Thrombogenic Characteristics of Activated and Standard Concentrates of Prothrombin Complex

The composition of a variety of prothrombin complex concentrates(PCs), including an “activated” product, was examined to determine thrombogenic potential. Small amounts of Xa activity were found to be presentin all products surveyed, although much greater quantities were present in the activated one. Valuesfor prothrombin factors VII, IX, and X activity varied over a limited range, from one productto another, and small quantities of factors XI and XII were identified in several concentrates. Animal recipients of each product, receiving a dose of 100 u/kg developed intravascular coagulation. Prior incubation of the products with Antithrombin III to eliminate activated factors did not alter the coagulopathy pattern.

It was concluded that the presence of factor Xa was not responsible for the observed intravascular coagulation syndrome, and that other factors, such as increased procoagulant levels in the circulation, or the presence of other prothrombin intermediates must be involved.