Impaired Intermediate-Density Lipoprotein Triglyceride Hydrolysis in a Homozygote of Familial Lecithin: Cholesterol Acyltransferase (LCAT) Deficiency

Abstract

In fasting serum of familial lecithin: cholesterol acyltransferase (LCAT) deficient patient, existence of intermediate-dencity lipoprotein (IDL) fraction was observed. Triglyceride (TG) hydrolysis of the IDL fraction by hepatic TG lipase was lower than those of IDL fraction from normal post-prandial serum. That impairment was partially recovered by preincubation of the patient IDL with serum obtained from normal person. So, the impairment was suspected to be caused by an increase in free cholesterol on the surface of IDL particle, which is directly induced by LCAT deficiency in serum. Furthermore decreased activity of hepatic TG lipase in postheparin plasma might be involved in the retention of IDL fractions.