The causes of disturbance in the plasmin system

Under the influence of various pathological processes, the state of the plasmin system and the production of its individual components change. As a result of the activation of the plasmin system, hemostasis is disrupted and hemorrhagic fibrinolytic syndrome often develops. Clinically, it is manifested by severe bleeding due to multiple defects in the hemostatic system. This syndrome can be latent: bleeding is noted in patients only in the postoperative and postpartum periods with tissue damage. Most often, such conditions are revealed in patients with liver damage as a result of a decrease in the synthesis of antiplasms, in the defeat of organs rich in plasminogen activators, and in operative interventions on them (for prostate and lung cancer surgery), less often in patients with increased production (drug, bacterial, stress, etc.) activators of plasminogen or their increased concentration. This fibrinolysis, caused by the primary activation of the plasmin system as such and does not reflect the body's response to increased fibrin formation, is the primary fibrinolysis. For its correction, antifibrinolytic preparations such as antiproteases (aprotinin, ε-aminocaproic acid) are prescribed.

In most cases, secondary fibrinolysis is observed due to the activation of the plasmin system for fibrin formation in the body. In secondary fibrinolysis, plasmin activity first increases, and then gradually decreases and, finally, completely disappears due to depletion of plasminogen stores. The concentration and activators of plasminogen are often reduced against the background of a reduced or increased amount of antiplasms. The ability of a number of drugs to convert inactive plasminogen to plasmin is the basis for thrombolytic therapy in patients with myocardial infarction and thromboembolism - by administering plasminogen activators (most commonly streptokinase preparations). When carrying out thrombolytic therapy, constant monitoring of the level of plasminogen in the blood is necessary.

Changes in the system of hemostasis in primary and secondary fibrinolysis

Indicators	Fibrinolysis
	Primary	Secondary
Fibrinogen	Decreased	Decreased
Plasminogen	Enhanced	Decreased
α 2 -an	Decreased	Enhanced
PDF	Enhanced	Enhanced

The most pronounced shifts in the plasmin system are traced in the DIC syndrome, when the activation of fibrinolysis initially is a protective, sanogenic reaction, and therefore plasmin inhibitors are contraindicated here.

It should be borne in mind that plasminogen, as well as all other proteins of the acute phase, increases with infections, injuries, tumors and in recent months of pregnancy.