CHYLOMICRON-LIKE PARTICLES IN SEVERE HYPERTRIGLYCERIDEMIA

Plasma lipoproteins in a diabetic patient with severe hypertriglyceridemia and turbid, milky plasma were studied and compared with those found in 3 primary type V hyperlipoproteinemic and in 3 normal subjects after a fatty meal. All subjects had normal post-heparin lipolytic activity. Lipoprotein electrophoresis of the patient''s plasma revealed no chylomicron band, and upon short-time ultracentrifugation the patient''s supernatant showed most lipid staining in the pre-.beta.-lipoprotein region. This supernantant, which in type V hyperlipoproteinemia as well as in normal subjects after a fatty meal, contains a large proportion of apolipoprotein B-48 (of intestinal origin), was found in this patient to contain mostly apolipoprotein B-100 (of liver origin). Upon incubation of normal washed platelets with chylomicrons derived either from type V hyperlipoproteinemic or from normal subjects after a fatty meal, platelet aggregation was decreased, whereas the chylomicron-like particles from the patient increased platelet actiivty. The triglyceride-rich, cholesterol-poor lipoproteins are probably of liver and not of intestinal origin.