Will elevated levels of plasminogen interfere with the Chromogenix Coamatic® Plasmin Inhibitor test?

No, elevated plasminogen levels should not effect the results. Residual plasmin hydrolyzes the chromogenic substrate, but the principle of plasminogen is different. No part is played by plasmin. Instead, determination by chromogenic substrate requires all plasminogen in the sample to be activated to plasminogen/streptokinase complex, which hydrolyzes the chromogenic substrate.

Is there any influence from alpha2-macroglobulin? If so, how can it be overcome?

Coamatic® Plasmin Inhibitor (discontinued) is not influenced by alpha2-macroglobulin up to 9 mmol/l, which is approximately three times higher than the normal level in human plasma.

If a patient plasma is hemolytic or lipemic, how should I analyze it?

Run a blank and subtract it from your sample values. The sample blank activity is determined following the method procedure by substituting the plasmin working solution with a mixture containing 1 volume of plasmin solvent and 1.5 volumes of working buffer.

What clinical situations are associated with decreased levels of plasmin inhibitor? Elevated levels?

Congenital deficiencies are characterized by bleeding occurring some hours after the initial injury. Clotting and wound healing are usually normal, but the hemostatic plug is defective and breaks down prematurely. As a result of liver diseases and DIC, decreased levels of plasmin inhibitor can be observed. Increased levels of plasmin inhibitor have been reported during post-operative episodes.

Describe the measurement principle behind the discontinued Chromogenix Coamatic® Plasmin Inhibitor kit.

Incubation of diluted plasma with an excess of plasmin results in a rapid complex formation between functional plasmin inhibitor present in the plasma and plasmin. The inhibited plasmin activity is proportional to the amount of plasmin inhibitor. The remaining amount of plasmin hydrolyzes the chromogenic substrate S-2403™, thus liberating the chromophoric group pNA.

What is alpha2-antiplasmin (plasmin inhibitor)?

alpha2-antiplasmin is a synonym for plasmin inhibitor, which, as the name implies, is a fast-acting inhibitor of the fibrinolytic system. Plasmin Inhibitor binds with plasmin, forming a stable complex devoid of proteolytic activity. Plasmin inhibitor can also form a reversible complex with the lysine-binding sites of plasminogen, as can histidine-rich glycoprotein (HRG), which has an inhibitory effect on the binding of plasminogen to fibrin.

Protein concentrations in plasma


Weight kDa



Fibrinogen 330 3000 9
Prothrombin 72 150 2
Factor V 330 20 0.05
Factor VII 50 0.5 0.01
Factor VIII 330 0.1 0.0003
Factor IX 56 5 0.09
Factor X 59 8 0.13
Factor XI 160 5 0.03
Factor XII 80 30 0.4
Factor XIII 320 10 0.03
Protein C 62 4 0.06
Protein S 70 10 (free) 0.14
Protein Z 62 2 0.03
Prekallikrein 86 50 0.6
HMW kininogen 120 70 0.6
Fibronectin 450 300 0.7
Plasminogen 92 200 2
t-PA 60 0.005 0.0001
Urokinase 53 0.004 0.0001
Antithrombin 58 145 2.5
Heparin Cofactor II 66 80 1.2
Plasmin Inhibitor 63 60 1
Protein C Inhibitor 57 4 0.07
α2-Macroglobulin 725 2000 3