Dispersity of human factor VIII - Von Willebrand factor

Abstract Human factor VIII — Von Willebrand factor purified by gel chromatography in the presence of dextran has been studied with large pore polyacrylamide gel electrophoresis designed for analysis of highmolecular-weight proteins. It was demonstrated that purified factor VIII-Von Willebrand factor is not a single homogeneous entity, but consists of a series of immunologically related polymers. The polydispersity of factor VIII-Von Willebrand factor was confirmed by an immunochemical variant of the reversal-electrophoresis spreading test. With this technique it could be visualized that also factor VIII in plasma and cryoprecipitate is polydisperse in nature. As a consequence, changes in the polymer distribution of factor VIII-Von Willebrand factor can be an alternative explanation for results of dissociation experiments and for abnormalities in various diseases as demonstrated by cross-immunoelectrophoresis.