[Hyperlipoproteinemia in liver diseases].
Disorders of liver function frequently lead to raised plasma lipid values. The methods for analyzing plasma lipids and lipoproteins developed in recent years have yielded a great deal of data. This information provides new insights into the interrelationships of these disorders and are furthermore important in differential diagnosis of jaundice. An abnormal lipoprotein (LP-X) has been isolated from the plasma of patients with intra- or extrahepatic cholestasis, and a simple and sensitive method of demonstrating this lipoprotein has subsequently been developed. This parameter is today the surest clinico-chemical test for excluding or demonstrating cholestasis, triglyceride-rich lipoproteins accumulate in the plasma due to lack of lipase. This leads to hypertriglyceridemia. The disappearance of pre-beta and alpha-lipoprotein bands in agarose gel electrophoresis, which is a most frequent sign of severe liver damage (irrespective of its origin) is probably caused by a defective lipoprotein A. The capacity of lipoprotein A to bind certain lipid fractions is reduced or abolished. By no means all the mechanisms leading to structural changes in plasma lipoproteins and hyperlipoproteinemia in disorders of liver function are known at present. However, new findings emphasize the central role played by the liver in synthesis and degradation of plasma lipoproteins.