Plasma lecithin:cholesterol acyltransferase activity and the lipoprotein abnormalities of liver disease.

Abstract

Patients with liver disease have low, normal, or high plasma lecithin:cholesterol acyltransferase (LCAT)activity. Total plasma lipids are usually low with parenchymal liver disease but high with obstructive jaundice. We hypothesized that plasma lipoprotein abnormalities would reflect plasma LC AT activity. In obstructive jaundice plasma lipids were high, but in parenchymal liver disease they were significantly reduced only when LCAT activity was low. In both groups of patients the composition of the individual lipoprotein fractions (i.e. VLDL. LDL and HDL) was normal when plasma LCAT was high, with a normal electrophoretic pattern. With obstructive jaundice and low LCAT activity VLDL ran with P mobility and contained less triglyceride. Three LDL particles were found: LP-X, large triglyceride-rich particles, and normal-sized particles with more triglyceride and less cholesteryl ester than usual. Stacked discs were found in the HDL. With parenchymal liver disease and low LCAT activity VLDL and HDL concentrations were low and HDL stacked discs were found. Only one LDL particle, of normal size and concentration, was found; it was triglyceride-rich and cholesteryl ester poor. The results suggest that many of the lipoprotein abnormalities of liver disease are a consequence of reduced plasma LCAT activity.