Three children had factor XI
deficiency (concentrations <34%), and 1 had von Willebrand disease (RCF <29% and vWF antigen <35%).
High levels of Factor XI
increase the risk of thrombosis, a process involving aberrant blood clot formation that can be responsible for heart attacks and strokes, while Factor XI
deficiency results in a lower incidence of thromboembolic events with minimal increase in bleeding risk.
Though thrombotic events have been commonly reported with factor XI
and factor VIII concentrates, it is an unusual complication after administration of DDAVP alone in a patient with VWD.
AF253319), choriogenin 2 (E = 1e-45), choriogenin 3 (E = 4e-43), coagulation factor XI
(E = 3e-12), ER[alpha] (E = 1e-71), glycosylate reductase (E = 3e-14), hepatic lipase precursor (E = 7e-6), 3-hydroxy-3-methylglutaryl-coenzyme A (CoA) reductase (E = 9e-51), low-molecular-mass protein 2 (E = 2e-12), transferrin (E = 8e-26), ubiquitin-conjugating enzyme 9 (the cDNA clone is 87% identical at the 5' end to an EST clone (GenBank accession no.
Genetic polymorphisms with either a positive or negative association with thrombosis and arterial vascular disease have been found in many of the procoagulant proteins, including factor V, prothrombin, fibrinogen, factor VII, factor XI
, and factor XIII (Figure 3).
Most patients with congenital factor XI
deficiency do not have any significant bleeding problems, although there are cases where such patients had significant hemorrhage after surgery or trauma.
One of them, factor XI
, contributes to the formation of the enzyme thrombin, which in turn helps make a protein called fibrin, a key clotting agent in the blood.
can be used in the quantification of Factor VI, Factor VII, Factor VII, Factor IX, and Factor XI
Our testing revealed, however, that only the 1:10 dilution (1 volume of sample in 9 volumes of diluent) revealed a low factor XI
activity, and the factor XI
activity increased with dilution, such that a 1:40 dilution (1 volume sample in 39 volumes diluent) had normal factor XI