Patent ID: 7767459

Claim:
A method for determining protein induced by vitamin K absence or antagonists (Pivka)-corrected prothrombin time (PT) comprising the steps of: a) measuring prothrombin time of at least two different dilutions of a plasma or whole blood sample taken from a patient under oral anticoagulant therapy (OAT) or a patient with hepatocellular carcinoma (HCC) or of a calibrator or control plasma sample in order to determine t min or INR min value for the sample, t min being a y-intecerpt of a plot of clotting time versus dilution factor and INR min being a y-intercept of a plot of clotting time (t) versus international normalised ratio (INR), the sample including Pivka; b) measuring prothrombin time of at least two different dilutions of Pivka-free plasma or whole blood sample in order to determine t min or INR min value for the Pivka-free plasma or whole blood; c) calculating t Pivka or INR Pivka value from the results of the steps a) and b), t Pivka being the effect of Pivka on clotting time calculated by subtracting t min for the Pivka-free plasma or whole blood from the t min value for the sample in step a) and INR Pivka being the effect of Pivka on INT calculated by subtracting INR min for the Pivka-free plasma or whole blood from the INR min value for the sample in step a); and d) determining the Pivka corrected PT for the sample of step a) by subtracting the t Pivka or INR Pivka value obtained in step c) from a prothrombin time measured in step a).