Plasma thrombin time
The plasma thrombin time (PTZ) or thrombin time (TZ) measures the conversion of fibrinogen to fibrin after adding a test solution of thrombin (factor IIa) to citrate plasma . This test is used to find a fibrinogenfailure to diagnose, e.g. B. in a fibrinolysis therapy with streptokinase .
The test result (in seconds) and the respective normal range are strongly dependent on the thrombin used , but in Germany they are often given between 20 and 38 seconds.
By adding thrombin, the last step ("common end section") of the plasmatic coagulation cascade - the conversion of fibrinogen into fibrin - is tested, regardless of the previous steps that lead to the formation of thrombin (factor IIa) from prothrombin (factor II) to lead.
The plasma thrombin time should not be confused with the very similarly named and abbreviated thromboplastin time (TPZ, English PT - nowadays practically only used as a starting value for the determination of Quick or INR): In the latter, the extrinsic path of plasmatic coagulation is achieved by adding tissue thromboplastin tested as a whole.
