clotting factors

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Clotting factors

Substances in the blood that act in sequence to stop bleeding by forming a clot.

coagulation factors

; clotting factors approximately 20 soluble plasma factors, including fibrinogen (factor [F] I), prothrombin (FII), thromboplastin (FIII) and calcium ions (FIV), which on activation initiate a biochemical cascade that converts soluble plasma fibrinogen into insoluble fibrin (into which platelets enmesh, forming a clot); factor deficiency (e.g. FVIII; FXII) causes bleeding disorders (haemophilia; Christmas disease and von Willebrand's disease)

clotting factors, the chemical and cellular constituents of the blood responsible for the conversion of fibrinogen into a mesh of insoluble fibrin causing the blood to coagulate or clot.


the formation of a jellylike substance over the ends or within the walls of a blood vessel, with resultant stoppage of the blood flow. Clotting is one of the natural defense mechanisms of the body when injury occurs. A clot will usually form within 5 minutes after a blood vessel wall has been damaged. The clotting mechanism is triggered by the platelets, which disintegrate as they pass over rough places in the injured surface. As they disintegrate they release serotonin and thromboplastin. Serotonin causes constriction of the blood vessels and reduction of local blood pressure. Thromboplastin unites with calcium ions and other substances which promote the formation of fibrin. When examined under a microscope, a clot consists of a mesh of fine threads of fibrin in which are embedded erythrocytes and leukocytes, small amounts of fluid (serum), and platelets.

clotting defects
clotting factors
a series of plasma proteins which are related through a complex cascade of enzyme-catalyzed reactions involving the sequential cleavage of large protein molecules to produce peptides, each of which converts an inactive zymogen precursor (factor II) into an active enzyme (Iia) leading to the formation of a fibrin clot. They are designated by Roman numerals, and an additional 'a' to indicate the activated state. They are: factor I (fibrinogen), factor II (prothrombin), factor III (tissue thromboplastin), factor IV (calcium), factor V (proaccelerin), factor VI (no longer considered active in hemostasis), factor VII (proconvertin), factor VIII (antihemophilic factor), factor IX (plasma thromboplastin component; Christmas factor), factor X (stuart factor), factor XI (plasma thromboplastin antecedent), factor XII (hageman factor), factor XIII (fibrin stabilizing factor).
clotting time
the time required for blood to clot in a glass tube; a measure of the intrinsic system of coagulation. In the Lee-White method, blood in test tubes is maintained at a constant temperature and examined regularly until clotting occurs; the test can be also be performed in capillary tubes. Called also coagulation time. Less sensitive and now less often used than the activated coagulation time.
tissue clotting factor
clotting factor III; tissue thromboplastin.
References in periodicals archive ?
Biogen Idec and Swedish Orphan Biovitrum applied Fc fusion technology in hemophilia for the first time with the goal of making clotting factors last longer and reduce the burden of injections for patients and their families.
Such women have reduced levels of clotting factors, usually about 50% below normal, regardless of the severity of the hemophilia they carry (Lancet 362[9381]:351-54, 2003).
In addition, the "turbocharged" clotting factor protein eliminated pre-existing antibodies that often weaken conventional treatments for people with hemophilia.
According to the WFH, this donation of blood clotting factor products will secure an average of 40,000 doses to treat approximately 10,000 patients in developing countries worldwide through 2017, where access to adequate treatment is often lacking or absent.
Kcentra helps restore blood coagulation by replenishing the levels of clotting factors that were depleted by warfarin therapy.
However, high triglyceride levels may increase levels of several clotting factors that boost heart attack risk, the panel warned.
As one of the nation's fastest growing providers of hemophilia clotting factors and other specialty pharmaceuticals such as IVIG, the company's clinical staff reaches patients and physicians in 45 states.
CSL Behring, in collaboration with its parent company, CSL Limited (ASX: CSL), is developing rVIIa-FP, a novel therapy to treat hemophilia A and hemophilia B patients who have inhibitors (antibodies that develop in response to treatment with other clotting factors that prevents those treatments from working) as part of the PROLONG 7- FP clinical study program.
In its Pharmaceutical segment, Biotest develops immunoglobulins, clotting factors and albumins based on human blood plasma.
Lifesaving plasma protein therapies include plasma-derived and recombinant blood clotting factors.
Perhaps, some have suggested, AIDS viruses sometimes become noninfectious during normal preparation and storage of clotting factors, even without heat treatment.
Additionally, it is fully bio-absorbable and because it does not rely solely on clotting factors in the patient's blood, it works quickly even on highly anti-coagulated patients.