[The detection of apolipoproteins AI and B in the liver of patients with and without hyperlipoproteinemia (author's transl)].

Liver sections as well as isolated liver cells from 5 patients with a normal liver and normal serum lipids and patients with familial hyperlipoproteinemia type IIa (n=6), type IIb (n=11), type IV (n=13) and type V (n=2) were studied for the presence of apolipoprotein (apo) AI and B by immunofluorescence technique. At the time of liver biopsy the actual serum concentrations of HDL- and LDL-cholesterol and triglycerides were determined. In patients without metabolic disturbances apo AI was detectable in hepatocytes in 2 out of 5 cases. Apo B was not found in the liver of these patients. The non-parenchymal liver cells did not show depositions of apoproteins. In the group of 32 patients with hyperlipoproteinemia 6 cases showed in the liver apo AI and 2 cases apo B. The apoproteins exhibited a granular fluorescence pattern in the cytoplasm of hepatocytes. There was no correlation between the apoproteins in the liver and the degree of fat depositions in hepatocytes or the concentrations of serum lipids. The results indicate that the fat droplets in hepatocytes of patients with hyperlipoproteinemia represent lipid particles free of apoproteins. The lack of apoproteins in the liver with elevation of lipids in serum can be explained with a disturbed hepatic clearance function for lipoproteins.