Heterogeneity of human factor VIII/vWF in lipaemic plasma

In order to determine the influence of plasma lipids on the apparent molecular size of human F VIII/vWF and on the relationship of the factor-related properties, namely F VIII:C, F VIIIR:Rcof, and F VIIIR:Ag to F VIII/vWF, the factor's elution pattern in the presence of lipids on Sephacryl 1000 was investigated. When fresh plasma of fasting donors was chromatographed on this gel, F VIII/vWF eluted in a single sharp peak with all three F VIII-related activities appearing in the separation range of the gel column. When fresh postprandial lipaemic plasma was chromatographed on this gel, F VIII/vWF showed distinct heterogeneity in the elution pattern with respect to molecular size and relationship to the F VIII-related properties. After incubation of lipaemic plasma with phospholipase C the elution pattern of F VIII/vWF changed from heterogeneity to homogeneity similar to those of plasma of fasting donors. After incubation of lipaemic plasma with triglycerid lipase the elution pattern of F VIII/vWF remained heterogenous. A similar heterogeneity in the elution pattern of F VIII/vWF was found when plasma of fasting donors was mixed with a preparation of very low density lipoproteins derived from human postprandial plasma or with a preparation of coagulant-active phospholipids.