Baseline and treatment-related changes in thrombin generation in patients with multiple myeloma.

The prothrombotic risk in multiple myeloma (MM) could be potentially assessed by thrombin generation (TG) assays. TG was performed using Calibrated Automated Thrombography with 5 and 1 pM tissue factor. We compared baseline TG among 24 MM patients, 19 MGUS, and 50 healthy controls, and assessed change in TG in MM patients during the initial treatment period at 1, 2, and 3 months.

Evaluation of pre-analytical variables in a commercial thrombin generation assay.

Background: There is minimal data on the influence of pre-analytical variables on the use of calibrated automated thrombography (CAT), to measure thrombin generation.

Objectives: To evaluate the impact of centrifugation methods, time after collection, and contact activation inhibition on the CAT assay performed using two commercial reagents.

Methods And Results: Six different methods of plasma separation were examined.

Diagnostic testing for mild hemophilia a in patients with discrepant one-stage, two-stage, and chromogenic factor VIII:C assays.

In recent years, there has been greater awareness among hemostasis scientists and clinicians that factor VIII coagulant activity (FVIII:C) measured in certain patients with mild hemophilia A can show different results depending on the assay system. A subgroup of mild hemophilia families have a method-related discrepancy in FVIII:C results, whereby the one-stage clotting assay (FVIII:C-1) is significantly higher than the two-stage clotting assay (FVIII:C-2) or the chromogenic assay (FVIII:C-chr). To identify such patients, the routine laboratory can use automated procedures for the FVIII:C-chr to replace the complex, manual FVIII:C-2 method.

Diagnosis and management of adult patients with von Willebrand disease in South Australia.

We have analyzed the databases for von Willebrand disease (VWD) from the hemophilia center for adult patients with bleeding disorders in South Australia. We define the prevalence of types of VWD to determine the proportion of who would be treated with factor (F) VIII/von Willebrand factor (VWF) concentrate to prevent or control hemorrhage. In severe or moderately severe patients, we use plasma-derived FVIII/VWF concentrate, and for mild to severe cases, we use desmopressin plus tranexamic acid.

Latest medical treatment strategies for venous thromboembolism.

Anticoagulant therapy with unfractionated heparin (UFH) followed by warfarin prevents thrombus extension, reduces the risk of recurrent thrombosis and prevents death in patients with venous thromboembolism (VTE). Low-molecular-weight heparin (LMWH) has replaced UFH as the preferred initial anticoagulant therapy for VTE because it is as effective and safe as UFH, but does not require laboratory monitoring and is less likely to cause immune thrombocytopenia and osteoporosis. More recently, fondaparinux has been shown to be an effective and safe alternative to LMWH and several new parenteral anticoagulants are being evaluated.

In the presence of phospholipids, glycosaminoglycans potentiate factor Xa-mediated protein C activation by modulating factor Xa activity.

Although the thrombin/thrombomodulin complex is considered the physiological activator of protein C, factor Xa (f.Xa) can also activate protein C in a reaction that is potentiated by glycosaminoglycans. To explore this phenomenon, we first examined the effect of glycosaminoglycans of varying degrees of sulfation on the kinetics of protein C activation by f.

New anticoagulants for the prevention and treatment of venous thromboembolism.

Anticoagulant therapy is effective at preventing the development of venous thromboembolism in high-risk patients, and reduces morbidity and mortality in individuals with established thromboembolic disease. Vitamin K antagonists and heparins are currently the most commonly used anticoagulant drugs, but they have practical limitations. Therefore, new antithrombotic agents with predictable dose-responses (thereby decreasing the need for monitoring without compromising efficacy or safety), ideally available in an oral formulation and with a rapidly reversible anticoagulant effect, are needed.

Update in the diagnosis of deep-vein thrombosis and pulmonary embolism.

Purpose Of Review: Diagnostic strategies for venous thromboembolism must both accurately diagnose thrombus when present, and safely exclude it when absent. This review summarizes recent data on diagnostic strategies for venous thromboembolism.

Recent Findings: Noninvasive diagnostic strategies have emerged to limit the need for invasive testing for deep-vein thrombosis and pulmonary embolism.

New anticoagulants for venous thromboembolic disease.

Purpose Of Review: In this paper, recent advances in new anticoagulants with the potential to be used for prevention or treatment of venous thrombosis are reviewed.

Recent Findings: Numerous novel anticoagulants targeting specific stages of the coagulant pathway are in various stages of development. Fondaparinux, an indirect activated factor VII inhibitor, has been shown to be effective for initial treatment and prevention of venous thromboembolism, but still requires parenteral administration.

The diagnostic evaluation of pulmonary embolism.

Due to the morbidity and mortality associated with either untreated disease or inappropriate anticoagulant therapy, accurate diagnosis of pulmonary embolism is essential. Pulmonary angiography, the current gold standard test for diagnosing pulmonary embolus, is both invasive and costly; therefore, noninvasive diagnostic strategies have been developed. Noninvasive tests often have to be combined to either raise the posttest probability of disease to a level justifying treatment or lower it to a level at which withholding treatment is warranted.

The diagnostic evaluation of deep vein thrombosis.

Due to the morbidity and mortality associated with either untreated disease or inappropriate anticoagulant therapy, accurate diagnosis of venous thromboembolism is essential. As venography, the current gold standard test for deep vein thrombosis (DVT), is both invasive and costly, noninvasive diagnostic strategies for diagnosing DVT have been developed. Noninvasive tests often have to be combined to either raise the post-test probability of disease to a level justifying treatment or lower it to a level at which withholding treatment is warranted.

Initial treatment of venous thromboembolism.

Adequate initial anticoagulant therapy of deep venous thrombosis (DVT) is required to prevent thrombus growth and pulmonary embolism (PE). Intravenous unfractionated heparin (UFH) is being replaced by low-molecular-weight heparin (LMWH) as the anticoagulant of choice for initial treatment of venous thromboembolism (VTE). Both agents are relatively safe and effective when used to treat VTE, with LMWH suitable for outpatient therapy because of improved bioavailability and more predictable anticoagulant response.