Selectivity of LDL removal by double filtration (DF) and dextran-sulfate cellulose (DSC) column plasmapheresis (PP) was compared in six heterozygous familial hypercholesterolemic (FH) and a non-familial type IIb hyperlipoproteinemic patients. And, probucol, cholestyramine or CS 514, a newly developed inhibitor of HMG-Co A reductase was tested to elongate PP intervals. Two and half liters of plasma were treated at each PP. DFPP or DSC column PP was purformed alternatively to each patient. Probucol (1g/day), cholestyramine (12g/day) or CS 514 (10-20mg/day) was administered after PP without any combination. Plasma total cholesterol (TC), TG, VLDL-C, LDL-C, HDL-C and apoproteins A-I, A-II, B, C-II, C-III, E were measured serially. Lipoproteins were separated by ultracentrifugation and apoproteins were measured by RID method.
Sixty five percent of LDL-C, 45% of HDL-C, 43% of apo A-I, 65% of apo B, 56% of apo C-II, 54% of apo C-III and 75% of apo E were removed on average by DFPP with a second membrane filter of average pore diameter 300Å. The removal rate of LDL-C was significantly higher than that of HDL-C by DFPP. Fifty nine percent of LDL-C, 0% of HDL-C, 12% of apo A-I, 11% of apo A-II, 61% of apo B, 50% of apo C-II, 50% of apo C-III and 85% of apo E were removed on average by DSC column PP. Therefore, the selectivity of LDL removal was much better by DSC column PP than by DFPP. Plasma TC reached 250mg/dl within a week and 280mg/dl within 2 weeks without medication. On probucol treatment, it reached 250mg/dl between 13 and 16 days, and 280mg/dl between 26 and 41 days. TC reached 280mg/dl between 48 and 56 days on cholestyramine. On CS 514, it reached 250mg/dl between 8 days and days longer than 84, and reached 280mg/dl between 11 days and days longer than 84 days.
We concluded that plasma TC of heterozygous FH could be kept normal for long time by the combination therapy with PP and drugs.