Determination of Plasma Prothrombin Level by Ca2+-Dependent Prothrombin Activator (CA-1) during Warfarin Anticoagulation
Hidehiko Iwahashi MD, Michio Kimura MD, Kyoko Nakajima PhD, Daisuke Yamada PhD, Takashi Morita PhD

Prothrombin levels were measured using the prothrombin activator, carinactivase-1 (CA-1), the data obtained with the CA-1 test being comparable with those provided by the prothrombin time (PT) and Thrombotest (TT). The CA-1 test provides quantitative analysis, while the PT and TT provide qualitative analysis. Thus, the CA-1 test is valuable in monitoring warfarin anticoagulation therapy.