Comparative Evaluation of the Performance of Different Thromboplastin Reagents on Prothrombin Time in Situations of Isolated Extrinsic Pathway Factor Deficiency or Liver Damage

Primary purpose : Compare the sensitivity of several thromboplastin reagents of various origins to prothrombin time and factor II, V, VII and X assays in two different populations of patients : * Patients with an isolated extrinsic pathway deficiency (acquired or congenital) of factor II or V or VII or X. * Patients with an hepatocellular insufficiency generally associated with coagulopathy (with an intensity proportional to the degree of hepatic impairment). Results of this work should improve knowledge of sensitivity of the screening test represented by the prothrombin time, depending on the origin of thromboplastin reagent used, in relation with coagulopathies mentioned above, as well as the performance of factors II, V, VII, X assays. This work would help to choice of the most suitable reagent for the needs of each hemostasis laboratory/center.