Factor XIII( fibrin-stabilizing factor)
The reference value of the activity of factor XIII in blood plasma is 100%.
Factor XIII( fibrin-stabilizing factor, fibrinase) refers to P2-glycoproteins. It is present in the vascular wall, platelets, erythrocytes, kidneys, lungs, muscles, placenta. In plasma it is in the form of a proenzyme, connected with fibrinogen.
Factor XIII under the influence of thrombin is converted to the active form of XIIIa, which during the formation of the fibrin clot ensures the formation of cross-linked forms of fibrin. Thrombi formed in the presence of fibrinase are very slowly lysed. With a decrease in the activity of factor XIII, the clots decay very quickly, even if the fibrinolytic activity of the blood is normal. If the wall of the blood vessel is damaged, factor XIII is involved in the process of aggregation and adhesion of blood platelets. It has been established that a decrease in fibrinase activity is accompanied by a decrease in adhesiveness and aggregation of platelets, and when the activity of fibrinase increases, these properties of platelets, on the contrary, increase.
Factor XIII characterizes the III phase of blood coagulation: a decrease or increase in fibrinase activity is considered as a factor of hemorrhagic or thrombotic risk.
Congenital deficiency of factor XIII is inherited by autosomal recessive type predominantly in men. The first clinical sign of fibrinase deficiency in 80% of patients is a prolonged( during
days, sometimes weeks) bleeding from the umbilical wound. The bleeding of the petechial type is characteristic. Possible hemorrhages in the brain. The slow healing of wounds is noted, post-operative hernia is often formed, fractures are poorly coalesced. All parameters in the coagulogram, in addition to reducing the concentration of factor XIII in the blood plasma, remain within normal limits. Acquired deficiency of factor XIII is found in patients with avitaminosis C, radiation sickness, leukemia, cirrhosis, hepatitis, cancer with metastases to the liver, lymphoma, with DIC syndromes, in adrenalectomies who have transferred, after taking anticoagulants of indirect action. Reduction of the factor of HS in the blood in these diseases is due to a violation of its synthesis or expenditure in the process of DIC syndrome.
For prolonged and poorly healing wounds and fractures, it is recommended to carry out a study of the activity of factor XIII, since in some cases such phenomena can be associated with its deficiency( X-factor stimulates the development of fibroblasts).
The minimum hemostatic level of activity of factor XH in the blood to stop bleeding is 1-2%, with a lower content of bleeding stopping without the administration of a factor of HSH is impossible [Ogston D., Bennett B., 1977].
In patients with thromboembolic complications, atherosclerosis, after surgery, childbirth, after administration of epinephrine, HA, pituitrin, the activity of fibrinase is often increased.