No impact of factor IX Ala-10 mutations in acenocoumarol-treated southern Europeans.

Increased risk of bleeding during oral anticoagulant (OA) treatment may be related to mutations in the precursor of coagulation factor IX. Missense mutations at Ala-10 (Ala-10Thre and Ala-10Val) in the factor IX propeptide lead to impaired carboxylation of factor IX. When patients carrying these mutations are treated with coumarins, functional factor IX levels decrease significantly, leading to an excessively prolonged activated partial thromboplastin time (aPTT) and an increased bleeding risk.

Effects of beta2-glycoprotein I and monoclonal anticardiolipin antibodies in platelet interaction with subendothelium under flow conditions.

Objective: To evaluate whether the effect of human monoclonal anticardiolipin antibodies (aCL) on platelet interaction with the subendothelium under flow conditions is dependent on beta(2)-glycoprotein I (beta(2)GPI).

Methods: Three monoclonal IgM aCL with anti-beta(2)GPI activity (TM1B3, GR1D5, and EY2C9) obtained from patients with antiphospholipid syndrome, a monoclonal aCL with lupus anticoagulant activity but without anti-beta(2)GPI activity (FRO) obtained from a patient with a splenic lymphoma, and a control monoclonal IgM without aCL activity were used. TM1B3, GR1D5, EY2C9, FRO, and control IgM (30 microg/ml) were added to reconstituted blood containing gel-filtered platelets (200 x 10(9)/liter), factor VIII (100 units/dl), and fibrinogen (1.

Pharmacogenetics of acenocoumarol: cytochrome P450 CYP2C9 polymorphisms influence dose requirements and stability of anticoagulation.

Background And Objectives: Cytochrome P4502C9 (CYP2C9) is the main enzyme implicated in coumarinic metabolism. Variant alleles, CYP2C9*2 and CYP2C9*3, have been related to decreased enzymatic activity, but their clinical relevance in acenocoumarol metabolism has not been established. We investigated CYP2C9 polymorphisms in relation to acenocoumarol dose requirement, stability of anticoagulation and bleeding.

Vascular involvement in Behçet's disease: relation with thrombophilic factors, coagulation activation, and thrombomodulin.

Purpose: Thrombosis, usually venous, occurs in 10% to 25% of patients with Behçet's disease, but its pathogenesis is poorly understood. We evaluated parameters of hemostasis and their relation with thrombosis in a series of patients with Behçet's disease.

Subjects And Methods: We studied 38 patients with Behçet's disease (13 with venous thrombosis), 38 patients with venous thrombosis without thrombophilia, and 100 control subjects.