Major Bleeding Tendency Research Articles

Complex management of type 2 heparin-induced thrombocytopenia in patients with major bleeding tendency: two case report

Type 2 heparin-induced thrombocytopenia (HIT 2) is a rare pro-thrombotic disorder occurring in patients treated with heparin. It is defined as a clinical-biological syndrome associating the sudden onset of a thrombocytopenia, characterized by a drop of more than 50% of the initial platelet count, and thrombosis. We report two cases of HIT 2 occurring in patients with major bleeding tendency. The first HIT occurred in a patient whose management, in accordance with current guidelines, made it possible to control the thrombocytopenia and the anticoagulation despite the complexity of adapting and monitoring treatments in the context of recent cerebral hemorrhage. The second refers to an autoimmune HIT, which occurred in a patient whose management required the use of alternative therapies to the standard treatments suggested for HIT 2, to correct the severe refractory thrombocytopenia.

Mild Bleeders: Diagnosis is Elusive in Large Number of Patients.

BackgroundBleeding is a common clinical presentation. Even patients with mild bleeding disorders are extensively investigated for ascertaining the cause. The present study was conducted in order to evaluate the extent of the possibility of diagnosis in mild bleeding disorders.Material and MethodsThis was a prospective study of patients referred for work up of mild bleeding for a period of 13 months. A complete blood count, peripheral smear examination, Prothrombin time, Partial Thromboplastin time and Thrombin Time, Platelet Aggregometry test, tests for von Willebrand’s disease and Platelet Factor 3 availability were measured.Results164 patients presented with mild bleeding, in 114 of the patients a single site of bleeding was present. Epistaxis was the most common presentation (39%). Cutaneous bleeding (petechiae and purpura) was the next common site. History of a major bleeding tendency in the family was present only in 11 patients. The investigations showed that VWD (17/164), followed by clotting disorders (CD) mainly mild hemophilia (15/164) were the most common diagnosable cause. There were also 4 cases of hypofibrinogenemia. The disorders of platelets (Platelet function defects/PFD) were the least common (9/164). Rest 123 (75%) patients could not be diagnosed on the basis of these investigations and were labeled as Bleeding disorders – Unclassified (BDC).Conclusionn our study, 75% of the patients with mild bleeding remained undiagnosed even after extensive laboratory workup, thus raising a very pertinent question that is it necessary that all mild bleeders submit to a broad battery of investigations, as the diagnosis continues to be elusive despite extensive workup.

Ex vivo inhibition of thrombus formation by an anti-glycoprotein VI Fab fragment in non-human primates without modification of glycoprotein VI expression.

Glycoprotein (GP)VI is an attractive target for the development of new antithrombotic drugs. Its deficiency protects animals in several models of thrombosis, arterial stenosis and ischemia--reperfusion while inducing no major bleeding tendency. The Fab fragment of one anti-GPVI monoclonal antibody (9O12.2) inhibits all GPVI functions in vitro. The aim of this study was to determine the ex vivo effects of 9O12.2 Fab on hemostasis, coagulation and thrombosis in non-human primates. Blood samples were collected from cynomolgus monkeys before and after (30, 90 and 150 min, 1 and 7 days) a bolus injection of 9O12.2 Fab (4 mg kg(-1)) or vehicle. Platelet counts and coagulation tests (prothrombin time, activated partial thromboplastin time) were not modified following Fab injection. The PFA-100 closure time increased during the first hours and returned to initial values on day + 1. Platelet-bound Fab was detected from 30 min to 24 h after Fab injection without GPVI depletion at any time. Collagen-induced platelet aggregation was selectively and fully inhibited at 30 min. Thrombus formation on collagen in flowing whole blood (1500 s(-1)) was delayed and decreased, and collagen-induced or tissue factor-induced thrombin generation in platelet-rich plasma was profoundly inhibited. The anti-GPVI 9O12.2 Fab inhibits thrombus formation ex vivo in non-human primates with a composite effect on platelet activation and thrombin generation in the absence of GPVI depletion.

Severe factor X deficiency due to a homozygous mutation (Cys364Arg) that disrupts a disulphide bond in the catalytic domain

Severe factor X deficiency (<0.01 IU mL(-1)) is a rare disorder producing a major bleeding tendency including umbilical cord, joint and intracranial haemorrhage. We present the first case of a child homozygous for a g.1177T > C missense alteration, predicted to disrupt the catalytic domain, and resulting in severe FX deficiency. The child suffered intracranial haemorrhage and now receives regular prophylaxis with a prothrombin complex concentrate. Our experience and a review of the literature suggest that optimal frequency of dosing is likely to be two or three times weekly and that the risk of thrombosis is very small.