Helena Factor XI (10x1mL)

Factor XI (10x1mL)

Factor XI Deficient Substrate, 10 x 1 mL

Intended Use

The Factor XI Deficient Substrate Plasma is intended for the quantitative determination of Factor XI (plasma thromboplastin antecedent) in patients suspected of having a congenital or acquired deficiency of this coagulation protein. 

Summary 

Numerous coagulation factors have been identified in the blood, and are required for normal blood clotting. A deficiency of one or more of the factors may result in a notable hemorrhagic condition, the severity of which is governed by the degree of the deficiency. Deficiencies of the blood clotting factors may be congenital or acquired. The congenital deficiencies are, in general, single deficiency states while the acquired deficiencies may be multiple in nature, and commonly associated with liver disease, vitamin K deficiency or the ingestion of coumarin type anticoagulant drugs, and defibrination secondary to intravascular clotting.

Factor XI, also referred to as plasma thromboplastin antecedent (PTA), activity is decreased in Rosenthal’s disease or hemophilia C. It is an autosomal recessive disease that occurs mainly in individuals of Jewish ancestry. The disease occurs with equal frequency in males and females.In an effort to devise a quantitative assay for Factor XI, several methods based on the thromboplastin test were used and were found to be time consuming and complicated. Langdell, Wagner and Brinkhous (1953) developed a one-stage “partial thromboplastin time” which was simple to perform but not reproducible. Helena’s procedure determines Factor XI activity by using a modification of the activated partial thromboplastin time (APTT) test and a Factor XI deficient substrate plasma.