A New-Generation Method for Quick and Owren PT

Oral anticoagulant therapy (OAT) calls for continuous control by prothrombin time (PT) test, as the therapeutic range in INR units is very narrow. Warfarin (or coumarin) inhibits coagulation factor synthesis in the liver, but at the same time inactive coagulation factors are formed. The aim here was to measure "active coagulation factors" and inhibition in calibrator kits and patient plasmas by a new method for Quick and Owren PT. Four calibration kits and 200 plasma samples obtained from OAT patients were assessed using Quick and Owren PT for INRTot (active coagulation factors + inhibition) and INRAcf (only active coagulation factors). Conspicuous variation in in- hibition was noted between the four calibration kits. The new- generation PT method develops anticoagulation therapy based on active coagulation factors in vivo and improves INR result harmonization for Quick and Owren PT reagents. This new approach improves Quick PT reliability.