Spontaneous Bleeding (spontaneous + bleeding)

Distribution by Scientific Domains


Selected Abstracts


Mild haemophilia: a disease with many faces and many unexpected pitfalls

HAEMOPHILIA, Issue 2010
K. PEERLINCK
Summary., Despite major advances in diagnosis and treatment, the management of patients with mild haemophilia (MH) remains a major challenge. Mild haemophilia is defined by factor levels between 0.05 and 0.40 IU mL,1. The bleeding associated with mild haemophilia is most frequently episodic, occurring during surgery or following trauma. Spontaneous bleeding is rare. Diagnosis is sometimes delayed because of insensitivity of screening clotting assays or discrepancies in factor VIII activity as measured by different assays. The treatment of choice in mild haemophilia A is desmopressin, which typically induces a 2,6-fold increase of factor VIII over baseline. However, desmopressin has its limitations in this setting such as the occurrence of tachyphylaxis and failure to respond in an undetermined proportion of patients. Factors underlying poor biological response or magnitude of response to desmopressin are incompletely understood. Inhibitor development in mild haemophilia is particularly distressing. This complication arises at an older age in this patient group because of infrequent need for factor VIII replacement. Inhibitors in mild haemophilia patients often cross-react with endogenous factor VIII resulting in severe spontaneous bleeding frequently in a postoperative setting. Intensive perioperative use of factor VIII and some specific mutations induce a particularly high risk for inhibitor development, but risk factors are incompletely understood. For reasons of the older age of the patients, treatment of bleeding with bypassing agents may cause major thrombotic complications. Data on therapeutic options for inhibitor eradication in patients with mild haemophilia are particularly scarce. With increased life-expectancy for all haemophilia patients, the group of elderly patients with mild haemophilia requiring major surgery will further increase. Prevention of inhibitors, particularly in this patient group, should be a major topic of interest in both clinic and research. [source]


Applicability and safety of recombinant activated factor VII to control non-haemophilic haemorrhage: investigational experience in 265 children

HAEMOPHILIA, Issue 4 2008
M. HERBERTSON
Summary., Experience of recombinant activated factor VII (rFVIIa, NovoSeven®; Novo Nordisk A/S, Bagsvaerd, Denmark) to control haemorrhage in non-haemophilic children is limited. The object of this study was to examine the applicability and safety of rFVIIa amongst a group of non-haemophilic paediatric subjects. Details of all non-haemophilic children ,16 years receiving rFVIIa whose data were recorded in the investigational, internet-based registry, haemostasis.com were analysed. A total of 265 children (mean age 7.7 years) were treated with rFVIIa; the median dose administered was 78.4 ,g kg,1 body weight (range 9.0,393.4) and the median total dose received 100.0 ,g kg,1 body weight (range 10.9,1341.2). Therapeutic areas included surgery (34.5%), coagulopathy (including thrombocytopenia; 29.0%), spontaneous bleeding (17.2%), trauma (8.4%) and intracranial haemorrhage (4.5%). Two patients experienced thromboembolic events following administration of rFVIIa. Thirty-nine patients died on account of haemorrhage or complications relating to their underlying condition; neither the thromboembolic events nor the deaths were related to rFVIIa administration. Bleeding stopped in 118/237 (49.8%), markedly decreased in 54/237 (22.8%), decreased in 51/237 (21.5%), remained unchanged in 13/237 (5.5%) and increased in 1/237 (0.4%) patients. These results suggest that rFVIIa is safe and widely applicable in children to control non-haemophilic haemorrhage. [source]


Bruising: When it is spontaneous and not idiopathic thrombocytopenia purpura

JOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 4 2007
Amanda L Davey
Abstract: Bruising is a presentation that often causes concern. There are many causes of bruising in children, including non-accidental injury, which must be excluded. We report a case of a 22-month-old boy where all the common diagnoses were excluded. We highlight the need to be aware of transient acquired inhibitors of coagulation that can cause spontaneous bleeding. [source]


What is vinculin needed for in platelets?

JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 10 2010
J. V. MITSIOS
Summary.,Background: Vinculin links integrins to the cell cytoskeleton by virtue of its binding to proteins such as talin and F-actin. It has been implicated in the transmission of mechanical forces from the extracellular matrix to the cytoskeleton of migrating cells. Vinculin's function in platelets is unknown. Objective: To determine whether vinculin is required for the functions of platelets and their major integrin, ,IIb,3. Methods: The murine vinculin gene (Vcl) was deleted in the megakaryocyte/platelet lineage by breeding Vcl fl/fl mice with Pf4,Cre mice. Platelet and integrin functions were studied in vivo and ex vivo. Results: Vinculin was undetectable in platelets from Vcl fl/fl Cre+ mice, as determined by immunoblotting and fluorescence microscopy. Vinculin-deficient megakaryocytes exhibited increased membrane tethers in response to mechanical pulling on ,IIb,3 with laser tweezers, suggesting that vinculin helps to maintain membrane cytoskeleton integrity. Surprisingly, vinculin-deficient platelets displayed normal agonist-induced fibrinogen binding to ,IIb,3, aggregation, spreading, actin polymerization/organization, clot retraction and the ability to form a procoagulant surface. Furthermore, vinculin-deficient platelets adhered to immobilized fibrinogen or collagen normally, under both static and flow conditions. Tail bleeding times were prolonged in 59% of vinculin-deficient mice. However, these mice exhibited no spontaneous bleeding and they formed occlusive platelet thrombi comparable to those in wild-type littermates in response to carotid artery injury with FeCl3. Conclusion: Despite promoting membrane cytoskeleton integrity when mechanical force is applied to ,IIb,3, vinculin is not required for the traditional functions of ,IIb,3 or the platelet actin cytoskeleton. [source]