Gel filtration patterns of factor VIII coagulant antigen and factor VIII related antigen in normal and von Willebrand's disease.

Gel filtration (sepharose 2B CL) patterns of factor VIII coagulant antigen (VIIIC:Ag) and factor VIII related antigen (VIIIR:Ag) were obtained using normal plasma and plasma from patients with von Willebrand's disease. The latter group consisted of five individuals with normal mobility of factor VIIIR:Ag on cross-immunoelectrophoresis (Type I) and five others with abnormal (increased) mobility (Type II). Results showed that the elution of VIIIC:Ag was delayed in those subjects whose ratio of VIIIR:Ag to VIIIC:Ag was reduced. It has previously been reported that VIIIR:Ag exerts a stabilizing influence on the coagulant activity of factor VIII (VIII:C); our data suggests that when VIIIR:Ag is deficient, abnormal (low molecular weight) forms of VIIIC:Ag circulate.