Procedure for the standardization of coagulation tests
View Patent ↗The present invention lies in the field of coagulation diagnosis and relates to a procedure for the standardization of coagulation tests, where calibrators are used to which a discrete standard coagulation time is assigned. The procedure is particularly suitable for the standardization of prothrombin time, activated partial thromboplastin time, thrombin time, ecarin time or batroxobin time.
1. A method for the determination of a standardized coagulation time of a sample, comprising
a) measuring the coagulation time of a sample in a test system:
b) measuring the coagulation times of at least two calibrators, for which discrete standard coagulation times have been predetermined, in the same test system as used in step a);
c) forming a calibration curve that plots the predetermined standard coagulation times of the calibrators versus the coagulation times of the calibrators measured in step b); and
d) converting the coagulation time of the sample measured in step a) to a standardized coagulation time using the calibration curve formed in step c).
2. The method as claimed in claim 1 for the determination of a standardized coagulation time wherein the coagulation time is chosen from prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (U), batroxobin time (BT) and ecarin time (ECT).
3. The method as claimed in claim 1 , wherein the sample is a plasma sample.
4. The method as claimed in claim 1 , wherein the calibrators are plasma-based.
5. The method as claimed in claim 1 , wherein the calibrators are plasma pool-based.
6. The method as claimed in claim 1 , wherein the sample contains a substance which influences the coagulability of the sample.
7. The method as claimed in claim 6 , wherein the substance which influences the coagulability of the sample is an anticoagulatory substance.
8. The method as claimed in claim 7 , wherein the anticoagulatory substance is chosen from heparin, heparinoids, hirudin, argatroban, melagatran and natural or synthetic factor Xa inhibitors.
9. The method as claimed in claim 7 , wherein at least one calibrator contains a defined amount of an anticoagulatory substance.
10. The method as claimed in claim 9 , wherein the anticoagulatory substance contained by at least one calibrator is heparin at a concentration of 0.1 to 1.0 IU per ml.
11. The method as claimed in claim 1 , wherein the calibration curve is plotted with the aid of an interpolation or extrapolation procedure.