Heterogeneity of sugar composition of factor VIII/von Willebrand factor in von Willebrand's disease: analysis by crossed affinoimmunoelectrophoresis using lectin (ricinus communis agglutinin-120).

The nature of sugar chain of factor VIII/von Willebrand factor in plasma of normal subjects and patients with von Willebrand's disease (vWd) was examined by crossed affinoimmunoelectrophoresis using anti-human factor VIII rabbit serum, with inserted Ricinus communis agglutinin-120 (RCA-120) agarose layer (RCA - CIE). Molecular weights of factor VIII-related antigen (VIIIR:Ag) were estimated by SDS polyacrylamide gel electrophoresis - crossed affinoimmunoelectrophoresis (SDS PAGE - RCA - CIE). VIIIR:Ag, in normal plasma and in classical form of vWd, showed two precipitin peaks on RCA - CIE. The slower moving component of VIIIR:Ag with molecular weights over 3 x 10(6) daltons from normal subjects and patients with classical form of vWd showed a high affinity for RCA-120. The faster moving component of VIIIR:Ag below 3 x 10(6) daltons from the above-mentioned subjects and patients with a variant form (Type IIA) showed a very weak affinity for RCA-120. These results suggested that all of VIIIR:Ag in these variant cases may have a deficiency of galactose residues reactive with RCA, in addition to an incomplete polymerization of VIIIR:Ag, similar to that of the faster moving component of normal subjects.