An immunological investigation of factor VIII associated antigen in combined factor V and factor VIII deficiency.

The behavior of factor VIII associated antigen of three patients with combined factor V and factor VIII deficiency has been evaluated in several immunological systems. Factor VIII associated antigen resulted to be normal or higher than normal in all three patients in the radial immunodiffusion and in the electroimmunoassay systems. In the bidimensional electrophoresis system only one factor VIII precipitate was evident and such factor VIII precipitate showed the same electrophoretic mobility as normal factor VIII antigen. These findings firmly establish the fact that the factor VIII defect in congenital combined factor V and factor VIII deficiency is of the hemophilia type.