Acquired hemophilia A (AHA) is a rare hemorrhagic disease in which autoantibodies against coagulation factor VIII- (FVIII-) neutralizing antibodies (inhibitors) impair the intrinsic coagulation system. As the inhibitors developed in AHA are autoantibodies, the disease may have an autoimmune cause and is often associated with autoimmune disease. Although acute hemorrhage associated with AHA may ...

Anticoagulants are pivotal agents for prevention and treatment of thromboembolic disorders. Limitations of existing anticoagulants, vitamin K antagonist and heparins, have led to the development of newer anticoagulant therapies. These anticoagulants have been designed to target specific coagulation enzymes or steps in the coagulation pathway. New anticoagulants that are under evaluation in clin...

Blood coagulation is a complex biological mechanism aimed to avoid bleeding in which a highly regulated and coordinated interplay of specific proteins and cellular components respond quickly to a vascular injury. However, when this mechanisms occurs in the coronary circulation, it has not a "protective" effect, but rather, it plays a pivotal role in determining acute coronary syndromes. Coagula...

In an article in this issue of the Arteriosclerosis, Thrombosis, and Vascular Biology,1 Butenas and colleagues report studies looking at pharmacologic levels of factor VIIa in a model system of hemophilia. Understanding the mechanism by which high-dose factor VIIa increases thrombin generation and enhances hemostasis is important because it is currently being used very effectively in treatment ...

Hemostasis encompasses the tightly regulated processes of blood clotting, platelet activation, and vascular repair. After wounding, the hemostatic system engages a plethora of vascular and extravascular receptors that act in concert with blood components to seal off the damage inflicted to the vasculature and the surrounding tissue. The first important component that contributes to hemostasis i...

Currently, information on hypercoagulability can be achieved directly--through measuring the enzymatic forms of coagulation zymogens generated during coagulation activation--or indirectly--through measuring the activation peptides generated when zymogens are activated or the enzyme-inhibitor complexes formed by inhibition of the enzymes by their plasmatic inhibitors. On the basis of published r...

INTRODUCTION The etiology of preeclampsia is not fully established. A few studies have shown a relationship between natural coagulation inhibitors and preeclampsia. OBJECTIVES The purpose of this study was to investigate the status of natural coagulation inhibitors and active protein C resistance (APC-R) in preeclampsia. PATIENTS AND METHODS We studied 70 women with preeclampsia recruited c...

Protein C, a newly identified inhibitor of blood coagulation, was measured immunologically in 58 patients with untreated acute leukemias and compared with that of normal subjects. On the average, slightly lower values were found. However, the 17 patients with overt laboratory pictures of decompensated disseminated intravascular coagulation (DIC), including 11 cases with acute promyelocytic leuk...

Fibrin plays an essential role in hemostasis as both the primary product of the coagulation cascade and the ultimate substrate for fibrinolysis. Fibrinolysis efficiency is greatly influenced by clot structure, fibrinogen isoforms and polymorphisms, the rate of thrombin generation, the reactivity of thrombus-associated cells such as platelets, and the overall biochemical environment. Regulation ...

The dose-limiting issue with available anticoagulant therapies is bleeding. Is there an approach that could provide antithrombotic protection with reduced bleeding? One hypothesis is that targeting proteases upstream from the common pathway provides a reduction in thrombin sufficient to impede occlusive thrombosis yet allows enough thrombin generation to support hemostasis. The impairment of in...