with methicillin-susceptible S. aureus (MSSA). Broth, CM, and MSA detected 95%, 82%, and 76% of MRSA-positive specimens, respectively. MRSA recovery was significantly higher from broth than CM (P ≤ 0.001) or MSA (P ≤ 0.001); there was no significant difference in recovery between MSA and CM. MSSA recovery also increased significantly when using broth than when using MSA (P ≤ 0.001). Among specimens collected from the groin, broth, CM, and MSA detected 88%, 54%, and 49% of the MRSA-positive isolates, respectively. Broth enrichment had a greater impact on recovery of MRSA from the groin than from the nose compared to both CM (P ≤ 0.001) and MSA (P ≤ 0.001). Overall, 19% of MRSA-colonized patients would have been missed with nasal swab specimen culture only. USA500/Iberian and USA300 were the most common MRSA strains recovered, and USA300 was more likely than other strain types to be recovered from the groin than from the nose (P = 0.05).

Methicillin-resistant Staphylococcus aureus colonization in HIV-infected outpatients is common and detection is enhanced by groin culture.

SUMMARYAlthough high rates of clinical infection with methicillin-resistant Staphylococcus aureus (MRSA) have been reported in HIV-infected adults, data on MRSA colonization are limited. We enrolled HIV-infected adults receiving care at the Atlanta VA Medical Center. Swabs from each participant's nares and groin were cultured with broth enrichment for S. aureus. Of 600 HIV-infected adults, 79 (13%) were colonized with MRSA and 180 (30%) with methicillin-susceptible S. aureus. MRSA pulsed-field gel electrophoresis types USA300 (n=44, 54%) and USA500/Iberian (n=29, 35%) predominated. Inclusion of groin swabs increased MRSA detection by 24% and USA300 detection by 38%. In multivariate analysis, MRSA colonization compared to no MRSA colonization was associated with a history of MRSA clinical infection, rarely or never using condoms, and contact with prisons and jails. In summary, the prevalence of MRSA colonization was high in this study of HIV-infected adults and detection of USA300 was enhanced by groin culture.

[Comparative study of five techniques of preparation of platelet-rich plasma]. / Étude comparative de cinq techniques de préparation plaquettaire (platelet-rich plasma).

AIM OF THE STUDY: Injections of platelet-rich plasma (PRP) constitute a new therapeutic for treating chronic tendinopathies. The injection being carried out in the tendon, the volume of PRP should thus be minimal (to decrease the intratendinous pressure and to minimize pain). This PRP should also have a raised platelet count. The quantity of released growth factors could be related to the system of preparation employed. We thus carried out a comparative study of five techniques of preparation of PRP described in the literature. MATERIALS AND METHODS: Samples of venous blood were taken among five patients in order to compare five techniques of preparation of PRP: University Hospital of Liège technique, Curasan(®) PRP Kit, Plateltex(®), GPS(®)II and RegenLab(®). RESULTS: The various techniques make it possible to obtain more important platelet concentration than in blood, with variable volumes (0,3 to 6ml). The number of platelets per microlitre appears higher with Plateltex(®) and obtains smallest volume of PRP. The other techniques also give small volumes except for the GPS(®)II. The number of collected platelets with this technique appears thus higher. The best collect efficiency is obtained with RegenLab(®). CONCLUSION: The technique Plateltex(®) makes it possible to collect the highest concentration of platelets in the smallest volume available.

Comparison of the platelet concentrations obtained in platelet-rich plasma (PRP) between the GPS™ II and GPS™ III systems.

INTRODUCTION: Platelet growth factors are known for their ability to speed up tissue healing (bone, skin, tendons, muscle). Various techniques make it possible to collect this platelet-rich plasma or PRP. METHODS: This study compares the platelet concentrations obtained from five patients using GPS™ III, which has recently come onto the market, with those obtained using GPS™ II. RESULTS AND CONCLUSION: We obtain a platelet concentration that is six to nine times greater with GPS ™ II and GPS™ III, but there is no significant difference between the concentrations of PRP obtained with the two systems.

Surgical resection of a sphenoid wing meningioma in a patient with Glanzmann thrombasthenia.

Glanzmann thrombasthenia (GT) is a rare autosomal recessive disorder characterized by a deficiency or functional defect of platelet glycoprotein (GP) IIb/IIIa. Physiologically, this platelet receptor mediates aggregation of activated platelets by binding the adhesive proteins, fibrinogen, von Willebrand factor (VWF) and fibronectin. This facilitates attachment and aggregation of platelets at sites of vascular injury. We reported the management of a pterional meningioma resection in a patient with Glanzmann thrombasthenia, with recombinant factor VIIa (rFVIIa - NovoSeven) as haemostatic agent. A 48-year-old woman suffering from Glanzmann thrombasthenia was scheduled for spheno-orbital meningioma en plaque surgery. Because of repeated platelet transfusions, this patient developed isoantibodies against missing GPIIbIIIa and alloantibodies against Human Leukocyte Antigen (HLA) leading to refractoriness to platelet transfusions. We observed that Novoseven offered sufficient haemostasis conditions. Therefore, we noticed a deep vein thrombosis. This imposed us to use low weight molecular heparin despite recent surgery.