Lp(a)の血清リポ蛋白亜分画分布

Abstract

Plasma levels of lipoprotein (a) (Lp(a)) in lipoprotein subtractions were compared in hyperlipoproteinemias. Thirty-two normolipoproteinemic subjects and 30 type IIa, 30 type IIb, and 20 type IV patients were enrolled in this study. Lipoproteins were subfractionated into VDLD, IDL, LDL1 (1.019<d<1.045), LDL2 (1.045<d<1.063), HDL2, and HDL3+Bottom (B) (d>1.125) by sequential ultracentrifugation. Lp(a) was measured by the ELISA method using Biopool kits. Seventy-five percent of Lp(a) in HDL+B was recovered in the bottom fraction. Plasma VLDL-Lp(a) concentrations were 0.76±0.54 (mean±SD) mg/dl in normal, 1.16±1.50mg/dl in type IIa, 0.73±0.63mg/dl in type IIb and 0.62±0.67mg/dl in type IV subjects. IDL-Lp(a) levels were 0.52±0.68mg/dl in normal, 0.90±1.20mg/dl in type IIa, 0.51±0.48mg/dl in type IIb and 0.29±0.35mg/dl in type IV subjects. Plasma LDL1-Lp(a) concentrations were 0.89±0.80 mg/dl in normal, 1.10±1.66mg/dl in type IIa, 0.56±0.43mg/dl in type IIb and 0.65±0.77mg/dl in type IV subjects. Plasma LDL2-Lp(a) levels were 2.07±4.21mg/dl in normal, 2.94±5.07mg/dl in type IIa, 1.31±1.21mg/dl in type IIb and 1.70±3.96mg/dl in type IV subjects. Plasma HDL2-Lp(a) concentrations were 6.56±9.31mg/dl in normal, 9.32±11.68mg/dl in type IIa, 4.57±4.46mg/dl in type IIb and 4.00±4.96mg/dl subjects. Plasma HDL3+Bottom-Lp(a) levels were 3.10±5.13mg/dl in normal, 3.19±3.48mg/dl in type IIa, 1.47±1.25mg/dl in type IIb and 1.51±1.73mg/dl in type IV subjects. There were no significant differences in plasma lipoprotein subfraction Lp(a) levels among the 4 groups.There was a significant correlation between the plasma HDL2-cholesterol and HDL2-Lp(a) levels (r=0.427, P<0.01). This finding suggest the presence of some metabolic relationships between HDL2 and Lp(a) recovered in the density range between 1.063 and 1.125.